Volunteer Estuary Monitoring
 A Methods Manual 

Second Edition 
Volunteer Estuary Monitoring A Methods Manual

Second Edition
U.S. Environmental Protection Agency

Office of Wetlands, Oceans, and Watersheds

Volunteer Monitoring (4504T)

1200 Pennsylvania Avenue, NW

Washington, DC 20460

Phone: 202-566-1200

Fax: 202-566-1336

E-mail: OW-General@epamail.epa.gov

The Ocean Conservancy

2029 K Street, NW

Suite 500

Washington, DC 20006

Phone: 202-429-5609

Fax: 202-972-0619

Web: www.oceanconservancy.org

Volunteer Estuary Monitoring A Methods Manual

Second Edition

Ronald L. Ohrel, Jr.

The Ocean Conservancy

Kathleen M. Register

Clean Virginia Waterways

and Longwood University
COVER PHOTOS:

Top row (l to r): The Ocean Conservancy, K. Register, The Ocean Conservancy, R. Ohrel

Row 2 (l to r): K. Register, S. Schultz, Weeks Bay Watershed Project, K. Register

Row 3 (l to r): L. Monk, The Ocean Conservancy, S. Schultz, E. Ely

Row 4 (l to r): T. Monk, The Ocean Conservancy, The Ocean Conservancy, R. Ohrel

This document was prepared under Cooperative Agreement #CX825019-01-3 from the U.S. Environmental Protection

Agency (EPA), Office of Wetlands, Oceans and Watersheds to The Ocean Conservancy.

Second Reprint 2006, ©2002 The Ocean Conservancy.

NOTICE:

This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved

for publication. Mention of trade names or commercial products does not constitute endorsement 

or recommendation for use.

Printed on recycled paper using soy-based inks.
iii

Volunteer Estuary Monitoring: A Methods Manual

Acknowledgements

U.S. Environmental Protection Agency Project Officer: Joseph N. Hall, II

The Ocean Conservancy Project Director: Seba B. Sheavly

Editors and Primary Contributors: 

Ronald L. Ohrel, Jr., The Ocean Conservancy

Kathleen M. Register, Clean Virginia Waterways and Longwood College

Proofreader: Elaine Hruska

Document Design and Graphics (except where indicated): Critical Stages

The author of the first edition of this document in 1993 was Nina A. Fisher.

The Ocean Conservancy is the nation's leading nonprofit organization dedicated solely to protecting

ocean environments and marine life in all its abundance and diversity. As part of a cooperative

agreement with the U.S. Environmental Protection Agency (EPA), The Ocean Conservancy conducted

a series of train-the-trainer workshops on monitoring estuary environments. Workshop attendees

provided valuable comments on the first edition of this manual, which helped guide the revision. We

thank them for their time and input.

In addition, the following estuary monitoring experts and volunteer monitoring program coordinators

contributed significantly to this project by submitting case studies and other information:

Charles Barr, The Ocean Conservancy; Peter Bergstrom, U.S. Fish and Wildlife Service

(Chesapeake Bay Field Office); Eve Brantley, Weeks Bay Watershed Project; Amber Cornell,

Adopt A Beach; Carol Elliott, Alliance for a Living Ocean; Eleanor Ely, The Volunteer Monitor;

Jon Graves, Portland State University; Holly Greening, Tampa Bay Estuary Program; Kerry

Griffin, Tillamook Bay National Estuary Project; Linda Hanson, Washington State Department

of Health; Paul Heimowitz, Oregon State University Extension Sea Grant; Philip L. Hoffman,

Tampa BayWatch, Inc.; Harold G. Marshall, Ph.D., Old Dominion University; Lisa Monk, The

Ocean Conservancy; Stacey Moulds, Alliance for the Chesapeake Bay; Bob Murphy, Alliance

for the Chesapeake Bay; Seba B. Sheavly, The Ocean Conservancy; and Esperanza Stancioff,

University of Maine Cooperative Extension. Portions of this document were excerpted and

adapted from other authors, which are referenced in each chapter.

The editors also wish to thank the reviewers who offered valuable comments on this document: 

Cathy Barnette, Dauphin Island Sea Lab/Alabama Department of Economic and Community

Affairs; Charles Barr, The Ocean Conservancy; Peter Bergstrom, U.S. Fish and Wildlife

Service (Chesapeake Bay Field Office); Beth Biermann, The Ocean Conservancy; Eleanor

Bochenek, Ph.D., New Jersey Sea Grant; Eve Brantley, Weeks Bay Watershed Project; David

Buckalew, Ph.D., Longwood College; Barry Burgan, EPA; Diane Calesso, EPA Region 2; Kim

Donahue, Chesapeake Bay Foundation; Carol Elliott, Alliance for a Living Ocean; Eleanor Ely,

The Volunteer Monitor; Joe Farrell, Delaware Sea Grant; Iraida Garcia, Jobos Bay National

Estuarine Research Reserve; Holly Greening, Tampa Bay Estuary Program; Dominic Gregorio,

California State Water Resources Control Board; Kerry Griffin, Tillamook Bay National Estuary

Project; Joseph N. Hall, II, EPA; Paul Heimowitz, Oregon State University Extension Sea Grant;

Mark Kutnink, EPA Region 9; George Loeb, EPA; Harold G. Marshall, Ph.D., Old Dominion

Acknowledgements
iv

Volunteer Estuary Monitoring: A Methods Manual

Acknowledgements

University; Alice Mayio, EPA; Gerri Miceli, Gordon Research Conferences; Clara Mojica,

Ph.D., Jobos Bay National Estuarine Research Reserve; Lisa Monk, The Ocean Conservancy;

Bob Murphy, Alliance for the Chesapeake Bay; Paul Pan, EPA; Jonathan Phinney, Ph.D.,

American Society of Limnology and Oceanography; Dominic Roques, California State Water

Resources Control Board; Tamara Saltman, EPA; Kathleen Sayce, ShoreBank Pacific;

Donald Schulz, Surfrider Foundation (Huntington/Seal Beach Chapter); Seba B. Sheavly, The

Ocean Conservancy; Linda Sheehan, The Ocean Conservancy; Frederick Short, Ph.D.,

University of New Hampshire; Esperanza Stancioff, University of Maine Cooperative

Extension; Edward Stets, EPA; Terry Tamminen, Environment Now; Marie-Francoise

Walk, Massachusetts Water Watch Partnership; Robert Warren, Columbia River Estuary Study

Taskforce (CREST); and Karen Font Williams, Oregon Department of Environmental Quality.

Finally, we would like to thank those individuals and organizations who provided photographs for

inclusion in this document:

Peter Bergstrom, Gerrit Carver, Eleanor Ely, Maine Department of Marine Resources, Lisa

Monk, Tim Monk, Bob Murphy, The Ocean Conservancy, PhotoDisc, Ronald Ohrel, M.

Redpath, Kathleen Register, Sheila Schultz, Tillamook Bay National Estuary Project and

Battelle Marine Science Lab, U.S. Environmental Protection Agency, University of Maine

Cooperative Extension, and Weeks Bay Watershed Project.

Acknowledgements continued
v

Volunteer Estuary Monitoring: A Methods Manual

Table of Contents

Acknowledgements ........................................................................................................................iii

Table of Contents.............................................................................................................................v

Executive Summary .......................................................................................................................xi

Chapter 1: Introduction

Where Would Estuaries Be Without Volunteer Monitors? ...........................1-1

About the Manual..........................................................................................1-1

Purpose of the Manual ..................................................................................1-2

Organization of the Manual ..........................................................................1-2

How to Use the Manual ................................................................................1-4

References and Further Reading ...................................................................1-4

Chapter 2: Understanding Our Troubled Estuaries

Overview .......................................................................................................2-1

The Science ...................................................................................................2-2

The Problems.................................................................................................2-5

The Solutions.................................................................................................2-8

References and Further Reading .................................................................2-14

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program

Overview .......................................................................................................3-1

Establishing Goals and Objectives................................................................3-2

Insurance, Safety, and Liability—Risk Management ...................................3-6

Paying for the Program—The Financial Side...............................................3-7

Promoting the Program—Working with the Media....................................3-12

References and Further Reading .................................................................3-15

Chapter 4: Recruiting, Training, and Retaining Volunteers

Overview .......................................................................................................4-1

Recruiting Volunteers ....................................................................................4-2

Training Volunteers .......................................................................................4-3

Retaining Volunteers ...................................................................................4-11

References and Further Reading .................................................................4-14

Chapter 5: Quality Assurance Project Planning

Overview .......................................................................................................5-1

The Importance of High Quality Data ..........................................................5-2

What Is a Quality Assurance Project Plan? ..................................................5-2

Why Develop a QAPP?.................................................................................5-3

Basic Concepts ..............................................................................................5-4

Quality Control and Assessment .................................................................5-10

Developing a QAPP ....................................................................................5-13

Elements of a QAPP ...................................................................................5-17

References and Further Reading .................................................................5-22

Table of Contents
vi

Volunteer Estuary Monitoring: A Methods Manual

Table of Contents

Chapter 6: Sampling Considerations

Overview .......................................................................................................6-1

Four Critical Questions.................................................................................6-2

References and Further Reading ...................................................................6-7

Chapter 7: In the Field

Overview .......................................................................................................7-1

Fun in the Field .............................................................................................7-2

Before Leaving Home ...................................................................................7-3

Safety Considerations....................................................................................7-3

What to Bring................................................................................................7-9

Locating Monitoring Sites, or How Do I Get There from Here? ...............7-10

Making Field Observations: Visual Assessments .......................................7-12

Helpful Field Measurements.......................................................................7-14

How to Collect Samples..............................................................................7-15

The Data Form ............................................................................................7-17

References and Further Reading .................................................................7-18

Chapter 8: Data Management, Interpretation, and Presentation

Overview .......................................................................................................8-1

After Data Collection: What Does it Mean?.................................................8-2

Data Management .........................................................................................8-2

Data Interpretation.........................................................................................8-7

Data Presentation.........................................................................................8-10

References and Further Reading .................................................................8-18

Unit One: Chemical Measures

Chapter 9: Oxygen

Overview .......................................................................................................9-1

Why Monitor Oxygen? .................................................................................9-2

Dissolved Oxygen (DO)................................................................................9-2

Sampling Considerations..........................................................................9-4

How to Monitor Dissolved Oxygen..........................................................9-7

Biochemical Oxygen Demand (BOD)........................................................9-14

Sampling Considerations........................................................................9-14

How to Measure Biochemical Oxygen Demand....................................9-15

References and Further Reading .................................................................9-16

Chapter 10: Nutrients

Overview .....................................................................................................10-1

Why Monitor Nutrients? .............................................................................10-2

Sampling Considerations.............................................................................10-5

How to Monitor Nutrients...........................................................................10-8

Special Topic: Atmospheric Deposition of Nutrients................................10-11

References and Further Reading ...............................................................10-13
vii

Volunteer Estuary Monitoring: A Methods Manual

Table of Contents

Chapter 11: pH and Alkalinity

Overview .....................................................................................................11-1

Why Monitor pH and Alkalinity? ...............................................................11-2

pH ................................................................................................................11-2

Sampling Considerations........................................................................11-3

How to Measure pH Values....................................................................11-5

Total Alkalinity............................................................................................11-6

Sampling Considerations........................................................................11-7

How to Measure Alkalinity.....................................................................11-7

References and Further Reading ...............................................................11-10

Chapter 12: Toxins

Overview .....................................................................................................12-1

Toxins in Estuaries......................................................................................12-2

Why Monitor Toxins? .................................................................................12-2

The Role of Toxins in the Estuary Ecosystem............................................12-3

Sampling Considerations.............................................................................12-7

Atmospheric Deposition of Toxins .............................................................12-8

References and Further Reading .................................................................12-8

Unit Two: Physical Measures

Chapter 13: Temperature

Overview .....................................................................................................13-1

Why Monitor Temperature? ........................................................................13-2

Sampling Considerations.............................................................................13-2

How to Monitor Temperature......................................................................13-3

References and Further Reading .................................................................13-5

Chapter 14: Salinity

Overview .....................................................................................................14-1

About Salinity .............................................................................................14-2

Sampling Considerations.............................................................................14-3

How to Measure Salinity.............................................................................14-5

References and Further Reading .................................................................14-7

Chapter 15: Turbidity and Total Solids

Overview .....................................................................................................15-1

Why Measure Turbidity and Total Solids? .................................................15-2

Sampling Considerations.............................................................................15-3

How to Measure Turbidity ..........................................................................15-7

How to Measure Total Solids....................................................................15-10

References and Further Reading ...............................................................15-10
viii

Volunteer Estuary Monitoring: A Methods Manual

Table of Contents

Chapter 16: Marine Debris

Overview .....................................................................................................16-1

Why Monitor Marine Debris?.....................................................................16-2

Sampling Considerations and Options........................................................16-5

How to Conduct a Marine Debris Cleanup.................................................16-7

References and Further Reading ...............................................................16-13

Unit Three: Biological Measures

Chapter 17: Bacteria: Indicators of Potential Pathogens

Overview .....................................................................................................17-1

Why Monitor Bacteria?...............................................................................17-2

The Bacterial Indicators..............................................................................17-4

How Effective Are the Indicators?..............................................................17-6

Bacterial Sampling and Equipment Considerations ...................................17-6

In the Field: Collecting Water Samples for Bacterial Analysis..................17-8

In the Lab: Analytical Methods.................................................................17-10

Which Method and Which Medium Should You Use?.............................17-14

References and Further Reading ...............................................................17-19

Chapter 18: Submerged Aquatic Vegetation

Overview .....................................................................................................18-1

Why Monitor SAV?.....................................................................................18-2

Sampling Considerations.............................................................................18-4

How to Groundtruth ..................................................................................18-10

References and Further Reading ...............................................................18-14

Chapter 19: Other Living Organisms

Overview .....................................................................................................19-1

Why Monitor Other Living Organisms?.....................................................19-2

Macroinvertebrates......................................................................................19-2

Shellfish Sampling Considerations.........................................................19-5

How to Collect Shellfish.........................................................................19-5

Phytoplankton..............................................................................................19-7

Sampling Considerations......................................................................19-10

How to Monitor Phytoplankton............................................................19-12

Special Topic: Chlorophyll Collection for Lab Analysis .....................19-16

Non-Indigenous Species............................................................................19-16

Sampling Considerations......................................................................19-18

How to Monitor Non-Indigenous Species............................................19-19

References and Further Reading ...............................................................19-22
ix

Volunteer Estuary Monitoring: A Methods Manual

Table of Contents

Appendices

Appendix A: Sample Data Forms...............................................................................................A-1

Appendix B: Resources...............................................................................................................B-1

Appendix C: Equipment Suppliers..............................................................................................C-1

Glossary and Acronyms ...........................................................................................................GA-1

Index .............................................................................................................................................I-1
x

Volunteer Estuary Monitoring: A Methods Manual
xi

Volunteer Estuary Monitoring: A Methods Manual

Executive Summary

This manual focuses on volunteer estuary monitoring. As concern over the well-being of the

environment has increased during the past couple of decades, volunteer monitoring has become an

integral part of the effort to assess the health of our nation’s waters. Government agencies, often

strapped by financial limitations, have found that volunteer programs can provide high-quality, reliable

data to supplement their own water quality monitoring programs.

It may seem obvious, but should nonetheless be stated: without individual volunteers who commit

their time and energy to the effort, there would be no volunteer monitoring programs. As people

learn more about how an estuary functions and come to recognize its signs of distress, their concern for

its future is increased. So too is their commitment to its protection. 

Thus, volunteer monitoring of estuaries has grown significantly from the early programs that monitored

only a few simple parameters. As these monitoring programs have developed, so has the interest of the

Environmental Protection Agency (EPA), which has supported volunteer monitoring since 1987. The

EPA sponsors national symposia on volunteer monitoring, publishes a newsletter for volunteers, has

developed guidance manuals and a directory of volunteer organizations, and provides technical support

to volunteer programs. Through these efforts, the EPA hopes to foster the interest and support of state

and other agencies in these programs.

The EPA developed this manual as a companion to three other documents: 

• Volunteer Water Monitoring: A Guide for State Managers;

• Volunteer Lake Monitoring: A Methods Manual; and 

• Volunteer Stream Monitoring: A Methods Manual. 

This document presents information and methodologies specific to estuarine water quality. Both the

organizers of volunteer programs and the volunteers themselves should find it of use.

The first eight chapters of the manual deal with typical issues that a new or established volunteer

estuary monitoring program might face:

• understanding estuaries, what makes them unique, the problems they face, and the role of

humans in solving the problems;

• establishing and maintaining a volunteer monitoring program;

• working with volunteers and making certain that they are well-positioned to collect water 

quality data safely and effectively;

• ensuring that the program consistently produces data of high quality; and

• managing the data and making it available to data users.

Executive Summary
xii

Volunteer Estuary Monitoring: A Methods Manual

Executive Summary

The remaining chapters focus on several water quality parameters that are important in determining

the health of an estuary. These chapters are divided into three units, which characterize the

parameters as measures of the chemical, physical, or biological environment of the estuary.

The significance of each parameter and specific methods to monitor it are detailed in a step-by-step

fashion. The manual stresses proper quality assurance and quality control techniques to ensure that

the data are useful to state agencies and any other data users.

References are listed at the end of each chapter. Appendices containing additional resources are also

supplied. These references should prove a valuable source of detailed information to anyone

interested in establishing a new volunteer program or a background resource to those with already

established programs.
Chapter 1 Introduction

The inspiration for this manual comes from the people who are dedicated to

monitoring estuaries and the environment around them. The people who create

volunteer monitoring programs and the people who serve as volunteer monitors

care deeply about their estuaries, are concerned about their watersheds, and want

the opportunity for more community involvement.
Photos (l to r): S. Schultz, T. Monk, S. Schultz
1-1

Volunteer Estuary Monitoring: A Methods Manual

Chapter 1: Introduction

The inspiration for this manual comes from

the people who are dedicated to monitoring

estuaries and the environment around them.

The people who create volunteer monitoring

programs and the people who serve as

volunteer monitors care deeply about their

estuaries, are concerned about their

watersheds, and want the opportunity for more

community involvement. 

Estuary volunteer monitoring programs give

men, women, and children a priceless

opportunity to intimately know the many

spectacular riches of the estuarine

environment. As people learn more about how

an estuary functions and come to recognize its

signs of distress, their concern for its future is

increased. So too is their commitment to its

protection. The fact is, we will take care of

something when we value it. 

Volunteer estuary monitoring programs can

create citizen leaders

who work to reduce

pollution, increase

education, and better

manage our coastal

areas, all with the

purpose of protecting

some very special

places.

By donating their

time and talents to a

monitoring program,

volunteers offer a

priceless, enduring

legacy to the future. We

are collectively responsible for the

preservation our natural world for the future

generations of people, animals and plants that

call an estuary “home.” ■

Where Would Estuaries Be Without Volunteer Monitors?

About the Manual 

Volunteer Estuary Monitoring: A Methods

Manual is a companion document to

Volunteer Water Monitoring: A Guide for

State Managers, published in 1990 by the

U.S. Environmental Protection Agency (EPA).

The guide describes the role of volunteer

monitoring in state programs and details how

managers can best organize and administer

these monitoring programs. This manual

focuses on the concepts and plans developed

by the EPA guide and places them in a nutsand-bolts context specifically for volunteer

estuary monitoring programs. 

Two other EPA documents are also closely

allied with this manual: Volunteer Lake

Monitoring: A Methods Manual (1991) and

Volunteer Stream

Monitoring: A Methods

Manual (1997).

Together, these manuals

provide guidance on

volunteer water quality

monitoring in much of

our nation’s watersheds. 

This is the second

edition of Volunteer

Estuary Monitoring: 

A Methods Manual.

It updates information

and adds new topics

that have emerged since the first manual was

introduced in 1993. ■

Estuaries support a vast array of wildlife. Some

make estuaries their lifelong homes, while

others can be seen only during certain times 

of the year or during particular periods of 

their lives (photo by S. Schultz).

Estuaries are homes for wildlife, food suppliers,

gateways of commerce, and cultural mainstays.

They are also imperiled. Volunteer monitors

help preserve our estuarine resources (photo 

by S. Schultz).
1-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 1: Introduction

Organization of the Manual 

The overriding purpose of Volunteer Estuary

Monitoring: A Methods Manual is to serve as a

tool for volunteer leaders who want to launch a

new estuary monitoring program or enhance an

existing program. In the process, the manual

shows how volunteer groups can collect

meaningful data to assess estuarine health. 

The manual is not intended to mandate new

methods or override those currently being

used by volunteer monitoring groups. Instead,

it presents methods that have been adapted

from those used successfully by existing

volunteer estuary monitoring programs

throughout the United States. The manual

describes methodologies and techniques for

monitoring water quality parameters, starting

and maintaining a volunteer estuary

monitoring program, working with volunteers,

ensuring high quality data, and analyzing and

presenting the data following collection. ■

Purpose of the Manual

This manual is organized into 19 chapters.

Chapters 1-8 provide information about

estuaries, volunteers and volunteer monitoring

programs, and ensuring and managing data of

high quality. Chapters 9-19 address specific

water quality variables that volunteer

monitoring programs may elect to measure.

These chapters are grouped into chemical,

physical, and biological units. Finally,

appendices supply additional information.

A summary of the manual’s contents is

provided here.

Chapter 1: Introduction 

The introduction outlines the purpose of

this manual and its relationship to other

documents published by the EPA. It also

provides information about how and by whom

the manual should be used and explains plans

for making updated materials available in the

future. Finally, the introduction summarizes

the contents of the manual.

Chapter 2: Understanding Our Troubled

Estuaries 

This chapter introduces the concept of an

estuary and summarizes the major problems

plaguing our nation’s estuarine waters. It also

discusses the reasons for monitoring estuarine

water quality and how monitoring data can

ultimately help provide solutions to these

diverse problems. 

Chapter 3: Planning and Maintaining a

Volunteer Estuary Monitoring Program

This chapter covers the basics of planning,

implementing, and maintaining a volunteer

monitoring program so that it yields credible

data that will identify problems and assess

trends. Included in this chapter are

discussions on establishing goals, liability and

other risk management issues, and obtaining

financial support. This chapter also presents

guidance on developing a user-friendly data

form and working with the media to promote

your program activities.

Chapter 4: Recruiting, Training, and

Retaining Volunteers

This chapter discusses how to recruit, train,

and retain top-notch volunteers. It summarizes

potential sources of volunteers and provides

detailed information for volunteer

coordinators on training techniques that are

proven to produce knowledgeable and

enthusiastic volunteers. 
1-3

Volunteer Estuary Monitoring: A Methods Manual

Chapter 1: Introduction

Chapter 5: Quality Assurance Project

Planning 

This chapter addresses one of the most

difficult issues facing volunteer monitoring

programs: data credibility. It details the

importance of developing a quality assurance

project plan (QAPP) and summarizes the

steps involved. 

Chapter 6: Sampling Considerations

This chapter reviews four critical questions

that a volunteer program must address before

taking a single water sample: (1) What

parameters will the program monitor? (2)

How will the selected paratmeters be

monitored? (3) Where will the parameters be

monitored? (4) When will they be monitored?

Chapter 7: In the Field

This chapter addresses what happens when

volunteers leave their homes for the

monitoring sites. It makes points about safety,

the right use of equipment, finding the

monitoring sites, making general observations

about the site, collecting data, and completing

the data form.

Chapter 8: Data Management,

Interpretation, and Presentation 

This chapter discusses the elements of a

volunteer program that take place after

volunteers collect their data. It introduces data

management tools, discusses data

interpretation, and gives suggestions for

maximizing the distribution of your data.

Unit One: Chemical Measures

This unit describes several water quality

parameters that may be included in volunteer

monitoring programs. Water quality variables

highlighted include oxygen (Chapter 9),

nutrients (Chapter 10), pH and alkalinity

(Chapter 11), and toxins (Chapter 12). The

chapters supply information on sampling

considerations and guidance on monitoring.

Unit Two: Physical Measures

This unit provides monitoring guidance for

water quality variables that represent

measures of the estuary’s physical

environment. Temperature (Chapter 13),

salinity (Chapter 14), turbidity and total solids

(Chapter 15), and marine debris (Chapter 16)

are included.

Unit Three: Biological Measures

Living organisms can be useful indicators

of estuarine health. This unit includes

information about monitoring bacteria as

indicators of potential pathogens (Chapter

17), submerged aquatic vegetation (Chapter

18), and other biological parameters,

including macroinvertebrates, plankton, and

non-indigenous species (Chapter 19).

Appendices

Several appendices, referred to throughout

the manual, are also included. These sections

provide sample data forms (Appendix A),

additional resources not listed in the chapters

(Appendix B), and information on equipment

suppliers (Appendix C). A glossary and

acronyms section as well as an index are also

included. ■
1-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 1: Introduction

Intended Audience

This manual is intended to be a resource for

leaders of volunteer estuary monitoring

programs. Such programs may be managed by

environmental groups, educational

institutions, or government agencies. 

Individual volunteers will also find this

manual to be a valuable resource, although

some components may not apply to them.

Volunteer leaders may elect to photocopy and

distribute portions of the manual to volunteers

as educational supplements, training

reinforcement, or background materials.

Is the Manual the Answer to All Estuarine

Monitoring Needs?

Certainly not! It would be impossible to

provide monitoring methods that are

uniformly applicable to all estuaries or all

volunteer programs throughout the United

States. Factors such as geographic region,

program goals and objectives, and program

resources will all influence the specific

methods used by each group. This manual,

therefore, urges volunteer program

coordinators to work hand-in-hand with state

and local water quality professionals or other

potential data users in developing and

operating a volunteer monitoring program. 

This manual is only one resource for

volunteer programs. Many other resources are

available from government agencies and

volunteer monitoring programs. Some are

listed at the end of individual chapters and in

Appendix B.

A Lot of Help from Our Friends

Some portions of this manual draw

heavily from other resources. The editors

wish to give these sources their due

recognition and have listed them at the end

of each applicable chapter, separate from

other references.

Updates to the Manual

This manual is available in hard copy and

on the Internet. It is anticipated that periodic

updates will be made. While the updates will

be included in future print versions, they will

also be made available for downloading from

the Internet. By making updates available on

the Internet, it is anticipated that volunteer

groups can access new information sooner

than having to wait for a new print version of

the manual. ■

U.S. Environmental Protection Agency (USEPA). 1990. Volunteer Water Monitoring: A Guide 

for State Managers. EPA 440/4-90-010. August. Office of Water, Washington, DC. 78 pp.

U.S. Environmental Protection Agency (USEPA). 1991. Volunteer Lake Monitoring: A Methods

Manual. EPA 440/4-91-002. Office of Water, Washington, DC. 121 pp.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A

Methods Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

References and Further Reading

How to Use the Manual
Understanding Our Troubled Estuaries Chapter 2

To say that estuaries are valuable resources is a gross understatement. They are

among the most productive natural environments in the world and among the most

sought-after places for people to live. Estuaries support major fisheries, shipping,

and tourism. They sustain organisms in many of their life stages, serve as migration

routes, and are havens for threatened and endangered species. Associated wetlands

filter pollutants, dissipate floodwaters, and prevent land erosion. 
Photos (l to r): U.S. Environmental Protection Agency, R. Ohrel, Weeks Bay Watershed Project, R. Ohrel
2-1

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

To say that estuaries are valuable resources is a gross understatement. They are

among the most productive natural environments in the world and among the most

sought-after places for people to live. Estuaries support major fisheries, shipping, and

tourism. They sustain organisms in many of their life stages, serve as migration

routes, and are havens for threatened and endangered species. Associated wetlands

filter pollutants, dissipate floodwaters, and prevent land erosion. 

Yet, despite their value, estuaries are in trouble.

Nearly half of the U.S. population lives in coastal areas, which include the shores

of estuaries. Unfortunately, this increasing concentration of people is upsetting the

natural balance of estuarine ecosystems and threatening their integrity. Pollution,

habitat destruction, overfishing, wetland loss, and the introduction of non-indigenous

species are among the consequences of many human activities.

As concern over the well-being of the environment has risen during the past several

decades, so has the interest in gathering information about the status of estuaries.

Government agencies have limited funds for monitoring. As a result, volunteer

monitoring has become an integral part of the effort to assess the health of our

nation’s waters. Designed properly, volunteer programs can provide high-quality

reliable data to supplement government agencies’ water quality monitoring programs.

This chapter discusses our troubled estuaries. The estuarine environment is

described and several problems relating human activities to estuarine degradation are

investigated. Finally, the role of volunteer monitoring in identifying, fixing, or

preventing problems is examined.

Overview
2-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

What Is an Estuary? 

Unlike many features of the landscape that

are easily described, estuaries are transitional

zones that encompass a wide variety of

environments. Loosely categorized as the zone

where fresh and salt water meet and mix, the

estuarine environment is a complex blend of

continuously changing habitats. To qualify as

an estuary, a waterbody must fit the following

description: 

“a semi-enclosed coastal body of water which

has free connection with the open sea and

within which sea water is measurably diluted

with fresh water derived from land drainage” 

(Pritchard, 1967). 

The estuary itself is a rather well-defined

body of water, bounded at its mouth by the

ocean and at its head by the upper limit of the

tides. It drains a much larger area, however, and

pollutant-producing activities near or in

tributaries even hundreds of miles away may

still adversely affect the estuary’s water quality. 

While some of the water in an estuary flows

from the tributaries that feed it, the remainder

moves in from the sea. When fresh and salt

water meet, the two do not readily mix. Fresh

water flowing in from tributaries is relatively

light and overrides the wedge of more dense

salt water moving in from the ocean. This

density differential often causes layering or

stratification of the water, which significantly

affects both circulation and the chemical profile

of an estuary. 

Scientists often classify estuaries into three

types according to the particular pattern of

water circulation (Figure 2-1): 

• Highly Stratified Estuary 

The layering between fresh water from the

tributaries and salt water from the ocean is

most distinct in this type of estuary, although

some seawater still mixes with the surface

freshwater layer. To compensate for this

“loss” of seawater, there is a slow but

continual up-estuary movement of the salty

water on the bottom. 

• Moderately Stratified Estuary 

In this intermediate estuary type, mixing of

fresh and salt water occurs at all depths. With

this vertical mixing, salinity levels generally

increase toward the estuary mouth, although

the lower layer is always saltier than the

upper layer. 

• Vertically Mixed Estuary 

In this type of estuary, powerful mixing by

tides tends to eliminate layering altogether.

Salinity in these estuaries is a function of the

tidal stage. This tidal dominance is usually

observed only in very small estuaries. 

The Science

Fresh Water

0

0

10

10

20

20

30

30

Flood Tide Ebb Tide

Highly Stratified Estuary

Vertically Mixed Estuary

Moderately Stratified Estuary

Sea Water

Figure 2-1. Three types

of estuaries: highly

stratified, moderately

stratified, and vertically

mixed (adapted from

Levinton, 1982).

Numbers refer to salinity

in parts per thousand.
2-3

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

Rivers flow in a single direction, flushing

out sediments and pollutants. In estuaries,

however, there is a constant balancing act

between the up-estuary saltwater movement

and down-estuary freshwater flow. Rather than

quickly flushing water and pollutants through

its system, an estuary often has a lengthy

retention period. Consequently, waterborne

pollutants, along with contaminated sediment,

may remain in the estuary for a long time,

magnifying their potential to adversely affect

the estuary’s plants and animals. 

Other factors also play a role in the

hydrology of an estuary. Basin shape, mouth

width, depth, area, tidal range, surrounding

topography, and regional climate combine to

make each estuary unique.

Why Are Estuaries Important?

Estuaries are critical for the survival of many

species. Tens of thousands of birds, mammals,

fish, and other wildlife depend on estuarine

habitats as places to live, feed, and reproduce.

They provide ideal spots for migratory birds to

rest and refuel during their journeys. Many

species of fish and shellfish rely on the sheltered waters of estuaries as protected places to

spawn, giving estuaries the nickname “nurseries

of the sea.” Hundreds of marine organisms,

including most commercially valuable fish

species, depend on estuaries at some point during their development.

Besides serving as an important habitat for

wildlife, the wetlands that fringe many estuaries

perform other valuable services. Water draining

from upland areas carries sediments, nutrients,

and other pollutants. But as the water flows

through wetlands, much of the sediments and

pollutants are filtered out. This filtration process

creates cleaner and clearer water, which benefits both people and marine life. Wetland plants

and soils also act as natural buffers between the

land and ocean, absorbing floodwaters and dissipating storm surges. This protects upland

organisms as well as valuable real estate from

storm and flood damage. Salt marsh grasses,

mangrove trees, and other estuarine plants also

prevent erosion and stabilize the shoreline. 

Among the cultural benefits

of estuaries are recreation,

scientific knowledge,

education, and aesthetic

value. Boating, fishing,

swimming, surfing, and bird

watching are just a few of the

numerous recreational

activities people enjoy in

estuaries. They are often the

cultural centers of coastal

communities—focal points

for commerce, recreation,

history, customs, and

traditions. As transition zones

between land and ocean,

estuaries are invaluable

laboratories for scientists and

students, providing countless

lessons in biology, geology,

chemistry, physics, history,

and social issues. Estuaries

also provide a great deal of

aesthetic enjoyment for the

people who live, work, or

recreate in and around them. 

Finally, the tangible and direct economic

benefits of estuaries should not be overlooked.

Tourism, fisheries, and other commercial

activities thrive on the wealth of natural

resources that estuaries supply. Protected

estuarine waters also support important public

infrastructure, serving as harbors and ports vital

for shipping, transportation, and industry. Some

attempts have been made to measure certain

aspects of the economic activity that depends

on America’s estuaries and other coastal waters.

For example: 

• Estuaries provide habitat for more than

75 percent of America’s commercial fish

catch and for 80-90 percent of the

recreational fish catch (National Safety

Council’s Environmental Center, 1998).

Commercial and recreational fishing

contribute about $4.3 billion annually to

the U.S. economy, while related marine

industries add another $3 billion

annually (ANEP, 1998). 

Commercial and recreational activities in

estuaries generate billions of dollars for local

economies (photo by USEPA).

Wetlands, like this one in Virginia, provide

many valuable services. They remove

pollutants, absorb floodwaters, dissipate

storm surges, stabilize shorelines, 

and serve as habitat for many organisms 

(photo by R. Ohrel).
2-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

• Nationwide, commercial and

recreational fishing, boating, tourism,

and other coastal industries provide

more than 28 million jobs. Commercial

shipping alone employed more than

50,000 people as of January 1997

(National Safety Council’s

Environmental Center, 1998). 

• There are 25,500 recreational facilities

along the U.S. coasts—almost 44,000

square miles of outdoor public recreation

areas (NOAA, 1990). The average

American spends 10 recreational days on

the coast each year. In 1993, more than

180 million Americans visited ocean and

bay beaches—nearly 70 percent of the

U.S. population. Coastal recreation and

tourism generate $8 to $12 billion

annually (National Safety Council’s

Environmental Center, 1998). 

In short, estuaries provide us with a whole

suite of resources, benefits, and services.

Some of these can be measured in dollars and

cents; others cannot. Estuaries are

irreplaceable natural resources that must be

managed carefully for the mutual benefit of

all who enjoy and depend on them.

Where Land Meets Ocean

You may have heard the saying, “We all

live downstream.” This is a rather simple

statement intended to bring attention to

complex, intertwined processes affecting

water quality. Estuaries are the intermediary

between oceans and land (Figure 2-2);

consequently, these two factors influence their

physical, chemical, and biological properties. 

Estuaries are part of a larger collection of

geographic features that make up a watershed,

an area that drains surface bodies of water.

Importance of Estuaries

HABITAT: Tens of thousands of birds, mammals, fish, and other wildlife depend on

estuaries. 

NURSERY: Many marine organisms, most commercially valuable fish species included,

depend on estuaries at some point during their development. 

PRODUCTIVITY: A healthy, undisturbed estuary produces from four to ten times the

weight of organic matter produced by a cultivated cornfield of the same size. 

WATER FILTRATION: Water draining off upland areas carries a load of sediments and

nutrients. As the water flows through salt marsh peat and the dense mesh of marsh grass

blades, much of the sediment and nutrient load is filtered out. This filtration process creates

cleaner and clearer water. 

FLOOD CONTROL: Porous, resilient salt marsh soils and grasses absorb floodwaters and

dissipate storm surges. Salt marsh-dominated estuaries provide natural buffers between the

land and the ocean. They protect upland organisms as well as billions of dollars of human

real estate. 

ECONOMY: Estuary-dependant activities—recreation, shipping, fishing, and tourism—

generate billions of dollars each year.

CULTURE: Native Americans and early settlers depended on productive estuaries for

survival. Sheltered ports were essential for the transfer of goods and information from other

continents. Today, estuaries support a way of life valued by many.

(Excerpted from NERRS Web site: http://inlet.geol.sc.edu/nerrsintro.html.)
2-5

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

Watersheds generally include lakes, rivers,

wetlands, streams, groundwater recharge

areas, and the surrounding landscape, in

addition to estuaries.

Tributaries flow downstream through the

watershed for up to hundreds of miles. In

their journey, they pick up materials that

wash off the land or are discharged directly

into the water by land-based activities.

Eventually, the materials that the tributaries

accumulate are delivered to estuaries.

The types of materials that eventually enter

an estuary largely depend on how the land is

used. Undisturbed forests, for example, will

discharge considerably fewer pollutants than

an urban center or cleared agricultural field.

Surrounding land uses and land use decisions,

then, can have significant effects on an

estuary’s overall health. ■ 

ESTUARY

OCEAN

Figure 2-2. Estuaries 

are transitional zones

between land and the

ocean (redrawn from EPA

Web site: http://www.epa.

gov/owow/oceans/factshe

ets/fact5.html).

Changes to the coastal landscape have had

serious implications for estuarine health.

Estuaries are bombarded by several pollutant

sources, and their impacts can be severe.

Pollutant Sources

Wherever there is human activity, there is

usually a potential source of pollutants. Table 2-

1 and Figure 2-3 summarize some common

estuarine pollutants and their potential sources.

Estuarine pollution is generally classified as

either point source pollution or nonpoint

source pollution. Point source pollution

describes pollution that comes from a

discernible source, such as an industrial

discharge or wastewater treatment plant. Point

source pollution is usually identified as coming

from a pipe, channel, or other obvious

discharge point. Laws regulate point sources,

with limits placed on the types and quantities of

discharges to estuaries and other waterways.

Nonpoint source pollution (NPS), on the

other hand, comes from a variety of diffuse

sources that do not have

a single discharge point.

Examples include

stormwater runoff from

urban areas, marina

operations, farming,

forestry, and construction

activities; faulty or

leaking septic systems;

and atmospheric

deposition originating

from industrial

operations or vehicles. NPS pollution, which is

often hard to identify and quantify, is generally

more difficult and expensive to regulate and

control than point source pollution.

Pollutant Impacts

Many of our nation’s more than 100

estuaries are also under siege. Historically,

estuaries and other waterbodies have been the

receptacles for society’s wastes. Human

sewage, industrial byproducts, and runoff

The Problems 

Point sources deliver pollutants to estuaries

through a pipe or other discharge point. Here, the

pipe is located under a pier (photo by R. Ohrel).
2-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

from farming operations

disappeared as they mixed with

receiving waters and washed into

the nation’s fragile estuaries. 

Over the past several decades,

however, the signs of estuarine

decline have become increasingly

apparent. Many fish and shellfish

populations hover near collapse.

Although we have recognized the

problems and have generally

reduced the pollutants entering our waters, the

sheer numbers of people living near the coasts

continue to stress our estuaries, lagoons, and

other coastal waters. 

No coastal areas, estuaries included, are

immune to the threat of pollution; they all

share common problems. Many are often

subject to seasonal depletion of dissolved

oxygen, particularly in their deeper waters.

Accelerated eutrophication—a condition in

which high nutrient concentrations stimulate

excessive algal blooms, which then deplete

dissolved oxygen as they decompose—often

threatens the character of the natural system.

Across the country, estuaries are vulnerable

to assault from a wide variety of toxic

substances, which menace the health of

humans and wildlife. While sources of these

substances may be relatively scarce in the

more pristine areas surrounding an estuary,

industrialized areas often lead to “hot spots”

in the adjacent estuary, with toxins

concentrating in the water, sediment, and

local aquatic plants and animals. Stormwater

runoff from urban and rural areas can also

deliver toxic materials to estuaries. Metals,

pesticides, and automotive fluids are

frequently washed from lawns, agricultural

fields, parking lots, marinas, and a myriad of

other sources to estuarine waters.

Bacterial contamination is yet another

Table 2-1. Common pollutants and impacts associated with selected coastal land uses (adapted from USEPA, 1997; Maine DEP, 1996; USEPA, 1993).

Possible Impacts

Reduced water clarity, smothered benthic habitat, toxicity to organisms,

excessive algal growth, reduced dissolved oxygen, water temperature changes

Possible introduction of pathogens, reduced water clarity, smothered benthic

habitat, excessive algal growth, reduced dissolved oxygen, water tempterature

changes

Reduced water clarity, smothered benthic habitat, water temperature changes

Reduced water clarity, smothered benthic habitat, impacts on pH and alkalinity

Reduced water clarity, smothered benthic habitat, impacts on pH and alkalinity,

toxicity to organisms

Reduced water clarity, excessive algal growth, reduced dissolved oxygen/higher

biochemical oxygen demand, water temperature and pH changes, possible

introuction of pathogens

Reduced water clarity, smothered benthic habitat, excessive algal growth,

reduced dissolved oxygen, water temperature changes, toxicity to organisms

Reduced water clarity, smothered benthic habitat, excessive algal growth,

reduced dissolved oxygen/higher biochemical oxygen demand, water

temperature changes, toxicity to organisms, possible introduction of pathogens

Reduced water clarity, smothered benthic habitat, excessive algal growth, reduced

dissolved oxygen/higher biochemical oxygen demand, toxicity to organisms

Excessive algal growth, reduced dissolved oxygen/higher biochemical oxygen

demand, water temperature changes, possible introduction of pathogens

Excessive algal growth, reduced dissolved oxygen/higher biochemical oxygen

demand, toxicity to organisms, possible introduction of pathogens

Source 

Cropland

Grazing land

Forestry

Mining

Industrial/commercial

discharge

Sewage treatment 

plants

Construction

Urban runoff

Lawns/golf courses

Septic systems

Marinas/boat usage

Common Pollutants

Sediments, nutrients,

pesticides

Fecal bateria, sediments,

nutrients

Sediments

Acid discharge, sediments

Sediments, toxins

Nutrients, suspended

solids, fecal bacteria

Sediments, toxins,

nutrients

Sediments, nutrients,

metals, petroleum

hydrocarbons, bacteria

Toxins, nutrients,

sediments

Fecal bacteria, nutrients

Toxins, nutrients, bacteria

Improperly managed construction sites

can clog estuaries with tons of

sediments (photo by R. Ohrel).
2-7

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

problem prevalent in many estuaries.

Inadequately treated sewage released to the

estuary threatens recreational water users and

contaminates local shellfish. States often

monitor shellfish or the waters overlying

shellfish beds for bacterial contamination,

occasionally shutting down contaminated areas

to recreational and commercial fishermen until

bacteria numbers drop to safe levels. 

Sediments from construction sites,

agricultural activities, forestry operations, and

dredging activities, among other sources, can

be another concern. Sediments washing into

estuaries or resuspended from dredging can

carry a host of additional environmental

problems with them. These sediments cover

critical benthic, or bottom, habitat for

numerous species and smother plants and

animals. They cloud waters, preventing

sunlight from reaching submerged plants.

Metals and other toxic materials are

frequently attached to sediments, and it is

often through this affiliation that toxic

materials are delivered to the estuary.

Attached to sediments, they make their way to

the benthic zone, where they accumulate

within organisms and become introduced to

the food web. Under certain environmental

conditions, toxins may also be released from

sediments into the water column. 

Other areas suffer from large quantities of

marine debris. Storm sewers, combined sewer

overflows, and carelessly dropped litter are

among the sources of these eyesores. Marine

debris found on estuarine shorelines and

underwater pose a health hazard to marine

animals and humans. 

Whether the problems are unique to one

estuary or common to many, several have

worsened over recent decades. Simultaneously, however, the interest of a few

concerned citizens has grown into a nationwide awareness that the environment is a

necessary national priority. 

Along with this growing recognition, the

means to assess the health and status of our

nation’s waters has also evolved. While

scientists provided many early clues to the

deterioration of estuarine water quality,

citizens have become important contributors

in the long-term effort to identify and address

water quality problems. ■

Agricultural

Runoff

Wastewater

Treatment

Plant

Animal/Pet

Waste

Ground Water

Golf

Courses

Marinas

Urban Runoff

Industrial

Facilities

Septic

Systems

Waste

Facilities

Air Deposition

Forestry

Lawn Fertilizing

Dredging

Recreational

Activities

Figure 2-3. Potential sources of estuarine pollution. 
2-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

Clarifying and characterizing the problems

unique to an estuary help clear the path toward

potential solutions. The first step in solving

each problem is defining it. One should ask:

• Is there a problem? 

• If so, how serious is it? 

• Does the problem affect only a portion

of the estuary, or the entire body of

water? 

• Does the problem occur sporadically,

seasonally, or year-round? 

• Is the problem a naturally occurring

phenomenon, or is it caused by human

activities? 

The Importance of Monitoring

A systematic and well-planned monitoring

program can identify water quality problems

and help answer the questions critical to their

solutions. Useful monitoring data will

accurately portray the current chemical,

physical, and biological status of the estuary.

This type of information, collected

systematically over time, can establish a

record of water quality conditions in an

estuary. 

If reliable historical data exist for

comparison, current monitoring data can also

document changes in the estuary from the past

to the present. These data may serve as a

Examples of Water Quality Degradation

• The Petaluma River, a tributary to San Francisco Bay, has experienced seasonal algal blooms, low oxygen

levels, and fish kills resulting from municipal waste discharges.

• Low dissolved oxygen levels are problematic in Corpus Christi Bay and Galveston Bay in Texas and in Mobile

Bay, Alabama. Low oxygen levels are especially prevalent where wastewater discharges and surface runoff go

to areas that are poorly flushed or have little circulation.

• In 1990, nitrogen levels in Sarasota Bay, Florida, were estimated to be three times greater than predevelopment

levels.

• Pollution from surface runoff has been implicated in nearly 30 percent reduction in seagrass coverage that

occurred in the Indian River Lagoon, Florida, between 1970 and 1990. If no action is taken, it is estimated that

pollution from surface runoff will increase by more than 30 percent by the year 2010 due to increasing human

population.

• Runoff from the land contributes more than 50 percent of nitrogen loadings to Maryland’s coastal bays, with 50

percent of these loadings coming from agricultural feeding operations (primarily poultry), which make up less

than one percent of the watershed.

• A citizen-based water quality sampling effort in Buzzards Bay, Massachusetts, reports that nine of the Bay’s 30

embayments experience poor water quality (primarily from nutrient over-enrichment) during the summer

months. Another eight embayments are in transition from good to poor water quality. At least 50 percent of all

the embayments have shown a slight to moderate decline in water quality during four years of monitoring.

• From mid-July through September each year, up to half of Long Island Sound in New York experiences

dissolved oxygen levels insufficient to support healthy populations of marine life. Nitrogen loads are estimated

to be more than twice those of pre-colonial times with 57 percent of the nitrogen entering the Sound each year

attributable to human activities.

(Source: ANEP, 1998.)

The Solutions
2-9

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

warning flag, alerting managers to the

development of a water quality problem. Or, on

the positive side, data comparisons may indicate

improvements in estuarine water quality. 

Thus, monitoring programs can perform a

variety of functions. The most effective

monitoring program, however, resolves the use

of the data early on so that the program design

best addresses the defined problems. Most

citizen monitoring programs serve to: 

• supplement federal, state, and local

monitoring efforts; 

• educate the public; 

• obtain data from remote areas; 

• obtain data during storms or other unique

events; 

• bring a problem area to light; and/or 

• document the illegal discharge of waste. 

Citizen monitoring data, collected accurately

and systematically, can be an important

supplement to data collected by professionals.

Accurate data often have far-reaching uses that

the organizers may not have anticipated at the

outset of their program. Indeed, these data have

the potential to influence management actions

taken to protect the waterbody. Further uses of

the data include: 

• providing a scientific basis for specific

management decisions and strategies; 

• contributing to the broad base of

scientific information on estuary

functions and the effects of estuary

pollution; 

• determining multiyear water quality

trends; 

• documenting the effect of nonpoint and

point source pollutants on water quality; 

• indicating to government officials that

citizens care about their local waterways; 

• documenting the impacts of pollution

control measures; and 

• providing data needed to determine

permit compliance. 

Assessing water quality should not be conducted purely for the sake of monitoring itself.

Ultimately, the protection and restoration of an

estuary’s wildlife, natural functions, and compatible human uses is of greatest concern. To restore

an estuary, we must ensure that water quality

conditions remain within the optimal range for

the health and vitality of native species. As scientists discover the ideal habitat conditions for each

species, monitoring data will be instrumental in

judging how often conditions are suitable for the

survival and propagation of these species. 

Measures of Environmental Health 

and Degradation

Estuaries are complex systems with a large

assortment of habitats, animal and plant

species, and physical and chemical conditions.

As a result, there are dozens—perhaps

hundreds—of monitoring parameters being

used to evaluate the health of estuaries.

Several parameters describe the basic

chemical, physical, and biological properties

of an estuary. These traits determine the

estuary’s fundamental nature. They form, in

essence, the ABCs of estuarine water quality

and set the stage for selecting the

environmental parameters that will indicate

estuarine health.

Warning: It’s All Connected!

Simply measuring a chemical concentration or locating a particular

organism does not necessarily tell the full story of an estuary’s health.

Several factors may interact to influence your data.

To facilitate discussion of different monitoring parameters, this

Methods Manual addresses monitoring topics according to chemical,

physical, or biological properties. However, it is important to

recognize that one environmental parameter may influence another

(Figure 2-4). Temperature, for example, largely governs the rate of

chemical reaction and biological activity. The pH affects the solubility

of certain chemicals in the water. Nutrient concentrations influence

algal growth, which ultimately affects dissolved oxygen

concentrations. Turbidity controls the amount of sunlight that can

reach underwater plants. 

Chapter 7 describes several environmental factors that could

influence your monitoring results. 
2-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

Chemical Measures

Chemical parameters are the main focus of

many volunteer estuary monitoring programs,

which concentrate on pollutants that arrive in

the estuary from point and nonpoint sources

(e.g., nutrients, toxins). Other chemical

measurements serve as indicators of problems.

Low dissolved oxygen concentrations, for

example, can be disastrous for many estuarine

organisms. 

Unit 1 highlights some of the common

estuarine chemical monitoring parameters and

techniques.

Physical Measures

Some parameters are neither biological nor

chemical in nature; they represent measures of

the physical environment. Sediment and

marine debris are examples of natural and

manmade materials, respectively, that can

affect estuarine organisms’ living environment

and health. 

Unit 2 discusses some measures of the

physical environment employed by many

volunteer estuary monitoring programs.

Biological Measures

Living organisms can reveal a great deal

about an estuary’s health. In some cases, their

presence can be a good sign. For example, the

widespread distribution of submerged aquatic

vegetation (SAV) can suggest that turbidity or

excessive nutrients may not be problems in

the area. Other organisms, however, can be

causes of concern. High bacteria levels can

indicate the presence of pathogens in the

water—a potential human health risk. The

presence of non-indigenous species can

threaten native organisms and disrupt a

delicate ecological balance.

Biological monitoring is discussed in

greater detail in Unit 3.

Peculiarities of Volunteer Estuary

Monitoring

You may be thinking, “I know how to

monitor streams, so I know how to monitor

estuaries.” In many respects, you are correct.

Basic monitoring techniques are similar for

streams, lakes, rivers, and estuaries. However,

estuaries have several, often unique,

N+T

Atmosphere Fresh-saltwater transition

(maximum turbidity zone)

Point sources

sewage treatment

plants (N + T)

Nonpoint sources

farm & urban runoff,

groundwater (S + N + T)

Plankton

Die off Filter

feeders

Sediment (S)

Nutrients (N)

Toxic pollutants (T)

Sediment sink

Sediment

absorption & transport

Suspended

S + N + T

Dissolved

N + T

Lighter freshwater

Heavier seawater

Resuspension

Settling

Release

Uptake

Man

N + T in food chain

Figure 2-4. Schematic diagram of physical, chemical, and biological processes interacting in estuaries (redrawn

from USEPA, 1987).
2-11

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

properties that must be considered when

conducting monitoring efforts. As one

volunteer leader wrote, “Estuary monitoring

can be characterized as a mixture of river and

lake monitoring techniques—liberally salted”

(Green, 1998).

Two main influences that make estuary

monitoring unique are tides and salinity.

Volunteers are strongly recommended to learn

proper techniques for monitoring in an

estuarine environment.

Tides 

Estuaries differ from streams and lakes in

several respects. First and foremost, they are

subject to tides and the accompanying mixing

of salt and fresh water. Any successful estuary

monitoring program must take into account

the tidal stage when scheduling training

sessions and sampling times. Tidal stages can

mean the difference between using a boat 

and trudging across mudflats to get to a

sampling spot. 

The fact that high tide occurs at different

times in different parts of the estuary

undeniably complicates scheduling. Some

monitoring groups schedule sample collection

for low and high tides at each station on each

monitoring date—which translates into

different sampling times for each location! 

Estuaries are complex, with a wide variety

of environments that are constantly changing.

When the tide is rising, incoming salt water

does not mix uniformly with fresh water.

Fresh water is lighter (less dense) than salt

water and tends to stay nearer the surface. The

result is layering, or stratification, which

may necessitate sampling at several depths—

particularly for dissolved oxygen, nutrients,

plankton, and salinity. On the other hand,

tides of sufficient magnitude are effective

mixers of estuarine waters and may break

down stratification.

Tide charts are readily available and should

be a standard part of any program

coordinator’s tool kit. Programs studying

highly stratified estuaries or estuaries with

tidal ranges over a few feet may want to

measure tidal stage. Even if tidal stage data

are not included at the beginning of the

sampling effort, the National Oceanic and

Atmospheric Administration (NOAA)

publishes tide tables for most of the U.S.

This information can be obtained and

applied after the fact, if the monitoring

station is reasonably close to one of the

published tide table sites. 

Salinity

Salinity, the concentration of salts in

water, isn’t usually monitored in streams,

rivers, or lakes, unless there is a connection

with salt water or concerns about excessive

winter season road salting. Salinity changes

with the tides and the amount of fresh water

flowing into the estuary. It is often the major

determinant of what lives where. 

Salinity is often a factor in monitoring many

key water quality variables. For example:

• To properly calibrate most dissolved

oxygen meters, knowledge of salinity

concentration is necessary.

• If you are interested in converting the

dissolved oxygen concentration to

percent saturation (the amount of

oxygen in the water compared to the

maximum it could hold at that

temperature), you must take salinity into

account. As salinity increases, the

amount of oxygen that the water can

hold decreases.

• If you use a meter to measure pH, the

techniques are the same whether you are

testing salt or fresh water. However, if

you use a colorimeter, you must use a

correction factor (available from the

manufacturer) to compensate for the

effects of salinity.

• Although macroinvertebrates (e.g.,

insects, worms, shellfish, and other

animals that lack a spinal column) live

in estuaries, using them as indicators of

ecosystem health is more problematic

than in streams. Estuaries support

Barnegat Bay in New Jersey

(photo by S. Schultz).
2-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

different invertebrate

communities than freshwater

systems, and many of the

key freshwater indicators are

not present in estuaries. In

addition, collection is more

difficult, given the tidal

fluctuations and the muddy

bottom. Finally, data

analysis tools for relating

macroinvertebrate

communities to ecosystem

health have not been as well developed

for estuaries as for streams. 

The Human Element

As mentioned previously, a number of

estuary health problems can be traced to human

activities. Humans also hold the key to finding

their solutions. Many organizations and

individuals are working to restore and protect

estuaries, and volunteer monitoring is one

essential aspect of the effort.

Each player has a different role in volunteer

monitoring efforts, but all must work together to

ensure efficient use of time, resources, and data.

The Role of Government Organizations

On the federal, state, and local levels, a

myriad of government agencies are involved in

volunteer estuary monitoring. Each government

level has a different degree of involvement,

summarized below:

• Federal

Several federal agencies and programs are

involved to some degree in volunteer estuary

monitoring. The U.S. Environmental

Protection Agency (EPA), for example, has

supported volunteer monitoring since 1987.

The EPA has sponsored national symposia on

volunteer monitoring, publishes a newsletter

for volunteers, developed guidance manuals

and a directory of volunteer organizations,

and provides technical support to the

volunteer programs (see Appendix B for

resources).

The EPA also administers the National Estuary

Program (NEP). Unlike traditional regulatory

approaches to environmental protection, the

NEP targets a broad range of issues and

engages local communities in the process. 

The NEP encourages local communities to

responsibly manage their estuaries. Each NEP

is made up of representatives from federal,

state, and local government agencies, as well

as members of the community—citizens,

business leaders, educators, and researchers.

These stakeholders work together to identify

problems in the estuary, develop specific

actions to address those problems, and create

and implement a formal management plan to

restore and protect the estuary. 

To help in their tasks, NEPs work with

volunteer groups and federal, state, and local

agencies to gather critical data about their

estuary. Many NEPs host informational

workshops for volunteer monitors.

Another federal program interested in

volunteer data is the National Estuarine

Research Reserve System (NERRS), which

is administered by the National Oceanic and

Atmospheric Administration (NOAA).

NERRS sites monitor the effects of natural

and human activities on estuaries to help

identify methods to manage and protect

coastal areas. Volunteer groups are often

engaged to help collect valuable data about

estuarine health.

• State

Depending on the state, several agencies may

be involved with volunteer estuary

monitoring. Agencies responsible for water

quality, coastal and/or environmental

management, fish and wildlife, public health,

and other areas have shown interest in

supplementing the data they regularly collect

with information gathered by volunteers. 

State agencies play a major role in volunteer

efforts. Many offer training opportunities,

provide sampling equipment, and compile

and distribute volunteer data. Occasionally,

state laboratories may offer their services to

process samples.

Various land uses, including agricultural,

residential/urban, forestry, mining, and

marinas, can be sources of estuarine pollution 

(photo by Weeks Bay Watershed Project).
2-13

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

Some states are reluctant to fully use volunteer data, which can be a sore point with volunteer groups. To remedy such conflicts,

many states establish quality assurance/quality control (QA/QC) requirements (see

Chapter 5) to ensure that volunteer data can

be used. They may also train volunteer

groups on setting up a quality assurance project plan (QAPP). States can also work with

volunteer groups to identify data needs, key

sampling sites, and formats for submitting

data. Such cooperation maximizes monitoring efficiency and data usefulness.

• Local

Local agencies can get involved with volunteer monitoring in a number of ways. When

considering development plans, they can use

volunteer data to assess baseline water quality

conditions and follow estuarine health as the

development proceeds. Data can also be used

to identify especially sensitive areas, which

can then be designated for special protection. 

Volunteer data can also be helpful for locating local pollutant sources. For example,

local governments are primarily responsible

for septic system permitting, inspections,

maintenance, and enforcement. Particularly

in rural areas where septic systems are common, local agencies may not have enough

staff to sample for bacteria and other indicators of failing systems. By working with volunteer groups, local agencies are tapping into

a valuable resource.

The Role of Non-Government Organizations

With few exceptions, non-government organizations do the bulk of hands-on volunteer

monitoring program planning and implementation. Such organizations can include environmental, school, community, and civic groups.

Their membership is comprised largely of local

citizens.

A major responsibility of non-government

groups is to work with government agencies

and other non-government organizations.

Collaboration is important to coordinate monitoring activities and identify priority areas in

the estuary. By coordinating with other organizations, volunteer monitors can also improve

the likelihood that groups other than their own

will utilize their data. For example, by working

together with state agencies to develop a QAPP

and determine which data the agencies are most

interested in, volunteer organizations can

become a valuable partner in estuary monitoring efforts.

Of course, the volunteer organization may

elect to gather other data that may not be high

on government agencies’ priority lists. This

information still has value! It can be used to

guide local management decisions, educate the

public, establish a baseline, and serve as an early

warning of potential water quality problems. 

Besides working with government agencies,

non-government organizations do grassroots

work. Among other things, they:

• recruit, train, and motivate volunteers;

• supervise monitoring activities;

• procure monitoring equipment;

• raise funds to support monitoring efforts; and

• work with local media to inform the public

of their activities and findings.

The Role of Individuals

It may seem obvious, but should nonetheless

be stated: Without individual volunteers who

commit their time and energy to the effort,

there would be no volunteer monitoring 

programs. 

Besides actually monitoring the estuary, volunteers are valuable resources for other reasons.

They generally monitor close to their homes

and are familiar with the area. Because of their

knowledge of local land uses, environmental

issues, and history of the monitoring area, volunteers can provide valuable anecdotal information that can help explain data. 

Individual volunteers can also assist 

with other non-monitoring activities, such 

as fundraising, writing press releases, 

educating the public, and helping with administrative work.

Chapter 4 goes into greater detail about the

role of volunteers in monitoring programs. ■

A volunteer takes a

Secchi disk reading

from Puget Sound

(photo by E. Ely).
Portions of this chapter were excerpted and adapted from:

Green, L. 1998. “Let Us Go Down to the Sea—How Monitoring Changes from River to Estuary.”

The Volunteer Monitor 10(2): 1-3.

National Estuarine Research Reserve System (NERRS) 

Web site: http://inlet.geol.sc.edu/ nerrsintro.html

National Estuary Program (NEP) Web site: http://www.epa.gov/owow/estuaries/about1.htm

Other references:

Association of National Estuary Programs (ANEP). 1998. Preserving Our Heritage, Securing Our

Future: A Report to the Citizens of the Nation. Washington, DC. 49 pp.

Levinton, J. S. 1982. Marine Ecology. Prentice-Hall, Englewood Cliffs, NJ. 526 pp. 

Maine Department of Environmental Protection (DEP). 1996. A Citizen’s Guide to Coastal

Watershed Surveys. 78 pp.

National Oceanic and Atmospheric Administration (NOAA). 1990. Estuaries of the United States:

Vital Statistics of a Natural Resource Base. U.S. Department of Commerce, National Ocean

Service. 

National Safety Council’s Environmental Center. 1998. Coastal Challenges: A Guide to Coastal and

Marine Issues. Prepared in conjunction with Coastal America. 

Web site: http://www.nsc.org/ehc/guidebooks/coasttoc.htm

Pritchard, D. W. 1967. “What Is an Estuary: A Physical Viewpoint.” In: Estuaries. G. H. Lauff (ed.).

American Association for the Advancement of Science. Publication No. 83. Washington, DC. 757

pp. 

Stancioff, E. 1994. “Changing Tides: Special Challenges of Estuary Monitoring.” The Volunteer

Monitor 6(2).

U.S. Environmental Protection Agency (USEPA). 1987. The State of the Chesapeake Bay, Second

Annual Monitoring Report. Chesapeake Bay Program, Annapolis, MD.

U.S. Environmental Protection Agency (USEPA). 1993. Guidance Specifying Management

Measures for Sources of Nonpoint Pollution in Coastal Waters. EPA 840-B-92-002. January.

Office of Water, Washington, DC.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A Methods

Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

Web site:

Restore America’s Estuaries: http://www.estuaries.org/estuarywhat.html

2-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 2: Understanding Our Troubled Estuaries

References and Further Reading
Planning and Maintaining a Volunteer Chapter 3 Estuary Monitoring Program

Establishing goals, objectives, timelines, and strategies are important steps in

creating an estuary monitoring program. People starting a monitoring program must

also face questions about liability and other risk management issues. Another

important component to a successful program is ongoing financial support. Finally,

the program should be promoted regularly throughout the community. 
Photos (l to r): G. Carver, K. Register, PhotoDisc, K. Register
3-1

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program 

Volunteer data contributes in many important ways to our understanding of the

magnitude and extent of estuarine impairment. Therefore, it is important to ensure

that a volunteer monitoring program is effectively and efficiently designed.

Planning, implementing, and maintaining a volunteer monitoring program requires

organization, time, resources, and dedication. However, the payoffs can be great.

A well-organized, properly maintained volunteer monitoring program can yield

credible water quality data that will enhance capabilities to identify problems,

assess trends, and find solutions to water quality problems. The basic ingredients

for success are outlined in this chapter. 

Establishing goals, objectives, timelines, and strategies are important steps in

creating an estuary monitoring program. People starting a monitoring program

must also face questions about liability and other risk management issues. Another

important component to a successful program is ongoing financial support.

Finally, the program should be promoted regularly throughout the community. All

of these topics are reviewed in this chapter.

Overview
3-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program

Benefits of Partnering

Partnering with data users when planning a monitoring project has several benefits. Examples are

provided below:

• Their input on sampling parameters and methodologies will improve the likelihood that they

will accept and use your data. 

• The participation of regulatory agencies in the process will better ensure that they will be

responsive to potential problems identified by the data. 

• They can guide data management practices to maximize their access to the data (e.g., using

compatible databases, reporting methods, etc.).

• They can help interpret the data.

No step is more critical in the planning

process than establishing the goal or goals of

your estuary monitoring program. Every phase

that follows will depend upon this initial decision. These all-important goals are best determined by the people who will be using the volunteer data. Once the program is established,

volunteers can also help shape future goals. So,

the first step is to identify the people and organizations that will use your data.

Identifying Data Uses and Users 

The best-designed volunteer monitoring programs always begin with a clear understanding

of how the data will be used (see Chapter 5 for

more information). Potential data users should

be identified and asked to serve on the project’s

planning committee. This committee will develop and articulate a clear purpose for the use of

the data. The committee should include members of the scientific research community, local

and regional officials who will play a part in

resource policymaking, representatives of other

monitoring groups, and citizen leaders who are

potential volunteer monitors or who represent

groups from which volunteers will be recruited. 

Determining Goals and Planning 

for Quality

In addition to understanding who will use the

volunteer data, the broad overall goals for the

program should be determined. Is the primary

goal to collect data that will supplement government monitoring? Or is the main goal of the

program to educate the public? For a list of

common program goals, see page 3-5. 

Determining the goals of the program goes

hand-in-hand with creating a plan that can

deliver the level of data needed. As you will see

in Chapter 5, many of these early decisions will

play a critical role in developing a quality

assurance project plan (QAPP). This plan contains details on all the methods you expect your

volunteers to use. Careful planning ensures that

your data will be consistent and of the desired

level of quality. 

The perception that amateurs cannot collect

good quality data is the most common reason

professional water quality managers decline to

take advantage of volunteers as a resource.

However, by preparing a QAPP and adhering to

its elements, your volunteers will produce “data

of known quality” that meet the stated data

quality objectives of your program.

After establishing primary goals, the planning committee should go on to answer, in

detail, the following questions: 

• What are the major problems and 

priorities in the specific estuary or sampling area?

Planning an effective monitoring project

Establishing Goals and Objectives
3-3

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program 

requires that you learn everything you can

about potential monitoring sites by contacting

programs and agencies that might already

monitor in your area. As you identify the most

critical problems of the estuary, include the

perceptions and values of community leaders,

residents, and community organizations.

Selection of priorities will help you determine

what water quality parameters you need to

monitor. 

• What sampling parameters or conditions

will you monitor to characterize the status

of the estuary? What methods or protocols

will you use for collecting and analyzing

samples? How will you pick your sampling

sites, and how will you identify them over

time?

An important part of developing a

monitoring program is selecting monitoring

sites, parameters to be monitored, and a

monitoring schedule. Also, there are

sometimes several different methods or

protocols that can be used to monitor each

parameter. Considerations on selecting the

“what, how, where, and when” to monitor can

be found in Chapter 6.

• How large a monitoring program should be

attempted? 

What is the capacity of the planning committee to raise funds and organize a program?

Do you have the skills, staff time, financial

resources, and community support needed to

reach your program’s goals? If not, the planning committee may need to improve its organizational capacity by creating or strengthening

relationships with community leaders, environmental interest groups, and community agencies

such as local conservation districts and colleges. 

Alternatively, your organization may need to

revisit its goals to set something more realistic.

Always keep in mind that small programs done

well are far better than larger efforts done poorly. Small programs that are well-run can grow

over time.

Prospective Users of Volunteer Data:

• state environmental protection or management agencies 

• state conservation and recreation agencies

• state and local health departments

• water quality analysts

• land use planners

• fisheries biologists

• environmental engineers

• educational institutions, including elementary, middle, and high schools 

• state, regional, and local park staff

• local government planning and zoning agencies

• university researchers

• environmental groups

• soil and water conservation districts 

• U.S. Geological Survey

• U.S. Fish and Wildlife Service

• U.S. Environmental Protection Agency

• National Oceanic and Atmospheric Administration

• Soil Conservation Service
3-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program

• How will volunteers be recruited and trained,

and how often will they receive refresher

courses?

As you develop your new estuary monitoring

program, you will need to determine who will

recruit and train the volunteers. The initial training of the volunteers is a crucial part of developing a water quality monitoring program.

Without such training, usable, high-quality data

cannot be obtained, and volunteers will soon

grow frustrated. In addition to initial training,

refresher courses for volunteers should be

planned. Some practical considerations on successfully recruiting, training, and retaining volunteers can be found in Chapter 4.

• How will you manage your data and 

ensure that your data are credible? 

How will the results of the program 

be presented?

Understanding how the data will be used will

lead you to answers about how the data will be

managed and how reports will be generated to

best fit users’ needs. Choosing a data management approach early on in program development is critical if the hard work of the volunteers is to be meaningful. To take information

from data sheets and convert it to something

that makes sense to your audience requires several elements, which are summarized in

Chapter 8.

Not only is it important to manage and present data according to users’ needs, but every

volunteer monitoring group should also address

early in the planning process how the data

analysis will be communicated back to the volunteers, who should see the tangible benefits of

their work. This requires planning, since the

data may need to be summarized and some

general conclusions prepared for a non-technical audience. Chapter 5 provides more information on this topic.

• How should the program be evaluated? What

outcomes will you measure to determine if

your program is“successful”?

Success, especially at the beginning of a project, can be measured in many ways. The first

time your volunteers take to the field and collect samples can rightfully be considered a success. Proving that it can be done is an extremely important step. Later, success may be measured by whether your data is used in local land

use decisions or leads to actions that improve

the health of the estuary.

Ongoing evaluation of the program is critical.

The planning committee should meet periodically to evaluate the program, update objectives, and refine the monitoring process. You

may decide to improve on sampling techniques,

site selection, lab procedures, or any of the

other elements of your monitoring project

design. These periodic reviews should help

ensure that the volunteer monitoring program

will continue to produce high quality and useful

data for those who require information concerning the estuary. 

Be sure to document the important contributions of the monitoring group to community

leaders, legislative bodies, and the community.

This may help establish program credibility

with funders and aid volunteer recruitment

efforts. ■
3-5

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program 

Common Goals of Citizen Monitoring Programs:

• To supplement water quality data collected by professional staff in water quality agencies and scientific institutions.

• To educate the public about water quality issues. 

• To build a constituency of citizens to practice sound water quality management at a local level and build public

support of water quality protection. 

• To obtain data from remote areas during storms or during unique events in the watershed.

• To increase awareness about a problem in the estuary, such as the documentation of illegal discharges into the water.

• To establish baseline conditions where no prior information exists.

• To determine water quality changes through time.

• To identify current and emerging problems, such as pollution sources, habitat loss, or the presence of nonindigenous species.

Designing a Data Collection Form

Most monitoring data, including those collected by volunteer programs, are stored and managed by computer. Data users

and the database manager should be involved in the development of the data collection form to be sure that it clearly

identifies the information to be collected and that the information can be easily and accurately entered into the database.

Consideration should also be given to the ease with which the form can be filled out and understood by the volunteers.

Several suggestions for consideration when developing a data collection form are as follows:

• Print the form on waterproof paper, if possible.

• Keep it simple for volunteers to fill out.

• If many of your volunteers are over 40 years of age, consider using larger type sizes (12 point and larger).

• If possible, keep your data form to one side of an 8 1/2” x 11” piece of paper so that it can fit on a clipboard.

• Ask your volunteers for input on how the form can be improved.

• Remind volunteers that pencils are best when filling out the forms.

• Always include the full address and contact phone numbers of your program.

• On the back of the form, include:

– emergency phone number and notes about safety;

– a chart showing the expected ranges for each parameter that is tested (this can help volunteers verify that they are using

the monitoring equipment correctly or determine whether their chemicals need to be examined for accuracy);

– steps to remember for collecting the sample or data; and

– an identification key of organisms (e.g., phytoplankton, SAV or macroinvertebrates). 

• Specify on the form what units should be reported with the data. For example, if Secchi depth is measured in

centimeters, then put “cm” on the line where volunteers write their Secchi depth data.

• Include on the data form any equations needed to convert measurements. This will minimize the chance of error.

• Put a reminder that a value of zero should not be reported. Remind volunteers to report the value as less than the

lowest value that can be read with the equipment (Miller, 1995). For example, if the range of a test is 0-1 mg/l, the

smallest increment is 0.01 mg/l, and the test result is zero, report the value as “less than 0.01 mg/l” or “<0.01 mg/l.”

Appendix A contains several examples of data forms.
3-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program

Questions of insurance, safety, and liability

are always important considerations when

starting any program that will place

volunteers in the field. Insurance issues are

rarely the favorite topic of volunteer

monitoring programs. In fact, many programs

may not be fully aware of what their

insurance policies cover. Some may not even

have liability insurance.

If people are confused about issues of

insurance, safety, and liability (collectively

termed risk management), there is good

reason; this whole field is a tangle. To make

matters worse, laws differ dramatically from

state to state. For example, the interpretation

and validity of waivers depends to a large

degree on what state you are in. Workers’

compensation is another case in point: some

states allow volunteers to be covered while

others do not. 

So, what is a volunteer monitoring

organization to do? The following sections

offer answers to some of the most common

questions. This is basic information; volunteer

groups are encouraged to seek legal advice

regarding any risk management issues.

Liability Insurance 

Liability insurance protects you if you are

sued. The most common type is “general

liability,” which covers most bodily injury

and property damage claims. A liability policy

covering an organization does not necessarily

cover its volunteers in case they are sued

personally. You can get your organization’s

liability coverage extended to your volunteers,

but beware: once volunteers are added to the

list of insured, they are excluded from

collecting medical benefits under the policy if

they are injured. A general liability contract

protects the organization against claims

brought by a third party, and once a volunteer

is listed as an “insured” he or she is no longer

a third party. In other words, you cannot sue

yourself for damages. 

Individual volunteers can also get liability

coverage under their own homeowners’

policies. It is especially important for each of

your organization’s board of directors to do

this, since by law they can be held personally

liable for damages caused by the organization.

Note, however, that most homeowners’

policies do not provide protection if someone

sues you for a purely financial loss. 

Injuries to Volunteers 

How can you protect your volunteers in

case they are injured “on the job”? In some

states, volunteers can be covered by workers’

compensation; call your state Department of

Employment for information about applicable

laws and the cost of covering volunteers. If

workers’ compensation is unavailable or very

expensive, your organization may want to buy

a separate accident and injury policy for

volunteers. For a “supplemental” policy (one

that takes effect only after the individual’s

own medical coverage is exhausted), the cost

is usually only a few dollars per year per

volunteer. Another option is to include

volunteers in the medical payments portion of

your general liability policy; however, the

dollar amount of medical coverage in such

policies is usually fairly limited. 

Insurance Through Partnering 

Teaming up with a partner who has good

coverage is popular among volunteer

monitoring groups. In some cases, volunteers

sign a partner’s form, after which they are

covered by workers’ compensation. This is

easier and less expensive to do in some states. 

For programs associated with a university,

participants may be considered university

volunteers and covered by the university’s

insurance policy. Student monitors may also

be organized under a larger umbrella

organization that affords coverage. The Boy

Scouts of America, for example, has a

division known as Explorer Posts, which

allow boys and girls to participate. Each Post

Insurance, Safety, and Liability—Risk Management 
3-7

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program 

focuses on a specific activity (in this case, the

water monitoring project). The group must

abide by all Explorer Post regulations, and

participants are eligible for low-cost insurance

coverage through the Boy Scouts. 

Waivers 

A carefully worded waiver can protect you if

you are sued for negligent (unintentional) acts.

Waivers are best suited for adults; those signed

by minors (persons under 18) usually do not

hold up in court. 

It is important to make sure your waiver

clearly spells out all the risks involved in an

activity. Because states interpret waivers differently, it is impossible to design a standard form

that can be used in all jurisdictions. Consult a

lawyer for the best wording to use in your state. 

Risk Reduction 

Prevention, as always, is the best medicine.

Volunteers should be trained to look for and

avoid hazards at sampling sites, to use the

buddy system, and to take appropriate precautions when handling chemical reagents. Above

all, monitoring groups should stress that volunteer safety is always more important than the

data and that volunteers should never put themselves at risk to obtain a measurement. See

Chapter 7 for a discussion of volunteer safety.

Equipment Insurance

Volunteer groups may also wish to consider

insuring their monitoring equipment for damage.

This is especially true for expensive gear. ■

Paying for the Program—The Financial Side

Volunteer monitoring is cost-effective, but

not free. Depending on the equipment and

monitoring methods you choose, outfitting a

team of monitors can cost several hundreds or

thousands of dollars. Paying a salary (either

part- or full-time) to one or more volunteer

coordinators is also a critical component to

many water quality monitoring programs.

Dedicated staff members are needed to ensure

program continuity, train volunteers, manage

data, and ensure that data quality goals are

being met. The following sections offer

guidelines for finding the funds that will help

your program to grow and flourish.

Funding Sources

Fundraising is an important component of

running a successful volunteer monitoring

program. Without funding to cover program

costs, a program simply could not exist. The

principal sources of funding for volunteer

monitoring programs are government funds

and private contributions. 

Government Funds and Support

Federal grants are sometimes available to

public or nonprofit non-governmental

organizations to initiate and maintain citizen

monitoring programs. Usually, these funds are

distributed through grants given by the state.

National Estuary Programs are eligible for

combined federal and state funds to support

research and public participation projects that

can include volunteer monitoring. Some

federal funding for volunteer monitoring

programs is also routed to state universities

from the National Oceanic and Atmospheric

Administration (NOAA) Sea Grant Program

and the Coastal Zone Management Program. 

State and local funding sources may also

exist to implement and maintain volunteer

monitoring programs. Some state funding is

distributed only to state agencies, while other

programs provide funding to private organizations. Call your state and local agencies that

are responsible for water quality, coastal,

and/or environmental management to learn
3-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program

about resources and support they offer to volunteer monitoring programs. 

States vary in the amount of support they

offer to volunteer monitoring programs. For

example, in Oregon, interested citizens are

trained in water quality monitoring techniques

by the Oregon Department of Environmental

Quality and supplied with all necessary equipment. Alabama has an extensive statewide monitoring effort that offers training, equipment,

and quality assurance procedures through

Alabama Water Watch, which is supported by

state and federal funds. Other states may not

provide equipment, but offer valuable assistance in developing quality assurance project

plans and in selecting monitoring sites. 

Private Funds and Support

Private contributions to fund your program

can come from corporate sponsorships, foundation grants, individual contributions, fundraising

events, civic organizations, board members, and

even the program volunteers. 

Foundations

Grants from foundations are very important

for volunteer monitoring programs throughout

the United States, and many resources list

sources of foundation grants. 

A great way to begin your funding search is

by visiting Web sites. One site run by The

Foundation Center (http://fdncenter.org/) compiles information on more than 37,500 active

U.S. private foundations and corporate giving

programs. This resource, and others like it, can

help you identify appropriate funders. Ask your

local library or university if they have directories of foundations that you can review. Be sure

to read the description of each foundation carefully to learn if their funding goals are a good

match for your program. 

Check also to see if your state has a nonprofit

statewide organization devoted to water quality

or environmental issues. Many of these organizations provide research grants and offer funding that is available only within the state.

What’s in a Budget?

Budgets for volunteer water quality monitoring programs include some or all of the

following: 

• staff salaries and fringe benefits;

• equipment and refilling chemical supplies;

• laboratory analysis;

• office overhead (phone, postage, duplicating, etc.);

• data management (software program, data entry, storage and retrieval);

• data analysis (including cost of a statistical software package);

• travel expenses (to train volunteers, perform quality assurance checks, attend local and

regional conferences, and promote the program);

• printing costs for annual reports and newsletters; and

• other expenses (conferences, Web site maintenance, etc.).

(Adapted from USEPA, 1990.)
3-9

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program 

Local Sponsors

To find the initial funding that is needed to

start a volunteer monitoring project, many

groups also seek local supporters to underwrite

postage, printing, and equipment purchases.

The first step in this process is to identify

potential donors through research. Talk to the

leaders of other local nonprofits and ask them

about their supporters. While some nonprofits

may not want to let you know where they get

their funding, others will be willing to give you

helpful sources. Make a list of all the people,

local businesses, and other organizations that

share an interest in the water quality of the estuary. 

Prepare a brief, focused statement outlining

what the volunteer estuary monitoring program

hopes to accomplish. Make appointments to

meet with prospective supporters, and let them

know how their support will benefit the community. Ask for a specific amount of funding.

Corporations have to be convinced that part of

their advertising budget should be spent on

your program, so be sure to let them know how

you will acknowledge their support.

Keep in mind that local sponsors may fund

what is important to them and their employees.

If their employees can and want to participate

in the project, the employer is more likely to

help fund the project.

Special Events

Another fundraising strategy is to plan a special event. In addition to raising funds, this

approach can generate publicity about your volunteer monitoring program, help educate the

citizens in the estuary watershed, and recruit

new volunteers. In fact, many events may focus

less on fundraising than on gathering new supporters. 

Special events can take a great deal of effort

to plan, so be sure this goal is achievable. Some

special event ideas include: a concert on a

beach, a festival or fair, a dinner with a guest

speaker, or an auction of donated items. Local

businesses, newspapers, and radio stations are

important partners to line up early in the planning process. The publicity offered by local

media will help ensure good attendance for

your event (see “Promoting the Program—

Working with the Media” in this chapter for

more information). Also consider “tagging”

your fundraising event onto an established community event. For example, if your community

has an annual festival, your group could plan

one aspect of the festival and keep the proceeds. 

Board Members

In addition to contributing time, professional

knowledge, and expertise, the board members

of some volunteer organizations are also

responsible for giving and getting financial support. If your program decides to have a board

and if fundraising is to be one of the board

responsibilities, prospective board members

need to understand this expectation.

Membership Support

There are pros and cons to having a duespaying membership as part of your monitoring

program. On one hand, the people who live

near the estuary and in its watershed are often

interested in the water quality data that will be

generated; as a result, they may be willing to

help financially support your volunteer monitoring program. But maintaining membership

records will take time and effort on the part of

program staff. All donors must be thanked

promptly, and records must be kept so that

members can be billed when their memberships

have expired. Members will also expect to be

kept informed of program accomplishments,

which might require the development of a

newsletter or Web site.

In-Kind Donations

Many people and companies cannot contribute cash to your program, but would be willing and able to lend their support with in-kind

gifts. In-kind donations of goods and services

can offer tremendous support to a volunteer

monitoring program. A graphic designer can

donate time and expertise to develop a
3-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program

brochure. A local printer or truck company can

donate printing or hauling services. Individual

volunteers can also assist with other non-monitoring activities, such as fundraising, writing

press releases, educating the public, and doing

administrative work.

Other volunteer monitoring programs can be

another source of valuable support. Several

non-government organizations around the U.S.

conduct volunteer estuary monitoring (see Ely

and Hamingson, 1998), and have gained knowledge and skills that they can share with newer

programs. Conversations with these other environmental, school, community, and civic groups

can greatly shorten your learning curve.

Writing a Successful Proposal

When writing a funding proposal, make your

project sound exciting and focus the project

description so that it appeals to the funder.

Written proposals are sometimes the only

opportunity you will have to present your program to funders. It is your chance to show them

that your organization is credible, has a strong

structure, and will be a valuable asset. Funders

need to be convinced that your program will be

successful and worth the investment. They want

to feel as if they will be part of a successful

project that will lead to tangible results.

Make sure that the proposal is professional

and complete, and that it “sells” the importance

of the project. A successful proposal should

contain the following:

• cover letter (brief summary of the project,

amount of funding requested, signature of

top staffer, and contact person’s name and

phone number);

• introduction (description of organization,

mission, population served, why your

organization is best suited to do the project);

• project goal (and how it fits in with your

mission);

• project objectives (specific measurable

steps to meet the goal);

• request (specific dollar amount 

requested); and

• expected results.

When presenting a funding proposal:

• read the foundation’s or grant’s guidelines

carefully and follow them exactly;

• ask for the right amount (know the foundation’s limits);

• be succinct;

• do not misrepresent a “partnership” or

exaggerate any aspect of your goals; and

Fundraising Is About Relationships 

To develop funding, develop relationships. Fundraising is a long-term process; you need to

build a relationship that benefits all involved. Establishing relationships with multiple funders

will help you to ensure that you are not too dependent on one funding source. 

After identifying funding sources, make personal contact with them. Call the contact person at

a funding organization and ask a few questions about how your proposal can be targeted to

the organization’s funding goals. Your best chance to receive funding will be from

organizations whose philanthropic philosophies match your program goals. For example, if

potential funders are mainly interested in education, then highlight the educational aspects of

your water quality monitoring project.

In order to survive as an economic entity, integrate fundraising into everything you do as an

organization. Your program volunteers can also be valuable fundraising assets, as they can

promote the program with others in the community.
3-11

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program 

• highlight the expertise that the program

leaders bring.

It is critical to make your issue relevant and

understandable to funders. Be careful to use

layperson’s terms in your writing, and do not

assume that the person reading your proposal

knows acronyms or technical terms. After you

have written your proposal, ask someone who

is unfamiliar with your program’s goals to read

the proposal. If your reader is unclear about any

aspects of your proposal, your prospective funder will likely be unclear as well; a rewrite is

necessary.

Keep Funders Happy!

No matter what your source of funding, it is

important to keep your supporters happy!

Remember: The same people who make

decisions to support your program need to

feel that their support is appreciated.

Be sure to acknowledge and thank your funders every time they provide any support.

Keep them informed about the progress of

the program and invite them to attend your

receptions, banquets, workshops, training

sessions, or demonstrations. Companies,

foundations, and individuals often hope to

increase their visibility within the community in return for their cash or in-kind donation. You can acknowledge their support by

including their names and/or logos in press

releases, brochures, reports, or even T-shirts

made for the volunteer monitors. Make sure

to get approval from the funders before

using their names or logos; some donors prefer to remain anonymous.

Forming Partnerships

Being part of a partnership with other organizations can help your chances of getting a

grant. Funders like to see that your program is

in a partnership, as this shows that your program is supported by others in the community.

Partnerships also convey that the expertise of

many people will be contributing to the program. Many foundations like regional efforts

and prefer to make larger grants, so partnering

with other groups to make joint applications is

very beneficial.

Some funders require nonprofit tax status

[called 501(c)3 status] from the Internal

Revenue Service. Obtaining this tax status is an

important step for a nonprofit group, but the

process can be lengthy and requires a fee of up

to $500. If you do not have this tax status, then

maybe you can partner with a group that does

have it.

Partnerships have additional benefits. A volunteer program should look for other groups in

the area doing similar projects in adjacent or

complimentary waterways. Partnering with

these groups could lead to cost savings on supplies (buying in bulk is cheaper than buying in

small volumes) or hiring consultants or staff

(one person could work on several projects).

Your monitoring program can also gain

strength by taking advantage of opportunities

provided by government agencies. Several

agencies are involved in volunteer estuary monitoring on the federal, state, and local levels.

Federal agencies, such as the U.S.

Environmental Protection Agency (EPA), support volunteer monitoring by sponsoring symposia on volunteer monitoring, publishing

newsletters, and developing guidance manuals

(see references at the end of each chapter and in

Appendix B).

