EPA/620-R-07/001

February 2007

Condition of Estuaries and Bays of

 Hawaii for 2002:

A Statistical Summary

Office of Research and Development

U.S. Environmental Protection Agency

Washington, DC 20460
ii

List of Authors

Walter G. Nelson1, Richard Brock2, Henry Lee II1, Janet O. Lamberson1, Faith Cole1

Author Affiliations

1

 Western Ecology Division, National Health and Environmental Effects Laboratory,

U.S. Environmental Protection Agency, Newport OR 97365

2

 University of Hawaii at Manoa, Honolulu, Hawaii 96822
iii

Preface

This document is one of a series of statistical summaries for the U.S. Environmental

Protection Agency (EPA), National Coastal Assessment Western regional component 

(NCA-West). The program is the coastal component of the nationwide Environmental

Monitoring and Assessment Program (EMAP). This document is the first statistical

summary for the program for the state of Hawaii estuaries and bays. The NCA in the

western region is a collaborative effort between EPA and the states of Hawaii, Alaska,

California, Oregon and Washington, the territories of Guam and American Samoa, and

the National Oceanic and Atmospheric Administration (NOAA). The program is

administered through the EPA and implemented through partnerships with a

combination of federal and state agencies, universities and the private sector.

The appropriate citation for this report is:

Nelson, Walter G.; Brock, Richard; Lee II, Henry; Lamberson, Janet O.; Cole,

Faith. 2007. Condition of Estuaries and Bays of Hawaii for 2002: A Statistical

Summary. Office of Research and Development, National Health and

Environmental Effects Research Laboratory, EPA/620-R-07/001. 

Disclaimer

The information in this document has been funded wholly or in part by the U.S.

Environmental Protection Agency under a Cooperative Agreement with the University of

Hawaii (CR-832114). It has been subjected to review by the National Health and

Environmental Effects Research Laboratory and approved for publication. Approval

does not signify that the contents reflect the views of the agency, nor does mention of

trade names or commercial products constitute endorsement or recommendation for

use. 
iv

Acknowledgments

The NCA-West involves the cooperation of a significant number of federal, state, and

local agencies. The project has been principally funded by the U.S. Environmental

Protection Agency, Office of Research and Development. Moss Landing Marine

Laboratory provided training for the Hawaii field crews.

Project wide information management support during initial phases of the Hawaii

sampling effort was provided by SCCWRP as part of their cooperative agreement. 

Many individuals within EPA made important contributions to Western Coastal EMAP.

Critical guidance and vision in establishing this program was provided by Kevin

Summers of Gulf Ecology Division. Virginia Engle and Linda Harwell of Gulf Ecology

Division were extremely helpful with issues on data analysis. Tony Olsen of Western

Ecology Division has made numerous comments which have helped to improve the

quality of this document. Terrence Fleming of the Region 9 Office of EPA ably served as

the regional liaison with the state participants. Robert Ozretich of WED performed a

detailed review of the database contents used for this analysis, and we additionally

thank him for his extensive quality assurance review of this document.

We thank Pam Tsai and Terrence Fleming of EPA Region 9, and Terence Teruya of the

Hawaii Department of Health for their reviews of the draft report.
v

The success of the Western Coastal pilot has depended on the contributions and

dedication of many individuals. Special recognition for their efforts is due the following

participants:

University of Hawaii

Julie Bailey Brock

Bill Cooke

Christine Frazier

Alan Kam

Andrea Messer

Brian Paavo

Southern California Water Resources Research Project (SCCWRP)

Larry Cooper

Steve Weisberg

Moss Landing Marine Laboratory

Russell Fairey

Cassandra Roberts

Hawaii Department of Health

Terence Teruya

Denis Lau

U.S. Environmental Protection Agency

Office of Research and Development

Tony Olsen

Steve Hale

John Macauley

Craig McFarlane

Region 9

Terrence Fleming

Janet Hashimoto

Cindy Lin

Indus Corporation

Patrick Clinton

CSC Corporation

Dan Guzman
vi

Table of Contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvi

List of Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xviii

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xx

1.0 Introduction ..................................................... 1

1.1 Program Background ........................................ 1

1.2 The Hawaii Context for a Coastal Condition Assessment ............. 2

1.3 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.0 Methods ........................................................ 5

2.1 Sampling Design and Statistical Analysis Methods .................. 5

2.1.1 Background ......................................... 5

2.1.2 Hawaii Sampling Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.1.3 Field Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.2 Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.3 Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

2.3.1 Water Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2.3.1.1 Hydrographic Profile . . . . . . . . . . . . . . . . . . . . . . . . . . 20
vii

2.3.1.2 Water Quality Indicators . . . . . . . . . . . . . . . . . . . . . . . 20

2.3.2 Sediment Toxicity Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2.3.2.1 Sediment Collection for Toxicity Testing, Chemical 

Analysis and Grain Size . . . . . . . . . . . . . . . . . . . . . . . . 21

2.3.2.2 Amphipod Toxicity Tests . . . . . . . . . . . . . . . . . . . . . . . 21

2.3.3 Biotic Condition Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2.3.3.1 Benthic Community Structure . . . . . . . . . . . . . . . . . . . 22

2.3.3.2 Fish Community Structure . . . . . . . . . . . . . . . . . . . . . . . 24

2.3.3.3 Holothurian Contaminant Sampling and Chemistry Analyses 25

2.3.3.4 Bacterial Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2.3.4 Sediment Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2.4 Quality Assurance/ Quality Control of Chemical Analyses . . . . . . . . . . . 29

2.4.1 Metals in Sediment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

2.4.2 Organics in Sediment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

2.4.3 Chemical Residues in Tissues . . . . . . . . . . . . . . . . . . . . . . . . . . 31

2.5 Data Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

2.6 Unsamplable Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

2.7 Lessons Learned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.0 Indicator Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.1 Habitat Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.1.1 Water Depth at Sample Sites . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.1.2 Salinity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.1.3 Water Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
viii

3.1.4 pH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.1.5 Sediment Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.1.6 Water Quality Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.1.7 Water Column Stratification . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

3.2 Exposure Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

3.2.1 Dissolved Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

3.2.2 Sediment Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3.2.2.1 Sediment Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3.2.2.2 Sediment Organics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.2.3 Sediment Toxicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

3.2.4 Tissue Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

3.2.5 Bacterial Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

3.3 Biotic Condition Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

3.3.1 Infaunal Abundance, Species Richness and Taxonomic

 Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

3.3.2 Hard Bottom Habitat Composition . . . . . . . . . . . . . . . . . . . . . . 118

3.3.2.1 Algal Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

3.3.2.2 Coral Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

3.3.2.3 Macroinvertebrate Composition . . . . . . . . . . . . . . . . . . 122

3.3.3 Fish Species Richness, Abundance and Biomass . . . . . . . . . . 124

4.0 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
ix

List of Figures

Figure 2.1-1. Location of Hawaii EMAP survey sites on the islands of Kauai

 and Niihau . .................................................. 8

Figure 2.1-2. Location of Hawaii EMAP survey sites on the island of Oahu, excluding

the Oahu urbanized estuary study sites. ............................. 9

Figure 2.1-3. Location of Hawaii EMAP survey sites on the islands of Maui

and Molokai . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 2.1-4. Location of Hawaii EMAP survey sites on the island of Hawaii . . . . . 11

Figure 2.1-5. Location of Hawaii EMAP survey sites for the intensification study within

 the urbanized estuaries on the island of Oahu . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 3.1-1. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. bottom

depth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Figure 3.1-2. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. bottom

depth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Figure 3.1-3. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. salinity

of bottom waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Figure 3.1-4. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. salinity

of bottom waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Figure 3.1-5. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. temperature

of bottom waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Figure 3.1-6. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs.

temperature in bottom waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Figure 3.1-7. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. pH in

bottom waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Figure 3.1-8. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. pH in

bottom waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Figure 3.1-9. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. percent

silt-clay of sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Figure 3.1-10. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. percent

silt-clay of sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
x

Figure 3.1-11. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. percent

total organic carbon of sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Figure 3.1-12. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. percent

total organic carbon of sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Figure 3.1-13. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean concentration of chlorophyll a. . . . . . . . . . . . . . . . . . . . . . . . . 52

Figure 3.1-14. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column concentration of chlorophyll a. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Figure 3.1-15. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean nitrate concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Figure 3.1-16. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean nitrate concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Figure 3.1-17. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean nitrite concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Figure 3.1-18. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean nitrite concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Figure 3.1-19. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column ammonium concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Figure 3.1-20. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column ammonium concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Figure 3.1-21. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean total nitrogen (nitrate + nitrite + ammonium) concentration. . . 56

Figure 3.1-22. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean total nitrogen (nitrate + nitrite + ammonium) concentration. . . 56

Figure 3.1-23. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean orthophosphate concentration. . . . . . . . . . . . . . . . . . . . . . . . . 57

Figure 3.1-24. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean orthophosphate concentration. . . . . . . . . . . . . . . . . . . . . . . . . 57

Figure 3.1-25. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean ratio of total nitrogen (nitrate + nitrite + ammonium) concentration

to total orthophosphate concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
xi

Figure 3.1-26. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean ratio of total nitrogen (nitrate + nitrite + ammonium) concentration

to total orthophosphate concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Figure 3.1-27. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean silicate concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Figure 3.1-28. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean silicate concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Figure 3.1-29. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. bottom

water turbidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Figure 3.1-30. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. bottom

water turbidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Figure 3.1-31. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. surface

water turbidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Figure 3.1-32. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. surface

water turbidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Figure 3.1-33. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column Secchi depth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Figure 3.1-34. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column Secchi depth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Figure 3.1-35. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. )Ft

stratification index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Figure 3.1-36. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. )Ft

stratification index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Figure 3.2-1. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. dissolved

oxygen of bottom waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Figure 3.2-2. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. dissolved

oxygen of bottom waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Figure 3.2-3. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. dissolved

oxygen of surface waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Figure 3.2-4. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. dissolved

oxygen of surface waters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
xii

Figure 3.2-5. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of arsenic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Figure 3.2-6. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of arsenic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Figure 3.2-7. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of cadmium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Figure 3.2-8. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of cadmium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Figure 3.2-9. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of chromium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Figure 3.2-10. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of chromium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Figure 3.2-11. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of copper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Figure 3.2-12. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of copper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Figure 3.2-13. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of lead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Figure 3.2-14. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of lead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Figure 3.2-15. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of mercury. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Figure 3.2-16. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of mercury. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Figure 3.2-17. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of nickel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Figure 3.2-18. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of nickel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Figure 3.2-19. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of selenium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
xiii

Figure 3.2-20. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of selenium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Figure 3.2-21. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of silver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Figure 3.2-22. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of silver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Figure 3.2-23. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of tin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Figure 3.2-24. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of tin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Figure 3.2-25. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of zinc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Figure 3.2-26. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of zinc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Figure 3.2-27. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of total PAHs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

Figure 3.2-28. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of total PAHs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

Figure 3.2-29. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of total PCBs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Figure 3.2-30. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of total PCBs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Figure 3.2-31. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of total DDT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Figure 3.2-32. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of total DDT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Figure 3.2-33. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of alpha-chlordane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Figure 3.2-34. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. vs.

sediment concentration of alpha-chlordane. . . . . . . . . . . . . . . . . . . . . . . . . . 92
xiv

Figure 3.2-35. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. percent

control corrected survivorship of Ampelisca abdita. . . . . . . . . . . . . . . . . . . . . 94

Figure 3.2-36. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. percent

control corrected survivorship of Ampelisca abdita. . . . . . . . . . . . . . . . . . . . . 94

Figure 3.2-37. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. surface

water sample enterococci colony counts. . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Figure 3.2-38. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. surface

water sample enterococci colony counts. . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Figure 3.2-39. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. surface

water sample Clostridium colony counts. . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Figure 3.2-40. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. surface

water sample Clostridium colony counts. . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Figure 3.2-41. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. surface

water sample fecal coliform counts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Figure 3.2-42. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. surface

water sample fecal coliform counts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Figure 3.3-1. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. total

number of species of benthic infauna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Figure 3.3-2. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. total number

of species of benthic infauna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Figure 3.3-3. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. H’ 

diversity of the benthic infaunal community. . . . . . . . . . . . . . . . . . . . . . . . . 116

Figure 3.3-4. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. H’ 

diversity of the benthic infaunal community. . . . . . . . . . . . . . . . . . . . . . . . . 116