Another federal program interested in assisting volunteer monitoring programs is the

National Estuarine Research Reserve System

(NERRS), which is administered by the

National Oceanic and Atmospheric

Administration (NOAA). Also, learn if your

estuary is part of the National Estuary Program

(NEP). This program, administered by the EPA,

targets a broad range of estuary-related issues

and engages local communities in the process.

NEPs work with volunteer groups and federal

and state agencies to gather critical data about

their estuary. Many NEPs host informational

workshops for volunteer monitors and support

volunteer groups in other ways. ■
3-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program

Now that you have clearly established the

primary goal or goals and know the program

priorities, your challenge is to meet your objectives by focusing your resources and mobilizing

the community. Publicizing a volunteer monitoring program through the television, radio, or

newspaper media is an effective, cost-efficient

method to reach citizens in the watershed. The

rewards of successful press coverage can be

high as the public will learn about the estuary

and the efforts of your group.

Working with the media requires logistical

planning. Create a communications strategy

that is an integral part of the monitoring program; make communications a priority and

allow time to prepare press releases and meet

press contacts.

People are interested in reading or hearing

about their local environment—it is a qualityof-life issue to readers. Yet getting the press to

pay attention to a volunteer monitoring program

is sometimes a challenge. Reporters look for the

“big story,” but many of our current environmental woes are accumulative problems from

what we do on a daily basis and have done for

years. Onetime specific events, such as a sewer

overflow, will usually receive coverage and can

be good opportunities to include information

about the bigger problems of water pollution.

Many reporters want to write about community

groups and environmental issues, but their first

and most pressing concerns are breaking news.

Press Releases

To help get the word out about your

program, press releases are priceless! A press

release is a one- or two-page document that

informs newspaper and electronic media

about your program and its goals, findings,

upcoming events, need for volunteers, and

other topics of interest. Writing one press

release and sending it to many local news

outlets is a cost-efficient and effective method

to inform the community about your program. 

As you write a press release, know what

you want to say, whom you want to reach,

and what you want the reader or viewer to

“take away.” Think about why the health of

the estuary is important to the readers or

viewers. 

To increase chances of getting an article in

a newspaper, do your best to write the story

for the reporter. A well-written press release

stands a better chance of getting published

without many modifications, thereby reducing

the likelihood that your message gets

presented incorrectly. You have to anticipate

Promoting the Program—Working with the Media 

Some Funding Challenges

Many funders insist that all grants go toward direct project expenses and will not allow any

money to go to administrative or overhead costs (e.g., rent, phone bills, electricity). This restriction can be a challenge, given that there are administrative overhead costs associated with running any program. There are other terms you can use in your budget instead of “administrative”;

for example, you may use phrases like “contacting volunteers” and “program development

costs” to cover some phone calls, photocopying, etc. Developing a partnership with other likeminded groups can also help defray some of these overhead costs.

Some grants are paid on a reimbursement basis. For new monitoring groups, this necessitates

finding a source of money to pay the bills while waiting for the reimbursements.
3-13

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program 

how the press would present the topic. Frame

the issue the way a journalist would, and

think about what would be their lead. Give to

the press the “who, what, where, when, why,

and how.” Remember: You often have to

educate reporters and inform them why they

should care about your issue. 

Make it easy for reporters to contact you if

they have questions or want to interview you.

At the top of the press release, provide a

contact person for the press to call for more

information. You may also want to include at

the end of the press release a contact name

and number for the public to use (this may be

a different number from the press contact). 

The timing of press releases is important.

Press releases are best sent to newspapers

about two weeks before the event to allow

photographers and writers to be scheduled.

Television stations should receive your press

release one to two weeks prior to the event. It

is best to mail or fax press releases, then call

the reporter to see if he or she has any followup questions. Take time to call reporters and

give them “background” information about

your organization.

When writing a press release, it helps to

have a bold, recognizable masthead on your

stationery. For other professional touches,

contact a local advertising agency to learn if it

would donate the time of its professional staff

to assist you. Also, check with your local

library for books with specific examples of

model press releases.

Press Conferences

A press conference should be

an organized event that has

been well thought out and

delivers specific news. In other

words, press conferences must

have substance. If your

program has discovered an

issue that is of interest to the

community or if findings from

your volunteer monitors have

led to a significant event, hold

a press conference. For good

visuals, invite the press to

cover a real activity (not a

posed shot) and let volunteers

know that they will be

photographed. Also, prepare

good charts or graphics to

show the data you have

collected. Local maps showing water

conditions are also effective. Press

conferences that merely announce upcoming

events are seldom attended by busy reporters,

and if the reporters show up and are

disappointed by the lack of content, they may

not come again to more “worthy” press

conferences.

The timing and location for a press

conference are important. Early in the day is

preferred, as it allows plenty of time for TV

stations to edit the tape before the noon and

evening news broadcasts. Choose a place that

has good visuals, such as a location along a

waterbody that you have been studying or at

your headquarters where volunteers can be

shown working in the background. ■

When working with the media, always be

prepared for an interview. Have your

facts together and use humor, analogies,

and inspiration whenever possible (photo

by PhotoDisc). 
3-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program

• Develop long-term professional and personal relationships with reporters, editors, and

producers at your local news stations and newspapers. Reporters value contacts with

reliable, credible non-government groups like volunteer monitoring programs.

• Write a short fact sheet about your program.

• Create media materials that are clear, concise, and understandable to the general public.

Edit and format materials so that reporters under deadline can read them quickly and

easily.

• Localize. Make the issues into stories that address the local community.

• Use humor, analogies, and inspiration in your interviews.

• Include graphics, charts, and visuals, which draw the attention of reporters.

• Highlight citizen and student involvement.

• People are more interesting than facts, and animals are more interesting than people. Use

animals, protesting citizens, or interested students as a “hook” with the press.

• Write a short summary of your group’s findings (two pages with one visual aid) and send

it out with a press release.

• If a reporter wants information over the phone, ask if you can return the call in five

minutes. Take those five minutes to write down the major points you want to make, then

call the reporter back. This way, you will be focused on the two or three most important

points you want to make in the interview.

• Know reporters’ deadlines. They tend to be busiest in the afternoon trying to meet

deadlines, so call them in the morning.

• Always cover the important details: who, what, when, where, why, and how.

• Give good directions to the event or field site.

• Explain the topic in simple terms. Avoid terms like “nonpoint source pollution”; instead,

show how people and animals will be impacted. 

• Be flexible in scheduling the media. Understand that “late-breaking” stories may require

you to reschedule an interview. 

• Designate spokespeople and have them practice their communication skills.

• Always say the full name of your organization—not an acronym. In fact, avoid using

acronyms altogether, since most people are unfamiliar with them and will not understand

what you are talking about.

• Remember that television stations have broader geographical areas of interest than

newspapers.

• Plan to have interesting visuals, an articulate spokesperson, and video to illustrate a

point. These are required if you want to get television coverage.

Tips for Working Successfully with the Media: 
3-15

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program 

Portions of this chapter were excerpted and adapted from:

Ely, E. 1996. “Are You Covered?” The Volunteer Monitor 8(1).

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A

Methods Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

U.S. Environmental Protection Agency (USEPA). 1990. Volunteer Water Monitoring: A Guide

for State Managers. EPA 440/4-90-010. August. Office of Water, Washington, DC. 78 pp.

Other references:

Chabot, W. 1999. “Volunteer Estuary Monitoring: Media, Outreach, Publicity.” In: Meeting

Notes—U.S. Environmental Protection Agency (USEPA)/Center for Marine Conservation

(CMC) workshop: Volunteer Estuary Monitoring: Wave of the Future. San Pedro, CA:

February 22-24, 1999.

Courtmance, A. 1999. “Fundraising.” In: Meeting Notes—U.S. Environmental Protection

Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary

Monitoring: Wave of the Future. Toms River, NJ: April 14-16, 1999.

Ellett, K. 1993. Introduction to Water Quality Monitoring Using Volunteers. 2nd ed. Alliance for

the Chesapeake Bay. Baltimore, MD. 26 pp. 

Ely, E. and E. Hamingson. 1998. National Directory of Volunteer Environmental Monitoring

Programs. 5th ed. U.S. Environmental Protection Agency, Office of Wetland, Oceans, and

Watersheds. EPA-841-B-98-009. Web site: http://yosemite.epa.gov/water/volmon.nsf.

Finch, B. 1999. “Media, Outreach, Publicity.” In: Meeting Notes—U.S. Environmental

Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer

Estuary Monitoring: Wave of the Future. Mobile, AL: March 17-19, 1999.

Fritz, P. 1999. “Fundraising.” In: Meeting Notes—U.S. Environmental Protection Agency

(USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary Monitoring:

Wave of the Future. Toms River, NJ: April 14-16, 1999.

Hines, M. 1999. “Media, Outreach, Publicity.” In: Meeting Notes—U.S. Environmental

Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer

Estuary Monitoring: Wave of the Future. Astoria, OR: May 19-21, 1999.

Hubbard, M. 1999. “Media, Outreach, Publicity.” In: Meeting Notes—U.S. Environmental

Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer

Estuary Monitoring: Wave of the Future. Astoria, OR: May 19-21, 1999.

Jordan, B. 1999. “Media, Outreach, Publicity.” In: Meeting Notes—U.S. Environmental

Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer

Estuary Monitoring: Wave of the Future. Mobile, AL: March 17-19, 1999.

Larson, J. 1999. “Fundraising.” In: Meeting Notes—U.S. Environmental Protection Agency

(USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary Monitoring:

Wave of the Future. Toms River, NJ: April 14-16, 1999.

References and Further Reading
3-16

Volunteer Estuary Monitoring: A Methods Manual

Chapter 3: Planning and Maintaining a Volunteer Estuary Monitoring Program

Moore, K. 1999. “Media, Outreach, Publicity.” In: Meeting Notes—U.S. Environmental

Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer

Estuary Monitoring: Wave of the Future. Toms River, NJ: April 14-16, 1999.

Rodgers, E. 1999. “Media, Outreach, Publicity.” In: Meeting Notes—U.S. Environmental

Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer

Estuary Monitoring: Wave of the Future. Toms River, NJ: April 14-16, 1999.

Steiner Blore, V. 1999. “Fundraising.” In: Meeting Notes—U.S. Environmental Protection

Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary

Monitoring: Wave of the Future. Astoria, OR: May 19-21, 1999.

Sterling, J. 1999. “Fundraising.” In: Meeting Notes—U.S. Environmental Protection Agency

(USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary Monitoring:

Wave of the Future. San Pedro, CA: February 22-24, 1999.

Tamminen, T. 1999. “Fundraising.” In: Meeting Notes—U.S. Environmental Protection Agency

(USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary Monitoring:

Wave of the Future. San Pedro, CA: February 22-24, 1999.

Thompson, D. 1999. “Fundraising.” In: Meeting Notes—U.S. Environmental Protection Agency

(USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary Monitoring:

Wave of the Future. Astoria, OR: May 19-21, 1999.

U.S. Environmental Protection Agency. (USEPA) 1991. Volunteer Lake Monitoring: A Methods

Manual. EPA 440/4-91-002. Office of Water, Washington, DC. 121 pp.

U.S. Environmental Protection Agency. (USEPA) 1992. Proceedings of Third National Citizens’

Volunteer Water Monitoring Conference. EPA 841-R-92-004. Washington, DC. 183 pp.

Web sites:

Fundraising Information

Catalogue of Federal Domestic Assistance: http://www.gsa.gov/fdac

Environmental Grantmaking Foundations—Resources for Global Sustainability:

http://www.environmentalgrants.com

The Foundation Center: http://www.fdncenter.org/. Phone: 212-620-4230.

Foundations and Grantmakers Directory: http://www.foundations.org/grantmakers.html

GrantsNet: http://www.hhs.gov/grantsnet

River Network: http://www.rivernetwork.org/library/libsou.cfm
Recruiting, Training, and Retaining Chapter 4 Volunteers

Volunteers are the basic ingredient of a successful volunteer monitoring program.

These citizens bring more than just manpower to the monitoring program—they

also bring a passion to understand, protect, and/or restore the estuary. Trained

volunteers can serve an irreplaceable role as community educators as they

conduct their monitoring duties and share their knowledge with others.
Photos (l to r): K. Register, E. Ely, R. Ohrel, The Ocean Conservancy
4-1

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

Not surprisingly, volunteers are the basic ingredient of a successful volunteer

monitoring program. These citizens bring more than just manpower to the

monitoring program—they also bring a passion to understand, protect, and/or

restore the estuary. Trained volunteers can serve an irreplaceable role as

community educators as they conduct their monitoring duties and share their

knowledge with others. 

Although states monitor water quality and other environmental parameters of

estuaries, there are limits to the coverage they can provide. Volunteers can

supplement this work by monitoring in areas where officials are not sampling.

State officials can then use this information to screen for areas of possible

contamination, habitat loss, or other conditions that impact the health of the

estuary. 

This chapter discusses how to recruit, train, and retain top-notch volunteers. 

Overview
4-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

As you recruit volunteers, it is helpful to

understand what motivates people to donate

their time and energy to a volunteer effort.

Citizens may commit not only because of

their conviction in the merits of the cause, but

also because they will personally benefit from

the experience. Many people volunteer for

service reasons; they believe in the cause and

want to help. Others hope for new friendships

and enjoy the social interaction with likeminded individuals. People are also interested

in personal and career growth, and enjoy

meaningful work that gives them new skills

and knowledge. 

In addition to reasons why people initially

volunteer for a project, there are important

reasons why they continue with the program

year after year—recognition, respect, and a

sense of accomplishment. Volunteers must

feel that their efforts are appreciated and

recognized, that the group respects their skills,

and that their work produces results. Keep

these motivational factors in mind as you

create your recruitment materials and as you

develop a plan to recognize the efforts of

long-term volunteers.

Before you recruit volunteers, you must first

know how many the program requires in its

“start-up” phase. For example, if you have

enough monitoring equipment for 10 teams of

volunteers and each team is to be comprised of

2 or 3 people, then your recruitment goal

should be 20 to 30 volunteers. Some programs

start with a small number of people who are

invited personally to serve as volunteer

monitors. Later, as the program grows and

needs more assistance, all interested citizens

can be invited to join the effort. 

A first step in finding volunteers is to

identify all organizations and individuals in

the area who might want to participate in the

project. Likely groups include civic associations, watershed associations, environmental

advocacy groups, and government agencies.

Individuals interested in volunteering might

be waterfront property owners or commercial

and recreational users of the estuary. Retired

citizens and disabled individuals can make

outstanding volunteers. Schools in the

watershed are also potential sources of

volunteers. Speak with teachers at local

elementary, middle, and high schools,

community colleges, and universities.

Strive to recruit volunteers from a wide

range of backgrounds. This diversity helps

establish the credibility of the program,

ensures cooperation within the community,

and provides the bonus of educating a greater

variety of citizens in the community.

Certain types of individuals or groups may

be more suitable than others for your

particular project. If a primary goal of your

monitoring program is education, then

integrating students and youth groups into

your program will help meet that goal.

However, if your goal is year-round data

collection using expensive and precise

equipment, retired citizens may be more

suitable and reliable. Some programs report a

failure to integrate students and youth groups

into long-term monitoring programs because

of the commitment required and the need for

summertime sampling. 

Many towns and cities have volunteer

centers or “hotlines” which serve to connect

potential volunteers with programs. Inquire

with towns located within the monitoring area

to see if such volunteer centers exist. Other

ways to reach potential volunteers are through

your program Web site or sites managed by

local communities. Local newspapers often

will publish a “call for volunteers” as a

community service.

A press release to local newspapers is an

effective method to let the public know of

your need for volunteers. See Chapter 3 for

information on working with the media to

publicize your program and its need for

volunteers. An attractive brochure or flier

describing the overall volunteer monitoring

program can also be an effective recruitment

tool. 

Recruiting Volunteers
4-3

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

Whether you promote by using a press

release, brochure, or other method, be sure to

include information on the objectives of the

program and describe the benefits to the

volunteer and to the estuary. Also explain

what will be expected of recruits. Potential

volunteers will need to know:

• monitoring site locations;

• project duration and length of

commitment required;

• sampling frequency;

• required equipment (e.g., car, boat,

sampling gear, etc.); and

• volunteer qualifications, if any (keep in

mind that setting specific volunteer

qualifications will limit participation in

the program, possibly below an

effective minimum level).

Short slide presentations that describe the

program and show some of the sampling

equipment and techniques can be a very

effective recruitment tool. This will make it

easier for potential volunteers to determine if

they would be interested in volunteering and

if they are capable of carrying out the

activities requested of them. ■

A successful monitoring program requires

well-trained volunteers. Few other aspects of

the program are more important, so adequate

time and money should be budgeted annually.

Without volunteer training, usable, high-quality

data cannot be obtained and volunteers will

soon grow frustrated. Proper training provides

the common ground necessary for a welldesigned and scientifically valid data collection

effort. Your program’s volunteer coordinator

plays an important, key role in the success of

the entire effort.

Training citizen volunteers is time

consuming and demanding. Nevertheless,

successful training sessions are key to a longterm and effective monitoring program. It is

well worth the effort to devote this time to the

volunteers.

Introductory training ensures that all

volunteers learn to collect and analyze

samples in a consistent manner. This training

will also introduce new volunteers to the

program and its objectives, and will create a

positive social climate for the volunteers.

Such a climate enhances the exchange of

information among participants and the

volunteer coordinator. Training provides the

volunteer with the critical

information necessary to “do the

job right.”

Continuing education and

retraining sessions, in which the

volunteer coordinator reintroduces

standard methodologies and

presents new information,

equipment, data results, or

informative seminars, are also

extremely useful. Such sessions: 

• reinforce proper procedures; 

• correct sloppy or imprecise

techniques; 

• facilitate resolution of

equipment or logistics

problems; 

• allow volunteers to ask

questions after familiarizing

themselves with the field

techniques; 

• encourage a “team effort” 

attitude; 

• make experienced volunteers feel

integral to the program by encouraging

Training Volunteers

A volunteer collects a sample for

bacteria testing. Practicing sampling

techniques in the field is an effective

way to reinforce what is learned in

the classroom (photo by E. Ely).
4-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

them to supply valuable feedback to the

instructors; and 

• provide educational opportunities to the

participants. 

Volunteer training can be divided into three

broad categories. Each has a different

purpose, but together they should complement

one another and make the training program

well-rounded. 

The categories are: 

• introductory training to describe the

program, teach standard methods, and

motivate the volunteers; 

• quality assurance and quality control

(QA/QC) training to ensure consistency

and reliability of data collection; and 

• motivational sessions that encourage

information exchange, identify

problems, and provide a social

atmosphere for participants. 

Although the different sessions will vary in

content, the procedures necessary to present

the material are fairly constant. Volunteer

training may be broken down into five

separate steps, which are described below.

Step 1: Describing the Volunteers’ Duties

Prior to citizen involvement, the program

manager must develop a detailed blueprint of

each volunteer monitoring task. This “job

description” spells out in sufficient detail

every step a volunteer must complete to colVolunteers receive sampling

instructions aboard a boat in

California’s Los Angeles River 

(photo by R. Ohrel).

Sample Job Description: Volunteer Monitoring Coordinator

The Volunteer Monitoring Coordinator has the following responsibilities:

• In consultation with state agency personnel and other interested parties,

determine which waterbodies and which parameters in these waterbodies

will be monitored.

• Recruit volunteers for each project. This will involve contacting interested

groups, elected officials, and possibly businesses and industries in the area.

• Make arrangements for a place to conduct a training session and arrange a

time to suit a majority of volunteer monitors. Train any volunteers who are

unable to attend the training session.

• Keep in close touch with individuals at the beginning of project. Answer

any questions volunteers may have. Read over each data sheet as it comes

in and contact any monitors who seem to be having trouble. Send refill

reagents and replacement equipment upon request.

• If required, enter all data in a suitable computer filing system. Carry out

documentation and verification on the data. Provide plots of data to

monitors and to data users. Carry out preliminary data interpretation. (Other

staff or volunteers may carry out these management activities. If so, the

volunteer monitoring coordinator will assume an advisory role.)

• Provide feedback to participants and data to users. This will involve writing

progress reports and articles for publication in the program newsletter.

• Plan for and carry out quality control sessions. 

• Prepare quarterly reports for the sponsoring agency.

(Excerpted and adapted from USEPA, 1990.)
4-5

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

lect data for each parameter. 

The job description standardizes the data collection process and ensures that each volunteer

samples in a consistent and acceptable manner.

Consistency allows for comparisons of one section of an estuary to another section or between

estuaries. Additionally, when the sampling

methods are consistent, managers can more easily identify data outside the norm and evaluate

whether they result from unusual conditions or

faulty collection techniques. 

There are some critical questions that need to

be answered as you create standard operating

procedures (SOPs), or written protocols to be

used by the volunteers for each parameter that

your program will monitor. The questions

include what water quality parameters are to be

tested and what level of quality is required for

each parameter sampled. These questions are

discussed in detail in Chapters 3, 5, and 6.

Many programs provide their volunteers with

a handbook or manual that has been written

specifically for their program and details the

program SOPs. This written description provides each volunteer with a readily available

reference that clearly describes how to sample

while serving as a reminder of the correct

methodology. Additionally, it helps to minimize

the number of times the volunteer coordinator

has to answer the same questions. Throughout

the handbook, safety should be stressed (see

Chapter 7 for information on volunteer safety).

The handbook should include the steps for

each sampling task. Many of the sampling protocols summarized in this manual are suitable

as basic task descriptions. The author of your

program handbook can excerpt the descriptions

from these chapters and embellish them with

information unique to your program and its data

collection tools and methods. A separate protocol should be drafted for each major parameter

being measured. 

Volunteer coordinators can also use their

handbook to: 

• recruit new volunteers;

• evaluate the ability of volunteers to

complete the monitoring tasks

accurately; and

• assist new programs

in developing their

own protocols. 

Writing the monitoring

tasks provides volunteer

coordinators with the

opportunity to fully

evaluate the job at hand

and improve potentially

troublesome areas. Once

the handbook is completed, volunteer coordinators and a few

volunteers should test and refine the protocols

under field conditions. Volunteer coordinators

and key volunteers should reevaluate the

handbook regularly—especially as the

monitoring program expands to include more

environmental parameters.

Step 2: Planning the Training 

With a completed volunteer handbook,

training sessions can be designed. Usually,

programs will find that group sessions are the

most cost-effective means of training the

volunteers. In some situations, however,

individual instruction may be the only feasible

option. 

Group sessions are preferred for all training

classes because they are generally

inexpensive, efficient, encourage interaction

among the volunteers, and foster enthusiasm

for the program. The training sessions should

be scheduled according to the needs and

availability of your volunteers. If your

volunteers are mainly people who work

during the day, schedule training sessions in

the evenings or weekends. A better option

would be to offer a variety of training times

and let your volunteers pick the time that fits

best into their schedules. 

Training sessions are also the ideal time to

outfit each new volunteer with a complete set

of the required sampling equipment.

Established volunteers may require additional

equipment, blank data sheets, and refills of

the reagents for their analysis kits. 

Volunteers review laboratory techniques (photo

by The Ocean Conservancy).
4-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

If each volunteer is

expected to monitor many

parameters, the instructor

may need to schedule more

than one session. Too much

information presented at a

single session may

overwhelm and eventually

discourage the volunteers.

Training volunteers for

field sampling ideally takes

place in the field. Group

field trips, either for

advanced training or special educational

sessions, are wonderful means of motivating

volunteers while teaching them additional

skills. Furthermore, problems that might not

arise during training conditions in a classroom

may emerge under less predictable field

conditions. Most volunteers are quite

enthusiastic about getting onto the water or

seeing a new area of the estuary and they

often approach their sampling with renewed

enthusiasm after participating in a field trip. 

When volunteers live over a widely

scattered area, require assistance for a special

problem, or are unable to attend a group

session because of work or family obligations,

a volunteer coordinator may need to meet

with them individually. One-on-one training is

certainly more time consuming and

expensive, but it allows the instructor to focus

on the particular problems or needs of a single

volunteer. In return, this individual attention

may help maintain the volunteer’s dedication

to the program.

Training Sessions 

A training session agenda should include: 

• A presentation on goals and objectives of the project. The presentation should include

the reasons for monitoring, historical information on the estuary, the problems it faces,

expected uses of the volunteer data, and how the project will benefit volunteers, the

community, and the state. Let volunteers know how the monitoring program will make

differences in the region and throughout the watershed. 

• A review of what is expected of the participants including how long the training

session will last and the proposed length of the entire volunteer effort.

• Distribution of all equipment, a general explanation of its use, and a discussion of what

equipment is particularly fragile, what constitutes equipment abuse, the replacement

policy and cost, and the return of equipment at the end of the project. 

• A thorough overview of all necessary safety requirements. 

• An overview of the monitoring procedures, preferably with an accompanying slide

show. 

• A demonstration of proper use of monitoring equipment and sampling techniques. The

trainer should demonstrate the proper methods and then circulate among the

participants as they practice the procedures.

• An overview of proper preparation of samples for shipment. 

(Excerpted and adapted from Ellett, 1993.)

A volunteer coordinator reviews instructions

with a team of volunteers (photo by 

K. Register).
4-7

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

Unlike schoolchildren who are trained by adult teachers, adults require a different tact when

it comes to education. If some or all of your program volunteers are adults, then the trainer

needs to appreciate the learning process for adults and design training programs accordingly.

Four pertinent characteristics of adult learners are listed below, accompanied by suggested

ways to address them during the training process. 

• Adults are mature and need to control their learning.

Traditional classroom learning gives the teacher the power while the student is passive,

but adult training should allow the students to have a key role in directing the learning

process. When beginning a training session, present your objectives and session agenda to

the volunteers. Give them an opportunity to discuss and adjust the plan. Get to know your

volunteers before or during the training. Find out why they are participating in the

monitoring program and try to design their “job” to satisfy their interests.

• Adult learning requires a climate that is collaborative, respectful, mutual, 

and informal. 

Adults bring vast personal experiences to the learning process. It is essential that the

trainer recognize and use this experience. Minimize lectures. Retention is increased when

we become actively involved in the learning process. Training sessions should be paced to

allow time for volunteers to hear about the monitoring program, perform the techniques

themselves, and then reflect on the learning by asking and answering questions. Provide

opportunities for group work. Use your experienced volunteers to mentor newer

volunteers. Reinforce your instruction by designing problem-solving exercises for groups

to work on. Traditional classroom teaching assumes that students learn well by listening,

reading, and writing, but in reality people have a variety of learning styles. Some people

learn best through logic and problem solving; others prefer to learn through pictures,

charts, and maps. Some work best on their own, while others work best in groups.

Learning styles are very individualized, and group exercises can be designed to provide a

variety of learning environments. Encourage volunteers to share experiences and

expertise, and provide them with additional learning materials.

• Adults need to test their learning as they go along, rather than receive background

theory and general information. 

Adults need clear connections between content and application so that they can anticipate

how they will use their learning. Start your training session with kits and techniques, and

save the lecture on ecology for later. Let them know how their data will be used, and ask

them what they think needs to be done to improve the estuary. Have them discuss how the

monitoring will help them achieve project and personal goals. Provide time in the training

to discuss how the volunteers will use their new knowledge. Remember that when

volunteers are in the field, curious onlookers may ask them questions about what they are

doing and why. Use role-playing to build their confidence so that they can educate their

communities about the resources they are monitoring. Use other volunteers as trainers,

and provide opportunities for volunteers to take on new challenges.

Understanding Adults as Learners 

(continued)
4-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

• Adults expect performance improvements to result from their learning. 

Adult learning needs to be clearly focused in the present and be “problem centered” rather

than “subject centered.” Help volunteers evaluate your training and their own

performance. Train volunteers in groups. Encourage them to set goals for themselves and

then mentor each other to achieve those goals.

(Excerpted and adapted from Kerr, 1997.)

Step 3: Presenting the Training 

A well-conceived plan for instruction along

with simple handouts is key to a useful

training presentation. Instructors should make

the most effective use of participants’ time.

Volunteers, like most students, appreciate a

well-organized and smoothly paced class.

Four major steps constitute an effective and

lively training session: preparation,

presentation, demonstration, and review. 

Preparation 

Preparation for class is critical. The

sampling protocols provide a basic framework

for the initial training session. With the basic

information in hand, the instructor must then

tailor the lesson to the audience. The

instructor should try to anticipate those

portions of the lesson that may cause

confusion and be prepared to clarify these

areas. Volunteers should be invited to ask

questions throughout the session.

Instructors should make appropriate use of

audiovisual materials to enhance the

presentation. All equipment should be in the

room at the start of the session, in good

working condition, and ready for use. Slides

of the estuary and of volunteers in action are

a good teaching device and tend to hold an

audience’s attention. 

Presentation

Knowing the material thoroughly and

having the information well-organized are

critical to an effective presentation. Ensure a

successful session by using these tips: 

• Be enthusiastic about the subject!

Enthusiasm inspires dedication. 

• Establish a good rapport with the

audience. 

• Get the audience involved in the talk

and keep the presentation lively. 

• Utilize visual aids. 

• Speak loudly enough to be heard

throughout the room and enunciate

clearly. 

• Be humorous. 

• Use eye contact. 

• Encourage questions and comments. 

• Use anecdotes throughout the

presentation. 

• Maintain good posture and positive

body language. 

Volunteers with no background in science

may require additional explanation or

assistance so that they understand the

importance of high quality data collection

methods and the proper use of scientific

equipment. Although separate sessions for

experienced and untrained volunteers are

preferable, some instructors may elect to have

a single session with experienced volunteers

helping those who are new to the program. 

If the pace drags because one or two

volunteers are slow, the rest of the volunteers

may quickly become annoyed and bored.

Slower students may require individualized

attention at a later date. 

(Understanding Adults . . . continued)
4-9

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

Demonstration

Two types of demonstration are effective

training tools: one in which the instructor

shows the techniques to the volunteers and

another in which the students practice the

outlined procedures under the watchful eye of

the instructor. An effective teacher can

incorporate both into a training session. 

The instructor should demonstrate the

sampling protocols. Viewing the execution of

a procedure is more meaningful than simply

reading the instructions. Once the volunteers

are familiar with the techniques, they can then

repeat the procedures under the tutelage of the

instructor. These practice sessions can take

place in the field or classroom and give

volunteers the confidence to transfer these

newly learned skills to their own monitoring

site. 

Review

A good learning session should end with a

review of the material. Summarizing

reinforces the salient points and assists the

volunteers in retaining the information. As in

the training exercise, volunteers should be

invited to ask questions during the review. At

the close of the session, the instructor can

inform participants about upcoming events

and future training opportunities and reiterate

the importance of citizen monitoring and data

collection. 

Step 4: Evaluating the Training 

High quality data reflect successful

volunteer training. To ensure that the sessions

are effective and successful, include written

evaluations as an integral part of the training

process. While an instructor may feel that the

sessions are adequate, only the volunteers

know how much they have learned and

retained. 

Evaluation of the training should include an

assessment of: 

• training techniques and style; 

• information presented; 

• classroom atmosphere; and 

• use of handouts and audiovisual aids. 

Volunteers may provide feedback at the end

of the sessions. The true test of an effective

session, however, is how well the volunteers

perform in the field. A follow-up evaluation

form, sent to participants after a few weeks of

sampling, may pinpoint any weaknesses in the

presentation. 

Members of the monitoring program may

also want to accompany volunteers into the

field and examine their sampling techniques

as they work unassisted. Such spot checks can

identify areas in which the volunteers are

encountering difficulties. It is important to

explain to volunteers that these observation

sessions are an important part of the quality

control that is needed for high quality data.

If large numbers of volunteers are

experiencing problems in carrying out the

sampling protocols, you may want to revise

the format of the training sessions or have a

new instructor take over. The evaluation

process should be ongoing to ensure that all

the sessions consistently meet a high standard. 

Step 5: Follow-Up Training/Providing

Motivation and Feedback 

While the initial training sessions are

designed to give volunteers all the basic skills

to successfully complete their sampling,

training does not stop there. Follow-up

advanced training sessions, either through

one-on-one interaction or with a group of

volunteers, is imperative to keep volunteers

enthusiastic, motivated, and collecting good

data. In some monitoring programs, volunteer

coordinators conduct site visits shortly after

the training session in order to spend time

with each volunteer personally. In addition to

building a closer relationship between the

volunteer and the coordinator, these visits can

answer questions about the monitoring

protocol.

One focus for advanced training sessions

should be quality control (QC), which is

extremely important in all monitoring
4-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

programs. The challenge of volunteer

program managers is to carry out QC

exercises that assess the precision and

accuracy of the data being collected, but are

also fun and interesting for the volunteers.

Experienced volunteer coordinators

recommend turning these quality control

sessions into educational and social

opportunities for the volunteers, while making

sure that volunteers understand why QC is

important. For more on QC, see Chapter 5.

The first QC session should be held about

3-4 months after sampling begins to make

sure that all monitors are sampling and

analyzing in a consistent fashion and to

answer any questions. Thereafter, two QC

sessions should be held each year if sampling

goes on year-round. If sampling is carried out

on a seasonal basis, training sessions for new

monitors and retraining for program veterans

can be held at the beginning of the sampling

period, with a QC session scheduled for the

middle of the season.

Volunteers should be expected to attend all

scheduled sessions. If a volunteer cannot

attend at least one session a year, the

volunteer coordinator (or a trained assistant)

should make a site visit and evaluate the

sampling procedures of the volunteer. 

Quality control exercises should be as

interesting as possible. As two options,

attendees can:

• carry out the tests on the same water

sample with their own equipment the

way they do it at their site, filling out

and submitting a data collection form

with their results; or

• read and record results from previously

set up laboratory equipment and kits,

similar to a classroom laboratory

practical exam.

Data collection forms with the recorded

results are submitted independently. The

results can then be compared to determine

bias. Results from these sessions also measure

how well the group members perform and

how precisely they measure the characteristics

and constituents required.

In addition to ongoing training sessions that

stress quality control, monitoring programs

should offer individualized training to

volunteers who require it. Though less time

efficient than training a group of people, it has

many other benefits. For example, an

individual session: 

• permits the volunteer to ask questions

particular to a site; 

• allows the instructor to solve specific

problems in the field; 

• indicates to the volunteer that his/her

data are important; 

• gives the instructor feedback on training

effectiveness; 

• enhances communication between the

volunteer coordinator and the volunteer; 

• motivates the volunteer; and 

• provides a forum for introducing new

methods. 

Continuous communication with volunteers

is critical. In addition to going into the field

with specific volunteers, the volunteer

coordinator should also consider phoning

other volunteers who may not require face-toface contact. A phone call lets volunteers

know that the volunteer coordinator is

interested in their progress and gives them an

opportunity to ask questions. Informal

gatherings, such as potluck dinners and slide

shows, also give volunteer coordinators an

opportunity to check on the progress of the

participants and answer questions.

Newsletters or updates by way of e-mail are

also excellent ways to keep volunteers

informed.

The success of the program is highly

dependent on maintaining volunteer

motivation and enthusiasm. An apathetic

volunteer will likely not collect good data and

may drop out of the program. The next

section provides suggestions for retaining

volunteers. ■
4-11

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

Finding qualified volunteers and training

them takes work, so losing volunteers on a

regular basis can be a drain on resources.

Your group should have a plan to ensure that

volunteers continue to feel that supporting

your efforts are worth their time. Show them

that the benefits of volunteering outweigh the

costs. Satisfied volunteers will become

advocates for your mission and will help

recruit additional support. Successful

monitoring programs devote significant

resources to activities designed to motivate

their volunteers.

Communicate

Keep direct lines of communication open at

all times using the telephone, personal

memos, and/or some form of newsletter.

Some monitoring groups use e-mail or Web

sites to keep volunteers informed. Be easily

accessible for questions and requests. Give

volunteers a phone number where they can

always leave a message, then respond to calls

promptly. Ask for their advice on general

administrative issues, bring them into the

proofreading process, and help them develop

a sense of shared ownership of the program. 

Recognize the Effort

Give volunteers praise and recognition—it

is the psychological equivalent of a salary!

Recognize their accomplishments through

awards, letters of appreciation, publicity, and

certificates. If at all possible, recognize the

expertise of experienced volunteers by

encouraging them to shoulder increased

responsibilities such as becoming team

leaders or coordinators, carrying out more

advanced tests, or helping with data analyses.

Also, as you keep the local media abreast of

the findings of the monitoring effort, be sure

to include the names of key volunteers.

Offer Educational Opportunities

Provide volunteers with educational

opportunities so that they can continue to

“grow.” Have meetings and regular

workshops where guest speakers can explain

environmental sampling techniques or provide

Backup Monitors

A program should have a backup monitor policy in place to assure data collection continuity.

A backup volunteer can sample at a site when the primary monitor is sick, on vacation, or

for some other reason unable to sample. 

The backup should be trained as rigorously as the primary volunteer so that the data meet

high quality standards. Many programs have strict backup policies in place, with

requirements similar to the following: 

• The backup monitor must be trained by the volunteer coordinator and attend a

minimum of one quality control session every six months. 

• The backup volunteer must be familiar with all the sites that he or she will monitor.

• The backup may monitor at any site but must use the proper data sheet and the kit

assigned to the primary volunteer of the site.

Retaining Volunteers
4-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

information on environmental policies

pertinent to the sampling effort.

Use the Data Your Volunteers Collect

Nothing discourages volunteers more than

seeing that their data are not being used.

Simple analyses and attractive displays of

volunteer data should be prepared and sent to

volunteers as well as to the data users. A Web

site is an excellent place to present volunteer

data.

Keep volunteers informed about all uses of

their data. If they are contributing to a longterm database, prepare annual data summaries

showing the current condition of the estuary

compared to its previous condition. If the data

are used for acute problem identification, send

the volunteers information on areas where

problems have been identified. If the data are

being used to supplement state reports, send

volunteers copies of the report. These actions

will foster continued interest in the program

and serve to educate and inform the

volunteers about the conditions of the estuary.

For more information on using data, see

Chapter 8.

Be Flexible, Open, and Realistic 

Start with a small program that you can

easily handle. Synchronize the monitoring

period to coincide with the period you can

commit to supporting the volunteers. When

starting a program, be frank about the chances

for continued support and inform the group if

resources disappear, or might disappear soon.

Work with the strengths and interests of your

volunteers and search for ways to make the

most of your available resources. Talk with

volunteer coordinators of similar programs

elsewhere to learn new ways to handle

obstacles. ■

Tips on Volunteer Motivation and Incentives

Successful monitoring programs have developed many methods to motivate both new and

long-term volunteers. The following are tips and hints for increasing volunteer participation

and keeping volunteers motivated:

• Remember that you are competing with other organizations for volunteers

and their time.

• Volunteers need a sense of fulfillment. Match volunteer interests and skills with

appropriate jobs. Invite top volunteers to take on leadership responsibilities.

Experienced volunteers can become “captains” to help with training and organization.

Create different “layers” of volunteers.

• Make person-to-person contact.

• Make it easy.

• Make it fun (for example, send a thank-you note saying, “You are a lifesaver!” 

and include some Lifesavers candy). 

• If recruiting volunteers from schools or colleges, the key is getting a committed

teacher to help coordinate. 

• Tell volunteers “what’s in it for them.” Inform them about local water quality problems

and their ownership in the problems/solutions. Show the human connection, and how

their efforts are helping to solve problems.

(continued)
4-13

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

• Present certificates to volunteers when they complete technical training in 

monitoring procedures.

• Be prepared for your volunteers. Have training sessions organized and 

equipment ready. 

• Don’t sign up volunteers if you don’t have work or equipment for them.

• Recruit and train backup volunteers. Some programs recommend having three

volunteers per team, plus backup volunteers. 

• Re-certify volunteers every year.

• Get emergency contact information for all volunteers.

• Recognize that volunteers know their communities. Encourage them to share what

they have learned with schools, press, etc.

• Conduct regular orientation and training sessions. 

• Know that some volunteers have skills beyond serving as monitors (e.g., graphic

design, public relations, making other contacts). Ask them what other talents they

would be willing to share.

• Have your own liability waivers and keep in mind that some state parks, etc. require

that their waivers also be signed. (See Chapter 3 for more information on waivers.)

• Keep equipment in backpacks, boxes, or fabric tote-bags for volunteers to use.

• Build into your volunteer program the capacity for feedback and true volunteer

involvement.

• Reward volunteers after work sessions, sampling seasons, or other milestones with 

a party or other celebration, canoe trips, certificates, etc. 

• Show volunteers and board members the impact their efforts have made by taking

them on boat trips or field trips.

• Some communities sponsor awards, banquets, and other events to recognize

outstanding volunteers. Nominate your volunteers for these honors.

• Thank the volunteers, then thank them again.

(Excerpted and adapted from Calesso, 1999; Closson, 1999; Davies, 1999; Fitzgibbons, 1999; Gerosa,

1999; and Sims, 1999.)

(Tips. . . continued)
Portions of this chapter were excerpted and adapted from:

Ellett, K. 1993. Introduction to Water Quality Monitoring Using Volunteers. 2nd ed. Alliance for the

Chesapeake Bay, Baltimore, MD. 26 pp.

Kerr, M. 1997. “Designing Effective Adult Training.” In: Proceedings of Fifth National Volunteer

Monitoring Conference—Promoting Watershed Stewardship. Aug. 3-7, 1996. University of

Wisconsin-Madison. Madison, WI. EPA Office of Water, Washington, DC. EPA 841-R-97-007.

Web site: http://www.epa.gov/owow/monitoring/vol.html

U.S. Environmental Protection Agency (USEPA). 1990. Volunteer Water Monitoring: A Guide for

State Managers. EPA 440/4-90-010. August. Office of Water, Washington, DC. 78 pp.

Other references:

Calesso, D. 1999. “Volunteer Training, Motivation, Incentives.” In: Meeting Notes—U.S.

Environmental Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop:

Volunteer Estuary Monitoring: Wave of the Future. Toms River, NJ: April 14-16, 1999.

Closson, J. 1999. “Volunteer Training, Motivation, Incentives.” In: Meeting Notes—U.S.

Environmental Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop:

Volunteer Estuary Monitoring: Wave of the Future. Astoria, OR: May 19-21, 1999.

Cook, J.S. 1989. The Elements of Speechwriting and Public Speaking. MacMillan Publishing

Company. New York. 242 pp. 

Davies, B. 1999. “Volunteer Training, Motivation, Incentives.” In: Meeting Notes—U.S.

Environmental Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop:

Volunteer Estuary Monitoring: Wave of the Future. Astoria, OR: May 19-21, 1999.

Ely, E. 1992. “Training and Testing Volunteers.” The Volunteer Monitor 4(2): 3-4.

Fitzgibbons, J. 1999. “Volunteer Training, Motivation, Incentives.” In: Meeting Notes—U.S.

Environmental Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop:

Volunteer Estuary Monitoring: Wave of the Future. Mobile, AL: March 17-19, 1999.

Gerosa, A. 1999. “Volunteer Training, Motivation, Incentives.” In: Meeting Notes—U.S.

Environmental Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop:

Volunteer Estuary Monitoring: Wave of the Future. San Pedro, CA: February 22-24, 1999.

Sims, G. 1999. “Volunteer Training, Motivation, Incentives.” In: Meeting Notes—U.S.

Environmental Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop:

Volunteer Estuary Monitoring: Wave of the Future. Mobile, AL: March 17-19, 1999.

U.S. Environmental Protection Agency (USEPA). 1991. Volunteer Lake Monitoring: A Methods

Manual. EPA 440/4-91-002. Office of Water, Washington, DC. 121 pp.

U.S. Environmental Protection Agency (USEPA). 1997. Proceedings of Fifth National Volunteer

Monitoring Conference-Promoting Watershed Stewardship. Aug. 3-7, 1996. University of

Wisconsin-Madison. Madison, WI. EPA Office of Water, Washington, DC. EPA 841-R-97-007. 

Web site: http://www.epa.gov/owow/monitoring/vol.html.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A Methods

Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

4-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 4: Recruiting, Training, and Retaining Volunteers

References and Further Reading
Chapter 5

Quality Assurance Project Planning

While information about an estuary’s health is valuable, many government

agencies, universities, and other groups are reluctant to use volunteer data. 

Why? Volunteer monitoring organizations sometimes overlook a critical fact:

reliable data means everything. Unless data are collected and analyzed using

acceptable methods, potential users are less likely to employ the data. A quality

assurance project plan (QAPP) is vital to overcoming this obstacle.
Photos (l to r): Tillamook Bay National Estuary Project and Battelle Marine Science Lab, U.S. Environmental Protection Agency,

U.S. Environmental Protection Agency
5-1

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

While information about an estuary’s health is valuable, many government

agencies, universities, and other groups are reluctant to use volunteer data. Why?

Volunteer monitoring organizations sometimes overlook a critical fact: reliable

data means everything. Unless data are collected and analyzed using acceptable

methods, potential users are less likely to employ the data. A quality assurance

project plan (QAPP) is vital to overcoming this obstacle.

This chapter examines the elements of a QAPP. In the process, it reviews basic

concepts that must be understood before developing any QAPP. 

For comprehensive instructions and useful examples for creating a QAPP, along

with a sample QAPP form, the reader should refer to The Volunteer Monitor’s

Guide to Quality Assurance Project Plans (USEPA, 1996).

Overview
5-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Although the goals and objectives of

volunteer projects vary greatly, virtually all

volunteers hope to educate themselves and

others about water quality problems and

thereby promote a sense of stewardship for

the environment. Many projects, in fact,

establish these as their goals. Such projects

might be called primarily education-oriented.

Other projects seek a more active role in the

management of local water resources and

therefore strive to collect data that can be

used in making water quality management

decisions. Common uses of volunteer data

might include local planning decisions (e.g.,

identifying where to route a highway); local

priority setting (e.g., determining which

seagrass beds require restoration); screening

for potential pollution problems (which might

then be investigated more thoroughly by

water quality agencies); and providing data

for state water quality reports (which might

then be used for statewide or national priority

setting). Projects doing this type of

monitoring are called primarily data-oriented. 

One of the most difficult issues facing dataoriented volunteer monitoring programs today

is data credibility. Some potential users of

volunteer data mistakenly believe that only

professionally trained scientists can conduct

sampling and produce accurate and useful

results. Potential data users are often skeptical

about volunteer data—they may have doubts

about the goals and objectives of the project;

how volunteers were trained; how samples

were collected, handled, and stored; or how

data were analyzed and reports written. Given

proper training and supervision, however,

dedicated volunteers CAN collect high

quality data that is:

• consistent over time throughout the

project’s duration, regardless of how

many different monitors are involved in

collecting the data;

• collected and analyzed using

standardized and acceptable techniques;

and 

• comparable to data collected in other

assessments using the same methods.

The quality assurance project plan is a key

tool in breaking down this barrier of

skepticism. ■

The Importance of High Quality Data

What Is a Quality Assurance Project Plan?

The QAPP is a document that outlines the

procedures necessary to ensure that collected

and analyzed data meet project requirements.

It serves not only to convince skeptical data

users about the quality of the project’s

findings, but also to record methods, goals,

and project implementation steps for current

and future volunteers and for those who may

wish to use the project’s data over time.

Volunteer monitoring projects must adopt

protocols that are straightforward enough for

volunteers to master, yet sophisticated enough

to generate data of value for resource

managers. This delicate and difficult path

cannot be successfully navigated without a

QAPP that details a project’s standard

operating procedures (SOPs) in the field and

lab, outlines project organization, and

addresses issues such as training

requirements, instrument calibration, and

internal checks on how data are collected,

analyzed, and reported. Just how detailed

such a plan needs to be depends to a large

extent on the goals of the volunteer

monitoring project. For example, if you want

to use your data to screen for problems so that

you can alert water quality agencies, you may

need only a basic plan. If, however, you want
5-3

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

your data to support enforcement, guide

policy decisions, or survive courtroom

scrutiny, then a detailed plan is essential

(Mattson, 1992).

Developing a QAPP is a dynamic,

interactive process that should ideally involve

quality assurance experts, potential data users,

and members of the volunteer monitoring

project team. The process is most effective

when all participants fully contribute their

talents to the effort, know their individual

responsibilities for developing the QAPP, and

understand the group’s overall purpose and

goals.

While it is a challenging and somewhat

difficult process, the successful development

and institution of a QAPP can be extremely

rewarding. This chapter encourages and

facilitates the development of volunteer

estuary QAPPs by presenting explanations

and examples. Readers are urged to consult

the resources listed at the end of this chapter

and to contact their state or U.S.

Environmental Protection Agency (EPA)

regional quality assurance staff for specific

information or guidance on their projects. ■

Why Develop a QAPP?

The QAPP is an invaluable planning and

operating tool that should be developed in the

early stages of the volunteer monitoring

project.

Any monitoring program sponsored by EPA

through grants, contracts, or other formal

agreement must have an approved QAPP. The

purpose of this requirement is to ensure that

the data collected by monitoring projects are

of known and suitable quality and quantity. 

Even if a volunteer monitoring project does

not receive financial support from government

agencies, the coordinating group should still

consider developing a QAPP. This is

especially true if it is a data-oriented project

and seeks to have its information used by

state, federal, or local resource managers. Few

water quality agencies will use volunteer data

unless methods of data collection, storage,

and analysis have been documented. 

Clear and concise documentation of

procedures also allows newcomers to the

project to quickly become familiar with the

monitoring, using the same methods as those

who came before them. This is particularly

important to a volunteer project that may see

volunteers come and go, but intends to

establish a baseline of water quality

information that can be compared over time. 

Finally, written procedures in a QAPP can

help ensure volunteer safety (Williams, 1999).

Field safety requirements can be made part of

standard operating practices, and proper

training for equipment operation—a key

element in any QAPP—takes user safety into

account. ■

QAPPs and STORET

An updated, user-friendly version of EPA’s

national water and biological data storage

and retrieval system, STORET, is now

available. With STORET, volunteer

programs can “feed” data to a centralized

file server which permits national data

analyses and through which data can be

shared among organizations. A specific set of

quality control measures is required for any

data entered into the system to aid in data

sharing. For more information, see the EPA

Web page at www.epa.gov/storet.
5-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

The coordinator of a volunteer monitoring

program is likely to be involved in many

aspects of project planning, sample collection,

laboratory analysis, data review, and data

assessment. The coordinator should be

considering quality assurance and quality

control in every one of these steps.

Quality assurance (QA) refers to the

overall management system that includes the

organization, planning, data collection, quality

control, documentation, evaluation, and

reporting of your group’s activities. QA

provides the information you need to ascertain

the quality of your data and whether it meets

the requirements of your project. It also

ensures that your data will meet defined

standards of quality with a stated level of

confidence.

Quality control (QC) pertains to the

routine technical activities in a project. The

purpose of QC is, essentially, error control.

Since errors can occur in the field, the

laboratory, or the office, QC must be part of

each of these functions and should include:

Internal quality control: a set of measures

that the project undertakes among its own

samplers and within its own lab to identify and

correct analytical errors. Examples include:

• lab analyst training and certification;

• proper equipment calibration and

documentation;

• laboratory analysis of samples with

known concentrations or repeated

analysis of the same sample; and 

• collection and analysis of multiple

samples from the field.

External quality control: a set of measures

that involves both laboratories and people

outside of the program. Measures may

include:

• performance audits by outside

personnel;

• collection of samples by people outside

the program from a few of the same

sites and at the same time as the

volunteers; and 

• splitting some of the samples for

analysis at another lab.

Together, QA and QC help you to produce

data of known quality, enhance the credibility

of your group in reporting monitoring results,

and ultimately save time and money.

However, a good QA/QC program is only

successful if everyone consents to follow it

and if all project components are available in

writing. The QAPP is the written record of

your QA/QC program.

When formulating a QAPP, several

measures will help to evaluate sources of

variability and error and thereby increase

confidence in the data. These measures are

precision, accuracy, representativeness,

completeness, comparability, and sensitivity.

Precision

Precision is the level of agreement among

repeated measurements of the same parameter

on the same sample or on separate samples

collected as close as possible in time and

place (Figure 5-1). It tells you how consistent

and reproducible your methods are by

showing how close your measurements are to

each other. It does not mean that the sample

results actually reflect the “true” value, but

rather that your sampling and analysis are

giving consistent results under similar

conditions. 

Precision can be measured by calculating the

standard deviation, relative standard deviation

(RSD), or the relative percent difference

(RPD). Examples of each calculation are

shown in Tables 5-1, 5-2, and 5-3.

The standard deviation (Table 5-1) is used

Basic Concepts

Inaccurate and Precise

Accurate and Precise

Accurate and Imprecise

Inaccurate and Imprecise

Figure 5-1. Accuracy

and precision.
5-5

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

to describe the variability of your data points

around their average value. In case you’re a

bit put off by the math in Table 5-1, you

might be happy to know that many calculators

can calculate standard deviation for you! Very

similar data values will have a small standard

deviation, while widely scattered data will

have a much larger standard deviation.

Therefore, a small standard deviation

indicates high data precision. 

The RSD, or coefficient of variation (Table

5-2), expresses the standard deviation as a

percentage. This measurement is generally

easier for others to understand. Similar to

standard deviation, your measurements

become more precise as the RSD gets smaller.

When you have only two replicate samples,

determine precision by calculating the relative

percent difference (RPD) of the two samples

(Table 5-3). Again, the smaller the relative

percent difference, the more precise your

measurements will be.

Table 5-1. Example calculation of standard deviation. A low value for standard deviation indicates high precision

data. (Adapted from USEPA, 1996.)

The Volunteer Estuary Monitoring Project wants to determine the precision of its temperature

assessment procedure. They have taken 4 replicate samples:

Replicate 1 (X1) = 21.1°C

Replicate 2 (X2) = 21.1°C

Replicate 3 (X3) = 20.5°C

Replicate 4 (X4) = 20.0°C

To determine the Standard Deviation (S), use the following formula: 

where Xi = measured value of the replicate; X– = mean of replicate measurements; n = number

of replicates; and ∑ = the sum of the calculations for each measurement value—in this case,

X1 through X4.

First, figure out the mean, or average, of the sample measurements. Mean = (X1 + X2 + X3 +

X4) ÷ 4. In this example, the mean is equal to 20.68°C.

Then, for each sample measurement (X1 through X4), calculate the next part of the formula.

For X1 and X2, the calculation would look like this:

(21.1 - 20.68)2 = (-0.42)2 = 0.1764 = 0.0588

4-1 3 3

For X3, the calculation would be 0.0108; and for X4, it would be 0.1541.

Finally, add together the calculations for each measurement and find the square root of the

sum: 0.0588 + 0.0588 + 0.0108 + 0.1541 = 0.2825. The square root of 0.2825 is 0.5315. 

So, the standard deviation for temperature is 0.532 (rounded off). 

S = ∑ (Xi

-X) n 2

i=1 n-1
5-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Accuracy

Accuracy is a measure of confidence in a

measurement (Figure 5-1; Table 5-4). As the

difference between the measurement of a

parameter and its “true” or expected value

becomes smaller, the measurement becomes

more accurate. Repeated measurements that

result in values at or near the “true value”

would be considered accurate and precise.

Measurement accuracy can be determined

by comparing a sample that has a known

value, such as a standard reference material or

a performance evaluation sample, to a

volunteer’s measurement of that sample.

Increasingly, however, some scientists,

especially those involved with statistical

analysis of measurement data, have begun to

use the term “bias” to reflect this error in the

measurement system and to use “accuracy” as

indicating both the degree of precision and

bias. For the purpose of this document, the

term “accuracy” will be used to describe how

close a measurement is to a standard value or

the true value.

If we use the same measurements as in the standard deviation example (Table 5-1), we can

determine the Relative Standard Deviation (RSD), or coefficient of variation, using the

following formula:

RSD = S x 100

X ̄

where S = standard deviation, and X– = mean of replicate samples.

We know that S = 0.5315 and that X– = 20.68. So, the RSD = 2.57. This means that our 

measurements deviate by about 2.57%.

If the project had only two replicates (21.1oC and 20.5oC, for example), we would use the

Relative Percent Difference (RPD) to determine precision, using the following formula:

RPD =

(X1 - X2) x 100

(X1 + X2) ÷ 2

where X1 = the larger of the two values, and X2 = the smaller of the two values. In this

example, X1 = 21.1o

and X2 = 20.5o. The calculation would look like this:

RPD = (21.1 - 20.5) x 100 = 60.00 = 2.88

(21.1 + 20.5) ÷ 2 20.8

So, in this example, the RPD between our sample measurements is 2.88%.

Table 5-2. Example calculation of relative standard deviation (RSD). A low RSD value indicates high precision

data. (Adapted from USEPA, 1996.)

Table 5-3. Example calculation of relative percent difference (RPD). A low RPD indicates high precision data.

(Adapted from USEPA, 1996.)
5-7

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

For many parameters such as Secchi depth,

no standard reference or performance

evaluation samples exist. In these cases, the

trainer’s results may be considered the

reference value to which the volunteer’s

results are compared. This process will help

evaluate if the volunteer measurements are

biased as compared to the trainer’s. 

If you are monitoring biological conditions

by collecting and identifying specimens,

maintaining a voucher collection is a good

way to determine if your identification

procedures are accurate. The voucher

collection is a preserved archive of the

organisms that your volunteers have collected

and identified. An expert taxonomist can then

provide a “true” value by checking the

identification in the voucher collection. In

addition to preserved specimens, the

collection may involve photography or

microscopy. 

Attendance at QC training sessions is required for Volunteer Estuary Monitoring Project field

teams. In the field, monitors use a pH kit, which covers a full range of expected pH values.

During a recent training session, the monitors recorded the following results when testing a

pH standard buffer solution of 7.0 units:

7.5 7.2 6.5 7.0

7.4 6.8 7.2 7.4

6.7 7.3 6.8 7.2

In this example, the volunteer coordinator may wish to evaluate accuracy in two ways:

Group Accuracy

To determine the accuracy of the full group of volunteers, the coordinator can compare the

average of all sample values to the true value, according to the equation:

Group accuracy = average value – true value

In this case, the average of these measurements is equal to 7.08 units. Since we know that the

reference or “true” value is 7.0 units, the difference between the average pH value is “off” or

biased by + 0.08 units. The volunteer program’s QAPP should specify whether this level of

accuracy is satisfactory for the data quality objectives of the project.

Individual Accuracy

While the average pH value calculated above is 7.08 units, a quick scan reveals that several

measurements are up to 0.5 units from the true value. Such individual differences from the

true value may not fall within an acceptable limit of accuracy, but they are somewhat

“hidden” when the group accuracy is calculated. Simply calculating the group accuracy could

overlook particularly erroneous data that should be addressed.

To assess the accuracy of individual measurements, the coordinator should use the following

equation:

Individual accuracy = individual value – true value

The possible cause(s) of individual accuracy values that do not fall within the program’s

QAPP should be determined and remedied.

Table 5-4. Example calculations of accuracy. (Redrawn and adapted from USEPA, 1996.)
5-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

It is important to note that the relationship

between a voucher collection and accurate

identification cannot be expressed numerically

in your QAPP. Rather, the QAPP should

indicate that you have a voucher collection

and describe how it is used to evaluate

identification accuracy in your program.

Representativeness

Representativeness is the extent to which

measurements actually depict the true

environmental condition or population you are

evaluating. The questions asked in your

QAPP will be the guide for defining what

constitutes a representative sample. 

A number of factors may affect the

representativeness of your data. Are your

sampling locations indicative of the

waterbody? Data collected just below a pipe

outfall, for example, is not representative of

an entire estuary. Similarly, a sample collected

in August is not representative of year-round

conditions. Other potential errors, such as lab

mistakes, data entry errors, or the use of the

wrong type of sample container, may also

affect data representativeness. 

Completeness

Completeness is a measure of the number

of samples you must take to be able to use the

information, as compared to the number of

samples you originally planned to take. Since

there are many reasons why your volunteers

may not collect as many samples as planned

(e.g., equipment failure, weather-related

problems, sickness, faulty handling of the

samples), as a general rule you should try to

take more samples than you determine you

actually need. This issue should be discussed

with your QAPP team and by peer reviewers

before field activities begin.

Completeness requirements can be lowered

if extra samples are factored into the project.

The extra samples, in turn, increase the

likelihood of more representative data.

Completeness is usually expressed as a

percentage (Table 5-5), accounting for the

number of times that the volunteers did not

collect data. An 80-90 percent rate of

collection is usually acceptable.

Table 5-5. Example calculation of completeness. (Adapted from USEPA, 1996.)

The Volunteer Estuary Monitoring Project planned to collect 20 samples, but because of

volunteer illness and a severe storm, only 17 samples were actually collected. Furthermore, 

of these, two samples were judged invalid because too much time elapsed between sample

collection and lab analysis. Thus, of the 20 samples planned, only 15 were judged valid.

The following formula is used to determine Percent Completeness (%C):

%C = v

T x 100

where v = the number of planned measurements judged valid, and T = the total number of

measurements.

In this example, v = 15 and T = 20. In this case, percent completeness would be 75 percent.

Notice that this percent completeness does not fall within the usually accepted range of 80-90

percent.
5-9

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Comparability

Comparability is the extent to which data

from one study can be compared directly to

either past data from the current project or data

from another study. For example, you may wish

to compare two seasons of summer data from

your project or compare your summer data set

to one collected ten years ago by state water

quality scientists. The key to data comparability

is to follow established protocols or standard

operating procedures. Comparing data also

requires you to consider the conditions under

which the samples were collected, including,

for example, the season, time of day, and adjacent land uses.

Using standardized sampling and analytical

methods, units of reporting, and site selection

procedures helps ensure comparability.

However, it is important to keep in mind that

some types of monitoring rely heavily on best

professional judgment and that standard methods may not always exist.

Sensitivity

Sensitivity refers to the capability of a

method or instrument to discriminate between

different measurement levels. The more sensitive a method is, the better able it is to detect

lower concentrations of a water quality variable.

Sensitivity is related to detection limit, the

lowest concentration of a given pollutant that

your methods or equipment can detect and

report as greater than zero. Readings that fall

below the detection limit are too unreliable to

use in your data set. Furthermore, as readings

approach the detection limit (i.e., as they go

from higher, easier-to-detect concentrations to

lower, harder-to-detect concentrations), they

become less and less reliable. Manufacturers

generally provide detection limit information

with their high-grade monitoring equipment,

such as meters; however, volunteer groups

should test the equipment themselves—using

standards of progressively lower concentrations—to understand where the meter or

method begins to have unacceptable accuracy.

Preassembled monitoring kits also usually

come with information indicating the measurement range that applies. The measurement range is the range of reliable measurements of an instrument or measuring device.

For example, you might purchase a kit that is

capable of detecting pH between 6.1 and 8.1.

If acidic conditions (below 6.0) are a problem

in the waters you are monitoring, you will

need to use a kit or meter that is sensitive to

the lower pH readings.

Because all projects have different goals, data

users and uses, capabilities, and methods, there

are no universal levels of precision, accuracy,

representativeness, completeness, comparability, and sensitivity that are acceptable for every

monitoring project. You should consult your

advisory panel, data users, support laboratory,

and peer reviewers to determine acceptance criteria for your monitoring project. ■
5-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Contamination is a common source of error

in both sampling and analytical procedures.

QC samples help you identify when and how

contamination might occur and assess the

overall precision and accuracy of your data.

The decision to accept data, reject it, or accept

only a portion of it should be made after

analysis of all QC data. 

For most projects, there is no set number of

field or laboratory QC samples which must be

taken; the general rule is that 10 percent of all

samples should be QC samples. Any

participating laboratory must also run its own

QC samples. For a new monitoring project or

analytical procedure, it is a good idea to

increase the number of QC samples (up to 20

percent) until you have full confidence in the

procedures you are using.

Several different types of QC and

assessment measures are presented below

(USEPA, 1996; USEPA, 1997).

Internal Checks

Internal checks are performed by the project

field volunteers, staff, and lab. 

Field Blanks

A field blank (also known as a trip blank) is

a “clean” sample, produced in the field, used

to detect analytical problems during the whole

process (sampling, transport, and lab

analysis). To create a field blank, take a clean

sampling container with “clean” water (i.e.,

distilled or deionized water that does not

contain any of the substance you are

analyzing) to the sampling site. Other

sampling containers will be filled with water

from the site. Except for the type of water in

them, the field blank and all site samples

should be handled and treated in the same

way. For example, if your method calls for the

addition of a preservative, this should be

added to the field blank in the same manner

as the other samples. When the field blank is

analyzed, it should read as being free of the

analyte (parameter being tested) or, at a

minimum, the reading should be a factor of 5

below all sample results.

Negative and Positive Plates (for Bacteria)

A negative plate results when the buffered

rinse water (the water used to rinse down the

sides of the filter funnel during filtration) has

been filtered the same way as a sample. This

is different from a field blank in that it

contains reagents used in the rinse water.

There should be no bacteria growth on the

filter after incubation. Bacteria growth

indicates laboratory contamination of the

sample. 

Positive plates result when water known to

contain bacteria (such as wastewater treatment

plant influent) is filtered the same way as a

sample. There should be plenty of bacteria

growth on the filter after incubation. It is used

to detect procedural errors or the presence of

contaminants in the laboratory analysis that

might inhibit bacteria growth. 

Field Replicates

Replicate samples are obtained when two or

more samples are taken from the same site, at

the same time, using the same method, and

independently analyzed in the same manner.

When only two samples are taken, they are

sometimes referred to as duplicate samples.

These types of samples are representative of

the same environmental condition and can be

used to detect the natural variability in the

environment, the variability caused by field

sampling methods, and laboratory analysis

precision. 

Lab Replicates

A lab replicate is a sample that is split into

subsamples at the lab. Each subsample is then

analyzed using the same technique and the

results compared. They are used to test the

Quality Control and Assessment
5-11

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

precision of the laboratory measurements. For

bacteria, they can be used to obtain an

optimal number of bacteria colonies on filters

for counting purposes. 

Spiked Samples

Spiked samples are samples to which a

known concentration of the analyte of interest

has been added. Spiked samples are used to

measure accuracy. If this is done in the field,

the results reflect the effects of preservation,

shipping, laboratory preparation, and analysis.

If done in the laboratory, they reflect the

effects of the analysis procedure. The percent

of the spike material that is detected in the

sample is used to calculate analytical

accuracy.

Calibration Blank

A calibration blank is deionized water

processed like any of the samples; it is the

first “sample” analyzed and is used to set the

instrument to zero. A calibration blank is also

used to check the measuring instrument

periodically for “drift” (the instrument should

always read “0” when this blank is measured).

It can also be compared to the field blank to

pinpoint where contamination might have

occurred. 

Calibration Standards

Calibration standards are used to calibrate a

meter. They consist of one or more “standard

concentrations” (made up in the lab to

specified concentrations or provided by any

number of supply houses—see Appendix C)

of the indicator being measured, one of which

is the calibration blank. Calibration standards

can be used to calibrate the meter before

running the test, or they can be used to

convert the units read on the meter to the

reporting units (e.g., converting absorbance to

milligrams per liter). 

Helpful Hint

In addition to being used for meter

calibration, standard reference material (in

the form of solids or solutions with a

certified known concentration of pollutant)

can be used to check the accuracy of a

procedure and the freshness of the reagents

(chemicals) in test kits. If a known standard

solution is tested and gives the correct

concentration test result, the reagents are

working properly and the procedure is

being followed correctly.

External Checks 

Non-volunteer field staff and a lab (also

known as a “quality control lab”) perform

external checks. The results are compared

with those obtained by the project lab. 

External Field Duplicates

An external field duplicate is a duplicate

sample collected and processed by an

independent (e.g., professional) sampler or

team at the same place and the same time that

the volunteers collect and process their

regular water samples. It is used to estimate

sampling and laboratory analysis precision. 

Split Samples

A split sample is one that is divided equally

into two or more sample containers and then

analyzed by different analysts or labs. The

results are then compared.

Samples should be thoroughly mixed before

they are divided. Large errors can occur if the

analyte is not equally distributed into the two

containers. A sample can be split in the field,

called a field split, or in the laboratory—a lab

split. The lab split measures analytical precision, while the field split measures both analytical and field sampling precision. Split samples

can also be submitted to two different laboratories for analysis to measure the variability in

results between laboratories independently

using the same analytical procedures.
5-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Outside Lab Analysis of Duplicate Samples

Either internal or external field duplicates

can be analyzed at an independent lab. The

results should be comparable with those

obtained by the project lab. 

Knowns

The quality control lab sends samples for

selected indicators, labeled with the

concentrations, to the project lab for analysis

prior to the first sample run. These samples

are analyzed and the results compared with

the known concentrations. Problems are

reported to the quality control lab. 

Unknowns

The quality control lab sends samples to the

project lab for analysis for selected indicators,

prior to the first sample run. The concentrations of these samples are unknown to the

project lab. These samples are analyzed and

the results reported to the quality control lab.

Discrepancies are reported to the project lab

and a problem identification and solving

process follows. 

Table 5-6 shows the applicability of

common quality control measures to several

water quality variables covered in this

manual. ■

Table 5-6. Common quality control measures and their applicability to some water quality parameters. (Adapted from USEPA, 1997.)

Dissolved Nutrients pH Total Temp. Salinity/ Turbidity Total Bacteria

Oxygen Alkalinity Conductivity Solids

X X X X X

X

X X X X X X X X X

X X X X X X X Xb

X X X

X X X

Xa X X X X

X X X X X X X

X X X X X X X

X X X X X X X

X X X X X X X

X X X X X X X

Internal Checks

Field blanks

Neg./ pos. plates

Field replicates

Lab replicates

Spiked samples

Calibration blank

Calibration standard

External Checks

Ext. field duplicates

Split samples

Outside lab analysis

Knowns

Unknowns

a—using an oxygen-saturated sample

b—using subsamples of different sizes
5-13

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Developing a QAPP is a dynamic, interactive

process. Seek as much feedback as possible

from those who have gone before you in the

QAPP development process. You will be investing a substantial amount of time and energy, but

don’t be discouraged: the person who writes the

QAPP is usually the one who ends up with the

most technical expertise and monitoring

insights. Your efforts will pay off in a living

document that helps current and future volunteers, staff, and data users understand exactly

how your project works.

The purpose of this section is to discuss the

steps a volunteer monitoring program might

take in preparing a QAPP (Table 5-7). It is recommended that you consult your data users,

such as the state or county water quality agency,

regarding their QAPP requirements. In fact,

many states have prepared QAPPs that, if adopted by your group, can save a great deal of time.

If you are receiving EPA grant or contract

money to conduct your monitoring, you must

also submit your QAPP to EPA for approval.

Working with water quality agencies, EPA, and

other potential data users to develop your QAPP

increases the likelihood that your data will actually be used to make management decisions.

Table 5-7. Steps to develop a QAPP (USEPA, 1996).

Step 1: Establish a QAPP Team

Pull together a small team of 2-3 people

who can help you develop the QAPP. Include

representatives from groups participating in

the monitoring project who have technical

expertise in different areas of the project.

Take time to establish contact with your

state, local, or EPA quality assurance officer

or other experienced volunteer organizations.

Remember: If you are receiving any EPA

funding through a grant or contract, EPA must

approve your QAPP. However, even if EPA

approval isn’t needed, you can consult with

EPA representatives for advice; they may

have resources that can help you. Ask your

contacts if they will review your draft plan.

Step 2: Determine the Goals and

Objectives of Your Project

Why are you developing this monitoring

project? Who will use its information, and

how will it be used? What will be the basis

for judging the usability of the data collected?

If you don’t have answers to these questions,

you may flounder when it comes time to put

your QAPP down on paper.

Project goals could include, for example:

• identifying trends in an estuary to

determine if non-indigenous species

occurrences are on the rise;

• monitoring in conjunction with the

county health department to be sure a

beach is safe for swimmers;

• monitoring the effectiveness of a

submerged aquatic vegetation (SAV)

restoration project; or

• teaching local high school students

about water quality.

Write down your goal. The more specific

your project’s goal, the easier it will be to

design a QAPP. Identify the objectives for

your project—that is, the specific statements

of how you will achieve your goal. For

Developing a QAPP

1. Establish a QAPP team.

2. Determine the goals and objectives of

your project.

3. Collect background information.

4. Refine your project.

5. Design your project’s sampling,

analytical, and data requirements.

6. Develop an implementation plan.

7. Draft your standard operating

procedures and QAPP.

8. Solicit feedback on your draft SOPs

and QAPP.

9. Revise your QAPP and submit it for

final approval.

10. Begin your monitoring project.

11. Evaluate and refine your QAPP.
5-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

example, if your project’s goal is to monitor

an SAV restoration project, your objectives

might be to collect three years of data on SAV

beds, turbidity, algae, and nutrients, and to

develop yearly reports for state water quality

and fish and wildlife agencies.

Each use of volunteer data has potentially

different requirements. Knowing the use of

the collected data will help you determine the

right kind of data to collect and the level of

effort necessary to collect, analyze, store, and

report the data. 

While sophisticated analyses generally yield

more accurate and precise data, they are also

more costly and time consuming. One should

closely examine the program budget when

forming the data quality objectives. Decisions

regarding the ultimate objectives must always

strike a balance between the needs of the data

users and the fiscal constraints of the program

(Figure 5-2). If the program’s main goal is to

supplement state-collected data, for example,

the extra expense may be worthwhile.

Programs with an educational or participatory

focus can often use less sensitive equipment,

analyses, or methodologies and still meet their

data objectives. 

Step 3: Collect Background Information

As you learn more about the area you are

choosing to monitor, you will be better able to

design an effective monitoring project. Begin

by contacting programs and agencies that

might already monitor in your area. Talk to

the state water quality agency, the county

and/or city environmental office, local

universities, and neighboring volunteer

monitoring programs. Ask about their

sampling locations, the parameters they

monitor, and the methods they use.

If those groups are already monitoring in

your chosen area, find out if they will share

their data, and identify what gaps exist that

your project could fill. If no monitoring is

ongoing, find out what kind of data your local

or state agencies could use (if one of your

goals is that these agencies use your data),

where they would prefer you to locate your

sampling sites, and what monitoring methods

they recommend. Government agencies are

not likely to use your data unless it fills a

gap in their monitoring network and was

collected using approved protocols.

A watershed survey can help you set the

foundation for your monitoring project

design. This is simply a practical investigation

of how the watershed works, its history, and

its stressors. For information on conducting a

watershed survey, consult the USEPA (1997)

and Maine DEP (1996) references listed at the

end of this chapter.

Step 4: Refine Your Project

Once you have collected background

information for your project and coordinated

with potential data users, you may find it

necessary to refine your original goals and

objectives. You might have found, for

example, that your state already monitors

SAV and algae in your estuary. In that case,

your project might better examine nutrient

inputs from tributaries or other parameters.

DQOs

Time &

Money

Data

Uncertainty

Less

Resources

More

Uncertainty

DQOs

Data

Uncertainty

Time &

Money

More

Resources

Less

Uncertainty

Figure 5-2. The

balancing act of data

quality objectives.

Volunteer programs

must balance data

quality needs with

financial limitations,

understanding that as

data quality becomes

more important, the

resources necessary to

get the data are likely to

increase. (Adapted from

USEPA, 1987.)
5-15

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Don’t hesitate to reevaluate your project

goals and objectives. Now is the best possible

time to do so-before you invest time, money,

and effort in equipment purchases, training,

grant proposals, and QAPP development.

Step 5: Design Your Project’s Sampling,

Analytical, and Data Requirements

Once you feel comfortable with your project’s goals and objectives and have gathered

as much background information as possible

on the area you will be monitoring, it is time

to focus on the details of your project.

Convene a planning committee consisting of

the project coordinator, key volunteers,

scientific advisors, and data users, along with

your QAPP team. This committee should

address the following questions:

• What parameters or conditions will you

monitor, and which are most important

to your needs? Which are of secondary

importance?

• How good does your monitoring data

need to be?

• How will you pick your sampling sites,

and how will you identify them over

time?

• What methods or protocols will you use

for sampling and analyzing samples?

• When will you conduct the monitoring?

• How will you manage your data and

ensure that your data are credible?

As a general rule, it is a good idea to start

small and build to a more ambitious project as

your volunteers and staff grow more

experienced. 

Step 6: Develop an Implementation Plan

Decide the particulars—the who’s and

when’s of your project. Determine who will

carry out the individual tasks such as

volunteer training, data management, report

generation, assuring lab and field quality

assurance, and recruiting volunteers. If you

send your samples to an outside lab, choose

the lab and specify why you chose it.

Set up schedules for when you will recruit

and train volunteers, conduct sampling and

lab work, produce reports, and report back to

volunteers or the community.

Step 7: Draft Your Standard Operating

Procedures and QAPP

Now is the time to actually write your

standard operating procedures (SOPs) and

develop a draft QAPP. SOPs are the details on

all the methods you expect your volunteers to

A Word About Metadata

The term metadata is loosely defined as

“data about data.” It is information that

helps characterize the data that volunteers

collect. Metadata answer who, what,

when, where, why, and how about every

facet of the data being documented

(USGS Web site). This information will

help others understand exactly how the

data was obtained. 

Most shared datasets require metadata.

This helps users of the data—who may be

unfamiliar with the monitoring site—

understand the details behind the data.

Examples of metadata include (from

Williams, 1999):

• name of organization;

• name of the estuary;

• monitoring station identification

number;

• monitoring site location;

• site elevation;

• latitude, longitude;

• source describing how latitude and

longitude were determined; and

• date and time of collection.

Volunteer leaders—especially those who

want to share their data with government

and other organizations—should include

metadata on their field data sheets and

emphasize the importance to volunteers of

recording this information. 
5-16

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

use. They can serve as the project handbook

you give your volunteers. There are many

SOPs already available for sampling and

analytical procedures—check with your state

water quality agency or other volunteer

monitoring groups for pointers. Where

possible, adapt your procedures from existing

methods and modify them as needed to fit

your project objectives. Be sure to reference

and cite any existing methods and documents

that you use in your project.

You should append your SOPs to your

QAPP and refer to them throughout the QAPP

document. Your written plan can be elaborate

or simple, depending on your project goals.

Step 8: Solicit Feedback on Your Draft

SOPs and QAPP

Your next step is to get the draft reviewed

by people “in the know.” These include state

and EPA regional volunteer monitoring

coordinators and quality assurance officers

and any other potential data users. Ask for

feedback and suggestions from as many

sources as possible. Expect their reviews to

take up to two or three months (times will

vary). In addition, expect some resistance

from some reviewers who might be

overburdened with other duties. Don’t be

offended by this; instead, call back a

reasonable time after submitting your plan

and inquire if you should submit the draft

elsewhere for review.

While waiting for comments, you should try

out your procedures with volunteers on a trial

basis. Don’t plan to use the data at this early

stage; data users generally will not accept

your data until the QAPP has been approved

and accepted. Rather, use this opportunity to

find quirks in your plan.

Step 9: Revise Your QAPP and Submit It

for Final Approval

Based on the comments you receive, you

may have to revise your QAPP. This could

involve simply being more specific about

existing methods and quality control

procedures in the plan, or actually modifying

your procedures to meet agency requirements. 

Once you have revised or fine-tuned your

QAPP, submit it to the proper agency for

formal approval. If you are developing a

QAPP simply to document your methods and

are not working in cooperation with a state,

local, or federal agency, you do not need to

submit a QAPP for review and approval.

Step 10: Begin Your Monitoring Project

Once you’ve received formal approval of

your QAPP, your monitoring project can

begin. Follow the procedures described in

your QAPP to train volunteers and staff,

conduct sampling, analyze samples, compile

results, and develop any reports.

Step 11: Evaluate and Refine Your Project

over Time

As time goes on, you may decide to

improve on sampling techniques, site

selection, lab procedures, or any of the other

elements of your monitoring project design.

Project evaluation should occur during the

course of your project rather than after the

project or a sampling season is completed.

If you make any substantive changes to

your QAPP, document them and, if necessary,

seek approval from the appropriate agency. A

phone call to your quality assurance official

can help you determine if the changes require

a new QAPP. Also, always be prepared for

formal audits or QC inquiries from data users

during the course of your project.

Ongoing experience may require small

changes to the QAPP. These can be made

without having to rewrite the entire plan, as

long as the original reviewers approve the

changes. One helpful way to make changes

without rewriting the entire plan is to have the

pages individually dated; changes to the

document can then be made on a page-bypage basis. ■
5-17

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

A QAPP helps your group determine

responsibilities, training, methods, equipment

and other resources needed to ensure that data

quality is good enough to meet its intended

use. This section discusses the 24 elements of

a QAPP (Table 5-8), which can guide the

QAPP team as it determines whether all

necessary aspects are covered.

It is very likely that not all elements will

apply to your project, and other elements may

be required that are not addressed here. These

issues should be discussed with your QAPP

team and any group who will be approving

your QAPP. If EPA must approve your QAPP

and your project does not require all 24

elements, you should indicate in your QAPP

which elements you will not be including.

This will make review and approval of your

QAPP faster and easier.

Readers should refer to the document, The

Volunteer Monitor’s Guide to Quality

Assurance Project Plans (USEPA, 1996—see

“References and Further Reading” in this

chapter) for useful examples of developing a

QAPP. The document also includes a sample

QAPP form. 

Elements of a QAPP

Project Management (elements 1-9)

1. Title and Approval Page

2. Table of Contents

3. Distribution List

4. Project/Task Organization

5. Problem Identification/Background

6. Project/Task Description

7. Data Quality Objectives for Measurement Data

8. Training Requirements/Certification

9. Documentation and Records

Measurement/Data Acquisition (elements 10-19)

10. Sampling Process Design

11. Sampling Methods Requirements

12. Sample Handling and Custody Requirements

13. Analytical Methods Requirements

14. Quality Control Requirements

15. Instrument/Equipment Testing, Inspection, and Maintenance Requirements

16. Instrument Calibration and Frequency

17. Inspection/Acceptance Requirements for Supplies

18. Data Acquisition Requirements

19. Data Management

Assessment and Oversight (elements 20-21)

20. Assessments and Response Actions

21. Reports

Data Validation and Usability (elements 22-24)

22. Data Review, Validation, and Verification Requirements

23. Validation and Verification Methods

24. Reconciliation with Data Quality Objectives

Table 5-8. Elements of a QAPP (USEPA, 1996).
5-18

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Element 1: Title and Approval Page

Your title page should include the

following:

• title and date of the QAPP;

• names of the organizations involved in

the project; and

• names, titles, signatures, and document

signature dates of all appropriate

approving officials, such as project

manager, project QA officer, and if the

project is funded by EPA, the EPA

project manager and QA officer.

Element 2: Table of Contents

A table of contents should include section

headings with appropriate page numbers and a

list of figures and tables.

Element 3: Distribution List

List the individuals and organizations that

will receive a copy of your approved QAPP

and any subsequent revisions. Include

representatives of all groups involved in your

monitoring effort.

Element 4: Project/Task Organization

Identify all key personnel and organizations

that are involved in your program, including

data users. List their specific roles and responsibilities. In many monitoring projects,

one individual may have several responsibilities. An organizational chart is a good

way to graphically display the roles of key

players.

Element 5: Problem Identification/

Background

In a narrative, briefly state the problem your

monitoring project is designed to address.

Include any background information such as

previous studies that indicate why this project

is needed. Identify how your data will be used

and who will use it.

Element 6: Project/Task Description

In general terms, describe the work your

volunteers will perform and where it will take

place. Identify what kinds of samples will be

taken, what kinds of conditions they will

measure, which ones are critical, and which

are of secondary importance. Indicate how

you will evaluate your results—that is, how

you will be making sense out of what you

find. For example, you may be comparing

your water quality readings to state or EPA

standards, or comparing your submerged

aquatic vegetation (SAV) evaluations to stateestablished reference conditions or historical

information.

Include an overall project timetable that

outlines beginning and ending dates for the

entire project as well as for specific activities

within the project. The timetable should

include information about sampling

frequency, lab schedules, and reporting

cycles.

Element 7: Data Quality Objectives for

Measurement Data

Data Quality Objectives (DQOs) are the

quantitative and qualitative terms used to

describe how good your data must be to meet

the project’s objectives. DQOs for water

quality variables should address precision,

accuracy, representativeness, completeness,

comparability, and sensitivity (see “Basic

Concepts” in this chapter for a discussion of

these terms).

If possible, provide information on DQOs

in quantitative terms. Since it is important to

develop a QAPP prior to monitoring, it may

not be possible to include actual numbers for

some of the water quality measurement

variables within the first version of the

document. You will need, however, to discuss

your goals or objectives for data quality and

the methods you will use to make actual

determinations after monitoring has begun.

DQOs should be given for each parameter

you are measuring and in each “matrix” (i.e.,

substance you are sampling from, such as
5-19

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

water or sediment). A table is the easiest way

to present quantitative DQOs (see Table 5-9).

In some types of monitoring, particularly

macroinvertebrate monitoring and habitat

assessment, some data quality indicators cannot

be quantitatively expressed. In that case, you

can fulfill this requirement of the QAPP by citing and describing the method used and by providing as many of the data quality indicators as

possible (e.g., completeness, representativeness,

and comparability) in narrative form. 

DQOs should be set realistically. The volunteer program should closely examine its budget

when forming its DQOs. Decisions regarding

the ultimate objectives must always strike a balance between the needs of data users and the

fiscal restraints of the program (Figure 5-2). 

Element 8: Training Requirements/

Certification

Identify any specialized training or

certification requirements your volunteers will

need to successfully complete their tasks.

Discuss how you will provide such training,

who will conduct the training, and how you

will evaluate volunteer performance.

Element 9: Documentation and Records

Identify the field and laboratory information

and records you need for the project. These

records may include raw data, QC checks,

field data sheets, laboratory forms, and

voucher collections. Include information on

where and for how long records will be

maintained. Copies of all forms to be used in

the project should be attached to the QAPP.

Element 10: Sampling Process Design

Outline the experimental design of the

project including information on types of

samples required, sampling frequency,

sampling period (e.g., season), and how you

will select sample sites and identify them over

time. (A discussion on how to select

monitoring sites can be found in Chapter 6.)

Indicate whether any constraints such as

weather, seasonal variations, or site access

might affect scheduled activities and how you

will handle those constraints. Include site

safety plans. In place of extensive discussion,

you may cite the sections of your program’s

SOPs that detail the sampling design of the

project.

Parameter Method/Range Units Sensitivity Precision Accuracy

Temperature thermometer °C 0.5°C ±1.0°C ±0.2°C

-5.0° to 45°C

pH wide-range colorimetric standard pH units 0.5 units ±0.6 units ±0.4 units

field kit

3.0 to 10.0 units

Salinity hydrometer parts per thousand 0.1 ppt ±1.0 ppt ±0.82 ppt

(ppt)

Dissolved Winkler titration mg/l 0.2 mg/l ±0.9 mg/l ±0.3 mg/l

Oxygen 1 to 20 mg/l

Limit of Secchi disk meters 0.05m NA NA

Visibility

Table 5-9. Sample Data Quality Objectives (DQOs) for a volunteer estuary monitoring program. (Adapted from USEPA, 1990 and USEPA, 1996.)
5-20

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Element 11: Sampling Methods

Requirements

Describe your sampling methods. Include

information on parameters to be sampled,

how samples will be taken, equipment and

containers used, sample preservation methods,

and holding times (time between taking

samples and analyzing them). If samples are

composited (i.e., mixed), describe how this

will be done. Describe procedures for

decontamination and equipment cleaning.

Most of this information can be presented in a

table or you may also cite any SOPs that

contain this information.

Element 12: Sample Handling and

Custody Requirements

Sample handling procedures apply to

projects that bring samples from the field or

monitoring site to the lab for analysis,

identification, or storage. These samples should

be properly labeled in the field. At a minimum,

the sample identification label should include

sample location, sample number, date and time

of collection, sample type, sampler’s name, and

method used to preserve the sample.

Describe the procedures used to keep track

of samples that will be delivered or shipped to

a laboratory for analysis. Include any chainof-custody forms and written procedures that

field crews and lab personnel should follow

when collecting, transferring, storing,

analyzing, and disposing of samples and

associated waste materials.