Figure 3.3-5. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. total

abundance of benthic infauna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Figure 3.3-6. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. total

abundance of benthic infauna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Figure 3.3-7. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. total

number of fish species observed on visual transects. . . . . . . . . . . . . . . . . . 126

Figure 3.3-8. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. the H’
xv

diversity index for fishes observed on visual transects. . . . . . . . . . . . . . . . 126

Figure 3.3-9. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. 

abundance of fishes observed on visual transects. . . . . . . . . . . . . . . . . . . . 127

Figure 3.3-10. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. the

estimated biomass of fishes observed on visual transects. . . . . . . . . . . . . 127
xvi

List of Tables

Table 2.1-1. Hawaii sampling sites with station coordinates of locations sampled. 13

Table 2.3-1. Core environmental indicators for the National Coastal Assessment

survey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Table 2.3-2. List of stations with collection of holothurians for tissue analysis. . . . . 25

Table 2.3-3. Compounds analyzed in sediments and holothurian tissues. . . . . . . 27

Table 2.3-4. Summary of NCA chemistry sample collection, preservation, and holding

time requirements for sediment and tissue samples. . . . . . . . . . . . . . . . . . . 28

Table 2.4-1. Units, method detection limits (MDL), reporting limits (RL), analytical

method, and responsible laboratory for sediment chemistry. . . . . . . . . . . . . 33

Table 2.4-2. Units, method detection limits (MDL), reporting limits (RL), analytical

method, and responsible laboratory for tissue chemistry. . . . . . . . . . . . . . . . 35

Table 2.4-3. Summary of performance of Hawaii analytical laboratories with regard to

QA/QC criteria for analysis of reference materials, matrix spike recoveries, and

relative percent differences (RPD) of duplicates. . . . . . . . . . . . . . . . . . . . . . 37

Table 3.2-1. Summary statistics for sediment metal concentrations (:g/g, dry weight)

for the Hawaii estuaries and bays stations (N=45). . . . . . . . . . . . . . . . . . . . 72

Table 3.2-2. Summary statistics for sediment metal concentrations (:g/g, dry weight)

for the Oahu urbanized estuaries stations (N=26). . . . . . . . . . . . . . . . . . . . 73

Table 3.2-3. Summary statistics for sediment organic pollutants (ng/g, dry weight)

for the Hawaii estuary and bay stations (N=42). . . . . . . . . . . . . . . . . . . . . . . 87

Table 3.2-4. Summary statistics for sediment organic pollutants (ng/g, dry weight)

for the Oahu urbanized estuary stations (N=28). . . . . . . . . . . . . . . . . . . . . . 88

Table 3.2-5. Holothurian tissue residues of metals (μg/g wet weight) from 11 Hawaii

estuaries and bays sites and 2 Oahu urbanized estuaries sites. . . . . . . . . . 96

Table 3.2-6. Holothurian tissue residues of total PCBs, PAHs, total DDT, and

additional pesticides (ng/g wet weight) in samples from 11 Hawaii estuaries

and bay sites and 2 Oahu urbanized estuaries sites. . . . . . . . . . . . . . . . . . . 97

Table 3.2-7. Summary of bacteria sampling results, with data presented both for all

samples collected and for samples that met the 6-hour holding time criteria. . 99
xvii

Table 3.3-1. Summary of the soft bottom taxa identified from 74 Hawaii EMAP

stations where sediment was sampled. . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Table 3.3-2. Summary of biological parameters at all stations where underwater

transect measurements were carried out. . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Table 3.3-3. The ten most abundant algal taxa observed on the underwater 

transects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Table 3.3-4. The ten most abundant coral taxa observed on the underwater

transects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Table 3.3-5. The ten most abundant macroinvertebrate taxa observed on the

underwater transects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Table 3.3-6. The ten most abundant fish taxa observed on the underwater

transects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
xviii

 List of Acronyms

BEST Biomonitoring of Environmental Status and Trends Program

CDF Cumulative distribution function

CEB Coastal Ecology Branch, Western Ecology Division (EPA)

CFU Colony Forming Units

CRM Certified Reference Material

CVAA Cold Vapor Atomic Adsorption

CWA Clean Water Act 

DO Dissolved Oxygen Concentration

DQO Data Quality Objectives

EMAP Environmental Monitoring and Assessment Program

EPA U.S. Environmental Protection Agency

ERI Environmental Research Institute, Univ. of Conn

ERM Effects Range Median

GAO U. S. General Accounting Office

GCECD Gas Chromatography and Electron Capture Detection

GCMS Gas Chromatography/Mass Spectroscopy

GFAAS Graphite Furnace Atomic Absorption Spectrometry

GIS Geographic Information System

GPL GPL Laboratories

HDOH Hawaii Department of Health

ICPAES Inductively-Coupled Plasma Atomic Emission Spectrometer

ICPMS Inductively Coupled Plasma-Mass Spectrometry

ICPOES Inductively Coupled Plasma Optical Emission Spectroscopy

IM Information Manager

LCM Laboratory Control Material

LCS Laboratory Control Standard

MDL Method Detection Limit

MQO Methods Quality Objectives 

MS Matrix Spike

NCA National Coastal Assessment

NCA-West National Coastal Assessment - Western regional component

NCL EPA’s National Contract Laboratory

NOAA National Oceanic and Atmospheric Administration

N/P Nitrogen to Phosphorus

NTU Turbidity

ORD EPA Office of Research and Development

PAH Polyaromatic Hydrocarbons

PCB Polychlorinated Biphenyls

QA/QC Quality Assurance/Quality Control

QAC Quality Assurance Coordinator

RL Reporting Limit
xix

RPD Relative Percent Difference

RSG Random Sampling Generator

RTS Random Tessellation Stratified

SCCWRP Southern California Water Resources Research Project

SDTP Standardized Data Transfer Protocols

SRM Standard Reference Material

TOC Total Organic Carbon

TSS Total Suspended Solids

WED Western Ecology Division
xx

Executive Summary

As a part of the National Coastal Assessment (NCA), the Environmental Monitoring

and Assessment Program (EMAP) of US EPA initiated a pilot study of the estuarine

resources of the main islands of Hawaii in 2002. This study provides the first

probabilistic assessment of the condition of the estuaries and bays of Hawaii. The

objectives of the program were: to assess the condition of estuarine resources of

Hawaii based on a range of indicators of environmental quality using an integrated

survey design; to establish a baseline for evaluating how the condition of the estuarine

resources of Hawaii changes with time; to develop and validate improved methods for

use in future coastal monitoring and assessment efforts in Hawaii; and to transfer the

technical approaches and methods for designing, conducting and analyzing data from

probability based environmental assessments to the state of Hawaii.