Element 13: Analytical Methods

Requirements

List the methods and equipment needed for

the analysis of each parameter, either in the

field or in the lab. If your program uses

standard methods, cite these (see, for

example, APHA, 1998). If your program’s

methods differ from the standard or are not

readily available in a standard reference,

describe the analytical methods or cite and

attach the program’s SOPs.

Element 14: Quality Control Requirements

List the number and types of field and

laboratory quality control samples your

volunteers will take (see “Quality Control and

Assessment” earlier in this chapter). This

information can be presented in a table. If you

use an outside laboratory, cite or attach the

lab’s QA/QC plan.

What Is a Performance Based Measurement System (PBMS)?

Volunteer monitors may hear increased discussion about a fundamentally different approach to

environmental monitoring, known as a “performance based measurement system,” or PBMS.

Rather than requiring that a prescribed analytical method be used for a particular measurement, PBMS permits any method to be used provided that it demonstrates an ability to meet

required performance standards. In other words, PBMS conveys “what” needs to be

accomplished, but not prescriptively “how” to do it.

Under PBMS, the U.S. Environmental Protection Agency (EPA) would specify: 

• questions to be answered by monitoring;

• decisions to be supported by the data;

• the level of uncertainty acceptable for making decisions; and

• documentation to be generated to support this approach.

EPA believes that this approach will be more flexible and cost-effective for monitoring

organizations. Volunteer groups should check with their data users (e.g., state water quality

agencies) to determine acceptable performance based methods.
5-21

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

QC checks for biological monitoring

programs can be described in narrative form,

and, if appropriate, should discuss replicate

sample collection, cross checks by different

field crews, periodic sorting checks of lab

samples, and maintenance of voucher and

reference collections. Describe what actions

you will take if the QC samples reveal a

sampling or analytical problem.

Element 15: Instrument/Equipment

Testing, Inspection, and Maintenance

Requirements

Describe your plan for routine inspection

and preventive maintenance of field and lab

equipment facilities. Identify what equipment

will be routinely inspected, and what spare

parts and replacement equipment will be on

hand to keep field and lab operations running

smoothly. Include an equipment maintenance

schedule, if appropriate.

Element 16: Instrument Calibration and

Frequency

Identify how you will calibrate sampling

and analytical instruments. Include

information on how frequently instruments

will be calibrated, and the types of standards

or certified equipment that will be used to

calibrate sampling instruments. Indicate how

you will maintain calibration records and

ensure that records can be traced to each

instrument. Instrument calibration procedures

for biological monitoring programs should

include routine steps that ensure equipment is

clean and in good working order.

Element 17: Inspection and Acceptance

Requirements for Supplies

Describe how you determine if supplies,

such as sample bottles, nets, and reagents, are

adequate for your program’s needs.

Element 18: Data Acquisition

Requirements

Identify any types of data your project uses

that are not obtained through your monitoring

exercises. Examples of these types of data

include historical information, information

from topographical maps or aerial photos, or

reports from other monitoring groups. Discuss

any limits on the use of this data resulting

from uncertainty about its quality.

Element 19: Data Management

Trace the path of your data, from field

collection and lab analysis to data storage and

use. Discuss how you check for accuracy and

completeness of field and lab forms, and how

you minimize and correct errors in calculations, data entry to forms and databases, and

report writing. Provide examples of forms and

checklists. Identify the computer hardware

and software you use to manage your data.

Element 20: Assessments and Response

Actions

Discuss how you evaluate field, lab, and

data management activities, organizations

(such as contract labs), and individuals in the

course of your project. These can include

evaluations of volunteer performance (e.g.,

through field visits by staff or in laboratory

refresher sessions); audits of systems (e.g.,

equipment and analytical procedures); and

audits of data quality (e.g., comparing actual

data results with project quality objectives).

Include information on how your project

will correct any problems identified through

these assessments. Corrective actions might

include calibrating equipment more

frequently, increasing the number of regularly

scheduled training sessions, or rescheduling

field or lab activities.
5-22

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Element 21: Reports

Identify the frequency, content, and

distribution of reports to data users, sponsors,

and partnership organizations that detail

project status, results of internal assessments

and audits, and how QA problems have been

resolved.

Element 22: Data Review, Validation, and

Verification Requirements

State how you review data and make

decisions about accepting, rejecting, or

qualifying the data. All that is needed here is

a brief statement of what will be done and by

whom.

Element 23: Validation and Verification

Methods

Describe the procedures you use to validate

and verify data. This can include, for

example, comparing computer entries to field

data sheets; looking for data gaps; analyzing

quality control data such as chain of custody

information, spikes, and equipment

calibrations; checking calculations; examining

raw data for outliers or nonsensical readings;

and reviewing graphs, tables, and charts.

Include a description of how detected errors

will be corrected and how results will be

conveyed to data users.

Element 24: Reconciliation with Data

Quality Objectives

Once the data results are compiled, describe

the process for determining whether the data

meet project objectives. This should include

calculating and comparing the project’s actual

data quality indicators (precision, accuracy,

completeness, representativeness, and

comparability) to those you specified at the

start of the project and describing what will

be done if they are not the same. Actions

might include discarding data, setting limits

on the use of the data, or revising the project’s

data quality objectives. ■

References and Further Reading

Much of this chapter was excerpted and adapted from:

U.S. Environmental Protection Agency (USEPA). 1996. The Volunteer Monitor’s Guide to

Quality Assurance Project Plans. EPA 841-B-96-003. September. Web site:

http://www.epa.gov/OWOW/monitoring/volunteer/qappcovr.htm

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A

Methods Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

Other references:

Alliance for the Chesapeake Bay. 1987. Quality Assurance Project Plan for the Citizen

Monitoring Project. Chesapeake Bay Citizen Monitoring Program. Baltimore, MD. 94 pp.

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L.S. Clesceri, A.E. Greenberg, A.D. Eaton (eds). Washington, DC.
5-23

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning

Ely, E. (ed.) 1992. The Volunteer Monitor. “Special Topic: Building Credibility.” 

4(2). 24 pp.

Maine Department of Environmental Protection (DEP). 1996. A Citizen’s Guide to Coastal

Watershed Surveys. 78 pp.

Mattson, M. 1992. “The Basics of Quality Control.” The Volunteer Monitor 4(2): 6-8.

U.S. Environmental Protection Agency (USEPA). 1987. Data Quality Objectives Workshop,

Washington, DC.

U.S. Environmental Protection Agency (USEPA). 1988. Guide for the Preparation of Quality

Assurance Project Plans for the National Estuary Program. EPA 556/2-88-001. Washington,

DC. 31 pp.

U.S. Environmental Protection Agency (USEPA). 1990. Volunteer Water Monitoring: A Guide

for State Managers. EPA 440/4-90-010. August. Office of Water, Washington, DC. 78 pp.

U.S. Environmental Protection Agency (USEPA). 1995. Bibliography of Methods for Marine

and Estuarine Monitoring. EPA 842-B-95-002. April. Office of Water, Washington, DC.

Williams, K. F. 1999. “Quality Assurance Procedures.” In: Meeting Notes—U.S. Environmental

Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer

Estuary Monitoring: Wave of the Future. Astoria, OR: May 19-21, 1999.

Web sites:

Metadata Information: 

Federal Geographic Data Committee: http://www.fgdc.gov/metadata/

U.S. Geological Survey: http://geology.usgs.gov/tools/metadata/tools/doc/faq.html#1.1
5-24

Volunteer Estuary Monitoring: A Methods Manual

Chapter 5: Quality Assurance Project Planning
Chapter 6 Sampling Considerations

In the very early stages of developing any volunteer estuary monitoring program,

four important decisions must be made: what environmental parameters to

monitor, how the parameters will be measured, where monitoring sites will be

located, and when monitoring will occur.
Photos (l to r): Tillamook Bay National Estuary Project and Battelle Marine Sciences Lab, K. Register, R. Ohrel, R. Ohrel
6-1

Volunteer Estuary Monitoring: A Methods Manual

Chapter 6: Sampling Considerations

In the very early stages of developing any volunteer estuary monitoring

program, four important decisions must be made. Program leaders, with input

from their volunteers, must decide what environmental parameters they will

monitor, how the parameters will be measured, where monitoring sites will be

located, and when monitoring will occur.

This chapter discusses some considerations that should be taken into account

when making these decisions.

Overview
6-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 6: Sampling Considerations

Previous chapters laid the

groundwork for developing

and operating a volunteer

estuary monitoring program.

Discussions focused on the

need for volunteer programs

to understand why it is

necessary to collect data,

how the data will be used,

and who will use it.

Involving potential data

users in program

development is essential.

There are many additional

components to the development of an overall

monitoring program and its quality assurance

project plan (QAPP). Most revolve around

four fundamental questions:

• What parameters will the volunteer program monitor?

• How will the selected parameters be

monitored?

• Where will monitoring sites be located?

• When will monitoring occur?

While the questions may seem basic

enough, they can hardly be overlooked or

brushed aside. Clear and concise answers to

these simple yet focused questions will form

the backbone of your monitoring program,

providing the foundation upon which the

program will rest.

Over time, it will be valuable to reevaluate

your answers to ensure that the goals and

objectives of the program are still being met.

Such evaluations may reveal a need for

program adjustments.

What to Monitor? Selecting Sampling

Parameters

What aspects of the estuary should your

volunteer program monitor? There are many

options from which to choose, but ultimately

the parameters should be selected to help

characterize the health of your estuary. By

assessing the problems—and potential

problems—facing the estuary, it should

become clear which parameters will be most

important to monitor. Of course, the costs

(time and money) associated with monitoring

will factor into your decision. 

There are several common water quality

parameters that volunteer programs measure

(see Ely and Hamingson, 1998). These

include:

• water temperature;

• turbidity or transparency;

• dissolved oxygen;

• pH;

• salinity; and 

• nutrients.

As techniques are mastered and monitoring

skills improve, many volunteer groups go on

to include additional parameters to their

monitoring repertoire, including:

• fecal coliform and other indicator 

bacteria;

• chlorophyll;

• sulfates;

• pesticides;

• metals;

• changes in water color following storm

events;

• effects of erosion and sediment control

measures;

• habitat conditions and availability;

• macroinvertebrates;

• condition and abundance of fish and

birds; and

• phytoplankton, submerged aquatic vegetation (SAV) and shoreline plants.

Four Critical Questions

Many field test kits require the monitor to

compare the colors of a prepared water 

sample with a standard (photo by K. Register).
6-3

Volunteer Estuary Monitoring: A Methods Manual

Chapter 6: Sampling Considerations

Helpful Hint

When deciding what water quality variables

to monitor, consider the needs of your data

users. They can help you select the variables

that most effectively detect potential

problems in the estuary. In addition to your

data users, also consult with the following:

• state, federal, and regional environmental quality agencies;

• municipal governments;

• county planning offices;

• wastewater treatment plants;

• local nonprofit environmental groups;

• university and college environmental

departments (e.g., environmental science, oceanography, civil engineering,

hydrology, biology); and

• middle and high school teachers.

How to Monitor? Selecting Monitoring

Methods and Equipment

An important question for any monitoring

program concerns monitoring methods and

equipment. As you will see in later chapters,

there are usually two or more ways to monitor

any water quality parameter. 

Your selection of methods and equipment

will be based partly on data accuracy requirements and cost. For a state water quality agency

to accept volunteer-generated data, for example,

the data must be collected using state-approved

methods and equipment. If the purpose of the

monitoring is to “screen” for potential problems, you may purchase less expensive and perhaps less accurate or precise equipment. 

Electronic meters (powered by batteries) are

available to measure many different water quality parameters, including pH, dissolved oxygen,

conductivity, salinity, temperature, total dissolved solids, and biochemical oxygen demand.

Many meters will test for two or more of these

parameters. Meters can provide quick and accurate data, but they require frequent calibration

and regular maintenance to ensure proper functioning. They can also be expensive, ranging

from $300 to $5000, depending on the number

of functions, accuracy, range, and resolution of

the instrument. Nevertheless, meters may prove

cost-effective, especially when a large number

of samples need to be analyzed.

Field test kits measure many of the same

water quality parameters as meters and tend to

be much less expensive, but pollutant detection

levels can be unacceptable to some data users.

Again, part of the decision to use meters or

field kits will depend on the quality of data that

your program is trying to achieve. In some

states, the data from volunteers using field kits

will be accepted, while in other states, the data

will be considered valuable only as a “screen”

for potential problems.

Some Tips on Kits

Suppose you intend to use inexpensive field

kits that rely on a visual color comparison

using a “color wheel” or “color comparator.”

How would you go about shopping for the

most suitable kits? Here are a few

suggestions:

• Look for reagents that produce a blue or

green color; the human eye is better at

perceiving the density of blue or green.

• Look for less toxic reagents (e.g., salicylate versus Nessler for ammonia, zinc

rather than cadmium for nitrate). 

• Look for kits that report the lowest possible concentration range, relying on the

option of diluting the sample if the concentration is too high (make sure you

have the equipment for making dilutions—a small syringe without needle,

distilled water, and a dedicated jar). 

• Look for reagents in liquid form rather

than powder—it is often tedious to

wrestle with powder packets, especially

with wind that may blow and scatter

the powder. 

(Excerpted and adapted from Katznelson, 1997.)
6-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 6: Sampling Considerations

Where to Sample? Selecting Monitoring

Locations

Volunteer program leaders must determine

the geographic location where monitoring

efforts will provide the most useful

information. After monitoring sites are

selected, a decision must be made about

where in the water column volunteers will

collect their samples.

Picking Monitoring Sites

Selecting representative sampling sites is

one of the most important elements in setting

up a monitoring effort. In any type of water

quality monitoring, basic information about

the area of interest is essential for the program

manager to consider before selecting

monitoring sites. Several things to consider

are listed in the box below.

Considerations for Selecting Monitoring Sites

Background Information

• Obtain a map of the watershed with all areas that drain into the estuary identified and a bathymetric map of

the estuary showing depth information.

• Gather reports and/or data that supply general information on the estuary.

• Check with your state water quality agency and other monitoring groups to learn their monitoring site

locations. Monitoring at the same sites monitored by other groups can help provide trend data; monitoring

different sites can improve coverage of the entire estuary.

• Collect information on adjoining estuaries if there are plans to conduct data comparisons.

• Compile data on current and past activities in the basin that could affect pollutant levels (e.g., locations of

wastewater treatment plants, areas of urban or agricultural runoff, new development sites).

• Investigate sites in areas of known or suspected pollution.

Decision-Making

• Determine whether there is a real need for data to be collected from the area, thereby ensuring the immediate use

of data collected.

• Consider whether you have a sufficient pool of volunteers to monitor the site in the manner and time required.

• Consider sites where there may be little or no data (e.g., areas near land targeted to be developed) to establish

baseline conditions.

• Consider how long data will need to be collected at the site in order to be useful. For example, several years of

data collection may be necessary to make justifiable conclusions about water quality trends.

Verification

• Confirm that you will have safe, physical, and legal access to the site(s).

• If the monitoring effort requires the collection of water samples, verify that the site is underwater at all times,

including low tide. 

• Ensure that sampling sites are representative of the estuary and its watershed, if your goal is to assess overall

estuary health (e.g., a site immediately downstream of a bridge is not likely to be representative of overall estuary

conditions).

• Confirm that volunteers can precisely relocate the site.

(Adapted from USEPA, 1990, and Stancioff, 1996.)
6-5

Volunteer Estuary Monitoring: A Methods Manual

Chapter 6: Sampling Considerations

Site location will depend a great deal on the

purpose of data collection. If, for example, the

program is attempting to pinpoint trouble

spots in the estuary, the manager should

cluster monitoring sites where point and

nonpoint pollution sources enter the water. To

help ensure the data’s scientific validity,

volunteers should monitor sample locations

both upstream and downstream from the

pollutant inflow point, as well as at the point

of entry, to provide comparative data. 

Some programs may wish to obtain baseline

data that, over several years, will reveal water

quality trends. Rather than concentrating on a

few critical sites, this type of program should

choose a sufficient number of sites scattered

throughout the estuary or in the area of

interest that will paint a representative picture

of water quality status over time. 

Deciding Where to Sample in the Water

Column

Monitors must consider that water quality

parameters are always changing. At any given

time, conditions at the surface may not be the

same as those at the bottom. For most citizen

monitoring programs and most water quality

parameters, however, samples taken from the

estuary’s surface will suffice. These samples

will provide a reasonably accurate indication

of water quality in the vicinity of the

sampling site. For more sophisticated studies

in which water quality parameters throughout

the water column are of interest, volunteers

may need to collect samples using a standard

water sampler at precise depths. 

The stratification of the estuary may also

influence where samples are taken in the

water column. For instance, a well-stratified

estuary may require surface, intermediate, and

bottom water samples or a complete profile to

fully characterize the status of different water

quality variables in its waters. A reasonably

well-mixed estuary, however, or one in which

the monitoring sites are located only in

shallow waters (where stratification often

breaks down) may require only a single

surface sample at each site.

While tidal range (the difference between

high and low tides) is negligible in some

estuaries, programs studying areas with large

swings in tides will have to consider this

effect. Tides strong enough to cause mixing

may weaken the stratification in the estuary.

This effect is particularly apparent during

spring tides (the highest tides of the month).

By mixing the upper and lower layers, for

example, the tides allow nutrients trapped in

bottom waters to mix upward and oxygen

from the surface to move down. 

When to Sample? 

Selecting the Right Time

The timing of most sampling efforts will

depend largely on the goals of the monitoring

program, accessibility of the site, weather,

number of monitors, and the water quality

variables to be measured. The time of day and

season can significantly affect your results. In

addition, the maximum holding time for each

sample and the sampling frequency necessary

to get the right information can influence

when samples will need to be collected

(Dates, 1992).

Time of Day

Sampling results can fluctuate dramatically,

depending on the time of day that samples are

collected. For example, during the day aquatic

plants utilize sunlight for photosynthesis,

releasing oxygen as a byproduct. At night, the

plants respire, consuming oxygen. As a result,

dissolved oxygen levels can rise and fall

significantly, especially in areas with dense

aquatic vegetation. Under these

circumstances, oxygen concentrations are

lowest at sunrise and highest in the afternoon. 

The time of day will also influence where

many organisms will be found in the water

column. Zooplankton, for example, migrate

from deeper water to the surface at night to

feed, while many fish species travel daily

throughout the water column in search of

food. 

The time of day has other impacts on

monitoring. A common tool for measuring
6-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 6: Sampling Considerations

water clarity is the Secchi disk. One condition

for its optimal use is that the disk be used

when the sun is directly overhead. (The disk

can be used at other times during the day, but

this would result in less than optimal results;

see Chapter 15). To comply with this

condition means that there is a small window

of opportunity for which monitoring

conditions are ideal. 

Because of these daily considerations, it is

often helpful to select consistent sampling

times for many water quality parameters.

However, ideal sampling times may also

depend on tides, which could expose nothing

but mud where there had been water only a

few hours earlier. Tidal stages vary from day

to day.

Time of Year

Environmental conditions change with the

seasons, and monitoring results can reflect

those variations. For example, nutrient and

pesticide concentrations in estuaries vary

considerably from season to season. More

runoff enters the estuary during wet weather

periods, delivering pollutants and fresh water.

Consequently, pollution concentrations can be

higher and salinity lower at these times. When

runoff occurs, higher estuarine concentrations

correspond to times of the year when

fertilizers and pesticides are most commonly

applied on land (USGS, 1999).

On the other hand, dry weather periods

mean less runoff to the estuary. Higher

salinity and lower pollutant levels may mark

such dry periods. The same observation may

be made in colder climates during the winter,

when snow remains on land and the spring

thaw is months away.

The seasons have a profound influence on

several other water quality measures,

particularly dissolved oxygen. For example: 

• cold water retains dissolved oxygen better than warmer water; 

• increased plant activity in the warmer

months has a strong influence on daily

oxygen concentrations;

• vertical temperature gradients in the

estuary—usually greater during the

summer months—hinder oxygen 

diffusion; and 

• seasonal storms help mix estuarine

waters.

Seasonal sampling may also be influenced

by program objectives. If your program is

interested in determining whether the estuary

is safe for swimming, for example, it is best

to sample when people are most likely to be

in the water. For this purpose, it is

unnecessary in most places to sample during

the winter.

Finally, there is the practicality issue.

Seasons may influence the level of volunteer

participation. Will enough volunteers be

willing to go out in freezing weather or under

a scorching sun to collect samples? 

Holding Time

Consider the maximum duration that a

sample can be held before it is tested. Many

bacteria samples must be chilled and sent to a

laboratory for testing within six hours.

Because of the stringent holding time

requirements, sampling during weekends and

evenings—when most laboratories are

closed—may not be a good idea for some

water quality measures.

Frequency

Like most issues of timing, sampling

frequency usually depends on the goals of the

monitoring effort. For example, if you are

monitoring to detect pollution from point

sources, very frequent sampling—daily or

even hourly—is usually necessary. On the

other hand, some biological parameters,

which indicate estuarine conditions over long

periods of time, need to be sampled only a

couple of times each year (usually the spring

and fall). 

Sampling frequency may also be

determined based on atmospheric or other

events. It is often useful to have volunteers
6-7

Volunteer Estuary Monitoring: A Methods Manual

Chapter 6: Sampling Considerations

available to collect data during or after large

storms as long as the program manager deems

it safe to sample. Such data is often

invaluable to state managers who may be

unable to mobilize forces quickly enough to

capture such events. Storm data gives a

snapshot of how severe wind and precipitation

affect the status of water quality variables in

the water. The occurrence of extraordinary

events, such as fish kills or “crab jubilees”

(phenomena characterized by crabs crawling

onto the land because of low oxygen

concentrations in the water), can also trigger

additional monitoring efforts to determine the

cause of the events. ■

Dates, G. 1992. “Study Design: The Foundation of Credibility.” The Volunteer Monitor

4(2): 1, 13-15.

Ely, E. and E. Hamingson. 1998. National Directory of Volunteer Environmental Monitoring

Programs. 5th ed. U.S. Environmental Protection Agency, Office of Wetland, Oceans, and

Watersheds. EPA-841-B-98-009. Web site: http://yosemite.epa.gov/water/volmon.nsf.

Stancioff, E. 1996. Clean Water: A Guide to Water Quality Monitoring for Volunteer Monitors of

Coastal Waters. Maine/New Hampshire Sea Grant Marine Advisory Program and University

of Maine Cooperative Extension. Orono, ME. 73 pp.

U.S. Environmental Protection Agency (USEPA). 1990. Volunteer Water Monitoring: A Guide

for State Managers. EPA 440/4-90-010. August. Office of Water, Washington, DC. 78 pp.

U.S. Geological Survey (USGS). 1999. The Quality of Our Nation’s Waters—Nutrients and

Pesticides. USGS Circular 1225. 82 pp.

References and Further Reading
6-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 6: Sampling Considerations
Chapter 7 In the Field

Being in the estuarine environment has great appeal for many volunteers. The key

for any program leader is to maintain volunteer interest while ensuring the quality

of data. To meet these goals, the program leader must recognize that several

elements go into the collection of estuary data. Failure to consider these elements

can cause problems for volunteers and program managers.
Photos (l to r): Weeks Bay Watershed Project, U.S. Environmental Protection Agency, E. Ely, K. Register
7-1

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

Being in the estuarine environment has great appeal for many volunteers. The

key for any program leader is to maintain volunteer interest while ensuring the

quality of data. To meet these goals, the program leader must recognize that

several elements go into the collection of estuary data. Failure to consider these

elements can cause problems for volunteers and program managers.

Previous chapters discussed planning a volunteer monitoring program,

establishing a quality assurance project plan, and general sampling considerations.

This chapter reviews several topics applicable when volunteers travel into the

estuary to collect and analyze samples. It includes discussions of safety, supplies

and equipment, locating the sampling site, making observations about the site,

collecting data, and completing the data collection form.

Overview
7-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

As discussed in Chapter 4, volunteers have

different reasons for getting involved with an

estuary monitoring program. One common

motive is the opportunity to be outside, on the

water, helping the estuary. Many volunteers

look forward to going, as scientists say, “into

the field” to collect and analyze water

samples. For them, being in the field is an

enjoyable experience.

While being in the field is more often than

not an entertaining experience for all

involved, volunteer leaders need to be aware

of several potential pitfalls. Sampling errors

can compromise data quality. Disappointed or

angry volunteers can return, after hours of

mucking around, with no data because they

discovered too late that their equipment was

not operating properly. Data interpretation

may be hampered because volunteers fail to

complete data forms properly. Volunteer

injuries, while uncommon, must always be in

the back of every leader’s mind.

With proper planning and training, the

monitoring leader can avoid these problems.

A bit of forethought before sending volunteers

to monitoring sites can ensure volunteer

safety, data quality, and fun in the field. ■

Fun in the Field

Preliminary Steps for Field Sampling

The following steps generally apply when monitoring most estuary water quality variables. Elaboration on these

steps is provided throughout this chapter. These are not the only necessary steps, however. Additional steps should

be taken for each water quality parameter. Refer to each respective chapter for details. 

STEP 1: Prepare for the field 

Before proceeding to the monitoring site, the volunteer should confirm sampling date and time, understand safety

precautions, check weather conditions and verify directions to the monitoring site.

STEP 2: Check equipment 

The volunteer should also ensure that all necessary personal gear and sampling equipment are present and in working

order. Results may be inaccurate if the volunteer has to improvise because a sampling device or chemical bottle has

been left behind. 

STEP 3: Confirm proper sampling location

The volunteer should have specific directions for locating a sampling site. If unsure whether he or she is in the correct

spot, the volunteer should record a detailed description of where the sample was taken so that it can be compared to the

intended site later.

STEP 4: Record preliminary observations and field measurements 

The volunteer should record general field observations and measurements (e.g., potential pollution sources, indicators of

pollution, presence and apparent health of wild and domestic animals, water color, debris or oil, algal blooms, air temperature, weather conditions, etc.) once at the site. This information is valuable when it comes time to interpret your results.

Record any condition or situation that seems unusual. Descriptive notes should be as detailed as possible.
7-3

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

Chapter 4 detailed volunteer training,

emphasizing safety, proper monitoring

techniques, and quality assurance/quality

control procedures. No volunteer should begin

monitoring until properly trained.

Before heading out to sample for the first

time, the volunteer should select a sampling

timetable that fits into his or her personal

schedule. Adherence to the sampling schedule

is ideal, but program managers should

recognize that occasionally scheduled

sampling days and times will be missed due

to weather, illness, holidays, vacations, etc. If

possible, a makeup date should be arranged

within two days on either side of the original

date or a trained backup volunteer should

substitute for an unavailable volunteer.

The volunteer should confirm the sampling

date and time with the program manager and

laboratory (if samples are being sent for lab

analysis) each time before going out to collect

samples. This is especially true if the samples

need to be analyzed in a laboratory within a

particular timeframe.

The volunteer, in collaboration with the

program manager, should also characterize the

collection site with a written description, map,

and accompanying photograph. This

information serves as an initial status report

with which to compare any future changes of

the site. Use a global positioning system unit,

nautical map, or topographic map to

determine the latitude and longitude of the

site. Maps and photographs may be available

for your area (see Appendix C). ■

Before Leaving Home

Safety Considerations

Safety is one of the most critical

considerations for a volunteer monitoring

program and can never be overemphasized.

All volunteers should be trained in safety

procedures and should carry with them a set

of safety instructions and the phone number

of their program coordinator or team leader. 

The following are some basic commonsense

safety rules for volunteers: 

• Develop a safety plan. Find out the

location and telephone number of the

nearest telephone and write it down, or

have a cellular phone available. Locate

the nearest medical center and write

down directions for guiding emergency

personnel from the center to your

site(s). Have each member of the

sampling team complete a medical form

that includes emergency contacts,

insurance information, and relevant

health information such as allergies,

diabetes, epilepsy, etc.

• Listen to weather reports. Never go

sampling if severe weather or high

waves are predicted or if a storm occurs

while at the site. Training should

include information on the appropriate

circumstances for both proceeding with

and waiving data collection. If

volunteers elect to go out in poor

conditions, they should be aware of the

risks and always take proper safety gear

(particularly if proceeding by boat). No

one should go out on the water during

thunderstorms or high wave conditions.

• Always monitor with at least one

partner (teams of three or four are best).

Let someone know where you will be,

when you plan to return, and what to do

if you don’t return at the designated

time.
7-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

• Have a first aid kit handy (see box, page

7-5). Know any important medical

health conditions of volunteers (e.g.,

heart conditions or allergic reactions to

bee stings). It is best if at least one team

member has current first aid/CPR

training.

• Dress properly. In cold weather, bring

layered clothing, gloves, and boots. In

warm weather, dress to avoid sunburn,

insects, jellyfish, and brambles. Always

bring goggles and latex gloves (or some

alternative gloves for those allergic to

latex). Wear hunter’s orange during

hunting season.

• Bring water and snacks.

• If you drive, park in a safe location. Be

sure your car doesn’t pose a hazard to

other drivers and that you don’t block

traffic.

• Put your wallet and keys in a safe place,

such as a floatable, watertight bag that

can be kept in a pouch strapped to your

waist. 

• Never cross private property without the

permission of the landowner. A better

option, depending on the project’s

objectives, might be to sample at public

access points (e.g., public parks). Take

along a card identifying you as a

volunteer monitor.

• Watch for irate dogs, farm animals, and

wildlife (particularly snakes, ticks,

hornets, and wasps). Know what to do if

you get bitten or stung.

• Watch for poison ivy, poison oak,

sumac, and other types of vegetation in

your area that can cause rashes and

irritation.

• Do not walk on unstable riverbanks.

Disturbing these banks can accelerate

erosion and might prove dangerous if

the bank collapses. Do not disturb

vegetation on the banks.

• Be very careful when walking in the

estuary itself. Rocky-bottom areas can

be very slippery and soft-bottom areas

may prove treacherous in areas where

mud, silt, or sand have accumulated in

sinkholes. Your partner(s) should wait

on dry land, ready to assist you if you

fall. Wear waders and rubber gloves at

sites suspected of having significant

pollution problems.

• Never wade in swift or high water.

• Confirm that you are at the proper site

by checking maps, site descriptions,

directions, or a global positioning

system.

• Do not monitor if the site is posted as

unsafe for body contact. If the water

appears to be severely polluted, contact

your program coordinator.

• Pay attention to the tidal stage. Don’t

get trapped by rising or falling tides.

• If you are sampling from a bridge, be

wary of passing traffic. Wear bright

orange safety vests and hats and set out

orange traffic cones. Never lean over

bridge rails unless you are firmly

anchored to the ground or the bridge

with good hand/foot holds.

• Wash your hands with antibacterial soap

after monitoring. Eat nothing until you

have washed your hands.

• If you are using a boat, ensure that

hulls, engines, equipment, and trailers

are inspected and in good working

order.

• If at any time you feel uncomfortable

about the condition of the monitoring

site or your surroundings,

immediately stop monitoring and

leave the site. Your safety is more

important than the data!
7-5

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

When using chemicals:

• Know your equipment, sampling

instructions, and procedures before

going out into the field. Prepare labels

and clean equipment before you get

started.

• Keep the sampling equipment clean

before and after each use. 

• Keep all equipment and chemicals away

from small children and animals. Many

of the chemicals used in monitoring are

poisonous. Tape the phone number of

the local poison control center to your

sampling kit.

• Avoid contact between chemical

reagents and skin, eye, nose, and mouth.

Never use your fingers to stopper a

bottle (e.g., when you are shaking a

solution). Wear safety goggles and

gloves when performing any chemical

test or handling preservatives. 

• Know how to use and store chemicals.

Do not expose chemicals or equipment

to temperature extremes or long-term

direct sunlight (see “Getting the Most

Out of Reagents,” page 7-6).

• Any work surface should be kept clean

of chemicals and sponged with clean

water after the test is complete.

• Know chemical cleanup and disposal

procedures. Wipe up all spills when they

occur. Return all unused chemicals to

your program coordinator for safe

disposal. Close all containers tightly

after use. Do not put the cap of one

reagent onto the bottle of another.

Dispose of waste materials and spent

chemicals properly (see box, page 7-8).

• When working with bacteria samples,

wash your hands between samples and

when you are finished with testing.

Avoid contact with bacterial colonies

after they have been incubated

(Stancioff, 1996). ■

First Aid

At a minimum, a first aid kit should

contain the following items:

• Telephone numbers of emergency

personnel (e.g., police, ambulance

service)

• First aid manual which outlines

diagnosis and treatment procedures

• Antibacterial or alcohol wipes

• First aid cream or ointment

• Acetaminophen for relieving pain and

reducing fever

• Several band-aids

• Several gauze pads 3 or 4 inches square

• 2-inch roll of gauze bandage

• Triangular bandage

• Large compress bandage

• 3-inch wide elastic bandage

• Needle for removing splinters

• Tweezers for removing ticks

• Single-edged razor blade

• Snakebite kit

• Doctor-prescribed antihistamine of

participant who is allergic to bee stings

Be sure to carry emergency telephone

numbers and medical information for

everyone participating in field work

(including the leader) in case of

emergency.

(Excerpted and adapted from USEPA, 1997.)
7-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

Getting the Most Out of Reagents

Most volunteer monitoring programs use chemicals called reagents to help analyze water

samples. Because the reagents are chemically reactive, they can easily degrade. Test

reagents are also very susceptible to contamination under field conditions. 

Replacing degraded reagents results in additional expense for the monitoring program. If

bad reagents are not discovered in time, their use can also lead to erroneous water quality

measurements and disappointed volunteers whose hard work in the field is wasted. It is

therefore wise—financially and programmatically—to check reagent quality and extend

their useful life whenever possible.

Reagent Enemies

Temperature 

In general, the speed of a chemical reaction doubles with every 10°C increase in

temperature. Since reagent decomposition occurs by means of chemical reactions, high

temperatures will speed decomposition. 

Sunlight 

Many reagents will decompose when exposed to direct sunlight. Reagents containing

silver—commonly found in kits that use a titration method to test chloride or salinity—

are especially sensitive to sunlight and will turn black when decomposition occurs due to

sunlight exposure. This reagent is supplied in an amber glass, amber plastic, or other

opaque plastic container to protect it from sunlight. 

Air

Evaporation can concentrate reagents, a condition which is especially critical for a titrant.

Many reagents can also react chemically with oxygen or carbon dioxide in the air. 

Contamination 

Any foreign material introduced into a reagent bottle can cause test results to be in error.

Mold or algae can grow in starch reagents. Other common sources of contamination are

inadequate cleaning of equipment that is used to analyze more than one sample and

failure to use a dedicated dropper for each reagent. 

(continued)
7-7

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

Recognizing Bad Reagents 

One of the easiest ways to tell if a reagent has gone bad is by its appearance. Note the

reagent’s color when you first receive it. Over time, look for any changes in color or

clarity, or for formation of solids (e.g., a crust on the lip of the bottle, floating particles,

or solids settled at the bottom). 

If you suspect that a reagent has gone bad, you can test it by using a standard (a solution

of known pollutant concentration). Standards can be purchased from test kit

manufacturers or other chemical companies, or obtained from cooperative laboratories.

Most reagents will also have expiration dates printed on their containers.

You can also test your reagents by checking the suspect test kit against another kit that

has fresh reagents, or by cross-checking the kit against another method, such as a meter. 

Preventing Degradation

There are many steps you can take in the field to get the most use out of reagents:

• Keep reagent bottles inside test kit during storage.

• Store kits away from heat and sunlight (this includes car trunks!).

• Minimize the amount of reagent exposure to heat and sunlight during testing.

• Do not leave reagent containers open any longer than necessary when performing

tests.

• Be sure to place sunlight-sensitive reagents in opaque bottles when replacing or

refilling them.

• Keep reagent bottles tightly capped.

• Use dedicated droppers and dedicated equipment whenever possible. 

• Always bring a container to the field for washing equipment between tests.

• Keep reagents in a refrigerator that is not used to store food.

Of course, check expiration dates and replace reagents before they expire.

(Excerpted from McAninch, 1997.)

(Getting the Most . . .continued)
7-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

Dealing with Waste

Waste Liquids:

Many water quality monitoring kits produce waste liquids that you cannot pour into the

estuary. Read the “Material Safety Data Sheet” that comes with your monitoring equipment

for specific disposal procedures. Here is one method used to dispose of waste liquids: 

• Pour all waste liquids into a separate container, such as a bottle or jug with a screw cap.

Beverage containers should not be used for this purpose, since the contents could be

mistaken for a beverage. Containers into which liquid wastes are poured should be

clearly labeled with appropriate warnings. It is usually acceptable to mix the waste 

from all your field tests, but confirm this by reading the “Material Safety Data Sheet”

that comes with the monitoring equipment.

• Take the waste container home (don’t dump it outside).

• At home, add kitty litter to the container, cap it tightly, and put it out with the trash.

Some manufacturers’ Material Safety Data Sheets will tell monitors to dilute waste liquids

and pour them down the drain if the monitors’ homes are served by centralized wastewater

treatment systems. It is recommended that volunteer leaders contact their local wastewater

management agency to get exact instructions. It is important to tell the wastewater

management agency the names of each chemical used. Never put the waste liquids down the 

drain if you have a septic system, and never dispose of mercury from a broken thermometer

by pouring it down any drain. Many volunteer programs avoid this potential problem by using

alcohol thermometers.

Bacteria Cultures: 

After counting the colonies that have grown in petri dishes, two methods to safely destroy the

bacteria cultures are:

Autoclave

Place all petri dishes in a container in an autoclave. Heat for 15 to 18 minutes at 121o

C and at

a pressure of 15 pounds per square inch. Throw away the petri dishes.

Bleach

Disinfection with bleach should be done in a well-ventilated area, since it can react with

organic matter to produce toxic and irritating fumes. Pour a 10-25 percent bleach solution

into each petri dish. Let the petri dishes stand overnight. Place all petri dishes in a sealed

plastic bag and throw away. 
7-9

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

Much of the equipment a volunteer will need

in the field is easily obtained from either hardware stores or scientific supply houses. Other

equipment can be found around the house. In

either case, the volunteer program should clearly specify the equipment its volunteers will

need and where it should be obtained.

Listed below are some basic supplies appropriate for any volunteer field activity. Much

of this equipment is optional but will enhance

the volunteers’ safety and effectiveness. 

Safety and Health Supplies

• rubber gloves to guard against

contamination (warning: some people

are allergic to latex; ask volunteers if

they are allergic);

• eye protection;

• insect repellent;

• sunblock;

• small first aid kit (see box, page 7-5);

• flashlight and extra batteries; 

• whistle to summon help in emergencies;

• cellular phone;

• refreshments and drinking water;

• personal identification (e.g., driver’s

license);

• compass or Global Positioning System

receiver; and

• information sheet with safety

instructions, site location information,

and numbers to call in emergencies

(heavily laminated or printed on

waterproof “write in rain” paper, if

possible).

Clothing

• boots or waders;

• hat;

• foul/cold weather gear;

• extra pair of socks;

• sweater or other warm clothing;

• all-weather footwear; and

• bright-colored snag- and thorn-resistant

clothes (long sleeves and pants are best).

Sampling Gear

• sampling equipment—properly calibrated

and checked for accuracy—appropriate

for the parameter(s) being measured (may

include meters, test kits, etc.);

• water sampler (see “How to Collect

Samples” in this chapter);

• sample containers;

• sufficient supply of reagents;

• instruction manual(s) for operating

sampling equipment;

• field data sheets (printed on waterproof

“write in rain” paper, if possible);

• clipboard, preferably with plastic cover;

• several pencils (ink runs when it gets wet;

soft pencils will write on damp surfaces); 

• black indelible ink pens and markers;

• map or photograph of sampling

location(s);

• compass or global positioning system to

help find sampling location(s);

• tide chart;

• cooler and ice (blue ice pack preferably);

• tape measure;

• armored thermometer (non-mercury

preferred);

• wash bottles with distilled or deionized

water for rinsing equipment;

• containers for waste materials (e.g., used

reagents);

• camera and film, to document particular

conditions; 

What to Bring
Once sites are selected, the manager

should mark the sites on a topographic

map or navigational chart. A written

description of the sites should be

developed, using landmarks

or latitude and longitude

coordinates (Stancioff,

1996). Photographs

of the sites can

also be useful to

volunteers.

The manager

may also want to

create a map

showing the

location of

volunteers’ homes

if the program relies on citizens sampling from

their own dock or pier. This map will illustrate

which areas of the estuary still need coverage

and where sites may be too tightly clustered. 

Returning to the Same Monitoring Sites

Once the program manager and volunteers

have chosen monitoring sites, quality control

demands that each volunteer sample from

exactly the same location each time. If the site

is off the end of a dock or pier, returning to

the monitoring site is a simple matter. If,

however, the volunteer reaches the site by

boat, the task becomes more complicated.

Some basic methods to ensure that volunteers

return to the same site are: 

Locating Monitoring Sites, 

or How Do I Get There from Here?

Rocks

Building

Dock

Flag Pole

Figure 7-1. The shoreline landmark method.

7-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

• extra rope/line;

• duct tape, electrical tape, zip ties, sealable

plastic bags, and other items for quick

repair and modification of equipment;

and

• walking stick of known length for

balance, probing, and measuring.

If monitoring from a boat, volunteers should

bring the following additional equipment: 

• one U.S. Coast Guard-approved personal

flotation device for each person aboard (it

is recommended that you wear a life

jacket at all times);

• equipment required by state and local law

(your state boating administration will

have a list, which usually includes such

items as a fire extinguisher and bell);

• anchor;

• weighted line to measure depth; and 

• nautical chart of area.

Helpful Hint

Personal journals kept by volunteers can be

valuable supplements to the information

recorded on data sheets. Volunteer notes on

field observations and sampling activities can

give feedback on sampling methods, aid data

interpretation, and provide a useful historic

record to accompany the data. In addition,

their insights can help future volunteers

understand specific nuances of their

monitoring sites.

The tools, equipment, instruments, and

forms that you take into the field will often

depend on where you are monitoring, your

monitoring techniques, and the parameters

you are measuring. Additional equipment

needed for specific chemical, physical, and

biological monitoring procedures included in

this manual are provided in the relevant

chapters. ■
7-11

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

The Shoreline Landmark Method 

Landmarks—conspicuous natural or

manmade objects—provide a ready means of

identifying a specific monitoring site. Once

the program manager and volunteer have

identified a permanent site, they should

anchor the boat and scan the landscape for

distinctive features. Such features can include

tall or solitary trees, large rocks, water towers,

flag poles, or any other highly visible and

identifiable object. 

Two landmarks, in front-to-back alignment,

should be chosen. The sight line created by

the landmarks will lead directly back to the

site. The volunteer should then pick another

set of aligned landmarks onshore about 90

degrees from the sight line of the first set. The

two sight or bearing lines should intersect at

the boat (Figure 7-1). The volunteer should

practice repositioning the boat at this point. 

In some cases, volunteers must return to

monitoring sites on a coastal pond, sound, or

lagoon located in the middle of a salt marsh or

in some other rather featureless landscape. If

no obvious landmarks are available,

volunteers may want to post two sets of

brightly colored signal flags (Figure 7-2).

They should obtain permission from the

landowner before posting the flags. 

The Marker Buoy Method 

In wind- and wave-protected sections of an

estuary, volunteers may want to set buoys to

mark the monitoring site (Figure 7-3). The

buoy should be brightly colored and easily

distinguishable from fishing buoys floating in

the area. The program manager should check

on local and state regulations regarding buoy

placement before using this method. 

Although a simple means of marking a site,

buoys do not always stay in place; wind,

waves, and passersby may move the buoy or

remove it entirely. Volunteers should use the

shoreline landmark method as a backup to

ensure that the buoy is correctly positioned. 

Global Positioning System (GPS)

In many cases, the lack of a

definitive landmark (e.g., a pier,

outfall pipe, or marker buoy) can

hinder volunteers from reaching

the right sampling location. In

addition, monitoring groups using

certain data management systems

(e.g., Geographic Information

Systems; see Chapter 8) may need

to report specific geographic

locations, often by latitude and

longitude. In such cases, reporting

a location as “across the street

from the firehouse” is

unacceptable. 

While latitude and longitude

can be estimated from a U.S.

Geological Survey topographic

map, volunteers might still be

guessing about their exact

position. The most accurate

method for determining position is using a

Global Positioning System (GPS) receiver.

This tool helps to ensure that the volunteer is

collecting samples at the same location time

after time. As a result,

quality control is

maintained. 

GPS uses a network of

satellites to provide users

with, among other things,

data about their positions

on Earth. With relative

ease, users can locate their

latitude, longitude, and

elevation (although

elevation is usually less

accurate). The volunteer

must be sure to minimize

the blocking of satellite

transmissions by holding

the receiver away from the

body. Buildings or trees

can also cause

interference.

Hole in pole base

Wooden stake

Wire wrapped

around log

Heavy

Stones

Finishing Nail

2”x 2”

pole

Guy Wires

Notches

Tacks

Orange or red

flag with edge

rolled

Figure 7-2. Construction of a landmark

flag (adapted from Compton, 1962).

Figure 7-3. The marker buoy. This instrument

may be used to identify monitoring sites in

sheltered areas of the estuary.
7-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

A variety of GPS receivers exist. Generally,

as a receiver’s accuracy increases, so does its

cost. For example, a GPS unit with a

differential antenna can be very accurate, but

it tends to be more expensive than a unit

without the antenna. ■

Helpful Hint

Accurate GPS receivers can be expensive,

but volunteer groups do not always have to

buy them. Some government agencies loan

them out and some GPS receivers can be

donated. A monitoring group may be able

to borrow a receiver to help pinpoint a

sampling location. Once at the location,

they can place a marker to ensure that they

can easily return to the site.

Usually, taking a water sample to obtain a

water quality variable concentration is not

enough; in fact, it is only part of what is

needed. Once at the monitoring location,

volunteers should take a visual assessment,

which is simply observing and recording the

environmental conditions at the site.

Volunteers should always be on the lookout

for environmental clues that might help

explain the data. A visual assessment of the

monitoring site can provide invaluable

information and make interpretation of other

data easier and more meaningful. For

example, if dead fish are floating at the water

surface, they may signal a sudden drop in

dissolved oxygen (DO) levels, the influx of

some toxic substance, or disease or infestation

of the fish. Unusual visual data are like bait;

they should lure you in for further

investigation. 

The most value is gained when volunteers

assess the same area each time they collect

samples. In this way, the volunteers will

become the local experts—growing familiar

with baseline estuary conditions and land and

water uses, and being better able to identify

changes over time (USEPA, 1997).

When making a visual assessment of the

site, look for and record information about: 

Potential Pollution Sources 

Several programs have started shoreline or

watershed assessment projects to characterize

land uses and land use changes around an

estuary. An assessment can quantify the amount

of—and changes in—residential, industrial,

urban, agricultural, and forested areas within a

watershed. A broader-scope project could

further map the location of construction sites,

marinas, industrial and municipal discharges,

stormwater discharge points, landfills,

agricultural feedlots, and any other potential

pollution sources to the estuary. 

Such an undertaking also provides the

program leaders with information that may

prove useful in selecting additional monitoring

sites. 

Indicators of Pollution 

Water pollution may not be visually apparent,

so other clues can serve as warning of possible

contamination. Lesions on fish, for example,

suggest the possible presence of toxic

contaminants. Surface foam and scum

downstream from a plant’s discharge could be

cause for concern. Although the discharge could

lie within legal limits, a citizen group may want

to investigate the situation further. Other

Making Field Observations: Visual Assessments
7-13

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

pollutant indicators include large numbers of

dead fish or other animals, rust-colored oozes,

large quantities of floatable debris, and highly

turbid water. 

Record all unusual conditions on a data

sheet. Descriptive notes should be as detailed

as possible. Volunteers should bring such

conditions to the attention of the program

leaders so that they can report them to the

appropriate authority, if warranted.

Monitoring groups which function as

watchdogs may want to follow up with an

investigation of their own. 

Living Resources 

A simple assessment of the quantity and

type of living resources can round out the set

of data taken at one site. Numbers of

waterfowl, schools of fish, presence or

absence of submerged aquatic vegetation

beds, change in shoreline vegetation, and

other information relate directly to the area’s

water quality. Fish kills or widespread

shellfish bed die-offs may indicate episodes of

intolerable water quality conditions. The

presence of birds, pets, sea lions, and cattle

may help explain high bacteria

concentrations. 

Remember, however, that the presence or

absence of a living resource does not

definitively speak to the estuary’s water

quality. Many animals are migratory and will

not be seen at certain times of the year. Others

may remain year-round, but become inactive

at times and are difficult to find.

Color 

We tend to think of pure water as blue, yet

few waterbodies north of the sub-tropics fit

this description. Clean water may have a color

depending upon the water source and its

content of dissolved and suspended materials.

Plankton, plant pigments, metallic ions, and

pollutants can all color water (Table 7-1).

Even the color of the substrate can cause the

water to take on an apparent color. To assess

color, use one of the established color scales

such as the Borger Color System or the ForelUle Color Scale from scientific supply

houses. 

Oil Slicks 

Oil slicks are easily recognized by their

iridescent sheen and often noxious odor. Oil

may indicate anything from a worrisome oil

spill to bilge water pumped from a nearby

boat. Estimate the size of the slick, if

possible, and report any spill to local

authorities or the U.S. Coast Guard’s National

Response Center (1-800-424-8802).

Weather Conditions

The weather, recorded at the time of

sampling and for several days beforehand,

helps in the interpretation of other data.

Water Surface Conditions 

Whether calm, rippled, or with waves and

whitecaps, surface water conditions indicate

how much mixing is occurring in the top layer

of the estuary. When the surface is placid,

very little wind-induced mixing occurs.

Waves whipped up by wind, however,

indicate substantial mixing and the

introduction of oxygen to the water. This

information may be especially helpful in

interpreting dissolved oxygen data. 

Table 7-1. Water colors and their possible causes.

Apparent Color Possible Reason

Peacock blue Light-colored 

substrate

Green Phytoplankton

Yellow/Brown Peat, dissolved 

organics

Red/Yellow/Mahogany Algae, 

dinoflagellates

Myriad colors Soil erosion

Rainbow Oil slick
7-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

Ice 

Ice cover can affect dissolved oxygen levels

in the water by limiting the interaction of

water with the atmosphere. In addition, ice in

shallow areas may damage submerged aquatic

plants and temporarily deprive estuarine

animals and waterfowl of their habitat. 

Erosion 

Evidence of recent erosion, such as a

steeply cut bank, may indicate recent storm

activity or substantial wakes from boats. In

either case, highly turbid water may

accompany the erosion. ■

Volunteer monitoring programs should

consider including several other parameters in

their suite of regular measurements. Most are

simple to carry out and provide additional

background information helpful in the final

analysis of an estuary’s status. These

parameters include: 

Air Temperature 

Air temperature can be measured with the

same meter or thermometer used for reading

water temperature. Prior to placing the

instrument in the water sample, allow the

thermometer to equilibrate with the

surrounding air temperature for three to five

minutes; a wet thermometer will give an

erroneous air temperature reading. Make sure

the thermometer is out of direct sunlight to

avoid a false high reading. 

Odor 

Though quite subjective, water odor can

reveal water quality problems that may not be

visually apparent. Industrial and municipal

effluents, rotting organic matter and

phytoplankton blooms, and bacteria can all

produce distinctive odors. Raw sewage, for

example, has an unmistakable aroma. Make

note of the odor in the data record and

describe the smell.

Precipitation 

Precipitation data help the program manager

determine the possible causes of turbidity and

erosion. Turbidity, for instance, generally rises

during and after a rainstorm due to soil runoff.

A wind storm (without precipitation), on the

other hand, might cause turbidity due to

bottom mixing. Precipitation also may help

explain why nutrient concentrations rise (with

rain) or decline (with little rain). 

Be sure to place the rain gauge in an open

area away from interference from overhead

obstructions and post it more than one meter

above the ground (Figure 7-4). Check the

gauge each morning, record the amount of

precipitation and the time of measurement,

then empty the gauge. If the gauge sits after a

rainfall, evaporation can falsify the

measurement. 

Helpful Field Measurements

45 45

1 Meter

Figure 7-4. Rain gauge placement (adapted from Campbell and Wildberger, 1992).
7-15

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

Tides 

Programs studying highly stratified

estuaries or estuaries with tidal ranges over a

few feet may want to measure tidal stage.

Tides of sufficient magnitude are effective

mixers of estuarine waters and may break

down stratification. Even if tidal stage data

are not included at the beginning of the

sampling effort, the National Oceanic and

Atmospheric Administration (NOAA)

publishes tide tables for most of the U.S., and

this information can be obtained and applied

after the fact if the monitoring station is

reasonably close to one of the published tide

table sites. ■

Units 1-3 in this manual specify sampling

and equipment procedures for different

chemical, physical, and biological water

quality parameters. There are, however,

several general tasks that apply whenever

water samples are collected. As always,

program managers should consult with their

laboratory or their sampling equipment

instructions for exact requirements.

Before Leaving Home: Preparation of

Sampling Containers

Reused sample containers and glassware

must be cleaned and rinsed before and after

samples are taken. When preparing sampling

containers for most chemical and physical

water quality parameters, follow these steps:

1. Wear latex or rubber gloves.

2. Wash each sample bottle or piece of

glassware with a brush and phosphatefree detergent.

3. Rinse three times with cold tap water.

4. (This step is only for sample containers

and glassware used to monitor nitrogen

and phosphorus.) Rinse with 10 percent

hydrochloric acid.

5. Rinse three times with deionized water.

Equipment used for bacteria sampling must

be sterilized in an autoclave, which may

require the assistance of a certified lab. 

In the Field: Sample Collection

There are several different water collection

devices available today. They can be used for

most water quality analyses in the field or

laboratory. 

Surface Samples

Screw-cap bottles and Whirl-pak bags

(Figure 7-5) are among the most popular tools

for collecting water samples near the surface.

The following steps should generally be taken

(USEPA, 1997):

• Screw-Cap Bottle

1. Using a waterproof pen, label the bottle

with the site number, date, and time.

2. Unscrew the bottle cap immediately

prior to sampling. Avoid touching the

inside of the bottle, its lip, or the cap. If

you accidentally touch either, use

another one.

3. Wading: 

Try to disturb as little bottom sediment

as possible and take care not to collect

water that has sediment from bottom

disturbance. Stand facing against the

current or tide (if it can be detected).

Collect the sample against the current,

in front of you (Figure 7-6). You may

also tape your bottle to an extension

pole to sample from deeper water.

How to Collect Samples
7-16

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

Boat: 

Carefully reach over the side;

collect the water sample on

the upcurrent side of the boat.

4. Hold the bottle near its base

and plunge it (opening

downward) below the water

surface (Figure 7-6). If you

are using an extension pole,

remove the cap, turn the

bottle upside down, and

plunge it into the water,

against the current or tide.

Collect the water sample 8-12

inches below the water

surface whenever possible.

5. Turn the bottle into the current and

away from you. In slow-moving waters,

push the bottle underneath the surface

and away from you against the current

or tide.

6. Leave a 1-inch air space (except for

dissolved oxygen and biochemical

oxygen demand samples), so that the

bottle can be shaken just before

analysis. Recap the bottle carefully,

remembering not to touch the inside of

the bottle or its lip.

7. Fill in the bottle number and/or site number on the appropriate field data sheet.

8. If the samples are to be analyzed in the

lab, place them in the cooler for transport

to the lab.

• Whirl-pak Bag

1. Using a waterproof pen, label the bag with

the site number, date, and time.

2. Tear off the top of the bag along the perforation above the wire tab just prior to sampling (Figure 7-5). Avoid touching the

inside of the bag. If you accidentally touch

the inside of the bag, use another one.

3. Wading:

Try to disturb as little bottom sediment as

possible. In any case, be careful not to collect water that contains sediment. Stand

facing against the current or tide. Collect

the water sample in front of you.

Boat:

Carefully reach over the side; collect the

water sample on the upcurrent side of the

boat.

4. Hold the two white pull tabs in each hand

and lower the bag into the water with the

opening facing against the current. Open

the bag midway between the surface and

the bottom by pulling the white pull tabs.

The bag should begin to fill with water.

You may need to “scoop” water into the

bag by drawing it through the water

against the current and away from you.

Fill the bag no more than 3/4 full.

5. Lift the bag out of the water, pouring out

excess sample. Pull on the wire tabs to

close the bag. Continue holding the wire

tabs and flip the bag over several times

away from you to quickly seal the bag.

Fold the ends of the wire tabs together at

the top of the bag, being careful not to

puncture the bag. Twist them together,

forming a loop.

Perforation

Wire Tab

Pull Tab

water flow

water flow

water flow

water flow

Figure 7-5. Whirl-pak bag. Volunteers can

be easily trained to collect water samples

with these factory-sealed, disposable bags.

Figure 7-6. Taking a water sample. Turn the container into the current or tide and

scoop in an upcurrent direction (redrawn from USEPA, 1997).

1

2

3

4
7-17

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

6. Fill in the bag number and/or site number

on the appropriate field data sheet. 

7. If the samples are to be analyzed in the

lab, place them in the cooler for transport

to the lab.

Samples at Depth

To accommodate at-depth measurements,

equipment supply companies produce several

types of water samplers designed to collect

water at specific depths through the water

column. 

Two of the most commonly used samplers in

citizen monitoring programs are the Van Dorn

and Kemmerer samplers (Figure 7-7). Both

samplers have an open cylinder with stoppers at

both ends. A calibrated line attaches to the

device and allows the volunteer to lower the

unit into the water to a precise depth. 

After lowering the unit into the water to the

proper depth, the volunteer then releases a

“messenger”—or weight—down the line. When

the messenger hits the sampler, it trips a releasing mechanism and two stoppers seal off the

ends of the tube. 

If sampling routinely takes place from a

bridge, the manager should install a lighter

weight messenger on the sampler. Be

warned, however, that repeated use of the

standard messenger from such heights will

eventually damage the unit. 

The volunteer should pull the sampler to

the surface and transfer the collected water

into a sample bottle or—depending on the

parameter to be measured—a Whirl-pak

bag. Pouring the water from one container

to another can aerate the sample, thereby

biasing some results (e.g., for dissolved

oxygen). To avoid aeration, the volunteer

should transfer the water using a rubber

hose with an attached push valve. With the

end of the hose at the bottom of the empty

sample container, the volunteer should fill

the bottle to overflowing. 

Van Dorn and Kemmerer samplers, their

derivations, and samplers designed for

particular water quality parameters (e.g.,

dissolved oxygen) are available from

equipment suppliers (Appendix C). Several

volunteer groups have also constructed

their own samplers. ■

Kemmerer

Water Sampler

Van Dorn

Water Sampler

Figure 7-7. Two common

water samplers: Kemmerer

and Van Dorn (from APHA

et al., 1998).

In several places in this chapter and

throughout the manual, the importance of

volunteers completing the data form or data

sheet is expressed. The forms, when properly

filled out, provide a set of standardized data

useful to both managers and scientists.

Volunteer program leaders are responsible for

continuously emphasizing that properly

completed data forms are essential to data

quality. Rarely can a data manager feel

comfortable asking a volunteer about details

from the previous week’s sampling exercise;

relying on memory is risky.

Data forms should be easy to

use and have space for water

quality data and all information

necessary to analyze, present,

and manage the data. Sample

data forms are provided in

Appendix A. As a backup to the

data form, some volunteers may

wish to bring a tape recorder

into the field to record

observations.

While data users and the

database manager should be

The Data Form

Volunteers collecting bacteria samples

using an extension pole (photo by Weeks

Bay Watershed Project).
7-18

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

involved in the development of the

data collection form, consideration

should also be given to the ease with

which volunteers can fill out and

understand the form (USEPA, 1990). If

the information is not important to the

project, it should not be asked for on

the data form. 

One way to better ensure that volunteers

complete the data forms correctly and

completely is to involve them in the forms’

development. Periodic reviews of the forms

should also be conducted. As volunteers gain

experience with the forms and monitoring

sites, they can provide excellent suggestions

for improving the data forms. ■

References and Further Reading

Volunteers collecting a water

sample from a dock using a

dissolved oxygen sampler 

(photo by K. Register).

Portions of this chapter were excerpted and adapted from:

Maine Department of Environmental Protection (DEP). 1996. A Citizen’s Guide to Coastal

Watershed Surveys. 78 pp.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A

Methods Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

Other references:

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L.S. Clesceri, A.E. Greenberg, A.D. Eaton (eds). Washington, DC.

Campbell, G., and S. Wildberger. 1992. The Monitor’s Handbook. LaMotte Company,

Chestertown, MD. 71 pp.

Compton, R. 1962. Manual of Field Geology. John Wiley and Sons. New York. 

Ellett, K. 1993. Chesapeake Bay Citizen Monitoring Program Manual. Alliance for the

Chesapeake Bay. Richmond, VA. 57 pp.

Ely, E. 1995. “Determining Site Locations.” The Volunteer Monitor 7(1).

Lee, V., D. Avery, E. Martin, and N. Wetherill. 1992. Salt Pond Watchers Protocol #1: Field

Sampling Manual. Coastal Resources Center, University of Rhode Island. Tech. Rpt. No. 14.

27 pp.
7-19

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field

McAninch, T. 1997. “Guarding Against Reagent Degradation.” The Volunteer Monitor 9(1).

Stancioff, E. 1996. Clean Water: A Guide to Water Quality Monitoring for Volunteer Monitors of

Coastal Waters. Maine/New Hampshire Sea Grant Marine Advisory Program and University

of Maine Cooperative Extension. Orono, ME. 73 pp.

U.S. Environmental Protection Agency (USEPA). 1990. Volunteer Water Monitoring: A Guide

for State Managers. EPA 440/4-90-010. August. Office of Water, Washington, DC. 78 pp.

U.S. Fish and Wildlife Service. 1997. Introduction to GPS for Field Biologists (TEC7132). Sept.

25-26, 1997. Shepherdstown, WV. National Conservation Training Center.
7-20

Volunteer Estuary Monitoring: A Methods Manual

Chapter 7: In the Field
Chapter 8 Data Management, Interpretation, and Presentation

Data are like letters of the alphabet: taken individually, they reveal very little. Put

together with a little thought and organization, however, those same letters can tell a

complete story. By highlighting data management, interpretation, and presentation,

this chapter shows how data can be used to tell a story about your estuary. 
Photos (l to r): The Ocean Conservancy, L. Monk, The Ocean Conservancy, K. Register
8-1

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

Volunteer estuary monitoring objectives differ from one program to the next.

Meeting those objectives, however, usually requires similar steps. Regardless of

whether a volunteer program wants to use its data for citizen education or resource

management, the program must make its data understandable to its audience.

Many goals will be unmet if the volunteer program cannot clearly convey what its

data say about the estuary.

Data are like letters of the alphabet: taken individually, they reveal very little. Put

together with a little thought and organization, however, those same letters can tell a

complete story. By highlighting data management, interpretation, and presentation,

this chapter shows how data can be used to tell a story about your estuary. 

Overview
8-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

Consider this situation: You have the

monitoring equipment. Volunteers are in the

field collecting data. Enthusiasm is high.

Everything is going smoothly and it’s time to

relax.

But is it really? 

As difficult as it may be to accept, the

aforementioned situation means one thing:

there is much more work to be done. What

will you do with the incoming data? As

discussed in previous chapters, monitoring

organizations should know the answer to this

question before they collect their first sample.

These decisions are made, in part, based on

the needs of potential data users, who are

particularly concerned about:

• databases and software used to manage

the data;

• procedures followed in order to verify

and check the raw volunteer data;

• analytical procedures employed to

convert the raw data into findings and

conclusions; and

• reporting formats.

Knowing how the data will be used should

drive the development and everyday

management of a volunteer monitoring

program. 

Most programs intend to use their data to

tell a story about the estuary’s health.

Similarly, most volunteers who collect the data

want to know what their information reveals

about the estuary. Without communicating that

data in a meaningful way to your intended

audience, the hard work of many volunteers

and volunteer leaders could be wasted. To take

information from data sheets and convert it to

something that makes sense to your audience

requires several elements, which are

summarized in Figure 8-1 and described in the

remainder of this chapter. ■

After Data Collection: What Does It Mean?

Data Management

As discussed in previous chapters, data

sheets should not only be easy for volunteers

to complete, but should also record all desired

information about the estuary and the

sampling sessions. The volunteer leader

cannot overemphasize to volunteers the

importance of careful and accurate data

recording. Incomplete or inaccurate data

sheets can cause serious problems when it

comes time to interpret the data. Such problems can damage your program’s credibility

and/or render the data useless, making all

worthwhile efforts futile.

Data management is everyone’s responsibility. The commitment by volunteers to

collect high quality data must be matched by

the program’s commitment to make the

information understandable to its volunteers

and other data users. From the very early

stages of planning a volunteer monitoring

program, a sound data management plan must

be a priority. It should be clear how the data

will be processed, when it will be processed

and reported, and who will be responsible for

each task. An attitude of “Let’s just get the

Data data now and figure out what to do with it

Management

Data Analysis/

Interpretation

Data

Presentation

Data

Collection

Data Sheet

INTRODUCTION

Figure 8-1. Steps

necessary to prepare

data for presentation.

Data tell a story about

the estuary.
8-3

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

later” can lead to wasted time and effort and a

huge data backlog.

Where Does the Data Go?

It is difficult to get any meaning from boxes

full of data sheets. The information collected

by volunteers needs to be organized and

readily accessible. Years ago, this may have

meant that the data might be organized in

handwritten tables. This method is still an

option, but a computerized data management

system provides a great deal of advantages,

especially if the data collection effort is

conducted at many sites and/or over a long

time period (Lease, 1995). 

Database or Spreadsheet?

Today’s computer software includes a

variety of spreadsheet and database packages

that allow you to organize the data and

perform statistical analyses. These options

make it easier to detect relationships between

data points. Spreadsheets are adequate for

most data management needs and have the

advantage of being relatively simple to use.

Most spreadsheet packages have graphics

capabilities that will allow you to plot your

data onto a graph of your choice (i.e., bar,

line, or pie chart). Examples of common

spreadsheet software packages are Lotus 

1-2-3, Excel, and Quattro Pro.

Database software may be more difficult to

master and usually lack the graphics

capabilities of spreadsheet software. If you

manage large amounts of data, however,

having a database is almost a necessity. It can

store and manipulate very large data sets

without sacrificing speed. The database can

also relate records in one file to records in

another. This feature allows you to break your

data up into smaller, more easily managed

files that can work together as though they

were one. 

The ability to query data is one of the most

significant advantages of using a database.

For example, the user can search for records

that show water temperature exceeding X

degrees over a specified time period, or

identify monitoring sites that have dissolved

oxygen levels between X and Y and the dates

of those observations. The questions can be

simple or quite complex and the answers or

output can be organized in a variety of ways. 

If you use a database for data storage and

retrieval, you may still want to use a

spreadsheet or other program with graphics

capabilities. Many spreadsheet and database

software packages are compatible and will

allow you to transport data sets back and forth

with relative ease. Specific parts of the

database (such as results for a particular water

quality variable from all stations and all

sampling events) can then be transported into

the spreadsheet, statistically analyzed, and

graphically displayed. Examples of popular

database software packages are dBase,

Access, FileMaker Pro, and FoxPro. 

Designing a Data Management System

Many people are capable of writing their

own programs to manipulate and display data.

The disadvantage of using a “homegrown”

software program, however, is that if its

author leaves the monitoring program, so too

does all knowledge about how the program

works. Commercial software, on the other

hand, comes with consumer services that

provide over-the-phone help and instructions,

users’ guides, replacement guarantees, and

updates as the company improves its product.

Most commercial programs are developed to

import and export data in standard formats.

This feature is important because if you want

to share data with other programs or

organizations, all you need are compatible

software programs. However, some file

conversions may be more difficult than

advertised by the software manufacturer. To

avoid potential problems, consult with any

groups, government agencies, or laboratories

with whom you plan to share data and ensure

that your software packages are compatible

(Lease, 1995).
8-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

When designing databases or spreadsheets,

always keep in mind what you will ultimately

do with the data. Will you produce graphs or

reports? Will you need to show a map with

key data collection sites? Try to design your

data management system in a manner that will

make it easy to generate your final product.

Another consideration is who will input the

data and create the final products. As more

people, and especially volunteers, are

involved in data entry and management, more

emphasis should be placed on making the

system easy to use. 

Helpful Hint

Ease of data entry is always an important

element to consider. Here are some

suggestions:

• Design the database or spreadsheet

before you collect any data—this will

help in the creation of your data sheets. 

• Ideally, the database or spreadsheet

input screen and the field data sheets

used by volunteer monitors should look

alike. 

• Design the database or spreadsheet in

such a way that it is readily apparent

where data should be entered. Data cells

can be highlighted with a special color,

for example.

Shared Databases

Greater efforts are being made to develop data storage systems that facilitate data exchange

among different monitoring groups. A shared database serves to assimilate all the data being

collected in a particular region and therefore helps to increase understanding of environmental

conditions. Volunteer organizations are increasingly being encouraged to submit their data to

these shared databases. 

To participate in a shared database, the volunteer organization usually must have a quality

assurance project plan (see Chapter 5) that meets the requirements of the group maintaining

the shared database. Using software programs that are compatible with the shared database

may also be necessary.

Shared databases may be developed for a specific resource (e.g., a river) or as a general

clearinghouse of information. One example of a broad database is the U.S. Environmental

Protection Agency’s (EPA’s) national water and biological data storage and retrieval system,

called STORET. With STORET, volunteer programs can submit data to a centralized file

server which permits national data analyses and through which data can be shared among

organizations. A specific set of quality control measures is required for any data entered into

the system. For more information, see the EPA Web page at www.epa.gov/owow/STORET/.

Data sharing also occurs at the state level. For example, the Oregon Department of

Environmental Quality (DEQ) will accept data from volunteers and load it into an in-house

monitoring database, the Laboratory Analytical Storage and Retrieval (LASAR). These data

are then periodically uploaded to the STORET system. The Department has established a

Required Data Elements Policy to enhance the widest use of data collected in Oregon. Visit

the DEQ Web site for contact information and a copy of the policy:

http://www.deq.state.or.us/wq/.
8-5

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

Coding Systems

Any data management system should be

flexible enough to meet future needs,

especially as data start to accumulate. An

easily understood coding system will help

simplify the tracking and recording of data.

Codes developed for sample sites, parameters,

and other information on field and lab sheets

should parallel the codes you use in your

database. If you will be sharing your

information with a state or local natural

resource agency, you may want your coding

system to match or complement the agency’s

system. 

Sample Sites

Because sample sites tend to change or grow

in number over time, it is important to have an

accommodating site numbering system. A good

convention to follow is to use a site coding

system that includes an abbreviation of the

waterbody or project plus a site number (e.g.,

GOR021 for a site on the Gooms River). By

using a site abbreviation and three-digit code,

999 sites can be created for each project, which

is plenty for most volunteer programs.

Water Quality Parameters

It is also important to develop a coding

system for each of the water quality parameters

you are testing. These are the codes you will

use in the database or spreadsheet to identify

and extract results. To keep the amount of

clerical work to a minimum, abbreviate without

losing the ability to distinguish parameters from

one another. For example, EC could represent

E. coli bacteria and FC could be the code for

fecal coliform bacteria.

Reviewing Data Sheets

Writers have editors to look for mistakes in

grammar, punctuation, etc. Similarly,

someone should be available to review

volunteers’ data sheets. Even the best

professionals and volunteers can make data

recording mistakes; misplaced decimal points,

forgotten calculations, or data values

accidentally left blank are entirely possible.

The program coordinator or designated data

analyst should screen and review the field

data sheets immediately as they are received

and before the data are entered into the

database or spreadsheet. Waiting to review the

data sheets for discrepancies is not advised;

the longer you wait, the more likely it is that

the person who collected the data will forget

important details about the sampling effort

that could clarify any inconsistencies.

When reviewing the data sheets, the

program coordinator or other designated

person should ask the following:

• Are the field data sheets complete?

If a person is consistently leaving a section

of the sheet incomplete, ask why. You may

learn that he or she is unclear about a

monitoring procedure or has misunderstood

some instructions. 

• Are the monitoring results very different

from what might usually be expected for the

site? If unexpected, are they still within the

realm of possibility? 

For example, can the kit or technique used

actually produce the reported results? Does

the monitor offer any possible explanations

for the results (e.g., a sewage treatment plant

malfunction had been recently reported)? Is

there additional corollary information that

supports the data (e.g., a fish kill has been

observed along with the extremely low

dissolved oxygen readings)? 

Also check for consistency between similar

parameters. For example, total solids and

turbidity should track together—if one goes

up, so should the other. 

• Are there outliers—findings that differ radically

from past data or other data from similar sites?

Values that are off by a factor of 10 or 100

should be questioned. Follow up on any data

that seem suspect. If you cannot explain why

the results are so unusual, but they are still

within the realm of possibility, you may want to
8-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

flag the data as questionable. Ask an

experienced volunteer or program staff member

to sample at that site as a backup until

uncertainties are resolved, or work to verify that

proper sampling and analytical protocols are

being followed. Besides suggesting human

error, monitoring results that are radically

different than usual can indicate a problem with

the monitoring technique or a new and serious

problem at the monitoring site.

• Are all measurements reported in the

correct units?

Minimize the chance for error by including

on the data form itself any equations needed to

convert measurements and specify on the form

what units should be used. Check the math,

making sure that the monitor has followed the

program’s rules for rounding numbers and

reporting the appropriate number of decimal

places. A value of zero should not be reported;

instead, report the value as less than the lowest

value that can be read with the equipment

(Miller, 1995). For example, if the range of a

test is 0-1 mg/l, the smallest increment is 0.01

mg/l, and the test result is zero, report the value

as “less than 0.01 mg/l” or “<0.01 mg/l.” 

All field data sheets should be kept on file

in the event that findings are brought into

question at a later date and to serve as backup

in case the computer-entered data are lost.

Helpful Hint

Reviewing data sheets doesn’t only make

you aware of recording mistakes, but it can

also alert you to problems with your test

procedures. Ideally, results for a particular

test procedure should fall within the middle

range of the test. For example, if a test

range is 0-100 mg/l, most values should fall

somewhere in the middle. If your volunteers

are reporting many values of less than 10

mg/l, the precision for that test will not be

very good. You may need to switch to a

method having a range of 0-10 mg/l.

(Excerpted and adapted from Miller, 1995.)

Double-Checking Data Entry

Just as mistakes can be made recording data

on paper, errors can also be made entering

data into a computerized database or

spreadsheet. This possibility requires that the

data be printed and proofread against the

original field data sheets. Preferably, someone

other than the person who entered the data

should serve as proofreader. 

As a further check, you can make some

simple calculations to ensure that no errors

have slipped through. For example, if the

median and the mean are very different, an

outlier may be skewing the results. If you find

an outlier, check for calculation or data entry

errors. If the unusual data points cannot be

explained by backup information on the field

data sheets or the comment field in the

database, flag the data as questionable until

they can be verified.

Your database or spreadsheet can also be

designed to minimize common data entry

errors. One way to reduce error is to restrict

acceptable input possibilities to those that are

within the realistic range of values for a

particular water quality variable. For example,

the data program can be made to reject pH

data values greater than 14, since such values

are not possible. ■

Helpful Hint

It is always a good idea to make backups of

any electronic database or spreadsheet.

Duplicate files should be made on disk or

tape and stored at another site, if possible.

To further protect your data from some

unfortunate disaster, print and store

hardcopies of all data sets and keep the

original data sheets.

(Excerpted and adapted from Sayce, 1999.)
8-7

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

Data Interpretation

While computers are quite helpful in

organizing data, deciphering the story behind

these facts remains a human job. The overall

purpose of data interpretation is to get

answers to your study design questions—the

same questions that originally provoked you

to start your monitoring program. 

As an example, imagine that you want to

determine where water quality criteria are not

being met in the estuary. To do this, you must

first develop preliminary findings, or objective observations about your data (Dates,

1995). By looking at the data, for example,

you might be able to identify:

• variables that failed to meet water

quality criteria;

• monitoring sites that regularly failed to

meet the criteria;

• dates on which most or all of the sites

did not meet the criteria, and the

environmental conditions (e.g., weather,

flow) on those dates;

• sites upstream and downstream of a

suspected pollution source that show

different monitoring results; and

• changes in one water quality variable

that coincide with changes in another.

Your findings will help you look more

critically at the data. With the facts in hand,

you might naturally want to figure out why

the data are what they are, especially if your

findings reveal that water quality criteria are

not met in certain areas. This will require

more effort, but is certainly worthwhile: once

reasons for poor water quality are found,

solutions can be developed.

Ask yourself questions to help you decide

whether human alterations, natural conditions,

and/or data collection processing mistakes

might explain your results. 

• Could weather influence your results

(e.g., do problem levels coincide with

intense rainstorms)?

• Do specific sources explain your results

(e.g., can increased bacteria levels be

attributed to a wastewater treatment

plant, failing septic system, or a large

population of waterfowl or domesticated

animals)? 

• Do changes in one of your indicators

appear to explain changes in another?

For example, high temperatures (caused

by a thermal discharge or a heat wave)

might explain low oxygen levels.

• Do your visual observations explain any

of your results? Did your samplers

report any strange pipes, construction

activity, flocks of birds, or dry weather

discharges from storm drain pipes? 

• For multiple years of data, are there

overall trends? For example, did the

submerged aquatic vegetation (SAV)

community improve or deteriorate over

time? The former could be explained by

improved pollution control; the latter, by

new pollution sources. 

• If you are monitoring the impact of a

pollution source (e.g., a wastewater

treatment plant), are there other

upstream impacts that might be

influencing and confusing your results?

For example, if a dairy farm is located

immediately upstream from the

wastewater treatment plant that you are

monitoring, it might be difficult to

figure out which source is causing the

water quality problems revealed by your

data. Alternatively, it could be difficult

to determine how the two sources

combine to cause the problems.

• Could unusual or unexpected data be

attributed to contaminated samples or

human sampling error?

• Did the time of sampling affect your

results? For example, dissolved oxygen

levels are generally lowest in the early

morning hours. Sampling for dissolved
8-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

oxygen in the afternoon could overlook

the estuary’s worst-case conditions.

• Could the water quality variable occur

in several places throughout the

ecosystem? For example, if you found

low levels of phosphorus in the water

column, there might be high levels in

bottom sediments or plants. Algae

blooms are evidence of nutrient

enrichment that may not be apparent in

water samples.

Helpful Hint

Comparing older photos with more recent

ones from the same location can help

volunteers understand changing land uses

and perhaps help you interpret water quality

changes.

Summary Statistics 

Summary statistics describe the basic

attributes of a set of data for a given

parameter. There are many different types of

statistics that can be used. Program leaders

should consult a standard statistics manual,

their data users, and their quality

assurance project plan to

determine which statistical

methods are most appropriate

for their data. Two of the most

frequently used descriptors of

environmental data are the

mean and standard deviation.

They are briefly described here.

Textbook statistics commonly

assume that if a parameter is

measured many times under the

same conditions, then the

measurement values will be

randomly distributed around the

average with more values

clustering near the average than

further away. In this ideal

situation, a graph of the

frequency of each measure

plotted against its magnitude

should yield a bell-shaped or normal curve.

The mean and the standard deviation

determine the height and breadth of this

curve, respectively (Figures 8-2 and 8-3). 

The mean is simply the sum of all the

measurement values divided by the number of

measurements. Commonly referred to as the

“average,” this statistic marks the highest point

at the center of a normal curve (Figure 8-2). 

The standard deviation, on the other hand,

describes the variability of the data points

around the mean. Very similar measurement

values will have a small standard deviation,

while widely scattered data will have a much

larger standard deviation (Figure 8-3). A high

standard deviation indicates imprecise data

(see Chapter 5 for a discussion of precision

and an equation for calculating standard

deviation).

While both the mean and the standard

deviation are quite useful in describing

estuarine data, often the actual measures do

not fit a normal distribution. Other statistics

sometimes come into play to describe the

data. Some data are skewed in one direction

or the other, while others might produce a

flattened bell shape (Figure 8-4). 

Deviation from the normal distribution

often occurs in estuary sampling because the

estuary is dynamic, with many factors

influencing the condition of its waters. The

various methods used to collect data can also

cause non-normal distributions. For example,

if volunteers are collecting water quality data

in SAV beds (see Chapter 18), the distribution

of water quality variables will tend to be

skewed toward good water quality because

water quality has to be of a certain minimum

standard to support the growth of these

underwater plants. 

Another common cause of non-normal

distribution occurs because of detection

limits. A detection limit marks the boundary

above or below the concentrations or values

measured by a particular method. Secchi

depth measurements, for example, have an

upper detection limit determined by water

depth (i.e., the Secchi depth cannot exceed the

water depth) and a lower limit determined by

Value

Mean

Frequency

Value

Mean

Frequency

Figure 8-2. Graphic

representation of the

mean. The mean is

located at the peak of a

normal or bell-shaped

distribution curve.
8-9

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

the smallest increment of measure on the

rope. Figure 8-5 shows how both low and

high values may be truncated by these

detection limits. 

Mystery Solved?

We might like to think our data will tell us

everything about what is happening in the

estuary. In reality, the data may not tell the

whole story—or even part of it. As with any

scientific study, your data may be inconclusive, especially if your program has been

monitoring for only a short time (Dates,

1995). Indeed, since the workings of an

estuary are complex, it is often difficult to

determine trends for many water quality

variables (e.g., nutrients) unless the

monitoring has occurred over several seasons.

In fact, several years’ worth of unusual data

may be quite misleading and tell a story very

different than the long-term situation.

Concluding that you need additional

information to better understand the estuary is

completely acceptable.

On the other hand, anomalous data can

indicate problems requiring immediate action.

For example, data showing high

turbidity and accompanied by

visual observations of

abnormally cloudy water could

indicate a significant sediment

or nutrient runoff problem from

many possible sources (e.g.,

construction sites, farmland,

forestry operations, golf courses,

etc.). Such information should

be brought to the immediate

attention of proper authorities for

further investigation.

Keep in mind that your data

should support your interpretations.

Still, your interpretations are

simply your best judgments about

the data. Even if you include your

volunteers, data users, and others

who are knowledgeable about the estuary in

reviewing the data, others may disagree with

your interpretation. That is not atypical.

However, as long as your data support your

interpretation and you have followed a

reasonable data interpretation process, you

should be able to defend your position. ■

Value

Mean

Frequency

S=1

S=2

S=3

Normal (Bell-shaped)

Right Skewed

Left Skewed

Flattened

Frequency

Value

0

0.5

1

1.5

2

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Minimum

measure on

Secchi rope

Depth of

water at site

Secchi Depth (meters)

Month

Figure 8-3. Graphic representation of

the standard deviation. A small standard

deviation corresponds to a “peaked” frequency distribution, while a larger standard deviation corresponds to a more

“flattened” distribution. 

Figure 8-4. Examples of frequency distributions.

Because of the complexity of estuarine systems,

deviations to the normal bell-shaped distribution

curve are common.

Figure 8-5. Example of limitations on Secchi depth

measurements in an hypothetical monitoring program.
8-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

When you feel

fully confident that

you have assembled

the best possible

picture of

environmental

conditions in your

study areas, it is

your job to make

others—your

volunteers, data

users, local fishing

clubs, or any other

audience—aware of

what you found.

Know Your Audience

Whether citizen programs convey

monitoring results in a periodic newsletter,

annual report, or by verbal presentation, the

key to rousing and sustaining the interest of

the audience remains the same. The speaker

or writer must determine the interests,

background, and level of technical

understanding of the target audience and

prepare the presentation accordingly.

Remember: The burden of communication is

on the presenter to convey the information,

not on the audience to understand (Sayce,

1999).

In presenting data results to volunteers or

other interested parties, several points merit

consideration: 

• Highly technical or extremely simplistic

presentations bore the audience. An

informative and lively approach, molded

to the expectations of the audience, will

be far more effective. Simple graphics

often help make complicated issues

much more understandable. 

• A presentation should focus on a clear

message related to your audience’s

interests. Your audience will likely be

more interested in specifics such as

trends in water quality, seasonal

variation, quality assurance issues, or

the identification of trouble spots in the

estuary rather than an across-the-board

synopsis of all the monitoring results. 

• Data presentations, whether written or

verbal, should be both timely and

relevant. Volunteers will maintain a

higher level of interest if they see a

quick turnaround of their data into

usable and informative graphics and

summaries. Moreover, your nutrient

data won’t have much influence on

community decision-makers if you miss

the public hearing on a sewer upgrade

project. As mentioned earlier, trends

may be difficult to determine with

limited data, so one should exercise

caution when implying that data show

long term trends.

• Better understanding on the part of your

audience may lead to more community

support, more funding, better

management policies, and greater

citizen involvement.

When presenting data, one of your chief

goals should be to maintain the attention and

interest of your audience. This is very difficult

using tables filled with numbers. Most people

will not be interested in the absolute values of

each parameter at each sampling site; rather,

they will want to know the bottom line for

each site (e.g., is it good or bad) and seasonal

and year-to-year trends. 

Data Presentation 

A project coordinator in Puerto Rico reviews 

the significance of marine debris data with her

young volunteers. Presentations should be 

designed according to the type of audience

(photo by L. Monk).
8-11

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

Graphics

Graphics, when used properly, are excellent

tools to present a great deal of information in

a condensed yet understandable format. They

enliven the presentation, highlight trends, and

illustrate comparative relationships. Graphics

include flowcharts, maps, and graphs or charts

of the data. Such graphics, along with

narrative interpretation, summary statistics,

tables, overheads, and slides, help construct a

well-rounded and interesting presentation. 

Graphs and Charts

Results summarized from the volunteercollected data can be displayed in any of

several styles of graphs. Choosing the style

that best conveys the information is critical

and requires careful thought. Although more

sophisticated graphic styles may be required

to present some data, three basic types are

often used for volunteer monitoring data: the

bar graph, pie chart, and line graph. 

Bar Graph

The bar graph uses

simple columns (Figure

8-6). The height of

each column represents

the value of a data

point, making

comparisons of the data

relatively easy. 

Modifications can be

made to the standard

bar graph for visual

appeal. For example,

Figure 8-7 shows

Technical vs. Non-Technical Audiences

When addressing water quality or planning professionals, you should provide information about: 

• the purpose of the study;

• who conducted it; 

• how it was funded; 

• the methods used; 

• the quality control measures taken; 

• your interpretation of the results; 

• your conclusions and recommendations; and 

• further questions that have arisen as a result of the study. 

Graphics, tables, and maps may be fairly sophisticated. Be sure to include the raw data in a

written report’s appendix and note any problems encountered. 

A report for the general public should be short and direct. It is very important to convey

information in a non-technical style and to include definitions for terms and concepts that may be

unfamiliar to the layperson. Simple charts, summary tables, and maps with accompanying

explanations can be especially useful. Include a brief description of the program, the purpose of

the monitoring, an explanation of the parameters that were monitored, the location of sample

sites, a summary of the results, and any recommendations that may have been made.

In any written report or presentation, you should acknowledge the volunteers and the sources of

funding and other support.

(Excerpted and adapted from USEPA, 1997.)

50

40

30

20

10

0

#1 #2 #3 #4

Category

Units

Figure 8-6. Bar graph.
8-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

turbidity data, as measured by a Secchi disk.

In this graphic, depth increases in a

downward direction along the vertical axis to

simulate actual water depth. This minor

change from the norm, along with the use of

Secchi disk icons extending down from the

“surface,” makes the data easy to understand.

In bar graphs of pH, dissolved oxygen,

bacteria, or other water quality variables for

which a standard value exists, consider

inserting a line across the graphic showing the

standard (Figure 8-8). This helps in

understanding when your results indicate

problems.

Pie Chart

The pie chart (Figure 8-9) is a simple yet

effective means of comparing each category

within the data set to the whole. It is best used

to present relational data, such as percentages.

The chart’s pie shape, with the pie

representing the total and the individual

wedges representing distinct categories,

makes this graphic style popular due to its

simplicity and clarity. 

Certain data may be better described by a

pie chart than others. For example, it can be

very useful for summarizing the composition

percentages of marine debris found at a

particular site (e.g., the percent of plastic,

paper, glass, etc., debris), but not for

presenting dissolved oxygen trends. 