For Hawaii, the focus of the study during 2002 was all estuaries and the semienclosed

coastal embayments of the state. The study utilized a stratified, random sampling

design, with the base study consisting of 50 sites probabilistically assigned across the

estuaries and bays of Hawaii. Additionally, an intensification study was conducted

that consisted of 30 sites distributed among the urbanized estuaries located within the

city of Honolulu on the south shore of the island of Oahu. The two data sets were

analyzed separately. Cumulative distribution functions (CDFs) were produced using

appropriate sampling area weightings to represent the areal extent associated with

given values of an indicator variable for both the Hawaii estuaries and bays study and

the Oahu urbanized estuary study. 

The environmental condition indicators used in this study included measures of: 1)

general habitat condition (depth, salinity, temperature, pH, sediment characteristics),

2) water quality indicators (chlorophyll a, nutrients, turbidity), 3) pollutant exposure

indicators (dissolved oxygen concentration, sediment contaminants, invertebrate

tissue contaminants, sediment toxicity), and 4) benthic condition indicators (diversity

and abundance of benthic infauna and fishes).

In contrast to the mainland west coast, the indicators of general habitat condition

(temperature, salinity, pH) showed relatively narrow ranges of values, e.g. water

temperatures ranged only from 24 to 28 °C, with a maximum surface to bottom

difference of 2.5 °C. About 73% of the area of the Hawaii estuaries and bays had

sediments composed of sands, about 21% was composed of intermediate muddy

sands, and about 6% was composed of muds. The Oahu urbanized estuaries (29

stations) had a greater proportion of area characterized by muds (62%), and less area

characterized by sands (15%) or intermediate muddy sands (23%). The 90th percentile

of area of the Hawaii estuaries and bays had a sediment TOC level of <1 %. The 90th

percentile of area of the Oahu urbanized estuaries had a sediment TOC level of 2.1

%, which is expected given the more depositional character of these harbors. 
xxi

The ranges of values of chlorophyll a were very similar between the Hawaii estuaries

and bays and the Oahu urbanized estuaries. Maximum values were several orders of

magnitude lower that those typical of coastal sites on the mainland west coast. Total

nitrogen and phosphorus indicators generally showed similar patterns in their CDFs,

with high values being observed in a very small percentage of area, thus generating

extensive right hand tails to CDF distributions. For example, the average water column

concentration of total nitrogen of Hawaii estuaries and bays ranged from 2.5 to 284 :g

L-1, but only 10% of estuarine area had nitrate values that exceeded concentrations of

67 :g L-1. Approximately 40% of area of Hawaii estuaries and bays, and 74% of area

in Oahu urbanized estuaries, had molar ratios of average water column total nitrogen

to total phosphorus (N/P) values # 16, suggesting nitrogen limitation. 

Turbidity at the surface was below 3.4 ntu, representing 90% of area of both the

Hawaii estuaries and bays and the Oahu urbanized estuaries. Valid Secchi depth

readings were obtained at too few stations to provide a useful indicator of water clarity. 

In most cases this was due to the high degree of water clarity, such that the Secchi

disk was still visible at the bottom. There was little indication of water column

stratification within either the Hawaii estuaries and bays or the Oahu urbanized

estuaries sampled, suggesting well mixed water columns are typical during the

sampling period.

Among pollutant exposure indicators, approximately 7% of estuarine area for the 

Hawaii estuaries and bays and 8% in the Oahu urbanized estuaries had bottom water

dissolved oxygen concentrations slightly # 5 mg/L. 

High values of potentially toxic metals generally occurred in a very small percentage of

the area of Hawaii estuaries and bays sampled. With the exception of nickel for which

the Effects Range Median concentration (ERM) is unreliable, chromium and mercury

exceeded the ERM in # 1% of the area. While concentrations of metals were

generally higher in the Oahu urbanized estuaries, only copper and mercury exceeded

the ERM values, and only in 4% and 5% of area, respectively. Eighty-seven percent

of area of Hawaii estuaries and bays had undetectable concentrations of PAHs, as

compared to only 8% of the area of the Oahu urbanized estuaries. Thirty-nine percent

of the area of the Hawaii estuaries and bays had undetectable concentrations of

PCBs, as compared to only 12% of the area of the Oahu urbanized estuaries. Thirtyfour percent of the area of the Hawaii estuaries and bays had undetectable levels of

DDT, as compared to 36% of the area of the Oahu urbanized estuaries. There were

no exceedances of the ERM for any organic compound analyzed at any station.

Sediment toxicity tests with the amphipod Ampelisca abdita found no instances of

elevated sediment toxicity (control corrected survivorship # 80 %) in Oahu urbanized

estuaries, but in approximately 10% of the area of Hawaii estuaries and bays

amphipod survivorship was less than 80%.
xxii

Samples of two species of holothurians (sea cucumbers) were analyzed for tissue

contaminants in pilot method development effort. Mercury, cadmium, and silver were

undetected in holothurian tissue samples. PCBs and DDT were detected in some

tissue samples at low levels, while PAHs and other pesticides were not detected. Total

sample size was small and analytical issues were present with the tissue matrix, so

that these results have high uncertainty.

Sampling for three bacterial indicators (enterococci, Clostridium perfringens, fecal

coliforms) showed that in most cases the density of colony forming units was low in

the waters of Hawaii. Approximately 4% of the area of Hawaii estuaries and bays and

13% of Oahu urbanized areas exceeded the Hawaii criterion for enterococci. The state

enterococci criterion requires multiple samples, and the EMAP samples are single

events, so results should not be interpreted to mean that locations with values above

the criterion would technically violate water quality standards for bacteria.

Sediments were encountered at all but five stations in the 79 sites sampled. A total of

214 soft sediment benthic taxa were recorded. Benthic species richness on a per

sample basis ranged from 4 to 52 species per sample in the samples from Hawaii

estuaries and bays, and from 3 to 43 species per sample from the Oahu urbanized

estuaries. On an areal basis, 50% of the area of the Hawaii estuaries and bays had a

species richness less than 22 species per sample, and 90% had a richness less than

38.5 species per sample. The Oahu urbanized estuaries had a lower richness, with

50% of the area of these estuaries having fewer than 8 species per sample and 90%

of the area having less than 21 species per sample.

Benthic infaunal density in samples from Hawaii estuaries and bays ranged from 5 to

1927 individuals per sample, and had a similar range of 8 to 1872 individuals per

sample in samples from Oahu urbanized estuaries. On an areal basis, 50% of the

area of the Hawaii estuaries and bays had a benthic density less than 270 individuals

per sample, while in the Oahu urbanized estuaries, 50% of the area had benthic

densities less than 76 individuals. Abundance was dominated by nematodes,

oligochaetes, and polychaetes. Fully 57 % of the polychaete taxa are classified as

nonindigenous in origin.

Underwater biological surveys to assess condition of hard substrata were carried out

by SCUBA divers at 38 of the 79 (48%) completed survey sites, only three of which

were located in the Oahu urbanized estuaries. Mean algal percent cover ranged

between 0 and 70%, with 90% of the area of Hawaii estuaries and bays having an

algal percent coverage less than approximately 14%. Corals were found at 26 of 38

(68%) stations surveyed. At sites with corals present, the number of coral species

ranged from 1 to 9 per transect, with a mean of 4 species per transect. Coral

coverage at the 26 sites with corals present ranged from 0.2% to 99.7% with a mean

of 16.4%. 
xxiii

Visual censuses of fishes were carried out at 38 of the 79 Hawaiian stations and

fishes were encountered at 34 of the 38 sites. In total, 110 species/taxa were

encountered. The mean number of fish taxa per transect was 9, mean number of

fishes/transect was 56 and mean estimated biomass was 19 g/m2

 per transect. Fish

species richness on a per sample basis ranged from 0 to 31 species per transect in

the samples from Hawaii estuaries and bays, and on an areal basis, approximately

50% of the area had less than 8 species per transect. Fish abundance per transect

ranged from 0 to 278 individuals, and on an areal basis, 50% of the area had less than

48 individuals per transect. Estimated fish biomass per transect in samples from

Hawaii estuaries and bays ranged from 0 to 18.6 kg per transect, and on an areal

basis, 50% of the area had less than 0.6 kg per transect.

The NCA assessment of condition of Hawaiian waters represents the first quantitative

estimates of condition across the Hawaiian Islands for many parameters. The project

also successfully demonstrated the application of techniques, such as underwater

visual surveys of hard substrates, which are new to the NCA program. 
1

1.0 Introduction

1.1 Program background

Safeguarding the natural environment is fundamental to the mission of the US

Environmental Protection Agency (EPA). The legislative mandate to undertake this

part of the Agency’s mission is embodied, in part, in the Clean Water Act (CWA).

Sections of this Act require the states to report the condition of their aquatic resources

and list those not meeting their designated use (Section 305b and 303d respectively).

Calls for improvements in environmental monitoring date back to the late 1970’s, and

have been recently reiterated by the U. S. General Accounting Office (U.S. GAO,

2000). The GAO report shows that problems with monitoring of aquatic resources

continue to limit states’ abilities to carry out several key management and regulatory

activities on water quality. At the national level, there is a clear need for coordinated

monitoring of the nation’s ecological resources. As a response to these needs at state

and national levels, the EPA Office of Research and Development (ORD) has

undertaken research to support the Agency’s Regional Offices and the states in their

efforts to meet the CWA reporting requirements. The Environmental Monitoring and

Assessment Program (EMAP) is one of the key components of that research and

EMAP-West is the newest regional research effort in EMAP. From 1999 through 2005,

EMAP-West has worked to develop and demonstrate the tools needed to measure

ecological condition of the aquatic resources in the 14 western states in EPA’s

Regions 8, 9, and 10. 

The Coastal Component of EMAP-West began as a partnership with the states of

California, Oregon and Washington, the National Oceanic and Atmospheric

Administration, and the Biomonitoring of Environmental Status and Trends Program

(BEST) of the U.S. Geological Survey to measure the condition of the estuaries of

these three states. Sampling began during the summer of 1999 and the initial phase of

estuarine sampling was completed in 2000. Data from this program is the basis for

individual reports of condition for each state, as well as to providing data to the

National Coastal Assessment.

The US EPA’s National Coastal Assessment (NCA) is a five-year effort led by EPA’s

Office of Research and Development to evaluate the assessment methods it has

developed to advance the science of ecosystem condition monitoring. This program

has surveyed the condition of the Nation’s coastal resources (estuaries and offshore

waters) by creating an integrated, comprehensive coastal monitoring program among

the coastal states to assess coastal ecological condition. The NCA is accomplished

through strategic partnerships with all 24 U.S. coastal states. Using a compatible,

probabilistic design and a common set of survey indicators, each state conducts the

survey and assesses the condition of their coastal resources independently. Because

of the compatible design, these estimates can be aggregated to assess conditions at

the EPA Regional, biogeographical, and national levels.
2

This report provides a statistical summary of the data from 2002 for the estuarine

systems of the state of Hawaii. A second assessment of condition of coastal

resources of the Hawaiian Islands is planned for the summer of 2006.

1.2 The Hawaii Context for a Coastal Condition Assessment

The Hawaiian Islands are the most isolated archipelago in the world. This isolation

has resulted in Hawaii’s flora and fauna having the highest percentage of endemic

species of anywhere in the world. This singular distinction has a downside: over the

last 200 years with development and westernization, Hawaii has suffered the greatest

number of known extinctions for any fauna and flora. There are many reasons for this

great loss of native species; habitat destruction, pollution, human over use and the

introduction of alien species have all played key roles.

The population of Hawaii has fluctuated through time. Following contact with the

West, disease took its toll on the native population such that by the 1870's there were

less than 60,000 individuals. In 1900 the population had grown to 154,000 people

primarily through the importation of labor for agriculture. Today, Hawaii’s population

exceeds 1.2 million people and more than 90% live in urban centers. Because of the

relatively small land area of the islands, development, population and economic

growth have all exacerbated the impacts to native ecosystems. Human population

growth in Hawaii is a principal driver for many ecological stressors such as habitat

loss, pollution, and nutrient enhancement which alter coastal ecosystems and affect

the sustainability of coastal ecological resources. Increased globalization of the

economy is a major driver influencing the introduction of exotic species into port and

harbors.