Helpful Hint

If there are many small percentages in your

pie chart, consider reducing the clutter by

grouping the values together as an “other”

category. Identify the items in the “other”

slice of the pie elsewhere, especially if you

are presenting the information to a

technical audience.

0

0.5

1

1.5

2

2.5

1-May15-May1-Jun16-Jun1-Jul16-Jul1-Aug16-Aug1-Sep16-Sep1-Oct16-Oct31-Oct

Secchi Depth (meters)

Not permissible for swimming

Permissible for swimming

Desirable for

swimming

Permissible for boating and fishing (under 5,000)

1200

1000

800

600

400

200

0

1-May

15-May

1-Jun

16-Jun

1-Jul

16-Jul

1-Aug

16-Aug

1-Sep

16-Sep

1-Oct

16-Oct31-Oct

No. of Fecal Coliform Bacteria

in 100 ml water

Category 1 Category 4

Category 3 Category 2

Figure 8-7. Modification of typical bar graph to illustrate Secchi depth data.

Figure 8-8. Bar graph showing fecal coliform data values and comparing them

with water quality standards.

Figure 8-9. Pie chart.
8-13

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

Line Graph

A line graph (Figure 8-10) is constructed by

connecting the data points with a line. It can

be effectively used for depicting changes over

time or space. This type of graph places more

emphasis on trends and the relationship

among data points and less emphasis on any

particular data point. 

Line graphs can also be used to compare

two water quality variables that may be

related. Figure 8-11, for example, shows

dissolved oxygen concentrations and water

temperature. The plot of the two parameters

shows that as water temperature increases

through the summer, oxygen levels generally

decline. The opposite occurs as cooler

autumn temperatures set in.

Maps and Photographs

Displaying the results of your monitoring

data on a map can be a very effective way of

helping people understand what the data

signify. A map can show the location of

sample sites in relation to features such as

cities, wastewater treatment plants, farmland,

and tributaries that may have an effect on

water quality. This type of graphic display can

be used to effectively show the correlation

between specific activities or land uses and

the impacts they have on the ecosystem.

Because a map displays the estuary’s

relationship to neighborhoods, parks, and

recreational areas, it can also help to elicit

concern for the estuary and strengthen interest

in protecting it.

There are different types of maps available.

These include:

• topographic maps, which show

natural features and elevations;

• bathymetric maps,

which show the

relief (deep and

shallow portions)

on the bottom of

estuaries;

• Geographic

Information

System (GIS)

maps, which are

computer-generated and can show

a variety of features (see box,

page 8-14);

• highway or street atlas maps;

• geologic maps; 

• soil maps;

• geologic or engineering hazards

maps;

• flood inundation maps; and 

• hand-drawn maps.

40

30

20

10

0

#1 #2 #3 #4 #5 #6

Category

Units

Figure 8-10. Line graph.

Dissolved Oxygen [mg/l]

Water Temp. [degrees C]

18

16

14

12

10

8

6

4

2

0

30

25

20

15

10

5

0

Water Temperature

Dissolved Oxygen

1-May

15-May

1-Jun

16-Jun

1-Jul

16-Jul

1-Aug

16-Aug

1-Sep

16-Sep

1-Oct

16-Oct31-Oct

Figure 8-11. Line graph comparing values for two related water quality variables.
8-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

Geographic Information Systems

Computer software systems that allow you to map and manipulate various layers of

information (such as water quality data, land use information, county boundaries, or geologic

conditions) are known as Geographic Information Systems (GIS). They can vary from simple

systems run on personal computers to sophisticated and very powerful ones that run on large

mainframes. For any GIS application, you need to know the coordinates of your sample

sites—either their latitude and longitude, or some alternate system. You can also locate your

sites on a topographic map that can be digitized onto an electronic map of the watershed.

Once these points have been established, you can link your database to the points on the map,

query your database, and create graphic displays of the data. 

Powerful GIS applications typically require expensive hardware, software, and technical

training. Any volunteer program interested in GIS applications may consider working in

partnership with other organizations such as universities, natural resource agencies, or large

nonprofit groups that can provide access to a GIS. 

Helpful Hint

Here are some tips for making your graphics easy to understand:

• Have the graph serve a clear purpose. The information contained in the graph should be relatively easy to interpret and

relate closely to the text of a document or script of a presentation. 

• Do not distort the meaning of the data. Graphical representations of the data points should be proportional to each

point’s actual value (Figure 8-12). 

• Ensure that the labeling of graphics is clear and accurate. A table of the data values should accompany any graph that is

likely to be misunderstood. 

• Keep the graphic design simple. Complex or tricky graphics often hide the true meaning of the data. Avoid cluttering the

graph with labels, arrows, grids, fill patterns, and other “visual noise” that unnecessarily complicate the graphic. Use

simple fonts that are easy to read.

• Limit the number of graphic elements. A pie chart, for example, should be divided into no more than five or six wedges.

Keep the number of superimposed lines on a line graph and the quantity of columns in a bar graph to a minimum. 

• Consider the proportions of the chart and the legibility of the type and graphic elements. A horizontal format is generally

more visually appealing, simpler to understand, and makes labels easier to read. The elements should fill the dimensions

of the graph to create a balanced effect. Ensure that the axes are labeled with legible titles and that the tick marks

showing data intervals are not crowded along the axis lines. Avoid cryptic abbreviations whenever possible,

remembering that you want your audience to fully understand the information in the graphic.

• Create a title for the chart that is simple yet informative. 

• Remember that 8 percent of the U.S. population is colorblind. When color-coding results, don’t use both red and green

on the same graphic. You may also use shapes or symbols in addition to color.

• Whether you use color, shading, or patterns, be sure that an easy-to-understand data key is included or that the data are

clearly labeled.

• If you will need to photocopy color graphics, make sure that the colors are still distinguishable when the graphics are

photocopied in black and white.

• Be consistent when comparing data; for example, don’t mix pie charts with bar graphs.

(Portions excerpted and adapted from Schoen et al., 1999.)
8-15

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

The display map should show principal

features such as roads, municipal boundaries,

waterways, and other familiar landmarks (e.g.,

schools and churches). It should have

sufficient detail and scale to show the location

of sample sites and have space for summary

information about each site. 

When displaying your data on a map,

consider the following: 

• Keep the amount of information

presented on each map to a minimum.

Do not try to put so much on one map

that it becomes visually complicated

and difficult to read or understand. A

good rule of thumb is to read the map

without referring to the legend. If the

map is not easily understood or if

symbols, lines, and colors are not

distinct from each other, then you

should use another map to display a

different layer or “view” of the data.

For example, if there are several dates

for which you wish to display

sampling results, use one map for

each date. 

• Clearly label the map and provide an

explanation of how to interpret it. If

you need a long and complicated

explanation, you may want to present

the data differently. If you have

reached a clear conclusion, state the

conclusion on the map. For example,

if a map shows that tributaries are

cleaner than the mainstem, use that

information as the subtitle of the map. 

• Provide a key to the symbols that are

used on the map. 

• Rather than packing lots of

information into a small area of the

map, use a “blowup” or enlargement

of the area elsewhere on the map to

adequately display the information. 

• Use symbols that vary in size and

pattern to represent the magnitude of

results. For example, a site with a

fecal coliform level of 10 colonies/

100 ml could be a light gray circle

with a 1/16-inch diameter while a site

with a level of 200 colonies/100 ml

would be a dark gray circle 1/4-inch

14

9

4

pH

8

7

6

5

4

Site 1 Site 2 Site 3 Site 4 Site 5

pH

50

40

30

20

10

0

TP(

μg/l)

Above

TP(

μg/l)

35

32.5

30

27.5

25

Above Golf Course Below Golf Course Below

Site 1 Site 2 Site 3 Site 4 Site 5

pH, Gooms Bay pH, Gooms Bay

Total Phosphorous, Gooms Bay Total Phosphorous, Gooms Bay

Figure 8-12. Scale considerations for presenting data. The pH graph in (a) gives the mistaken impression that the results are

similar at each site. The graph in (b) uses a narrower y-axis scale, thereby doing a better job of showing the significant differences

among monitoring sites. Changing scales to dramatize insignificant differences (c and d), however, is not recommended.

a) b)

c) d)
8-16

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

in diameter. Start

by finding the

highest and

lowest values,

assign diameters

and patterns to

those values, and

then fill in steps

along the way.

For the above

example you

might have four

ranges: 0 to 99,

100 to 199, 200 to

500, and 500+.

Photographs also

add great value to your project. Aerial photos

of the monitoring sites add a “personal

touch,” allowing citizens to see their houses

or favorite fishing spots. This can pique their

interest in the project. 

Ground-level pictures of algal blooms,

monitoring sites, and volunteers in action are

also helpful. They are qualitative records of

your estuary’s health or your monitoring

project and help your audience understand

your project and program’s activities.

Compiling a photo library is always a good

idea, especially when last-minute additions

are needed for reports, press releases, display

booths, and presentations.

Getting the Word Out

On a regular basis, a successful volunteer

estuary monitoring program should report key

findings to volunteers, data users, and the

general public, including the media. As

mentioned previously, state water quality

agencies will require detailed reports, whereas

shorter and less technical summaries are more

appropriate for the general public. 

The volunteer program should develop a

strategy for distributing and publicizing

reports. All reports should be subjected to the

review process prescribed by your quality

assurance project plan, and your program’s

leaders should be confident about the data and

comfortable with the statements and

conclusions before the report is made public.

When your report’s findings and conclusions

are released to the public, you will need to be

prepared to respond to questions regarding the

data and your interpretation of that data. 

Some ideas for distributing project results and

informing the public include the following: 

Written Report

A written document is a good instrument for

getting your information out to a wide

audience. If you have access to a mailing list of

people who are interested in your estuary, mail

the report with a cover letter that summarizes

the major findings of the study. The cover letter

should be brief and enticing so that the recipient

will be curious enough to read the report. If you

want people to take some kind of action, such

as supporting the expenditure of public funds to

upgrade a sewage treatment plant, you may

want to ask for their support in the cover letter.

If you do not have an extensive mailing list,

perhaps other organizations that share your

goals would be willing to supply you with their

lists. Be sure to also send the report to state and

federal agencies; newspapers; radio and

television stations; local libraries; colleges and

universities; research stations; and high schools,

if appropriate.

Instead of long technical reports, you may

want to develop fact sheets for public

distribution. These summaries of your findings

and conclusions should make your points

quickly and instruct the reader on how to obtain

more information.

Speaking Tour

Develop an oral presentation (with slides,

overheads, etc.) that could be offered to groups

such as the local chamber of commerce, civic

clubs, conservation organizations, schools, and

government entities. Your presentation could

even be videotaped for distribution to a wider

audience. 

A volunteer distributes information to passersby at

an Earth Day event in Washington, DC (photo by

The Ocean Conservancy).
8-17

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

Public Meetings 

Schedule a series of public meetings that

highlight the monitoring program, its findings,

and its recommendations. At the meetings,

distribute the written report, answer questions,

and tell your audience how they can get

involved. These meetings can also help you

recruit more volunteers. 

Be sure to schedule the meetings at times

when people are more likely to attend (i.e.,

weekday evenings, weekend days) and avoid

periods when people are usually busy or on

vacation. Invite the media and publicize the

meetings in newspaper calendars; send press

releases to radio and television stations,

newspapers, and other organizations; and ask

volunteers to distribute fliers at grocery

stores, city hall, etc. 

Press Releases and Press Conferences

As explained in Chapter 3, distributing a

press release is a cost-effective means of

informing the public about the results and

accomplishments of your program. Develop a

mailing list of newspapers, radio and

television stations, and organizations that

solicit articles for publication. Send the news

release to volunteers and others who are

interested in publicizing the monitoring

program.

If your report contains some real news or if

it has led to a significant event (e.g., the

mayor or city council has recognized the

value of the report and issued a statement of

support), hold a press conference (see Chapter

3 for details). 

Exhibits 

Set up displays at river festivals, county

fairs, conferences, libraries, storefront

windows, boat ramps, or parks. Exhibits allow

you to show your data to a variety of

audiences, usually in an informal setting.

Web Sites

Placing data on your program’s Web site or

the sites of project partners can be a useful

and convenient way to make your data

available. Almost everyone has access to the

Internet and developing a Web page is

relatively easy.

People curious about your project can view

the Web site for raw data, graphics, photos,

and commentary. In addition, posting

information on the site can save staff

resources that would otherwise be spent

printing and mailing the results or explaining

results over the phone.

Once people know where they can find

your data, they can continue to check the site

for updates.

Other Publicity

Be creative in getting your report and

message out. Try writing letters to the editor

or op-ed articles for local or statewide papers,

producing radio feeds (a recording of the

group’s leader played over the phone to a

radio station), issuing media advisories, and

even advertising in publications. ■
8-18

Volunteer Estuary Monitoring: A Methods Manual

Chapter 8: Data Management, Interpretation, and Presentation

Portions of this chapter were excerpted and adapted from:

Dates, G. 1995. “Interpreting Your Data.” The Volunteer Monitor 7(1).

Lease, F. 1995. “Designing a Data Management System.” The Volunteer Monitor 7(1).

Schoen, J., M-F. Walk, and M.L. Tremblay. 1999. Ready, Set, Present! A Data Presentation

Manual for Volunteer Water Quality Monitoring Groups. Massachusetts Water Watch

Partnership. Univ. of Massachusetts, Amherst. 

Web site: http://www.umass.edu/tei/mwwp/datapresmanual.html.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A

Methods Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

Other references:

Dates, G., and J. Schloss. 1998. Data to Information: A Guide for Coastal Water Quality

Monitoring Groups in New Hampshire and Maine. Univ. of Maine Cooperative Extension

and ME/NH Sea Grant. Waldoboro, ME.

Ely, E. (ed.) 1995. The Volunteer Monitor. “Special Topic: Managing and Presenting Your Data.”

7(1).

Hubbell, S. 1995. “Seize the Data.” The Volunteer Monitor 7(1).

Miller, J.K. 1995. “Data Screening and Common Sense.” The Volunteer Monitor 7(1).

Rector, J. 1995. “‘Variability Happens’: Basic Descriptive Statistics for Volunteer Programs.”

The Volunteer Monitor 7(1).

River Watch Network. 1995. Program Organizing Guide. River Watch Program of River

Network. Montpelier, VT.

Sayce, K. 1999. “Data Analysis and Presentation.” In: Meeting Notes—U.S. Environmental

Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer

Estuary Monitoring: Wave of the Future. Astoria, OR: May 19-21, 1999.

U.S. Environmental Protection Agency (USEPA). 1990. Volunteer Water Monitoring: A Guide

for State Managers. EPA 440/4-90-010. August. Office of Water, Washington, DC. 78 pp.

U.S. Environmental Protection Agency (USEPA). 1997. Proceedings—Fifth National Volunteer

Monitoring Conference: Promoting Watershed Stewardship. August 3-7, 1996, University of

Wisconsin-Madison. EPA 841-R-97-007. 

Web site: http://www.epa.gov/owow/volunteer/proceedings/toc.html.

References and Further Reading
Unit One Chemical Measures

Oxygen • Nutrients • pH and Alkalinity • Toxins
Photos (l to r): G. Carver, R. Ohrel, R. Ohrel 
Chapter 9Oxygen

Dissolved oxygen concentrations indicate how well aerated the water is, and vary

according to a number of factors, including season, time of day, temperature, and

salinity. Biochemical oxygen demand measures the amount of oxygen consumed in

the water by chemical and biological processes.
Photos (l to r) K. Register, R. Ohrel, R. Ohrel
9-1

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 9: Oxygen

Nearly all aquatic life needs oxygen to survive. Because of its importance to

estuarine ecosystems, oxygen is commonly measured by volunteer monitoring

programs. When monitoring oxygen, volunteers usually measure dissolved oxygen

and biochemical oxygen demand. 

Dissolved oxygen concentrations indicate how well aerated the water is, and

vary according to a number of factors, including season, time of day, temperature,

and salinity. Biochemical oxygen demand measures the amount of oxygen

consumed in the water by chemical and biological processes.

This chapter discusses the role of dissolved oxygen and biochemical oxygen

demand in the estuarine environment. It provides steps for measuring these water

quality variables. Finally, a case study is provided.

Overview
9-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 9: Oxygen Unit One: Chemical Measures

Of all the parameters that characterize an

estuary, the level of oxygen in the water is one

of the best indicators of the estuary’s health. An

estuary with little or no oxygen cannot support

healthy levels of animal or plant life. 

Unlike many of the problems plaguing

estuaries, the consequences of a rapid decline in

oxygen set in quickly and animals must move

to areas with higher levels of oxygen or perish.

This immediate impact makes measuring the

level of oxygen an important means of

assessing water quality. ■

Why Monitor Oxygen?

DISSOLVED OXYGEN (DO)

Oxygen enters estuarine waters from the

atmosphere and through aquatic plant photosynthesis. Currents and wind-generated waves boost

the amount of oxygen in the water by putting

more water in contact with the atmosphere. 

Dissolved Oxygen in the Estuarine

Ecosystem

DO is one of the most important factors controlling the presence or absence of estuarine

species. It is crucial for most animals and plants

except for a small minority that can survive

under conditions with little or no oxygen.

Animals and plants require oxygen for respiration—a process critical for basic metabolic

processes.

In addition to its use in respiration, oxygen is

needed to aid in decomposition. An integral part

of an estuary’s ecological cycle is the breakdown of organic matter. Like animal and plant

respiration, this process consumes oxygen.

Decomposition of large quantities of organic

matter by bacteria can severely deplete the

water of oxygen and make it uninhabitable for

many species. 

An overload of nutrients from wastewater

treatment plants or runoff from various land

uses also adds to the problem. Nutrients fuel the

overgrowth of phytoplankton, known as a

bloom. The phytoplankton ultimately die, fall to

the bottom, decompose, and use up oxygen in

the deep waters of the estuary. Although nutrients from human activities are a major cause of

depleted oxygen, low oxygen conditions may

also naturally occur in estuaries relatively unaffected by humans. Generally, however, the

severity of low DO and the length of time that

low oxygen conditions persist in these areas are

less extreme.

DO and nutrients can be connected in another

way. When oxygen is low, nutrients bound to

bottom sediments can be released into the water

column, thereby permitting more plankton

growth and eventually more oxygen depletion.

Other pollutants may also be released from sediments under low oxygen conditions, potentially

causing problems for the estuarine ecosystem. 

Oxygen availability to aquatic organisms is

complicated by the fact that its solubility in

water is generally poor. Salt water absorbs even

less oxygen than fresh water (e.g., seawater at

10°C can hold a maximum dissolved oxygen

concentration of 9.0 mg/l, while fresh water at

the same temperature can hold 11.3 mg/l).

Warm water also holds less oxygen than cold

water (e.g., seawater can hold a dissolved oxygen concentration of 9.0 mg/l at 10°C, but that

concentration drops to 7.3 mg/l when the temperature increases to 20°C). Therefore, warm

estuarine water can contain very little dissolved

oxygen, and this can have severe consequences

for aquatic organisms.

Levels of Dissolved Oxygen 

Although we may think of water as homogeneous and unchanging, its chemical constitution
9-3

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 9: Oxygen

does, in fact, vary over time. Oxygen levels, in

particular, may change sharply in a matter of

hours. DO concentrations are affected by physical, chemical, and biological factors (Figure 9-

1), making it difficult to assess the significance

of any single DO value. 

At the surface of an estuary, the water at midday is often close to oxygen saturation due both

to mixing with air and the production of oxygen

by plant photosynthesis (an activity driven by

sunlight). As night falls, photosynthesis ceases

and plants consume available oxygen, forcing DO

levels at the surface to decline. Cloudy weather

may also cause surface water DO levels to drop

since reduced sunlight slows photosynthesis. 

DO levels in an estuary can fluctuate greatly

with depth, especially during certain times of

the year. Temperature differences between the

surface and deeper parts of the estuary may be

quite distinct during the warmer months.

Vertical stratification in estuarine waters

(warmer, fresher water over colder, saltier

water) during the late spring to summer period

is quite effective in blocking the transfer of

oxygen between the upper and lower layers (see

Figure 9-1). In a well-stratified estuary, very little oxygen may reach lower depths and the

deep water may remain at a fairly constant low

level of DO. Changing seasons or storms, however, can cause the stratification to disintegrate,

allowing oxygen-rich surface water to mix with

the oxygen-poor deep water. This period of

mixing is known as an overturn.

When DO declines below threshold levels,

which vary depending upon the species, mobile

animals must move to waters with higher DO;

immobile species often perish. Most animals

and plants can grow and reproduce unimpaired

when DO levels exceed 5 mg/l. When levels

drop to 3-5 mg/l, however, living organisms

often become stressed. If levels fall below 3

mg/l, a condition known as hypoxia, many

species will move elsewhere and immobile

species may die. A second condition, known

as anoxia, occurs when the water becomes

totally depleted of oxygen (below 0.5 mg/l)

and results in the death of any organism that

requires oxygen for survival. Figure 9-2 summarizes DO thresholds in estuarine waters. ■

Sewage effluent

Phytoplankton bloom

thrives on nutrients

DO from wave action

& photosynthesis

Lighter freshwater

Heavier seawater

DO trapped

in lighter layer

Decomposition

DO used up by

microorganism respiration

Nutrients released

by bottom sediments

DO Consumed

Fish able to

avoid hypoxia

Decomposition of organic

matter in sediments

Shellfish

unable to

escape

hypoxia

Dead material

settles

Runoff

HYPOXIA

Figure 9-1. Physical, chemical, and biological processes that affect dissolved

oxygen concentrations in estuaries. (Redrawn from USEPA, 1998.)

5 mg/l

3 mg/l

0 mg/l

4 mg/l

2 mg/l

1 mg/l

6 mg/l

DO Concentration (mg/l)

Usually required for

growth and activity

Stressful to most aquatic

organisms

Usually will not

support fish

hypoxia

anoxia

Figure 9-2. Dissolved oxygen in the water. A minimum DO concentration

of 5 mg/l is usually necessary to fully support aquatic life.
9-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 9: Oxygen Unit One: Chemical Measures

Chapter 6 summarized several factors that

should be considered when determining

monitoring sites, where to monitor in the water

column, and when to monitor. In addition to the

considerations in Chapter 6, a few additional

ones specific to oxygen monitoring are

presented here.

When to Sample 

In estuarine systems, sampling for DO

throughout the year is preferable to establish a

clear picture of water quality. If year-round

sampling is not possible, taking samples from

the beginning of spring well into autumn will

provide a program with the most significant

data. Warm weather conditions bring on

hypoxia and anoxia, which pose serious

problems for the estuary’s plants and animals.

Because these conditions are rare during winter,

cold weather data can serve as a baseline of

information. 

Sampling once a week is

generally sufficient to capture the

variability of DO in the estuary.

Since DO may fluctuate

throughout the day, volunteers

should sample at about the same

time of day each week. This way,

they are less likely to record data

that largely capture daily

fluctuations. Some programs

suggest that

volunteers

sample in the

morning near

dawn as well as

mid-afternoon to

capture the daily

high and low 

DO values. 

In some areas,

especially large

tidal swings can

work to weaken

the stratification

in the estuary. Tidal effects, then, could be a

consideration when collecting and analyzing

DO data.

Where to Sample

As mentioned previously, estuary

stratification can have an impact on DO levels

at different depths. Stratification is especially

evident during the summer months, when warm

fresh water overlies colder, saltier water. Very

little mixing occurs between the layers, forming

a boundary to mixing. 

Because DO levels vary with depth—

especially during the summer—volunteer

groups may wish to collect samples at different

depths. Van Dorn and Kemmerer samplers (see

Chapter 7) are commonly used to collect these

kinds of samples. In addition, there are several

water samplers designed primarily for

collecting DO samples at different depths

(Figure 9-3). Appendix C provides a list of

equipment suppliers.

Choosing a Sampling Method

Citizen programs may elect to use either a

DO electronic meter or one of the several

available DO test kits (Table 9-1). If the

volunteer group wants its data to be used 

by state or federal agencies, it is wise to

confer with the appropriate agency

beforehand to determine an acceptable

monitoring method.

Meters

The electronic meter measures DO based on

the rate of molecular oxygen diffusion across a

membrane. The results from a DO meter are

extremely accurate, providing the unit is wellmaintained, calibrated, and the membrane is

handled in accordance with the manufacturer’s

instructions before each use. To properly

calibrate some DO meters, knowledge of the

sampling site’s salinity is necessary.

The DO probe may be placed directly into

Sampling Considerations 

Figure 9-3. Dissolved oxygen samplers. Many of these

instruments may also be used to collect samples for the

analysis of other water quality variables.
9-5

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 9: Oxygen

the estuary for a reading or into a water sample

drawn out by bucket for a surface

measurement. Depending on the length of its

cable, a meter may allow monitors to get DO

readings directly from various depths. Some

meters allow volunteers to take both DO and

temperature readings simultaneously.

Though easy to use, a reliable DO meter will

likely cost more than $1,000. It also uses

batteries, which last a long time but must be

disposed of properly. To offset upfront and

maintenance costs, monitoring groups might

consider sharing equipment (Stancioff, 1996). 

Because of the expense, a volunteer program

might be able to afford only one meter.

Consequently, only one team of monitors can

measure DO and they will have to do it at all

sites. Dissolved oxygen meters may be useful

for programs in which many measurements are

needed at only a few sites, volunteers sample at

several sites by boat, or volunteers plan on 

running DO profiles (many measurements

taken at different depths at one site). 

Test Kits

If volunteers are sampling at several widely

scattered sites, one of the many DO kits on the

market may be more cost-effective. These kits

rely on the Winkler titration method or one of

its modifications. The modifications reduce the

effect of materials in the water, such as organic

matter, which may cause inaccurate results. 

The kits are inexpensive, generally ranging

from $30 to $200, depending on the method of

titration they use. While inexpensive upfront,

the kits require reagent refills as the reagents

are used up or degrade over time. Reagents cannot be reused. Unused reagents and waste generated during the performance of tests must be

disposed of properly (see Chapter 7).

Volunteers must also take appropriate safety

precautions when using the reagents, which can

be harmful if used improperly.

Kits provide good results if monitors adhere

strictly to established sampling protocols.

Aerating the water sample, allowing it to sit in

sunlight or unfixed (see box, page 9-6, for an

explanation of fixing), and titrating too hastily

can all introduce error into DO results. 

For convenience, the volunteer monitors may

keep their kits at home and take them to the

sampling site each week. The program manager

must provide the monitors with fresh chemicals

as needed. Periodically, the manager should

check the kit to make sure that each volunteer is

properly maintaining and storing the kit’s

components. At the start of the monitoring

program, and periodically thereafter if possible,

the program manager should directly compare

kit measurements to those from a standard

Winkler titration conducted in a laboratory. ■

Method Location of Comments

Measurement

Meter

Test kit 

(Winkler

titration)

Field

Field or Lab

• The meter must be properly calibrated,

accounting for salinity.

• The meter is fragile; handle it carefully.

• If measured in lab, the sample is fixed in the

field and titrated in the lab.

• Lab measurement must take place within 8 hours

of sample collection.

Table 9-1. Summary of dissolved oxygen monitoring methods. Depending on the method used, DO

measurements may be made in the field or in a laboratory (USEPA, 1997).
Reminder!

To ensure consistently high quality data, appropriate quality control measures are necessary.

See “Quality Control and Assessment” in Chapter 5 for details.

Not all quality control procedures are appropriate for all water quality analyses. Blanks and

standards are not usually used for Winkler DO titrations, due to problems with contamination

by oxygen from the air. To check the accuracy of the procedure, one has at least two options:

• Create an oxygen-saturated sample by shaking and pouring water back and forth through

the air, then titrate the sample and compare the results to published tables of oxygen

solubility versus temperature (salinity must be known to determine oxygen solubility).

• Use a standard solution of potassium bi-iodate to check the accuracy of the titrant

(standard solutions can be ordered from chemical supply companies—see Appendix C).

The amount of titrant required to make the sample colorless should equal the amount of

potassium bi-iodate added to the sample, +

–0.1 ml. 

(Excerpted and adapted from Mattson, 1992.)

9-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 9: Oxygen Unit One: Chemical Measures

Titration 

Titration is an analytical procedure used to measure the quantity of a substance in a water

sample by generating a known chemical reaction. In the process, a reagent is

incrementally added to a measured volume of the sample until reaching an obvious

endpoint, such as a distinct change in color (Figure 9-4). 

Volunteers can use titration to assess the

quantity of dissolved oxygen at a sampling site.

This procedure, known as the Winkler titration,

uses iodine as a substitute for the oxygen

dissolved in a “fixed” sample of water. A fixed

sample is one in which the water has been

chemically rendered stable or unalterable,

meaning that atmospheric oxygen will no

longer affect the test result. Iodine stains the

sample yellow-brown. Then, a chemical called

sodium thiosulfate reacts with the free iodine in

the water to form another chemical, sodium

iodide. When the reaction is complete, the

sample turns clear. This color change is called

the endpoint. 

Since the color change is often swift and can occur between one drop of reagent and the

next, a starch indicator should be added to the solution to exaggerate the color change.

The starch keeps the sample blue until all the free iodine is gone, at which time the

sample immediately turns colorless. The amount of sodium thiosulfate used to turn the

sample clear translates directly into the amount of dissolved oxygen present in the

original water sample. 

20 ml

Figure 9-4.

Titration of a

reagent into a

water sample.

The volunteer on the left is titrating a water

sample, while the other volunteer is “fixing”

another sample (photo by K. Register).
9-7

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 9: Oxygen

How to Monitor Dissolved Oxygen

General procedures for collecting and

analyzing dissolved oxygen samples are

presented in this section for guidance only; they

do not apply to all sampling methods.

Monitors should consult with the

instructions that come with their sampling

and analyzing instruments. Those who are

interested in submitting data to water

quality agencies should also consult with the

agencies to determine acceptable equipment,

methods, quality control measures, and data

quality objectives (see Chapter 5).

Before proceeding to the monitoring site and

collecting samples, volunteers should review

the topics addressed in Chapter 7. It is critical

to confirm the monitoring site, date, and time;

have the necessary monitoring equipment and

personal gear; and understand all safety

considerations. Once at the monitoring site,

volunteers should record general site

observations, as discussed in Chapter 7.

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site for each sampling session: 

If using the Winkler method

• large clean bucket with rope (if taking

surface sample or if unable to collect

sample directly in DO bottles);

• Kemmerer, Van Dorn, DO sampler, or

homemade sampler (if taking a full DO

profile);

• fully stocked dissolved oxygen kit with

instructions;

• extra DO bottles;

• equipment for measuring temperature and

salinity (necessary to calculate percent

saturation—see page 9-12); and

• enough reagents for the number of sites to

be tested.

If using a meter and probe

• calibrated DO meter and probe with

operating manual (the meter must be

calibrated according to the

manufacturer’s instructions);

• extra membranes and electrolyte

solution for the probe;

• extra batteries for the meter;

• extra O-rings for the membrane;

• extension pole; and

• equipment for measuring temperature

and salinity (necessary to calculate

percent saturation—see page 9-12), 

if temperature and salinity cannot be

measured by the meter.

STEP 2: Collect the sample.

This task is necessary if the volunteer is

using a DO kit or if a sample is being drawn

for a DO meter (rather than placing the DO

probe directly in the estuary). Chapter 7

reviews general information about collecting a

water sample. 

Although the task of collecting a bottle of

water seems relatively easy, volunteers must

follow strict guidelines to prevent

contamination of the sample. The citizen

monitor must take care during collection of

the water; jostling or swirling the sample can

result in aeration and cause erroneous data.

Using a bucket to collect the sample increases

the risk of introducing oxygen to the sample.

It is preferable to use a standard DO sampling

bottle rather than a simple bucket since a

washed and capped bottle is less likely to

become contaminated than an open container.
9-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 9: Oxygen Unit One: Chemical Measures

Reminder!

The water sample must be collected in such

a way that you can cap the bottle while it is

still submerged. That means you must be

able to reach into the water with both arms

and the water must be deeper than the

sample bottle.

If using a bucket

• Rinse the sample bucket with estuary

water twice before sampling. Rinse and

empty the bucket away from the

collection area. 

• Drop the bucket over the side of the

dock, pier, or boat and allow water from

just under the surface to gently fill the

container until it is about two-thirds full.

There should be no air bubbles in the

bucket. 

• Lift the bucket carefully to the working

platform. 

• If using a DO kit, rinse two DO bottles

twice each with estuary water before

filling them from the sample bucket.

Then, submerge each capped bottle in

the bucket, remove the lid, and slowly

fill. Avoid agitating the water in the

bucket to minimize the introduction of

oxygen to the sample. 

• While the bottle is

still under water,

tap its side to

loosen any air

bubbles before

capping and lifting

the bottle from the

bucket. 

• Check the sample

for bubbles by

turning the bottle

upside-down and

tapping. 

If you see any

bubbles, repeat the 

filling steps.

If collecting samples directly in bottles

• Rinse two DO bottles twice each with

estuary water away from the collection

area before filling them with the sample.

• Make sure you are positioned

downcurrent of the bottle.

• Submerge each capped bottle in the

water, facing into the current.

• Remove the lid, and slowly fill (Figure 9-

5). Avoid agitating the water to minimize

the introduction of oxygen to the sample. 

• While the bottle is still under water, tap

its side to loosen any air bubbles before

capping and lifting the bottle from the

water. 

• Check the sample for bubbles by turning

the bottle upside-down and tapping. If you

see any bubbles, repeat the filling steps.

If collecting samples from other samplers

• Follow the manufacturer’s instructions.

• Make sure that no air bubbles are

introduced into the sample.

• The sampler should have a mechanism

for allowing the DO bottle to fill from the

bottom to the top.

If using a test kit, take the water temperature

by setting the thermometer in the bucket and

allow it to stabilize while preparing for the DO

test. Most meters will have a thermometer

included. The bucket of water used for

measuring DO can also be used for many of the

other water quality tests. 

Temperature and salinity should also be

measured to calibrate a DO meter or if the

volunteer group wishes to calculate percent

saturation (see box, page 9-12).

STEP 3: Measure DO.

Many citizen monitoring programs use the

“azide modification” of the Winkler titration 

to measure DO. This test removes interference

due to nitrites—a common problem in 

estuarine waters. 

Figure 9-5. Taking a water sample for DO analysis.

Point the bottle against the tide or current and fill

gradually. Cap the bottle under water when full,

ensuring that there are no air bubbles in the bottle

(USEPA, 1997).
9-9

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 9: Oxygen

If using the Winkler method

Gloves should be worn when doing this test.

Part One: “Fix” the sample immediately

• Proceed with the DO test for both

sample bottles by carefully following

the manufacturer’s instructions. Allow

some of the sample to overflow during

these steps; this overflow assures that no

atmospheric oxygen enters the bottled

contents. After the sample is fixed,

exposure to air will not affect the

oxygen content of the sample. Be

careful not to introduce air into the

sample while adding the reagents.

Simply drop the reagents into the test

sample, cap carefully, and mix gently.

• Once the sample has been fixed in this

manner, it is not necessary to perform

the titration procedure immediately.

Thus, several samples can be collected

and “fixed” in the field, then carried

back to a testing station or laboratory

where the titration procedure is to be

performed. The titration portion of the

test should be carried out within 8

hours. In the meantime, keep the sample

refrigerated and in the dark.

Part Two: Titrating the sample

• Continue with the titration of both

samples, again following specific

instructions included with the kit or

provided by the program manager. 

• Carefully measure the amount of fixed

sample used in titration; this step is

critical to the accuracy of the results.

The bottom of the meniscus should rest

on top of the white line on the titration

test tube. (A meniscus is the curved

upper surface of a liquid column that is

concave when the containing walls are

wetted by the liquid—see Figure 9-6.)

• Fill the syringe in the test kit, following

instructions.

• Insert the syringe into

the hole on top of the

test tube and add 1 drop

of sodium thiosulfate to

the test tube; swirl the

test tube to mix. Add

another drop of the

sodium thiosulfate and

swirl the tube. Continue

this titration process one

drop at a time until the

yellow-brown solution

in the test tube turns a

pale yellow. Then pull

the syringe out of the

hole (with the remaining

sodium thiosulfate) and

put it aside for a moment.

• Add starch solution to the test tube

through the hole on top of the lid,

according to directions. Swirl the tube to

mix. The solution should turn from light

yellow to dark blue.

• Now put the syringe back into the hole

on the test tube. Continue the titration

process with the remaining sodium

thiosulfate, until the test tube solution

turns from blue to clear. Do not add any

more sodium thiosulfate than is

necessary to produce the color change.

Be sure to swirl the test tube after each

drop.

• Using the scale on the side of the

syringe, read the total number of units of

sodium thiosulfate used in the

experiment. Each milliliter of thiosulfate

used is equivalent to 1 mg/l DO. 

• Each volunteer should carry out all steps

on two samples to minimize the

possibility of error. The two samples can

either be titrated from the one bottle of

fixed sample solution or, for better

quality assurance, from two water

samples fixed in the field. 

Test Tube Read

Here

Meniscus

Figure 9-6. Measurements should be

made at the bottom of the meniscus.
9-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 9: Oxygen Unit One: Chemical Measures

• If the discrepancy between the two DO

concentrations is significant, the

volunteer should run a third titration.

The program’s quality assurance project

plan should define what difference is

considered “significant.” Some

monitoring programs stipulate that a

third sample must be analyzed if the DO

concentrations of the first two samples

differ by more than 0.6 mg/l.

NOTE: Samples with high levels of DO are

brown, while low DO samples are generally

pale yellow before the starch indicator is

added. A few minutes after reaching the

colorless endpoint, the sample may turn blue

once again. This color reversion is not cause

for concern—it is simply proof of a precise

titration.

Helpful Hint

If volunteers are to collect and fix two water

samples at each of their monitoring sites,

be sure to provide each monitor with the

appropriate number of DO bottles (e.g., 4

bottles for 2 monitoring sites, etc.). The

bottles can be permanently marked with site

location names. Volunteers will collect and

fix the samples in the field, then titrate the

samples within 8 hours. After the DO

bottles have been emptied and cleaned,

they are ready for the next monitoring

session.

If using a meter and probe

• Make sure the unit is calibrated

according to the manufacturer’s

instructions. Knowledge of salinity is

needed to properly calibrate most meters

(Green, 1998). 

• After inserting the DO probe into the

bucket or placing it over the side of the

boat or pier, allow the probe to stabilize

for at least 90 seconds before taking a

reading. 

• With some meters, you should manually

stir the probe without disturbing the

water to get an accurate measurement. 

STEP 4: Clean up and submit data.

If using the Winkler titration method, make

sure to thoroughly rinse all glassware in the

kit and tightly screw on the caps to the

reagent bottles. Check to ensure that each

bottle contains sufficient reagents for the next

DO analysis. Properly dispose of wastes

generated during the performance of tests (see

Chapter 7).

If using a laboratory to analyze the samples,

deliver the fixed samples and field data sheets

to the lab as soon as possible, as the sample

analysis must be done within 8 hours. 

Make sure that the data sheet is complete

and accurate. Volunteers should make a copy

of the completed data sheet before forwarding

it to the project manager in case the original

data sheet becomes lost. ■
9-11

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 9: Oxygen

Case Study: 

Dissolved Oxygen Monitoring in New Jersey

In New Jersey, the Alliance for a Living Ocean coordinates the Barnegat Bay Watch Monitoring

Program. Dissolved oxygen testing is one of the more complicated monitoring activities undertaken by program volunteers.

The volunteer monitors use a modified Winkler titration test kit that is user-friendly and has a

good degree of accuracy. With each test kit, the monitors receive a test procedure sheet and a

monitor’s testing manual. Often, monitors tape a simplified version of the test procedures to the

inside of their test kits.

The program provides several tips to minimize any confusion about the test procedure:

• Because the test kit uses five reagents, monitors are encouraged to label the reagent bottles as #1, #2, etc. 

• It is suggested that the bottles be arranged in numeric order in the test kit. This simplifies

looking for the next reagent. 

• Solutions 1, 2, 3, and 5 are each added 8 drops at a time. (Solution #4 is added one drop

at a time.) The monitors can mark these reagent bottles with the words “8 drops.” When

the monitors’ hands are wet or the wind is blowing, it is much easier to read the label on a

bottle than an instruction sheet.

Many monitors conduct tests from their boats in the Barnegat Bay. These monitors are encouraged to “fix” the water sample by adding the first three reagents, and then return to land. Once

on shore, volunteers can resume the test, which includes filling a titration tube to exactly 20 ml

and titrating Solution #4 one drop at a time. In this manner, inaccuracies caused by a rocking

boat are avoided.

Monitors are reminded to remove all air bubbles from the water sample by tapping the sample

bottle while it is submerged. Monitors also double-check for air bubbles in the sample and the

titration plunger before beginning a test. Air bubbles in the plunger are avoided by depressing

the plunger before drawing up the titration solution. These practices greatly reduce data error.

The program suggests that volunteers perform the dissolved oxygen test several times at home

or in the laboratory before going out in the field. Through practice, they can become familiar

with the order of reagents and what the water sample should look like at each step. 

For More Information:

Alliance for a Living Ocean

P.O. Box 95

Ship Bottom, NJ 08008

Phone: 609-492-0222

Fax: 609-492-6216

E-mail: livingocean@worldnet.att.net
9-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 9: Oxygen Unit One: Chemical Measures

DO saturation, or potential DO level,

refers to the highest DO concentration

possible under the environmental limits of

temperature, salinity (or chlorinity), and

atmospheric pressure. As salinity or

chlorinity increases, the amount of

oxygen that water can hold decreases

substantially. For example, at 20°C, 100%

DO saturation for fresh water (for which

salinity and chlorinity are zero) is 9.09

mg/l. At the same temperature, 100%

saturation for water with 36 parts per

thousand (ppt) salinity is 7.34 mg/l. 

Table 9-2 summarizes DO saturation

levels for different salinities and

temperatures at sea level. Tables showing

saturation levels in waters of various

chlorinity can be found in APHA (1998).

Percent saturation is the amount of

oxygen in the water relative to the water’s

potential DO saturation. It is calculated as

follows:

Percent saturation = measured DO x 100

DO saturation

(Excerpted and adapted from Green, 1998.)

Table 9-2. Dissolved oxygen saturation

concentrations (mg/l) in waters of various salinity

(ppt) and temperature (°C ) at sea level (adapted

from Campbell and Wildberger, 1992, and APHA,

1998). Readers are referred to APHA (1998) for

DO saturation concentrations using chlorinity

instead of salinity (salinity = 1.80655 x

chlorinity). 

0.0 14.6 13.7 12.9 12.1 11.4

1.0 14.2 13.4 12.5 11.8 11.1

2.0 13.8 13.0 12.2 11.5 10.8

3.0 13.5 12.7 11.9 11.2 10.5

4.0 13.1 12.3 11.6 10.9 10.3

5.0 12.8 12.0 11.3 10.6 10.0

6.0 12.4 11.7 11.0 10.4 9.8

7.0 12.1 11.4 10.8 10.2 9.6

8.0 11.8 11.2 10.5 9.9 9.4

9.0 11.6 10.9 10.3 9.7 9.2

10.0 11.3 10.6 10.0 9.5 9.0

11.0 11.0 10.4 9.8 9.3 8.8

12.0 10.8 10.2 9.6 9.1 8.6

13.0 10.5 10.0 9.4 8.9 8.4

14.0 10.3 9.7 9.2 8.7 8.2

15.0 10.1 9.5 9.0 8.5 8.1

16.0 9.9 9.3 8.8 8.4 7.9

17.0 9.7 9.2 8.7 8.2 7.8

18.0 9.5 9.0 8.5 8.0 7.6

19.0 9.3 8.8 8.3 7.9 7.5

20.0 9.1 8.6 8.2 7.7 7.3

21.0 8.9 8.4 8.0 7.6 7.2

22.0 8.7 8.3 7.9 7.5 7.1

23.0 8.6 8.1 7.7 7.3 7.0

24.0 8.4 8.0 7.6 7.2 6.8

25.0 8.3 7.8 7.4 7.1 6.7

26.0 8.1 7.7 7.3 7.0 6.6

27.0 8.0 7.6 7.2 6.8 6.5

28.0 7.8 7.4 7.1 6.7 6.4

29.0 7.7 7.3 7.0 6.6 6.3

30.0 7.6 7.2 6.8 6.5 6.2

31.0 7.4 7.1 6.7 6.4 6.1

32.0 7.3 7.0 6.6 6.3 6.0

33.0 7.2 6.8 6.5 6.2 5.9

34.0 7.1 6.7 6.4 6.1 5.8

35.0 7.0 6.6 6.3 6.0 5.7

Temperature 

°C Salinity: 0 ppt 9 ppt 18 ppt 27 ppt 36 ppt

Oxygen Saturation Concentration (mg/l)

DO Saturation and Percent Saturation
9-13

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 9: Oxygen

Should I pour off any of the water in my sample bottle before I add the reagents?

No. Pouring off some of the water allows space for an air bubble to be trapped when the

bottle is capped. When you shake the bottle, this oxygen mixes with the sample and causes

erroneously high results. It’s OK for some liquid to overflow as you add the fixing reagents.

(If you are concerned about spillage, put the bottle on a paper towel.) 

How should I hold the dropper bottles to dispense the reagents? 

Hold the dropper bottles completely upside down (i.e., vertical). This ensures a uniform drop

size. 

What is meant by saying that the sample is “fixed”? 

After the first three reagents are added, the sample is fixed; this means that contact with

atmospheric oxygen will no longer affect the test result because all the dissolved oxygen in the

sample has reacted with the added reagents. The final titration actually measures iodine instead

of oxygen. Fixed samples may be stored up to 8 hours, if kept refrigerated and in the dark.

What if I spill some of the acid as I am fixing the sample?

As part of the fixing process, acid crystals or liquid are added to the sample. The addition of

the acid will dissolve the flocculate. You can spill a few acid crystals and not have to start

over—but you should be sure to clean up the spill (see Chapter 7). If a few grains of acid do

not go into the solution and all the flocculate is dissolved, you may continue the titration. 

Sometimes after I add the acid, some brown “dots” remain. Is this OK? 

The brown particles should be dissolved before you continue the test. Try shaking the sample

bottle again. If this doesn’t work, add one more drop of acid. You may occasionally find that

organic material or sediment in the sample will not dissolve. This will not affect the test results. 

What if my sample is colorless after it’s fixed? 

This means there is no dissolved oxygen in the sample. If this happens, you might want to

test a sample that you know contains oxygen to make sure that your kit is functioning

properly. One way to do this is to intentionally introduce an air bubble into the water

sample, shake well, then fix the sample. You should see a yellow color.

When filling the syringe with the thiosulfate reagent, how far back should I pull the barrel?

The point of the black neoprene tip should be set right at zero. This is extremely important.

What if my syringe runs out of the sodium thiosulfate titrant?

In colder water, the amount of DO may be above 10 mg/l, so you will have to refill the

syringe. For accurate results, fill to 0 mark and add the amount titrated from second syringefull to the 10 from the first syringe-full.

How much starch solution should I add?

When and how much starch solution is added is not critical to the test. The important thing is

that the sample turns blue.

Common Questions About DO Testing 

(Excerpted and adapted from Green, 1997, and Ellett, 1993.) 
9-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 9: Oxygen Unit One: Chemical Measures

Biochemical oxygen demand measures the

amount of oxygen that microorganisms

consume while decomposing organic matter;

it also measures the chemical oxidation of

inorganic matter (i.e., the extraction of

oxygen from water via chemical reaction).

The rate of oxygen consumption in an estuary

is affected by a number of variables, including

temperature, the presence of certain kinds of

microorganisms, and the type of organic and

inorganic material in the water.

The Role of Biochemical Oxygen Demand

in the Estuarine Ecosystem

BOD directly affects the amount of dissolved

oxygen in estuaries. The greater the BOD, the

more rapidly oxygen is depleted. This means

less oxygen is available to aquatic organisms.

The consequences of high BOD are the same as

those for low dissolved oxygen: many aquatic

organisms become stressed, suffocate, and die.

Examples of BOD levels are provided in Table

9-3. Sampling locations with traditionally high

BOD are often good candidates for more

frequent DO sampling.

Table 9-3. Significant BOD Levels (from

Campbell and Wildberger, 1992).

*Allowable level for individual treatment plant

specified in discharge permit

Sources of BOD include leaves and 

woody debris; dead plants and animals; 

animal waste; effluents from pulp and paper

mills, wastewater treatment plants, feedlots,

and food-processing plants; failing septic

systems; and urban stormwater runoff.

Although some waters are naturally organicrich, a high BOD often indicates polluted or

eutrophic waters. ■

Type of Water BOD (mg/l)

unpolluted, natural water <5

raw sewage 150-300

wastewater treatment 8-150*

plant effluent

BIOCHEMICAL OXYGEN DEMAND (BOD)

Sampling Considerations

BOD is affected by the same factors that

affect DO. Chlorine can also affect BOD

measurements by inhibiting or killing the

microorganisms that decompose the organic

and inorganic matter in a sample. In some

water samples, chlorine will dissipate within

1-2 hours of being exposed to light. Such

exposure often happens during sample

handling or transport. However, if you are

sampling in heavily chlorinated waters, such

as those below the effluent discharge point

from a wastewater treatment plant, it may be

necessary to neutralize the chlorine with

sodium thiosulfate (see APHA, 1998). ■
9-15

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 9: Oxygen

The standard BOD test is a simple means of

measuring the uptake of oxygen in a sample

over a predetermined period of time. Citizens

can easily collect the required water samples

as they monitor the water for other variables.

The BOD test does, however, demand a

several-day period of water storage in the

dark to obtain results. Test for BOD using the

following steps:

• Collect two water samples from the

same place in the water column (surface

or at depth) using the water sampling

protocol described earlier for DO. Each

bottle should be labeled clearly so that

the samples will not be confused. Make

sure there is no contact between the

sample water and the air.

• Immediately measure the first sample

for DO using either a DO meter or DO

kit. Record the time of sample

collection and the water temperature.

Place the second sample in a standard

BOD bottle. The bottle should be black

to prevent photosynthesis. You can wrap

a clear bottle with black electrician’s

tape, aluminum foil, or black plastic if

you do not have a black or brown glass

bottle.

• Incubate the bottle of untested sample

water at 20o

C and in total darkness (to

prevent photosynthesis). After 5 days of

incubation, use the same method of

testing to measure the quantity of DO in

the second sample. Because of the 5-day

incubation, the test should be conducted

in a laboratory.

• The BOD is expressed in milligrams per

liter of DO using the following

equation:

BOD = DO (mg/l) of 1st bottle – DO of 2nd bottle 

This represents the amount of oxygen

consumed by microorganisms to break down

the organic matter present in the sample bottle

during the incubation period. 

Sometimes by the end of the 5-day

incubation period, the DO level is zero. This

is especially true for monitoring sites with a

lot of organic pollution (e.g., downstream of

wastewater discharges). Since it is not known

when the zero point was reached, it is not

possible to tell what the BOD level is. In this

case, it is necessary to collect another sample

and dilute it by a factor that results in a final

DO level of at least 2 mg/l. Special dilution

water containing the nutrients necessary for

bacterial growth should be used for the

dilutions. Some supply houses carry

premeasured nutrient “pillows” to simplify the

process. APHA (1998) describes in detail how

to dilute a sample and conduct the BOD

analysis.

It takes some experimentation to determine

the appropriate dilution factor for a particular

sampling site. The final result is the difference

in DO between the first measurement and the

second after multiplying the second result by

the dilution factor. ■

How to Measure Biochemical Oxygen Demand
9-16

Volunteer Estuary Monitoring: A Methods Manual

Chapter 9: Oxygen Unit One: Chemical Measures

Portions of this chapter were excerpted and adapted from:

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A

Methods Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

Other references:

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L.S. Clesceri, A.E. Greenberg, A.D. Eaton (eds). Washington, DC.

Campbell, G., and S. Wildberger. 1992. The Monitor’s Handbook. LaMotte Company,

Chestertown, MD. 71 pp.

Ellett, K. 1993. Chesapeake Bay Citizen Monitoring Program Manual. Alliance for the

Chesapeake Bay. Richmond, VA. 57 pp.

Green, L. 1997. “Common Questions About DO Testing.” The Volunteer Monitor 9(1).

Green, L. 1998. “Let Us Go Down to the Sea—How Monitoring Changes from River to

Estuary.” The Volunteer Monitor 10(2): 1-3.

Mattson, M. 1992. “The Basics of Quality Control.” The Volunteer Monitor 4(2): 6-8.

Stancioff, E. 1996. Clean Water: A Guide to Water Quality Monitoring for Volunteer Monitors of

Coastal Waters. Maine/New Hampshire Sea Grant Marine Advisory Program and University

of Maine Cooperative Extension. Orono, ME. 73 pp.

U.S. Environmental Protection Agency (USEPA). 1998. Condition of the Mid-Atlantic Estuaries.

EPA 600-R-98-147. November. Office of Research and Development, Washington, DC. 

50 pp.

References and Further Reading
Chapter 10 Nutrients

Nutrients—especially nitrogen and phosphorus—are key water quality parameters

in estuaries. Nutrient concentrations vary according to surrounding land use,

season, and geology. Because nitrogen and phosphorus play such important roles

in the estuarine ecosystem, it is not surprising that volunteer groups very

commonly monitor these two nutrients.
Photos (l to r): K. Register, R. Ohrel, The Ocean Conservancy, E. Ely
10-1

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 10: Nutrients

Nutrients—especially nitrogen and phosphorus—are key water quality

parameters in estuaries. Depending on their chemical forms (or species), nitrogen

and phosphorus can have significant direct or indirect impacts on plant growth,

oxygen concentrations, water clarity, and sedimentation rates, just to name a few.

Nitrogen’s primary role in organisms is protein and DNA synthesis; plants also

use this substance in photosynthesis. Phosphorus is critical for metabolic

processes, which involve the transfer of energy. Because nitrogen and phosphorus

play such important roles in the estuarine ecosystem, it is not surprising that

volunteer groups very commonly monitor these two nutrients.

Nutrient concentrations vary according to surrounding land use, season, and

geology. This chapter discusses factors that the volunteer monitor should consider

when establishing a nutrient monitoring program. Sample monitoring instruments

and techniques are described. Finally, an additional monitoring opportunity for

volunteers—atmospheric deposition—is introduced.

Overview
10-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 10: Nutrients Unit One: Chemical Measures

Nutrients are chemical substances used for

maintenance and growth that are critical for

survival. Plants require a number of

nutrients—carbon, nitrogen, phosphorus,

oxygen, silica, magnesium, potassium,

calcium, iron, zinc, and copper—to grow,

reproduce, and ward off disease. Of these

nutrients, nitrogen and phosphorus are of

particular concern in estuaries for two

reasons:

• they are two of the most important

nutrients essential for the growth of

aquatic plants; and 

• the amount of these nutrients being

delivered to estuaries has increased

significantly. 

Eutrophication is a condition in which

high nutrient concentrations stimulate excessive algal blooms, which then deplete

oxygen as they decompose (Figure 10-1). 

The organic production can also lead to

sediment accumulation. Because of the

potential impacts of nutrients, citizen monitoring programs often focus on nitrogen and

phosphorus as indicators of estuarine health.

Nutrient Sources

Nitrogen and phosphorus enter estuaries

from several natural and human-made sources

(Figure 10-2). Natural sources of nitrogen and

phosphorus in the estuary include:

• fresh water that runs over geologic

formations rich in phosphate or nitrate;

• decomposing organic matter and

wildlife waste; and 

• the extraction of nitrogen gas from the

atmosphere by some bacteria and bluegreen algae (known as nitrogen

fixation).

There are three major manmade or

anthropogenic sources of nutrients:

atmospheric deposition, surface water, and

groundwater. Atmospheric sources include

fossil fuel burning by power plants and

automobiles. Nutrients from these sources

may fall to the land or estuary either directly

or along with precipitation. Surface water

inputs include point and nonpoint source

discharges: effluent from wastewater

treatment plants, urban stormwater runoff,

lawn and agricultural fertilizer

runoff, industrial discharges, and

livestock wastes. Groundwater

sources are primarily underwater

seepage from agricultural fields

and failing septic systems.

The Role of Nutrients in the

Estuarine Ecosystem

Figures 10-3 and 10-4 illustrate

the nitrogen and phosphorus

cycles, respectively. Although

nutrients are essential for the

growth and survival of an

estuary’s plants, an excess of

nitrogen and phosphorus may

trigger a string of events that

seasonally deplete dissolved

Why Monitor Nutrients?

Estuary A Estuary B

0 5 10 5 0

DO, mg/l

Figure 10-1. Eutrophication. Estuary B receives more nutrient loads than Estuary A. As a

result, Estuary B experiences more plant production and organic material accumulation.

Dissolved oxygen levels are also lower in Estuary B, especially in deeper water, due to the

decomposition of organic matter. (Adapted from Cole, 1994.)
10-3

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 10: Nutrients

oxygen (DO) in the water (see Chapter 9). As

stated earlier, an overabundance of such

nutrients can lead to uncontrolled growth of

phytoplankton (minute floating plants) or

algae—these are often referred to as blooms. 

Water clouded by thick patches of these tiny

plants does not allow sunlight to penetrate to

the bottom. Submerged aquatic vegetation

(see Chapter 18) requires light for

photosynthesis; if the plants’ fronds (leaves)

are covered or if the water is too cloudy

during much of the growing season, these

plants will die.

When algae and phytoplankton die, they are

decomposed by oxygen-consuming bacteria.

Especially slow-moving waterbodies with

insufficient mixing may become hypoxic (low

in oxygen). Under the worst conditions, the

bottom waters of an estuary turn anoxic

(without oxygen). Excessive nutrient

concentrations have been linked to hypoxic

conditions in over 50 percent of U.S.

estuaries. Even coastal ocean areas, such as

the Gulf of Mexico, have been impacted,

endangering economically and ecologically

important fisheries (USGS, 1999). 

High nutrient concentrations have also been

linked to harmful or nuisance phytoplankton

blooms—such as “red tides” and “brown

tides”—some of which produce harmful

toxins (see Chapter 19). Nutrients are also

believed to be one cause for the growth of the

potentially toxic dinoflagellate Pfiesteria,

found in estuaries along Atlantic coasts

(USGS, 1999). These events may result in

fish and shellfish kills and be harmful to

human health.

Cars and Factories

Atmospheric

deposition

Inorganic fertilizer

runoff

Natural runoff

Manure runoff

from feedlots

Runoff from

streets,

lawns, and

construction lots

Runoff and erosion

(from cultivation,

mining, construction,

and poor land use)

Discharge of treated

and untreated sewage

from wastewater

treatment plants and

septic systems

Detergents

Figure 10-2. Typical nutrient sources to an estuary.
10-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 10: Nutrients Unit One: Chemical Measures

Levels of Nutrients

Nutrient concentrations are always in flux,

responding to changes in:

• precipitation and amount of runoff;

• fertilizer or manure application rates;

• estuary flushing rates;

• water temperature;

• biological activity in the estuary; and/or

• the status of other water quality

parameters.

Figure 10-5 shows significant levels for

nutrients in estuarine waters.

Nutrient concentrations are usually greatest

during spring and early summer, when fertilizer

use and water flow from tributaries and

irrigation activities are high.

High nutrient concentrations can also be

detected during seasonal low-flow conditions

(USGS, 1999). During winter low-flow periods,

for example, the lack of land and aquatic plant

uptake combined with contributions from

groundwater can result in high nitrogen levels.

Nutrient levels downstream from urban areas

may also be high during low-flow periods. At

these times, contributions from point sources

can be greater relative to streamflow, and

dilution is less (USGS, 1999).

Nutrient levels also vary among watersheds.

Natural features (e.g., geology and soils) and

land management practices (e.g., drainage and

irrigation) can affect the movement of nitrogen

and phosphorus over land, creating local and

regional effects on estuarine water quality

(USGS, 1999). 

Tidal stage may also cause fluctuations in

nutrient levels, but many volunteer programs

have found that “chasing the tides” does not

yield enough additional information to make

the effort worthwhile. ■

Normal level of nitratenitrogen in unpolluted water

Total phosphorus stimulates

plant growth to surpass natural

eutrophication rates

Total phosphorus contributes

to increased plant growth

(eutrophication)

<1

0.1

0.03

Nutrient Concentration

(mg/l)

Nitrogen Phosphorus

Figure 10-5. Significant

levels of nutrients in

aquatic systems

(Campbell and

Wildberger, 1992).

Drainage

and Wastes

Organic

Nitrogen Inorganic

Nitrogen

Remineralizing

Microbes

Detritus Dissolved

Nitrogen

Denitrifying

Bacteria

Animals

Ocean

Exchange

Fishing Plankton

Nitrogen-fixing

Algae and Bacteria Air Deposition

Plants

Drainage

and Wastes

Organic

Phosphorus

Remineralizing

Microbes

Detritus Dissolved

Phosphorus

Animals

Ocean

Exchange

Plankton Fishing

Organic

Phosphorus

Inorganic

Phosphorus

Plants

Figure 10-3. The nitrogen cycle (adapted from USEPA, 1987).

Figure 10-4. The phosphorus cycle (adapted from USEPA, 1987).
10-5

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 10: Nutrients

Chapter 6 summarized several factors that

should be considered when identifying

monitoring sites, where to monitor in the water

column, and when to monitor. In addition to the

considerations in Chapter 6, a few additional

ones specific to nutrient monitoring are

presented here.

When to Sample 

In setting up a nutrient monitoring plan, the

program manager should ensure that the effort

will continue for several seasons. Since the

workings of an estuary are complex, a mere

year or two of nutrient data is insufficient to

capture the variability of the system. In fact, a

couple of years of unusual data may be quite

misleading and tell a story very different from

the long-term situation (note the variability in

Figure 10-6). 

Volunteers should sample nutrients on a

weekly basis, although biweekly sampling will

still yield valuable information. However,

sampling at a small number of sites every week

or two cannot possibly capture the constantly

changing water quality of an entire estuary. The

key to effective nutrient monitoring is to

sample at a sufficiently frequent interval and at

enough representative sites so that the data will

account for most of the inherent variability

within the system. In temperate climates, some

programs have eliminated wintertime

measurements when aquatic plants are dormant

and the effects of nutrients are not so marked.

A few measurements during the winter,

however, will provide a baseline of nutrient

levels that can be compared to the rest of the

year’s data. 

Where to Sample

If the monitoring program is designed to

pinpoint trouble spots in the estuary, the

program manager should cluster monitoring

sites where point and nonpoint sources of

nutrients appear to enter the water. Such sites

might include an area near the discharge pipe

of a wastewater treatment plant or adjacent to

an agricultural area where fertilizers are applied

or livestock congregate.

Because nutrient levels often vary with

depth, especially during the summer when the

estuary is well-stratified, volunteer groups may

wish to collect samples at different depths. Van

Dorn and Kemmerer samplers (see Chapter 7)

are commonly used to collect these kinds of

samples. In addition, there are several water

samplers designed primarily for collecting

samples at different depths. Appendix C

provides a list of equipment suppliers.

Special Consideration: 

The Different Forms of Nutrients

Nitrogen and phosphorus come in many

different chemical forms, or species, which are

determined by a number of environmental

conditions. Measuring each nutrient species can

help identify its source into the estuary.

Therefore, volunteer efforts to measure

different nutrient species can provide

significant information to resource managers.

2

1.6

1.2

0.8

0.4

0

Jan 97 Jul 97 Jan 98 Jul 98 Jan 99 Jul 99 Jan 00

Nitrite and Nitrate (mg/l)

Figure 10-6. Seasonal fluctuations of nitrite and nitrate—two forms of

nitrogen—in a typical mid-Atlantic estuary.

Sampling Considerations
10-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 10: Nutrients Unit One: Chemical Measures

Nitrogen Forms and Impacts 

Although nitrogen makes up about 80 percent

of the earth’s atmosphere, it is inaccessible to

most terrestrial and aquatic organisms. Some

types of bacteria and blue-green algae,

however, can “fix” nitrogen gas, converting it

to an inorganic nitrogen form—thereby making

it available to other organisms. 

In the estuary, nitrogen exists in a variety of

chemical (e.g., ammonium, nitrate, and nitrite)

and particulate and dissolved organic forms

(e.g., living and dead organisms). Table 10-1

summarizes information about different

nitrogen species and their connection to

surrounding land activities.

The quantity and form of nitrogen in the

water can also closely relate to dissolved

oxygen levels. Bacteria are able to convert

nitrogen into different nitrogen species and

gain energy from the process. Through

nitrification, some bacteria transform

ammonium into nitrite and then to nitrate. This

biological process consumes oxygen. When

nitrification is inhibited by low dissolved

oxygen conditions, ammonia or nitrite forms

of nitrogen may accumulate. 

Through denitrification, bacteria convert

nitrate to nitrite and then to nitrogen gas. This

process occurs under anoxic conditions and

helps rid the system of excess nitrogen. 

Nitrate and urea are highly soluble in water,

a characteristic which facilitates their transport

to the estuary by runoff. Ammonium is also

soluble in water; it can be transformed to

ammonia in low oxygen environments and

escape to the atmosphere. All of these nitrogen

species promote phytoplankton, algae, and

bacterial blooms (Phinney, 1999). Certain

nitrogen species can have other adverse

impacts. At high concentrations, nitrates are

toxic to eelgrass, and ammonia is toxic to fish

(Maine DEP, 1996).

Phosphorus Forms and Impacts

Phosphorus also exists in the water in

several forms: organic phosphate,

orthophosphate (inorganic, dissolved

phosphorus), total phosphorus (dissolved and

particulate), and polyphosphate (from

detergents). Orthophosphate in the water

comes from fertilizers and is the form

commonly measured. Organic phosphate

results from plant and animal waste.

Decomposition of dead plants and animals

also adds organic phosphorus to the water. In

general, excess phosphates can enter an

estuary from water treatment plants, sewage,

soils, agricultural fields, animal feedlot

operations, and lawns.

Many phosphorus species attach to soil

particles and are, therefore, transported to the

estuary with eroded soil. Especially high

phosphorus loads are often delivered during

periods of high runoff from storms or

irrigation activities.

Under oxygenated conditions, phosphate will

Nitrate (NO3

–),

Nitrite (NO2

–) and

NOx (“nox”)

Ammonium (NH4

+)

and unionized

ammonia (NH3)

Urea (an organic

form of nitrogen)

Nitrogen Species Notes About Possible Species Sources

• Make up 70 percent of total nitrogen inputs

from groundwater to smaller watersheds in

the Chesapeake Bay

• Make up approximately 15 percent of total

nitrogen found in agricultural fertilizers

• NO2

– is generally a short-lived nitrogen

species that is measured in low oxygen

environments 

• NOx from fossil fuel burning makes up at

least 25 percent of atmospheric nitrogen

inputs into coastal waters (Paerl and

Whiteall, 1999)

• Make up 5.8 percent of total nitrogen in

lawn fertilizer 

• Make up 20 percent of total nitrogen in

agricultural fertilizers

• Primary nitrogen component from animal

feedlot operations (AFOs)

• Makes up 12 percent of total nitrogen in

lawn fertilizer 

• Makes up 38-45 percent of total nitrogen in

agricultural fertilizers

Table 10-1. Examples of nitrogen species and notes about potential sources

(adapted from Phinney, 1999).
10-7

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 10: Nutrients

form chemical complexes with minerals such as

iron, aluminum, and manganese and fall to the

bottom sediments. In cases when this nutrient is

found mostly in sediments, water column

concentrations may not provide a full picture of

nutrient loads and impacts. If the bottom water

in an estuary has no oxygen, however,

phosphate bound to the sediments is released

back into the water. This release can fuel yet

another round of phytoplankton blooms.

Choosing a Sampling Method 

A dilemma arises for program managers

when deciding upon the appropriate method

for measuring nutrient levels in an estuary. On

one hand, kits for nitrogen and phosphorus

can be imprecise; on the other, submitting

prepared samples for lab analysis is costly and

time consuming. Program managers

frequently arrange to have a college or

professional lab donate its time and facilities

to the volunteer effort. 

If the data are intended to supplement state or

federal efforts, it is wise to confer with the

agency beforehand to determine an acceptable

monitoring method. Whatever sampling method

is chosen, program managers should

periodically compare the citizen monitoring

data to duplicate samples analyzed by another

method under laboratory conditions. 

The following sections provide an overview

of possible nutrient analysis methods, along

with each method’s advantages and pitfalls. 

Test Kits 

Several companies manufacture kits for

analyzing the various forms of nitrogen and

phosphorus. While the kits are not precise or

accurate when nutrient levels are low, the

manager may choose to use them when deemed

appropriate given the program’s data objectives.

The kits rely on a color comparison in which

the volunteer matches the color of a prepared

water sample to one in a set of provided

standards. The subjectivity of each volunteer’s

decision as well as ambient light levels will

influence the results to some degree. 

Kits are suitable for identifying major

nutrient sources, such as wastewater and

animal feedlots, where levels are generally

higher than the surface water in the estuary.

Areas where concentrations routinely exceed

concentrations of 1 mg/l are good candidates

for kit analysis. 

While the kits are generally easy to use,

many state and federal agencies will reject

nutrient data derived from their use because

of their imprecision and subjective nature. In

some cases, data that are collected from the

use of kits may be helpful as a screening tool.

Spectrophotometer 

A spectrophotometer measures the quantity

of a chemical based on its characteristic

absorption spectrum. This is accomplished 

by comparing the collected sample to a

reference sample, also called a standard.

Spectrophotometers are generally quite

accurate although the instruments are

expensive to purchase and maintain. Programs

with ample funds for equipment may want to

consider purchasing this reliable instrument,

which costs from $1,000 to $6,000. Because

reagents and standards are required, the

volunteer program will have an added

expense of a few hundred dollars.

The instrument requires proper maintenance

and precise calibration; therefore, the program

manager or someone familiar with this

equipment must oversee its care and use. 

Colorimeter 

A colorimeter compares the intensity of

color between the sample and a standard in

order to measure the quantity of a compound

in the sample solution. 

Cheaper than a spectrophotometer, electric

colorimeters offer citizen programs a

reasonably priced alternative. They are quite

accurate, fairly easy to use, and can provide

direct meter readout. Colorimeters range in

price from $250 to $2,000. 

Like the spectrophotometer, this instrument

can be used for forms of both nitrogen and
10-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 10: Nutrients Unit One: Chemical Measures

phosphorus. The colorimeter is a more

affordable alternative for those programs that

prefer a method less costly than the

spectrophotometer and more accurate than the

kits. 

Similar to a spectrophotometer, a

colorimeter requires standard maintenance

and reagents, which must be purchased on a

regular basis. The colorimeter provides

accurate data only when properly maintained

and precisely calibrated by a professional. 

Laboratory Analysis 

Analysis of nutrients by a professional

laboratory is by far the most accurate means

of obtaining nutrient data. Most laboratories

institute strict quality assurance and quality

control methods to ensure consistently reliable

results. A college or professional lab may

offer its services free of charge to the

volunteer program. 

If the program decides to use lab analysis,

it must ensure that its volunteers adhere to

strict guidelines while collecting samples.

Sloppy field collection techniques will result

in poor data no matter how sophisticated the

lab may be. ■

Reminder!

To ensure consistently high quality data,

appropriate quality control measures are

necessary. See “Quality Control and

Assessment” in Chapter 5 for details.

How to Monitor Nutrients 

General procedures for collecting and

analyzing samples for nutrients are presented in

this section for guidance only; they do not

apply to all sampling methods. Monitors

should consult with the instructions that

come with their sampling and analyzing

instruments. Those who are interested in

submitting data to water quality agencies

should also consult with the agencies to

determine acceptable equipment, methods,

quality control measures, and data quality

objectives (see Chapter 5).

Before proceeding to the monitoring site and

collecting samples, volunteers should review the

topics addressed in Chapter 7. It is critical to

confirm the monitoring site, date, and time; have

the necessary monitoring equipment and personal gear; and understand all safety considerations.

Once at the monitoring site, volunteers should

record general site observations, as discussed in

Chapter 7. A visual assessment of phytoplankton

density is particularly recommended to aid nutrient data interpretation—nutrient concentrations

in a water sample may be low because phytoplankton are utilizing the nutrients.

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site when sampling for nutrients: 

Procedure A—Equipment for test kit analysis

• fully stocked nitrogen and phosphorus

kits, with instructions for use;

• clean polypropylene sample bottles or

scintillation vials (60 ml) (see Chapter 7

for details on cleaning reusable sampling

containers);

• water sampler (if collecting samples from

other than the surface); and

• appropriate type of equipment and water

for making sample dilutions.
10-9

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 10: Nutrients

Procedure B—Equipment for preparing sample

for laboratory analysis

• clean polypropylene sample bottles or

scintillation vials (60 mg/l) (see Chapter 7

for details on cleaning reusable sampling

containers);

• filter assembly and supporting equipment

(many laboratories require filtered

samples);

• water sampler (if collecting samples from

other than the surface);

• ice cooler with ice packs to keep samples

cool and in darkness; and

• properly labeled preservation chemicals.

Sampling Hint:

If using a boat to reach the sampling location,

make sure that it is securely anchored. It is

best not to bring up the anchor until the

sampling is completed since mud (with

associated nutrients) may become stirred into

the water. 

STEP 2: Collect the water sample.

Volunteers must follow strict guidelines to

prevent contamination of the sample. For

example, it is preferable to use a standard

sampling bottle rather than a simple bucket

since a washed and capped bottle is less likely

to become contaminated than an open

container. 

Chapter 7 reviews general information about

collecting a water sample using a bottle or

Whirl-pak bag. Volunteers using bottles should

be sure to:

• Rinse the bottle by pushing it into the

water in a forward motion, holding the

container by the bottom. This technique

will keep water contaminated by skin oils

and dirt from entering the mouth. Fill the

bottle a quarter full and swish the water

around the inside, making sure to cover

all inside surfaces. Pour out the water on

the down-current side of the boat and

away from the actual sampling site. Rinse

the cap as well. 

• After rinsing, push the bottle back into

the water in the same manner to collect a

sample for analysis. 

• Fill the bottle to the shoulder, leaving an

airspace. Cap the bottle. 

• If the samples are not to be measured that

day, they should be preserved according

to the requirements specified by the test

kit manufacturer, laboratory conducting

the analysis, water quality agency, etc.

The preservation technique may vary

according to the type of nutrient and the

method by which it is measured.

• Store the container in a cold, dark ice

chest to minimize bacterial activity and

phytoplankton growth. 

• Filtered samples may require a

polypropylene syringe and filter that can

be screwed on. Bottle rinsing should be

done with filtered water before the final

sample is added.

NOTE: Volunteers using test kits may prefer to

place the kit’s test tube or bottle directly into the

water to collect the sample. Eyedroppers are

helpful in filling the test tube to the marked line.

STEP 3: Measure nutrients or prepare

sample for laboratory analysis.

Procedure A—Elements of test kit analysis 

• Conduct the test as soon as possible after

collecting the water sample. As the

sample sits, organisms living in the water

will use up nutrients, changing the

nutrient concentrations in the water.

• Before starting the analysis, double-check

that the bottles, test tube or sample bottle,

and any other equipment that will come

in contact with the sample are clean.

Reagents should be maintained at about

20°C to yield the best results. 

• Make sure the sample water is well

mixed. 
10-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 10: Nutrients Unit One: Chemical Measures

• Follow the protocol for each nutrient type

as outlined in the instructions

accompanying the kit. 

• Immediately record the results on the data

sheet. 

Procedure B—Prepare sample for laboratory

analysis 

Volunteers may need to filter the sample,

depending on the nutrient species being

analyzed. This activity removes the particulate

nutrient fraction from the dissolved fraction.

Individual laboratories may require different

filtering techniques; therefore, volunteer groups

should consult with their laboratory to

determine how samples should be filtered.

STEP 4: Clean up and send off data.

Volunteers should thoroughly clean all

equipment, whether using the test kit or the lab

preparation method. Follow laboratory or test

kit instructions for cleaning. Allow the

equipment to air dry before storing it. If

volunteers used the filtration technique, they

should detach the filter unit from the syringe,

unscrew it, and clean all parts. The paper filter

can be thrown away. 

Properly dispose of wastes generated during

the performance of tests (see Chapter 7).

Make sure that the data sheet is complete and

accurate. Volunteers should make a copy of the

completed data sheet before sending it to the

project manager in case the original data sheet

becomes lost.

After preserving the samples, follow

laboratory guidelines for packing and shipping

them to the analytical lab. This step should be

done as soon as possible. 

Warning!

The interpretation of nutrient concentration data must be done with care. While high nutrient levels

suggest the potential for explosive algal growth, low levels do not necessarily mean the estuary is

receiving less nutrient input. Large quantities of nutrients may flow into the estuary and be quickly

taken up by phytoplankton. Zooplankton, in turn, graze upon the phytoplankton. Phosphorus may

also bind with minerals in the sediment, which settle to the bottom, but may be reintroduced to

the water column under low oxygen conditions. 

In this scenario, although water nutrient concentration is low, the quantity of nutrients tied up in

sediment and biomass (living matter) is high. Chlorophyll analysis is needed to quantify the

phytoplankton biomass and interpret the low nutrient concentrations. 
10-11

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 10: Nutrients

Over the past 30 years, scientists have

collected a large amount of convincing

information demonstrating that air pollutants

can be deposited on land and water, sometimes

at great distances from their original sources.

Atmospheric deposition, then, can be an

important contributor to declining estuarine

water quality. 

What Is Atmospheric Deposition and How

Does It Occur?

Nitrogen pollutants released into the air are

carried by wind away from their place of origin.

These pollutants come from manmade sources

such as fossil fuel burning, industrial processes,

cars and other forms of transportation, fertilizer,

and the volatilization of animal wastes. Air

deposition can also come from natural sources

of emissions. 

Atmospheric deposition occurs when

pollutants in the air fall on the land or water.

Pollution deposited in snow, fog, or rain is

called wet deposition, while the deposition of

pollutants as dry particles or gases is called dry

deposition. Air pollution can be deposited into

waterbodies either directly from the air onto the

surface of the water or through indirect

deposition, where the pollutants settle on the

land and are then carried into a waterbody by

runoff. 

How Much Water Pollution from Nutrients

Is Atmospheric?

Nitrogen is one of the most common air

deposition pollutants, especially in the eastern

United States. Since 1940, human activity has

doubled the rate of nitrogen cycling through the

global atmosphere, and the rate is accelerating

(Vitousek et al., 1997). Depending on the

waterbody and watershed being considered, it is

estimated that roughly a quarter of the nitrogen

in an estuary comes from air sources (Paerl and

Whiteall, 1999). Table 10-2 shows estimated

nitrogen sources in the Chesapeake Bay

watershed. 

In the Chesapeake Bay region, it is estimated

that 37 percent of the nitrogen entering the bay

from air sources comes from electric utilities;

35 percent from cars and trucks; 6 percent 

from industry and other large sources of fossil

fuel-fired boilers; and 21 percent from other

sources such as ships, airplanes, lawnmowers,

construction equipment, and trains (Alliance for

the Chesapeake Bay, 1997).

Some other estuaries have also attempted to

estimate how much of the nitrogen in their

water comes from air sources, including both

direct and indirect deposition (see Table 10-3).

Special Topic: Atmospheric Deposition of Nutrients

Table 10-2. Estimated sources of nitrogen in the

Chesapeake Bay (Alliance for the Chesapeake Bay, 1997).

*This estimate of air sources includes indirect air

deposition that reaches the bay as runoff from forests,

streets, farmland, and anywhere else it is deposited. 

Waterborne point sources (e.g.,

industry, sewage treatment plants,

etc.)

Runoff from land* (e.g., farms,

lawns, city streets, golf courses,

etc.)

Air sources* (e.g., electric power

plants, vehicles, municipal waste

combustors, etc.)

25%

50%

25%
10-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 10: Nutrients Unit One: Chemical Measures

What Can Volunteers Do?

Presently, atmospheric deposition monitoring

by volunteers is in its early stages. One

potential procedure that may interest volunteer

groups is a passive sampler that measures

ammonia concentrations (Greening, 1999). The

samplers are small disks that are set out for

several days (up to one week), collected, and

then sent to a laboratory for analysis. 

The procedure is still being developed 

and refined.

Another way volunteers can assist with

atmospheric deposition monitoring is to

measure rainfall. Rainfall measurements in

watershed sub-basins are critical in determining

the contribution of wet deposition to estuarine

nutrient concentrations. Precipitation

monitoring can also be instrumental in

determining potential causes for other pollutants

(e.g., sediments).

Steps for Monitoring Precipitation

• Place a rain gauge in an open area away

from interference from overhead

obstructions and more than one meter

above the ground (see Chapter 7). Avoid

obstructions making angles greater than

45o from the top of the gauge. 

• Check the gauge after each rainfall,

record the amount of precipitation and the

time of measurement, and then empty the

gauge. If the gauge sits after a rainfall,

evaporation can falsify the measurement. 

• Make sure that the data sheet is complete

and accurate. Volunteers should make a

copy of the completed data sheet before

sending it to the project manager in case

the original data sheet becomes lost. ■

Bay or Estuary Million Tons of Nitrogen % of Total Nitrogen

Albemarle-Pamlico Sounds 9 38-44

Delaware Bay 8 15

Delaware Inland Bays* - 21

Long Island Sound 12 20

Massachusetts Bays* - 5-27

Narragansett Bay* 0.6 12

Sarasota Bay* - 2

Tampa Bay* 1.1 28

Table 10-3. Amount and percentage of nitrogen entering the estuarine systems due to atmospheric deposition

(NEP Web site). 

* Indicates measurement of direct deposition to water surface only. 
10-13

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 10: Nutrients

Portions of this chapter were excerpted and adapted from:

U.S. Environmental Protection Agency. Web site: http://www.epa.gov/owow/oceans/airdep/index.html

Other references:

Alliance for the Chesapeake Bay. 1997. Air Pollution and the Chesapeake Bay. White Paper of the

Alliance for the Chesapeake Bay. 16 pp.

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L.S. Clesceri, A.E. Greenberg, A.D. Eaton (eds). Washington, DC.

Campbell, G., and S. Wildberger. 1992. The Monitor’s Handbook. LaMotte Company, Chestertown,

MD. 71 pp.

Cole, G. A. 1994. Textbook of Limnology. 4th ed. Waveland Press, Prospect Heights, IL.

Dates, G. 1994. “Monitoring for Phosphorus or How Come They Don’t Tell You This Stuff in 

the Manual?” The Volunteer Monitor 6(1).

Ellett, K. 1993. Chesapeake Bay Citizen Monitoring Program Manual. Alliance for the

Chesapeake Bay. Richmond, VA. 57 pp.

Greening, H. 1999. “Atmospheric Deposition Monitoring.” In: Meeting Notes—U.S. Environmental

Protection Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer

Estuary Monitoring: Wave of the Future. Mobile, AL: March 17-19, 1999.

Katznelson, R. 1997. “Nutrient Test Kits: What Can We Expect?” The Volunteer Monitor 9(1).

Kerr, M., L. Green, M. Raposa, C. Deacutis, V. Lee, and A. Gold. 1992. Rhode Island Volunteer

Monitoring Water Quality Protocol Manual. URI Coastal Resources Center, RI Sea Grant, and

URI Cooperative Extension. 38 pp.

LaMotte Chemical Products Company. Undated. Laboratory Manual for Marine Science Studies.

Educational Products Division, Chestertown, MD. 41 pp.

Maine Department of Environmental Protection (DEP). May 1996. A Citizen’s Guide to Coastal

Watershed Surveys. 78 pp.

Paerl, H. W., and D. R. Whiteall. 1999. “Anthropogenically-Derived Atmospheric Nitrogen

Deposition, Marine Eutrophication and Harmful Algal Bloom Expansion: Is There a Link?”

Ambio 28(4): 307-311.

Phinney, J. 1999. “Nurients and Toxics.” In: Meeting Notes—U.S. Environmental Protection

Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary

Monitoring: Wave of the Future. Astoria, OR: May 19-21, 1999.

Stancioff, E. November 1996. Clean Water: A Guide to Water Quality Monitoring for Volunteer

Monitors of Coastal Waters. Maine/New Hampshire Sea Grant Marine Advisory Program and

Univ. of Maine Cooperative Extension. Orono, ME. 73 pp.

References and Further Reading
10-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 10: Nutrients Unit One: Chemical Measures

U.S. Geological Survey (USGS). 1999. The Quality of Our Nation’s Waters-Nutrients and

Pesticides. USGS Circular 1225. 82 pp.

Vitousek, P.M., J. Aber, R.W. Howarth, G.E. Likens, P.A. Matson, D.W. Schindler, W.H. Schlesinger,

and G.D. Tillman. 1997. “Human Alteration of the Global Nitrogen Cycle: Causes and

Consequences.” Issues in Ecology. No. 1, Spring 1997. Ecological Society of America, 15 pp. 

Web sites:

Air Deposition

National Estuary Program (NEP): http://www.epa.gov/owow/estuaries/airdep.htm
Chapter11 pH and Alkalinity

Every estuary is part of the carbon cycle. Carbon moves from the atmosphere into

plant and animal tissue, and into water bodies. Alkalinity, acidity, carbon dioxide

(CO2), pH, total inorganic carbon, and hardness are all related and are part of the

inorganic carbon complex. There are fascinating interrelationships among these

factors. For example, the amount of carbon dioxide in the water affects (and is

affected by) the pH and photosynthesis.
Photos (l to r): G. Carver, K. Register, R. Ohrel
11-1

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 11: pH and Alkalinity

This chapter discusses two additional chemical parameters of estuaries that are

monitored to increase our understanding of the water’s health: pH and alkalinity.

Since the pH of water is critical to the survival of most aquatic plants and animals,

monitoring pH values is an important part of nearly every water quality

monitoring program. The testing is quick and easy and can establish a valuable

baseline of information so that unanticipated water quality changes can be better

understood. 

Testing water samples for total alkalinity measures the capacity of the water to

neutralize acids. This test is important in determining the estuary’s ability to

neutralize acidic pollution from rainfall or wastewater. 

Every estuary is part of the carbon cycle. Carbon moves from the atmosphere

into plant and animal tissue, and into water bodies. Alkalinity, acidity, carbon

dioxide (CO2), pH, total inorganic carbon, and hardness are all related and are part

of the inorganic carbon complex. There are fascinating interrelationships among

these factors. For example, the amount of carbon dioxide in the water affects (and

is affected by) the pH and photosynthesis.

Overview
11-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 11: pH and Alkalinity Unit One: Chemical Measures

Routine monitoring of a waterbody should

provide baseline information about normal pH

and alkalinity values. Unanticipated decreases

in pH could be indications of acid rain, runoff

from acidic soils, or contamination by

agricultural chemicals. Values of pH outside

the expected range of 5.0 to 10.0 should be

considered as indications of industrial

pollution or some cataclysmic event.

Likewise, a long-term database on alkalinity

values provides researchers with the ability to

detect trends in the chemical makeup of

estuary waters. ■

Why Monitor pH and Alkalinity?

pH

pH is a measure of how acidic or basic (alkaline) a solution is. It measures the hydrogen ion

(H+) activity in a solution, and is expressed as a

negative logarithm. The pH measurements are

given on a scale of 0.0 to 14.0 (Figure 11-1).

Pure water has a pH of 7.0 and is neutral;

water measuring under 7.0 is acidic; and that

above 7.0 is alkaline or basic. Most estuarine

organisms prefer conditions with pH values

ranging from about 6.5 to 8.5. 

Values of pH are based on the logarithmic

scale, meaning that for each 1.0 change of pH,

acidity or alkalinity changes by a factor of ten;

that is, a pH of 5.0 is ten times more acidic than

6.0 and 100 times more acidic than 7.0. When

the hydrogen and hydroxyl ions are present in

equal number (the neutral point), the pH of the

solution is 7. 