Estuaries represent less than 1% of the coastal ocean area around the Hawaiian

Islands and these are best developed on the older islands (Kauai and Oahu). Most of

these estuaries are small occupying less than a square kilometer. Pearl Harbor which

is the largest remaining Hawaiian estuary has a water surface area of approximately

58 km2

 and is the country’s largest naval port. However, historically, estuarine waters

were once more important. In the Moiliili-Waikiki-Kewalo districts of Honolulu on

Oahu, approximately 48% of the land area was formerly occupied by

wetland/estuarine habitat in 1887. Today these aquatic features are absent and

remaining estuarine waters are all channelized conduits that rapidly transport storm

water runoff directly to the sea. Sedimentation problems associated with land use

changes may be especially acute in coastal areas of Hawaii because of the

combination of steep coastal watersheds, high seasonal rainfall, and agricultural and

other land development. 

Estuaries serve as important nursery habitat for a number of commercial and

recreational Hawaiian fishery resources. These aquatic features also serve as natural

biofilters sequestering sediment and pollutants adsorbed to particulate materials thus

lessening the impact of storm water runoff to adjacent coral reefs. The development
3

of the hinterland surrounding most of Hawaii’s largest estuaries with concurrent

pollution and alien species introductions has resulted in tremendous changes to the

abundance and species composition of important estuarine species. Causal

mechanisms responsible for these changes have not been quantitatively defined and

the rate of these changes has not been measured. 

Within estuaries and coastal embayments, benthic environments are areas where

many types of impacts from the stressors described above will tend to accumulate. 

Deposition of toxic materials, accumulation of sediment organics, and oxygen

deficiency of bottom waters typically have a greater impact on benthic organisms than

on planktonic and nektonic organisms because of their more sedentary nature. Longterm studies of the macrobenthos (Reish, 1986, Holland and Shaughnessey, 1986)

demonstrate that macrobenthos is a sensitive indicator of pollutant effects. Benthic

assemblages are also closely linked to both lower and higher trophic levels, as well as

to processes influencing water and sediment quality, and therefore appear to integrate

responses of the entire estuarine system (Leppakoski, 1979; Holland and

Shaughnessey, 1986).

Quantitative baseline information and establishment of long-term comprehensive

monitoring programs are needed as a first step for any rational program of pollution

abatement and habitat restoration. Not only should the impacted areas be studied but

parallel studies must be undertaken in remaining high quality habitats to ascertain if

mitigation programs are being successful. 

The principal population and commercial center for Hawaii is on the south shore of

Oahu, in an area encompassing Pearl Harbor, the Port of Honolulu, and several other

estuaries or embayments that are highly altered and surrounded by a high density

urban setting. The rest of the Hawaiian Islands has a much lower population density.

While it may be presumed that the magnitude of anthropogenic impacts will be highest

in the urbanized estuaries of Oahu, this hypothesis has not yet been tested. 

Therefore, in addition to the assessment of condition for the Hawaiian Islands as a

whole, an intensified level of sampling was conducted within the Oahu urbanized

estuaries. 

1.3 Objectives

The EMAP sampling program conducted in Hawaii in 2002 was a pilot program to

determine the feasibility of conducting condition assessments of coastal resources

throughout the island group and had the following objectives:

1. To assess the condition of estuarine and coastal embayment resources of Hawaii

based on a range of indicators of environmental quality using an integrated survey

design;
4

2. To establish a baseline for evaluating how the conditions of the estuarine resources

of Hawaii may change with time;

3. To develop and validate improved methods for use in future coastal monitoring and

assessment efforts in Hawaii and U.S. Pacific Island territories;

4. To transfer the technical approaches and methods for designing, conducting and

analyzing data from probability based environmental assessments to the state of

Hawaii.
5

2.0 Methods

2.1 Sampling Design and Statistical Analysis Methods

2.1.1 Background

The EMAP approach to evaluating the condition of ecological resources is described

in reports such as Diaz-Ramos et al. (1996), Stevens (1997), Stevens and Olsen

(1999) and is also presented in summaries provided on the internet at the URL:

http://www.epa.gov/nheerl/arm/index.htm

A brief summary from these documents follows. 

Given the fact that it is generally impossible to completely census an extensive

resource, such as the set of all estuaries and bays in Hawaii, a more practical

approach to evaluating resource condition is to sample selected portions of the

resource using probability based sampling. Studies based on random samples of the

resource rather than on a complete census are termed sample surveys. Sample

surveys offer the advantages of being affordable, and of allowing extrapolations to be

made of the overall condition of the resource based on the random samples collected. 

Survey methodologies are widely used in national programs such as forest

inventories, agricultural statistics surveys, national resource inventory, consumer price

index, labor surveys, and such activities as voter opinion surveys.

A survey design provides the approach to selecting samples in such a way that they

provide valid estimates for the entire resource of interest. Designing and executing a

sample survey involves five steps: (1) creating a list of all units of the target population

from which to select the sample, (2) selecting a random sample of units from this list,

(3) collecting data from the selected units, (4) summarizing the data with statistical

analysis procedures appropriate for the survey design, and (5) communicating the

results. The list or map that identifies every unit within the population of interest is

termed the sampling frame. 

The sampling frame for the EMAP Western Coastal Program was developed from

USGS 1:100,000 scale digital line graphs and stored as a GIS data layer in ARC/INFO

program. A series of programs and scrips (Bourgeois et al., 1998) was written to

create a random sampling generator (RSG) that runs in ArcView. Site selection

consisted of using the RSG to first overlay a user-defined sampling grid of hexagons

over the spatial resource which consisted of all estuaries of Hawaii. The area of the

hexagons was controlled by adjusting the distance to hexagon centers, and by

defining how many sample stations were to be generated for each sampling region.

After the sampling grid was overlaid on the estuarine resource, the program randomly

selected hexagons and randomly located a sampling point within the hexagon. Only

one sampling site was selected from any hexagon selected. The program determined
6

whether or not a sampling point fell in water or on land, and sites that fell on land were

not included. The RSG is run iteratively until a hexagon size is determined which

generates the desired number of sampling sites within the resource (Bourgeois et al.,

1998).