The Role of pH in the Estuarine Ecosystem

Water’s pH is affected by the minerals dissolved in the water, aerosols and dust from the

air, and human-made wastes as well as by

plants and animals through photosynthesis and

respiration. Human activities that cause significant, short-term fluctuations in pH or long-term

acidification of a waterbody are exceedingly

harmful. For instance, algal blooms that are

often initiated by an overload of nutrients can

cause pH to fluctuate dramatically over a fewhour period, greatly stressing local organisms.

Acid precipitation in the upper freshwater

reaches of an estuary can diminish the survival

rate of eggs deposited there by spawning fish.

Several other factors also determine the pH

of the water, including: 

• bacterial activity; 

• water turbulence; 

• chemical constituents in runoff flowing

into the waterbody; 

• sewage overflows; and

• impacts from other human activities both

in and outside the drainage basin (e.g.,

acid drainage from coal mines, accidental

spills, and acid precipitation). 

Estuarine pH levels generally average from

7.0 to 7.5 in the fresher sections, to between 8.0

and 8.6 in the more saline areas. The slightly

alkaline pH of seawater is due to the natural

buffering from carbonate and bicarbonate dissolved in the water.

The pH of water is critical to the survival of

most aquatic plants and animals. Many species

have trouble surviving if pH levels drop under

5.0 or rise above 9.0. Changes in pH can alter

other aspects of the water’s chemistry, usually

to the detriment of native species. Even small

shifts in the water’s pH can affect the solubility

of some metals such as iron and copper. Such

changes can influence aquatic life indirectly; if

the pH levels are lowered, toxic metals in the

estuary’s sediment can be resuspended in the

water column. This can have impacts on many

aquatic species. See Chapter 12 for more information on toxins. ■
11-3

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 11: pH and Alkalinity

Chapter 6 summarized several factors that

should be considered when determining monitoring sites, where to monitor, and when to

monitor. In addition to the considerations in

Chapter 6, a few additional ones specific to

monitoring pH are presented here.

When to Sample

It is well-established that levels of pH fluctuate throughout the day and season, and a single

pH measure during the day may not draw a

very accurate picture of long-term pH conditions in the estuary. Photosynthesis by aquatic

plants removes carbon dioxide from the water;

this significantly increases pH. A pH reading

taken at dawn in an area with many aquatic

plants will be different from a reading taken six

hours later when the plants are photosynthesizing. Likewise, in waters with plant life (including planktonic algae), an increase in pH can be

expected during the growing season. For these

reasons, it is important to monitor pH values at

the same time of day if you wish to compare

your data with previous readings. It is also

important to monitor pH values over a long

period of time to provide useful data. The 

actual time to measure pH will depend on local

conditions and the monitoring goals of the 

volunteer program.

Choosing a Sampling Method

The pH test is one of the most common

analyses done in volunteer estuary monitoring

programs. In general, citizen programs use one

of two methods to measure pH: (1) the colorimetric method or (2) electronic meters. Both

require that measurements be taken in the field,

since the pH of a water sample can change

quickly due to biological and chemical processes. 

Color comparator (also called “colorimetric”)

field kits are easy to use, inexpensive, and sufficiently accurate to satisfy the needs of most

programs. The colorimetric method can also be

used with an electronic colorimeter. If very precise measures are

required, more

expensive electronic pH meters

provide extremely accurate readings. Test paper

strips to obtain

pH are unsuitable for use in

estuarine waters

since they do not

provide consistent measurements in salt

water. The following sections

describe the use

of the two common methods.

Colorimetric

Method

Colorimetric

means “to measure color.” In a

colorimetric test

method, reagents

are added to a

water sample,

and a reaction occurs which produces a color.

The color can be measured visually or electronically. This method is not suitable for water

containing colored materials such as dissolved

organic compounds or excessive algae. For

water samples that are colored, a meter is suggested.

Visual Method to Measure Color

Field kits cover a range of pH values. They

cost between $15 and $50, depending on the

range of pH values to be tested. These kits

come with several color standards built into a

plastic housing unit or printed on a card. After

adding reagents according to the instructions,

the volunteer compares the color in the test tube

Sampling Considerations

Lye, sodium hydroxide (NaOH)

Bleach

Ammonia

Milk of Magnesia,

soap solutions

Baking soda

Sea water

Blood

Distilled water

Water

Rain water, urine

Boric acid, black coffee

Tomatoes, grapes

Vinegar, wine, soft drinks, beer,

orange juice, some acid rain

Lemon juice

Battery acid

Oven cleaners

Stomach acid

Saliva

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Alkaline Neutral Acidic

Figure 11-1. pH range

scale.
11-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 11: pH and Alkalinity Unit One: Chemical Measures

with the standards to determine the pH value. If

the general pH values of the estuary are known,

pick a kit that includes these values within its

range of sensitivity. Some programs prefer to

use a wide-range kit that covers pH values from

3.0 to 10.0 until the measured range of values

for that waterbody has been established. After

determining the actual range over several seasons, switch to a narrower range kit for greater

accuracy. Make sure kits have been checked

against pH standards. 

Electronic Method to Measure Color

An electronic colorimeter measures the

amount of light that travels through the reacted

sample and converts the measurement to an

analog or digital reading (LaMotte, 1999). A

reagent is added to the water sample in a test

tube, which is then inserted into the colorimeter

for analysis. Usually electronic colorimeters are

capable of testing multiple water quality parameters. 

pH Meters 

Although more expensive than the colorimetric field kits, pH meters give extremely accurate

readings of a wide range of pH values. The

more economical pH testers cost about $40.

Some more expensive meters ($75 - $750) also

will display the water temperature, and some

meters have cables so that you can obtain readings throughout the water column. Unlike the

colorimetric method, meters can be used even if

the water is clouded or colored. ■

Helpful Hint:

If your water quality monitoring program

plans to collect data on alkalinity, pH meters

with built-in temperature sensors are

required rather than the colorimetric kits.

pH Calibration Standards

Whether you use a field kit, pH meter, or colorimeter unit, calibration standards (also called

“buffer solutions”) are employed to ensure that your equipment is accurate. The standards most

commonly used are pH 4.00 (or 4.01), pH 7.00, and pH 10.00. They are available in liquid or

powder form (the powder is added to demineralized or deionized water). These pH standards

cost from $5 to $25 each, depending on the quantity of calibrations you will be conducting. 

Following is information regarding buffers: 

• Because buffer pH values change with temperature, the buffer solutions should be at

room temperature when you calibrate the meter. Usually you can calibrate your pH

equipment at home, a few hours before using it. Check manufacturer’s instructions.

• Do not use a buffer after its expiration date. 

• Always cap the buffers during storage to prevent contamination. 

• Do not reuse buffer solutions!
11-5

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 11: pH and Alkalinity

How to Measure pH Values

General procedures for measuring pH are

presented in this section for guidance only;

they do not apply to all sampling methods.

Monitors should consult with the

instructions that come with their sampling

and analyzing instruments. Those who are

interested in submitting data to water

quality agencies should also consult with

the agencies to determine acceptable

equipment, methods, quality control

measures, and data quality objectives (see

Chapter 5).

Before proceeding to the monitoring site

and collecting samples, volunteers should

review the topics addressed in Chapter 7. It is

critical to confirm the monitoring site, date,

and time; have the necessary monitoring

equipment and personal gear; and understand

all safety considerations. Once at the

monitoring site, volunteers should record

general site observations, as discussed in

Chapter 7.

Reminder!

To ensure consistently high quality data,

appropriate quality control measures are

necessary. See “Quality Control and

Assessment” in Chapter 5 for details.

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site for each sampling session:

• pH colorimetric field kit; or 

• pH meter with built-in temperature 

sensor; or 

• colorimeter unit with reagents.

STEP 2: Collect the sample.

If you are using the

colorimetric method to measure

pH, you can fill the test tube by

lowering it into the water. If

using a meter, you can

sometimes put the meter directly

in the water—you don’t need to

collect a sample. But if

monitoring from a dock or boat,

you will need to collect a water

sample using screw-cap bottles,

Whirl-pak bags, or water

samplers. Refer to Chapter 7 for

details.

STEP 3: Measure pH values.

Colorimetric Method

The colorimetric methods (both visual and

electronic meter) use indicators that change

color according to the pH of the solution.

Follow the directions in your colorimetric kit. 

Since the test tube for the colorimetric tests

is small, a clean eyedropper is useful as you

fill the tube with the correct amount of sample

water. With colorimetric kits, you add a

chemical or two (reagents) to your water

sample, and compare the resulting color of the

water sample to the color standards of known

pH values. With the field kits, which use

visual assessments, it is helpful to place white

paper in the background of the tube to

emphasize any color differences, especially if

the sample’s color is faint. Record the pH value

of the standard that most closely matches the

color of the sample. If the sample hue is

between two standards, check your program’s

quality assurance project plan (QAPP)

(see Chapter 5). Some QAPPs require you 

to average the values of the two closest

standards, and record this number as the pH.

Other plans require you to select the closest

value, and do not allow you to average the

values.

Volunteer using a color comparator,

or colorimetric field kit (photo by 

K. Register).
11-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 11: pH and Alkalinity Unit One: Chemical Measures

Alkalinity (also known as “buffer capacity”)

is a measure of the capacity of water to

neutralize acids. Alkaline compounds such as

bicarbonates, carbonates, and hydroxides,

remove hydrogen ions and lower the acidity

of the water (thereby increasing pH). They

usually do this by combining with the

hydrogen ions to make new compounds. 

Alkalinity is influenced by rocks and soils,

salts, certain plant activities, and certain

industrial wastewater discharges. Some water

can test on the acid side of the pH scale and

still rank high in alkalinity! This means that,

while the water might be acidic, it still has a

capacity to buffer, or neutralize, acids.

Total alkalinity is measured by measuring

the amount of acid (e.g., sulfuric acid) needed

to bring the sample to a pH of 4.2. At this pH,

all the alkaline compounds in the sample are

“used up.” The result is reported as milligrams per liter of calcium carbonate (mg/l

CaCO3).

The Role of Alkalinity in the Estuarine

Ecosystem

Measuring alkalinity is important in

determining the estuary’s ability to neutralize

acidic pollution from rainfall or wastewater.

Without this acid-neutralizing capacity, any

acid added to a body of water would cause an

immediate change in pH. This buffering

capacity of water, or its ability to resist pH

change, is critical to aquatic life. The

estuary’s capacity to neutralize acids will vary

between the freshwater reaches of the estuary

and the portions with higher salinity. 

Total Alkalinity Levels in Estuaries

Total alkalinity of seawater averages 116

mg/l and is greater than fresh water, which

can have a total alkalinity of 30 to 90 mg/l,

depending on the watershed. The brackish

waters of an estuary will have total alkalinity

between these values. ■

TOTAL ALKALINITY

pH Meter

Consistent calibration of equipment will

ensure that high quality data are collected. The

pH meter should be calibrated prior to sample

analysis and after every 25 samples according

to the instructions in the meter manual. Use

two pH standard buffer solutions (see the box,

“pH Calibration Standards,” page 11-4). After

calibration, place the electrode into the water

sample and record the pH. The glass electrode

on these meters must be carefully rinsed with

deionized water after each use to ensure

accurate results in the future. 

STEP 4: Clean up and send off data.

Volunteers should thoroughly clean 

all equipment.

Make sure that the data sheet is complete,

legible, and accurate, and that it accounts for

all samples. Volunteers should make a copy of

the completed data sheet before sending it to

the designated person or agency in case the

original data sheet becomes lost. ■
11-7

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 11: pH and Alkalinity

General procedures for measuring alkalinity

are presented in this section for guidance

only; they do not apply to all sampling

methods. Monitors should consult with the

instructions that come with their sampling

and analyzing instruments. Those who are

interested in submitting data to water

quality agencies should also consult with

the agencies to determine acceptable

equipment, methods, quality control

measures, and data quality objectives (see

Chapter 5).

Before proceeding to the monitoring site

and collecting samples, volunteers should

review the topics addressed in Chapter 7. It is

critical to confirm the monitoring site, date,

and time; have the necessary monitoring

equipment and personal gear; and understand

all safety considerations. Once at the

monitoring site, volunteers should record

general site observations, as discussed in

Chapter 7.

The alkalinity method described below

(using a digital titrator) was developed by the

Acid Rain Monitoring Project of the University

of Massachusetts Water Resources Research

Center (River Watch Network, 1992).

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site for each sampling session:

• digital titrator;

• 100-ml graduated cylinder;

• 250-ml beaker;

• pH meter with built-in temperature 

sensor;

Sampling Considerations

How to Measure Alkalinity

Choosing a Sampling Method

For total alkalinity, a double endpoint

titration using a pH meter and a digital titrator

is recommended. This can be done in the field

or in the lab. If you plan to analyze alkalinity

in the field, it is recommended that you use a

digital titrator. Another method for analyzing

alkalinity uses a buret. For volunteer programs,

using a digital titrator is recommended over the

buret, because digital titrators are portable,

economical, take less time, and have easy-toread endpoints (results). 

Digital Titrator 

This method involves titration, the addition

of small, precise quantities of sulfuric acid

(the reagent) to the sample until the sample

reaches a certain pH (the endpoint). The

amount of acid used corresponds to the total

alkalinity of the sample. 

Digital titrators have counters that display

numbers. A plunger is forced into a cartridge

containing the reagent by turning a knob on

the titrator. As the knob turns, the counter

changes in proportion to the amount of

reagent used. Alkalinity is then calculated

based on the amount used. Digital titrators

cost approximately $100; the reagents

(chemicals) to conduct total alkalinity tests

cost about $36. Additionally, alkalinity

standards are needed for accuracy checks (see

the box, “Alkalinity Calibration Standards,”

page 11-9). ■

Reminder!

To ensure consistently high quality data,

appropriate quality control measures are

necessary. See “Quality Control and

Assessment” in Chapter 5 for details.
11-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 11: pH and Alkalinity Unit One: Chemical Measures

• reagent (sulfuric acid titration cartridge,

0.16 N);

• standard alkalinity ampules, 0.500 N,

for accuracy check; and

• bottle with deionized water to rinse pH

meter electrode.

STEP 2: Collect the sample.

If you plan to analyze a water sample in the

lab for alkalinity, then follow these collection

and storage steps:

• Use 100 ml plastic or glass bottles. 

• Label the bottle with site name, date,

time, data collector, and analysis to be

performed.

• Wearing gloves, plunge the bottle into the

water. Fill the bottle completely and cap

tightly.

• Avoid excessive agitation and prolonged

exposure to air.

• Place the bottle in the cooler. Samples

should be analyzed as soon as possible,

but can be stored at least 24 hours by

cooling to 4°C (39°F) or below. NOTE:

Samples should be warmed to room temperature before analyzing (Hach, 1997).

STEP 3: Measure total alkalinity.

Alkalinity is usually measured using sulfuric

acid with a digital titrator. Follow the steps

below in the field or lab. Remember to wear

latex or rubber gloves.

Add sulfuric acid to the water sample in measured amounts until the three main alkaline

compounds (bicarbonate, carbonate, and

hydroxide) are converted to carbonic acid. At

pH 10, hydroxide (if present) reacts to form

water. At pH 8.3, carbonate is converted to

bicarbonate. At pH 4.5, all carbonate and bicarbonate are converted to carbonic acid. Below

this pH, the water is unable to neutralize the sulfuric acid and there is a linear relationship

between the amount of sulfuric acid added to the

sample and the change in the pH of the sample.

So, more sulfuric acid is added to the sample to

reduce the pH by exactly 0.3 pH units (which

corresponds to an exact doubling of the pH) to a

pH of 4.2. However, the exact pH at which the

conversion of these bases might have happened,

or total alkalinity, is still unknown. 

Arriving at total alkalinity requires an equation (given below) to extrapolate back to the

amount of sulfuric acid that was added to actually convert all the bases to carbonic acid. A

multiplier (0.1) then converts this to total alkalinity as mg/l of calcium carbonate (CaCO3). To

determine the alkalinity of your sample, follow

these steps:

• Samples should be warmed to room temperature before analyzing.

• Insert a clean delivery tube into the 0.16N

sulfuric acid titration cartridge and attach

the cartridge to the titrator body. 

• Hold the titrator, with the cartridge tip

pointing up, over a sink or waste bottle.

Turn the delivery knob to eject air and a

few drops of titrant. Reset the counter to

0 and wipe the tip. 

• Measure the pH of the sample using a pH

meter. If it is less than 4.5, skip to step 3a,

page 11-9. 

• Insert the delivery tube into the beaker

containing the sample. Turn the delivery

knob while magnetically stirring the

beaker until the pH meter reads 4.5.

Record the number of digits used to

achieve this pH. Do not reset the counter. 

• Continue titrating to a pH of 4.2 and

record the number of digits. 

• Apply the following equation: 

Alkalinity (as mg/l CaCO3) = (2a - b) x 0.1

Where: 

a = digits of titrant to reach pH 4.5

b = digits of titrant to reach pH 4.2 

(including digits required to get 

to pH 4.5)

0.1 = digit multiplier for a 0.16 titration 

cartridge and a 100 ml sample
11-9

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 11: pH and Alkalinity

Example: 

Initial pH of sample is 6.5. 

It takes 108 turns to get to a pH of 4.5. 

It takes another 5 turns to get to pH 4.2, 

for a total of 113 turns. 

Alkalinity = [(2 x 108) - 113] x 0.1 

= 10.3 mg/l

• Record alkalinity as mg/l CaCO3 on the

data sheet. 

• Rinse the beaker with distilled water

before the next sample. 

STEP 3a:

If the pH of your water sample, prior 

to titration, is less than 4.5, proceed as follows: 

• Insert the delivery tube into the

beaker containing the sample. 

• Turn the delivery knob while swirling

the beaker until the pH meter reads

exactly 0.3 pH units less than the initial

pH of the sample. 

• Record the number of digits used to

achieve this pH. 

• Apply the equation as before, but a = 0

and b = the number of digits required to

reduce the initial pH exactly 0.3 pH units. 

Example: 

Initial pH of sample is 4.3. 

Titrate to a pH of 0.3 units less than the

initial pH; in this case, 4.0.

It takes 10 digits to get to 4.0. 

Enter this in the 4.2 column on the data

sheet and note that the pH endpoint is 4.0. 

Alkalinity = (0 - 10) x 0.1 

Alkalinity = -1.0

• Record alkalinity as mg/l CaCO3 on the

data sheet.

• Rinse the beaker with distilled water

before the next sample.

STEP 4: Perform an accuracy check.

This accuracy check should be performed

on the first field sample titrated, again about

halfway through the field samples, and at the

final field sample. Check the pH meter

against pH 7.00 and 4.00 buffers after every

10 samples. 

• Snap the neck off an alkalinity ampule

standard, 0.500 N; or, if using a standard

solution from a bottle, pour a few milliliters of the standard into a clean beaker. 

• Pipet 0.1 ml of the standard to the titrated

sample (see above). Resume titration

back to the pH 4.2 endpoint. Record the

number of digits needed. 

• Repeat using two more additions of 0.1

ml of standard. Titrate to the pH 4.2 after

each addition. Each 0.1 ml addition of

standard should require 250 additional

digits of 0.16 N titrant. 

Note on Data Sheet for Alkalinity

Data sheets should be specialized depending on which methods

your program uses to measure each parameter—and this is true

for alkalinity, too. With the method described in this manual, your

worksheet should include places for volunteers to record the

results of the various steps described.

Alkalinity Calibration Standards 

You will need to do an accuracy check on your alkalinity test

equipment before the first field sample is titrated, again about

halfway through the field samples, and at the final field sample. For

this, you will need an alkalinity standard. Often, these come in premeasured glass ampules. To use, break off the tip of the glass

ampule and pour the liquid into a beaker. Then, follow the directions

found under “Step 4: Perform an accuracy check.” The price for the

alkalinity standards is about $23 for 20 2-ml ampules.
11-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 11: pH and Alkalinity Unit One: Chemical Measures

Portions of this chapter were excerpted and adapted from:

Ellett, K. 1993. Chesapeake Bay Citizen Monitoring Program Manual. Alliance for the

Chesapeake Bay. Richmond, VA. 57 pp.

Green, L. 1998. “Let Us Go Down to the Sea—How Monitoring Changes from River to

Estuary.” The Volunteer Monitor 10(2): 1-3.

Hach. 1997. Hach Water Analysis Handbook. 3rd ed. Hach Company. Loveland, CO.

LaMotte Chemical Products Company. Undated. Laboratory Manual for Marine Science Studies.

LaMotte Educational Products Division, Chestertown, MD. 41 pp.

River Watch Network. 1992. Total Alkalinity and pH Field and Laboratory Procedures. (Based

on University of Massachusetts Acid Rain Monitoring Project.)

Other references:

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L. S. Clesceri, A. E. Greenberg, A. D. Eaton (eds). Washington, DC.

Godfrey, P. J. 1988. Acid Rain in Massachusetts. University of Massachusetts Water Resources

Research Center. Amherst, MA.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A

Methods Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

References and Further Reading

STEP 5: Return the field data sheets

and/or samples to the lab. 

Volunteers should thoroughly clean all

equipment and transport the samples to the

designated lab. Alkalinity samples must be

analyzed within 24 hours of their collection. If

the samples cannot be analyzed in the field,

keep the samples on ice and take them to the

lab or drop-off point as soon as possible.

Make sure that the data sheets are complete,

legible, and accurate, and that they account for

all samples. Volunteers should make a copy of

the completed data sheets before sending

them to the designated person or agency in

case the original data sheet becomes lost. ■
Chapter 12Toxins

Testing for toxins requires specialized equipment and expertise beyond the means

of most volunteer monitoring programs. Nonetheless, it is important to understand

the sources of toxins and the role they play in estuaries. Volunteers can provide

valuable assistance with research projects by providing local knowledge of a

watershed and potential sources of toxic compounds and by collecting fish and

invertebrates for laboratory analysis.
Photos (l to r): G. Carver, R. Ohrel, R. Ohrel
12-1

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 12: Toxins

Since industrialization in the late 1940s and 1950s, the amount of contaminants and

toxic substances put into estuaries has greatly increased. These contaminants include

heavy metals (such as mercury, lead, cadmium, zinc, chromium, and copper) and synthetic (manmade) organic compounds such as polycyclic aromatic hydrocarbons

(PAHs), polychlorinated biphenyls (PCBs), pesticides (e.g., dichlorodiphenyltrichloroethane—DDT), and human sewage. Many of these toxins such as PCBs and

DDT do not degrade for hundreds of years and can concentrate in the sediment and in

the tissues of local aquatic animals. Sources of toxins into estuaries include industrial

discharges; runoff from lawns, streets, and farmlands; and discharges from sewage

treatment plants. The estuary’s own sediment can also serve as a source, as sediment

contains years of toxic deposits. Other toxic substances are deposited into estuaries

from the atmosphere. Mercury vapor and lead particles from industrial sources enter

estuaries from the atmosphere as rain, snow, or dry particles. All toxins can affect an

estuary’s biological structure and populations. Humans, in turn, can be harmed by

consuming bottom-dwelling organisms such as shellfish that are exposed to contaminated sediment as well as through exposure to contaminated water.

Testing for many of these toxins requires specialized equipment and expertise

beyond the means of most volunteer monitoring programs. Nonetheless, it is important to understand the sources of toxins and the role they play in estuaries. Volunteers

can provide valuable assistance with research projects by providing local knowledge

of a watershed and potential sources of toxic compounds and by collecting fish and

invertebrates for laboratory analysis.

This chapter reviews some of the toxic substances found in our nation’s estuarine

ecosystems, especially heavy metals, pesticides, PCBs, and PAHs, and introduces

some testing techniques for toxins.

Overview
12-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 12: Toxins Unit One: Chemical Measures

There are two general classes of toxic

pollutants found in estuaries—metals and

organic compounds. Toxic metals include

mercury, lead, cadmium, chromium, and

copper. Some of these metals (e.g., copper)

are required in small concentrations for

metabolic processes but are toxic at higher

levels. Organic compounds of interest include

PAHs and several synthetic ones that are no

longer produced, such as PCBs and DDT

(USEPA, 1996). Other organic toxins of

concern are biotoxins that are produced by

harmful algal blooms (see Chapter 19). This

chapter focuses on the more traditional

organic compounds.

Sources of toxic substances include surface

water from municipal and industrial

discharges, runoff (e.g., from lawns, streets,

and farmlands), and atmospheric deposition.

Lifespan of Toxins

How long pollutants remain in estuaries

depends on the nature of the compound. Some

pollutants bind to particles and settle, while

others remain water soluble. Another factor is

the flushing rate within the estuary. Many

pollutants, including DDT and PCBs, have

been banned in the United States since the

1970s, but are very chemically stable and

persist in benthic sediment long after the

pollution source has abated. ■

Toxins in Estuaries

Toxicity

Toxins can affect the animals in an

estuarine ecosystem through acute or

chronic toxicity. Organisms suffer acute

toxicity when exposure levels result in

death within 96 hours. Lethal doses differ

for each toxin and species, and are

influenced by the potency and concentration of the toxin. Chronic toxicity—

also referred to as sub-lethal toxicity—

does not result in death (at exposures of at

least 96 hours), but can cause impairment

to aquatic animals, organ damage and

failure, gastro-intestinal damage, and can

affect growth and reproduction.

Why Monitor Toxins?

Monitoring for the presence of toxins

provides information on possible effects to an

estuary’s community structure and

populations. Human health is another

important reason for monitoring. Bottomdwelling organisms, like shellfish, can

accumulate these metals and chemicals in

their tissues, making them a potential risk to

human health when consumed. When high

concentrations of chemical contaminants are

found in local fish and wildlife, state officials

issue consumption advisories for the general

population as well as for sensitive

subpopulations such as pregnant women.

Advisories include recommendations to limit

or avoid consumption of certain fish and

wildlife species from specific bodies of

water. ■
12-3

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 12: Toxins

Though there are many toxic substances

found in our nation’s estuarine ecosystems,

the categories of biggest concern are: heavy

metals, pesticides, PCBs, and PAHs (USEPA,

1996). 

Heavy Metals

Some toxic metals, such as copper and zinc,

are needed in trace amounts for metabolism

but are toxic in higher levels. Others, such as

mercury, lead, chromium, and cadmium, have

no known metabolic function. Their presence

may prompt state officials to restrict water

use, close shellfish waters, or issue fish

consumption advisories. Generally, the three

metals most closely monitored are mercury,

copper, and lead because of their adverse

effects on human health. 

Mercury

Mercury is distributed throughout the

environment from natural sources and from

human activities. Sources of mercury from

human activities (also called anthropogenic

sources) include solid waste incineration and

coal combustion facilities for electricity.

Together, they contribute approximately 87

percent of the emissions of mercury in the

United States. Other sources of mercury

include municipal wastewater treatment plants

and mining and industrial sources, such as

smelting, pulp mills, paper mills, leather

tanning, electroplating, chemical

manufacturing, and cement production. In

addition, mercury is deposited in surface

waters through runoff from its natural

occurrence in rocks and soils as well as from

The Role of Toxins in the Estuary Ecosystem

Accumulation and Amplification 

of Toxins—Definitions

Biological accumulation

(bioaccumulation)—The uptake and

storage of chemicals (e.g., DDT, PCBs)

from the environment by animals and

plants. Uptake can occur through feeding

or direct absorption from water or

sediments. 

Biological amplification (also called

bioamplification, biomagnification or

bioconcentration)—The concentration of a

substance as it “moves up” the food chain

from one consumer to another (Figure 

12-1). The concentration of chemical

contaminants (e.g., DDT, PCBs, methyl

mercury) progressively increases from the

bottom of the food chain (e.g., phytoplankton, zooplankton) to the top of the

food chain (e.g., fish-eating birds such as

cormorants).

Toxin in

fish-eating

birds

Toxin in

large fish

Toxin in small fish

Toxin in plankton

Toxin in water

Figure 12-1. Biological amplification. Chemical concentrations progressively

increase from lower to upper levels of the food chain.
12-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 12: Toxins Unit One: Chemical Measures

atmospheric deposition of

volatile compounds from

wetlands (USEPA, 1999c).

Methylmercury is the

chemical form or “species”

that bioaccumulates in the

tissue of animals and

bioamplifies in food chains.

Mercury poisoning through

consumption of

methylmercurycontaminated food results in

such adverse central nervous system effects as

impairment to peripheral vision and mental

capabilities, loss of feeling, and—at high

doses—seizures, severe neurological

impairment, and death. Methylmercury has also

been shown to be a developmental toxicant,

causing subtle to severe neurological effects in

children. 

Methylmercury makes up 90-100 percent of

the mercury found in most adult fish. It binds to

proteins and is found primarily in fish muscle

(fillets). Concentrations of total mercury in fish

are approximately 10,000 to 100,000 times

higher than the concentrations of total mercury

found in the surrounding waters. 

Mercury contamination is one of the leading

reasons that fish consumption advisories are

issued in the United States. These advisories

inform the public that concentrations of

mercury have been found in local fish at levels

of public health concern. State advisories

recommend either limiting or avoiding

consumption of certain fish from specific

waterbodies (USEPA, 1999c).

Lead

Lead is used by the ton in products such as

batteries, ammunition, solder, pipes, and in

building construction. Lead poisoning is

associated with kidney damage, anemia, and

damage to the central nervous system. Of

greatest concern are the dangers of lead

poisoning to children, who can suffer

permanent physical and mental impairments.

Cadmium

Cadmium is another heavy metal of concern

because it can cause kidney and bone damage

to people who suffer long-term chronic

exposure to it. Sources of cadmium into the

environment from human activities are mainly

from the mining, extraction, and processing of

copper, lead, and zinc. Other sources can

include solid waste incineration, reprocessing

of galvanized metal, and sewage sludge.

Cadmium can also be found in some batteries,

fertilizers, tires, and many industrial processes.

Copper

Copper is an essential nutrient, required by

the body in very small amounts. However, the

U.S. Environmental Protection Agency has

found copper to potentially cause stomach and

intestinal distress, liver and kidney damage,

and anemia, depending on the level and term

of exposure. Persons with certain diseases

may be more sensitive than others to the

effects of copper contamination.

Copper releases to land and water are

primarily from smelting industries. Municipal

incineration may also produce copper. Copper

is also widely used in household plumbing

materials.

Chromium

Depending on the level and term of

exposure, chromium has the potential to cause

skin irritation, ulcers, dermatitis, or damage to

liver, kidney, circulatory, and nerve tissues.

Though widely distributed in soils and

plants, chromium is rare in natural waters.

The two largest sources of chromium

emission in the atmosphere are chemical

manufacturing industries and natural gas, oil,

and coal combustion. Chromium may also

reach waterways via:

• road dust; 

• cement-producing plants; 

• the wearing down of asbestos brake

linings from automobiles or similar

asbestos sources; 

Toxins in the water can

make estuaries and

other waterbodies

unsafe for fishing or

swimming (photo by 

R. Ohrel).
12-5

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 12: Toxins

• municipal refuse and sewage sludge

incineration; 

• automotive catalytic converter exhaust; 

• emissions from cooling towers that use

chromium compounds as rust inhibitors;

• waste waters from electroplating, leather

tanning, and textile industries; and

• solid wastes from chemical

manufacture.

Pesticides

Another major category of toxins in

estuaries is pesticides. Most of them will

break down into nontoxic chemicals within a

few days of application. Others are banned

because they can persist for decades.

Pesticides are developed to eliminate pests

such as weeds (herbicides), insects

(insecticides), rodents (rodenticides), fungi

(fungicides), and other organisms that are

considered undesirable.

Two of the more persistent pesticides are

DDT and its breakdown product and closely

related compound, DDD (dichlorodiphenyldichloroethane). They are both in a class of

pesticides called organochlorines. These

pesticides destroy living cells and affect the

nervous system of organisms. DDT is a highly

toxic, broad-spectrum poison that is capable

of killing many different species. It was used

extensively in the 1940s, 1950s, and 1960s

because it was cheap to produce, effective,

and not harmful to humans. For these reasons,

it continues to be used in developing countries

to eradicate the mosquito that transmits

malaria. DDT was banned in the U.S. in 1972

because of its effects on wildlife, but it

continues to be measured in sediment and in

aquatic animals. In fact, buried sediments may

be a large and continuing source of DDT

compounds due to mixing processes such as

flooding, dredging activities, and the

disturbing of sediment by animals (called

bioturbation), as well as other mechanisms.

Polychlorinated Biphenyls (PCBs) and

Polycyclic Aromatic Hydrocarbons (PAHs)

PCBs are another class of banned synthetic

organic chemicals comprising 209 individual

chlorinated biphenyl compounds. Similar to

DDT, PCBs are resistant to biological and

chemical degradation and can persist in the

environment for decades. There are no known

natural sources of PCBs. Millions of metric

tons of PCBs were used as solvents and in the

electronic industry as insulators for

transformers. Most PCBs are soluble in fats;

therefore, they accumulate in the tissues of

animals. Once incorporated into an animal’s

fat, PCBs will stay there and cannot be

excreted. They are rapidly accumulated by

aquatic organisms, becoming amplified in the

food chain when animals eat PCB-contaminated organisms. PCB concentrations in fish

at the top of the food chain can be 2,000 to

more than a million times higher than the

concentrations found in the surrounding

waters (USEPA, 1999d).

While the manufacture and use of PCBs

have been banned in the U.S. since 1976, the

sediment of many estuaries can have high

levels of PCB contamination, and PCBs can

continue to enter estuaries from leaking

shoreside landfills or from improper disposal.

PCBs in the sediment can reenter the water

column though natural processes and dredging

activities. Although PCBs are declining in the

environment, health concerns are still

warranted.

Recent findings indicate that susceptible

populations (e.g., certain ethnic groups, sport

anglers, the elderly, pregnant women,

children, fetuses, and nursing infants)

continue to be exposed to PCBs via fish and

wildlife consumption (USEPA, 1999d).

Exposure to PCB compounds involves

different levels of harmful risks. There is

much interest in determining if PCBs are

endocrine disrupters—chemicals that can

mimic, block, or otherwise disrupt the body’s

hormones. Some have been shown to act as
12-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 12: Toxins Unit One: Chemical Measures

hormone disrupters in wildlife and possibly in

laboratory animals. Human health studies

indicate that eating fish containing PCBs can

lead to significant health consequences

including: 

• reproductive dysfunction; 

• deficiencies in neurobehavioral and

developmental behavior, especially in

newborns and school-aged children; 

• other systemic effects (e.g., liver

disease, diabetes, effects on the thyroid

and immune systems); and 

• increased cancer risks (e.g., nonHodgkin’s lymphoma) (USEPA, 1999d).

Polycyclic aromatic hydrocarbons, PAHs,

are the byproducts of oil burning. They are

carcinogenic (cancer causing) and mutagenic

(change cell growth). They are also produced

by burning coal and wood. They enter

estuaries from leaking gas storage tanks, road

runoff, sewage plants, industrial and

municipal discharges, oil spills, and bilge

water discharges. Creosote applied to wharf

pilings also contains PAHs.

Other Notable Toxins

In addition to the toxins discussed above,

there are many others that enter estuaries and

affect their wildlife. Some of these include:

Dioxin

Dioxin, a byproduct of bleaching paper with

chlorine, is associated with birth defects in

humans. Chlorine combines with lignins

(natural binders of wood fiber) to produce

dioxin.

Tributyltin (TBT)

TBT, an antifouling paint additive used on

boats and in marinas, is a fat-loving

compound (lipophilic) that accumulates in the

tissue of animals, and amplifies in the food

chain. Contributions of TBT arise almost

exclusively from anti-fouling bottom paints

that are applied to boat hulls to retard the

growth of barnacles and other fouling

organisms. The greatest release of trace

metals occurs when the paint is fresh or after

hull cleaning when new layers of paint are

exposed. Over the last few years, increasing

regulation and controls have attempted to

reduce emissions from this source to estuary

waters. For example, TBT can no longer be

used on small craft, but is used on oceanbound tankers. Nonetheless, while the use of

TBT is restricted, it is still in use and

accumulates in harbor sediments.

Household chemicals, paints, cleaning

chemicals, etc.

There are tens of thousands of chemicals

used in industrial processes and in our homes.

Little is known about their effects on aquatic

life, how concentrated they are in estuaries,

how long they persist in aquatic environments,

or their interaction with each other. ■

Some Toxins Are from 

Biological Processes

Excessive algae growth can result in brown

and red tides and other harmful blooms.

Harmful algal blooms excrete biotoxins

that can be hazardous to shellfish, fish, and

humans. See Chapter 19 for more

information.
12-7

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 12: Toxins

Toxic metal and organic pollutants are

found in low concentrations in water—on the

order of parts-per-billion and parts-per-trillion

levels. But concentrations in the sediment are

higher and range in the parts-per-million and

parts-per-billion levels. Because of these low

levels, collecting water and sediment samples

for toxin analysis involves a high degree of

rigor and training to limit inadvertent

contamination of the sample. Sources of

contamination include the polyethylene bottle,

as well as the handling of the bottle. Unless

there is a clear justification and rigorous

oversight, volunteer monitoring programs

are discouraged from collecting samples for

toxin analysis. However, it is important that

volunteer programs understand the general

process of sampling for toxins and testing

their impact. 

Testing for the presence of toxic substances

(metals and toxic chemical compounds) in

estuary water and sediment usually requires a

laboratory with expensive equipment, such as

a mass spectrometer, high performance liquid

chromatography, or atomic absorption

spectrophotometer. Some toxins are in minute

quantities and require a concentration step,

such as organic extractions, to be analyzed.

One method scientists use to analyze the

effects of a toxic substance on living

organisms is called a bioassay, or biological

assay. A bioassay is a controlled experiment

using a change in biological activity as a

qualitative or quantitative means of analyzing

a material response to a pollutant. Depending

on the test, microorganisms, planktonic

animals, or live fish can be used as test

organisms.

Scientists also look for biochemical

indicators of contaminants by studying

animals called biomarkers. They look for

DNA damage in blood cells and the presence

of stress proteins, which are produced in

response to a wide variety of contaminants,

including trace metals and organic pollutants.

Volunteers may be able to assist with

collecting fish and invertebrates to be used in

the chemical analysis of tissue, or under a

very high degree of training assist with the

collection of sediment and water samples to

be tested for toxicity. In some cases,

volunteers collect shellfish and send them to a

laboratory for tissue analysis. See Chapter 19

for more information.

Volunteer water quality monitoring

programs interested in monitoring for toxins

are recommended to work with a local college

or laboratory which has the necessary

equipment and knowledge. Any such study

should carefully follow established protocols

for analysis and testing (see, for example,

APHA, 1998).

Volunteers can also assist with a field

survey to identify potential sources of toxins

in an estuary. See Chapter 7 for more

information on field observations.

It should be noted that conventional toxicity

tests and chemical analyses are rarely

sufficient to identify the cause or sources of

toxicity. Multiple contaminants are usually

present in a toxic sample, and many of the

contaminants may be at elevated

concentrations. There are other important

factors that influence toxicity, such as

sediment organic carbon content or the size of

sand grains.

Field test kits are available for some of the

heavy metals and other pollutants that can be

used in preliminary measurements. For

example, one kit measures copper in estuaries

that may exist as a soluble salt or as

suspended solids. Test kits are also available

for zinc, chlorine, chromate, iron, chloride,

silica, and cyanide. Field test kits vary greatly

in their detectable range and cost between $15

and $450. ■

Sampling Considerations
12-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 12: Toxins Unit One: Chemical Measures

Over the past 30 years,

scientists have collected

a large amount of

convincing information

demonstrating that air

pollutants can be

deposited on land and

water—sometimes at

great distances from their

original sources—and

can contribute to

declining estuarine water quality. This is

called atmospheric deposition. Pollutants

released into the air are carried by wind

patterns away from their place of origin.

These pollutants come from manmade or

natural sources of emissions. For example, up

to 25% of the mercury emitted worldwide is

released naturally as part of the global

mercury cycle. 

Presently, atmospheric deposition

monitoring by volunteers is in its early stages.

In the future, there may be a role for

volunteers to monitor the amount of toxins

that are deposited from the atmosphere into

estuaries. See Chapter 10 for more

information on atmospheric deposition. ■

Atmospheric Deposition of Toxins

References and Further Reading

Portions of this chapter were excerpted and adapted from:

Miller, G.T. 1999. Environmental Science. Wadsworth Publishing Company. Belmont, CA.

Southern California Coastal Water Research Project. 1999. FY 1999/2000 Research Plan.

U.S. Environmental Protection Agency (USEPA). 1996. Environmental Indicators of Water

Quality in the United States. EPA 841-R-96-002. Office of Water, Washington, DC.

U.S. Environmental Protection Agency (USEPA). 1998. Estuaries and Your Coastal Watershed.

EPA-842-F-98-009. Office of Water, Washington, DC. Web site:

http://www.epa.gov/owowwtr1/oceans/factsheets/fact5.html. 

U.S. Environmental Protection Agency (USEPA). 1999a. Guidance for Assessing Chemical

Contaminant Data for Use in Fish Advisories. Vol. 2, 3rd ed. “Risk Assessment and Fish

Consumption Limits.” EPA 823-B-99-008. Office of Water, Washington, DC. 

U.S. Environmental Protection Agency (USEPA). 1999b. Fact Sheet: Update: National Listing

of Fish and Wildlife Advisories. EPA-823-F-99-005. Office of Water, Washington, DC. 

U.S. Environmental Protection Agency (USEPA). 1999c. Fact Sheet: Mercury Update: Impact

on Fish Advisories. EPA-823-F-99-016. Office of Water, Washington, DC.

U.S. Environmental Protection Agency (USEPA). 1999d. Fact Sheet: Public Health Implications

of Exposure to Polychlorinated Biphenyls (PCBs). EPA-823-F-99-019. Office of Water,

Washington, DC.

Pollutants released 

into the air can be

introduced to the

estuary through

atmospheric deposition 

(photo by R. Ohrel).
12-9

Volunteer Estuary Monitoring: A Methods Manual

Unit One: Chemical Measures Chapter 12: Toxins

Other references:

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L.S. Clesceri, A.E. Greenberg, A.D. Eaton (eds). Washington, DC.

Maine Coastal Program. 1998. The Estuary Book. State Planning Office, 38 State House Station,

Augusta, ME 04333.

National Safety Council’s Environmental Center. 1998. Coastal Challenges: A Guide to Coastal

and Marine Issues. Prepared in conjunction with Coastal America. 

Web site: http://www.nsc.org/ehc/guidebks/coasttoc.htm

Web sites:

Restore America’s Estuaries: http://www.estuaries.org/estuarywhat.html.

Atmospheric Deposition

National Estuary Program (NEP): http://www.epa.gov/owow/estuaries/airdep.htm
12-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 12: Toxins Unit One: Chemical Measures
UnitPhysical Measur Twoes

Temperature • Salinity • Turbidity and Total Solids • Marine Debris
Photos (l to r): U.S. Environmental Protection Agency, R. Ohrel, S. Schultz, P. Bergstrom
Chapter13 Temperature

Water temperature is closely connected to many biological and chemical processes

in the estuary. For this reason, and because it is easily measured, temperature is

commonly monitored by volunteer groups using thermometers or meters.
Photos (l to r): R. Ohrel, R. Ohrel, Tillamook Bay National Estuary Project and Battelle Marine Sciences Lab, U.S. Environmental Protection Agency
13-1

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 13: Temperature

Water temperature is closely connected to many biological and chemical processes

in the estuary. For this reason, and because it is easily measured, temperature is

commonly monitored by volunteer groups using thermometers or meters.

This chapter explains the significance and variability of estuarine water

temperature and provides steps for collecting temperature data.

Overview
13-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 13: Temperature Unit Two: Physical Measures

Temperature, probably the most easily

measured parameter, is a critical factor

influencing several aspects of the estuarine

ecosystem. It influences biological activity

and many chemical variables in the estuary.

The Role of Temperature in 

the Estuarine Ecosystem

Temperature plays many roles in the

estuary. As water temperature increases, for

example, the capacity of water to hold

dissolved oxygen becomes lower. Water

temperature also influences the rate of plant

photosynthesis, the metabolic rates of aquatic

organisms, and the sensitivity of organisms to

toxic wastes, parasites, and diseases (USEPA,

1997).

Many species regulate the timing of

important events, such as reproduction and

migration, according to specific water

temperatures. Optimal temperatures (which

vary with the species and their life stage)

allow organisms to function at maximum

efficiency. The slow change of temperature

that comes with the seasons permits

organisms to acclimate, whereas rapid shifts

may adversely affect plants and animals.

Temperature shifts of more than 1°-2°C can

cause thermal stress and shock (Campbell and

Wildberger, 1992). Long-term temperature

changes can affect the overall distribution and

abundance of estuarine organisms.

Throughout the winter, temperatures remain

fairly constant from top to bottom. In spring

and summer, the uppermost layer of an

estuary grows warmer and mixing between

this surface water and the cooler bottom water

slows. As air temperatures cool through the

autumn, the surface water becomes

increasingly cold and increases in density. The

surface water mass ultimately sinks when its

density becomes greater than that of the

underlying water mass. As the surface water

moves down, mixing occurs and nutrients

from the bottom are redistributed toward the

surface. This introduction of nutrients to

surface waters fuels phytoplankton growth

(see Chapters 10 and 19). 

Temperature is not generally constant from

the water surface to the bottom. An estuary’s

water temperature is a function of: 

• depth; 

• season; 

• amount of mixing due to wind, storms,

and tides; 

• degree of stratification (layering) in the

estuary; 

• temperature of water flowing in from

the tributaries; and 

• human influences (e.g., release of urban

stormwater, warm water discharged

from power plants). ■

Why Monitor Temperature?

Sampling Considerations

Where to Sample

Because temperatures change according to

the many variables listed above, it is often

helpful to measure water temperature

throughout the water column and at different

surface locations. By collecting samples at

different depths, thermal layers within the

estuary can be determined. This information,

in turn, can be useful for analyzing other

environmental parameters.

HELPFUL HINT

Temperature can only be measured at the

monitoring site. If samples are to be taken

to a laboratory for analysis, temperature

should first be measured in the field.
13-3

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 13: Temperature

General procedures for measuring

temperature are presented in this section for

guidance only. Monitors should consult with

the instructions that come with their

sampling and analyzing instruments. Those

who are interested in submitting data to

water quality agencies should also consult

with the agencies to determine acceptable

equipment, methods, quality control

measures, and data quality objectives (see

Chapter 5).

Before proceeding to the monitoring site and

collecting samples, volunteers should review

the topics addressed in Chapter 7. It is critical

to confirm the monitoring site, date, and time;

have the necessary monitoring equipment and

personal gear; and understand all safety

considerations. Once at the monitoring site,

volunteers should record general site

observations, as discussed in Chapter 7.

STEP 1: Check equipment. 

Check to make sure that no separation has

occurred in the thermometer liquid before

each use. 

If you are using a thermometer and not measuring directly in the water, bring a large (at

least 2-gallon) clear container that can hold the

sample. This will facilitate thermometer reading.

When to Sample

As with other water quality variables, 

temperature should be measured at the same

location and time of day each time volunteers

collect data.

Choosing a Sampling Method 

Water temperature is measured with a thermometer or meter. Alcohol-filled thermometers

are less hazardous, when broken, than mercuryfilled thermometers, making them the better

option. Under field conditions, using a thermometer armored in plastic or metal will minimize breakage problems.

Some meters used to measure other parameters, such as pH or dissolved oxygen, also measure temperature and can be used instead of a

thermometer. 

Volunteer monitors usually take a single temperature reading while they collect other water

quality data at their monitoring sites. While the

single reading is useful, it does not fully provide details about daily trends. Temperature

data loggers, which record data at regular intervals (usually hourly), could be deployed at

selected monitoring sites. These instruments are

able to continuously record data for up to

months at a time. The data can then be downloaded directly into a computer database. As the

costs of data loggers decline, they may become

attractive options for volunteer programs. ■

Thermometer Accuracy

To assure accuracy, check the thermometer

against a National Institute of Standards

and Technology (NIST) certified

thermometer at least once a year. 

Confirm the thermometer’s accuracy in

several samples of water of varying

temperatures. Your county health department or the state department of environmental protection may lend an NIST

thermometer to the program for these

important periodic checks.

Reminder!

To ensure consistently high quality data,

appropriate quality control measures are

necessary. See “Quality Control and

Assessment” in Chapter 5 for details.

How to Monitor Temperature 
13-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 13: Temperature Unit Two: Physical Measures

STEP 2: Measure air temperature.

Chapter 7 specifies air temperature as one

of the general observations that should be

made at each monitoring site. Air temperature

can be measured with the same thermometer or

meter used for reading water temperature. Prior

to measuring water temperature, allow the thermometer or meter to equalize with the ambient

or surrounding air temperature for three to five

minutes. Make sure the thermometer is out of

direct sunlight to avoid a false high reading.

Record the air temperature on the data sheet

before measuring the water temperature.

STEP 3: Measure water temperature.

The following section describes two procedures to measure water temperature. If measuring temperature in shallow water or at the surface, follow Procedure A. If measuring temperature from a collected water sample, follow

Procedure B.

Procedure A—Measuring temperature directly

in shallow water or at the water surface:

• Place the thermometer or meter probe in

the water at least 4 inches below the surface or halfway to the bottom (if in very

shallow water). 

• If using a thermometer, wait until it

reaches a stable temperature (3-5 minutes). If using a meter, allow it to reach a

stable reading.

• If possible, read the temperature with the

thermometer bulb beneath the water surface. Otherwise, quickly remove the thermometer and read the temperature.

• Record the temperature on the field data

sheet, using the scale (°C or °F) required

by the program (Figure 13-1).

• If the meter probe has a long cable, you

may measure temperature at different

depths.

Procedure B—Measuring temperature from a

collected water sample:

• Make sure the sample holds at least two

gallons so that the water remains unaffected by the temperature of the thermometer and the air. The volunteer can

use this same sample for many other typical water quality monitoring tests.

• Quickly immerse the thermometer or

meter in the water sample.

• If using a thermometer, wait until it

reaches a stable temperature (3-5 minutes). If using a meter, allow it to reach a

stable reading.

• If possible, read the temperature with the

thermometer bulb beneath the water surface. Otherwise, quickly remove the thermometer and read the temperature.

• Record the temperature on the field data

sheet, using the scale (°C or °F) required

by the program (Figure 13-1).

STEP 4: Clean up and send off data.

Thoroughly clean all equipment for proper

storage. 

Make sure the data sheets are complete and

accurate. Volunteers should make a copy of the

completed data sheets before turning them in to

the laboratory, program manager, or designated

drop-off point. ■

212

200

190

180

170

160

150

140

130

120

110

100

90

80

70

60

50

40

32

100

90

80

70

60

50

40

30

20

10

0

 ̊F  ̊C

°C = x (°F – 32) 5

9

°F = x °C + 32 9 (5 )

Figure 13-1. Temperature

conversion scale.
13-5

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 13: Temperature

References and Further Reading

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L. S. Clesceri, A. E. Greenberg, A. D. Eaton (eds). Washington, DC.

Campbell, G., and S. Wildberger. 1992. The Monitor’s Handbook. LaMotte Company,

Chestertown, MD. 71 pp.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: 

A Methods Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.
13-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 13: Temperature Unit Two: Physical Measures
Chapter 14Salinity

Because of its importance to estuarine ecosystems, salinity (the amount of

dissolved salts in water) is commonly measured by volunteer monitoring programs. 
Photos (l to r): U.S. Environmental Protection Agency, R. Ohrel, The Ocean Conservancy, P. Bergstrom
14-1

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 14: Salinity

Because of its importance to estuarine ecosystems, salinity (the amount of

dissolved salts in water) is commonly measured by volunteer monitoring

programs. This chapter discusses the role of salinity in the estuarine environment

and provides steps for measuring this water quality variable.

Overview
14-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 14: Salinity Unit Two: Physical Measures

Salinity is simply a measure of the amount of

salts dissolved in water. An estuary usually

exhibits a gradual change in salinity throughout

its length, as fresh water entering the estuary

from tributaries mixes with seawater moving in

from the ocean (Figure 14-1). Salinity is usually

expressed in parts per thousand (ppt) or 0

/00. 

The fresh water from rivers has a salinity of

0.5 ppt or less. Within the estuary, salinity levels are referred to as oligohaline (0.5-5.0 ppt),

mesohaline (5.0-18.0 ppt), or polyhaline (18.0-

30.0 ppt). Near the connection with the open

sea, estuarine waters may be euhaline, where

salinity levels are the same as the ocean at more

than 30.0 ppt (Mitsch and Gosselink, 1986). 

Generally, salinity increases with water depth

unless the estuarine water column is well

mixed. Salinity, along with water temperature,

is the primary factor in determining the stratification of an estuary. When fresh and salt water

meet, the two do not readily mix. Warm, fresh

water is less dense than cold, salty water and

will overlie the wedge of seawater pushing in

from the ocean. Storms, tides, and wind, however, can eliminate the layering caused by salinity and temperature differences by thoroughly

mixing the two masses of water. The shape of

the estuary and the volume of river flow also

influence this two-layer circulation. See

Chapter 2 for more information. 

Role of Salinity in the Estuarine

Ecosystem

Salinity levels control, to a large degree, the

types of plants and animals that can live in

different zones of the estuary. Freshwater

species may be restricted to the upper reaches

of the estuary, while marine species inhabit the

estuarine mouth. Some species tolerate only

intermediate levels of salinity while broadly

adapted species can acclimate to any salinity

ranging from fresh water to seawater. 

Salinity measurements may also offer clues

about estuarine areas that could become afflicted by salinity-specific diseases. In the

Chesapeake and Delaware bays, for example,

pathogens infecting oysters are restricted to sections that fall within certain salinity levels.

Drastic changes in salinity, such as those due to

drought or storms, can also greatly alter the

numbers and types of animals and plants in 

the estuary. 

Another role played by saline water in an

estuary involves flocculation of particles.

Flocculation is the process of particles aggregating into larger clumps. The particles that

enter an estuary dissolved in the fresh water of

rivers collide with the salt water, and may flocculate or clump together and increase turbidity

(Figure 14-2).

Salinity is often an important factor when

monitoring many key water quality variables.

For example:

• Most dissolved oxygen meters require

knowledge of the salinity content in

order to calibrate the meter properly.

• If you are interested in converting the

dissolved oxygen concentration (usually

expressed as mg/l or parts per million) to

About Salinity

(During

Low Flow

Conditions)

Non-Tidal

Fresh Water

Tidal

Fresh Water

Oligohaline

Mesohaline

Polyhaline

Average

Annual

Salinity Tidal Limit

OCEAN

Euhaline < 30.0 ppt

< 18.0 ppt

< 5.0 ppt

< 0.5 ppt

(Marine)

Figure 14-1. Estuarine

salinity slowly increases

as one moves away

from freshwater sources

and toward the ocean.
14-3

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 14: Salinity

Salinity will fluctuate with movement of the

tides, dilution by precipitation, and mixing of

the water by wind. There are also seasonal

differences in salinity. 

Season and Weather

Environmental conditions vary with the

seasons, and salinity levels can reflect those

variations. During wet weather periods and

during the spring thaw in colder regions, more

fresh water enters the estuary, so salinity is

lower at these times. On the other hand, dry

weather periods mean less fresh water

entering the estuary, so higher salinity levels

may be found. Another way the seasons

influence an estuary’s salinity involves the

mixing of fresh water and salt water. Seasonal

storms help mix estuarine waters and serve to

decrease the vertical salinity and temperature

gradients in the estuary. 

Choosing a Sampling Method

Salinity can be measured either by physical

or chemical methods. Physical methods use

conductivity, density, or refractivity. The

physical methods are quicker and more

convenient than the chemical methods. The

chemical methods determine chlorinity (the

chloride concentration), which is closely

related to salinity.

Conductivity 

Conductivity is a measure of the ability of

water to pass an electrical current.

Conductivity in water is affected by the

presence of inorganic dissolved solids such as

chloride, nitrate, sulfate, and phosphate

anions (ions that carry a negative charge) or

sodium, magnesium, calcium, iron, and

aluminum cations (ions that carry a positive

charge). As the concentration of salts in the

water increases, electrical conductivity rises—

the greater the salinity, the higher the

conductivity. Organic compounds like oil,

phenol, alcohol, and sugar do not conduct

electrical current very well and, therefore,

have a low conductivity when in water.

Conductivity is also affected by temperature:

the warmer the water, the higher the

conductivity. For this reason, conductivity is

extrapolated to a standard temperature (25°C). 

Conductivity is measured with a probe and

a meter. Conductivity meters require

temperature correction and accurate

percent saturation (amount of oxygen in

the water compared to the maximum it

could hold at that temperature), you must

take salinity into account. As salinity

increases, the amount of oxygen that

water can hold decreases.

• If you use a meter to measure pH, the

techniques are the same whether you

are testing salt or fresh water.

However, if you measure with an

electronic colorimeter, you must use a

correction factor (available from the

manufacturer) to compensate for the

effects of salinity. ■

Fresh Water

Salt Water

Sampling Considerations

Figure 14-2. Turbidity increases when fresh water meets with salt water.
14-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 14: Salinity Unit Two: Physical Measures

calibration can be difficult. The cost of these

meters ranges from $500 to $1,500. Voltage is

applied between two electrodes in a probe

immersed in the sample water. The drop in

voltage caused by the resistance of the water

is used to calculate the conductivity per

centimeter. The meter converts the probe

measurement to micromhos per centimeter

and displays the result for the user. 

Some conductivity meters can also be used

to test for total dissolved solids and salinity.

The total dissolved solids concentration in

milligrams per liter (mg/l) can also be

calculated by multiplying the conductivity

result by a factor between 0.55 and 0.9, which

is empirically determined (see APHA, 1998).

Meters should also measure temperature

and automatically compensate for temperature

in the conductivity reading. Conductivity can

be measured in the field or the lab. In most

cases, it is probably better if the samples are

collected in the field and taken to a lab for

testing. In this way, several teams of

volunteers can collect samples simultaneously. If it is important to test in the field,

meters designed for field use can be obtained

for around the same cost mentioned above. 

Density

As water becomes saltier, its

weight increases although its

volume does not measurably

rise. Since salt water is denser

than fresh water, this change

of weight results in a greater

specific gravity. The volunteer can calculate

salinity by measuring a water sample’s

specific gravity. This is done with a

hydrometer (Figure 14-3).

Hydrometers are a fairly simple and

inexpensive means of obtaining salinity.

Specific gravity hydrometers cost from $13 to

$25 (although professional sets can cost much

more), and a hydrometer jar costs about $13

to $15, although you can also use a large,

clear jar that is deep enough to float the

hydrometer.

Because hydrometers measure specific

gravity, the presence of suspended solids can

raise hydrometer readings and result in a

salinity measurement that is higher than the

true value. This has especially been shown in

low salinity areas (Bergstrom, 1997;

Bergstrom, 2002). Volunteer programs,

therefore, should consider their accuracy and

precision requirements before electing to use

a hydrometer.

Refractivity

Refractometers (Figure 14-4) are used to

measure substances dissolved in water, using

the principle of light refraction through

liquids. The more dissolved solids in water,

the slower light travels through it.

Refractometers measure the change in the

direction of light as it passes from air into

water. Salinity and temperature both affect 

the index. 

Refractometers use a scale to quantify the

effect that dissolved solids in water have on

light. Using a refractometer is simple. It

works with ambient light, and no batteries 

are required. Such instruments cost from 

$150 to $350.

Chlorinity 

Salinity is related to chlorinity, and this

method calculates salinity based on the

quantity of chloride ions in the sample.

Salinity kits based on testing chloride ions

cost about $40 for 50 tests.

The chlorinity method uses titration with

.005

.010

.015

.020

.025

.030

.035

.040

.045

.050

.055

.060

.0651.0 00 1.0 75 Specific Gravity

Figure 14-3.

Hydrometer.

Salt water is

denser than

fresh water and

has a greater

specific gravity.

Volunteers can

calculate salinity

by measuring a

water sample’s

specific gravity

with a

hydrometer.

Daylight plate

Prism

Eyepiece

Salinity Specific

Gravity

015

100

90

80

70

60

50

40

30

20

10

0

40

30

20

10

0

20 C

Figure 14-4. Refractometer.

Salinity can be determined

by a refractometer, which

measures the change in

direction of light as it passes

from air into water. While

not inexpensive, it is very

simple to use.
14-5

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 14: Salinity

General procedures for collecting and

analyzing salinity samples are presented in

this section for guidance only; they do not

apply to all sampling methods. Monitors

should consult with the instructions that

come with their sampling and analyzing

instruments. Those who are interested in

submitting data to water quality agencies

should also consult with the agencies to

determine acceptable equipment, methods,

quality control measures, and data quality

objectives (see Chapter 5).

Before proceeding to the monitoring site and

collecting samples, volunteers should review

the topics addressed in Chapter 7. It is critical

to confirm the monitoring site, date, and time;

have the necessary monitoring equipment and

personal gear; and understand all safety

considerations. Once at the monitoring site,

volunteers should record general site

observations, as discussed in Chapter 7.

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site for each sampling session:

• hydrometer, jar, and hydrometer

conversion table; or

• conductivity meter (plus standard to

check accuracy of meter); or

• refractometer; or

• field kit to test for chloride.

STEP 2: Collect the sample.

If samples will be collected in the

field for later measurement, follow

these collection and storage steps.

See Chapter 7 for information on

cleaning and preparing bottles. 

• Use 200 ml glass or

polyethylene bottles. (NOTE:

Some procedures require

smaller samples. Check with

your lab for their preferred

volume of sample water.)

• Label the bottle with site name, date,

time, data collector, and analysis to be

performed.

• Wearing latex gloves, plunge the bottle

into the water. Fill the bottle completely

and cap tightly.

• Samples may be stored up to 7 days

before analysis (Hach, 1997).

STEP 3: Measure salinity.

The following section describes various

methods to analyze a water sample for

salinity. If analyzing salinity by using a

hydrometer, follow Procedure A. If using a

conductivity meter, use Procedure B. If using

either a silver nitrate or mercuric nitrate

solution. Some kits require conversion of

chlorinity to salinity using a formula, while

others incorporate the formula and give

results directly as salinity. Whichever

chloride analysis process you select, read the

literature to determine if a conversion

formula is needed.

This method is relatively easy to use

although the color change at the endpoint is

sometimes difficult to assess. A white paper

placed behind the titration bottle makes

determination of the endpoint an 

easier task. ■

REMINDER!

To ensure consistently high quality data,

appropriate quality control measures are

necessary. See “Quality Control and

Assessment” in Chapter 5 for details.

How to Measure Salinity

Using a hydrometer.

(photo by P. Bergstrom).
14-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 14: Salinity Unit Two: Physical Measures

a refractometer, follow

Procedure C. If using a

salinity kit based on testing

chloride ions, follow the

directions that come with

the kit.

Procedure A—Measuring

salinity with a hydrometer

• Put the water sample in a hydrometer jar

or a large, clear jar.

• Gently lower the hydrometer into the jar

along with a thermometer. Make sure the

hydrometer and thermometer are not

touching and that the top of the

hydrometer stem (which is not in the

water) is free of water drops. 

• Let the hydrometer stabilize and then

record the specific gravity and

temperature. Read the specific gravity (to

the fourth decimal place) at the point

where the water level in the jar meets the

hydrometer scale. Do not record the value

where the meniscus (the upward

curvature of the water where it touches

the glass) intersects the hydrometer (see

Figure 14-5). 

• Record the specific gravity and the

temperature on your data sheet.

• Use a hydrometer conversion table that

comes with your hydrometer to determine

the salinity of the sample at the recorded

temperature. Record the salinity of the

sample on your data sheet.

Procedure B—Measuring salinity with a

conductivity meter (in field or lab)

• Prepare the conductivity meter for use

according to the manufacturer’s

directions. 

• Use a conductivity standard solution

(usually potassium chloride or sodium

chloride) to calibrate the meter for the

range that you will be measuring. The

manufacturer’s directions should describe

the preparation procedures for the

standard solution. 

• Rinse the probe with distilled or

deionized water. 

• Select the appropriate range on the meter,

beginning with the highest range and

working down. Place the probe into the

sample water, and read the conductivity

of the water sample on the meter’s scale.

If the reading is in the lower 10 percent

of the range that you selected, switch to

the next lower range. If the reading is

above 10 percent on the scale, then record

this number on your data sheet.

• If the conductivity of the sample exceeds

the range of the instrument, you may

dilute the sample with distilled water. Be

sure to perform the dilution according to

the manufacturer’s directions because the

dilution might not have a simple linear

relationship to the conductivity.

• Rinse the probe with distilled or

deionized water and repeat the fourth step

above with the next water sample until

finished.

Procedure C—Measuring salinity with 

a refractometer

• Lift the lid that protects the

refractometer’s specially angled lens. 

• Place a few drops of your sample liquid

on the angled lens, and close the lid.

• Peer through the eyepiece. Results appear

along a scale within the eyepiece. 

• Record the measurement on your data

sheet.

• Rinse the lens with a few drops of

distilled water, and pat dry, being very

careful to not scratch the lens’surface.

1.0020

1.0025

Water

Level

Read at

Water Level

Meniscus

Figure 14-5. Reading the

hydrometer. After letting the

hydrometer stabilize, read

the specific gravity at the

point where the water level

in the jar meets the hydrometer scale. Do not record

the value where the meniscus (the upward curvature of

the water where it touches

the glass) intersects the

hydrometer (redrawn from

LaMotte, 1993).
14-7

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 14: Salinity

STEP 4: Clean up and send off data.

Volunteers should thoroughly clean all

equipment and transport the samples to the

designated lab, if necessary.

Make sure that the data sheet is complete,

legible, and accurate, and that it accounts for 

all samples. Volunteers should make a copy of

the completed data sheet before sending it to

the designated person or agency in case the

original data sheet becomes lost. ■

Portions of this chapter were excerpted and adapted from:

Green, L. 1998. “Let Us Go Down to the Sea—How Monitoring Changes from River to

Estuary.” The Volunteer Monitor 10(2): 1-3.

Hach. 1997. Hach Water Analysis Handbook. 3rd ed. Hach Company. Loveland, CO.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: 

A Methods Manual. EPA 841-B-97-003. Office of Water, Washington, DC. 211 pp.

Other references:

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L.S. Clesceri, A.E. Greenberg, A.D. Eaton (eds). Washington, DC.

Bergstrom, P. 1997. “Salinity by Conductivity and Hydrometer—A Method Comparison.” 

The Volunteer Monitor 9(1):13-15.

Bergstrom, P. 2002. “Salinity Methods Comparison: Conductivity, Hydrometer, Refractometer.”

The Volunteer Monitor 14(1):20-21.

LaMotte Company. 1993. Hydrometer Instructions. Chestertown, MD.

Maine Coastal Program. 1998. The Estuary Book. State Planning Office, 38 State House Station,

Augusta, ME 04333.

Mitsch, W.J., and J.G. Gosselink. 1986. Wetlands. Van Nostrand Reinhold, New York. 539 pp.

References and Further Reading
14-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 14: Salinity Unit Two: Physical Measures
Chapter 15 Turbidity and Total Solids

Natural runoff, water turbulence from storms, and wave action can cause turbidity

of the water. Sediment can also be disturbed by bottom-feeding animals, adding to

the water’s turbidity. Although we often think that clean water is clear, even

unpolluted water can have suspended particles that may lessen its clarity but do

not diminish its quality. Many human activities contribute to increased turbidity,

as discussed in this chapter.
Photos (l to r): G. Carver, K. Register, R. Ohrel, K. Register
15-1

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 15: Turbidity and Total Solids

Measures of turbidity indicate how cloudy or muddy the water is or,

alternatively, the degree of its clarity or translucence. Several types of material

cause water turbidity: 

• suspended soil particles (including clay, silt, and sand); 

• tiny floating organisms (e.g., phytoplankton, zooplankton, and

bacterioplankton); and

• small fragments of dead plants. 

Natural runoff, water turbulence from storms, and wave action can cause

turbidity of the water. Sediment can also be disturbed by bottom-feeding animals,

adding to the water’s turbidity. Although we often think that clean water is clear,

even unpolluted water can have suspended particles that may lessen its clarity but

do not diminish its quality. Human activities, however, exacerbate the clouding.

Sediment runoff from agricultural fields, logging activities, wash from

construction sites and urban areas, and shoreline erosion from heavy boat traffic

and jet skis, among other problems, all contribute to high turbidity. Excessive

algal growth due to the additions of nutrients into an estuary can also affect water

turbidity. High levels of turbidity over long periods of time can greatly diminish

the health and productivity of the estuarine ecosystem.

This chapter explains the role of turbidity in the estuarine ecosystem and

describes some common steps for monitoring it. The measurement of total

solids—particles suspended and dissolved in the water—is also discussed.

Overview
15-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 15: Turbidity and Total Solids Unit Two: Physical Measures

Turbidity is a measure of water

clarity: how much the material

suspended in water decreases the

passage of light through the water.

Suspended materials include soil

particles (clay, silt, and sand), algae,

plankton, and other substances. They

are typically in the size range of 0.004

mm (clay) to 1.0 mm (sand). 

Total solids refer to the matter that is

suspended or dissolved in water.

When a water sample is evaporated,

there is often a residue left in the

vessel—these are the total solids. The

solids in water have different attributes

and sizes. The suspended particles in

water can be retained on a filter with a

2 μm or smaller pore size, while

dissolved solids are small enough to

pass through a filter of that size.

Turbidity and total solids can be useful

indicators of the effects of runoff from

construction, agricultural practices, logging

activity, discharges, and other sources.

Regular monitoring can help detect trends that

might indicate increasing (or decreasing)

erosion in the estuary’s watershed.

Sources of turbidity in estuary waters

include: 

• soil erosion from construction, forestry,

or agricultural sites;

• waste discharge;

• urban runoff;

• eroding stream banks;

• stirred-up bottom sediments from

flooding, dredging, boating and jetskiing activities, or bottom-feeding

animals; and

• excessive algal growth.

Turbidity and total solids often increase

sharply during and immediately following a

rainfall, especially in developed watersheds,

which typically have relatively high

proportions of impervious surfaces such as

rooftops, parking lots, and roads. The flow of

stormwater runoff from impervious surfaces

rapidly increases stream velocity, which

increases the erosion rates of streambanks and

channels. Turbidity can also rise sharply

during dry weather if earth-disturbing

activities are occurring without erosion

control practices in place. 

Sedimentation, where solids settle out of the

water column onto the estuary bottom, is a

priority concern in many estuaries, making

turbidity monitoring an important part of most

volunteer estuary water quality monitoring

programs. As one example, a study of Weeks

Bay, Alabama, found that its watershed

contributed about 22,500 tons of sediment per

year to the bay as a result of agricultural field

runoff (Baldwin County, 1993).

The Role of Turbidity and Total Solids in

the Estuarine Ecosystem

Highly turbid water full of suspended

material has many effects on the estuarine

environment. If an estuary is excessively

turbid over long periods, its health and

productivity can be greatly diminished. 

As discussed in Chapter 9, dissolved

oxygen is a critical factor controlling

biological activity. Highly turbid water can

influence the amount of dissolved oxygen in

three ways. First, turbid waters interfere with

light penetration in the water, thereby

reducing the amount of light reaching the

bottom, making it less suitable for plant

growth. Because there are fewer aquatic

plants—and therefore less photosynthesis

taking place—less dissolved oxygen is

produced. Dissolved oxygen concentrations

are also influenced by high turbidity and its

relationship to water temperature. Suspended

particles absorb heat, which causes water

temperature to increase. Because warm water

holds less dissolved oxygen than cold water,

Why Measure Turbidity and Total Solids?

Land use decisions throughout an

estuary’s watershed impact water

quality. Here, extensive erosion

near a highway adds to the

sediment entering a nearby

estuary (photo by R. Ohrel).
15-3

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 15: Turbidity and Total Solids

It should be remembered that turbidity is not

a measurement of the amount of suspended

solids present or the rate of sedimentation of an

estuary—it measures only the amount of light

that is scattered or absorbed by suspended particles. Some laboratories also measure “total

solids” in a waterbody, which is related to turbidity. Measurement of total solids is a more

direct measure of the amount of material suspended and dissolved in water.

Chapter 6 summarized several factors that

should be considered when determining monitoring sites, where to monitor, and when to

monitor. In addition to the considerations in

Chapter 6, a few additional ones specific to

monitoring turbidity are presented here.

When to Sample 

In setting up a turbidity monitoring plan, the

program manager should ensure that the effort

will continue for several years. Since the workings of an estuary are complex, a mere year or

two of turbidity data is insufficient to capture

the variability of the system. In fact, a few

years of unusual data may be quite misleading

and tell a story very different than reality. On

the other hand, volunteers can detect some

sources of erosion and turbidity in just one or

two monitoring sessions.

Volunteers should sample water for turbidity

on a weekly or biweekly basis, year-round. The

key to effective turbidity monitoring is to 

sample at a sufficiently frequent interval and 

this temperature increase causes a reduction in

dissolved oxygen concentrations. High

turbidity may also be caused by high levels of

dead organic matter, called detritus. Detritus

can include leaves, twigs and other plant and

animal wastes. As these materials are

decomposed by bacteria, oxygen can be

depleted. 

Some of the physical effects of excessive

suspended materials include:

• clogged fish gills that inhibit the

exchange of oxygen and carbon dioxide;

• reduced resistance to disease in fish;

• reduced growth rates;

• altered egg and larval development;

• fouled filter-feeding systems of animals;

and

• hindered ability of aquatic predators

from spotting and tracking down 

their prey.

Suspended materials such as sand, soil, or

silt tend to settle out faster in brackish water

than in fresh water. These particles settle to

the estuary bottom, where they smother fish

eggs and bottom-dwelling animals, and alter

the habitat needed by estuary plants and

animals. For example, oysters require a hard

surface on which to attach and grow. Increased sedimentation in an estuary can cover the

available hard surfaces such as rocks and

older oyster beds, leaving oysters without the

habitat that is critical to their survival.

Another problem with sedimentation in an

estuary is that the newly settled particles may

not be the same size as the estuary’s natural

bottom sediment, causing shifts from fine to

coarser sediments (or vice versa). This change

in sediment size can greatly affect the plants

and animals that have adapted to the estuary’s

benthic environment.

Higher concentrations of suspended solids

can serve as carriers of toxins, which readily

cling to suspended particles. This is

particularly a concern where pesticides are

being used on irrigated crops. Where solids

are high, pesticide concentrations may

increase well beyond those of the original

application as the irrigation water travels

down irrigation ditches and ultimately into

estuaries. ■

Sampling Considerations
15-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 15: Turbidity and Total Solids Unit Two: Physical Measures

at enough representative sites so that the

data will account for most of the inherent

variability within the system.

Since turbidity often increases sharply

during and immediately following a rainfall, volunteers may be asked to take

additional turbidity readings shortly after

the storm (as soon as it is safe to do so).

Stormwater, as it enters an estuary, often

creates a plume of highly turbid water.

This is because the stormwater is carrying high levels of suspended solids due

to erosion as well as sediment from roads and

parking lots in the watershed. The extent of the

plume can usually be seen from above, as the

color of water in the plume is different from the

water in the estuary’s main body. Some volunteer monitoring programs include “stormwater

plume tracking” as part of their turbidity data

collection to assess the spatial extent of

stormwater discharges (see box, this page).

Where to Sample

If the monitoring program is designed to pinpoint trouble spots in the estuary, the manager

should select monitoring sites throughout the

estuary, as well as cluster sites near suspected

sources of turbid water into the estuary. Such

sites might include an area near a discharge

pipe or a river that flows into the estuary. Since

rivers may have multiple trouble spots, your

monitoring efforts may require several monitoring sites in the rivers and tributaries. 

Choosing a Sampling Method

When deciding upon the appropriate method

for measuring turbidity levels in an estuary, the

program manager must consider the cost of

equipment, the number and location of sites to

be monitored by volunteers, and the planned

uses for the collected data. 

There are four commonly used methods to

measure turbidity in estuary waters. Turbidity

meters measure turbidity, while the Secchi disk,

transparency tube, and turbidity field kits measure transparency, which is an integrated measure of light scattering and absorption. Samples

can also be collected by volunteers and sent to a

lab for analysis. Monitors interested in submitting data to water quality agencies should consult with the agencies to determine the preferred

equipment and methods.

Secchi Disk

Most volunteer water quality monitoring programs rely on the Secchi disk because it is easy

to use, inexpensive, and relatively accurate. It is

also easy to make (see box, page 15-5). The

Secchi disk was invented by the Italian

astronomer Pietro Angelo Secchi in the 1860s.

This simple weighted disk is used by volunteers

to measure the water depth at which the disk

just disappears from view—the Secchi depth.

Most programs find that the Secchi disk gives

sufficiently good clarity readings. 

The Secchi disk is 20 centimeters (8 inches)

in diameter and divided into alternating black

and white quadrants to enhance visibility and

contrast (although some disks are totally white).

Secchi disks cost about $25 to $50 and can be

homemade.

It is lowered by hand into the water to the

depth at which it vanishes from sight. The distance to vanishing is then recorded, and then

the procedure is repeated so that two readings

Stormwater Plume Tracking

As part of a turbidity monitoring program, volunteers can conduct

“plume tracking” to assess the spatial extent of stormwater discharges.

By monitoring for runoff characteristics (i.e., high turbidity, low

salinity, etc.) near the mouth of a freshwater input to the estuary,

volunteers can assess how far the stormwater plume emanating from

the stream or river extends into the estuary. 

An effective method to monitor a stormwater plume is to divide the

plume area into a grid, and conduct sampling in each of the grid areas.

Sampling should extend from the area of greatest freshwater impact,

across the plume, and beyond the edge of the plume. Studying the fate

of stormwater and its effects on an estuary is an important component

to understanding the amount of material flowing into the estuary and

where stormwater material is deposited. With this monitoring, we can

begin to learn what residual effects the deposited material has on the

natural function of the estuary’s ecosystem. By regularly monitoring

storm plumes, volunteers can collect valuable information that can help

detect trends.

As stormwater enters

an estuary, it often

creates a plume of

highly turbid water. In

this photo, a plume of

stormwater delivers

large amounts of

dissolved and suspended materials to an

estuary (photo by G.

Carver).
15-5

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 15: Turbidity and Total Solids

are obtained. The clearer the water, the greater

the distance. If you are monitoring tributaries to

the estuary, you may find a Secchi disk of limited use, however, because in many cases the

river bottom will be visible and the disk will

not reach a vanishing point. 

Secchi readings will vary with the specific

estuary, location in the estuary, and season.

Water clouded with sediment after a storm or

with high levels of phytoplankton during a

warm spell will have low Secchi readings (poor

water clarity). Low productivity winter waters

or estuarine water located near the ocean will

generally register higher Secchi depths. A significant change in Secchi depth may motivate a

monitoring program to identify possible causes.

WARNING! 

Beware of Secchi Line Shrinkage

Over time, a Secchi disk line may begin to

shrink from regular water exposure and

subsequent drying. This can lead to errors

in Secchi depth measurements.

To minimize this problem, use a minimalstretch nylon cord, a vinyl-coated braided

metal-core clothesline, or other shrinkresistant line. But no matter what material you

use, it is critical to calibrate Secchi disk lines

regularly (e.g., every six months).

A Secchi disk is one of the simpler pieces of equipment required

for water quality testing. Although many supply companies sell

this item, volunteer programs on a tight budget can construct their

own disks (Figure 15-1). Materials needed for this project are: 

• 1/8” thick steel, 1/4” Plexiglas, or 1/4” to 1/2” marine

plywood 

• drill with 3/8” inch bit 

• shrink-resistant rope or cord (e.g., minimal-stretch nylon,

vinyl-coated braided metal-core clothesline)

• eyebolt (5/16”), approximately 3” to 4” long

• flat washers, lock washers, 2 nuts (5/16”)—2 of each

• attachable weights 

• meter stick 

• black and white flat enamel paint 

• paintbrush

• marking pen 

Cut the steel, Plexiglas, or plywood into a circle with a 20-centimeter (8”) diameter. Section the disk into four quarters

and paint two opposing quarters white and the other two black. Paint the other side of the disk totally white. 

After the paint has dried, drill a hole in the center of the disk. Put a nut onto the eyebolt followed by a lock washer and

flat washer. Insert the eyebolt assembly through the hole in the disk with the white and black side facing the eye of the

bolt. Place another flat washer on top of the assembly along with a sufficient number of weights (dependent on the disk

material used). Add another lock washer and nut to finish the assembly. 

Attach a 6-meter length of shrink-free cord or rope through the eyebolt and fasten securely. Place the meter stick

alongside the rope and disk and mark the rope in 5- or 10-centimeter increments with an indelible marker or waterproof

ink measuring from the top of the disk. A different color marker used at each full meter increment will facilitate reading

Secchi measurements.

MAKING A SECCHI DISK 

Figure 15-1. A homemade Secchi disk.

Attach incremented rope here

Eye Bolt

Lock Washer

Flat Washer Nut

Black & White

Secchi Disk

Weight

Nut

Flat Washer

Lock Washer
15-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 15: Turbidity and Total Solids Unit Two: Physical Measures

Turbidity Meter

The most accurate means of

assessing turbidity is with a turbidity

meter, called a nephelometer. A

turbidity meter consists of a light

source that illuminates a water sample

and a photoelectric cell that measures

the intensity of light scattered at a 90°

angle by the particles in the sample. It

measures turbidity in nephelometric

turbidity units or NTUs. Meters can

measure turbidity over a wide range,

from 0 to 1,000 NTUs. Measurements

can jump into hundreds of NTUs during runoff events. Therefore, the

turbidity meter to be used should be

reliable over the range in which you

will be working. Meters of this quality

cost about $800. Many meters in this

price range are designed for field or lab use. 

Although turbidity meters can be used in

the field, volunteers might want to collect

samples and take them to a central point for

turbidity measurements. This is because of the

expense of the meter (most programs can

afford only one and would have to pass it

along from site to site, complicating logistics

and increasing the risk of damage to the

meter) and because the meter includes glass

cells that must remain optically clear and free

of scratches. At a reasonable cost, volunteers

can also take turbidity samples to a lab for

meter analysis. 

Transparency Tube

The transparency tube (sometimes called a

“turbidity tube”) is a clear, narrow plastic tube

marked in units (usually centimeters) with a

light and dark pattern painted on the bottom.

Water is poured into the tube until the pattern

disappears. Volunteers then record the depth

at which the pattern disappeared. Volunteer

groups using transparency tubes have found

tube readings to relate fairly well to lab

measurements of turbidity and total suspended

solids, although the transparency tube is not

as precise or accurate as a meter. Also,

readings in transparency tubes can be

rendered inaccurate in cases of highly colored

waters. A transparency reading taken from

one tube cannot be compared with a reading

taken from another tube of a different

manufacturer, especially if the tube is

homemade. Transparency tubes can be

purchased from scientific supply houses for

about $35 to $60.

Turbidity Field Kits

With these kits, turbidity is measured by

using a standardized turbidity reagent to

match the turbidity of a water sample. Drops

of the turbidity reagent are added to a test

tube of turbidity-free water until the water in

the test tube becomes as blurred or cloudy as

the water sample from the estuary, which is in

an identical test tube. These field kits cost

about $40. 

Laboratory Analysis

Analysis of turbidity or of total solids by a

professional laboratory is by far the most

accurate means of obtaining this data. Most

laboratories institute strict quality assurance

and quality control methods to ensure

consistently reliable results. A college or

professional lab may offer its services free of

charge to a volunteer program. 

If the program decides to use lab analysis, it

must ensure that its volunteers adhere to strict

guidelines while collecting samples. Sloppy

field collection techniques will result in 

poor data. ■

A volunteer uses a

Secchi disk from the

shady side of a dock

(photo by K. Register).
15-7

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 15: Turbidity and Total Solids

General procedures for measuring turbidity

are presented in this section for guidance

only; they do not apply to all sampling

methods. Monitors should consult with the

instructions that come with their sampling

and analyzing instruments. Those who are

interested in submitting data to water

quality agencies should also consult with

the agencies to determine acceptable

equipment, methods, quality control

measures, and data quality objectives (see

Chapter 5).

Reminder!

To ensure consistently high quality data,

appropriate quality control measures are

necessary. See “Quality Control and

Assessment” in Chapter 5 for details.

Before proceeding to the monitoring site

and collecting samples, volunteers should

review the topics addressed in Chapter 7. It is

critical to confirm the monitoring site, date,

and time; have the necessary monitoring

equipment and personal gear; and understand

all safety considerations. Once at the

monitoring site, volunteers should record

general site observations, as discussed in

Chapter 7.

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site for each sampling session:

• turbidity meter, turbidity standards, lintfree cloth to wipe the cells of the meter;

or

• Secchi disk with weight attached and on a

calibrated line; or

• transparency tube; or 

• turbidity test kit.

STEP 2: Monitor turbidity.

The following section describes

four ways to analyze a water

sample for turbidity. If analyzing

turbidity by Secchi disk, follow

Procedure A. If using a turbidity

meter, use Procedure B. If using a

transparency tube, follow Procedure

C. If using a turbidity field test kit,

follow Procedure D.

Procedure A—Measuring water

clarity with a Secchi disk 

The key to consistent results is to

train volunteers to follow standard

sampling procedures and, if possible,

have the same individual take the

reading at the same site throughout

the season. If the conditions vary 

from this ideal situation, record any

differences on the data sheet. The line

attached to the Secchi disk must be

marked according to units designated by the

volunteer program. Many programs require

volunteers to measure to the nearest 1/10 meter.

Meter intervals can be marked with waterproof

ink or tagged (e.g., with duct tape) for ease of

use. Do not wear sunglasses while viewing the

Secchi disk in the water. 

The optimal conditions for recording Secchi

disk readings are: 

• clear sky;

• sun directly overhead (but disk should

be in shade or shadow); and

• measurements made from the protected

side of a boat or dock with minimal

waves or ripples.

Steps for using a Secchi disk are as follows: 

• Check to make sure that the Secchi disk

is securely attached to the measured line. 

• Tie a wrist loop at the end of the rope so

that the rope end does not accidentally

drop into the water when the disk is

lowered.

How to Measure Turbidity

Using a transparency tube is an easy

way to measure the water transparency. It is especially useful in water

that is too shallow for a Secchi disk

(photo by K. Register).
15-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 15: Turbidity and Total Solids Unit Two: Physical Measures

• Lean over the shady side of the boat or

dock and lower the Secchi disk by hand

into the water, keeping your back

toward the sun to block glare. Make

sure the disk hangs horizontally when

suspended.

• Lower the disk until it disappears from

view. Lower it one third of a meter and

then slowly raise the disk until it just

reappears. Move the disk up and down

until the exact vanishing point is found.

This is called the limit of visibility.

• Attach a clothespin to the line at the

point where the line enters the water or,

if that is not possible, note carefully

where the line meets the water’s surface

(Figure 15-2). Raise the Secchi disk and

record the depth measurement on your

data sheet.

• Repeat the procedure and write the

second measurement on your data sheet,

as well as the average of the two depths.

• If the disk hits the bottom before

dropping out of sight, note this

observation and record the 

bottom depth.

Procedure B—Measuring water turbidity with a

turbidity meter

• Prepare the sample containers.

If factory-sealed, disposable Whirl-pak

bags are used to sample, no preparation

is needed. Reused sample containers

(and all glassware used in this procedure)

must be cleaned before the first run and

after each sampling run. Follow the

procedures described in Chapter 7.

• Collect the sample.

Refer to Chapter 7 for details on how to

collect water samples using screw-cap

bottles or Whirl-pak bags. 

• Analyze the sample.

While monitors should consult with 

the instructions that come with their

turbidity meter, the following procedure

applies to field or lab use of most

turbidity meters:

(a) Prepare the turbidity meter for use

according to the manufacturer’s

instructions.

(b) Use the turbidity standards provided

with the meter to calibrate it. Make

sure it is reading accurately in the

range in which you will be working. 

(c) Shake the sample vigorously and

wait until the bubbles have

disappeared. You might want to tap

the sides of the bottle gently to

accelerate the process. 