Hexagon size may be different for classes of estuarine systems of different areal

extent. The final data analysis which provides the estimates of resource condition

(see Section 2.2) then weights the samples based on the area of the estuarine class. 

Stevens (1997) terms this a random tessellation stratified (RTS) survey design applied

to each estuarine resource class. Because of the area weights, estimates provided in

this report of the percentage of estuarine area associated with given values of the

indicators are not the same as simple proportions based on the number of stations in

a condition category. 

2.1.2 2002 Hawaii Sampling Design

The assessment of the condition of Hawaiian estuaries and coastal embayments

included two design elements. The base study was an assessment of these water

bodies for the main Hawaiian Island chain. An intensification study was also

conducted to assess the condition of the urbanized ports and harbors of the south

shore of the Island of Oahu adjacent to Mamala Bay. The complete Hawaii

assessment combines data from all stations in both design elements for analysis,

using the inclusion probabilities, defined as the total estuarine area in km2

 within a

given design stratum

(= estuarine size class), to weight the representation of samples in the combined

analysis. 

The Hawaii sampling frame was constructed as a GIS coverage that included the total

area of the polygons representing the estuaries and coastal bays in the state. 

Available GIS coverages were not perfect representations of the estuarine resource,

and so the coverages were defined to ensure that they included the resource, but may

have possibly included some nearby land or inland water. The inland boundary of the

sampling frame was defined as the head of salt water influence, while the seaward

boundary was defined by the confluence with the ocean. Sample locations could fall

within any water depth contained within the estuarine resource which was bounded by

the shoreline. Emergent salt marsh areas, if present, were not included in the

sampling frame. For coastal bays, the offshore boundary was constrained to a depth

of 60 ft in order to be conservative in terms of safety for the SCUBA divers used to

obtain bottom samples. There was also considerable uncertainty associated with the

bathymetry used to define this offshore boundary. 

The sampling design for the 2002 Hawaii base study included all estuaries and coastal

bays of the main Hawaiian Island chain, and consisted of a total of 50 sites (Sites 1-

50, Table 2.1-1, Figures 2.1-1, 2.1-2, 2.1-3, 2.1-4). Sample site selection utilized four

hexagonal grid sizes reflecting these four estuary size classes: 0.55, 2.5, 4.98 and
7

6.78 km2 (see Table 2.1-1 for association of grid size with estuary stratum). 

Approximately equal sampling effort was placed in each of four design strata to ensure

that there was at least some level of sampling across the entire range of sizes of

estuaries and bays. No alternate or oversample sites were selected during the

design, and thus any sites which could not be sampled were not replaced. 

Improvements to subsequent versions of the RSG produced after this study allow

incorporation of alternate sample sites if future assessment studies for Hawaii.

The sampling design for the 2002 Hawaii intensification study included Pearl Harbor,

Honolulu Harbor, and the other ports, harbors, marinas and canals located along the

waterfront of the city of Honolulu, with Mamala Bay, and consisted of a total of 30 sites

(Sites 51-80, Table 2.1-1, Figure 2.1-5). The design for this intensification study

incorporated 2 hexagonal grid sizes: 0.86 and 1.24 km2

. The hexagonal grid sizes

were used to locate random sample sites within a total of two strata representing

differing total areas of the estuarine resource in the Oahu urbanized estuaries (see

Table 2.1-1 for association of grid size with estuary stratum). No alternate or

oversample sites were selected during the design, and thus any sites which could not

be sampled were not replaced.

2.1.3 Field Sampling

Field sampling began on April 1, 2002 and concluded on October 30, 2002. Samples

from the Hawaii base study were completed by September 30, 2002. Sampling for the

urbanized estuaries of Oahu began in April, but did not conclude until the end of

October. Pearl Harbor was sampled between Oct. 7-11, 2002. The extended period

required for field work resulted from the logistical issues associated with sampling the

multiple islands of the Hawaiian Island chain, and from delays in receiving permission

to sample within military areas on Oahu. 

Sampling methods are described in detail in the following sections. Water column

measurements and samples were obtained from small boats using standard NCA

methods following guidance provided in the NCA Quality Assurance Project Plan

document (US EPA, 2001). One exception to the use of small boats was a “walk-in”

station located in Halekou Pond on Oahu. Bottom samples and other biotic

measurements were obtained by divers using either snorkel or SCUBA gear. Boats

used in sampling included a kayak to reach a shallow site in Pearl Harbor, a 22 ft. boat

with outboard motor used for much of the sampling on the island of Oahu, and a 43 ft.

chartered vessel used for sampling stations located on the other islands. Because of

the predominant use of small boats, weather conditions were generally moderate, with

maximum wind speeds estimated at 10 mph. Drizzle was encountered only in

sampling station HI02-006 at Wahiawa Bay, Kauai. 
8

Figure 2.1-1. Location of Hawaii EMAP survey sites on the islands of Kauai and Niihau. 
9

Figure 2.1- 2. Location of Hawaii EMAP survey sites on the island of Oahu, excluding the Oahu urbani

sites.
10

Figure 2.1-3. Location of Hawaii EMAP survey sites on the islands of Maui and Molokai.
11

Figure 2.1-4. Location of Hawaii EMAP survey sites on the island of Hawaii.
12

Figure 2.1-5. Location of Hawaii EMAP survey sites for the intensification study within the urbanized e

island of Oahu.
13

Table 2.1-1. Hawaii sampling sites with station coordinates of locations sampled.

Station numbers 51-80 constitute the Oahu urban estuaries intensive study. The Frame

Area represents the total estuarine area within a stratum.

EMAP Sta.

No.