(d) Use a lint-free cloth to wipe the

outside of the tube into which the

sample will be poured. Be sure not to

handle the tube below the line where

the light will pass when the tube is

placed in the meter. NOTE: If the

tube becomes scratched, it will have

to be replaced. The scratches on the

glass can affect the meter’s readings.

(e) Pour the sample water into the tube.

Wipe off any drops on the outside of

the tube. 

(f) Set the meter for the appropriate

turbidity range. Place the tube in the

meter and read the turbidity

measurement directly from the 

meter display. 

(g) Record the result on the field or 

lab sheet. 

(h) Repeat steps c-g for each sample. 

Procedure C—Measuring water clarity with a

transparency tube

Readings in transparency tubes can be

rendered inaccurate in cases of highly colored

waters. A transparency reading taken from one

tube cannot be compared with a reading taken

from another tube of a different manufacturer,

especially if the tube is homemade. 

• Collect the sample in a bottle or bucket

at mid-depth if possible. Avoid stagnant

Clothespin Meters

Meters

Meter

Marked in

tenth of

a meter

increments

3

2

1

Figure 15-2. Using a

Secchi disk to measure

transparency. The disk

is lowered until it is no

longer visible. That

point is the Secchi disk

depth (redrawn from

USEPA, 1997).
15-9

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 15: Turbidity and Total Solids

water and sample as far from the

shoreline as is safe. Avoid collecting

sediment from the bottom.

• Prepare the transparency tube by placing

it on a white surface.

• Look vertically down the tube to see the

black and white pattern on the bottom.

Take readings in open but shaded

conditions. Avoid direct sunlight by

turning your back to the sun. 

• Stir or swish the water in the bucket or

bottle until it is homogeneous, taking

care not to produce air bubbles (these

will scatter light and affect the

measurement).

• Slowly pour the water sample into the

tube, stopping intermittently to see if the

black and white pattern has disappeared.

To avoid introducing air bubbles, pour

the water against the inside wall of the

tube.

• When you can no longer see the pattern,

look at the ruler on the side of the tube,

and record the number of units on your

data sheet. This is the depth of the water

column in the tube when the pattern just

disappears.

NOTE: Some transparency tubes have a

water-release valve at the bottom of the tube.

With these tubes, you are required to fill the

tube entirely, then open the valve while you

look down the tube. As soon as you see the

black and white pattern appear, close the

valve, and record the depth at which you first

saw the pattern. 

Procedure D—Measuring water clarity with a

turbidity field kit

While monitors should consult with the

instructions that come with their kits, the

following procedure applies to most turbidity

field kits:

• The kits come with two tubes, each with

a black and white pattern on the bottom.

Fill one of the two turbidity tubes to the

line indicated with the water to be

tested. This is usually 50 ml. If you

cannot see the black and white pattern

on the bottom of the tube when you

look down through the column, pour out

half of the water until 25 ml remains in

the test tube (or pour out the amount

stated in your kit’s instructions).

• Fill the second turbidity tube with

turbidity-free water that is equal to the

amount of the sample (50 or 25 ml).

Distilled or tap water can be used.

• Place the tubes next to each other, and

look down the tubes to note the

difference in clarity. If there is a

difference in clarity, go on to the 

next step.

• Shake the bottle of standard turbidity

reagent, and add the reagent to the

“clear water” tube according to the kit’s

instructions. Keep track of how much

reagent is being added. Stir the contents

of both tubes to equally distribute turbid

particles. After each addition of reagent,

compare the turbidity of the tubes.

• Continue to add the reagent and stir

both tubes until the turbidity of both test

tubes is the same. 

• Record the total amount of turbidity

reagent added.

STEP 3: Clean up and send off data.

Volunteers should thoroughly clean all

equipment and transport the samples to the

designated lab, if necessary. Samples submitted to a lab for analysis must be processed

within 24 hours of collection. Keep samples

in the dark and on ice or refrigerated.

Make sure that the data sheet is complete,

legible, and accurate, and that it accounts for

all samples. Volunteers should make a copy of

the completed data sheet before sending it to

the designated person or agency in case the

original data sheet becomes lost.
15-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 15: Turbidity and Total Solids Unit Two: Physical Measures

The measurement of total solids cannot be

done in the field. Samples must be collected

using clean glass, plastic bottles, or Whirl-pak

bags and taken to a laboratory where the test

can be run. Total solids are measured by

weighing the amount of solids present in a

known volume of sample. This is done by

weighing an empty beaker, filling it with a

known volume, evaporating the water in an

oven and completely drying the residue, and

then weighing the beaker with the residue.

The total solids concentration is equal to the

difference between the weight of the beaker

with the residue and the weight of the beaker

without it. 

Total solids are measured in milligrams per

liter (mg/l). Since the residue is so light in

weight, the lab will need a balance that is

sensitive to weights in the range of 0.0001

gram. Balances of this type are called

analytical or Mettler balances, and they are

expensive (around $3,000). The technique

requires that the beakers be kept in a

desiccator, which is a sealed glass vessel

containing material that absorbs moisture and

ensures that the weighing is not biased by

water condensing on the beaker. Some

desiccants change color to indicate moisture

content. 

Volunteers can collect samples for total

solids analysis using the instructions in

Chapter 7. If you are sending your samples to

a lab for analysis, they must be tested within

24 hours of collection. Keep samples in the

dark and on ice or refrigerated. Learn from

the lab what volume of water needs to be

collected. For some tests, 50 ml are needed,

while other tests require 100 ml or more. ■

How to Measure Total Solids

References and Further Reading

Portions of this chapter were excerpted and adapted from:

National Estuary Program (NEP). Web site: http://www.epa.gov/owow/estuaries/about1.htm

Southern California Coastal Water Research Project, 1999/2000 Research Plan, Westminster, CA.

Web site: http://www.sccwrp.org

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A Methods

Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

Other references:

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L. S. Clesceri, A. E. Greenberg, A. D. Eaton (eds). Washington, DC.

Association of National Estuary Programs(ANEP). 1998. Preserving Our Heritage, Securing Our

Future: A Report to the Citizensof the Nation. Washington, DC. 49 pp.
15-11

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 15: Turbidity and Total Solids

Baldwin County (Alabama) Soil and Water Conservation District. 1993. Unpublished report on

agricultural field runoff and erosion in the Weeks Bay watershed.

Mitchell, M., and W. Stapp. 1999. Field Manual for Water Quality Monitoring.12th ed. Kendall/

Hunt. Available from GREEN, c/o Earth Force, Inc., 1908 Mount Vernon Ave., Alexandria, VA

22301; phone: 703-299-9400; catalog # ISBN-1-6801; 

Web site: http://www.earthforce.org/green/

National Safety Council’s Environmental Center. 1998. Coastal Challenges: A Guide to Coastal and

Marine Issues. Prepared in conjunction with Coastal America. 

Web site: http://www.nsc.org/ehc/guidebks/coasttoc.htm.

U.S. Environmental Protection Agency (USEPA). 1991. Volunteer Lake Monitoring: A Methods

Manual. EPA 440/4-91-002. Office of Water, Washington, DC. 

White, T. 1994. “Monitoring a Watershed: Nationwide Turbidity Testing in Australia.” The

Volunteer Monitor 6(2): 22-23.

Web sites:

National Estuary Program (NEP): http://www.epa.gov/owow/estuaries/about1.htm

Environmental Protection Agency’s Office of Wetlands, Oceans, & Watersheds:

http://www.epa.gov/owow/monitoring/volunteer/stream/

http://www.epa.gov/owow/monitoring/index.html

U.S. Geological Survey, Florida Bay: http://coastal.er.usgs.gov/flbay/ref.html
15-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 15: Turbidity and Total Solids Unit Two: Physical Measures
Chapter16 Marine Debris

Waterbodies have historically been dumping grounds for human-made debris. Rarely

can a person visit a stream, lake, river, estuary, or ocean and fail to observe some

form of trash. This debris originates from many activities, but is generally

categorized as coming from land-based or ocean/inland waterway-based sources.

Regardless of its origin, however, marine debris impacts human health and safety;

poses an entanglement or ingestion threat to wildlife; and degrades critical habitats.
All photos by The Ocean Conservancy
16-1

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 16: Marine Debris

Waterbodies have historically been dumping grounds for human-made debris.

Rarely can a person visit a stream, lake, river, estuary, or ocean and fail to observe

some form of trash. This debris originates from many activities, but is generally

categorized as coming from land- or ocean/inland waterway-based sources.

Regardless of its origin, however, marine debris impacts human health and safety;

poses an entanglement or ingestion threat to wildlife; and degrades critical habitats.

Volunteer groups may be attracted to marine debris monitoring because of the

pervasiveness of the problem and the ease with which marine debris pollution can

be observed. They may also choose several approaches to dealing with it. Some

organizations simply remove trash from shorelines and waterways. Others take it

one step further, collecting information about the types and amounts of debris

found. This kind of data collection may be done with different levels of scientific

rigor, depending largely on the goals of the volunteer effort. 

This chapter discusses techniques for organizing a debris monitoring and cleanup

program, with emphasis on data collection and data uses.

Overview
16-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter Chapter 16: Marine Debris Marine Debris Unit Two: Physical Measures

Once, our nation’s beaches

were littered only with the

likes of dry seaweed strands,

shells, plant stems, and stranded jellyfish. These days, the litter is more likely to include

cigarette butts, grocery bags,

scraps of fishing nets, pieces of

foamed coffee cups, fast food

containers, and beverage cans

or bottles. As the coastal population has risen and society has

turned from degradable natural

materials to synthetic ones, the trash problem

has worsened. 

Of all the human-made goods produced

over the past several decades, plastics are

among the most persistent and pervasive. The

qualities that make plastic such a versatile

material for so many products can make it

harmful once it is released to the environment. Constructed to be light and durable,

plastics break down very slowly—some products even persisting for centuries.

Marine debris monitoring information from

volunteer organizations is important in many

ways. Data from monitoring efforts can be

used to:

• assess debris sources; 

• identify areas where public education and

outreach are necessary; and

• evaluate the success of legislation enacted

against littering and ocean dumping.

Marine debris monitoring and coastal

cleanups serve three major functions. First, they

reduce the amount of litter on shorelines in an

immediate and visible way—an aspect most

gratifying to the volunteers. Second, with careful planning, volunteers can document the

types, quantities, and possible sources of debris.

Third, the cleanup teaches the public about the

problems of marine debris and how citizens can

help. The sight of a littered beach transformed

into a clean one makes an impression that the

community will long remember and gives the

volunteers a strong sense of pride in their

accomplishment. Grassroots educational efforts

accompanying the cleanup can help prevent

future littering. 

Marine Debris Sources

As our knowledge about marine debris has

increased, two pathways have been shown to

contribute to the problem. These sources can be

divided into land-based and ocean/inland waterway-based. Land-based debris consists of waste

products that have washed or blown into the

water from the land. Primary sources of landbased debris include: 

• sewers; 

• combined sewer overflows;

• illegal dumping; 

• beachgoers who leave litter on beaches; 

• balloon releases;

• disposal of industrial waste products; and

• loss from coastal solid waste management

landfills via wind. 

Ocean/inland waterway-based debris items

are accidentally or deliberately discharged at

sea. Sources include:

• commercial fishing boats;

• recreational vessels;

• floating fish processing plants;

• cargo ships;

• passenger day boats and ferries;

• offshore oil platforms, rigs, and supply

boats;

• military vessels;

• passenger cruise ships; and 

• research vessels.

For many debris items, however, it is not so

easy to identify their source—whether land or

ocean/inland waterway-based.

Why Monitor Marine Debris?

Marine debris is typically comprised of

plastic, glass, rubber, metal, paper, wood,

and cloth (photo by The Ocean

Conservancy).
16-3

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 16: Chapter 16: Marine Debris

Plastic Debris

Annex V of the International Convention

for the Prevention of Pollution from Ships,

commonly known as MARPOL, bans the

disposal of plastic into the world’s oceans

and establishes limits on the disposal of

other garbage. Many countries, including

the United States, have agreed to this

treaty. Over time, this agreement should

substantially reduce the load of plastics

entering the marine environment. The

United States also prohibits the disposal of

plastic into the nation’s navigable waterways from any vessel—ranging from the

largest tanker to an inner tube. 

The Role of Marine Debris in the Estuarine

Ecosystem

A walk along any but the most pristine

coastal or estuarine shoreline will quickly

reveal an astonishing array of human-made

products. Beaches are natural accumulation

areas for ocean- and land-based debris.

Nearshore waves tend to push marine litter

landward where it becomes stranded as high

tide recedes. Beaches are also popular

recreation areas and users often leave their

trash behind.

The many marine debris sources make it

one of the more widespread pollution

problems threatening estuarine and coastal

systems. The problem of today’s litter is not

merely aesthetic. Once litter gets into the

estuarine environment, it seriously affects

humans, wildlife, and habitats. 

Human Impacts

Plastic debris (e.g., nets, fishing lines, trash

bags) can snare boat propellers or clog

cooling water intakes, causing substantial

damage to the motor. A disabled motor can

not only be costly to fix, but can leave boaters

stranded in the water—a potentially

dangerous situation. 

Debris can also affect

human health. Medical

wastes menace barefoot

beachgoers and pose a

threat of contamination.

Glass or metal shards can

cause serious injuries. 

Some beaches with

marine debris problems

face the possibility of

losing money. Without

regular beach cleaning—an

expensive undertaking—

many coastal communities

risk losing tourism

revenues. 

Wildlife Impacts

Wildlife often fare even

worse than humans. Marine debris can

mean death to estuarine animals. One

common cause of death by marine

debris is entanglement. Many animals

can become caught in discarded

fishing nets and lines, rope, six-pack

rings, balloon ribbons, grocery bags,

and other floating debris.

Some animals die from marine

debris ingestion, mistakenly eating

the human-made materials. Endangered sea turtles, for example,

consume floating trash bags and

balloons, likely mistaking them for

jellyfish—a staple in most sea

turtles’ diets. Several seabird species

have been found to swallow plastic

pieces and cigarette butts. These

materials can damage the animals’ digestive

systems. Alternatively, animals may stop

eating because their stomachs are full.

Because the debris in their stomachs offers no

nutritional value, the unfortunate creatures

may eventually starve to death.

At least 267 marine species are known to

have either become entangled in or ingested

marine debris (Faris and Hart, 1995; MMC,

1997). 

Wildlife entanglement is

just one of the impacts of

marine debris. Animals

caught in debris may

eventually die (photos by

The Ocean Conservancy). 
16-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 16: Marine Debris Unit Two: Physical Measures

Habitat Impacts

Marine debris can cause problems for the

estuary system. Debris coming from miles

away may carry with it opportunistic plants

and animals that colonize the debris’ surface.

These non-indigenous species can have

devastating impacts for the region (see

Chapter 19). Submerged debris can also cover

communities such as coral reefs and smother

seagrasses and bottom-dwelling species.

Levels of Marine Debris

Marine debris is pervasive throughout

coastal regions. Similar to most estuarine

pollution parameters, the amount of marine

debris at any single moment can depend on

the estuary location, its surrounding land use,

the frequency of cleaning by municipal

agencies, and environmental conditions,

among other factors. 

Each year, on the third Saturday in

September, The Ocean Conservancy conducts

the International Coastal Cleanup. During this

activity, volunteers remove debris from

shorelines and underwater sites. The volunteers

also collect information about the items found.

The Ocean Conservancy uses the volunteer data

to evaluate the success of anti-litter and antidumping legislation. The data are also used to

identify debris sources and public outreach

possibilities.

The Ocean Conservancy compiles the

information collected during the International

Coastal Cleanup and generates a list of the

most frequently found debris items (Table 16-

1). The list provides insight to where litter

prevention efforts can be concentrated. ■

Debris Items Total Number Reported Percentage of Total Collected

1. cigarette butts 1,027,303 20.25%

2. plastic pieces 337,384 6.65%

3. food bags/wrappers (plastic) 284,287 5.60%

4. foamed plastic pieces 268,945 5.30%

5. caps, lids (plastic) 255,253 5.03%

6. paper pieces 219,256 4.32%

7. glass pieces 209,531 4.13%

8. beverage cans 184,294 3.63%

9. beverage bottles (glass) 177,039 3.49%

10. straws 161,639 3.19%

11. beverage bottles (plastic) 150,129 2.96%

12. bottle caps (metal) 130,401 2.57%

Top 12 Totals 3,405,461 67.12%

Table 16-1. Most frequently found marine debris items in the United States. Data represent shoreline and

underwater cleanups during the 2000 International Coastal Cleanup (The Ocean Conservancy Web site).
16-5

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 16: Marine Debris

Marine debris cleanup programs generally

fall into two categories:

• programs that collect and remove

debris; and

• programs that collect and remove

debris, and record information on the

numbers and types of debris found.

Any organization or individual can

participate in programs that collect and

remove debris from beaches and shorelines.

This type of activity is designed to clean the

area and raise general public awareness of

marine debris pollution. Such programs can

elicit a sense of pride and accomplishment in

their volunteers and in the

community.

Other cleanup programs

go beyond simply

collecting and removing

debris. Some programs,

such as The Ocean

Conservancy’s

International Coastal

Cleanup and National

Marine Debris Monitoring

Program, record data on

the numbers and types of

debris being found. Data collected from

cleanups can be extremely important in

Sampling Considerations and Options

Case Study: National Marine Debris Monitoring Program

Supported by the U.S. Environmental Protection Agency (USEPA), The Ocean Conservancy

coordinates the National Marine Debris Monitoring Program (NMDMP). NMDMP is a

scientifically valid marine debris study utilizing volunteer groups to monitor and remove

marine debris on U.S. coastal beaches. Trained volunteers conduct beach debris surveys

following a strict scientific protocol and procedures. 

The NMDMP was started in the spring of 1996. The goal is to establish and maintain 180

marine debris monitoring sites along the entire coastal United States, including Alaska,

Hawaii, Puerto Rico, and the U.S. Virgin Islands. Monitoring sites are surveyed monthly by

hundreds of volunteers.

The NMDMP is a five-year program designed to scientifically answer two fundamental

questions regarding marine debris: 

• Is the amount of debris on our coastlines decreasing? 

• What are the major sources of the debris? 

Information gathered by the NMDMP study will be utilized by the USEPA, National Marine

Fisheries Service, National Park Service and the U.S. Coast Guard to better understand the

problem of marine debris pollution.

The NMDMP data card can be found in Appendix A.

For More Information:

The Ocean Conservancy

Office of Pollution Prevention and Monitoring

1432 N. Great Neck Road, Suite 103

Virginia Beach, VA 23454

Phone: 757-496-0920

Fax: 757-496-3207

http://www.oceanconservancy.org

Email: nmdmp@oceanconservancyva.org

International Coastal Cleanup volunteers in

Puerto Rico (photo by S. Sheavly, The Ocean

Conservancy).
16-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 16: Marine Debris Unit Two: Physical Measures

convincing politicians to

actively solve the marine

waste problem and are

useful at all levels of

government. The use of a

data card (Appendix A)

facilitates the collection

of marine debris

information during the

cleanup activity.

Any marine debris

cleanup program conducted by a volunteer

group should be thoroughly planned and

thought out. The following basic questions

should be considered before proceeding with

the activity:

• Why do we want to conduct a cleanup?

What do we want to accomplish?

• Do we just want to conduct a cleanup

simply to remove debris, or do we want

to collect some kind of data?

• If we want to collect data, how will the

data be used? What do we hope to

accomplish with the data (e.g., influence

legislation, monitor debris type or

accumulation trends, identify debris

sources, etc.)?

• What kind of data do we want to

collect? (The type of data should be

determined by what it is you want to

accomplish.)

• Will this be a one-day event, or will it

need to be repeated periodically?

(Collecting meaningful data on debris

may take repeated efforts.)

Choosing a Sampling Method

Marine debris monitoring is a very simple

process. The sampling method selected will

depend largely on the goals of the volunteer

program. Sampling methods used as part of

the International Coastal Cleanup and the

National Marine Debris Monitoring Program

(NMDMP) are briefly summarized here. Only

the NMDMP method follows a scientifically

valid and rigorous sampling protocol.

Method Used for International Coastal Cleanup

Volunteers fan out over a monitoring site

(e.g., by foot on land, by boat, or by swimming), randomly searching for debris. Using

data cards, they identify and quantify the debris

items. The entire event provides a one-day

“snapshot” of the types and quantities of debris

occurring along shorelines and in waterways.

No scientific protocol is followed during this

activity.

The International Coastal Cleanup is very

useful for heightening public awareness about

marine debris and its prevention and provides

insights into the sources and activities producing marine debris. Because it lacks scientific

rigor, however, this method may not reveal

information about marine debris trends. 

Method Used for National Marine Debris

Monitoring Program

The NMDMP is an example of a marine

debris monitoring program that follows a scientific protocol for data collection. 

Every 28 days, volunteers remove debris

from a randomly selected and pre-measured

500-meter stretch of beach. Each 500-meter

survey unit must:

• be of sandy or small gravel

composition;

• have a moderate to low slope (15-45

degrees) along the width of the beach;

• receive no other routine cleaning;

• not be protected from the ocean by

jetties, breakwaters, etc.;

• be accessible for monthly monitoring;

and

• contain at least 500 meters of accessible

length.

Not only is there scientific rigor designed

into the selection of monitoring sites, but

The National Marine Debris Monitoring

Program is conducted on stretches of beach

throughout the United States. Here, a volunteer

coordinator measures a 500-meter monitoring

site in North Carolina (photo by The Ocean

Conservancy).
16-7

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 16: Marine Debris

volunteers are also trained in the proper

methods for conducting a cleanup. Instead of

walking randomly, volunteers must walk in a

prescribed pattern (Figure 16-1) to ensure that

the entire survey area is covered. Data cards

are used to identify and quantify the debris

items. The NMDMP also incorporates a

quality assurance protocol (see Chapter 5) to

guarantee the validity of the collected data.

The NMDMP utilizes only ocean beach

sites; however, volunteer estuary monitoring

groups may consider a similar protocol design

to suit their particular data collection needs. ■

How to Conduct a Marine Debris Cleanup

2 meters

500 meters

Litter Trapping Feature

Ocean

500 meters

Figure 16-1. Specific

walking pattern for

inventorying marine

debris as part of the

National Marine Debris

Monitoring Program

(NMDMP) (from 

Center for Marine

Conservation, 1997).

Depending on the level of sophistication and

the data needs of the program, organizing a

marine debris cleanup can take minutes or

months. Although getting a few people onto the

local beach to pick up some trash may seem

like an easy task, a successful cleanup can

involve hundreds of people and demand months

of organization, recruitment, and planning.

Regardless of the program objectives, a few

general elements to a marine debris monitoring

program are presented here for the volunteer

leader. These elements are derived from The

Ocean Conservancy’s International Coastal

Cleanup and can be divided into three

categories: before the cleanup, the day of the

cleanup, and immediately after the cleanup. 

Helpful Hint

If you plan a marine debris cleanup during

the months of September and October, 

your data can be included as part of your

state’s International Coastal Cleanup 

activity. Call 1-800-262-2322 or email

cleanup@oceanconservancyva.org before

your cleanup activity for more information.

Before the Cleanup:

STEP 1: Identify debris collection sites

that are safe and accessible to volunteers. 

• Ensure that you

will have access to

the site and that

you have the

necessary

permission to be at

the site.

• Verify cleanup date

and time.

• Identify potential

volunteer check-in

site(s) that will be

clearly visible and

have parking available; for example, if

you are conducting a waterway cleanup,

it could be located next to a boat ramp

or central area of a marina. You may

want to post signs or posters directing

people to the proper location.

• If scientific data will be collected,

volunteers should be trained prior to the

activity.

Volunteers in the National Marine Debris

Monitoring Program collect and inventory

marine debris (photo by The Ocean

Conservancy).
16-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 16: Marine Debris Unit Two: Physical Measures

STEP 2: Identify site coordinators who can

manage cleanup activities at each site.

Recruit coordinators and hold a

coordinators’ meeting. This is your

opportunity to distribute materials to the

coordinators and make sure they understand

everything they have to do. They should

know the importance of collecting data,

completing data forms, keeping track of

numbers of volunteers, and working with the

media. All site coordinators should visit their

site before the cleanup, finalize where they

will set up their check-in point, where the

dumpster should be located, and where the

volunteers will be sent.

Review what to do if there is a health

emergency (Step 8) and what to do with dead,

entangled, or injured animals (Step 9).

STEP 3: Locate a waste hauler who will

donate services to the project.

• Contact a local waste collection company

in your area. Your municipal government

may help and may even waive the

entrance fees at landfills or incinerators

for the event. 

• Identify an organization or business

willing to donate trash bags.

• Plan ahead on how filled trash bags are

going to be removed: (1) Will volunteers

carry them back to the check-in point, or

some other central location, or (2) will

they leave them as they are filled, right on

the beach (above the high tide mark), to

be picked up by truck or other vehicle? If

you chose the first option, have your

volunteers start at the far end of the zone

they will be cleaning and work their way

back to the central location. This will

decrease the distance they will have to

carry full bags of debris.

STEP 4: Plan recycling options.

A) Contact recyclers in your area and

arrange with them pickup and delivery

dates and times. 

• Recycling debris should be a major

emphasis of the cleanup project. Some

localities may have recycling

coordinators in their solid waste

departments who should be able to

assist you.

• Try to remove as much other debris

from the recyclable materials as

possible—particularly organic

matter—before sending them to be

recycled. 

B) Plan ahead how you will collect the

recyclables. Either:

• Have volunteers sort as they collect,

working in groups of four or more

(make sure to have separate bags for

recyclables; using bags of different

colors may aid the sorting process); or 

• Identify a special group of volunteers

who will work during and after the

cleanup to specifically sort the

recyclables.

You can make recycling more fun by making

a contest out of it: whoever has the most

number of cans or bottles (or most bags, or by

weight) may win a small prize or get some sort

of recognition at the end of cleanup.

STEP 5: Arrange for a scale at cleanup

sites to weigh trash bags and large

individual items (e.g., tires), or be 

sure you can get a weight from your

waste hauler.

This kind of data helps to dramatize a trash

problem and is often of particular interest to the

media.

There are several ways to calculate the

weight of trash collected:

• Secure a scale similar to those used in

seafood markets and grocery stores, or

one with a hook on it for hanging bags,

and weigh each bag of trash before it is

thrown into a dumpster. This is the most

accurate way of reporting the weight.
16-9

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 16: Marine Debris

• Your waste hauler may be able to give

you the total weight of what was hauled

away (either a real weight or a good

estimate by the number of filled

dumpsters or roll-offs).

• Estimate the total weight by weighing a

random sample of 10 filled bags of trash,

calculating the average weight per bag,

and multiplying that number by the total

number of filled trash bags.

• Also estimate the weight of items which

are too large for trash bags, including

tires, large fishing nets, and building

materials.

STEP 6: Solicit volunteers and work with

the media.

A well-publicized cleanup drive can often

attract large numbers of citizen volunteers.

The following steps can help:

• Distribute posters and brochures.

• Contact local schools, civic organizations, chambers of commerce,

environmental groups, industries, and

others willing to participate in the

cleanup.

• Distribute media announcements to

local media and the groups listed above

who may have their own newsletters or

flyers.

• If you have the time, contact specific

environmental reporters (print and

TV/radio media) in your area who may

be interested in a “before and after” type

of story. Get a photographer out to shoot

pictures of a cleanup site before the

event to illustrate the trash problem, or

supply the press with some of your own.

This will help encourage participation

the day of the event.

STEP 7: Maintain a list of people who

respond and express interest in the

cleanup to get some indication of the

number of volunteers to expect at your

cleanup sites.

This may be important in case you have too

many people wanting to go to a specific site.

Others can possibly be diverted to different

sites that may need more participants.

Consider ahead of time how volunteers will

be dispersed during the cleanup to cover your

whole cleanup area. For example, some groups

mark off sections of beach every 1/8 of a mile

(or whatever distance is appropriate), and

estimate the minimum number of volunteers

that are needed for each section. Wooden stakes

work well for markers, or telephone poles

might be used if the cleanup occurs along a

road, etc. You may want to have maps of the

cleanup site available for volunteers.

Helpful Hint

One site coordinator will not be enough

when 40 or more volunteers indicate they

will be participating at a site. As a general

rule, it takes one additional “assistant

coordinator” for every 30-40 volunteers.

STEP 8: Be prepared for health

emergencies.

• Have first aid kits available at each

cleanup site or check-in location for small

emergencies like cuts and scrapes. You

and your site coordinators should also

review what you would do if there is a

major health emergency (heat exhaustion

or heatstroke, broken bone, etc.). Write

out a plan. Know how to get to the

closest hospital or other emergency

facility from your cleanup site so you can

direct emergency personnel. Some

communities may want to have rescue
16-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 16: Marine Debris Unit Two: Physical Measures

personnel standing by, particularly for

areas expecting several hundred

volunteers. Additionally, volunteers

suffering deep cuts or puncture wounds

should check with their physician on the

need for a tetanus shot.

• Try to obtain walkie-talkies, two-way

radios, or cellular phones for each site

coordinator. This is useful for staying in

touch with each other, regardless of

possible emergencies. Local cellular

phone companies may donate phones

for such events.

Helpful Hint

Consider contacting your local police

department and marine patrol to let them

know you will be having a cleanup event.

STEP 9: Make sure volunteers know what

to do with dead, entangled, or injured

animals.

• Contact your local animal/wildlife rescue

facilities to let them know that a cleanup

will be occurring, and ask them how to

properly care for and transport any

injured animals that might be found.

• Dead wildlife could simply be left; more

often than not, they died naturally and

some scavenger will probably take care

of them. 

• Entangled animals should be removed

because other animals may become

entangled with them.

• All entanglement and injury incidents

should be reported on data cards.

Consider sharing your information with

local stranding networks, which often

keep records of dead, injured, and entangled wildlife.

STEP 10: Arrange for someone to take

photos or videos of the event.

• Good video footage may be useful for

future public service announcements or

other educational purposes.

• Label clearly all photos and slides with

the photographer’s name, name and location of site, and date. 

STEP 11: Contact merchants and other

potential donors who can supply drinks,

food, raffle prizes, or whatever else you

might need.

Many merchants will jump at the chance to

be involved in a positive and non-political

event. It is good public relations, and you can

make it even better by remembering to mention

all your donors and sponsors in press releases

or conversations with the press. Donations of

this type also encourage more participation.

The Day of the Cleanup:

STEP 12: Check your equipment. 

If water quality monitoring is to be part of

your cleanup activity, make sure to bring

along all the proper equipment designated by

the program manager (see Chapter 7 for a

general list of equipment). In addition to the

standard water quality sampling equipment

and apparel listed in Chapter 7, the site coordinator should bring the following items to

the site for each cleanup: 

• plastic garbage bags to collect debris

(have at least two bags for each expected

volunteer); 

• blank data cards; 

• pencils or pens to record data; 

• clipboards; and 

• Pocket Guide to Marine Debris (The

Ocean Conservancy and USEPA, 2000).
16-11

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 16: Marine Debris

Volunteers should be told to bring:

• gloves; 

• protective shoes; 

• sunglasses; 

• sunscreen; and

• water. 

STEP 13: Set up your check-in points.

Be prepared before your volunteers start

arriving! Have a table or area that will serve as

a volunteer check-in station set up with all

materials; sign-in sheets ready for volunteers;

and signs, if necessary, to direct volunteers to

parking, the check-in point, and where they will

be cleaning (e.g., stake off sections of the site to

be cleaned). Your dumpsters and recycling bins

should be appropriately located.

You may want to display actual examples of

the items that volunteers may be less familiar

with, if you have them. This will aid with

proper data collection.

STEP 14: Coordinate volunteers at cleanup

sites.

Critical to the success of the cleanup is

emphasizing that the volunteers’ effort will

make a difference. Distribute materials and

instruct the volunteers on the following items as

they arrive at the check-in point, either

individually or in small groups:

• Have all volunteers sign in.

• Emphasize the importance of data

collection, including information about

unusual situations or observations (see

Chapter 7). The International Coastal

Cleanup data card serves as a nationwide

standard that allows data from any beach

in the United States to be compared with

any other. Standardized data make the

national database more useful and

accurate for analysis. The Ocean

Conservancy will provide these cards at

no charge to beach cleanup programs (see

end of this chapter for contact

information).

• To facilitate data

collection and

sorting out the

recyclable trash,

encourage

volunteers to work

in teams of four or

five. Each volunteer

in the team should

be given one to two

trash bags—one for

aluminum, one for

plastic bottles, and

several others for

glass. They should sort as they go. One

volunteer, designated the “data captain,”

would be responsible for recording the

items picked up by the other volunteers

on the data card (they can call out the

items as they go). This person will

quickly become familiar with the card,

making the task easier.

• The volunteers should know what sort of

debris they are likely to encounter.

Accurate debris identification will make

the database more valuable and will also

help volunteers steer clear of potentially

dangerous materials such as medical

waste or toxic waste containers. It is best

to treat unidentified containers with

caution; 55-gallon drums and munitions

should be avoided altogether. If volunteers do find suspicious materials, they

should stay well away, but note their

quantity and location and report this

information to the program leaders. The

leaders can then determine the best means

of removing any potentially hazardous

materials.

• Emphasize safety, stressing the

importance of:

– always wearing gloves; 

– picking up glass or metal shards with

care; 

– steering clear of injured animals which

may harbor disease; 

– avoiding overexposure to the sun; 

A volunteer coordinator reviews data collection

requirements for the International Coastal

Cleanup (photo by The Ocean Conservancy).
16-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 16: Marine Debris Unit Two: Physical Measures

– not lifting heavy objects without

assistance; 

– being aware of snakes and other

animals in dunes or grasses; 

– not wading across tidal inlets (currents

are often powerful and unpredictable);

and 

– reporting any injuries to the program

leader.

• Instruct volunteers on what to do if they

find dead or entangled animals (see 

Step 9). 

• Instruct the volunteers on what they are to

do with the filled bags of trash (see 

Step 3).

STEP 15: As the volunteers return, collect

all data cards.

Tell volunteers to return the cards

immediately after the cleanup. It is best to

have a labeled box at the check-in station

where the cards can be returned. Review the

cards to ensure they were properly filled out. 

STEP 16: Be sure that volunteers get their

certificates, hats, t-shirts, or any other

giveaways before leaving the site. 

Any awards that you choose to give out

(e.g., for most recyclables, most unusual item,

etc.) can be distributed at this time as well.

STEP 17: Dispose of debris.

Oversee sorting of the recyclable debris.

Make sure the waste hauler takes all the trash

away and no other materials are left behind.

Immediately After the Cleanup:

STEP 18: Compile cleanup information.

Sample information could include the total

number of people, pounds, and miles in your

cleanup, any entanglements, unusual items,

number of trash bags filled, etc. If your

cleanup is part of a larger event, send the data

cards to the event coordinator. If feasible,

make copies of the cards before sending them,

in case the originals become lost.

STEP 19: Follow up with site coordinators

and key volunteers.

This is intended to gauge the success of the

materials developed for promotion of the

cleanup, effectiveness of media coverage, etc.

They then use this information to plan for

next year’s cleanup to make it even more

efficient and effective. ■
16-13

Volunteer Estuary Monitoring: A Methods Manual

Unit Two: Physical Measures Chapter 16: Marine Debris

Portions of this chapter were excerpted and adapted from:

The Ocean Conservancy. 2002. International Coastal Cleanup (ICC) Coordinator Handbook. 

Other references:

Center for Marine Conservation (now The Ocean Conservancy). 1997. National Marine Debris

Monitoring Program Volunteer Handbook. 

Faris, J. and K. Hart. 1995. Seas of Debris: A Summary of the Third International Conference on

Marine Debris. NC Sea Grant College Program. UNC-SC-95-01.

Marine Mammal Commission (MMC). 1997. Annual Report to Congress. Bethesda, MD. 239 pp.

The Ocean Conservancy and U.S. Environmental Protection Agency (USEPA). 2001. Pocket

Guide to Marine Debris. Washington, DC. 

U.S. Environmental Protection Agency (USEPA). 1989. Marine Debris Bibliography.

Washington, DC. 25 pp.

U.S. Environmental Protection Agency (USEPA). 1992. Turning the Tide on Trash: A Learning

Guide on Marine Debris. EPA 842-B-92-003. Office of Water, Washington, DC. 78 pp.

Web sites:

The Ocean Conservancy: http://www.oceanconservancy.org

U.S. Environmental Protection Agency: http://www.epa.gov/owow/oceans/debris/index.html

For information about the International Coastal Cleanup for marine debris research:

The Ocean Conservancy

Office of Pollution Prevention and Monitoring 

Atlantic Regional Office

1432 N. Great Neck Road, Suite 103

Virginia Beach, VA 23454

Phone: 757-496-0920

Fax: 757-496-3207

Email: cleanup@oceanconservancyva.org

The newsletter Coastal Connection can be requested from: 

The Ocean Conservancy

1725 DeSales, Street NW #600

Washington, DC 20036 

Phone: 202-429-5609

Fax: 202-872-0619

References and Further Reading
16-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 16: Marine Debris Unit Two: Physical Measures
Unit Thr

Biological Measur eees

Bacteria: Indicators of Potential Pathogens

Submerged Aquatic Vegetation • Other Living Organisms
Photos (l to r): U.S. Environmental Protection Agency, R. Ohrel, Weeks Bay Watershed Project, R. Ohrel
Chapter 17 Bacteria: Indicators of Potential Pathogens

Direct testing for pathogens is very expensive and impractical, because pathogens

are rarely found in waterbodies. Instead, monitoring for pathogens uses “indicator”

species—so called because their presence indicates that fecal contamination may

have occurred. The four indicators most commonly used today by both volunteer 

and professional monitors—total coliforms, fecal coliforms, E. coli, and

enterococci—are bacteria that are normally prevalent in the intestines and feces of 

warm-blooded animals.
Photos (l to r): S. Schultz, E. Ely, University of Maine Cooperative Extension, University of Maine Cooperative Extension
17-1

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

“Is the water safe?” This is one of the major water quality questions every user of

an estuary wants to know when preparing for a day of swimming, boating, fishing,

shellfishing, or other pursuit. Whether the water is safe depends in part on the

presence or absence of pathogens—viruses, bacteria, and protozoans that can cause

disease. Increasingly, monitoring and regulatory emphasis are focused on the

potential for pathogens that may lead to waterborne diseases. Pathogens can enter a

waterbody via fecal contamination as a result of inadequately treated sewage, faulty

or leaky septic systems, runoff from urban areas, boat and marina waste, combined

sewer overflows, and waste from pets, farm animals, and wildlife. Human illness can

result from drinking or swimming in water that contains pathogens or from eating

shellfish harvested from such waters. 

Direct testing for pathogens is very expensive and impractical, because pathogens

are rarely found in waterbodies. Instead, monitoring for pathogens uses “indicator”

species—so called because their presence indicates that fecal contamination may

have occurred. The four indicators most commonly used today by both volunteer and

professional monitors—total coliforms, fecal coliforms, E. coli, and enterococci—are

bacteria that are normally prevalent in the intestines and feces of warm-blooded

animals, including wildlife, farm animals, pets, and humans. The indicator bacteria

themselves are not usually pathogenic. 

This chapter discusses factors that should be considered when establishing a

volunteer monitoring program for bacteria and reviews the major bacterial indicators

and the analytical methods most commonly used to test for them. Case studies

provide further examples and illustrations.

Overview
17-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

Pathogenic microorganisms

(including bacteria, viruses, and

protozoans) are associated with

fecal waste and can cause a variety

of diseases including typhoid fever,

cholera, giardiasis (a parasitic

infection of the small intestine), and

hepatitis, either through the

consumption of contaminated

shellfish or ingestion of tainted

water. Since these pathogens tend to

be found in very low concentrations

in the water, and there are many

different pathogens, it is difficult to

monitor them directly. Also,

pathogens are shed into the waste

stream inconsistently. For these

reasons, direct testing for pathogens

is expensive and nearly impossible.

Instead, monitoring for

pathogens uses “indicator” species

whose presence in the water

suggests that fecal contamination

may have occurred. The four

indicators most commonly used

today by volunteer and

professional monitors—total coliforms, fecal

coliforms, E. coli, and enterococci—are

bacteria that are normally prevalent in the

intestines and feces of warm-blooded animals,

including:

• wildlife (e.g., deer, geese, raccoons);

• farm animals (e.g., swine, cattle, poultry);

• pets; and

• humans.

States routinely monitor shellfish harvesting

areas for fecal coliform bacteria and close them

to harvesting when the bacterial count exceeds

an established criterion. States may also close

bathing beaches if officials find sufficiently

high levels of fecal coliform bacteria. In addition to bacteria, shellfish are also monitored for

hazards such as viruses, parasites, natural toxins, and chemical contaminants (e.g., pesticides,

mercury, PCBs). (See the U.S. Food and Drug

Administration’s Web site, provided at the end

of this chapter, for more information.)

States monitor heavily used beach and recreation areas as well as the water overlying shellfish beds for total and fecal coliforms, but there

are limits to the coverage they can provide.

Volunteers can supply valuable data to assist

established programs by monitoring areas

where officials are not sampling, thereby augmenting a state’s network of stations. State officials can use this information to screen for areas

of possible contamination. Such expanded coverage helps states make beach- and shellfishclosing decisions on a more localized basis. 

Fecal coliform contamination can frequently

occur in conjunction with other inorganic pollutants. Runoff from a livestock area washing into

an estuary, for instance, may contain not only

fecal coliforms, but high levels of nutrients as

well (see Chapter 10 for more information on

nutrients). By including bacterial counts as one

of a suite of monitoring parameters, a program

manager can design a program that provides a

good characterization of the chosen sites. This

sort of data collection may reveal problem areas

that were not previously recognized. 

Volunteers can also perform fecal coliform

monitoring with an eye toward regulatory compliance. For example, the program may establish monitoring sites near known or suspected

bacterial discharges. Monitoring sites can be set

up adjacent to the discharge, but the effluent

itself can also be sampled. Program managers

should be aware of the legal issues affecting

this type of sampling, such as trespass laws and

the violation of privacy and property rights.

Why do volunteer groups decide to do bacteria testing themselves? The first and foremost

reason is that volunteers are concerned about

their watershed and want the opportunity for

more community involvement and ownership

of the data. Cost is also a factor; unless you

find a lab that will donate the analysis, charges

run $10-$35 per sample, whereas some volunteer monitoring groups spend approximately $2

for each sample they process themselves. 

Why Monitor Bacteria?

Waterfowl are among the many nonhuman sources of bacteria in estuaries

(photo by S. Schultz).

Shellfish beds are closed when

bacteria concentrations exceed

established criteria (photo by 

R. Ohrel).
17-3

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

The Role of Bacteria in the Estuarine

Ecosystem

Bacteria are microscopic single-celled

organisms that function as decomposers in an

estuary, breaking down plant and animal

remains. This activity releases nutrients

previously locked up in the organic matter

into the estuarine food web.

Bacteria live in water, on the surface of

water, in the bottom (benthic) sediments, on

detritus (dead organic material), and in and on

the bodies of plants and animals. They exhibit

round, spiral, rod-like, or filamentous shapes

(Figure 17-1). Some bacterial organisms are

mobile and many congregate into colonies. In

the estuary, bacteria are often found densely

packed on suspended particulate matter. 

Bacteria serve as food for other organisms;

they are also involved in many chemical

reactions within the water. For example,

certain bacteria convert ammonia to nitrite.

Another species converts nitrite to nitrate.

These nutrients are used by plants. Some

bacteria exist only under aerobic

(oxygenated) conditions; others live in

anaerobic (no oxygen) environments. Some

versatile bacteria can

function under either

condition.

Bacterial Contamination 

While bacteria normally

inhabit estuaries as an

integral part of the food web,

human activities may

introduce pathogenic

(disease-causing) bacteria to

the system. Of greatest

concern to public health is

the introduction of fecal

waste from humans or warmblooded animals. Sources of

fecal bacterial contamination

include faulty wastewater

treatment plants, livestock congregation areas,

sanitary landfills, inefficient septic systems,

fecal waste from pets, stormwater runoff, boat

and marina waste, sewage sludge, and

untreated sewage discharge. Wildlife also add

bacteria to waterways, and can be the

dominant source of fecal coliform bacteria in

some areas (Figure 17-2). ■

Bacilli (rods)

Cocci (spheres)

Spirilla (corkscrews)

Septic Systems

Waterfowl

Domestic

Animals

Sanitary Waste

Sewage

Treatment Plants

Wildlife

Wrack Line

Pets Sediments

Stormwater

Runoff

Figure 17-1. Three

shapes assumed by

bacteria.

Figure 17-2. Potential sources of bacteria in an estuary (redrawn from Ely, 1997).
17-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

In this section, the four main indicator

bacteria are discussed. But before we can

understand these indicators, we need to

understand the criteria that were used to select

them as indicators. To be an ideal assessor of

fecal contamination, an indicator organism

should meet as many of the following criteria

as possible:

• The organism should be present

whenever enteric (intestinal) pathogens

are present.

• The organism should be useful for all

types of water.

• The organism should have a longer

survival time than the hardiest enteric

pathogen.

• The organism should not grow in water.

• The organism should be found in warmblooded animals’ intestines.

• The testing method should be easy to

perform.

• The density of the indicator organism

should have some direct relationship to

the degree of fecal pollution (Gerba,

2000).

Total Coliforms and Fecal Coliforms

Coliform bacteria live in the lower

intestines of warm-blooded animals and may

constitute as much as 50 percent of fecal

waste. Although coliform bacteria are not

usually pathogenic themselves, their presence

indicates sewage contamination, perhaps

accompanied by disease-causing pathogens.

Public health agencies have used total

coliforms and fecal coliforms as indicators

since the 1920s. Total coliforms are a group

of closely related bacterial genera that all

share a useful diagnostic feature: the ability to

The Bacterial Indicators

BACTERIA SOURCE TRACKING

Part of interpreting fecal coliform data involves trying to understand the sources of bacteria 

in the estuary. If your monitoring indicates high counts of bacteria, the next step is to examine

the possible sources. To begin “bacteria source tracking,” volunteers should note the number

of wildfowl in the area and observe the scat (excrement) of animals along the beach or shore.

To establish if wild animals are large contributors of bacteria, compare bacteria counts in an

area with few signs of wildlife with an area heavily populated with birds and other animals.

Also investigate whether parts of the watershed have residential areas where dog droppings

can be readily found. It is recommended that monitoring programs work with local agencies

to research possible sources. It is important to look at all the possible sources of bacteria (see

Figure 17-2 for examples), rather than immediately assume that faulty sewage treatment or

failing septic systems are the only culprits.

In addition to careful observation of possible sources and comparing bacteria counts in

different apparent situations, there are other more complex methods used by laboratories to

track bacteria sources. One method uses the fact that some bacteria in humans and

domesticated animals have developed resistance to antibiotics. Colonies of bacteria are

exposed to various antibiotics to help determine if the source of the bacteria is human,

domesticated animals, or wildlife. Other methods, carried out in a few universities and

laboratories, involve the analysis of bacterial DNA.
17-5

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

metabolize (ferment) the sugar lactose,

producing both acid and gas as byproducts.

There are many selective growth media

available that take advantage of these metabolic

characteristics in traditional testing protocols.

Total coliforms are not very useful for testing

recreational or shellfishing waters. Some

species in this group are naturally found in

plant material or soil, so their presence doesn’t

necessarily indicate fecal contamination. Total

coliforms are useful, however, for testing

treated drinking water where contamination by

soil or plant material would be a concern. 

A more fecal-specific indicator is the fecal

coliform group, which is a subgroup of the total

coliform bacteria. Fecal coliforms are widely

used to test recreational waters and are approved

as an indicator by the U.S. Food and Drug

Administration’s National Shellfish Sanitation

Program (NSSP) for classifying shellfishing

waters. However, even this group includes some

species that can have a nonfecal origin (e.g.,

Klebsiella pneumoniae, which grows well in

paper pulp and is sometimes found in high

concentration near paper mills). Studies have

found that all members of the coliform group

can regrow in natural surface water depending

on the water temperature and the amount of

organic matter in it (Gleeson and Gray, 1997).

Some warm tropical waters have sufficient

organic matter for the bacteria to increase in

numbers. The effluents from pulp mills, paper

mills, and wastewater treatment plants may, in

some cases, also provide conditions under which

coliform bacteria can grow. 

Even though fecal coliform bacteria have

some deficiencies when it comes to being a

“perfect” indicator, they are generally

considered the best available indicators of

contamination at the present time. Many citizen

programs and state agencies use fecal coliform

testing to assess potential bacterial

contamination in an estuary. 

One major question often asked about fecal

coliforms and estuaries is: “How long do fecal

coliform bacteria persist in an estuary?” The

answer may vary, depending on where the

bacteria are located in the estuary. For example,

bacteria may survive for weeks in the sediment

or in fecal pellets from wildfowl that

have sunk to the bottom. During a

storm or other event that disturbs the

sediment, fecal coliform bacteria can

become reintroduced to the water

column. Fecal matter also collects in

the line of seaweed and organic

material (called wrack) that can be

seen when the high tide goes out.

Birds and other animals forage for

food and defecate in this wrack line.

When the wrack line enters the water

during high tide or a storm, the fecal

material and associated bacteria also

enter the water. 

Escherichia Coli and Enterococci

Other commonly used indicator bacteria are

Escherichia coli, a single species within the

fecal coliforms group, and enterococci,

another group of bacteria found primarily in

the intestinal tract of warm-blooded animals.

Enterococci are unrelated to the coliforms;

instead, they are a subgroup of the fecal

streptococci group. 

The method approved by the U.S.

Environmental Protection Agency (EPA) for

enterococci testing requires the use of an

expensive growth medium that contains a

toxic ingredient. Volunteer programs

interested in monitoring for enterococci

bacteria could partner with a university or lab

to conduct these tests.

Other Bacteria as Indicators

In addition to the four main indicators

discussed above, there are other bacteria that

can also serve useful indicators of

contamination. These include Aeromonas

hydrophila (a noncoliform), which can be

tested using the membrane filtration method

described later in this chapter. One medium,

ECA Check (made by Micrology

Laboratories), identifies and quantifies

Aeromonas as well as E. coli and total

coliforms. Consult with suppliers for

availability of medium (see Appendix C).

After incubation, any fecal coliform

bacteria in the water sample will have

grown into a colony (when using

mFC medium or broth). These are

called colony forming units (cfu)

(photo by University of Maine

Cooperative Extension).
17-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

Chapter 6 summarized several factors that

should be considered when determining

monitoring sites, where to monitor, and when

to monitor. In addition to the considerations in

Chapter 6, a few additional ones specific to

monitoring bacteria are presented here. 

Due to the costs and training associated

with analyzing water samples for bacterial

contamination, programs just starting up or

those without adequate lab facilities should

strongly consider allowing a professional,

university, or other lab facility to run the

bacterial analyses. Often these labs will run

samples free of charge or at a reduced rate for

volunteer monitoring programs.

Where to Sample

The selection of bacterial monitoring sites

depends on the ultimate purpose of the data.

If the data are to supplement state efforts, for

example, the program should choose sites

based on gaps in the state’s array of

monitoring stations. Areas suspected of

contamination that are not routinely

monitored by state officials should receive the

highest priority. 

If data will serve as regulatory compliance

documentation, sites should cluster near

dischargers believed to be in noncompliance.

State health or water quality agencies can

provide information on where additional data

Total coliforms, fecal coliforms, E. coli, and

enterococci are easy to grow in a lab, and all

will be present in large numbers if recent

fecal contamination has occurred. Unfortunately, one problem with the indicators is the

question of source. All the indicators can

come from animals and some can also come

from plants or soil. Another problem is that

none of the indicators accurately reflect the

potential for human health effects, though

some do a better job than others. Because of

these and other complications, microbiologists

are still looking for better indicators. In the

meantime, volunteer monitors and public

health agencies alike must do their best with

the presently available indicators. 

In 1986, EPA issued a revision to its

bacteriological ambient water quality criteria

recommendations to include E. coli and

enterococci, as they provide better

correlations with swimming-associated

gastrointestinal illness than fecal coliforms.

As an indicator, E. coli has a major advantage

over the fecal coliforms: it is more fecalspecific (E. coli occurs only in the feces of

warm-blooded mammals). 

Why Fecal Coliforms Are the Indicator of

Choice

Even though EPA recommends enterococci

or E. coli for testing recreational waters, many

states still use fecal coliforms. This is partly

for the sake of continuity, so that new data

can be directly compared with historical data.

Another reason fecal coliforms are the

indicator of choice for many states and

volunteer monitoring programs is due to

economics: the EPA-approved method for

testing enterococci can be more expensive

than the fecal coliform test. ■

How Effective Are the Indicators?

Bacterial Sampling and Equipment Considerations
17-7

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

are needed. Government managers are more

likely to use the data if volunteers monitor

more than one site near discharge sources. 

To better understand bacterial

contamination in a particular estuary, it is

necessary to establish the relationship

between flow into the estuary and the extent

of bacterial contamination. Choose sample

sites above and below the area of suspected

contamination, at the effluent’s entry into the

estuary, and even the discharge itself to obtain

a scientifically valid set of data (Figure 17-3).

Bacterial data collected by volunteers can

help assess the relationship between bacterial

density and estuarine conditions, and help

identify bacterial sources.

As previously mentioned, bacteria may

survive for weeks in the sediment, or in fecal

pellets which have sunk to the bottom.

Bacteria in sediment can be tested by stirring

up the sediment before collecting a water

sample. To facilitate data analysis, volunteers

should be careful to identify samples that

contain sediment.

When to Sample

Volunteers should monitor bacteria on a

weekly, biweekly, or monthly basis. In

addition, it may be extremely helpful to

monitor during or immediately after storm

events. It is important to create a monitoring

schedule that is sustainable. Set reasonable

goals for the frequency of monitoring given

your program’s number of volunteers and

financial resources. In areas where volunteers

sample primarily to assess the health risks in

seasonal areas, such as bathing beaches,

monitoring can cease or be conducted much

less frequently during cold-weather months.

Sampling to determine possible contamination

of shellfish beds, however, should continue on

a regular basis throughout the harvesting

season. ■

Reminder!

To ensure consistently high quality data,

appropriate quality control measures are

necessary. As discussed in Chapter 5, it is

very important for volunteers to carefully

follow established protocols so that the

resulting data are of the highest quality. 

With bacteria testing, two quality

assurance/quality control procedures are

especially critical. First, the bacteria

monitoring program should require periodic

split samples, in which one sample is

divided equally into two or more sample

containers and then analyzed by different

analysts or labs. Careful handling of the

water sample is also critical. Some

programs have chain-of-custody forms to

identify the responsible person at every step

of the process. While most volunteer

programs don’t require these forms, the

chain-of-custody can become important if

the data will be used in cases where legal

or corrective actions need to be taken.

Figure 17-3. Sites to monitor for bacterial contamination.
17-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

Some citizen monitoring

programs use volunteers to

conduct the lab analysis of fecal

coliform bacteria, and others

use volunteers to collect the

water samples, leaving the

responsibility of sample

analysis to a professional lab. In

either case, the procedure for

collecting the water samples

requires strict adherence to

quality assurance and quality

control guidelines. Analysis of

the sample should be done

within six hours of the time

when the sample was collected.

Before proceeding to the

monitoring site and collecting

samples, volunteers should

review the topics addressed in Chapter 7. It is

critical to confirm the monitoring site, date,

and time; have the necessary monitoring

equipment and personal gear; and understand

all safety considerations. Once at the

monitoring site, volunteers should record

general site observations, as discussed in

Chapter 7. In particular, they should keep alert

for signs of bacteria sources (e.g., wildfowl or

other wildlife, pets, nearby residences, foul

smells, etc.).

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring an ice cooler (with ice

packs to keep samples cool) and sterilized

wide-mouth sample bottles (over 150 ml) or

Whirl-pak bags.

Sampling Hint:

If using a boat to reach the sampling

location, make sure that it is securely

anchored. It is critical not to bring up the

anchor until the sampling is completed,

since mud (with associated bacteria) may

become stirred into the water.

STEP 2: Collect the sample.

Strict adherence to protocol guidelines is

critical in sampling for bacteria. Contamination from any outside source will skew the

results and invalidate the data. 

Volunteers must take several precautions to

ensure good samples: stay clear of algal

blooms, surface debris, oil slicks, and

congregations of waterfowl; avoid agitating

the bottom sediments; and do not allow the

boat propeller to stir up the water. Wear

gloves when collecting water samples.

Plastic Bottles or Whirl-pak Bags?

For collecting water samples, both plastic

bottles and Whirl-pak bags meet the basic

criteria of being both sterile and nontoxic.

The pre-sterilized, disposable Whirl-pak bags

are convenient, but plastic bottles can be

washed and reused practically indefinitely,

making them cheaper in the long run. In

addition, the bottles are easier to work with

because they stand up on a benchtop.

However, they need to be sterilized in an

autoclave, and this procedure may require

the assistance of a certified lab. Volunteers

should ensure that the bottles they purchase

are autoclavable—some plastics are not.

(Excerpted and adapted from Miceli, 1998.)

Check to see if a current or tide is running

by examining the movement of water or

surface debris. If it is running, sample on the

upstream side of the boat or pier. 

In the Field: 

Collecting Water Samples for Bacterial Analysis

A volunteer with the Friends of the

Estuary/Morro Bay NEP Volunteer

Monitoring Program collects a sample in

a plastic bottle for bacteria testing 

(photo by E. Ely).
17-9

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

Sampling Hint: 

Protect Yourself!

Volunteers should take particular care in

collecting samples, especially near

wastewater discharge pipes, as the effluent

may contain highly pathogenic organisms.

Avoid splashing water, wash hands

thoroughly after water contact, and minimize

the breathing of water vapor. Most

importantly, all volunteers should wear

gloves and protective eyeglasses or goggles.

If using a bottle

• Using a waterproof pen, label the bottle

with site name, date, time, data collector,

and analysis to be performed.

• Making sure to wear gloves, plunge the

bottle into the water upside-down. 

• Open the sample bottle below the water

surface, keeping hands off the bottle

mouth and the inside of the cap. Hold the

lid; do not set it down as it may become

contaminated. 

• Reach down into the water as far as

possible (at least 12-18 inches), still

holding the bottle with its mouth down.

Make sure you keep the bottle above the

bottom so as not to disturb the sediment.

In a single motion, rotate the bottle mouth

so that is it facing up, and sweep the

bottle up and out of the water. Make sure

that the sweeping motion continues until

the bottle is fully out of the water. 

• Pour out enough water to leave about 1

inch of air space in the bottle so that the

lab technician can shake the sample prior

to analysis. 

• Replace the lid, again making sure not to

touch the inside of the cap or bottle rim. 

• Place the bottle in the cooler. Transport

samples back to the lab in a cooler

regulated to between 1°- 4°C. Do not

allow water that may have accumulated

in the cooler from melting ice to

submerge the bottles. To

prevent this problem, use ice

cubes packed in plastic bags,

water frozen in plastic jars,

or sealed ice packs.

If using a Whirl-pak bag

• Using a waterproof pen, write

the following on the outside

of the Whirl-pak bag: site

name, date, time, data

collector, and analysis to be

performed.

• Tear off the perforated top of

the bag. 

• Making sure to wear gloves,

pinch the white tabs on the top

of the Whirl-pak between your

fingers, and place the bag into

the water. 

• Open the bag below the water

surface, keeping hands away

from the inside of the bag. 

• Fill the bag about two-thirds full, and

remove from the water. 

• Leave an inch or so of air space in the

bag. Hold the plastic-coated wire tabs at

the top of the bag with both hands, and

“whirl” the bag quickly around and

around in circles. This will cause the top

of the bag to fold over on itself several

times.

• Seal the bag by pinching the plasticcoated wire tabs together and twisting

them. The bag should not leak.

• Place the bag in the cooler. Transport

samples back to the lab in a cooler

regulated to between 1°- 4°C. Do not

allow water that may have accumulated

in the cooler from melting ice to

submerge the bags. To prevent this

problem, use ice cubes packed in plastic

bags, water frozen in plastic jars, or

sealed ice packs.

A measured amount of a water sample

is being removed from a Whirl-pak

bag prior to testing for the presence of

bacteria. The sample has been kept

cold since it was collected 3 hours

before. Note that the volunteer is

wearing gloves (photo by K. Register).
17-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

STEP 3: Check data sheets, and send off

the sample for analysis.

Volunteers should make sure the samples

remain at the optimal temperature, adding

additional ice if necessary. Recheck the data

sheets for accuracy and account for all

samples. Transport the samples to the

designated lab. Processing of the samples

should start within six hours of sample

collection. Ensure that the data survey forms

are complete and legible. Send the forms to

the appropriate person or agency. As with all

data sheets, the volunteer should make a copy

in case the original becomes lost. ■

In the Lab: Analytical Methods

When testing for the

presence of bacteria,

laboratories generally use

one of two analysis procedures: membrane filtration (MF) or most

probable number

(MPN). Volunteer monitoring groups generally

use the MF procedure, but

may also use presenceabsence tests or one of

the simplified test

methods described below.

Any procedure can be

used for any of the indicator bacteria, simply by

varying such factors as growth media and

incubation temperature. Read the summaries

of each analysis procedure before deciding

which is appropriate for your bacterial

monitoring program.

Membrane Filtration (MF): The Classic

Method for Bacteria Testing

Membrane filtration for fecal coliforms is the

method most widely used by volunteer groups,

who select this method because it is EPAapproved, it conforms to what many state labs

use, and it is a long-established, well-recognized method. For programs that monitor shellfishing waters, MF for fecal coliforms represents a practical way to approximate the methods used by their state shellfishing lab. State

shellfish labs, in accordance with NSSP mandate, use the MPN method for fecal coliforms;

volunteer groups tend to use the same indicator

(fecal coliforms) but not the MPN method. 

Since bacteria are too tiny to count individually, MF relies on an incubation step, followed

by a count of the resultant bacteria colonies. A

known volume of sample water is pulled

through a filter with suction from a vacuum

pump. Bacteria are collected on the top of the

Membrane filtration equipment. Clockwise from

left: membrane filtration apparatus; hand

vacuum pump (syringe and tubing); petri plate

with absorbent pad; membrane filter (photo by

M. Redpath). 

What Levels Are Significant?

Interpreting bacterial data can be tricky. There is a great deal of variability in the test

procedure as well as in the environment, so a firm conclusion cannot be drawn based on just

one sample.

Waterbodies almost always contain some level of fecal coliform bacteria; therefore, it is

strongly recommended that volunteer groups do routine monitoring in dry weather so that they

can know the baseline conditions for their specific sampling sites. Take samples during

different weather conditions and, if possible, collect data during rain events. Consult your

appropriate state agency to learn your state’s standards for bacteria in surface waters.
17-11

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

filter, which is then placed in a petri dish on top

of either solid mFC medium or an absorbent pad

soaked with mFC broth. 

The petri dishes are inverted and incubated for

24 hours (plus or minus 2 hours) at 44.5°C (Hach,

1997). The incubation temperature is the crux of

the membrane filtration with mFC method, since

the ability to grow and ferment lactose at 44.5°C

is the key distinguishing feature of the fecal coliforms group. To obtain accurate counts, the temperature must be held absolutely steady (within

0.2°C): a bit too warm, and the fecal coliforms

can’t grow; a bit too cool, and nonfecal bacteria

start growing. A good-quality waterbath incubator, while not a cheap piece of equipment, is the

least expensive incubator that can provide sufficient results. Air incubators capable of maintaining the required temperature are even more

expensive. Some volunteer programs have tried

building their own waterbath incubators, with

mixed success. Another option is to purchase a

reconditioned waterbath incubator. Check the

Yellow Pages or ask local laboratories to recommend companies that specialize in used and

reconditioned equipment.

After incubation, it is necessary to count the

number of blue-colored fecal coliform colonies.

A 10- to 15-power microscope or illuminated

magnifier is needed to count the colonies. Each

colony has grown from a single bacterial cell, so

by counting the colonies you can obtain a count

of the bacteria present in the water sample.

Results are reported as colony forming units

(cfu)/100 ml, using the following formula:

cfu/100 ml = (coliform colonies counted x 100)/

(ml sample filtered) 

In addition to using mFC medium to investigate

the possible presence of fecal coliforms, the

membrane filtration method can be used with

other media to analyze other indicator bacteria.

The medium used depends on which indicator

you are looking for. Some media contain

ingredients that give the target organisms a

distinctive appearance, such as a color. Other

media require incubation at very specific

temperatures. The amount of time of incubation

also varies according to the medium used. 

Some volunteer monitoring groups use

membrane filtration with mTEC agar, a method

that provides counts for both fecal coliforms

and E. coli. However, this procedure is extrachallenging. In addition to all the steps

described above for fecal coliforms, this

procedure requires the plates to be incubated at

two temperatures (first 35°C and then 44.5°C),

and then a special reagent is used to distinguish

the E. coli colonies from the other fecal

coliforms. 

Equipment Requirements for Membrane

Filtration

Unquestionably, equipment requirements

present the biggest hurdle to volunteer groups

who want to use an EPA-approved method. The

two approved methods volunteers use—

membrane filtration with mFC or with mTEC—

both require an incubator, an autoclave (for

sterilizing equipment), and a membrane filtration

apparatus. On the other hand, once the initial

investment is made, routine testing by these

methods is inexpensive. Many volunteer

programs arrange to use high school or university

laboratories to sterilize equipment, prepare media,

incubate plates, and dispose of wastes. Others set

up the equipment at a central program lab. 

Most Probable Number (MPN) 

The traditional “most probable number”

(MPN) technique (using test tubes) may not be

practical for volunteer groups because it is

labor-intensive, takes up significant incubator

space, and requires up to four days for a final

result. However, it is important for volunteer

estuary monitoring groups to be aware of this

method because MPN for fecal coliforms is the

only method that is NSSP-approved for

classifying shellfish-growing waters.

Unlike membrane filtration, which gives you

a plate of colonies to count, MPN does not yield

a direct count of bacteria. Instead, the water

sample is added to a series of tubes that contain

a liquid medium. After incubation, each tube

shows either a positive or negative reaction for

the target organism. In the case of fecal

coliforms, for example, a positive tube is one
17-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

that shows growth and gas in lactose broth

medium. A second step is required to

“confirm” the positive tubes. The number of

confirmed positives corresponds to a statistical probability that the sample contained a

certain number—the “most probable

number”—of bacteria. The accuracy of the

MPN method can be increased by inoculating

more tubes and by using several dilutions of

the water sample.

Comparing Membrane 

Filtration and MPN

Professional labs mainly use the MF

method of analyses, although some use the

MPN method. The MF technique is good

for large numbers of samples and produces

results more rapidly. It should be noted that

highly turbid water or water with high

counts of noncoliform bacteria can limit

the utility of the MF procedure. If a water

sample is very turbid, the filter in the MF

procedure can become clogged by

sediment, algae, etc.

Presence-Absence Tests

Presence-absence (P-A)

tests are the easiest method

for answering the simple

question of whether the

target bacteria are present in

the water sample. Many

volunteer monitoring

programs use P-A tests to

determine if more extensive

testing is needed. The P-A

test procedure requires that a

bacterial growth medium

(selected based on the

bacteria indicator you are

interested in monitoring) be

added to a water sample in a sterile,

transparent test tube. The test tube is capped,

and the contents are shaken until the medium

is dissolved or totally mixed. The sample is

then incubated for the prescribed length of

time at the required temperature. After

incubation, reading the results usually

requires comparing the color of the sample to

a standard. 

For example, if using the Colilert reagent

(see below) in your P-A test because you are

interested in monitoring total fecal coliforms

and E. coli, you will check the color of the

sample after incubation. A yellow color

confirms the presence of total coliforms. If

yellow is observed, the next step is to check

the sample for fluorescence by placing an

ultraviolet (UV) light within five inches of the

test tube. If the sample’s fluorescence is

greater or equal to the fluorescence of the

standard, the presence of E. coli is confirmed.

Several companies sell P-A test kits; be sure

to carefully read and follow all directions

before using them. 

Special Note About Disposing of

Bacteria Cultures: 

After counting the colonies that have

grown in petri dishes, you will need to

safely destroy the bacteria cultures. Here

are two methods:

Autoclave

Place all petri dishes in a container in an

autoclave. Heat for 15 to 18 minutes at

121°C and at a pressure of 15 pounds per

square inch. Throw away the petri dishes.

Bleach

Disinfection with bleach should be done

in a well-ventilated area, since it can

react with organic matter to produce

toxic and irritating fumes. Pour a 10-25

percent bleach solution into each petri dish.

Let the petri dishes stand overnight. Place

all petri dishes in a sealed plastic bag and

throw away.

Simplified Testing Methods

Because traditional laboratory methods are

complex and can be expensive, several

volunteer monitoring groups have started

using simplified methods to test for total

coliforms, E. coli, and enterococci. The

Volunteers using membrane filtration

equipment. The person on the right is using

a hand-operated vacuum pump to pull rinse

water through the membrane filter (photo 

by E. Ely).
17-13

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

products and procedures outlined below are

alternatives to the approved methods and, in

some cases, can have simpler equipment

requirements. New bacteria monitoring

products are introduced often, so check with

scientific supply houses for new options (see

Appendix C). 

With these simplified methods, there are a

couple of important caveats to keep in mind: 

• These methods are not EPA-approved

for recreational waters (although

Colilert is approved for drinking water)

and thus are appropriate for screening

only.

• None of the quick methods provides a

fecal coliforms count. They only assess

total coliforms, E. coli, or enterococci.

This may be problematic for volunteer

groups whose data users utilize or

require fecal coliform indicators.

The big advantage of these simplified

methods is that they make it possible for

individual volunteer monitors to perform the

tests in their own homes. Incubation is at

35°C or even at room temperature. Some of

the popular simplified methods use the

products listed below. See Appendix C for

addresses of suppliers.

Coliscan Easygel and Coliscan-MF Membrane

Filtration 

Coliscan (from Micrology Labs—see

Appendix C) is a product used by many

volunteer monitoring programs to monitor for

total coliform and E. coli. Coliscan comes in

two pre-packaged kits: Coliscan Easygel

(which is used in a plate-count method) and

Coliscan-MF (which uses membrane

filtration).

Both Coliscan products make use of a

patented medium on which total coliform

colonies other than E. coli appear pink and E.

coli colonies appear purplish blue. With the

Coliscan-MF Membrane Filtration Kit, water

samples are processed by the membrane

filtration technique and the filter is placed on

the special Coliscan medium.

Coliscan Easygel is a very easy

pour-plate method. It is selfcontained and relatively

inexpensive. You simply add the

water sample (unfiltered) directly

to a bottle of liquid Coliscan

medium, mix it, and pour it into a

special petri plate which is coated

with a substance that causes the

medium to gel. Easygel is

appropriate only for counts higher

than about 20 colony forming

units per 100 milliliters (20

cfu/100 ml), since there is no

filtration step to concentrate the

bacteria and the maximum sample

water volume is 5 ml. 

For both Coliscan-MF and

Coliscan Easygel, the

manufacturer recommends an

incubation temperature of 35°C,

but says that plates can also be incubated at

room temperature (though growth will be

slower). However, room temperature can vary

with season or even day to day, making it

difficult to compare results obtained at

different times. Using an incubator ensures a

consistent temperature. 

After incubation, colonies that have formed

in the petri dish are counted. Some users have

found colony counting somewhat tricky with

the Easygel plate because many colonies are

embedded in the agar (since it is a pour plate).

Nevertheless, Easygel can be an effective

screening tool. 

Colilert, Colilert-18, and Enterolert

Some health care agencies, pollution

dischargers, and volunteer monitoring groups

have adopted the use of Colilert and

Enterolert test kits (all made by Idexx

Laboratory—see Appendix C) as alternative

methods for detecting and enumerating total

coliforms, E. coli, and enterococci. Colilert

and Colilert-18 are the media used in MPN

tests to determine if total coliforms and E.

coli are present in the water sample. Colilert

is not intended for marine waters, but

After the water sample is pulled

through the membrance filter (using a

vacuum), the glassware above the

filter is rinsed so all bacteria present

in the sample will accumulate on the

filter. In this laboratory, the membrane filtration process occurs under a

hood for added quality control (photo

by K. Register).
17-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

Colilert-18 is. These kits use either multiple

tubes or multiple wells, with an MPN

approach, to detect the presence or absence of

total coliforms and E. coli. As with the classic

MPN method, the more tubes inoculated, the

more sensitive the count. Five tubes are

enough for a rough screen. 

Results are read after 18 hours for Colilert18 and after 24 hours for Colilert. Incubation

is required at 35°C (plus or minus 0.5°C).

With Colilert, the detection of total coliforms

is based upon a color change and E. coli is

detected when the sample fluoresces under

UV light. This modified MPN test provides

more information about the amount of

bacteria in the water than a presence-absence

test, but not as much information as

an MF or MPN test.

Enterolert is used to detect enterococci in a

water sample using MF, MPN, P-A, or the

modified MPN procedure discussed above.

Incubation is 24 hours at 41°C (plus or 

minus 0.5°C). ■

Case Study: Bacteria Monitoring in California 

In California, several chapters of Surfrider Foundation (a nonprofit environmental

organization dedicated to the protection of the world’s waves, oceans, and beaches) use

Colilert to monitor the surf zone. Surfrider volunteers carry out the tests in their homes or

local school laboratories, using relatively inexpensive incubators. Supplies for each sample

cost about $5.

Surfrider volunteers publish their results in local newspapers and present them at public

meetings. Their efforts are helping to raise awareness about bacteria and nonpoint 

source pollution.

(Excerpted from Ely, 1998.)

Which Method and Which Medium Should You Use?

In deciding what method to use, a number

of questions must be considered. Some of

them are: 

• How do you hope to use your data?

• Will you be testing the freshwater or

saltwater portion of the estuary?

• Will you be testing water where

shellfish are harvested?

• What methods does your state lab

currently use?

• Do you have access to laboratory

facilities?

• What kind of equipment can you afford?

• Which bacteria are used as indicators by

your state?

If your budget allows, select your bacterial

indicator and analysis method based on the

intended use of your data. If the primary

objective of the volunteer monitoring program

is to evaluate water for compliance with state

water quality standards, the program should

use the same or similar method used by state

labs. The program should keep apprised of

any changes in state requirements.

On the other hand, groups that are primarily

interested in raising community awareness

and/or screening for high counts may find that

a simpler, non-approved method is adequate

for their needs. ■
17-15

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

Case Study: Bacteria Monitoring in Maine

The Clean Water Program of the University of Maine Cooperative Extension was

established in 1988. It provides organizational and technical support to 18 citizen

water quality monitoring groups (approximately 600 volunteers). The Clean Water

Program works in collaboration with the Maine State Planning Office Partners in

Monitoring Program, the Maine Department of Marine Resources, and the Maine

Department of Environmental Protection to form the umbrella program known as

the Maine Shore Stewards Program. Water quality groups study the health of

estuarine water by monitoring for dissolved oxygen, temperature, pH, salinity, and

fecal coliform bacteria.

The primary objective of the program is to assist in determining bacterial

pollution sources and to work with local and state officials to remediate those

sources (Figure 17-4). The program focuses at the local community level. Labs

for fecal coliform bacteria analysis are set up in local high schools or community

group locations.

Through their monitoring efforts, citizen groups have

discovered many bacterial sources causing shellfish

bed closures, including unregulated septic storage and

failing septic systems. Working with local officials

and state agencies, the groups helped remedy the

problems and reopen the beds. Due in large part to

these monitoring efforts, 100,000 acres of clam flats

in Maine have been reopened in the past five years.

Other objectives of the program are to monitor coastal

swimming areas and provide baseline data. Recently,

a coastal community with a failing septic system used

volunteer data to determine when bacteria levels were

safe for swimming. In addition, volunteer data has

identified recreational boats as major bacterial sources

in many communities during the summer.

The Maine Shore Stewards Program has built on the strengths of communities by providing them with water quality

and marine resources education, and by assisting them with their work on environmental issues. Partly from their

program participation, many high school students have been inspired to go on to study environmental science in

universities and to become involved in community conservation efforts. Watershed communities have begun working

together to resolve water quality problems, and hundreds of citizens have become active in environmental education

and conservation efforts.

For More Information:

Maine Shore Stewards

University of Maine Cooperative Extension

235 Jefferson Street

P.O. Box 309

Waldoboro, ME 04572

Phone: 207-832-0343

Fax: 207-832-0377

http://www.ume.maine.edu/ssteward

Shore Stewards Volunteers

55%

(5027 samples) Department of Marine

Resources Staff

45%

(4118 samples)

Water Quality Samples 1999

Fecal Coliform Bacteria

Boothbay Harbor Lab

Figure 17-4. Volunteers participating in Maine’s Shore Stewards

Program are instrumental in supplementing state agency-collected

fecal coliform data. Their efforts have helped identify the causes of

many shellfish bed closures (reprinted from Maine Department of

Marine Resources).

Students participating in Maine’s

Shore Stewards Program run estuary

samples for fecal coliform bacteria

using the membrane filtration method

(photo by University of Maine

Cooperative Extension).
17-16

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

Bacteria testing is a very important—and demanding—part of many monitoring programs. Here

are some helpful answers to common questions that may arise (excerpted from Miceli, 1998).

What does it mean when I get a high bacteria count?

The first action to take is to return to the same location and get more samples. If some or all

of these sample results are high, too, then you should follow your organization’s

procedures—for example, calling your state agency to notify them. 

A little detective work plays a big role in determining where contamination is coming from

and whether it is of human origin. Always make observations—the presence of animals and

birds, abundant leaf matter, any strange debris, any unusual smells, etc. Also note weather

conditions since results can vary tremendously if it is raining. 

Remember, too, that variability and unusual test results will occur and that a high level of

fecal coliforms is not abnormal, especially since wildlife frequent estuaries. A long-term

monitoring effort will provide baseline information about a sampling site and will enable

you to quickly recognize any unusual results. 

What exactly am I looking at and counting anyway?

A single bacterium in the water sample that is caught on the filter, if able to grow on the

medium, can reproduce at a fast rate. Some bacteria multiply every 20 minutes, so after 24

hours, when you retrieve your plates, you are looking at a clump of about a million

bacteria—visible to the naked eye! 

I am using the membrane filtration method. Why do I see . . . 

(a) a big blob of growth on only one spot on the filter?

This may occur when the sample aliquot being analyzed is small (1-10 ml) and is not

distributed evenly on the filter. To ensure even distribution, be sure to add enough buffer or

rinse water (5-10 ml) to the funnel prior to adding the sample—and prior to applying the

vacuum. The sample will disperse in the buffer (picture the way a small dollop of cream

spreads out in a cup of coffee), and the colonies should be evenly distributed on the filter. 

(b) all the growth on only one side of the filter?

The funnel base may be clogged so that the vacuum is only pulling through one part of the

base. Remove the base and thoroughly clean it of any buildup. It is recommended that

funnels and bases be cleaned periodically. 

(c) colonies that look runny and oblong?

First, you may be incubating the plates in the wrong position. Plates should be incubated in an

inverted position—that is, medium side up—so that condensation will fall down on the cover,

not on the growing colonies. Second, excessive moisture may remain on the filter if it is

Bacteria Testing Q & A

(continued)
17-17

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

removed before all the sample is filtered. This may cause the bacterial growth to spread out.

These “spreaders” should be counted as one colony. 

There’s a lot of background growth. Can I still count all my target colored colonies?

There is a maximum number of total colonies allowable on a plate. For the small-size

membrane filtration plates, 80 (or even 60, depending on the method) is the maximum. The

larger plates used with Coliscan Easygel can accommodate up to 300 colonies. 

All those organisms compete for the limited nutrients in the medium. The ones that grow are

those that were able to outcompete the others. This competition may mask what the actual

numbers are. If the total number of colonies exceeds the allowable number, the count is

invalid and the result should be reported as an estimate based on the quantity of sample

analyzed and the plate size. 

I have a hard time assessing if a colony is the “right” color.

Including positive and negative control organisms when you analyze your samples will give

you a reference to compare to. It takes practice to learn which questionable colonies are

positive for your method. When starting out, it’s a good idea to pick a representative colony

you are unsure about and verify what it is, perhaps with assistance from a professional lab.

This is especially helpful if an entire plateful of a strange-looking colony appears.

Identifying what it is may uncover an unknown problem in the area or point to a problem

with your quality control. 

On mTEC medium (before you add the urease reagent) some yellow colonies are bigger,

some are smaller, and some are pinpoint, but they should all be considered fecal coliform

colonies. Some may even start to turn a brown-yellow. 

Plates of mFC media are usually easy to count; the one potential problem is crowding, because

the colonies are big and flat. 

Pour plates (such as the Coliscan Easygel plate) can be difficult to read since colonies grow

both on top of and within the medium. The colonies may be smaller and more difficult to

assess when there is a lot of growth. Total coliforms appear pink-red, E. coli appears purple,

and non-coliforms, which are also able to grow, are usually green or white. Lots of

background growth may interfere with “reading” the plates. 

How do I store a plate that I want to send to a laboratory?

If you want to send a plate to a lab for help with identification, place it in a ziplock bag

labeled “biohazard” and store it in the refrigerator, media-side up. Transport the plate to a

laboratory as soon as possible, but the plates can be stored for a week or longer in the

refrigerator because the cold temperature slows bacterial growth. 

(Bacteria Testing Q & A, continued)

(continued)
17-18

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

I gave another laboratory a duplicate sample bottle and their results are very different! Why?

First, be clear about what you are duplicating. If you collect two separate samples from the

same site, you are replicating collection. Since organisms are not homogenous in the

environment, it is very possible that two separate grabs from the same area may yield

different results. 

Most often, what volunteer groups really want to replicate is the analysis. Never use two

separate grab samples to test for comparability of analysis with another laboratory; rather,

collect a single sample in a large container (you may need to buy a few larger sample bottles

for this purpose), mix it well, then immediately pour half into another sterile container

which you will provide to the other laboratory for analysis.

Both laboratories should use the same test method, and preferably both should analyze the

sample at approximately the same time. If the results are not within acceptable limits of

variability, determine where the discrepancy lies. (NOTE: Defining acceptable limits of

variability is a complex problem; consult with a professional lab for guidance.) Common

problems include not mixing the sample well enough prior to analysis, not measuring

accurately, and incorrect incubation temperature. 

What minimum quality control should I be doing?

Briefly, you should maintain records of positive and negative controls, incubator

temperatures, and split sample results. Maintaining proof that your results were generated in

a consistent, reproducible manner that adheres to the requirements of the method will allow

others to accept your results. Quality control testing should not take too much extra time, but

it will instill confidence that you are producing valid data. 

Can I combine my results with others in my program who are using a different method?

No. When reporting results, it is necessary to specify the method used, the media used, and

the lower limit of detection (the smallest number of test bacteria that could be found

considering the method and the quantity of sample). Different methods have different

precision and recovery ability. It is important to separate results that were generated by

different test methods and under different conditions. ■

(Bacteria Testing Q & A, continued)
17-19

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 17: Bacteria: Indicators of Potential Pathogens

Portions of this chapter were excerpted and adapted from:

Ely, E. 1998. “Bacteria Testing Part 1: Methods Primer.” The Volunteer Monitor 10(2): 8-9.

Ely, E. 1998. “Bacteria Testing Part 2: What Methods Do Volunteer Groups Use?” The Volunteer

Monitor 10(2): 10-13.

Green, L. 1998. “Let Us Go Down to the Sea: How Monitoring Changes from River to Estuary.”

The Volunteer Monitor 10(2): 1-3. 

Miceli, G. 1998. “Bacteria Testing Q & A.” The Volunteer Monitor 10(2): 13-15.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A

Methods Manual. EPA 841-B-97-003. Office of Water, Washington, DC. 211 pp.

Other references:

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L.S. Clesceri, A.E. Greenberg, A.D. Eaton (eds). Washington, DC.

Behar, S. 1997. Testing the Waters: Chemical and Physical Vital Signs of a River. River Watch

Network. Montpelier, VT.

Ely, E.. 1997. “Interpreting Fecal Coliform Data: Tracking Down the Right Sources.” The

Volunteer Monitor 9(2): 18-20.

Gleeson, C., and N. Gray. 1997. The Coliform Index and Waterborne Disease. E and FN Spon,

London.

Gerba, C. 2000. “Indicator Microorganisms.” In: Environmental Microbiology. R. Maier, I.

Pepper, C. Gerba (eds). Academic Press, New York.

Hach. 1997. Hach Water Analysis Handbook. 3rd ed. Hach Company. Loveland, CO.

Kerr, M., L. Green, M. Raposa, C. Deacutis, V. Lee, and A. Gold. 1992. Rhode Island Volunteer

Monitoring Water Quality Protocol Manual. University of Rhode Island Coastal Resources

Center, Rhode Island Sea Grant, and URI Cooperative Extension. 38 pp.

Mitchell, M., and W. Stapp. 1999. Field Manual for Water Quality Monitoring. 12th ed.

Kendall/Hunt. Available from GREEN, c/o Earth Force, Inc., 1908 Mount Vernon Ave.,

Alexandria, VA 22301; phone: 703-299-9400; Web site: http://www.earthforce.org/green/.

River Watch Network. 1996. Escherichia coli (E. coli) Membrane Filter Procedure. River Watch

Network. Montpelier, VT.

Stancioff, E. 1996. Clean Water: A Guide to Water Quality Monitoring for Volunteer Monitors of

Coastal Waters. Maine/New Hampshire Sea Grant Marine Advisory Program and Univ. of

Maine Cooperative Extension. Orono, ME.

References and Further Reading
17-20

Volunteer Estuary Monitoring: A Methods Manual

Chapter 17: Bacteria: Indicators of Potential Pathogens Unit Three: Biological Measures

U.S. Environmental Protection Agency (USEPA). 1986. Bacteriological Ambient Water Quality

Criteria for Marine and Fresh Recreational Waters. EPA 440/5-84-002. EPA Office of Water.

PB-86-158-045.

U.S. Environmental Protection Agency (USEPA). 1985. Test Methods for Escherichia coli and

Enterococci in Water by the Membrane Filtration Procedure. EPA 600/4-85-076. EPA Office

of Water. PB-86-158-052.

Web sites:

U.S. Food and Drug Administration, National Shellfish Sanitation Program (NSSP):

http://vm.cfsan.fda.gov/~mow/sea-ill.html and http://vm.cfsan.fda.gov/seafood1.html.

Many manufacturers of bacteria-testing equipment have Web sites that are informative and upto-date on the bacteria-growing media they offer. See Appendix C for Web addresses.

Other resources:

Educational Video on Processing Fecal Coliform Samples

To assist volunteer organizations, a short educational video is available that describes and

demonstrates the analysis of fecal coliform sampling. It includes information for the

layperson on everything from sterilization techniques to QA/QC (quality assessment/quality

control) procedures. The video costs $14 and can be ordered through the New Hampshire Sea

Grant Communications Office, Kingman Farm House, University of New Hampshire,

Durham, NH 03824; phone: 603-749-1565; fax: 603-743-3997.
Chapter 18 Submerged Aquatic Vegetation 

In the shallows of many healthy estuaries, where sunlight penetrates the water to

the estuary bottom, dense stands of aquatic plants sway in unison with the

incoming waves. The aquatic plants are known collectively as submerged aquatic

vegetation. Unfortunately, over the past several decades these plants have fared

poorly in many of our nation’s estuaries. Areas once covered by thick beds of

these plants may have little or no vegetation remaining. In areas that can support

them, the plants often serve as a barometer of estuarine ecosystem health. 

By monitoring the status of these plant populations over time, we can better

determine the estuary’s vitality.
Photos (l to r): K. Register, R. Ohrel, The Ocean Conservancy, E. Ely.
18-1

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 18: Submerged Aquatic Vegetation

In the shallows of many healthy estuaries, where sunlight penetrates the water to

the estuary bottom, dense stands of aquatic plants sway in unison with the

incoming waves. The aquatic plants are known collectively as submerged ( or

submersed) aquatic vegetation. SAV—or sometimes called seagrasses in marine

environments—generally include rooted vascular plants that grow up to the water

surface but not above it (although a few species have flowers or tufts that may

stick a few centimeters above the surface). The definition of SAV usually excludes

algae, floating plants, and plants that grow above the water surface.

The plants are important components of estuarine systems, providing shelter,

habitat, and a food source for many organisms. They also benefit estuarine species

indirectly by helping to maintain the viability of the ecosystem. Their

photosynthesis adds dissolved oxygen to the water, and their leaves and roots help

stabilize the shoreline against erosion. The plants also absorb nutrients, which can

be major estuarine pollutants.

Unfortunately, over the past several decades these plants have fared poorly in

many of our nation’s estuaries. Areas once covered by thick beds of these plants

may have little or no vegetation remaining. 

Not all healthy estuarine and near coastal areas have the physical and chemical

properties necessary to support SAV. For example, areas with very high tidal

ranges (e.g., more than two meters) or soft sediments may not provide a suitable

habitat for the plants. In areas that can support them, the plants often serve as a

barometer of estuarine ecosystem health. By monitoring the status of these plant

populations over time, we can better determine the estuary’s vitality. 

This chapter describes the role of SAV in the estuarine ecosystem, describes

some common SAV species, and provides basic steps for monitoring SAV.

Overview
18-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 18: Submerged Aquatic Vegetation Unit Three: Biological Measures

SAV forms a critical link between the

physical habitat and the biological

community. The plants require specific

physical and chemical conditions to remain

vigorous. In turn, they stabilize sediments and

provide habitat, nourishment, and oxygen to

other species in the estuary. 

A viable and self-sustaining SAV population

is the hallmark of a healthy estuary (in

estuaries that naturally support SAV). By

monitoring the occurrence of SAV beds and

the changes in their distribution, density, and

species composition, trained volunteers can

help determine the health and status of SAV

in an estuary. Scientists can then compare this

information to historical data of SAV beds.

Volunteers and SAV Monitoring

SAV is extremely sensitive to disturbance.

Therefore, it is essential that volunteers

receive proper training and supervision

from qualified scientists or resource

managers. Volunteer leaders should check

with the appropriate government agency to

determine which monitoring or sampling

activities may be suitable for volunteers.

The Role of SAV in the Estuarine

Ecosystem

As critical to the shallow waters of an

estuary as trees are to a forest, SAV beds play

several roles in maintaining an estuary’s

health. Although only a few truly aquatic

species consume the living plants (e.g.,

manatees, sea turtles, and some species of

fish), several types of waterfowl and small

mammals rely on them as a major portion of

their diet. Even in death, the plants are a

major estuary component. SAV forms huge

quantities of decomposed matter as leaves die;

several aquatic species use this detritus as a

primary food source. 

During the growing seasons of spring and

summer, SAV supplies oxygen to the water

through the process of photosynthesis, thereby

helping to support aquatic organisms’

survival. The plants also take up large

quantities of nutrients, which remain locked

in the plant biomass throughout the warm

weather seasons. As the plants die and decay

in autumn, they slowly release the nutrients

back to the ecosystem at a time when

phytoplankton blooms pose less of a problem

(see Chapters 10 and 19).

Additionally, the plant communities provide

shelter for various species of organisms.

Juvenile and larval fish and crustaceans use

SAV beds as protective nurseries and to hide

from predators. Shedding crabs conceal

themselves in the vegetation until their new

shells have hardened. A variety of organisms

[e.g., barnacles, bryozoans (a group of

colonial invertebrates)] and eggs of many

species attach directly to the leaves. 

The sheer bulk of the plants often buffers

the shoreline and minimizes erosion by

dampening the energy of incoming waves.

Plant roots bind the sediments on the estuary

bottom and retard water currents. By

minimizing water movement, SAV allows

suspended sediments to settle and water

clarity is improved.

SAV Habitat Requirements

Once established and under optimal

conditions, these plants can spread quickly

into large, thick stands. SAV habitat

requirements are as follows (adapted from

Bergstrom, 1999):

Adequate Light Penetration

SAV can grow only in those portions of the

estuary shallow enough and clear enough to

receive sufficient sunlight for photosynthesis.

The plants tend to grow in shallow water, but

may grow in deeper areas where the water is

particularly clear.

Why Monitor SAV?
18-3

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 18: Submerged Aquatic Vegetation

Water Inundation

SAV species primarily live in areas where the

plants will remain submerged; however, some

species can withstand exposure during lowwater periods (e.g., low tide). A large tidal

range may limit SAV growth (i.e., prolonged

exposure during low tide and inundation by

deep water during high tide, especially when

the water is cloudy, can make for undesirable

habitat conditions).

Suitable Salinity, Temperature, and Sediments

The salinity, temperature, and sediments of a

particular estuarine location determine, to a

large extent, which species can survive. While

some species tolerate a fairly wide range of

salinity, others are restricted to very specific

levels. 

Low to Moderate Wave Action

Heavy waves impede SAV roots from getting

established. Some water circulation is desirable,

however, to prevent SAV from becoming

choked with algae.

The Demise of SAV 

In a balanced and healthy estuarine ecosystem, SAV species blanket

the shallows with the composition

of each bed attuned to controlling

variables such as light availability,

sediment, salinity, temperature, and

depth. When an estuary is tipped

out of balance, however, SAV beds

usually suffer. The degradation or

loss of these beds can set up a chain

reaction of ill effects that ripples

through the entire estuarine 

ecosystem. 

This chain of events often starts with an overload of nutrients (Figure 18-1). Excessive quantities of nitrogen and phosphorus cause an overgrowth of phytoplankton (see Chapter 19).

These algal blooms cloud the water and severely diminish sunlight penetration. The nutrients

may also trigger a thick growth of epiphytes—

plants that grow on the surface of SAV leaves.

The epiphytes block sunlight from reaching the

leaf surfaces of their hosts. 

Sunlight attenuated by suspended

sediment and phytoplankton in the water

Epiphytic growth

on leaves

Nitrogen and

phosphorus

Resuspended

bottom sediment

from wave action

Shoreline

erosion

Phytoplankton

blooms

Figure 18-1. Impacts on SAV. Sediments, nutrients (and accompanying algal blooms), and epiphytic growth can

ultimately affect the amount of sunlight reaching the plants (adapted from Barth et al., 1989).

As SAV beds decline, the need to

protect them becomes ever more

critical (photo by R. Ohrel).
18-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 18: Submerged Aquatic Vegetation Unit Three: Biological Measures

As the water clarity problem worsens, the

area of the estuary that is able to support SAV

becomes even smaller. For example, estuary

water once capable of supporting plants to a

depth of ten feet may now only transmit enough

light for plant survival to a depth of six feet. 

When plant beds thin or die back, water that

may already be low in dissolved oxygen due to

algal blooms (see Chapters 9 and 19) becomes

even more depleted as the amount of oxygen

generated by SAV photosynthesis declines.

Nutrients once tied up in the plant leaves, roots,

and bottom sediments may be released to the

water where phytoplankton snap them up,

thereby increasing the possibility of more

blooms.

A bare substrate, where SAV once flourished, poses a whole set of new problems.

Without plant roots to stabilize the sediment,

waves easily kick up silt which remains suspended in the water until calmer conditions

return. Like algal blooms, suspended silt cuts

down on light transmission through the water.

The silt may also settle onto the leaves of any

remaining plants, further blocking the light

needed for photosynthesis. 

As some species lose a foothold in the estuary, non-indigenous (or invasive) and opportunistic species may move in and displace them.

Non-indigenous SAV species (e.g., Eurasian

watermilfoil, parrotfeather milfoil, and hydrilla)

may overwhelm native SAV species and

assume their habitat. While the growth of these

new species often alleviates the problems associated with a bare substrate, other problems

may arise (see Chapter 19). 

While nutrients are one of the major causes

of SAV disappearance or decline in many bays

and estuaries (particularly on the Atlantic

coast), other factors may also play a role.

Runoff from different land uses and dredging

activities can cloud waters over acres of SAV

beds with sediment. Agricultural and lawn herbicides may cause a loss of some species, while

industrial pollutants and foraging animals may

selectively kill off local beds. Areas frequently subject to improper shellfish harvesting,

boat-generated waves, and boat propeller

scarring may also lose their SAV beds. ■

Sampling Considerations

What to Sample

There are numerous SAV species with

different ranges throughout the United

States. The type of SAV monitored by

volunteers, then, will depend on

geographic location. A few common and

widely distributed SAV species are

described below:

Eelgrass (Zostera marina) 

Eelgrass (Figure 18-2) is the dominant

seagrass in the cooler temperate zones of

the Atlantic and Pacific coasts. Beds of

this luxuriant plant survive in a wide

range of salinities throughout these

regions, but occur mainly in high salinity

waters (18-30 parts per thousand-ppt)

(Chesapeake Bay Program Web site). Flowing

and elongate like an eel, the slender leaf

blades grow up to several feet in length. 

Eelgrass spreads by sending out runners

that creep along the bottom and repeatedly

send up shoots that grow into new plants. The

species produces tiny, rather inconspicuous

flowers and seeds that appear on large and

easily distinguished branching stalks. New

plants take several years to reach maturation.

Once a bed becomes established, however,

this species of seagrass is highly productive. 

Because of its predominance and

widespread coverage, eelgrass is an important

ecological element of many estuaries and

nearshore areas. It may cover acres of the

bottom, providing food and/or cover for fish,

invertebrates, and waterfowl. 

Figure 18-2. Eelgrass 

(Zostera marina).
18-5

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 18: Submerged Aquatic Vegetation

Eelgrass is subject to infection by a blight

presumably caused by a slime moldlike

organism called Labyrinthula zosterae. The

disease causes dark lesions on the eelgrass

leaves and can ultimately result in mass

mortality of the plant beds. A major epidemic

occurred in the 1930s, but by the 1960s most

beds had recovered. Along with the dieback

of eelgrass, animals dependent on this plant,

such as the brant (a small goose) and bay

scallops (an important economic resource),

also declined precipitously. 

In the past 15 years, scientists and

volunteers have noted the characteristic

lesions of the disease on some eelgrass plants

once again. The blight, also known as eelgrass

wasting disease, is not fully responsible for

eelgrass bed demise. While some areas never

fully recovered from the 1930s epidemic,

other factors have contributed to the plant’s

decline. Nutrient-rich waters, herbicides, and

abundant algal growth have also harmed

eelgrass and other SAV species. 

Volunteers in New England have worked

with a technique to assess the degree of

infestation on individual eelgrass leaves

(Figure 18-3). This information provides an

estimate of disease progression. 

Widgeon Grass (Ruppia maritima)

Widgeon or ditch grass (Figure 18-4)

inhabits the entire Atlantic and Gulf Coasts,

and part of the Pacific Coast of the United

States. This plant is remarkably resilient and

can withstand a wide range of salinities.

Specimens have occasionally been found in

fresh water, yet the species can also tolerate

full ocean salinity. Its primary habitat,

however, is in brackish bays and estuaries. 

The leaves of widgeon grass are needlelike,

short, and usually about two inches in length.

They branch off of slender, elastic stems. Like

eelgrass, this grass produces tiny, rather

inconspicuous flowers and seeds found on

stalks. The plants may also reproduce

asexually by means of rhizomes which extend

along the estuary bottom and send out shoots. 

Widgeon grass is an extremely important

SAV species for waterfowl. The American

widgeon, a brown duck for which the plant

is named, relies heavily upon widgeon

grass as a major component of its diet. The

plant is nutritious, making it a favored

food item for many other waterfowl

species as well. 

Wild Celery (Vallisneria americana)

Wild celery, also known as tapegrass or

freshwater eelgrass (Figure 18-5), is found

along the Atlantic Coast. It is widely

distributed in fresh water, tidal freshwater

rivers, and tidal tributaries to estuaries.

Wild celery has long, flattened,

ribbonlike leaves that emerge from clusters

at the base of the plant. The leaves, which

can grow up to several feet in length, have

a bluntly rounded tip and a light green

stripe that runs down their centers.

Wild celery can reproduce by seed,

rhizome, and tuber. It is an important food

source for waterfowl, particularly the

canvasback duck.

Turtle Grass (Thalassia testudinum) 

Along the Florida and Gulf Coasts, turtle

grass (Figure 18-6) replaces eelgrass as the

dominant seagrass species. Turtle grass

0%

1%

10%

20%

50%

100%

Figure 18-3. Eelgrass wasting disease index key. The disease causes black patches

to appear on eelgrass leaves. Volunteer monitors can use the index to estimate the

disease’s presence on the leaves (Burdick et al, 1993).

Figure 18-4. Widgeon

grass (Ruppia maritima).

Figure 18-5. Wild celery

(Vallisneria americana).
18-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 18: Submerged Aquatic Vegetation Unit Three: Biological Measures

meadows are highly productive and, therefore,

play an important role in estuarine and near

coastal ecosystems. 

Turtle grass plants have broad, straplike

blades, which are wider and shorter than those

of eelgrass. This grass reproduces asexually

by creeping rhizomes or sexually by waterborne flower pollen and forms dense

meadows which often cover vast swaths of

the shallow marine or estuarine substrate. 

Manatee Grass (Syringodium filiforme) and

Shoal Grass (Halodule wrightii) 

Both of these seagrass species are common

along southern Florida and the Caribbean

islands. 

Long and thin, the blades of manatee grass

(Figure 18-7) are light green and up to three

feet in length. Like other seagrasses, this grass

has inconspicuous flowers. Manatee grass

also propagates by rhizome extension.

Manatee grass often mixes with turtle grass in

seagrass meadows. 

Shoal grass (Figure 18-8) has elongate

stalks that often branch into flat, wide leaves

with a maximum width of 1/8 inch. These

stalks may grow to 15-16 inches in length.

They have a naturally ragged, somewhat

three-pointed tip on the leaf. This plant is

aptly named since it inhabits very shallow

areas, generally in water less than 20 inches

deep. While shoal grass beds can grow on

both the landward and ocean sides of turtle

grass beds, they are usually found on turtle

grass beds’ landward sides.

When to Sample

As with all water quality variables,

repetitive measures over a period of years

give a more representative picture of SAV

status than a single sampling approach.

Unlike many of the other variables, however,

volunteers usually need to measure SAV

density and distribution and identify species

only one to three times during the peak

growing season.

The best time of year to sample is when the

SAV species of interest is at its peak biomass

(maximum growth). This varies by species

and location.

Optimal sampling times are close to low

tide on a sunny day when the water is fairly

clear (Bergstrom, 1998). A notable exception

may apply to SAV beds growing in very

shallow water, which may be accessible only

during high tide. In either case, monitors

should try to avoid times when boat traffic is

heavy (e.g., weekends) and the water tends to

be cloudier.

Choosing a Sampling Method

There are several means of monitoring SAV.

Choosing the most appropriate method will

depend on the number and location of sites

already being monitored by volunteers or

others for water quality, the extent of SAV

coverage, the location of problem areas, the

availability of qualified scientists and resource

managers to supervise the activity, and the

planned uses for the collected data. 

Helpful Hint

Collecting plant samples is not generally

recommended. Only properly trained and

authorized personnel should take minimal

samples, if necessary, for positive

identification. 

Before collecting, transporting, or planting

any SAV species, check with the appropriate

government agency about obtaining

necessary permits. 

Observations at Established Water Quality

Monitoring Sites 

Volunteer monitoring programs may choose

to analyze SAV concurrently with several

other water quality variables. In this case, the

simplest option is to estimate the shoot

density of each SAV species in a predetermined radius around the established

monitoring sites (Figure 18-9). No plants

should be removed from the site.

An SAV index (Table 18-1) or other density

scale is a simple means of ranking the density

Figure 18-6. Turtle grass

(Thalassia testudinum).

Figure 18-8. Shoal grass

(Halodule wrightii).

Figure 18-7. Manatee

grass (Syringodium

filiforme).
18-7

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 18: Submerged Aquatic Vegetation

of plants at specific sites. Volunteers estimate

SAV density and classify the bed as falling

within one of three or more density classes.

The data collected from this approach is not

scientifically rigorous and therefore may be

considered only for general education

purposes. The method is, however, a quick

and easy means of obtaining relative

information on the status of an estuary’s 

SAV beds.

Transect Sampling 

In transect sampling, a straight line is

established across an area containing SAV.

Records are made of each plant that touches

the line at predetermined increments (Figure

18-10). If the vegetation is extremely dense,

the data collector can place a rod into the

vegetation at the designated point and record

the different species that touch the rod. The

method provides a rough estimate of the

percent of vegetative cover and the frequency

of each species. 

In a modified version, discrete monitoring

sites can be established along the transect (see

case study, page 18-8). 

Groundtruthing

Groundtruthing is done to verify maps of

SAV beds that some government agencies or

universities create from aerial surveys. The

exercise involves on-the-ground observations

to verify the presence of beds, identify

species, and locate smaller beds that might

not be captured by aerial photography. By

groundtruthing, volunteer groups help

scientists and resource managers get a more

complete picture of year-to-year SAV

distribution. Knowing SAV bed locations and

species composition helps ensure their

protection from activities that

might have a negative impact

on them (see case study, page

18-9).

Groundtruthing requires a

great deal of on-the-ground

effort, and resource agency

personnel and other

professional staff usually

cannot cover the entire aerial

survey area. Volunteers, then,

can provide valuable assistance

in verifying the SAV maps. ■

SAV bed

Transect

line

Figure 18-10. Transect

sampling through a bed

of SAV.

SAV Index Value Category Description

0 None No vegetation present

1 Patchy Small colonies or clumps; sparse bottom coverage

2 Dense Extensive grass beds; lush meadows

Table 18-1. Sample SAV index values. The index may be modified or expanded to include more categories

(e.g., SAV coverage of 0-10%, 10-40%, 40-70%, and 70-100%).

Figure 18-9. SAV shoot

density can be estimated

in a circle around a water

quality monitoring site

(marked with an X).
18-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 18: Submerged Aquatic Vegetation Unit Three: Biological Measures

Case Study: Intertidal SAV Monitoring in Oregon

In 1998, the Tillamook Bay National Estuary Project initiated a four-year study to investigate

the interactions of eelgrass with other estuarine species and its response to human disturbance.

Under the leadership of estuarine researchers,

volunteers collect percent cover and density data on

three different weeklong occasions between May and

September. Intertidal eelgrass is examined, making

volunteers’ time in the field limited to the duration of

the low tide. This limitation requires several

volunteers to help collect data.

At three different intertidal sites, monitors establish

five 30-meter transects and record data at five-meter

intervals along each transect (e.g., at one meter, six

meters, and so on). Using a one-meter square quadrat

made from 1/2-inch PVC pipe, volunteers measure

percent cover and eelgrass shoot density.

To measure percent cover, there are several ways to proceed: visual estimation, photo

digitizing, grid overlay, and others. A “point intercept” method, which utilizes a clear piece of

Plexiglas that has 50 randomly placed dots on it (marked with a permanent ink marker), is

used in this program. The Plexiglas is placed over the experimental plot, and volunteers

observe the item [e.g., sand, eelgrass (including shoots and blades), ulva (a green algae), etc.]

covered by the majority of each dot. Then, a percent cover value is calculated by dividing the

number of each component found by the total number of dots on the Plexiglas. For example:

Determining eelgrass shoot density is somewhat less complex. Volunteers simply count the

number of shoots (not blades) of eelgrass in each quadrat. A researcher familiar with eelgrass

can teach volunteers how to distinguish between eelgrass shoots, blades, and rhizomes.

For More Information:

Tillamook Bay National Estuary Project 

P.O. Box 493 

Garibaldi, OR 97118 

Phone: 503-322-2222

Fax: 503-322-2261

http://www.co.tillamook.or.us/gov/estuary/tbnep/nephome.html

Component # Dots Formula Percent Cover

Eelgrass 31 31÷50 = 62%

Sand 6 6÷50 = 12%

Ulva 13 13÷50 = 26%

Volunteers measuring percent cover and

eelgrass shoot density in Oregon (photo by

Tillamook Bay National Estuary Project

and Battelle Marine Sciences Lab).
18-9

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 18: Submerged Aquatic Vegetation

Case Study: Chesapeake Bay SAV Hunt

Volunteers throughout the Chesapeake Bay region participate in the SAV Hunt, an annual

effort coordinated by the U.S. Fish and Wildlife Service to locate, identify, and map SAV.

The SAV Hunt is used to groundtruth the results of an annual aerial survey. While the survey

provides invaluable information about the location and extent of SAV beds, aerial

photographs have some limitations:

• they miss small beds;

• they don’t identify which species are growing;

• sometimes what looks like a bed of SAV in the photo turns out to be something else

entirely, such as algae growing on underwater rocks or large rocks placed in the water

usually as an erosion control measure; and

• photos are usually taken once a year (or even less frequently), and the SAV species in the

beds change over the growing season.

The SAV Hunters’ on-the-ground observations fill in the missing information; their data are

vital supplements to the aerial survey (see Appendix A for a sample data sheet).

Volunteers select the area they want to survey. They receive a map of that location, showing

where SAV has been found in aerial surveys and previous SAV Hunts. Volunteers also receive

a field guide with line drawings, color photographs, and descriptive text to help them identify

the species. 

A new Maryland law bans clam dredging in SAV beds, and the information provided by

citizens helps identify those areas that are now off-limits to clam dredging. Natural resource

agencies use the information to help target SAV protection and restoration, and local planning

agencies use it when considering approval for construction projects that may affect aquatic

resources. 

For More Information:

SAV Monitoring Coordinator

U.S. Fish and Wildlife Service

Chesapeake Bay Field Office

177 Admiral Cochrane Drive

Annapolis, MD 21401

Phone: 410-573-4500

http://www.fws.gov/r5cbfo/

(Excerpted and adapted from Reshetiloff, 1998.)
18-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 18: Submerged Aquatic Vegetation Unit Three: Biological Measures

Monitoring SAV beds may pose more logistical problems than the measurement of other

water quality variables. Whereas volunteers

measure other variables at set stations, SAV

groundtruthing requires volunteers to go to

areas where the SAV is growing—the plant

beds may not be in exactly the same location

from year to year. 

Although land access to the beds may lie on

private property, landowners are often willing

to provide right-of-way to volunteer monitors.

Water access may be limited by depths too

shallow to accommodate some vessels—

necessitating use of a shallower draft boat

(e.g., canoe, kayak, johnboat, or skiff with

outboard motor). The program manager

should assist each volunteer in solving possible logistical problems before the volunteer

heads for the field. 

General procedures for monitoring SAV

using the groundtruthing method are presented

in this section for guidance only (they are

adapted from the Chesapeake Bay SAV Hunt—

see case study, page 18-9). Monitors should

consult with qualified scientists or resource

managers overseeing the effort on proper

equipment and techniques. Monitors should

also make sure that necessary permits are

obtained before collecting any samples.

Before proceeding to the monitoring site, volunteers should review the topics addressed in

Chapter 7. It is critical to confirm the monitoring site, date, and time; have the necessary

monitoring equipment and personal gear; and

understand all safety considerations. Once at

the monitoring site, volunteers should record

general site observations, as discussed in

Chapter 7. Groundtruthers should be especially

careful to note the tidal stage, weather conditions, water clarity, and the time of day, as these

variables can substantially affect the visibility

of SAV beds.

How to Groundtruth 

SAV Site Logistics

Reaching SAV beds marked on maps may require walking, motoring, rowing, paddling, wading, or swimming. 

Volunteers can reach some SAV beds by walking along the shoreline. Attempt to reach the beds during low tide when they

are in shallower water, but first ensure that the sediments support safe walking.

When using a boat, keep it in sufficiently deep water so that the propeller does not tear up the plants. If the beds are

consistently located in shallow areas, consider using a rowboat, canoe, or even an inflated inner tube as an alternate vessel.

In areas such as the Everglades in southern Florida, volunteers should consider using an airboat. 

Keeping track of map position is extremely important. In areas of vast seagrass beds and few distinct landscape features, it

is particularly easy to get lost. A Global Positioning System (GPS) or compass, used in conjunction with the map, may be a

helpful orientation tool. The volunteer should:

• Travel to the SAV beds marked on the provided map. To find the beds, look for dark patches on the bottom or calmer

surface water surrounded by ripples. The calm water may overlie SAV beds (Bergstrom, 1998). 

• Compare the bed to its noted map position by examining its general location, notable landscape features (natural or

manmade), position relative to the shoreline, and the overall extent of the bed. These distinctions may change from year

to year, but collectively should provide sufficient information to confirm the identity of the bed. 

If you are not sure that you are in the exact spot, if the bed seems to be in a different position than indicated on the map, or if

other aspects of the bed are dramatically different, make sure to note this or record the changes on the survey sheet and map.

Have a companion corroborate your observations if possible.
18-11

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 18: Submerged Aquatic Vegetation

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site:

• map showing SAV beds covering the

study site, as determined from aerial

survey;

• global positioning system (GPS) receiver,

if available;

• weighted and calibrated line to measure

depth, or Secchi disk;

• SAV field identification guide;

• shoes for wading;

• plastic sealable bags (sandwich size);

• labels to go inside plastic bags, or

waterproof marker;

• mask and snorkel or SCUBA, if

necessary;

• instructions for monitoring SAV;

• rake to gather specimen for identification

(see box below for details);

• view tube or hand lens, if available;

• polarized sunglasses; and

• waterproof copy of any required

collection permits.

Raking It In

Unless you get into the water to identify SAV, some kind of tool may be needed to take a minimum number of samples. From a boat or pier, a properly trained person using the right rake is

critical to groundtruthing success. At all times, care should be taken to avoid digging the rake

into the sediment, since this can damage underground roots and rhizomes.

There are several rakes available (see Appendix C for suppliers); however, no one rake will find

all SAV species at all times, and some species simply cannot be collected by raking.

Some recommended rakes are described below, with accompanying photographs on this page.

• A bamboo shrub rake is good for shallow water and SAV with short stems. It works much

better from a canoe or kayak than the more common shrub rake with plastic tines. For

deeper water, an extension pole can be attached. Most shrub rakes have 5-10 tines

(although the bamboo ones have more) and are about 8” across, with a 4’ handle.

• The crab landing net—consisting of a wire basket and long (6’) handle—can be hard to

find, but works well on very short, sparse SAV stems. As the net sweeps through the SAV,

samples are collected in the net junctions. This quality may, however, make it difficult at

times to remove one sample from the net in order to collect another. This net is not recommended for very dense SAV.

• A metal garden bow rake with stiff tines is used by some hunters, but it is probably the least

effective of the four kinds. However, it is the one that most people already have on-hand.

• Though it may be difficult to find, a modified lawn thatch rake can work in water deeper

than the length of a typical rake handle. Adapted with a short handle and rope and called a

“throw rake,” it can be tossed from a boat or pier. As a volunteer pulls it back by its rope,

the rake picks up fairly tall, branched plants, leaving short, unbranched plants behind.

The throw rake can be a useful tool, but extreme caution should be exercised.

As new and more effective designs are found, information will be made available at the U.S. Fish

and Wildlife Service Chesapeake Bay Field Office Web site: http://www.fws.gov/r5cbfo/ under

“Submerged Aquatic Vegetation (SAV).”

(Source: Bergstrom, 2000.)

Several rakes for

collecting SAV samples:

(a) bamboo shrub rake;

(b) crab landing net; (c)

bow rake; and (d) lawn

thatch rake, or “throw

rake,” adapted with a

short handle and rope

(photos by P. Bergstrom,

U.S. Fish and Wildlife

Service).

a

b

c

d
18-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 18: Submerged Aquatic Vegetation Unit Three: Biological Measures

STEP 2: Collect initial data and

map bed area.

If the map already shows the

outline of the bed, use the map’s

name or code for the bed as its

identifier on the data sheet. If the

map contains no record of the bed,

name it according to the format

established by the program

manager. Volunteers will need to

roughly map unidentified beds to

add them to the permanent record.

Those areas marked as SAV beds on the map

but having no plants should be designated on

the survey form by writing “no plants.” 

Indicate the means by which the volunteer

reached the beds (motor boat, canoe, by foot,

pier, etc.).

Use the weighted, calibrated line to measure

depth. A Secchi disk attached to a marked line

can also be used to measure depth. Record the

depth on the survey form.

STEP 3: Monitor SAV.

A bed may contain only one type of SAV or

a variety of species. Move around within the

bed and closely examine several areas to get a

representative assessment of the species

composition. Snorkeling or a view tube may

be needed.

Assessing SAV bed condition

• To identify the plants, carefully use a

rake or another implement to obtain a

small sample of the stems and leaves.

Try not to dig the tool into the sediment

as it may damage underground roots and

rhizomes. It may be necessary to

snorkel or SCUBA for some species that

rakes may not be able to pick up easily

(e.g., eelgrass in summer when it is

short).

• Using the identification guide or a key,

match the specimen to the appropriate

plant. Do not record floating samples,

as they may have come from a

different location. Record the common

name of the plant on the survey form. If

the match is tenuous or the plant does

not seem to resemble any diagram,

place the specimen in a plastic bag and

bring it back to shore for a program

leader to identify. Make sure to label the

plastic bag with the site name, date, and

collector using an indelible marker.

Place one label inside the specimen bag

and another on the outside of the bag as

a precaution against lost labels or

illegible writing. Record the identity of

the collected plant as “unknown” on the

survey form. Any collected sample

should be refrigerated if not examined

right away.

• Examine several different areas of the

bed, estimating density and inspecting

several plants. The program manager

should train volunteers to recognize

symptoms of common diseases or

infestations. 

• If this site has been visited previously,

any noticeable differences, such as

changes in the species composition,

density, bed size, and general plant

health, should be recorded. 

“Mapping” SAV beds

When the SAV bed is unmarked on the map

or has shifted in location, the volunteer should

hand-draw the new location on the map.

Shoreline features, manmade objects, buoys,

shoals, and other landmarks may all be

helpful in marking location. If possible, the

volunteer should use a Global Positioning

System (GPS) unit to roughly establish the

position of the bed (see Chapter 7). 

After completing all steps at the first SAV

bed, navigate to the next designated bed on

the map. Complete the same steps for each

bed and record all information on a new

survey form for each bed. Treat unmapped

beds the same way; after establishing the bed

position on the map, evaluate them like any

other bed. 

Trained volunteer collecting SAV

samples with a lawn thatch rake

(photo by P. Bergstrom, U.S. Fish 

and Wildlife Service).
18-13

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 18: Submerged Aquatic Vegetation

STEP 4: Clean up and send off data.

Volunteers should clean all equipment and

deliver any unknown specimens to the

program manager for plant identification

assistance. The samples should be refrigerated

if they will not be examined immediately.

Ensure that the data survey forms are

complete and legible. Send the forms to the

appropriate person or agency, preferably after

identifying any unknown specimens.

Identified specimens do not need to be sent

with the forms; the program manager should

provide guidance on dealing with the

remaining unidentified plants. As with all data

sheets, the volunteer should make a copy in

case the original becomes lost. ■

SAV Bed Restoration and Monitoring

In an effort to restore SAV populations, many volunteer and professional groups are experimenting with planting SAV

(Bergstrom, 1999).

Even with the right permits and supervision, however, simply planting grasses does not guarantee success. As

photosynthetic plants, they depend on sunlight to survive. A comprehensive monitoring program can provide detailed

information about water clarity and other water quality parameters important to SAV survival. Some programs use

water quality data that volunteers are already collecting to help identify top candidates for SAV restoration projects.

While plants may show growth initially, they may disappear a few years

later. Many volunteer restoration projects do not include follow-up

monitoring to determine their long-term effectiveness. Without water

quality and plant survival monitoring, volunteers are unable to

understand what works and what fails.

Post-restoration monitoring can be a strain on organizational resources.

It requires staff and volunteer time, which may be difficult to spare.

SAV planting projects are usually one-time events, making it easier to

oversee volunteers. Doing the necessary follow-up monitoring, however,

often requires volunteers to work on their own with less oversight by the

program leader (after all, the leader can’t be everywhere at once!).

Because follow-up monitoring may require the use of snorkel or SCUBA

equipment, program leaders might be reluctant to support unsupervised

volunteer SAV restoration monitoring; liability becomes an issue.

The Alliance for the Chesapeake Bay is working with other Bay-area

organizations to standardize SAV monitoring and reporting methods

throughout the region. This effort should improve the groups’ knowledge

of restoration sites and monitoring activities. It is hoped that this

coordination will allow the groups to improve their tracking of SAV

restoration projects.

For More Information:

Alliance for the Chesapeake Bay

6600 York Road, #100

Baltimore, MD 21212

Phone: 410-377-6270

Fax: 410-377-7144

http://www.acb-online.org/index.htm

Alliance for the Chesapeake Bay volunteers use

a 1.0 x 1.0 m frame, constructed with nylon

rope and 2.5 cm diameter PVC piping, to guide

SAV replanting efforts. The frame is divided

into 1/4-meter intervals. At each grid

intersection, two mature plants (called “planting

units”), held together with a biodegradable

staple so that their rhizomes are aligned

parallel, are anchored on the bottom with a

bamboo skewer. Twenty-five planting units

equaling 50 plants per square meter are placed

in each 1m2 grid. The use of the planting grid

allows for the number of plants, and therefore

planting density, to be easily quantified (photo

by B. Murphy). 
18-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 18: Submerged Aquatic Vegetation Unit Three: Biological Measures

Portions of this chapter were excerpted and adapted from:

Bergstrom, P. 1998. “SAV Hunter’s Guide (for Chesapeake Bay).” The Volunteer Monitor 10(2): 17.

Hurley, L. M. 1992. Field Guide to the Submerged Aquatic Vegetation of the Chesapeake Bay. U.S.

Fish and Wildlife Service. Chesapeake Bay Estuary Program, Annapolis, MD. 52 pp. (NOTE:

Out of print).

Other references:

Bergstrom, P. 1999. “Using Monitoring Data to Choose Planting Sites for Underwater Grasses.” The

Volunteer Monitor 11(1): 16-17.

Bergstrom, P. 2000. U.S. Fish and Wildlife Service, Chesapeake Bay Coastal Program, pers. com.

Blakesley, B.A., M.O. Hall, and J.H. Landsberg. 1999. “Seagrass Disease and Mortality:

Understanding the Role of Labyrinthula.” In: The 15th Biennial International Conference of the

Estuarine Research Federation Abstracts. New Orleans, LA. Sept. 25-30, 1999.

Burdick, D. M., F. T. Short, and J. Wolf. 1993. “An Index to Assess and Monitor the Progression of

the Wasting Disease in Eelgrass, Zostera marina.” Marine Ecology Progress Series, 94: 83-90.

Fassett, N. C. 1969. A Manual of Aquatic Plants. University of Wisconsin Press, Madison, WI. 405 pp. 

Gabrielson, P. W., R. F. Scagel, and T. B. Widdowson. 1990. Keys to the Benthic Marine Algae and

Seagrasses of British Columbia, Southeast Alaska, Washington and Oregon. Phycological

Contribution [Dept. of Botany, University of British Columbia, Vancouver]. No. 4. 187 pp.

Hotchkiss, N. 1972. Common Marsh, Underwater, and Floating-Leaved Plants of the United States

and Canada. Dover Pubns, ISBN: 048622810X.

Kerr, M., L. Green, M. Raposa, C. Deacutis, V. Lee, and A. Gold. 1992. Rhode Island Volunteer

Monitoring Water Quality Protocol Manual. URI Coastal Resources Center, RI Sea Grant, and

URI Cooperative Extension. 38 pp. 

Littler, D. S., M. M. Littler, K. E. Bucher, and J. N. Norris. 1989. Marine Plants of the Caribbean: A

Field Guide from Florida to Brazil. Smithsonian Institution Press, Washington, DC. 263 pp. 

Martin, E., and V. Lee. 1991. “Monitoring Diseased Eelgrass.” The Volunteer Monitor 3(1): 13.

Meyers, D. 1999. “Volunteers Add ‘Missing Piece’: Monitoring Restoration.” The Volunteer

Monitor 11(1): 10-11.

Reshetiloff, K. 1998. “SAV Hunt: Citizens Keep Track of Bay Grasses.” The Volunteer Monitor

10(2): 16.

Sheath, R. G., and M. M. Harlin. 1988. Freshwater and Marine Plants of Rhode Island. Kendall

Hunt Publ. Company, Dubuque, IA. 149 pp.

Tampa Bay Estuary Program (TBEP). 1999. Submerged Aquatic Vegetation Monitoring Protocols.

unpbl. Doc. Mail Station I-1/NEP, 100 8th Avenue, SE, St. Petersburg, FL 33701; Phone: 727-

893-2765.

References and Further Reading
18-15

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 18: Submerged Aquatic Vegetation

Tiner, R. W., Jr. 1987. A Field Guide to the Coastal Wetland Plants of the Northeastern United

States. University of Massachusetts Press, Amherst, MA. 285 pp. 

U.S. Environmental Protection Agency (USEPA). 1992. Monitoring Guidance for the National

Estuary Program: Final. EPA 842-B-92-004. Washington, DC.

Web sites:

Chesapeake Bay Foundation: http://www.savethebay.cbf.org

Chesapeake Bay Program: http://www.chesapeakebay.net/baygras.htm

Maryland Department of Natural Resources: http://www.dnr.state.md.us/bay/sav/index.html

University of Hawaii Seagrass: http://www.botany.hawaii.edu/seagrass/

U.S. Fish and Wildlife Service Chesapeake Bay Field Office: http://www.fws.gov/r5cbfo/

Virginia Institute of Marine Science: http://www.vims.edu/bio/sav/index.html
18-16

Volunteer Estuary Monitoring: A Methods Manual

Chapter 18: Submerged Aquatic Vegetation Unit Three: Biological Measures
Chapter 19 Other Living Organisms

While bacteria and submerged aquatic vegetation are popular biological parameters

measured by volunteers, there are other living organisms that deserve—and

receive—attention. Some of these organisms are monitored or collected to screen for

potential problems in the estuary. Others serve to complement chemical, biological,

and physical monitoring activities. For the most part, the monitoring of particular

living organisms represents localized rather than nationwide efforts; that is, for many

reasons, volunteer groups have the desire, equipment, support, and environmental

need to work with these organisms in their particular estuary.
Photos (l to r): E. Ely, E. Ely, T. Monk, R. Ohrel
19-1

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

While bacteria and submerged aquatic vegetation are popular biological

parameters measured by volunteers, there are other living organisms that

deserve—and receive—attention. Some of these organisms are monitored or

collected to screen for potential problems in the estuary. Others serve to

complement chemical, biological, and physical monitoring activities. 

For the most part, the monitoring of particular living organisms represents

localized rather than nationwide efforts; that is, for many reasons, volunteer

groups have the desire, equipment, support, and environmental need to work with

these organisms in their particular estuary.

Clearly, there is a multitude of living organisms that a volunteer group may wish

to monitor to help assess an estuary’s health. This chapter discusses several of

those biological parameters—macroinvertebrates, phytoplankton, and nonindigenous species—and describes their use as environmental health indicators,

identifies sampling considerations, and provides steps for collecting and analyzing

the organisms in the field. 

Overview
19-2

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

Macroinvertebrates are organisms that are

large (macro) enough to be seen with the

naked eye and lack a backbone (invertebrate)

(USEPA, 1997). Aquatic macroinvertebrates

are commonly used in freshwater stream

monitoring as indicators of water quality.

According to the USEPA (1997),

macroinvertebrates make good indicators of

stream quality because:

• They are affected by the physical,

chemical, and biological conditions in

the stream.

• They may show the effects of short- and

long-term pollution.

• They may show the cumulative impacts

of pollution.

• They may show the impacts from

habitat loss not detected by traditional

water quality assessments.

• They are a critical part of the food web.

• Some are very intolerant of and cannot

escape pollution.

The Role of Macroinvertebrates in the

Estuarine Ecosystem

Macroinvertebrates serve many of the same

functions in estuarine systems as they do in

streams. They are critical to the food web.

Some impact water clarity through their

feeding process, filtering with their gills or

other body parts tiny plants, animals, and

The presence, absence, and abundance of

many living organisms can serve as useful

indicators of estuarine health. Some

organisms require relatively clean water to

survive, grow, and reproduce. Their presence

suggests that water quality is good in that

portion of the estuary. Other species are

unfazed or even thrive under poor water

quality conditions. If the number of pollutiontolerant organisms suddenly increases while

pollution-sensitive species disappear or

become difficult to find, the estuary may be

under stress.

Volunteer monitoring of estuarine

organisms, then, can serve as an early

warning device. When biological monitoring

suggests that a water quality problem may

exist, the information can be used to alert

government authorities, who in turn can

intensify their own monitoring efforts to

identify the problem’s cause and solution. The

identification and tracking of non-indigenous

species can be used to further alert us to

human disturbance of estuarine ecosystems.

Early detection networks can help eradicate a

non-indigenous species invasion before it

becomes established.

Monitoring can also be used to complement

chemical, biological, and physical

measurements. Nutrient data, for example,

provide useful information about the types

and quantities of nutrients in the estuary, but

may not tell us enough about potential

impacts. The presence of phytoplankton

blooms provides evidence that nutrient

concentrations may have reached high levels. 

As another example, turbidity and sediment

deposition can affect the survival of many

bottom-dwelling organisms. By monitoring

these animals along with other parameters, we

can gain a better sense of the estuary’s overall

health.

Finally, the collection and analysis of

shellfish for pathogens and toxic materials

complement monitoring for those pollutants in

the water column. ■

Why Monitor Other Living Organisms?

MACROINVERTEBRATES
19-3

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

other materials found in the water. Others, such

as oysters and corals, grow together in groups,

providing valuable habitat for a number of

organisms. Burrowing macroinvertebrates help

aerate bottom sediments.

Unfortunately, using macroinvertebrates as

indicators of estuarine health is more problematic than for streams (Green, 1998; Ely, 1991).

• Estuaries support different

macroinvertebrates than freshwater

systems, with few key freshwater

indicator species living in estuarine

environments.

• Tidal fluctuations and muddy bottoms

make collecting estuarine

macroinvertebrates more difficult than

in streams.

• In contrast with stream systems, there

are as yet no identification keys and

water quality indices, suitable for

volunteers, that link estuarine macroinvertebrates with estuarine health.

As a result of these limitations, volunteer

organizations currently find it difficult to use

macroinvertebrates as indicators of estuarine

water quality. However, that is not to say that

volunteer programs should avoid monitoring

macroinvertebrates altogether. Volunteer monitors are frequently recruited to monitor specific

macroinvertebrate species, such as corals (see

case study, below). Shellfish are other good

examples of estuarine macroinvertebrates that

volunteer groups monitor and sample. 

Shellfish and Estuarine Health

Shellfish often reflect some of the most

important measures of water quality. One way

that volunteers can utilize shellfish is to take

an inventory of their distribution throughout

the estuary (see case study, page 19-4).

Another way is to work with laboratories that

analyze the hazardous compounds in the

animals’ tissues.

With support from the U.S. Environmental Protection Agency (EPA), The Ocean Conservancy manages the Reef Condition

(RECON) Monitoring Program. RECON is an entry-level rapid-assessment protocol for volunteer recreational divers with

an interest in reef conservation issues. The goals of RECON are to broaden the scope of available information about the

benthic (bottom-dwelling) organisms on coral reefs, to alert local researchers and managers of changing reef conditions

(e.g., mass bleaching events, outbreaks of disease, nuisance algal blooms), and to increase public understanding of the

threats to coral reef ecosystems.

RECON divers take a short course from a certified RECON instructor, followed by two practice

dives and a qualifying examination. Divers are trained to collect information about the reef

environment, the health of stony corals, and the presence of key reef organisms and obvious

human-induced impacts. Results of the cumulative data collection are posted on The Ocean

Conservancy Web site for public access and archived for use by the scientific and research

community. 

For More Information:

The Ocean Conservancy

Office of Pollution Prevention and Monitoring

1432 N. Great Neck Road, Suite 103

Virginia Beach, VA 23454

Phone: 757-496-0920, Fax: 757-496-3207

Email: RECON@oceanconservancyva.org

http://www.oceanconservancy.org

Case Study: Coral Monitoring

A volunteer diver

collects data at a coral

reef in the Caribbean

(photo by T. Monk).
19-4

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

Chemical Uptake

Even water that appears clear and untainted

may still contain harmful levels of chemical

pollutants. Shellfish living in the water may

assimilate and accumulate these chemicals

through the intake of polluted water and

sediment or by eating other contaminated

organisms. 

Several types of chemical contaminants can

accumulate in shellfish. These include: 

• heavy metals such as mercury and

cadmium; 

• petroleum hydrocarbons such as

polyaromatic hydrocarbons (PAHs); 

• pesticides such as endrin, dieldrin,

endosulfan, mirex, and malathion; and 

• industrial pollutants such as

polychlorinated biphenyls (PCBs).

Bivalve shellfish, such as clams, mussels,

and oysters, are filter-feeders and strain large

quantities of estuarine water through their

systems to extract small particles of food.

Because they filter such large quantities of

water, however, even relatively low

concentrations of a waterborne contaminant

may eventually translate to high tissue

concentrations. 

Non-bivalve shellfish, such as crabs,

lobsters, and shrimp, are mobile scavengers

which consume plants, small animals, and

detritus from the estuary’s waters and bottom.

Contaminated prey or sediments can produce

high contaminant levels in the tissues of these

shellfish. 

Biological Uptake

Studies or surveys often use shellfish as

indicators of biological contamination as well.

The non-mobile bivalves are particularly

helpful as they pinpoint specific areas of

contamination. 

Shellfish collect fecal bacteria in their gut,

making them good indicators of recent

exposure to sewage waste. Since fecal

coliforms can indicate the presence of human or

animal pathogens, tainted shellfish serve as a

warning and signal that an area may not be

suitable for recreation or fishing. Unlike water

sampling for bacterial contamination (see

Chapter 17), shellfish tissue analysis acts as a

market test; that is, it determines whether the

shellfish are fit for human consumption. 

While some shellfish monitoring programs collect specimens for tissue analysis at a laboratory,

others require only that volunteers count each organism they find in the field.

Tampa BayWatch and the Tampa Bay Estuary Program developed a volunteer activity known

as the Great Bay Scallop Search. During this annual one-day event, volunteer snorkelers patrol

seagrass beds and count scallops along transect lines (see Appendix A for the Scallop Search

data sheet).

The purpose of the project is to document scallop population recovery. Poor water quality

caused scallops to disappear from Tampa Bay during the 1960s. Thanks in part to regulatory

action, the scallops are slowly returning. Stocking efforts are underway to help boost scallop

recovery and establish viable breeding colonies in the bay.

For More Information:

Tampa BayWatch

Phone: 727-896-5320

http://www.tampabaywatch.org

Tampa Bay Estuary Program

Phone: 727-893-2765

http://www.tbep.org/

Case Study: Shellfish Inventories in Florida
19-5

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

Shellfish are easier to collect than finfish

because most tend to move more slowly or

not at all. Moreover, they often congregate—

an oyster bed or a boulder studded with

mussels are two examples—and are fairly

easy to reach. 

Some shellfish are more susceptible to

certain contaminants than others. While a

species may easily tolerate high

concentrations of one chemical, low

concentrations of another can be lethal. 

The life stage of an individual—larva,

juvenile, or adult—will also greatly affect its

response to a toxic substance. In general,

larvae and juveniles are more

vulnerable to injury or death from

exposure to these substances.

Studies of the effects of toxic

compounds must consider both the

age and species of the specimens to fully

assess the chemical’s toxicity. ■

Helpful Hint

Before collecting any organism, check with

the appropriate government agency to

determine whether you will need a permit.

Officials can set predetermined levels of

fecal coliform in shellfish as a management

standard. Areas where levels exceed this

standard should be closed to commercial and

recreational shellfish collection until the

problem is resolved. 

In addition to accumulating bacteria,

shellfish can also consume

phytoplankton, some of which

produce toxins. When shellfish

ingest the phytoplankton, the toxins

accumulate in their tissues. The

toxins can be transferred to humans

who consume the shellfish. ■

Shellfish Sampling Considerations

How to Collect Shellfish

The tests for shellfish contaminants

require sophisticated analyses, expensive

equipment, and rigorous quality assurance

procedures. Trained scientists must perform

these tests to ensure accurate, scientifically

valid results. Volunteers can assist the

scientists, however, by collecting shellfish for

analysis in designated study areas. 

Scientists may need data to: 

• identify areas of concern for a particular

toxic substance;

• aid policy makers in setting regulatory

limits on the recreational or commercial

collection of shellfish species; 

• identify the contaminant sources; 

• examine the effects of particular

contaminants on a species; and 

• determine whether shellfish are safe for

consumption. 

The training of volunteers should include a

session on the identification of the species

required for testing. Most of the popular field

guides for the coastal regions include sections

on shellfish identification. 

Before proceeding to the monitoring site

and collecting samples, volunteers should

review the topics addressed in Chapter 7. It is

critical to confirm the monitoring site, date,

and time; have the necessary monitoring

equipment and personal gear; and understand

all safety considerations. Once at the

monitoring site, volunteers should record

general site observations, as discussed in

Chapter 7. 

Shellfish contaminated

with pathogens or other

pollution indicate that

surrounding waters may

be unsafe for fishing or

swimming. It may be

unsafe for humans to

eat the shellfish 

(photo by R. Ohrel).
19-6

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site for each sampling session:

• field guide for species identification;

• waterproof copy of any required

collection permits;

• collection bucket;

• tools necessary to dig shellfish, dislodge

clustered shellfish, or otherwise collect

targeted shellfish species; 

• sample containers; and

• sample preservative, if necessary.

STEP 2: Collect the shellfish sample.

Once at the sample site, volunteers should

capture animals using the method designated by

the program manager.

The volunteers should carefully label the

sample container in which the animal will be

transported with the date, site name, shellfish

type, and the name of the collector. An indelible

marker is best for ensuring that the labeling is

permanent. Make sure that the sample container

is not wet before using the marker. If required

by the program manager, volunteers should add

a preservative to the sample bottle.

STEP 3: Clean up and send off sample

and data. 

Volunteers should transport the live

specimens at chilled temperatures appropriate

for the species. The program manager should

designate pickup locations for volunteers to

deliver the specimens and supporting data

sheets to program personnel. As with all data

sheets, the volunteer should make a duplicate

in case the original becomes lost.

Make sure to thoroughly clean all

equipment. ■

Very few programs currently use volunteers to collect shellfish for laboratory analysis. The

Department of Health in Washington State, however, has successfully worked with different

volunteer groups to gather shellfish at commercial and recreational beaches. 

Youth Area Watch, managed by the Chugach School District, in Alaska, is also involved with

shellfish collection. Students in the organization collect mussels for scientists who monitor

planktonic activity and production capacity in Prince William Sound.

For More Information:

Washington State Department of Health

Food Safety and Shellfish Programs

Phone: 360-236-3330

Adopt A Beach

4649 Sunnyside Ave. N. #305

Seattle, WA 98103-6900

Phone: 888-57-BEACH or 206-632-1390

Email: aab@halcyon.com

Youth Area Watch

Web site: http://www.micronet.net/users/~yaw/

Case Study: Shellfish Collection in Washington and Alaska
19-7

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

Organisms lacking the means to counteract

transport by water currents are referred to as

plankton, a name derived from the Greek word

planktos for “wandering.” Included in this group

are bacterioplankton (bacteria), phytoplankton

(plants), and zooplankton (animals). In general

all plankton are very small and, in many cases,

microscopic. However, relatively large animals,

such as the jellyfish, are also included in the definition of plankton (Table 19-1; Figure 19-1). 

Phytoplankton are microscopic plants that are common

components of our natural

waters. These plants are algae

and contain an assortment of

pigments in their photosynthetic cells. They are represented

by single cell or colonial forms

that are the primary food and

oxygen producers within freshwater, estuarine, and marine

PHYTOPLANKTON

Taxonomic Grouping Taxonomic Grouping

Phytoplankton

Zooplankton

Crustaceans

Protistans

Ctenophores

Chaetognaths

Coelentertates

Pteropods

Tunicates

Biddulphia

Nitzschia

Thalassiosira

Chaetoceros

Skeletomena

Melosira

Dinophysis

Gyrodinium

Ceratium

Prorocentrum

Chlorella

Cladophora

Codium

Calanus

Temora

Acartia

Coccolithus Phaeocystis

Porphyridium Porphyra

Euthemisto Hyperia

Pleurobrachia Mnemiopsis

Aurelia Physalia

Pyrosoma

Globigerina

Ectocarpus

Euphausia

Podon

Oscillatoria/Trichodesmium Lyngbya

Cryptomonas

diatoms

cryptomonads

coccolithophorids

green algae

blue-green algae

red algae

brown algae

copepods

euphausiids

cladocerans

amphipods

radiolarians 

foraminiferans

comb jellies

arrow worms

true jellyfish

larvacea 

salps

dinoflagellates

Volunteer phytoplankton

monitors at work in Maine.

(a) Samples are collected

using a 1-meter plankton

net. (b) Subsamples are

examined immediately at

100X magnification

(photos by E. Ely).

Table 19-1. Common types of phyto- and zooplankton (see Levinton, 1982).

(a)

(b)
19-8

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

habitats. Zooplankton are animal plankton that

range in size and complexity. They include the

larval forms of large adult organisms (e.g.,

crabs, fish) and small animals that never get

larger than several millimeters (e.g. copepods).

The abundance of planktonic organisms in the

water column follows predictable, geographically based seasonal patterns related to nutrients,

light intensity, temperature, and grazing (predation) pressures. Monitoring the types and relative abundances of plankton populations in conjunction with nutrient and other environmental

parameters can provide significant insight into

the health of an aquatic ecosystem. 

The Role of Phytoplankton in the Estuarine

Ecosystem

Without phytoplankton, the intricate web of

estuarine plants and animals would collapse.

Phytoplankton are primary producers and form

the base of the estuary’s food pyramid. As photosynthesizers, phytoplankton transfer the sun’s

energy into plant matter and provide nourishment for the next level of organisms. 

Phytoplankton are consumed primarily by

zooplankton, which in turn are fed upon by other

larger organisms. If the phytoplankton community is altered in composition or abundance, these

changes may have serious ramifications throughout the food web and upset what may be considered a more favorable balance of life in these

waters.

Water quality conditions will influence the

composition and abundance of phytoplankton.

Since phytoplankton respond rather rapidly to

changes in nutrient concentrations, they are

good indicators of nutrient-rich conditions.

Waters having relatively low nutrient levels are

dominated by diatoms, which are a highly

desirable source of food. In water with higher

nutrient concentrations, cyanobacteria and

dinoflagellates become more abundant. These

phytoplankton species are less desirable as a

food source to animals. 

As nutrients—and consequently phytoplankton—increase, various water quality variables

are affected. Waters with low nutrient levels are

generally clearer than water containing high

concentrations of nutrients. As nutrient levels

increase and the phytoplankton concentrations

become more dense, the water often takes on the

color of the algal pigments (e.g., reddish brown,

green, brown) and odors become noticeable. In

estuaries, the cells frequently collect along tidal

fronts, where their presence is more evident. 

Phytoplankton also influence oxygen concenGreen Algae

Carteria

Dinoflagellates

Gymnodinium

Dinoflagellates

Ceratium

Dinoflagellates

Dinophysis

Diatom

Coscinodiscus

Diatom

Chaetoceros

Diatom

Thalassiosira

Phytoplankton

Copepod

Acartia

Cladoceran

Podon

Blue Crab Zoeae

and Megalops

Calinectes

Zooplankton

Larval Stage

Zoeae

Larval Stage

Megalops

Figure 19-1. Examples of various planktonic forms found in coastal and estuarine waters. 
19-9

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

trations in the estuary. As photosynthesizers,

they produce oxygen, which is critical to all but

a few estuarine organisms. When sunlight is

unavailable (e.g., at night), phytoplankton

respire, removing oxygen from the water.

Oxygen is also consumed when bacteria work

to decompose phytoplankton. A common aftermath of excessive phytoplankton growth in

confined waterways is that oxygen is depleted,

thus producing hypoxic conditions that may

result in the deaths of many organisms.

Levels of Phytoplankton

At certain times, conditions are very good for

phytoplankton growth. When there are adequate

nutrients, increased light intensity, warmer

water, and minimal predation pressures from

zooplankton, phytoplankton population explosions, or algal blooms, may occur. The phytoplankton will continue to bloom until one or

more of the key factors promoting phytoplankton growth is no longer available.

For example, during the spring months in

temperate regions, diatom blooms usually coincide with increases in nutrient levels, water temperature, and light intensity. This increase in

phytoplankton biomass is typically followed by

an increase in zooplankton (often copepods) into

the summer months. During the summer, the

dominant phytoplankton assemblage shifts to

include dinoflagellates and the grazing pressures

of the zooplankton subsides. Another, but smaller, bloom of diatoms occurs in the fall, leading

to a successive repeat in the nutrient/bloom

cycle. Figure 19-2 illustrates seasonal bloom

fluctuations in different geographic locales.

In recent years, there has been an increasing

presence of bloom-forming algae in estuaries

worldwide. This has been attributed to increased

levels of nutrients entering these waters. 

Harmful Algal Blooms 

Some phytoplankton—mostly dinoflagellates

and some diatoms—produce toxins, which have

been known to cause illness or death in many

aquatic organisms, including fish, shellfish, and

marine mammals, by causing lesions, clogging

gills, and depleting oxygen in the water. The

toxins can also have

serious impacts on

humans (Table 19-2).

The toxins can be transferred to humans

through the consumption of shellfish (e.g.,

clams, oysters, mussels,

and scallops). These

organisms feed by filtering water through their

gills to extract various

forms of plankton. The

plankton may not be

toxic to the shellfish, but

they could be toxic to

humans who consume

them. Therefore, state or

local authorities routinely close areas to shellfish harvesting if excessive amounts of toxins

are detected in the water.

One example of a harmful algal bloom is a

“red tide.” It is so named because the bloom is

intense enough to change the color of the water.

Some phytoplankton will produce a reddish,

brown, or green color. In some cases, however,

no color is produced at all—thus dispelling the

myth that there is a definite connection between

abnormally colored water and toxicity.

Although there are many species that can

bloom enough to change the color of the water,

only a few species are toxic.

An increase in the frequency of harmful algal

blooms in the U.S. and worldwide has led to

increased efforts to develop effective monitoring and detection methods. By detecting

blooms early, we can better ensure the safety of

seafood products. The states of Maine and

California have instituted coast-wide volunteer

monitoring programs aimed at early detection

of harmful blooms (Ely, 1998). Other states

have a combination of formal and informal

mechanisms to detect the blooms. The cost of

toxic plankton monitoring is relatively high, so

volunteer monitoring is an important way to

protect public health in a cost-effective manner (Griffin, 1998). ■

Arctic

Temperate

Tropical

J F M A M J J A S O N D

Algae Herbivores

Figure 19-2. Typical

seasonal cycles for

plankton in arctic,

temperate, and 

tropical regions.
19-10

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

Table 19-2. Some toxic phytoplankton important in the United States and their human impacts (excerpted

and adapted from Ely, 1998).

Dinophysis spp. DSP (diarrhetic

shellfish poisoning)

No human illness

reported in U.S.

Gastroenteritis.

Nonfatal.

Phytoplankton Illness Caused U.S. Outbreaks Symptoms

Alexandrium spp. PSP (paralytic

shellfish

poisoning)

New England, West

Coast (including

Alaska)

Numbness of lips and

fingers; lack of

coordination.

Respiratory failure in

severe cases. Can be

fatal.

Pseudonitzschia spp. ASP (amnesic

shellfish poisoning)

No human illness

reported in U.S.

Human illness

reported in Canada

(east coast) and

marine mammal

illness on U.S. West

Coast.

Abdominal cramps,

disorientation.

Permanent memory

loss in severe cases.

Can be fatal.

Gymnodinium breve NSP (neurotoxic

shellfish poisoning)

Mid-Atlantic and

Southeast Coast,

Gulf of Mexico

Gastroenteritis,

painful amplification

of sensation. No

deaths.

Sampling Considerations

When and Where to Sample

As stated in the discussion on algal blooms,

dominant plankton populations change

throughout the year. This should be

considered when planning a sampling

program. For long-term monitoring, a

consistent time period for sampling is needed

for comparability.

What to Sample

In temperate regions, the cyclic pattern of

increased nutrient availability, sunlight, and

algal blooms provides a baseline for

comparison to other spikes in the phytoplankton populations. If an increase in the

numbers of a given species or genus is

conspicuously absent when one normally

Helpful Hint

Adversely affected by strong light, zooplankton groups descend to great depths during the day

and ascend during the night to feed on phytoplankton. Staying in deeper, colder waters during

the day requires less energy for respiration and aids in avoiding predation by fish and seabirds. 

If sampling zooplankton populations, considerations must be made to collect samples from

depths what will yield representative samples of the plankton assemblages being monitored.

This determination should be made as part of the overall planning process and establishment

of a monitoring protocol. 
19-11

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

expects an increase, or vice versa, this may

serve as a warning that some environmental

parameter has changed. In this case, the data

set from phytoplankton monitoring serves as a

general indicator of estuarine conditions. 

Choosing a Sampling Method

Several different methods of obtaining

phytoplankton data are available. The

monitoring coordinator should choose a

method based on the precision of the data

required, the reason for collecting

phytoplankton data, and the money available

for this portion of the monitoring effort. 

Visual Assessment

This method is the easiest and least

expensive way to monitor phytoplankton. In

this approach, volunteers estimate

phytoplankton abundance based on field

observations. This gross assessment of the

waterbody is very limited and should be used

as an indicator to follow-up with a more

rigorous assessment procedure.

Plankton Net Tow

This method uses a cone-shaped mesh net,

towed by boat or by hand along a dock or

bridge through the water, to collect a variety

of plankton species. This approach provides a

decent estimate of phytoplankton density, but

smaller species are likely to be excluded from

the sample because they are able to pass

through the net. If a more comprehensive

quantitative assessment is required for the

taxonomic identification of phytoplankton

species, an alternative method of sampling,

such as water samplers, should be used. 

Water Samplers

If plankton population density measures are

needed (number of cells/liter), then a

monitoring technique to collect a specific

amount of water must be used. A device that

can be lowered into the water to capture a

precise amount of water at a set depth is

needed. 

Traditional water samplers, such as

Kemmerer or Van Dorn (see Chapter 7), are

useful for collecting samples at different

depths, thus ensuring better representation of

the entire plankton community. In addition,

small plankton are unable to escape the

samplers, which is not the case for nets. ■

Reminder!

To ensure consistently high quality data,

appropriate quality assurance and quality

control measures are necessary. See

Chapter 5 for details.
19-12

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

General procedures for collecting and

analyzing phytoplankton samples are presented

in this section for guidance only; they do not

apply to all sampling methods. Monitors

should consult with the instructions that

come with their sampling and analyzing

instruments. Those who are interested in

submitting data to government agencies

should also consult with the agencies to

determine acceptable equipment, methods,

quality control measures, and data quality

objectives (see Chapter 5).

Before proceeding to the monitoring site and

collecting samples, volunteers should review

the topics addressed in Chapter 7. It is critical

to confirm the monitoring site, date, and time;

have the necessary monitoring equipment and

personal gear; and understand all safety considerations. Once at the monitoring site, volunteers should record general site observations, as discussed in Chapter 7.

Besides the general considerations in Chapter 7, each phytoplankton sampling method

involves a specific set of steps. Regardless of

the method used, the program manager should

designate how the data will be provided to

program personnel. If the data is used as an

early warning indicator of harmful algal

blooms, volunteers may need to submit data

sheets immediately (e.g., via fax) to program

staff. As with all data sheets, volunteers should

make a duplicate in case the original becomes

lost. 

When finished sampling, volunteers should

also make sure to thoroughly clean all

equipment with fresh water and store dry. Nets

should be kept out of sunlight whenever

possible.

Specific instructions for measuring

phytoplankton using the different methods are

presented here.

VISUAL ASSESSMENT

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring a Secchi disk to

measure transparency (see Chapter 15).

STEP 2: Record phytoplankton

assessment. 

Estimate the presence of phytoplankton

blooms based on water color, transparency

(using a Secchi disk), and odor. In general, a

waterbody with a significant phytoplankton

bloom will display a green, brown, or red

color, although—as discussed earlier—this is

not always the case. The transparency level

will be considerably reduced when compared

with prior measurements. There may also be

an odor (usually a sulfur or “rotten egg”

smell) due to the decomposition of

phytoplankton cells at the end of the bloom

period. 

PLANKTON NET TOW

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site for each sampling session: 

• properly-sized tow net, sampling

container, and towing apparatus;

• dropper;

• field microscope with slides (e.g.,

depression slides) and slide covers;

• guide for plankton identification; and 

• sample preservative (iodine- or

formalin-based solution for

phytoplankton and zooplankton,

respectively) if species identification

will not be made soon after collection.

How to Monitor Phytoplankton
19-13

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

STEP 2: Collect the sample.

The deployment method of the plankton net

is important, as many phytoplankton

assemblages tend to form clumps within the

water column. Numerous horizontal tows,

done in a diagonal sweep through the water

column, are useful to account for zooplankton

migration patterns and phytoplankton clumps.

A diagonal sweep conducted during a

horizontal tow requires that the plankton net

be deployed to a depth that is 0.5 m off the

bottom. During the tow, the net is pulled

diagonally toward the surface, thus

transecting the water column.

In the horizontal tow method, volunteers

should allow the net to be pulled through the

water for a predetermined distance at a set

speed. Slow speeds are recommended—less

than 3 feet per second if towing manually; 1-3

miles per hour if towing by boat. A record

should be maintained as to the duration of the

tow and distance so that the quantity of water

filtered can be computed and plankton density

derived. 

STEP 3: Calculate density.

Figure 19-3 shows how to calculate plankton

density. The plankton captured by the net

represent the number of organisms in the premeasured volume of water. A slide sample of

0.05 ml (a drop from an eyedropper) should be

prepared and plankton cells counted using a

microscope. Multiplying the number of cells

by 1,000 reveals the number of plankton per

liter. This density figure can then be converted

to the number of individuals per cubic meter,

again multiplying by 1,000. A sample equation

for extrapolating plankton density is given

30

20

10

0

Note: The filter will eventually clog depending upon

the concentration of plankton in the water.

Total volume of water filtered (V)

equals A (the area of the net, ( π x r2 ))

multiplied by D (the distance traveled)

Slow Speed

(1-3 mph if sampling by boat;

less than 3 feet/second if

sampling manually)

V = A x D

(do not mix metric and

English measurements)

Shake to mix and

extract solution with

dropper

Fully rinse net so all

plankton wash into

bottom container

Count plankton in

slide sample

3.14 x radius2

Example:

10 plankton

cells found

1 drop = 0.05 ml

1. To calculate number of cells/liter:

(10 cells/0.05ml) x 1000 = 200,000 cells/liter

2. To calculate number of cells/m3:

200,000 cells/liter x 1000 = 200 million cells

3. To calculate number of cells in entire volume towed (20m3):

 200,000,000 cells/m3 x 20m3 = 4 billion cells

Example:

r = 0.25m

A = πr 2 = 0.20m2

D = 100m

V = A x D = 20m3

Figure 19-3. Plankton sampling using a net tow methodology.

Sample calculations for cell density and total number of cells in

the total volume of water filtered are provided. 
19-14

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

below using a slide sample of 0.05 ml

containing 10 plankton cells:

(a) (10 cells/0.05 ml) x 1,000 = 200,000 cells/liter

(b) 200,000 cells/liter x 1,000 = 200,000,000 cells/m3

Calculating further to determine the total

number of cells in the tow (total volume =

20m3 in our example; see Figure 19-3):

(c) 200,000,000 cells/m3 x 20m3 = 4,000,000,000 cells

The density calculation is only approximate

due to the “net factor”—the effect of the net

as it is towed—forcing some water off the

side rather than through its opening. 

STEP 4: Identify the species.

Plankton collected in the cod-end jar at the

base of the net can also be analyzed microscopically for species identification. Trained volunteers can conduct a gross field analysis of

species found in the water column. A more rigorous laboratory analysis may be needed to

fully quantify species composition and density.

This method could provide a means to establish

a joint research project with a local university.

Species identification must be conducted

soon after collection (4-8 hours), unless a recommended preservative is used. Many phytoplankton samples can be preserved in an iodinebased preservative (e.g., Lugol’s solution),

In 1996, the United States Food and Drug Administration, the Maine Department of Marine

Resources, and the University of Maine Cooperative Extension developed a marine phytoplankton monitoring program for the state. This volunteer-based monitoring effort has proven

to be integral to harvesting safe shellfish.

In this program, community members and students use plankton nets and field microscopes to

monitor for toxic algal species. Guidelines are established for volunteers to quantify their observations on the various species of algae. The volunteers collect data at least once a week, providing valuable information that otherwise would not be available to scientists. The data:

• help agencies identify toxic condition trends and where more thorough sampling is

needed;

• serve as an early warning system for harmful algal blooms, which can lead to

shellfish bed closures; and 

• help officials understand the correlations between toxins in the water column and

toxins in shellfish.

Volunteers receive training on phytoplankton identification and receive preserved samples of

toxic species to take home as references. Agency staff periodically visit volunteers in the field to

help with species identification and to answer questions. Many volunteers simultaneously test

their sites for other water quality parameters to give a more complete summary of estuary health.

For More Information:

Maine Shore Stewards

University of Maine Cooperative Extension

235 Jefferson Street

P.O. Box 309

Waldoboro, ME 04572

Phone: 207-832-0343

Fax: 207-832-0377

http://www.ume.maine.edu

Case Study: Searching for Toxic Phytoplankton in Maine
19-15

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

which “fixes” the sample and stains the cellulose walls of the phytoplankton cells to aid in

identification. A zooplankton sample should be

preserved using a formalin-based solution.

WATER SAMPLE

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site for each sampling session:

Gross Density Sample Technique

• sampler (e.g., Kemmerer, Van Dorn, or

plankton net); 

• dropper;

• field microscope with slides (e.g.,

depression slides) and slide covers;

• guide for plankton identification; and 

• sample preservative (iodine- or formalin-based solution for phytoplankton and

zooplankton, respectively) if species

identification will not be made soon

after collection.

Composite Cell Count Technique

• sampler (e.g., Kemmerer or Van Dorn

sampler); 

• 500 ml labeled bottles;

• guide for plankton identification; and 

• sample preservative (iodine- or formalin-based solution for phytoplankton and

zooplankton, respectively).

STEP 2: Collect the sample.

Using a Kemmerer or Van Dorn sampler,

collect plankton samples from various depths.

In many cases, phytoplankton clumps within

the water column can cause problems for

analysis. These problems can be compensated

for in multiple and/or composite samples. 

STEP 3: Analyze the sample.

Samples can be analyzed using the gross

density sample technique or the composite

cell count technique.

Gross Density Sample Technique

The collected water can be poured through

the mesh of a plankton net where the plankton

are strained out of the water sample. Calculate

density as explained in the plankton net tow

method and Figure 19-3. 

It should be noted that a density figure

calculated from a mesh-strained plankton

sample will likely not contain the smaller

phytoplankton forms as they will pass through

the mesh of most plankton nets. To obtain a

more accurate density measure, an alternative

method of analysis (e.g., composite cell

count) should be used to better assess the

types and numbers of phytoplankton cells

obtained in each sample.

Composite Cell Count Technique

Using water sampling devices such as a

Kemmerer or Van Dorn, collect a series of 1-

liter volumes of water from predetermined

areas representing vertical and horizontal

distributions. Combine these samples into a

larger, composite sample. This method of

creating composite samples provides the

mechanism to reduce the effects of distribution

patterns of phytoplankton assemblages and

also ensures that a better sampling is obtained

of smaller phytoplankton forms for analysis as

the sample is not filtered through a mesh. 

While in the field, mix the composite

sample thoroughly and pour subsamples into

500 ml labeled bottles containing a

preservative solution. At a laboratory, these

samples will be processed into concentrates

for more rigorous microscopic analysis.

Volunteer monitors can be trained to scan slide

samples of these composite samples to

determine species types and density levels.

This method could provide a means to

establish a joint research project with a local

university. ■
19-16

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

Another procedure for determining the

abundance of phytoplankton is to measure the

amount of chlorophyll that is present.

Chlorophyll is a pigment common to all

photosynthetic algae, and its amount in the

water is in relation to the algal concentration.

This analysis is conducted in a laboratory

where the density of chlorophyll may be

determined with appropriate instrumentation. 

Three replicate water samples, often

ranging from 250-500 ml, are usually taken

for this analysis. The samples should be

collected in opaque bottles, which are placed

on ice, kept in the dark, and transported to a

laboratory. 

In the lab, the water sample is processed

through a glass fiber filter, which is then

placed in acetone and ground up. Technicians

measure the amount of chlorophyll in the

processed sample using a fluorometer, an

instrument that measures the fluorescence of a

substance. If the laboratory cannot process the

sample immediately, it may be frozen and

filtered at a later date. ■

Special Topic: Chlorophyll Collection for Lab Analysis

NON-INDIGENOUS SPECIES

Recently, attention has been given to the

great numbers of organisms that have been

introduced to ecosystems outside their normal

range of occurrence. These “alien invaders”

are known by many names, including nonnative species, non-indigenous species,

nuisance species, invasive species, and exotic

species. Regardless of the name, some of

these organisms can wreak havoc on any

ecosystem—including estuaries—once they

become established.

Non-indigenous species (NIS) enter

estuarine systems by a variety of pathways.

These include:

• Boats and Ships

Vessels often take on ballast water and

sediment to keep them stable at sea. Often,

the ballast and associated sediment contain

small aquatic plants, animals, and

pathogens which can be introduced to the

estuary when the ballast is discharged near

ports. Fouling organisms (e.g., barnacles)

on the vessel’s hull can also be transported

to different regions. Plant fragments get

caught on boat propellers and fishing gear,

creating another introduction pathway.

• Seafood Imports and Processing

Packing materials for live seafood (e.g.,

seaweed and seawater) can contain living

organisms. When materials are improperly

discarded, species introductions are

possible. Organisms living in or on seafood

can also find a way into the estuary.

• Aquaculture and Fishery Enhancement

This includes introductions of nonindigenous fish and shellfish that are

intentionally released to the estuary or

escape from captivity. Intentional

introduction of one species can

inadvertently bring other associated

species, such as parasites.

• Biological Control

Some organisms are introduced to control

the growth and spread of other species. 

• Artificial Waterways

Channels, canals, and locks are artificial

connections between waterways. They

facilitate movement of various organisms to

new locales via vessels or natural spread.
19-17

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

• Live Bait

Bait species and their packing material can

be intentionally and accidentally released to

the estuary.

• Research and Education

Laboratories, schools, and aquariums use

NIS for testing, teaching, and research.

Poor management can allow organisms to

escape or be intentionally released.

• Aquarium and Nursery Trades

These industries transport and sell NIS.

Intentional releases and escapes of

organisms can lead to NIS invasions.

• Natural Spread

Some organisms are transported to new

locations by natural means, including

migration and transport (e.g., by birds,

insects, natural floating debris, etc.).

NIS have been introduced into

environments for hundreds of years, but the

rate of these introductions is increasing,

thanks in part to greater and faster

international shipping traffic and international

trade. The problem of NIS is worldwide and

involves nearly all taxonomic groups

(Heimowitz, 1999).

The Role of NIS in the Estuarine

Ecosystem

Some NIS have impacts on estuarine

ecosystems that are being felt in many ways.

The following sections describe these various

impacts:

Ecological Impacts 

Many NIS are relatively innocuous to their

new environments; others, however, are

notorious for causing major problems to

estuarine ecology. In fact, NIS are the second

most significant threat to threatened and

endangered species, behind only habitat loss

(Wilcove et al., 1998).

Through predation and competition, NIS

have disrupted many native populations—

some to the point of total disappearance from

the estuarine system. Because many NIS have

few, if any, predators or competitors in their

new homes, they are able to reproduce

essentially unchecked. As a result, they

dominate their habitats and cause a reduction

in biodiversity.

NIS can also affect habitats. Atlantic smooth

cordgrass, for example, is native to the eastern

United States but has been introduced to the

Pacific Northwest. It is now causing havoc

along Pacific Northwest estuaries, where it

traps sediment and converts extensive

mudflats to nearshore meadows. The increased

elevation and root mass displaces animal

communities adapted to surviving in the mud,

destroys foraging habitat for fish and birds,

and out-competes other plants that are

included in animals’ diets (Coastlines, 1999). 

Other impacts are also being seen. Some

non-indigenous herbivores (plant-eating

animals), such as the nutria, have decimated

wetland, marsh, and submerged aquatic

vegetation. This leads to increased erosion and

loss of food and habitat for native species.

Some NIS crossbreed with native species, a

situation which can ultimately lead to local

extinction of the natives. NIS may also carry

diseases or parasites with them, against which

local species have no defense. Finally, some

NIS can transform estuarine chemical

dynamics, exposing the food web to new or

increased amounts of toxins.

Human Health Impacts

Some NIS threaten human health. Ballast

water discharges are suspected as causes of

bacterial and viral outbreaks. Ballast water

can also contain the dinoflagellates which

cause red tides (see previous sections in this

chapter). These occurrences can have severe

health consequences for people who swim,

boat, or eat fish or shellfish from contaminated waters. 
19-18

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

Socio-Economic Impacts

Not only can NIS have significant impacts on

ecosystems and human health, but they also

exact a great financial cost. NIS that grow in

unchecked abundance can clog water intake

pipes (the zebra mussel is probably the most

notorious NIS in this regard) and cause

instability to levees. These problems keep

municipal utilities and land managers on the

lookout, and cost millions—even billions—of

dollars to address. One study has estimated that

environmental damages caused by NIS add up

to $138 billion annually (Pimentel et al, 1999).

In the marine environment alone, it costs $5

billion each year to control NIS (Valigra, 1999).

Because of the damage they cause to native

populations, NIS can have a direct impact on

local fisheries. The Chinese mitten crab has

been blamed for shutting down fish salvage

operations in the Sacramento River delta. In the

Chesapeake Bay, scientists and watermen fear

that the recently discovered veined rapa

whelk—an Asian native with a voracious

appetite for shellfish—will decimate the region’s

already suffering oyster and clam fisheries.

Levels of NIS Invasion

All estuaries in the United States probably

have some NIS, but no one knows exactly

how many. San Francisco Bay is one of the

most invaded estuaries in the world,

supporting approximately 230 non-indigenous

organisms (Cohen and Carlton, 1998).

Approximately 160 NIS are known to infest

the Chesapeake Bay (SERC Web site), and

the numbers are growing. ■

Non-Indigenous Species: A Different Kind of Pollution

Non-indigenous species (NIS) are viewed as a biological pollutant requiring management under

the federal Clean Water Act. NIS is markedly different from most traditional pollutants, however.

Unlike many other forms of pollution, such as nutrients, oil spills, or sewage, NIS do not eventually dissipate over time. Instead, they grow and reproduce, spreading their impacts throughout the

estuary. Because of this characteristic, an NIS is very difficult to eliminate once it becomes established. Consequently, prevention and early detection are the only cost-effective options for keeping NIS out of estuaries.

Sampling Considerations

Once non-indigenous species become

established, they are very difficult—or even

impossible—to eradicate. Therefore, early

detection of NIS invasions is critical. Volunteers

can serve an important function by working

with experts to find NIS. In fact, one of the

most firmly established and destructive species

in the San Francisco Bay area—the Asian

clam—was first discovered by a college

biology class doing basic monitoring exercises

in 1986 (Sheehan, 2000).

NIS include the full range of plants, animals,

and microbes, so sampling approaches will vary

depending on the species. To help find and

control NIS, it is important to understand the

organisms’ life histories and habitats (Graves,

1999). Awareness of native natural history is

important for volunteer monitors, who may not

know all NIS in the region but can at least

recognize what doesn’t look typical. ■

Helpful Hint

It may be illegal to possess or transport

certain NIS specimens. Volunteer leaders

should check with the appropriate

government agency about obtaining the

necessary collection and transport permits.

Obtain the permits before starting any

sampling activities.
19-19

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

Because NIS include nearly all taxonomic

groups, there is no standard procedure for

monitoring them. Monitors should therefore

consult with their data users to determine

acceptable equipment, methods, quality

control measures, and data quality

objectives (see Chapter 5) for their

organisms of interest.

Regardless of the method used, volunteers

should review the topics addressed in Chapter

7 before proceeding to the monitoring site and

collecting samples. It is critical to confirm the

monitoring site, date, and time; have the

necessary monitoring equipment and personal

gear; and understand all safety considerations.

Once at the monitoring site, volunteers should

record general site observations, as discussed

in Chapter 7.

The training of volunteers should include a

session on the identification of the organisms

of interest. 

STEP 1: Check equipment.

In addition to the standard sampling

equipment and apparel listed in Chapter 7, the

volunteer should bring the following items to

the site for each sampling session:

• guide to aid species identification;

• equipment necessary to collect and

transport the organism(s) of interest;

• waterproof copy of any required species

collection/transport permits; and

• sample preservative, if necessary.

STEP 2: Collect the sample.

Volunteers should capture the organisms

using the method designated by the program

manager and approved by the data users.

The volunteers should carefully label the

sample container in which the organism will

be transported with the date, site name,

organism name (if known), and the name of

the collector. An indelible marker is best for

ensuring that the labeling is permanent. Make

sure that the sample container is not wet

before using the marker.

STEP 3: Clean up and send off sample

and data.

Volunteers should transport live specimens

at chilled temperatures appropriate for the

species collected in containers supplied by the

program. The program manager should

designate pickup locations for volunteers to

deliver the specimens and supporting data

sheets to program personnel. As with all data

sheets, the volunteer should make a duplicate

in case the original becomes lost.

Make sure to thoroughly clean all

equipment. ■

Hunting for NIS—and Bounty

In 1999, the Virginia Institute of Marine

Science began offering a bounty for the

veined rapa whelk. Citizens collect and

donate the animals in return for money or 

t-shirts.

The project is used to help scientists

document the whelk’s distribution in the

Chesapeake Bay and investigate potential

impacts on the Bay’s ecosystem.

For More Information:

The Virginia Institute of Marine Science 

P.O. Box 1346 

Gloucester Point, VA 23062-1346 

Phone: 804-684-7000

http://www.vims.edu/fish/oyreef/rapven.html

How to Monitor Non-Indigenous Species
19-20

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

Spreading northward from California, the non-indigenous European green crab

(Carcinus maenas—see Figure 19-4) first appeared on the Oregon coast in 1997. By

1999, green crabs occupied most Oregon estuaries, Washington’s Willapa Bay and

Grays Harbor, and sites in British Columbia. A capable predator, this invader raises

concerns about impacts to native and commercial shellfish in the Pacific Northwest.

Given the invasion rate and extensive area at risk,

agency monitoring alone is insufficient to detect the

spread of the green crab. Volunteer programs provide

many more sets of eyes to watch for this species as well

as other NIS invasions.

To help the public distinguish green crabs from similar

native crabs, Oregon and Washington Sea Grants have

produced a color photo identification guide. In addition,

Washington Sea Grant (with support from the U.S.

Department of Fish and Wildlife) held a workshop for

volunteer groups to provide information on green crab

biology and monitoring techniques. Washington State’s

Department of Fish and Wildlife has contracted with

Adopt-A-Beach, a nonprofit volunteer group to train and

coordinate volunteers on green crab monitoring.

Between July and September of 1999, 35 volunteers were trained and 32 monitoring

sites, ranging from south Puget Sound to the San Juan Islands and the U.S.-Canadian

border, were established. Volunteers search for the crab using baited traps in the

intertidal zone.

Through the combined actions of agencies, tribes, schools, and volunteers,

approximately 80 sites are monitored for green crabs in Washington. Numerous efforts

to track the status of the green crab in Oregon estuaries also continue. For example,

volunteers and high school students along the northern coast are monitoring for green

crabs using live bait and modified minnow traps in six estuarine and marine sites.

For More Information:

Case Study: Keeping Tabs on Green Crabs in the Pacific Northwest

Figure 19-4. The

European green crab,

which can have severe

environmental and

economic impacts in the

Pacific Northwest.

Washington Department of 

Fish and Wildlife

1111 Washington St. SE

Olympia, WA 98501

Phone: 360-902-2200

Fax: 360-902-2230

Oregon Sea Grant, 

Marine Invasive Species Team

500 Kerr Admin. Bldg., OSU

Corvallis, OR 97331-2131

Phone: 541-737-2714

Fax: 541-737-2392

Washington Sea Grant, 

Marine Invasive Species Team

3716 Brooklyn Avenue NE

Seattle, WA 98105-6716

Phone: 206-543-6600

Fax: 206-685-0380
19-21

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

Volunteers have many opportunities to become involved in biological monitoring activities.

This chapter discusses just a few organisms monitored by volunteers. Below are references

to other biological monitoring parameters. Volunteer leaders should contact their state

monitoring agencies for information on other monitoring opportunities.

Birds

• “Bird Monitoring in North America”-U.S. Geological Survey Web site: 

http://www.mp1-pwrc.usgs.gov/birds.html.

• International Black Brant Monitoring Project: http://www.sd69.bc.ca/~brant/.

(See also Alexander, G. 1998. “The International Black Brant Monitoring Project:

Education That Spans a Flyway.” Coastlines 8.2. Web site: http://www.epa.gov/owow/

estuaries/coastlines/spring98/blackbrt.html.)

Salt Marshes/Wetlands

• Ferguson, W. 1999. “Fixing a Salt Marsh: Citizens, Shovels, and Sweat.” The Volunteer

Monitor 11(1). Web site: http://www.epa.gov/owow/volunteer/spring99/index.html.

• Bryan, R., M. Dionne, R. Cook, J. Jones, and A. Goodspeed. 1997. Maine Citizens

Guide to Evaluating, Restoring, and Managing Tidal Marshes. Falmouth, ME. Web site:

http://www.maineaudubon.org.

• Lipsky, A. 1996. Narragansett Bay Method: A Manual for Salt Marsh Evaluation. Save

the Bay, Providence, RI. 22 pp. (Save the Bay, 434 Smith St., Providence, RI 02908-

3770; phone: 401-272-3540).

• The Volunteer Monitor 10(1). 1998. Issue Topic: “Monitoring Wetlands.” Web site:

http://www.epa.gov/volunteer/spring98/index.html.

Replanting/Restoration Projects

• The Volunteer Monitor 11(1). 1999. Issue Topic: “Restoration.” Web site:

http://www.epa.gov/owow/volunteer/spring99/index.html.

Biological Monitoring: Something for Everyone
19-22

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures

—. 1999. “The Cordgrass Is Not Always Greener on the Other Side.” Coastlines 9.5: 6-7.

American Public Health Association (APHA), American Water Works Association, and Water

Environment Federation. 1998. Standard Methods for the Examination of Water and

Wastewater. 20th ed. L.S. Clesceri, A.E. Greenberg, A.D. Eaton (eds). Washington, DC.

Cohen, A.N., and J.T. Carlton. 1998. “Accelerating Invasion Rate in a Highly Invaded Estuary.”

Science 279: 555-557.

Cushing, D.H. 1975. Marine Ecology and Fisheries. Cambridge Univ. Press. 278 pp.

Ellett, K. 1993. Chesapeake Bay Citizen Monitoring Program Manual. Alliance for the

Chesapeake Bay. Richmond, VA. 57 pp.

Ely, E. 1991. “Benthic Macroinvertebrate Monitoring in Estuaries—A New Direction for

Volunteer Programs?” The Volunteer Monitor 3(1): 5.

Ely, E. 1994. “The Wide World of Monitoring: Beyond Water Quality Testing.” The Volunteer

Monitor 6(1): 8-10.

Ely, E. 1998. “‘Early Warning System’ for Shellfish Poisoning.” The Volunteer Monitor 10(2): 4-7.

Graves, J. 1999. “Exotic Species” In: Meeting Notes—U.S. Environmental Protection Agency

(USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary Monitoring:

Wave of the Future. Astoria, OR: May 19-21, 1999.

Green, L. 1998. “Let Us Go Down to the Sea: How Monitoring Changes from River to Estuary.”

The Volunteer Monitor 10(2): 1-3.

Griffin, K. 1998. A Citizen’s Guide to Plankton Monitoring in Tillamook Bay. Tillamook Bay

National Estuary Project, Garibaldi, OR. 45 pp. 

Heimowitz, P. 1999. “Exotic Species” In: Meeting Notes—U.S. Environmental Protection

Agency (USEPA)/Center for Marine Conservation (CMC) workshop: Volunteer Estuary

Monitoring: Wave of the Future. Astoria, OR: May 19-21, 1999.

Levinton, J.S. 1982. Marine Ecology. Prentice-Hall, Englewood Cliffs, NJ. 526 pp.

Matthews, E. 1998. “Washington State Volunteers Fight Spartina.” The Volunteer Monitor 10(2): 19.

Nordeen, W. 1999. Phytoplankton Cell Count Protocol. University of Maine Cooperative

Extension and Maine Dept. of Marine Resources. April.

Parsons, T.R., M. Takahashi, and B. Hargrave. 1984. Biological Oceanographic Processes. New

York: Pergamon Press. 330 pp.

Pfauth, M., and M. Sytsma. 1998. Key to West Coast Spartina Species Based on Vegetative

Characters. Portland State University Lakes and Reservoirs Program Publication 98-1.

Pimentel, D., L. Lach, R. Zuniga, and D. Morrison. 1999. Environmental and Economic Costs

Associated with Non-Indigenous Species in the United States. Cornell University. Manuscript

available on Internet: http://www.news.cornell.edu/releases/Jan99/species_costs.html.

The Plankton Net—Maine’s Phytoplankton Monitoring Newsletter. Available from University of

Maine Cooperative Extension, 235 Jefferson Street, P.O. Box 309, Waldoboro, ME 04572;

phone: 207-832-0343; fax: 207-832-0377.

References and Further Reading
19-23

Volunteer Estuary Monitoring: A Methods Manual

Unit Three: Biological Measures Chapter 19: Other Living Organisms

Sheehan, L. 2000. Center for Marine Conservation, pers. communication.

Smith, D.L., and K. Johnson. 1996. A Guide to Marine Coastal Plankton and Marine

Invertebrate Larvae. Kendall/Hunt, Dubuque, IA.

Tampa BayWatch and Tampa Bay National Estuary Program. 1998. “Great Bay Scallop Search

Equipment List,” “Field Procedures” (information sheets).

Tomas, C.R. (ed.). 1997. Identifying Marine Phytoplankton. Academic Press, Harcourt Brace &

Co., New York. 858 pp.

U.S. Environmental Protection Agency (USEPA). 1997. Volunteer Stream Monitoring: A

Methods Manual. EPA 841-B-97-003. November. Office of Water, Washington, DC. 211 pp.

Valigra, L. 1999. “Alien Marine Life Eats Locals for Lunch.” Christian Science Monitor Web

site: http://www.csmonitor.com/durable/1999/02/11/p13s1.htm. Feb. 11, 1999.

Washington Sea Grant Program. 1998. Bioinvasions: Breaching Natural Barriers. WSG 98-01.

Web site: http://www.wsg.washington.edu/pubs/bioinvasions/biowarning.html.

Wilcove, David et al. 1998. “Quantifying Threats to Imperiled Species in the United States.”

Bioscience 48(8).

Web sites:

Shellfish

U.S. Food and Drug Administration

1. Center for Food Safety and Applied Nutrition

Fish and Fishery Products Hazards and Controls Guide: 

http://vm.cfsan.fda.gov/~dms/haccp-2.html

Foodborne Pathogenic Microorganisms and Natural Toxins Handbook:

http://vm.cfsan.fda.gov/~mow/chap37.html

Seafood Information and Resources: http://vm.cfsan.fda.gov/seafood1.html

2. Office of Seafood: http://vm.cfsan.fda. gov/~mow/sea-ill.html 

Harmful Algal Blooms

Washington Sea Grant: http://www.wsg.washington.edu/outreach/mas/aquaculture/

algalfacts.html

Non-Indigenous Species

Washington Sea Grant: http://www.wsg.washington.edu/outreach/mas/nis/nis.html

San Francisco Estuary Institute: http://www.sfei.org/invasions.html

Smithsonian Environmental Research Center (SERC): http://www.invasions.si.edu

U.S. Fish and Wildlife Service Invasive Species Program: http://invasives.fws.gov/

Sea Grant Non-Indigenous Species Site: http://www.sgnis.org/

Phytoplankton

Melbourne Parks and Waterways, Biological Surveys: 

http://140.211.62.101/streamwatch/swm13.html
19-24

Volunteer Estuary Monitoring: A Methods Manual

Chapter 19: Other Living Organisms Unit Three: Biological Measures
Appendix A Sample Data Forms
Photos (l to r): R. Ohrel, R. Ohrel, Tillamook Bay National Estuary Project and Battelle Marine Sciences Lab, U.S. Environmental Protection Agency
A-1

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms

The following pages contain examples of data forms that may be useful to volunteer estuary

monitoring programs. Many of the forms are currently being used by volunteer groups throughout

the U.S.

The data forms that can be found on the following pages include:

Page

A-3 Patuxent River Data Collection Form (Alliance for the Chesapeake Bay)

A-5 Citizen Monitoring Program Water Quality Data Sheet (Maine/New Hampshire Sea Grant

Marine Advisory Program and University of Maine Cooperative Extension)

A-7 Citizen Monitoring Data Sheet (source unknown)

A-9 Coastal Watershed Survey Data Sheet (Maine Dept. of Environmental Protection)

A-11 International Coastal Cleanup Data Card (The Ocean Conservancy)

A-13 National Marine Debris Monitoring Program Data Card (The Ocean Conservancy)

A-15 Submerged Aquatic Vegetation Survey Form (U.S. Fish and Wildlife Service)

A-17 SAV Survey Form (source unknown)

A-19 Scallop Search Data Sheet (Tampa BayWatch and the Tampa Bay Estuary Program)

A-21 Shellfish Biotoxin Sample Form (Washington State Department of Health)

A-23 Crustacean Volunteer Survey Form (Portland State University Nonindigenous Species

Monitoring Program)

A-25 European Green Crab Survey Form (Washington Department of Fish and Wildlife)

Appendix A: Sample Data Forms
A-2

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-3

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-4

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-5

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-6

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-7

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-8

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-9

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-10

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-11

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-12

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-13

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-14

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-15

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-16

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-17

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-18

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-19

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-20

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-21

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-22

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-23

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-24

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-25

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
A-26

Volunteer Estuary Monitoring: A Methods Manual

Appendix A: Sample Data Forms
AppendixBResources
Photos (l to r): R. Ohrel, R. Ohrel, Tillamook Bay National Estuary Project and Battelle Marine Sciences Lab, U.S. Environmental Protection Agency
B-1

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

DOCUMENTS NOT REFERENCED IN PREVIOUS CHAPTERS

U.S. EPA. 1992. National Estuary Program Monitoring Guidance. Office of Water, Washington, DC.

EPA 842-B-92-004. Web site: http://www.epa.gov/OWOW/estuaries/guidance/.

U.S. EPA. 1995. Proceedings of the Fourth National Citizen’s Volunteer Monitoring Conference.

EPA Office of Water, Washington, DC. EPA 841-R-94-003. 

U.S. EPA. 1992. Proceedings of the Third National Citizen’s Volunteer Monitoring Conference. EPA

Office of Water, Washington, DC. EPA 841-R-92-004. 

U.S. EPA. Bibliography of Methods for Marine and Estuarine Monitoring (Files 61-80). 

Web site: http://www.epa.gov/owowwtr1/info/PubList/monitoring/docs/list4.html.

U.S. EPA Technical Information Packages (TIPS) Publications List. 

Web site: http://www.epa.gov/clhtml/tips.html.

NEWSLETTERS

Coastlines

National Estuary Program Newsletter

Subscriptions are free. To subscribe, contact:

Coastlines

Urban Harbors Institute

100 Morrissey Blvd.

Boston, MA 02125-3393

Fax: 617-287-5575

E-mail: coastlines@umb.edu

Also available online at www.epa.gov/nep/coastlines/.

NPS News-Notes

EPA Office of Wetlands, Oceans and Watersheds Occasional bulletins dealing with the condition

of the water-related environment, the control of nonpoint sources of water pollution, and the

ecosystem-driven management and restoration of watersheds. 

Subscriptions are free. To subscribe, send name and address to:

NPS News-Notes

c/o Terrene Institute

4 Herbert St.

Alexandria, VA 22305 

Phone: 703-548-5473

Fax: 703-548-6299 

Also available online at http://www.epa.gov/owowwtr1/info/NewsNotes/.

Appendix B: Resources
B-2

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

The Volunteer Monitor

The National Newsletter of Volunteer Water Quality Monitoring 

Published twice yearly. Subscriptions are free. To subscribe, contact:

River Network

The Volunteer Monitor Newsletter

520 SW 6th Ave, Suite 1130

Portland, OR 97204-1535

Phone: 503-241-3506

E-mail: volmon@rivernetwork.org

Also available online at www.epa.gov/OWOW/monitoring/volunteer/vm_index.html.

INTERNET RESOURCES

EPA Volunteer Monitoring ListServe

To subscribe or unsubscribe, send an email to listserver@unixmail.rtpnc.epa.gov. Leave

the subject line blank. In the message type:

subscribe volmonitor lastname firstname or unsubscribe volmonitor lastname firstname

To post a message, address your email to volmonitor@unixmail.rtpnc.epa.gov

The Ocean Conservancy’s Ocean Action Network

You can help protect marine wildlife, and the ecosystems of which they are a part, by 

joining The Ocean Conservancy’s Ocean Action Network (OAN). Subscribers will receive free

OAN Alerts and Updates on issues by e-mail or regular mail: 

Ocean Action Network

1725 DeSales St., NW

Suite 600

Washington, DC 20036

If you prefer to receive and respond to alerts via email, visit The Ocean Conservancy’s Web site 

(www.oceanconservancy.org) and go to “Ocean Action Network”; or send a message, including

your name, postal address and email address to ocean-alert@oceanconservancy.org.

Federal Agency Web Pages:

EPA

EPA homepage: http://www.epa.gov/

EPA Office of Water: http://www.epa.gov/ow/

EPA Office of Wetlands, Oceans & Watersheds: http://www.epa.gov/owow/ 

National Estuary Program: http://www.epa.gov/owow/estuaries/nep.html

Surf Your Watershed: http://www.epa.gov/surf

Volunteer Monitoring: http://www.epa.gov/ OWOW/monitoring/vol.html

Watershed Information Network: http://www.epa.gov/win

NOAA

National Sea Grant Program: http://www.nsgo.seagrant.org/index.html

NERRS Estuary-Net Project: http://inlet.geol.sc.edu/estnet.html

Volunteering for the Coast: http://volunteer.nos.noaa.gov/
B-3

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

Others

U.S. Department of Agriculture, Natural Resources Conservation Service:

http://www.nrcs.usda.gov/

U.S. Fish and Wildlife Service: http://www.fws.gov/

U.S. Forest Service: http://www.fs.fed.us/

U.S. Geological Survey: http://www.usgs.gov/

Links to Environmental Groups:

EnviroLink: http://www.envirolink.org/

Kentucky Water Watch: http://water.nr.state.ky.us/ww/vm.htm

U.S. EPA Office of Water: http://www.epa.gov/owow/estuaries/links.htm#local

FEDERAL AGENCIES AND PROGRAMS

Environmental Protection Agency (EPA)

Office of Wetlands, Oceans, and Watersheds

Volunteer Monitoring (4504T)

1200 Pennsylvania Avenue, NW

Washington, DC 20460

Phone: 202-566-1200

Fax: 202-566-1336

E-mail: OW-General@epamail.epa.gov

National Estuary Program (NEP)

Web site: http://www.epa.gov/owow/estuaries/nep.html

National Oceanic and Atmospheric Administration (NOAA)

U.S. Department of Commerce

14th Street & Constitution Ave., NW

Room 6013

Washington, D.C. 20230

Phone: 202-482-6090

Fax: 202-482-3154

Email: answers@noaa.gov

NOAA Estuarine Reserve Division (NERRS)

1305 East West Highway N/ORM5

Silver Spring, MD 20910

Phone: 301-713-3132

Fax: 301-713-4363 

Web site: http://www.ocrm.nos.noaa.gov/nerr/
B-4

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

Alabama

Mobile Bay Estuary Program

4172 Commanders Drive

Mobile, AL 36615

Phone: 251-431-6409

Fax: 251-431-6450

Web site: http://mobilebaynep.com 

California

Moro Bay Estuary Project

601 Embarcadero, Suite 11

Morro Bay, CA 93442

Phone: 805-772-3834 

Fax: 805-772-4162 

Web site: http://www.mbnep.org

San Francisco Estuary Project

1515 Clay St., Suite 1400

Oakland, CA 94612

Phone: 510-622-2465 

Fax: 510-622-2501 

Web site: http://www.abag.ca.gov/

bayarea/sfep/sfep.html

Santa Monica Bay Restoration Project

320 W. Fourth St., 2nd floor

Los Angeles, CA 90013

Phone: 213-576-6615

Fax: 213-576-6646

Web site: http://www.smbay.org 

Connecticut

Long Island Sound, CT/NY

Long Island Sound Study

64 Stamford Government Center

888 Washington Boulevard

Stamford, CT 06904-2152

Phone: 203-977-1541

Fax: 203-977-1546 

Web site: http://www.epa.gov/

region01/eco/lis

Delaware

Delaware Estuary Program, DE/NJ/PA

Delaware River Basin Commission

P.O. Box 7360

West Trenton, NJ 08628

Phone: 609-883-9500 ext. 217

Fax: 609-883-9522 

Web site: http://www.delep.org/

Center for the Inland Bays

467 Highway One

Lewes, DE 19958

Phone: 302-645-7325

Fax: 302-645-5765 

Web site: http://www.udel.edu/CIB

Florida

Charlotte Harbor Estuary Program

SW Florida Regional Planning Council

4980 Bayline Dr., 4th Fl.

North Fort Myers, FL 33917-3909

Phone: 941-995-1777

Fax: 941-656-7724 

Web site:

http://www.charlotteharbornep.com/

Indian River Lagoon Program

1900 South Harbor City Blvd., #107

Melbourne, FL 32901

Phone: 407-984-4950 

Fax: 407-984-4937 

Web site: http://www.epa.gov/owow/

oceans/lagoon/

Sarasota Bay Project

5333 N. Tamiami Trail, Suite 104

Sarasota, FL 34234

Phone: 941-359-5841

Fax: 941-359-5846 

Web site: http://www.sarasotabay.org

National Estuary Porgram (NEP) Contacts
B-5

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

Tampa Bay Estuary Program

100 8th Avenue, SE, MS I-1/NEP

St. Petersburg, FL 33701

Phone: 727-893-2765

Fax: 727-893-2767 

Web site: http://www.tbep.org/

Louisiana

Barataria-Terrebonne Estuary Program

P.O. Box 2663

Nicholls State University Campus

Thibodaux, LA 70310

Phone: 504-447-0868 or 800-259-0869

Fax: 504-447-0870 

Web site: http://www.mail.btnep.org

Maine

Casco Bay Estuary Project

University of Southern Maine

P.O. Box 9300

49 Exeter Street

Portland, ME 04104-9300

Phone: 207-780-4820

Fax: 207-780-4917

Web site:

http://www.cascobay.usm.maine.edu 

Maryland

Maryland Coastal Bays Program

9609 Stephen Decatur Highway

Berlin, MD 21811

Phone: 410-213-2297

Fax: 410-213-2574 

Web site: http://www.dnr.state.

md.us/coastalbays

Massachusetts

Buzzards Bay Estuary Program

2870 Cranberry Highway

E. Wareham, MA 02538

Marion, MA 02738

Phone: 508-291-3625

Fax: 508-291-3628 

Web site: http://www.buzzardsbay.org/

Massachusetts Bays Program

251 Causeway Street

Suite 900

Boston, MA 02114-2151

Phone: 617-626-1230

Fax: 617-626-1240 

Web site:

http://www.state.ma.us/massbays

New Hampshire

New Hampshire Estuaries

152 Court Street

Portsmouth, NH 03801 

Phone: 603-433-7187

Fax: 603-431-1438

Web site: http://state.nh.us/nhep

New Jersey

Barnegat Bay Estuary Program

P.O. Box 2191

Toms River, NJ 08753

Phone: 732-506-5313

Fax: 732-244-8396

Web site: http://www.bbep.org 

Delaware Estuary Program, DE/NJ/PA

Delaware River Basin Commission

P.O. Box 7360

West Trenton, NJ 08628

Phone: 609-883-9500 ext. 217

Fax: 609-883-9522 

Web site: http://www.delep.org/

New York-New Jersey Harbor Estuary

Program

290 Broadway

24th Floor.

New York, NY 10007

Phone: 212-637-3816

Fax: 212-637-3889

Web site: http://www.harborestuary.org
B-6

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

New York

Long Island Sound Study

64 Stamford Government Center

888 Washington Boulevard

Stamford, CT 06904-2152

Phone: 203-977-1541

Fax: 203-977-1546 

Web site: http://www.epa.gov/

region01/eco/lis

New York-New Jersey Harbor Estuary

Program

290 Broadway

24th Floor.

New York, NY 10007

Phone: 212-637-3816

Fax: 212-637-3889

Web site: http://www.harborestuary.org

Peconic Estuary Program

Department of Health Services

County of Suffolk

Riverhead County Center, 2nd floor

Riverhead, NY 11901

Phone: 631-852-2077

Fax: 631-852-2743 

Web site: http://www.co.suffolk.ny.us/

health/eq/pep.html

North Carolina

Albemarle-Pamlico Sounds NEP

N.C. DENR

P.O. Box 27687

Raleigh, NC 27611-7687

Phone: 919-733-5083 ext. 585

Fax: 919-715-5637 

Web site: http://h2o.enr.state.nc.us/nep/

Oregon

Lower Columbia River Estuary Program

811 SW Naito Parkway

Portland, OR 97204

Phone: 503-226-1565

Fax: 503-226-1580

Web site: http://www.lcrep.org

Tillamook Bay Estuary Program

613 Commercial Avenue

P.O. Box 493

Garibaldi, OR 97118

Phone: 503-322-2222

Fax: 503-322-2261 

Web site:

http://www.co.tillamook.or.us/gov/estuary

/tbnep/nephome.html

Pennsylvania

Delaware Estuary Program

Delaware River Basin Commission

P.O. Box 7360

West Trenton, NJ 08628

Phone: 609-883-9500 ext. 217

Fax: 609-883-9522 

Web site: http://www.delep.org/

Puerto Rico

San Juan Bay NEP

400 Fernandez Juncos Ave., No. 400

San Juan, PR 00901-3299

Phone: 787-725-8162

Fax: 787-725-8164

Web site: http://www.estuariosanjuan.org

Rhode Island

Narragansett Bay Estuary Program

235 Promenade Street

Providence, RI 02908-5767

Phone: 401-222-4700 ext. 7271

Fax: 401-521-4230 

Web site: http://www.nbep.org
B-7

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

Texas

Coastal Bend Bays and Estuaries

Program

Natural Resources Building, Suite 3300

6300 Ocean Drive

Corpus Christi, TX 78412

Phone: 361-980-3425

Fax: 361-980-3437 

Web site: http://tarpon.tamucc.edu

Galveston Bay Estuary Program

711 West Bay Area Boulevard, # 210

Webster, TX 77598

Phone: 281-332-9937

Fax: 281-332-8590 

Web site:

http://gbep.tamug.tamu.edu/gbepix.html

Washington

Lower Columbia River Estuary Program

811 SW Naito Parkway

Portland, OR 97204

Phone: 503-226-1565

Fax: 503-226-1580

Web site: http://www.lcrep.org

Puget Sound Water Quality Action Team

Puget Sound Estuary Program

P.O. Box 40900

Olympia, WA 98504-0900

Phone: 360-407-7300; 

800-54-SOUND (WA only)

Fax: 360-407-7333 

Web site:

http://www.wa.gov/puget_sound

Alabama

Weeks Bay NERR

11300 U.S. Highway 98

Fairhope, AL 36532-5476

Phone: 334-928-9792

Fax: 334-928-1792

Alaska

Kachemak Bay NERR

Homer Office - Reserve Headquarters

202 West Pioneer Avenue

Homer, AK 99603

Phone: 907-235-4799

Fax: 907-235-4794

Anchorage Office - ADF&G

Alaska Department of Fish and Game

Habitat and Restoration Division

333 Raspberry Rd.

Anchorage, AK 99518

Phone: 907-267-2331

Fax: 907-267-2464

California

Elkhorn Slough NERR

1700 Elkhorn Road

Watsonville, CA 95076

Phone: 831-728-2822

Fax: 831-728-1056

National Estuarine Research Reserve System (NERRS) Contacts
B-8

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

Tijuana Estuary Visitor Center

301 Caspian Way

Imperial Beach, CA 91932

Phone: 619-575-3613

Fax: 619-575-6913

San Francisco Bay (Proposed) NERR

Romberg-Tiburon Center

P.O. Box 855

Tiburon, CA 94920

Phone: 415-338-3703

Fax: 415-435-7120

Delaware

Delaware NERR 

818 Kitts Hummock Rd. 

Dover, DE 19901 

Phone: 302-739-3436

Fax: 302-739-3446

Florida

Apalachicola NERR 

Visitor and Education Center 

261 7th Street 

Apalachicola, FL 32320 

Phone: 850-653-8063/2296 

Administrative and Technical Offices 

350 Carroll Street 

Eastpoint, FL 32328 

Phone: 850-670-4783

Fax: 850-670-4324

Rookery Bay NERR

Department of Environmental Protection

300 Tower Road

Naples, FL 34113 

Phone: 941-417-6310

Fax: 941-417-6315

Guana Tolomato Matanzas NERR

PO Box 840069

St. Augustine, FL 32084

Phone: 904-461-4053

Fax: 904-461-4053

Georgia

Sapelo Island NERR

P.O. Box 15

Sapelo Island, GA 31327

Phone: 912-485-2251

Fax: 912-485-2141

Maine

Wells NERR

342 Laudholm Farm Road

Wells, ME 04090

Phone: 207-646-1555

Fax: 207-646-2930

Maryland

Chesapeake Bay NERR - Maryland

Maryland Department of Natural

Resources

Tawes State Office Building, E-2

580 Taylor Avenue

Annapolis, MD 21401

Phone: 410-260-8713

Fax: 410-260-8739
B-9

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

Massachusetts

Waquoit Bay NERR 

P.O. Box 3092 

149 Waquoit Highway 

Waquoit Bay, MA 02536

Phone: 508-457-0495

Fax: 617-727-5537 

Mississippi

Grand Bay NERR

Department of Marine Resources

6005 Bayou Heron Resources

Moss Point, MS 39562

Phone: 228-475-7047

Fax: 228-475-8849

New Hampshire

Great Bay NERR

N.H. Fish and Game Department

Marine Fisheries Department

225 Maine Street

Durham, NH 03824

Phone: 603-868-1095

Fax: 603-868-3305

Sandy Point Discovery Center; GBNERR

89 Depot Road

Stratham, NH 03885

Phone: 603-778-0015

New Jersey

Jacques Cousteau NERR

Institute of Marine and Coastal Sciences

Rutgers University

71 Dudley Road

New Brunswick, NJ 08903-0231

Phone: 732-932-6555

Fax: 732-932-8578

New York

Hudson River NERR

NYS DEC, c/o Bard College Field

Station

Annandale-on-Hudson, NY 12504-5000

Phone: 914-758-7010

Fax: 914-758-7033

St. Lawrence River (Proposed) NERR

317 Washington Street

Watertown, NY 13601

Phone: 315-785-2443

Fax: 315-785-2574

North Carolina

North Carolina NERR 

5001 Masonboro Loop Road

1 Marvin Moss Lane

Wilmington, NC 28409

Phone: 910-962-2470

Fax: 910-962-2410 

North Carolina NERR

c/o Duke University Marine Laboratory

135 Pivers Island Road 

Beaufort, NC 28516 

Phone: 252-728-2170

Fax: 252-728-6273 

Ohio

Old Woman Creek NERR

Department of Natural Resources

2514 Cleveland Road East

Huron, OH 44839

Phone: 419-433-4601

Fax: 419-433-2851
B-10

Volunteer Estuary Monitoring: A Methods Manual

Appendix B: Resources

Oregon

South Slough NERR

P.O. Box 5417 

Charleston, OR 97420

Phone: 541-888-5558

Fax: 541-888-5559

Puerto Rico

Jobos Bay NERR

Department of Natural and

Environmental Resources

Call Box B

Aguirre, PR 00704

Phone: 787-853-4617

Fax: 787-953-4618

Rhode Island

Narragansett Bay NERR 

55 South Reserve Drive 

Prudence Island, RI 02872

Phone: 401-683-6780 (on-site)

Fax: 401-682-1936 

South Carolina

Ace Basin NERR

P.O. Box 12559

Charleston, SC 29412

Phone: 843-762-5062

Fax: 843-762-5001

North Inlet-Winyah Bay NERR 

Baruch Marine Field Laboratory 

University of South Carolina 

P.O. Box 1630 

Georgetown, SC 29442

Phone: 843-546-3623

Fax: 843-546-1632

Virginia

Chesapeake Bay NERR - Virginia

Virginia Institute of Marine Science

P.O. Box 1346

Gloucester Point, Virginia 23062

Phone: 804-684-7135

Fax: 804-684-7120

Washington

Padilla Bay NERR

Department of Ecology 

10441 Bayview-Edison Road 

Mount Vernon, WA 98273-9668

Phone: 360-428-1558 

Fax: 360-428-1491

TDD: 360-757-1549
Appendix C Equipment Suppliers
Photos (l to r): R. Ohrel, R. Ohrel, Tillamook Bay National Estuary Project and Battelle Marine Sciences Lab, U.S. Environmental Protection Agency
C-1

Volunteer Estuary Monitoring: A Methods Manual

Appendix C: Equipment Suppliers

Aquatic Research Instruments

P.O. Box 93

Lemhi, ID 83465

Phone: 800-320-9482; 208-756-8433

Web site: www.aquaticresearch.com

Water samplers, sediment samplers, plankton

samplers, drift nets, calibrated lines, armored

thermometers, BOD bottles.

Ben Meadows Company

190 Etowah Industrial Court

Canton, GA 30114

Phone: 800-241-6401

Web site: www.benmeadows.com

Waders, rubber boots, field water test

equipment, kick nets, dip nets, wash buckets,

forceps.

Carolina Biological Supply Company

2700 York Road

Burlington, NC 27215-3398

Phone: 800-334-5551

Web site: www.carolina.com

Flexible arm magnifiers, hand lenses, forceps,

kick nets, microscopes, reagents, educational

materials, live and mounted specimens for

instruction.

Cole Parmer Instruments, Inc.

625 East Bunker Court

Vernon Hills, IL 60061

Phone: 800-323-4340

Web site: www.coleparmer.com

Lab equipment, field water test equipment,

microscopes.

Chemetrics

Route 28

Calverton, VA 20138

Phone: 800-356-3072

Web site: www.chemetrics.com

Water testing kits for field analysis of

dissolved oxygen, nitrate, nitrite, ammonia,

phosphates, chlorine, sulfur, manganese,

others. 

Consolidated Plastics

8181 Darrow Road

Twinsburg, OH 44087

Phone: 800-362-1000

Web site: www.consolidatedplastics.com

Sampling trays, buckets, Nalgene bottles,

Whirl-paks.

Earth Force

1908 Mt. Vernon Avenue, 2nd Floor

Alexandria, VA 22301

Phone: 703-299-9485

Web site: www.earthforce.org

Earth Force’s GREEN program has low-cost,

self-contained, nontoxic, premeasured water

monitoring kits designed for young people.

Fisher Scientific Company

711 Forbes Ave.

Pittsburgh, PA 15219

Phone: 800-766-7000

Web site: www.fishersci.com

Lab equipment, sample bottles, sieves,

reagents and chemicals, incubators, water test

equipment, Whirl-paks.

Appendix C: Equipment Suppliers

This is a partial list of suppliers from which a volunteer estuary monitoring program might

obtain scientific equipment. This list does not imply endorsement by the U.S. Environmental

Protection Agency.
C-2

Volunteer Estuary Monitoring: A Methods Manual

Appendix C: Equipment Suppliers

Forestry Suppliers, Inc.

P.O. Box 8397

Jackson, MS 39284-8397

Phone: 601-354-3565

Web site: www.forestry-suppliers.com

Secchi disks, transparency tubes, water

sampling equipment, bottom dredges, sediment

samplers, plankton and other nets, fish

measuring boards. Ask for "Environmental

Source" catalogue.

GREEN

See Earth Force

Hach Equipment Company

P.O. Box 389

Loveland, CO 80539-0389

Phone: 800-227-4224

Web site: www.hach.com

Field and lab water testing equipment,

spectrophotometers, incubators, water

sampling kits, fecal coliform sampling

supplies (including presence-absence tests),

reagents, educational materials.

Hydrolab Corporation

8700 Cameron Road

Austin, TX 78754

Phone: 800-949-3766

Web site: www.hydrolab.com

Multi-parameter electronic meters for

physical and chemical parameters.

Idexx Laboratories

One Idexx Drive

Westbrook, ME 04092

Phone: 800-321-0207

Web site: www.idexx.com

Colilert products for bacterial testing.

J. L. Darling Corporation

2614 Pacific Highway East

Tacoma, WA 98424-1017

Phone: 253-922-5000

Web site: www.riteintherain.com

All-weather writing paper.

LaMotte

P.O. Box 329

Chestertown, MD 21620

Phone: 800-344-3100; 410-778-3100 (in

Maryland)

Web site: www.lamotte.com

Water sampling kits, field and lab water testing

equipment, Secchi disks, water samplers,

armored thermometers, calibrated lines,

plankton nets, kick nets, educational materials.

Lawrence Enterprises

See Water Monitoring Equipment & Supply

Micrology Laboratories

206 West Lincoln Avenue

Goshen, IN 46526

Phone: 888-327-9435

Web site: www.micrologylabs.com

Lab equipment and media for bacterial

testing, including Coliscan products (Coliscan

EasyGel and Coliscan MF) and ECA Check.

Millipore Corporation

80 Ashby Road

Bedford, MA 01730

Phone: 800-645-5476

Web site: www.millipore.com

Fecal coliform testing supplies (complete sterile

water filtration system), membrane filters,

sterile pipettes, petri dishes, sterile media, other

water sampling and testing equipment and lab

supplies, incubators, Whirl-paks.

Nalge Nunc International

P.O. Box 20365

Rochester, NY 14602

Phone: 800-625-4327

Web site: www.nalgenunc.com

Fecal coliform testing supplies, membrane

filters, sterile pipettes, petri dishes,

incubators, Whirl-paks.
C-3

Volunteer Estuary Monitoring: A Methods Manual

Appendix C: Equipment Suppliers

National Archives and Records

Administration

Cartographic and Architectural Branch

8601 Adelphi Road

College Park, MD 20740-6001

Phone: 301-713-7040

E-mail: carto@arch2.nara.gov (Note: when

submitting a request via e-mail, be sure to

include a regular mail address.)

Web site:

www.nara.gov/research/ordering/mapordr.html

Photographs, generally from before 1955.

Nichols Net and Twine, Inc.

2200 Highway 111

Granite City, IL 62040

Phone: 618-797-0211; 800-878-6387

Nets of all kinds (dip, kick, insect, larvae,

macroinvertebrates), seines, custom nets.

Ocean Pro Shop

4060 DuPont Parkway 

Townsend, DE 19734

Phone: 302-378-8666

Web site: www.wserv.com/oceanpro/

Nets.

Onset Computer Corporation

P.O. Box 3450

Pocasset, MA 02559-3450

Phone: 800-564-4377; 508-759-9500

Web site: www.onsetcomp.com

Data loggers.

Strategic Diagnostics Inc. (SDI)

111 Pencader Drive 

Newark, DE 19702

Phone: 800-544-8881

Web site: http://www.sdix.com

Immunoassay kits for pesticides, other

contaminants.

Thomas Scientific Company

99 High Hill Road

P.O. Box 99

Swedesboro, NJ 08085

Phone: 856-467-2000; 800-345-2100

Web site: www.thomassci.com

Lab equipment, sample bottles, sieves,

reagents, incubators, water test equipment,

Whirl-paks.

U.S. Department of Agriculture

USDA Consolidated Farm Service Agency

Aerial Photography Field Office

2222 West 2300 South 

Salt Lake City, UT 84119-2020 

Phone: 801-975-3500

Web site: www.fsa.usda.gov

Recent aerial photos.

U.S. Environmental Protection Agency

Maps on Demand Web site:

www.epa.gov/enviro/html/mod/index.html

Internet site that allows users to generate

maps displaying environmental information

for most locations in the U.S. Types of

information that can be mapped include EPAregulated facilities, demographic information,

roads, and waterbodies. Maps of varying

scales can be generated on the site (latitude

and longitude), zip code, county, and basin

levels. Submit your request and email address,

and after a brief wait, you will be able to view

your map on-line or download it.

U.S. Geological Survey

USGS Information Services

Box 25286

Denver Federal Center

Denver, CO 80225

Phone: 888-ASK-USGS

Web site: mapping.usgs.gov/

Topographic maps and aerial photos.
C-4

Volunteer Estuary Monitoring: A Methods Manual

Appendix C: Equipment Suppliers

VWR Scientific

P.O. Box 626

Bridgeport, NJ 08014

Phone: 800-932-5000; 908-757-4045

Web site: www.vwrsp.com

Glassware, labeling tape, sample vials, lab

equipment, incubators, reagents, Whirl-paks.

Wards Natural Science Establishment, Inc.

P.O. Box 92912

Rochester, NY 14692-9012

Phone: 800-962-2660; 716-359-2502

Web site: www.wardsci.com

Alcohol lamps, balances, microscopes, sample

trays, goggles, rubber stoppers, autoclaves,

spectrophotometers, incubators, petri dishes,

sterile pipettes, glassware, educational

materials, live and mounted specimens for

instruction.

Water Monitoring Equipment & Supply

P.O. Box 344

Seal Harbor, ME 04675

Phone: 207-276-5746

Web site: watermonitoringequip.com

Monitoring equipment: transparency tubes,

view scopes, Secchi disks, water samplers,

kick nets, sieve buckets.

Wildlife Supply Company

95 Botsford Place

Buffalo, NY 14216

Phone: 800-799-8301

Web site: www.wildco.com

Kick nets, plankton nets, wash buckets, field

biological sampling equipment, water bottles.

YSI Incorporated

1725 Brannum Lane

Yellow Springs, Ohio 45387

Phone: 937-767-7241

Web site: www.ysi.com

Electronic water quality monitoring meters,

other water quality supplies.
Glossary Glossary and Acronyms
Photos (l to r): R. Ohrel, R. Ohrel, Tillamook Bay National Estuary Project and Battelle Marine Sciences Lab, U.S. Environmental Protection Agency
GA-1

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Abiotic – Pertaining to factors or things that are

separate and independent from living things:

nonliving.

Accuracy – A measure of confidence in a

measurement. As the difference between the

measurement of a parameter and its "true" or

expected value becomes smaller, the

measurement becomes more accurate. 

Acid – Any substance capable of giving up a

proton; a substance that ionizes in solution to

give the positive ion of the solvent; a solution

with a pH measurement less than 7. See also

alkaline.

Acid rain – Precipitation composed of water

particles, sulfuric acid, and/or nitric acid. These

acids are formed from sulfur dioxides from the

smokestacks of coal and oil burning power

plants and from nitrogen oxides emitted by

motor vehicles. This precipitation form can

change the chemistry of healthy soils and

waters, potentially making them unfit to support

life. 

Acidity – A measure of the number of free

hydrogen ions (H+) in a solution that can

chemically react with other substances. Also see

pH.

Acute toxicity – When exposure levels result in

death within 96 hours. Lethal doses differ for

each toxin and species, and are influenced by

the potency and concentration of the toxin. 

Aerobic – Living or occurring only in the

presence of oxygen. 

Algae – Organisms containing chloropyll and

other pigments that permit photosynthesis.

Algae lack true roots, stems, or leaves.

Algaecide – Chemical agent added to water to

destroy algae. 

Algal bloom (algae bloom) – Excessive

growth of aquatic algae resulting from nutrients

such as nitrogen and phosphorus being added to

the environment. Other physical and chemical

conditions can also enable algae to reproduce

rapidly.

Alkaline or basic – A solution with a pH

measurement above 7.0. Alkaline solutions

contain an alkali, which is any base or

hydroxide (OH-) that is soluble in water and

can neutralize acids. Also see base, acid.

Alkalinity – The capacity of water to neutralize

acids, a property imparted by the water's

content of carbonate, bicarbonate, hydroxide,

and on occasion borate, silicate, and phosphate.

It is expressed in milligrams per liter of

equivalent calcium carbonate (mg/l CaCO3). 

Anaerobic – Living or occurring only in the

absence of free oxygen. 

Analyte – Parameter being tested.

Anion – Ion having a negative charge; an atom

with extra electrons. Atoms of non-metals, in

solution, become anions. See conductivity.

Anoxia – A condition when the water becomes

totally depleted of oxygen (below 0.5 mg/l) and

results in the death of any organism that

requires oxygen for survival. The adjective is

anoxic.

Anthropogenic – Coming from human

activities, e.g., human sources of pollutants and

other impacts on natural environments.

Note: The terms contained within this glossary are general definitions and are accurate as they

relate to water analysis. They are for reference only.

Glossary and Acronyms
GA-2

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Atmospheric deposition – The process

whereby air pollutants are deposited on land

and water, sometimes at great distances from

their original sources. Pollution deposited in

snow, fog, or rain is called wet deposition,

while the deposition of pollutants as dry

particles or gases is called dry deposition. Air

pollution can be deposited into waterbodies

either directly from the air or through indirect

deposition, where the pollutants settle on the

land and are then carried into a waterbody by

runoff.

Atomic absorption – Quantitative chemical

method used for the analysis of elemental

constituents. 

Autoclave – An oven-like vessel used for

sterilization of equipment, carrying out

chemical reactions, etc., at high temperature

and pressure.

BMP – See best management practices.

BOD – See biochemical oxygen demand.

Bacteria – Any of numerous unicellular

microorganisms of the class Schizomycetes,

occurring in a wide variety of forms, existing

either as free-living organisms or parasites,

and having a wide range of biochemical, often

pathogenic properties. Some bacteria are

capable of causing human, animal or plant

diseases; others are essential in pollution

control because they breakdown organic

matter in air and water. 

Bacterial examination – The examination of

water and wastewater to determine the

presence, number, and identification of

bacteria. Also called bacterial analysis. 

Ballast water – Water taken on vessels to

keep them stable at sea. Ballast water can

contain aquatic plants, animals, and pathogens

that can be introduced to an estuary when it is

discharged near ports.

Base – Any substance that contains hydroxyl

(OH-) groups and furnishes hydroxide ions in

solution. A molecular or ionic substance

capable of combining with a proton to form a

new substance; a substance that provides a

pair of electrons for a covalent bond with an

acid; a solution with a pH of greater than 7.0.

Also see pH.

Baseline data – Initial data generated by

consistent monitoring of the same sites over

time.

Benthic – Pertaining to the bottom (bed) of a

waterbody.

Best Management Practices (BMPs) –

Pollution control techniques that aim to

reduce pollution from agriculture, timber

harvesting, construction, marinas, stormwater

and other sources. 

Bioassay (biological assay) – A controlled

experiment using a change in biological

activity as a qualitative or quantitative means

of analyzing a biological response to a

pollutant by using viable organisms.

Depending on the test, microorganisms,

planktonic animals, or live fish can be used as

test organisms to determine the effects a toxic

substance has on living organisms.

Biochemical oxygen demand (BOD) – The

amount of oxygen taken up by

microorganisms that decompose organic

waste matter in water. 

Biocides – Chemical agents with the capacity

to kill biological life forms. Bactericides,

insecticides, herbicides, pesticides, etc. are

examples. 

Biodegradability – The susceptibility of a

substance to decomposition by the actions of

microorganisms.
GA-3

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Biological accumulation (bioaccumulation) –

The uptake and storage of chemicals (e.g.,

DDT, PCBs) from the environment by

animals and plants. Uptake can occur through

feeding or direct absorption from water or

sediments. The concentration of a substance

in the tissue of an individual organism.

Biological magnification (also called

bioamplification or bioconcentration) – The

progressive increase in the concentration of

chemical contaminants (e.g., DDT, PCBs,

methyl mercury) from the bottom of the food

chain (e.g., bacteria, phytoplankton,

zooplankton) to the top of the food chain

(e.g., fishing-eating birds such as a

cormorant).

Biomass – The amount of living matter in a

given habitat or the total mass of a particular

species or groups of species in a specified

area. 

Biomonitoring – The use of living organisms

to evaluate the anthropogenic, or humaninduced, impacts on biota. 

Bioturbation – Disturbance of sediment by

animals. 

Bloom – A dramatic increase in the number

and volume of planktonic species as a result

of favorable environmental conditions (e.g.,

temperature, nutrient availability, etc.). See

algal bloom.

Brackish – Having a salinity between that of

fresh and marine water.

Buffer – A substance dissolved in water that

resists changes in pH (minimizes changes in

hydrogen ion concentration). 

Buret – A graduated glass tube used for

measuring and releasing small and precise

amounts of liquid.

Calibration – The checking, adjusting, or

systematic standardizing of the graduations of

a quantitative measuring instrument.

Carcinogen – A substance that causes cancer.

Cation – A positively charged atom or group

of atoms, or a radical which moves to the

negative pole (cathode) during electrolysis.

See conductivity.

Chlorinated hydrocarbons – Compounds

such as DDT and PCBs made of carbon,

hydrogen, and chlorine atoms. Once released

into the environment, these chemicals become

biologically amplified as they move up the

food chain; that is, as minnows eat

zooplankton, larger fish eat minnows, and

seabirds eat the larger fish, the concentration

of these chemicals in tissues is greatly

increased. 

Chlorophyll – A group of green pigments

found in most plants, including

phytoplankton, which are used for

photosynthesis. The chlorophyll a pigment is

generally measured. 

Chronic toxicity – Also referred to as sublethal. Does not result in death (at exposures

of at least 96 hours) but can cause impairment

to aquatic animals, organ damage and failure,

gastro-intestinal damage, and can affect

growth and reproduction. 

Coliform bacteria – Any of several bacilli,

especially of the genera Escherichia, found in

the intestines of animals. Their presence in water

suggests contamination with sewage of feces,

which in turn could mean that disease-causing

bacteria or viruses are present. Fecal coliform

bacteria are used to indicate possible sewage

contamination. Fecal coliform bacteria are not

harmful themselves, but indicate the possible

presence of disease-causing bacteria, viruses, and

protozoans that live in human and animal

digestive systems. In addition to the possible

health risks associated with them, the bacteria
GA-4

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

can also cause cloudy water, unpleasant odors,

and increased biochemical oxygen demand. 

Combined sewer – Sewer system that carries

both sanitary wastes and storm runoff to a

wastewater treatment plant to be treated and

released to a body of water.

Combined sewer overflow (CSO) – If a

wastewater treatment plant does not have the

capacity to treat the increased volume caused

by stormwater runoff, the combined sewer

may discharge untreated sewage and

stormwater directly into a body of water.

Comparability – The extent to which data

from one study can be compared directly to

either past data from the current project or

data from another study. Using standardized

sampling and analytical methods, units of

reporting, and site selection procedures help

ensure comparability.

Completeness – A measure of the number of

samples you must take to be able to use the

information, as compared to the number of

samples you originally planned to take.

Compound – Two or more elements

combined; a substance having properties

different from those of its separate elements. 

Concentrated – Being of full strength or

undiluted. 

Conductivity – A measure of the ability of

water to pass an electrical current. Conductivity

in water is affected by the presence of inorganic

dissolved solids such as chloride, nitrate, sulfate,

and phosphate anions (ions that carry a negative

charge) or sodium, magnesium, calcium, iron,

and aluminum cations (ions that carry a positive

charge). As the concentration of salts in the

water increases, electrical conductivity rises; the

greater the salinity, the higher the conductivity.

Conductivity is also affected by temperature: the

warmer the water, the higher the conductivity.

For this reason, conductivity is extrapolated to a

standard temperature (25°C).

Contamination – A general term signifying

the impairment of water, sediments, plants or

animals by chemicals or bacteria to such a

degree that it creates a hazard to public and/or

environmental health through poisoning,

biomagnification, or the spread of disease. 

DDT – Dichlorodiphenyltrichloroethane. A

chlorinated hydrocarbon widely used as a

pesticide in the United States until its use was

banned in the United States in 1972. Toxic to

humans and wildlife when swallowed or

absorbed through the skin.

DO – See dissolved oxygen.

DQOs – See data quality objectives.

Data Quality Objectives (DQOs) –

Statements that define quantitative and

qualitative information required by the data

users to meet program needs.

Deionized water – Water with all ions

removed.

Denitrification – The process whereby

bacteria convert nitrate to nitrite and then to

nitrogen gas. 

Detection limit – The lowest concentration of

a given pollutant that an analytical method or

equipment can detect and still report as

greater than zero. Generally, as readings

approach the detection limit (i.e., as they go

from higher, easier-to-detect concentrations to

lower, harder-to-detect concentrations), they

become less and less reliable.

Detritus – Small particles of dead and

decomposing organic matter, including twigs,

leaves and other plant and animal wastes.

Digital titrator – A titrator unit having a

counter that displays numbers. As the reagent

is dispensed, the counter changes in

proportion to the amount of reagent used. 
GA-5

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Dilute – To thin out, or having been thinned

out; less than full strength.

Dinoflagellate – A dominant planktonic form

occurring as a microscopic single cell. Often

has two flagella to assist with movement.

Dioxin – A family of some 210 synthetic,

organic chemicals of the chlorinated

hydrocarbon class. Some dioxins are known

to be highly toxic and are thought to increase

the incidence of cancer and birth defects in

humans.

Dissolved oxygen (DO) – Oxygen molecules

that are dissolved in water and available for

living organisms to use for respiration.

Usually expressed in milligrams per liter or

percent of saturation. The concentration of

DO is an important environmental parameter

contributing to water quality. 

Dissolved solids – The total amount of

dissolved material, organic and inorganic,

contained in water or wastewater.

Measurements are expressed as ppm or mg/l.

Distilled water – Water that has been purified

by distillation (boiling the water off as steam

and condensing it back to a liquid, leaving the

impurities behind). Having been boiled, the

water is also sterile.

Dry deposition – See atmospheric deposition.

Ecosystem – A community of species

interacting with each other and with the

physical (nonliving) environment. 

Effluent – A discharge to a body of water

from a defined or point source, generally

consisting of a mixture of waste and water

from industrial or municipal facilities. 

Emergent Plants – Plants rooted under water,

but with their tops extending above the water.

Endpoint – That stage in titration at which an

effect, such as a color change, occurs,

indicating that a desired point in the titration

has been reached.

Endocrine disrupters – chemicals that can

mimic, block, or otherwise disrupt human

hormones. 

Enrichment – The addition of nitrogen,

phosphorous, carbonaceous compounds, or

other nutrients into a waterway that greatly

increase the growth potential for algae and

other aquatic plants. 

Entanglement – To become tangled in or

ensnared. A common cause of death for

marine animals is entanglement by marine

debris. Animals can become caught in

discarded fishing nets, monofilament line, and

other gear, rope, six-pack rings, balloon

ribbons, plastic grocery bags, and other

floating debris.

Enterococci – A group of bacteria found

primarily in the intestinal tract of warmblooded animals. Enterococci are unrelated to

the coliforms; rather, they are a subgroup of

the fecal streptococci group.

Environment – All the factors that act upon

an organism or community of organisms,

including climate, soil, water, chemicals,

radiation, and other living things. 

Environmental Protection Agency (EPA) –

A federal agency, established in 1970,

concerned with air and water quality,

radiation, pesticides, and solid-waste disposal.

It is responsible for enforcing most federal

environmental laws and for administering the

National Estuary Program (NEP).

Epiphyte – A plant that grows upon another

plant, but is not parasitic. On aquatic plants,

excessive epiphytes can decrease the amount

of sunlight reaching the host plant. 
GA-6

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Erosion – The process where wind, water,

ice, and other mechanical and chemical forces

wear away rocks and soil, breaking up

particles and moving them from one place to

another. 

Escherichia coli – A single species within the

fecal coliforms group. Commonly used as

indicator bacteria. Occurs only in the feces of

warm-blooded mammals

Estuary – A semi-enclosed coastal body of

water which has free connection with the

open sea and within which seawater is

measurably diluted with fresh water derived

from land drainage. Estuaries are transition

zones between fresh water and the salt water

of an ocean.

Eutrophic – Highly productive condition,

generally the result of nutrient enrichment in

the water column that may cause algae (e.g.,

phytoplankton) to bloom.

Eutrophication – A condition in an aquatic

ecosystem where high nutrient concentrations

stimulate blooms of algae (e.g.,

phytoplankton). Algal decomposition may

lower dissolved oxygen concentrations.

Although eutrophication is a natural process

in the aging of lakes and some estuaries, it

can be accelerated by both point and nonpoint

sources of nutrients.

Fecal coliforms – See coliform bacteria.

Filter feeders – Animals (e.g., clams and

oysters) that feed by filtering out of the water

column small food items such as detritus,

phytoplankton, and zooplankton.

Filtration – The process of separating solids

from a liquid by means of a porous substance

(filter) through which only the liquid can pass.

Fish Consumption Advisory – An advisory

issued by government agencies and used to

reduce human health risks associated with

exposure to chemical contaminants (e.g.,

PCBs, DDT, mercury) found in fish and

shellfish. Advisories may recommend bans

and restricted consumption of specific species

in specific geographical areas of an estuary.

Fixed sample –A sample that has been

rendered chemically stable or unalterable,

meaning that atmospheric oxygen will no

longer affect the test result. 

Flushing rate – The time it takes for all the

water in an estuary to be moved out to sea.

Flushing rates vary from days to weeks. 

Food chain – A sequence of organisms in an

ecological community, each of which is food

for the next higher organism, from the

primary producer to the top consumer. 

Food web – A complex system of energy and

food transfer between organisms in an

ecosystem. Refers to the way that organic

matter is transferred from the primary

producers (plants) to primary consumers

(herbivores), and on up to higher feeding

(trophic) levels.

Formalin – A 40% solution of Formaldehyde

(CH2O), which is a preservative, an irritant,

and a probable carcinogen. Formalin is used

to preserve organisms for later observation.

Fresh water – Water that is not salty. Fresh

water enters estuaries from rivers, streams and

through precipitation (rain, snow).

Habitat – The place where a population or

community (e.g., microorganisms, plants,

animals) lives and its surroundings, both

living and nonliving. 

Habitat disruption – Destruction or

alteration of a habitat by cutting across or

establishing barriers to migration routes or

destroying breeding areas or food sources.

Loss of habitat is the primary cause of loss of

biodiversity. 
GA-7

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Heavy metals – A general term given to the

ions of metallic elements such as mercury,

copper, zinc, chromium, and aluminum.

Herbicide – A pesticide designed to kill

specific plants.

Hydrocarbon – A chemical compound

containing only hydrogen and carbon.

Hypoxia – A condition where very low

concentrations of dissolved oxygen are in the

water column. When the level of dissolved

oxygen falls below 3 mg/l, water is

considered hypoxic. At this level, many

species will move elsewhere and immobile

species may die.

Indicator – 1) A compound that changes

color under a particular condition or over a

particular range of conditions. 2) An organism

whose presence suggests the presence of other

organisms. See coliform bacteria. 3) A

measurement of environmental conditions or

trends in environmental quality which can be

used to evaluate resource protection programs

and assess the general sate of the

environment.

Ingestion – To eat. Some animals die from

marine debris when they mistakenly ingest

humanmade materials. By consuming these

materials, damage can be caused to the

animals’ digestive systems, or animals may

stop eating because their stomachs are full.

Because the debris in their stomachs offers no

nutritional value, creatures eventually starve

to death.

Inorganic – Being or composed of matter that

is not organic. 

Invertebrates – Animals that lack a spinal

column or backbone. Includes molluscs (e.g.,

clams and oysters), crustaceans (e.g., crabs

and shrimp), insects, starfish, jellyfish,

sponges, and many types of worms that live

in the benthos. 

Land use – The way land is developed and

used in terms of the kinds of anthropogenic

(human) activities that occur (e.g., agriculture,

residential areas, industrial areas).

Larva, larvae – An immature form of an

organism that will undergo metamorphosis to

become a juvenile and then an adult.

mg/l – See milligrams per liter.

MPN – See most probable number.

Macro – A prefix meaning large. Usually

refers to organisms large enough to be seen

with the un-aided eye.

Macroinvertebrates – Organisms that are

large (macro) enough to be seen with the

naked eye and lack a backbone (invertebrate). 

Marsh or salt marsh – A protected intertidal

wetland where fresh water and salt water

meet. Characterized by plants such as salt hay,

black rush, and smooth cordgrass. 

Mean (Average) – Using a set of n numbers,

the sum of the numbers divided by n.

Measurement range – The range of reliable

measurements of an instrument or measuring

device. 

Membrane filtration – An analytical method

commonly used to identify coliforms in water.

A measured amount of water is passed

through a membrane filter, trapping bacteria

on its surface. The filter is then placed on a

pad that has been saturated with a specific

medium designed to permit the growth of the

organism or organisms being sought. The

filter is incubated, and the bacterial colonies

which have grown on the filter surface are

counted to determine the number of bacteria

in the water sample. 
GA-8

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Meniscus – The curved upper surface of a

non-turbulent liquid in a container; it is

concave (curves upward) if it wets the

container walls, and convex (curves

downward) if it does not. For accurate

measurements, readings should be taken at the

flat center of the meniscus. The curve of the

meniscus is due to surface tension.

Metadata – “Data about data.” Information

that helps characterize the data that volunteers

collect. Metadata answer who, what, when,

where, why, and how about every facet of the

data being documented. This information

helps others understand exactly how the data

was obtained.

Metals, toxic – Some fifty of the eighty

elemental metals used in industry, many of

which (e.g., cadmium, lead, mercury and zinc)

are toxic to humans and are primarily absorbed

into the body by inhalation or ingestion. 

Micro – A prefix meaning one-millionth of a

unit. 

Microorganisms – Organisms (microbes)

observable only through a microscope; larger,

visible types are called macroorganisms. 

Milligrams per liter (mg/l) – A weight per

volume designation used in water and

wastewater analysis. Equivalent to parts per

million (1 ppm = 1 mg/l). 

Molecule – The simplest structural unit of a

substance that retains the properties of the

substance and is composed of one or more

atoms. 

Most probable number (MPN) – An

analytical method used to detect the presence

of coliforms in a water sample and estimate

their numbers.

NEP – See National Estuary Program.

NERRS – See National Estuarine Research

Reserve System.

National Estuarine Research Reserve

System (NERRS) – A federal program

administered by the National Oceanic and

Atmospheric Administration (NOAA). NERR

sites monitor the effects of natural and human

activities on estuaries to help identify methods

to manage and protect coastal areas.

National Estuary Program – A federal

program administered by the EPA that targets

a broad range of issues and engages local

communities in the process. Each NEP is

made up of representatives from federal, state,

and local government agencies and members

of the community working together to identify

problems in the estuary, develop specific

actions to address those problems, and create

and implement a formal management plan to

restore and protect the estuary. 

Nephelometer – An instrument that measures

scattered light in a liquid. 

Nephelometric turbidity unit (NTU) – A

standard unit of turbidity measurement.

Neutral – On the pH scale, neither acid nor

alkaline. Pure water is neutral, and has a pH

of 7.0.

Nitrates – One form of nitrogen that plants

can use for growth.

Nitrification – The process whereby some

bacteria transform ammonium into nitrite and

then to nitrate. 

Nitrogen – An essential nutrient for plant and

animal development. Too much of this

nutrient can cause accelerated plant growth,

algae blooms, and increase the amount of

material available for decomposition (which

lowers dissolved oxygen).

Non-Indigenous Species (NIS) – Species that

migrate or are carried by animals and humans

into ecosystems outside their normal range of

occurrence. These “ alien invaders” are known

by many names, including alien, non-native,
GA-9

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

introduced, nuisance, invasive, and exotic

species. Some of these organisms can wreak

havoc on any ecosystem—including

estuaries—once they become established.

Nonpoint source pollution – Pollution that

enters water from sources that cannot be

traced to a single point. Generally initiated by

stormwater runoff from agricultural, urban,

forestry, marina, construction, and other land

uses.

Nonsettleable matter – Suspended matter

that neither settles nor floats to the surface of

water in a period of one hour. 

Nutrient – Any of a necessary complement of

organic or inorganic elements or compounds

that are considered essential to the biological

growth of an organism.

Nutrient loading – Delivery of nutrients to a

waterbody. An excess of nutrient loads beyond

normal levels may lead to a phytoplankton

population increase. See algal blooms.

Organic matter – Composed of chemical

compounds based on carbon chains or rings,

and also containing hydrogen with or without

oxygen, nitrogen, or other compounds. 

Orthophosphate – An acid or salt containing

phosphorus as PO4, such as K3PO4

(potassium phosphate).

Outliers – Findings that differ radically from

past data or other data from similar sites.

Overturn – A process characterized by a

breakdown in the stratification of a waterbody

(e.g., by changing seasons or storms) and the

subsequent mixing of deep water with surface

water. 

PAHs – See polycyclic aromatic

hydrocarbons.

ppm – See parts per million.

ppt – See parts per thousand.

PCBs – See polychlorinated biphenyls.

Parts per million (ppm) – The unit

commonly used to represent the degree of

pollutant concentration where the

concentrations are small. Larger

concentrations are given in percentages.

Equivalent to milligrams per liter (mg/l)

where 1 ppm = 1 mg/l; in water, ppm

represents a weight/volume ratio. 

Patchiness – Refers to the uneven spatial

distribution of organisms. Plankton tend to

exhibit patchiness in the water column,

grouping together in “ patches.”

Pathogen – An organism (such as a

bacterium or virus) that can cause a disease.

Percent saturation – Amount of oxygen in

the water compared to the maximum it could

hold at that temperature. 

pH – A measure of the alkalinity or acidity of

a substance. Also defined as “ the negative

logarithm of the hydrogen ion concentration 

(-log10[H+])” where H+ is the hydrogen ion

concentration in moles per liter. The pH of a

substance is neutral at 7.0, acidic below 7.0,

and alkaline above 7.0.

Phosphorus – An essential nutrient for plant

and animal development. However, too much

of this nutrient can cause accelerated plant

growth, algae blooms, and increase the amount

of material available for decomposition (which

lowers dissolved oxygen).

Photosynthesis – Process by which chlorophyllcontaining cells in green plants convert incident

light to chemical energy and synthesize organic

compounds from inorganic compounds

(including carbon dioxide and water).

Phytoplankton – Microscopic plants that are

common components of our natural waters.

These plants are microalgae, and contain an
GA-10

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

assortment of pigments in their cells. They are

represented by single cell or colonial forms

that are the primary food and oxygen

producers within freshwater, estuarine, and

marine habitats. Through the process of

photosynthesis they utilize the sun’s energy to

reproduce and provide the food resources

necessary to support other organisms.

Plankton – A broad group of aquatic

microorganisms that form the basis of the

food chain. They are incapable of moving

against water currents. Included in this group

are bacterioplankton (bacteria), phytoplankton

(plants), and zooplankton (animals). 

Point source pollution – Pollution discharged

into a waterbody from any discrete pipe or

other conveyance. Easier to identify, and often

less expensive to cleanup than nonpoint

sources of water pollution.

Polychlorinated biphenyls (PCBs) – Group

of more than two hundred chlorinated toxic

hydrocarbon compounds that can be

amplified, that is, spread and increased, in

food chains and webs. 

Polycyclic aromatic hydrocarbons (PAHs) –

A class of chemical compounds composed of

fused six-carbon rings. PAHs are commonly

found in petroleum oils (e.g., gasoline and

fuel oils) and are emitted from various

combustion processes (e.g., automobile

exhausts, coal-burning operations).

Precipitant – A chemical or chemicals that

cause a precipitate to form when added to a

solution. 

Precipitate – The discrete particles of

material separate from a liquid solution. 

Precision – The degree of agreement among

repeated measurements of the same parameter

on the same sample or on separate samples

collected as close as possible in time and

place. It tells you how consistent and

reproducible your methods are by showing

you how close your measurements are to each

other. Typically, precision is monitored

through the use of replicate samples or

measurements. 

Presence-absence test (P-A test) – A method

commonly used to determine whether the

target organism or organisms (for example,

total coliforms or E. coli) are present in a

water sample or not.

Protozoans – Any of a number of one-celled,

usually microscopic animals, belonging to the

lowest division of the animal kingdom.

QA/QC – See quality assurance/quality

control.

Quality assurance project plan (QAPP) –

A written plan which details monitoring

objectives, scope of the program, methods,

procedures (field and lab), and the activities

necessary to meet stated data quality

objectives.

Quality assurance/quality control (QA/QC) –

The total integrated program for assuring

reliability of monitoring and measurement

data.

Reagent – A chemical substance used to cause

a reaction for the purpose of chemical analysis. 

Replicate samples – Two or more samples

taken from the same place at the same time.

Representativeness – The extent to which

measurements actually depict the true

environmental condition or population you are

evaluating.

Risk management – To control issues that

can cause physical or financial injury or

damage. Risk management programs include

plans to reduce risk and liability by stressing

safety with volunteers, purchasing insurance,

and using waivers.
GA-11

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Runoff – Water from rain, melted snow or

agricultural or landscape irrigation that flows

over the land surface. 

SAV – See submerged aquatic vegetation.

Salinity – A measure of the amount of salts

dissolved in water. Generally reported as

“ parts per thousand” (i.e., grams of salt per

1,000 grams of water) and abbreviated as

“ppt” or ‰. Estuaries vary in salinity from 0

ppt to 34 ppt depending on the relative input

of fresh and marine water. 

Salt – Any compound formed by combination

of any negative ion (except hydroxide) with

any positive ion (except hydrogen or

hydronium); the precipitate produced as the

result of neutralization of an acid with a base.

Seagrass – In marine environments, rooted

vascular plants that generally grow up to the

water surface but not above it. See submerged

aquatic vegetation. 

Secchi depth – The depth beneath the water’s

surface at which a Secchi disk can no longer

be seen. 

Secchi disk – A round, eight-inch (20 cm),

weighted, usually black and white disk that is

lowered by rope into the water. Secchi disks

are used to measure transparency, which is an

integrated measure of light scattering and

absorption. 

Sediment – Mud, sand, silt, clay, shell debris,

and other particles that settle on the bottom of

waterways. 

Sedimentation – The deposition of suspended

matter carried by water, wastewater, or other

liquids, by gravity. It is usually accomplished

by reducing the velocity of the liquid below

the point at which it can transport the

suspended material. Also called settling. 

Sensitivity – The capability of a method or

instrument to discriminate between

measurement responses. The more sensitive a

method is, the better able it is to detect lower

concentrations of a variable. Sensitivity is

related to detection limit, which is the lowest

concentration of a given pollutant your

methods or equipment can detect and report

as greater than zero. 

Settleable solids – Particles of debris and fine

matter heavy enough to settle out of water. 

Sewage – The total of organic waste and

wastewater generated by residential and

commercial establishments. 

Sewage, combined – Wastewater containing

both sanitary sewage and surface or

stormwater with or without industrial wastes. 

Sewage, industrial – Sewage in which

industrial wastes predominate. 

Sewage, raw – Sewage prior to receiving any

treatment. 

Shellfish – Any aquatic animal with a shell,

as the clam, oyster, mussel, and scallop. The

organism feeds by filtering water through its

gills and removing food materials.

Solution – A liquid (solvent) that contains a

dissolved substance (solute). 

Species, alien, invasive or introduced – See

non-indigenous species.

Species – 1) A single, distinct kind of

organism, having certain distinguishing

characteristics. Organisms forming a natural

population that transmit specific

characteristics from parent to offspring. 2)

Chemical forms. For example, nitrogen comes

in many different chemical forms, including

nitrite (NO2

-) and nitrate (NO3-).
GA-12

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Specific gravity – Also called relative

density. The ratio of the density of a substance

to the density of some reference substance.

Hydrometers use this principle to determine

salinity of a water sample, compared to fresh

water.

Standard (or standardized solution) – A

solution containing a known, precise

concentration of an element or chemical

compound, often used to calibrate water

quality monitoring equipment. 

Standard deviation – A statistical measure of

the dispersion of data.

STORET – (Store-Retrieve) A data storage

system operated by EPA that stores raw data

on water quality, bacteriological, biological,

and other parameters. Using the data, one can

create reports for a given site and compare

one watershed with another. 

Stratification – The formation, accumulation,

or deposition of material in layers, such as

layers of fresh water overlying salt water in

estuaries.

Submerged Aquatic Vegetation (SAV) –

Aquatic plants that generally include rooted

vascular plants that grow up to the water

surface but not above it (although a few

species have flowers or tufts that may stick a

few centimeters above the surface). The

definition of SAV usually excludes algae,

floating plants, and plants that grow above the

water surface. Sometimes called seagrass in

marine environments.

Suspended Sediments – Particles of soil,

sediment, living material, or detritus

suspended in the water column.

Temperature – A measure of the hotness or

coldness of anything, as usually determined

by a thermometer. Temperature is a

determining factor for biological and chemical

processes. 

Tide – The alternating rise and fall of the

ocean and estuary surface, caused by the

gravitational pull of the sun and the moon

upon the earth. 

Titration – A method of analyzing the

composition of a solution by adding known

amounts of a standardized solution until a

given reaction (color change, precipitation, or

conductivity change) is produced. 

Titrator – Instrument that forcefully expels a

reagent by using a manual or mechanical

plunger. The amount of reagent used is

calculated by subtracting the original volume

in the titrator from the volume left after the

endpoint has been reached. 

Total coliforms – A group of closely related

bacterial genera that all share a useful

diagnostic feature: the ability to metabolize

(ferment) the sugar lactose, producing both

acid and gas as byproducts. 

Toxic waste – Discarded material that is

capable of causing serious injury, illness, or

death. Toxins can be poisonous, carcinogenic,

or otherwise harmful to living things.

Transparency – An integrated measure of

light scattering and absorption. Secchi disks

are commonly used to measure transparency

of water.

Turbidimeter – An instrument for measuring

turbidity in which a standard suspension is

used for reference. 

Turbidity – A measure of how clear the water

is; how much the suspended material in water

results in the scattering and absorption of light

rays. An analytical quantity is usually

reported in turbidity units and determined by

measurements of light diffraction. Material

that can increase the turbidity (reduce clarity

of water) are suspended clay, silt, sand, algae,

plankton, microbes, and other substances. 
GA-13

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms

Volume – The space occupied in three

dimensions. 

Voucher collection – A preserved archive of

organisms that have been collected and

identified. In addition to preserved specimens,

the collection may involve photography or

microscopy.

Water clarity – Measurement of how far an

observer can see through water. The greater

the water clarity, the further you can see

through the water.

Water column – The water between the

surface and the bottom of a river, lake,

estuary, or ocean.

Water quality parameters – Any of the

measurable qualities or contents of water.

Includes temperature, salinity, turbidity,

nutrients, dissolved oxygen, and others.

Watershed – The entire area of land whose

runoff of water, sediments, and dissolved

materials (e.g., nutrients, contaminants) drain

into a river, lake, estuary, or ocean. 

Wet deposition – See atmospheric deposition.

Wetlands – Lands that are often transitional

areas between terrestrial and aquatic systems,

with enough surface or groundwater to

support a complex chain of life, including

microorganisms, vegetation, reptiles, fish, and

amphibians. Wetlands usually border larger

bodies of water such as rivers, lakes, bays,

estuaries and the open sea, and may serve as

breeding grounds for many species. Examples

include swamps, marshes, and bogs.

Whirl-pak bag – Sterilized, clear

polyethylene bags used to collect water

samples for analysis. 

Wrack – Line of seaweed and organic

material that can be seen when the high tide

recedes. 

Zooplankton – Aquatic microorganisms that

are free floating or capable of minimal

movement. Zooplankton feed primarily on

phytoplankton and bacteria, are can be either

adult microorganisms, or larval forms of fish

or shellfish.
GA-14

Volunteer Estuary Monitoring: A Methods Manual

Glossary and Acronyms
Index
Photos (l to r): The Ocean Conservancy, L. Monk, The Ocean Conservancy, K. Register
I-1

Volunteer Estuary Monitoring: A Methods Manual

Index

A

accuracy, 3-5, 4-10, 5-6, 5-7, 5-9—5-11, 5-18,

5-22, 6-3, 9-6, 9-9, 9-11, 11-4, 11-7—11-9,

13-3, 14-5, 17-2, 17-10

accurate, 2-9, 6-3, 6-5, 7-12, 8-2, 9-4, 9-13,

10-7, 10-8, 11-3, 11-4, 11-6, 11-10, 14-7,

15-4, 15-6, 16-11, 17-11, 19-5, 19-15

acid (acidic), 9-13, 11-2, 11-6—11-8

aerobic, 17-3

algae, 5-14, 7-6, 7-13, 10-2, 10-3, 11-3, 12-6,

15-2, 17-12, 18-1, 18-3, 18-8, 18-9, 

19-7—19-9

algal blooms, 2-6, 2-8, 7-2, 8-8, 8-16, 10-2,

10-6, 11-2, 17-8, 18-3, 18-4, 19-9, 19-10

harmful algal blooms (HAB), 12-2, 12-6,

19-9, 19-12, 19-14

alkalinity, Ch. 11, 2-6, 5-12

ammonium, 10-6

anaerobic, 17-3

analyte, 5-10, 5-11

anions, 14-3

anoxia, 9-3, 9-4

anoxic, 10-3, 10-6

anthropogenic sources, 12-3

atmospheric deposition, 2-5, 10-1—10-3, 

10-11, 10-12, 12-2, 12-4, 12-8

autoclave, 7-8, 7-15, 17-8, 17-11, 17-12

B

bacteria, Ch. 17, 2-6, 2-7, 2-10, 2-13, 5-10, 

5-12, 6-2, 6-6, 7-5, 7-8, 7-13—7-15, 8-12,

9-2, 10-2, 10-3, 10-6, 15-3, 19-4, 19-7, 

19-9

blooms, 10-6

culture disposal, 17-12

source tracking, 17-4

bar graph, 8-11, 8-12

base, 11-8

basic, 11-2

benthic, 2-7, 15-3, 17-3, 19-3

bias, 5-6

bioassay (biological assay), 12-7

biochemical oxygen demand (BOD), Ch. 9, 

2-6, 6-3, 7-16

biological accumulation (bioaccumulation),

12-3, 12-4

biological amplification (bioamplification),

12-3, 12-4

brown tide, 10-3

buffer, 11-4, 11-6, 17-16

C

cadmium, 12-4, 19-4

calibrate (calibration), 5-2, 5-4, 5-21, 5-22, 

6-3, 7-9, 7-17, 9-7, 9-10, 10-7, 10-8, 11-6,

11-9, 14-2, 14-4, 14-6, 15-7, 15-8

calibration blank, 5-11, 5-12

calibration standards, 5-11, 5-12, 11-4

cations, 14-3

chlorinity, 14-3, 14-4

chlorophyll, 6-2, 10-10, 19-16

chromium, 12-4

color comparator, 6-3, 11-3

colorimeter, 10-7, 10-8, 11-3—11-5, 14-3

colorimetric method, 11-3—11-5

comparability, 5-9, 5-18, 5-19, 5-22

completeness, 5-8, 5-18, 5-19, 5-22

conductivity, 2-6, 5-12, 6-3, 14-3—14-6

copper, 12-4

crab jubilee, 6-7

D

data 

analysis, 3-8, 8-2

forms/cards/sheets, 3-4, 3-5, 4-4, 4-5, 

4-10, 5-19, 5-22, 7-2, 7-9, 7-13, 7-16,

7-17, 8-2—8-6, 9-10, 10-10, 10-12, 

11-6, 11-9, 11-10, 13-4, 14-6, 14-7, 

15-7—15-9, 16-6—16-12, 17-10, 

18-12, 18-13, 19-12, 19-19

Index
I-2

Volunteer Estuary Monitoring: A Methods Manual

Index

interpretation, 4-4, 7-2, 7-10, 8-2, 8-7, 10-8

loggers, 13-3

management, 3-2, 3-4, 3-8, 5-15, 5-21, 

8-2—8-5

presentation, 8-2, 8-10

quality objectives, 3-2, 5-14, 5-18, 5-19, 

5-22, 9-7, 10-8, 11-5, 11-7, 13-3, 14-5, 

15-4, 19-12, 19-19

user(s), 3-2, 3-5, 4-4, 4-12, 5-2, 5-3, 5-9,

5-13—5-16, 5-18—5-20, 5-22, 7-17, 8-

2, 8-8, 8-10, 8-16, 17-13, 19-19

DDT, 12-1—12-3, 12-5

deionized water, 5-10, 5-11, 7-9, 7-15, 11-4,

11-6, 11-8, 14-6

demineralized water, 11-4

denitrification, 10-6

density, 14-3, 14-4

detection limit, 5-9, 8-8, 8-9

detritus, 10-4, 15-3, 17-3, 18-2, 19-4

digital titrator, 11-7, 11-8

dinoflagellate(s), 7-13, 10-3, 19-7—19-9, 

19-17

dioxin, 12-6

dissolved oxygen (DO), Ch. 9, 2-6, 

2-8—2-11, 5-12, 5-19, 6-2, 6-3, 6-5, 6-6,

7-12—7-17, 8-12, 8-13, 10-3, 10-6, 13-2,

13-3, 14-2, 15-2, 15-3, 18-1, 18-4

saturation, 9-12

distilled water, 5-10, 6-3, 7-9, 11-9, 14-6, 

15-9

dry deposition, 10-11

E

eelgrass, 18-4—18-6, 18-8, 18-12

wasting disease, 18-5

effluent, 7-14, 17-12, 17-7, 17-9

endocrine disrupter, 12-5

endpoint, 9-6, 9-10, 11-7, 11-9, 14-5

entangle(ment), 16-3, 16-8, 16-10, 16-12

enterococci, 17-1, 17-2, 17-5, 17-6, 

17-12—17-14

EPA—see U.S. Environmental Protection

Agency

epiphytes, 18-3

Escherichia coli, 17-1, 17-2, 17-5, 17-6, 

17-11—17-14

eutrophic, 9-14

eutrophication, 2-6, 10-2

external check, 5-11, 5-12

external field duplicate, 5-11, 5-12

F

fecal coliform, 6-2, 17-1—17-6, 17-8, 

17-10—17-13, 17-16, 19-4, 19-5

fertilizers, 6-6, 10-2, 10-3, 10-5, 10-6, 10-11,

12-4

field blank, 5-10—5-12

field replicate, 5-10, 5-12

fish kill, 2-8, 6-7, 7-13, 10-3

food chain, 2-10, 12-4—12-6

food web, 2-7, 17-3, 19-2, 19-8, 19-17

fundraising, 2-13, 3-7—3-10

G

Geographic Information System(s) (GIS), 8-14

global positioning system (GPS), 7-3, 7-4, 

7-9, 7-11, 7-12, 18-10—18-12

graphics, 3-13, 3-14, 8-3, 8-10—14, 8-17

groundtruth(ing), 18-7, 18-9, 18-10

H

harmful algal blooms (HAB)—see algal

blooms

hydrometer, 5-19, 14-4—14-6

hypoxia, 9-2—9-4

hypoxic, 10-3, 19-9

I

indicator, 17-2, 17-4—17-6, 17-10—17-14,

19-1—19-4

ingestion, 16-3

insurance, 3-6, 3-7

internal check, 5-10, 5-12

invertebrate, 2-12, 12-7, 18-4, 19-2
I-3

Volunteer Estuary Monitoring: A Methods Manual

Index

K

Kemmerer (water sampler), 7-17, 9-4, 9-7,

10-5, 19-11, 19-15

L

lab replicate, 5-10, 5-12

land use, 2-5, 2-13, 3-3, 5-9, 7-12, 8-8, 8-14,

15-2, 16-4, 18-4

associated pollutants, 2-6

lead, 12-4

liability, 3-6, 4-13

line graph, 8-13

M

macroinvertebrate, 2-11, 2-12, 6-2, 

19-1—19-3

manatee grass, 18-6

maps, 18-7, 18-9—18-12

topographic, 18-14

bathymetric, 18-14

marine debris, Ch. 16, 2-7, 2-10, 8-12

marker buoy method, 7-11

MARPOL, 16-3

maximum turbidity, 2-10

mean, 5-5, 5-6, 8-6, 8-8

measurement range, 5-9

median, 8-6

membrane filtration (MF), 17-10—17-17

meniscus, 9-9, 14-6

mercury, 12-3, 12-4, 12-8, 13-317-2, 19-4

metadata, 5-15

metals, 2-6, 2-7, 6-2, 11-2, 12-2, 12-6, 12-7,

19-4

most probable number (MPN), 17-10—17-12,

17-14

N

National Estuarine Research Reserve System

(NERRS), 2-12, 3-11

National Estuary Program (NEP), 2-12, 3-7,

3-11

National Oceanic and Atmospheric

Administration (NOAA), 2-11, 2-12, 3-3,

3-7, 3-11, 7-15

negative plate, 5-10, 5-12

neutral, 11-2

nitrate, 10-5, 10-6, 14-3, 14-4, 17-3

nitrification, 10-6

nitrite, 9-8, 10-5, 10-6, 17-3

nitrogen, 2-8, 7-15 10-1, 10-2, 10-4—10-8,

10-11, 10-12, 18-3

fixation, 10-2, 10-6

non-indigenous species (NIS), 2-10, 3-5, 

16-4, 18-4, 19-1, 19-2, 19-16—19-20

nonpoint source (NPS), 2-5, 2-9, 2-10, 3-14,

6-5, 10-2, 10-5, 17-14

nutrient(s), Ch. 10, 2-3, 2-6, 2-8—2-11, 5-12,

6-2, 6-5, 6-6, 7-14, 8-9, 8-10, 9-2, 11-2,

12-4, 13-2, 17-2, 17-3, 17-17, 18-1—18-5,

19-2, 19-9, 19-10

“pillows,” 9-15

O

outlier, 8-5, 8-6

overturn, 9-3

oxygen, Ch. 9, 6-5, 6-7, 7-6, 10-2, 10-6, 10-7,

10-10, 14-3, 15-3, 18-2, 18-4, 19-7—19-9

P

PAHs (polycyclic aromatic hydrocarbons), 

12-1—12-3, 12-5, 12-6, 19-4

partnership, 3-11, 3-12

pathogens, 2-10, 14-2, 17-1, 17-2, 17-4, 19-2,

19-4, 19-16

PCBs (polychlorinated biphenyls), 

12-1—12-3, 12-5, 12-6, 17-2, 19-4

percent saturation, 2-11, 9-7, 9-8, 9-12, 14-3

performance based measurement system

(PBMS), 5-20

pesticides, 2-6, 6-2, 6-6, 12-5, 15-3, 17-2, 

19-4

Pfiesteria, 10-3

pH, Ch. 11, 2-6, 2-9, 2-11, 5-9, 5-12, 5-19, 

6-2, 6-3, 8-12, 13-3, 14-3, 17-15
I-4

Volunteer Estuary Monitoring: A Methods Manual

Index

phosphate, 7-15, 10-6, 14-3

phosphorus, 7-15, 10-1, 10-2, 10-4—10-8, 

10-10, 18-3

phytoplankton, Ch. 19, 6-2, 7-13, 7-14, 9-2,

10-3, 10-8—10-10, 12-3, 13-2, 15-1, 15-5,

18-3, 18-4

blooms, 7-14, 10-6, 10-7, 18-2, 18-3, 19-2

pie chart, 8-12, 8-13

plankton, 2-10, 2-11, 7-13, 9-3, 15-2, 

19-7—19-9, 19-11, 19-13—19-15

net, 19-11—19-15

point source(s), 2-5, 2-9, 2-10, 6-5, 6-6, 10-2,

10-5, 10-11

positive plates, 5-10, 5-12

precise, 4-2, 5-6, 6-3, 9-10, 10-7, 11-7, 15-6

precision, 4-10, 5-4—5-6, 5-10, 5-11, 5-18, 

5-22, 17-18, 19-11

presence-absence (P-A) test, 17-10, 17-12,

17-14

press conference, 3-13, 8-17

press release, 2-13, 3-12—3-14, 4-2, 8-17

Q

quality assurance (QA), 2-13, 3-8, 4-4, 5-3, 

5-4, 5-15, 5-16, 5-22, 7-3, 8-10, 9-9, 10-8,

15-6, 16-7, 17-7, 17-8, 19-5, 19-11

quality assurance project plan (QAPP), Ch. 5,

2-13, 3-2, 3-8, 6-2, 7-1, 8-4, 8-8, 9-10, 

11-5

quality control (QC), 2-13, 4-4, 4-9—4-11, 

5-4, 5-10—5-12, 5-16, 5-19—5-22, 7-3, 

7-10, 8-4, 8-11, 9-6, 9-7, 10-8, 11-5, 11-7,

13-3, 14-5, 15-6, 15-7, 17-7, 17-8, 17-13,

17-18, 19-11, 19-12, 19-19

external QC, 5-4

internal QC, 5-4

R

rain gauge, 7-14, 10-12

reagent(s), 3-1, 4-4, 4-5, 5-10, 5-11, 5-21, 6-3,

7-5—7-7, 7-9, 9-5—9-7, 9-9—9-11, 9-13,

10-7—10-9, 11-3, 11-4, 11-5, 11-7, 11-8,

15-6, 15-9, 17-12, 17-17

red tide, 10-3, 12-6, 19-9, 19-17

refractivity, 14-3, 14-4

refractometer(s), 14-4—14-6

relative percent difference (RPD), 5-5, 5-6

relative standard deviation (RSD), 5-5, 5-6

replicate, 5-10

representativeness, 5-8, 5-18, 5-19, 5-22

risk management, 3-6

runoff, 2-8, 2-10, 6-5, 7-14, 8-9, 9-2, 10-2,

10-3, 10-6, 10-11, 11-2, 12-2, 12-3, 12-6,

15-2, 15-4, 15-6, 17-1, 17-2, 18-4, 

S

safety, 3-5—3-7, 4-5, 4-6, 5-3, 5-19, 7-1—

7-3, 7-5, 9-7, 10-8, 11-5, 11-7, 13-3, 14-5,

15-7, 16-11, 19-5, 19-11, 19-19 

salinity, Ch. 14, 2-11, 5-12, 5-19, 6-2, 6-3, 

6-5, 9-1, 9-6—9-8, 9-10, 9-12, 17-15, 

18-3—18-5

sample

duplicate, 5-10, 5-12

fixed, 9-6, 9-9, 9-11, 9-13

spiked, 5-11, 5-12

split, 5-11, 5-12, 17-7, 17-18

seagrass, 2-8, 16-4, 18-1, 18-5, 18-6, 18-10,

19-4

Secchi, 3-5, 5-19, 6-6, 8-9, 8-12, 15-4—15-8,

18-11, 18-12, 19-12

sediment, 2-3, 2-7, 2-10, 7-15, 7-16, 9-2, 9-3,

10-2, 10-7, 10-10, 10-12, 11-2, 15—15-5,

15-9, 17-3, 17-5, 17-7—17-9, 17-12, 

18-1—18-4, 18-10—18-12, 19-2—19-4,

19-17 

toxins in, 12-5—12-7

sensitivity, 5-9, 5-18, 11-4

shellfish, 2-7, 7-13, 9-2, 10-3, 12-3, 12-6, 

12-7, 17-1, 17-2, 17-7, 17-11, 17-14, 17-

15, 18-4, 19-3—19-6, 19-9, 19-14, 19-16,

19-17, 19-20

shoal grass, 18-6

shoreline landmark method, 7-11

species, 10-1, 10-5, 12-4

mercury, 12-4

nitrogen and phosphorus, 10-6

spectrophotometer, 10-7, 10-8, 12-7
I-5

Volunteer Estuary Monitoring: A Methods Manual

Index

spikes, 5-22

standard deviation, 5-4, 8-8, 8-9

standard operating procedures (SOPs), 4-5, 

5-2, 5-3, 5-9, 5-13, 5-15, 5-16, 5-19, 5-20

standard(s), 5-9, 5-11, 5-21, 7-7, 8-12, 9-6,

10-7, 11-3—11-5, 11-7—11-9, 14-5, 14-6,

15-7—15-9, 16-11, 17-12, 19-5

STORET, 5-3, 8-4

stormwater runoff, 2-5, 2-6, 9-14, 10-2, 15-2,

17-3

stratification, 2-2, 2-11, 6-5, 7-15, 9-3, 9-4,

13-2, 14-2

submerged aquatic vegetation (SAV), Ch. 18,

2-10, 6-2, 7-13, 8-8, 10-3

SAV index, 18-6, 18-7

T

TBT (tributyltin), 12-6

temperature, Ch. 13, 2-9, 5-12, 5-19, 6-2, 6-3,

6-6, 7-2, 7-5, 7-6, 8-13, 9-3, 9-6—9-8, 9-

12, 9-14, 9-15, 11-4, 11-5, 11-7, 11-8, 

14-2—14-4, 15-2, 15-3, 17-5, 17-10—

17-13, 17-15, 17-18, 18-3, 19-8, 19-9

air, 7-14, 13-2, 13-4

thermometer, 7-8, 7-9, 7-14, 13-1, 13-3, 13-4,

14-6

tide, 2-11, 6-5, 6-6, 7-4, 7-9, 7-15, 13-2, 14-2,

14-3, 18-3, 18-6, 18-8, 18-10

titration, 7-6, 9-5, 9-6, 9-9—9-11, 9-13, 11-7,

11-8, 14-4, 14-5

titrator(s), 11-7, 11-8

total coliforms, 17-1, 17-2, 17-4—17-6, 

17-12—17-14, 17-17

total dissolved solids, 6-3

total solids, Ch. 15, 2-6, 5-12

toxicity

acute, 12-2

chronic, 12-2

toxin, Ch. 12, 2-6, 2-7, 2-10, 19-17

transect, 18-7, 18-8, 19-4

transparency, 6-2, 19-12

transparency tube(s), 15-4, 15-6—15-9

tributary, 2-2, 2-5, 8-14, 13-2, 18-5

turbidity, Ch. 15, 2-6, 2-9, 2-10, 5-12, 6-2, 

7-14, 8-9, 8-12, 14-2, 19-2

meter, 15-6—15-8

turtle grass, 18-5, 18-6

U

U.S. Environmental Protection Agency (EPA),

2-12, 3-3, 3-11, 5-3, 5-13, 5-16—5-18, 

5-20, 8-4, 12-4, 16-5, 17-5, 17-6, 17-10,

17-11, 17-13, 19-3

V

Van Dorn (water sampler), 7-17, 9-4, 9-7, 

10-5, 19-11, 19-15

visual assessment, 7-12, 19-11

voucher collection, 5-7, 5-8, 5-19

W

waste, 7-5, 7-8, 7-9, 9-5, 9-10, 10-10, 17-11

watershed, 2-4, 2-5, 2-8, 3-5, 3-9, 4-6, 6-4, 

7-12, 8-14, 10-4, 10-6, 10-11, 10-12, 15-2,

15-4, 17-2, 17-4, 17-15

survey, 5-14

wet deposition, 10-11, 10-12

wetlands, 2-3, 2-5, 12-4, 19-17, 19-21

Whirl-pak (bag(s)), 7-15—7-17, 10-9, 11-5,

15-8, 15-10, 17-8, 17-9

widgeon grass, 18-5

wild celery, 18-5

Winkler (method) (titration), 5-19, 9-5, 9-6, 

9-8—9-11

wrack, 17-3, 17-5

Z

zooplankton, 6-5, 10-10, 19-7—19-10, 19-12,

19-13, 19-15
I-6

Volunteer Estuary Monitoring: A Methods Manual

Index