Latitude Longitude Estuary or 

 Coastal Bay

Hex

Size

Frame

Area km2

Stratum

 HI02-0001 21.965 -160.124 Keawanui Bay (Niihau) 4.98 72.873 HI00-003

 HI02-0002 21.941 -160.144 Keawanui Bay (Niihau) 4.98 72.873 HI00-003

 HI02-0003 22.217 -159.534 Wainiha Bay 2.5 26.160 HI00-002

 HI02-0004 21.951 -159.673 Waimea Bay 4.98 72.873 HI00-003

 HI02-0005 21.903 -159.593 Hanapepe Bay 2.5 26.160 HI00-002

 HI02-0006 21.897 -159.575 Wahiawa Bay 0.55 5.168 HI00-001

 HI02-0007 21.991 -159.349 Hanamaulu Stream 2.5 26.160 HI00-002

 HI02-0008 21.575 -158.096 Paukauila Stream 0.55 5.168 HI00-001

 HI02-0009 21.498 -157.839 Kaneohe Bay 6.78 120.848 HI00-004

 HI02-0010 21.494 -157.837 Kaneohe Bay 6.78 120.848 HI00-004

 HI02-0011 21.372 -157.986 Pearl Harbor 6.78 120.848 HI00-004

 HI02-0012 21.476 -157.808 Kaneohe Bay 6.78 120.848 HI00-004

 HI02-0013 21.472 -157.803 Kaneohe Bay 6.78 120.848 HI00-004

 HI02-0014 21.470 -157.783 Kaneohe Bay 6.78 120.848 HI00-004

 HI02-0015 21.451 -157.800 Kaneohe Bay 6.78 120.848 HI00-004

 HI02-0016 21.352 -157.896 Moanalua Stream 0.55 5.168 HI00-001

 HI02-0017 21.432 -157.788 Kaneohe Bay 6.78 120.848 HI00-004

 HI02-0018 21.435 -157.778 Kaneohe Bay 6.78 120.848 HI00-004

 HI02-0019 21.436 -157.752 Halekou Pond 0.55 5.168 HI00-001

 HI02-0020 21.433 -157.748 Nuupia Pond 2.5 26.160 HI00-002

 HI02-0021 21.311 -157.891 Keehi Lagoon 4.98 72.873 HI00-003

 HI02-0022 21.339 -157.684 Waimanalo Bay 4.98 72.873 HI00-003

 HI02-0023 21.320 -157.669 Waimanalo Bay 4.98 72.873 HI00-003

 HI02-0024 21.278 -157.720 Maunalua Bay 4.98 72.873 HI00-003

 HI02-0025 21.271 -157.728 Maunalua Bay 4.98 72.873 HI00-003

 HI02-0026 21.085 -157.026 Kaunakakai Harbor 2.5 26.160 HI00-002

 HI02-0027 20.919 -156.480 Kahului Bay 4.98 72.873 HI00-003

 HI02-0028 20.907 -156.459 Kahului Bay 4.98 72.873 HI00-003

 HI02-0029 20.898 -156.469 Kahului Harbor 2.5 26.160 HI00-002

 HI02-0030 20.937 -156.341 Maliko Bay 0.55 5.168 HI00-001

 HI02-0031 20.790 -156.499 Maalaea Bay 6.78 120.848 HI00-004

 HI02-0032 20.936 -156.269 Uaoa Bay 2.5 26.160 HI00-002

 HI02-0033 20.776 -156.473 Maalaea Bay 6.78 120.848 HI00-004

 HI02-0034 20.764 -156.466 Maalaea Bay 6.78 120.848 HI00-004

 HI02-0035 20.706 -155.994 Pohakuloa Harbor 0.55 5.168 HI00-001

 HI02-0036 20.117 -155.887 Keawanui Bay (Hawaii) 0.55 5.168 HI00-001

 HI02-0037 20.038 -155.839 Kawaihae Bay 6.78 120.848 HI00-004

 HI02-0038 20.017 -155.840 Kawaihae Bay 6.78 120.848 HI00-004

 HI02-0039 19.982 -155.845 Kawaihae Bay 6.78 120.848 HI00-004

 HI02-0040 19.976 -155.838 Kawaihae Bay 6.78 120.848 HI00-004

 HI02-0041 19.943 -155.870 Makaiwa Bay 0.55 5.168 HI00-001

 HI02-0042 19.914 -155.891 Anaehoomalu Bay 2.5 26.160 HI00-002

 HI02-0043 19.811 -156.007 Kua Bay 2.5 26.160 HI00-002

 HI02-0044 19.873 -155.103 Pohakumanu Bay 2.5 26.160 HI00-002

 HI02-0045 19.772 -155.084 Hilo Bay 6.78 120.848 HI00-004

 HI02-0046 19.756 -155.091 Hilo Bay 6.78 120.848 HI00-004

 HI02-0047 19.750 -155.072 Hilo Bay 6.78 120.848 HI00-004

 HI02-0048 19.723 -155.098 Wailuku River 0.55 5.168 HI00-001

 HI02-0049 19.735 -155.079 Hilo Bay 6.78 120.848 HI00-004
EMAP Sta.

No.

Latitude Longitude Estuary or 

 Coastal Bay

Hex

Size

Frame

Area km2

Stratum

14

 HI02-0050 19.728 -155.062 Reeds Bay 0.55 5.168 HI00-001

 HI02-0051 21.378 -158.014 Pearl Harbor 0.13 0.210 Pearl00-010

 HI02-0052 21.373 -158.009 Pearl Harbor 0.13 0.210 Pearl00-010

 HI02-0053 21.383 -157.989 Pearl Harbor 0.07 0.011 Pearl00-011

 HI02-0054 21.372 -158.011 Pearl Harbor 0.86 7.492 Pearl00-012

 HI02-0055 21.359 -158.017 Pearl Harbor 0.86 7.492 Pearl00-012

 HI02-0056 21.379 -157.988 Pearl Harbor 0.86 7.492 Pearl00-012

 HI02-0057 21.359 -158.007 Pearl Harbor 0.86 7.492 Pearl00-012

 HI02-0058 21.369 -157.973 Pearl Harbor 0.86 7.492 Pearl00-012

 HI02-0059 21.379 -157.961 Pearl Harbor 0.86 7.492 Pearl00-012

 HI02-0060 21.349 -157.987 Pearl Harbor 0.86 7.492 Pearl00-012

 HI02-0061 21.359 -157.974 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0062 21.374 -157.952 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0063 21.360 -157.958 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0064 21.375 -157.947 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0065 21.354 -157.961 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0066 21.365 -157.946 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0067 21.373 -157.936 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0068 21.344 -157.966 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0069 21.318 -157.973 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0070 21.328 -157.968 Pearl Harbor 1.24 20.341 Pearl00-013

 HI02-0071 21.288 -157.841 Ala Wai Canal 1.24 20.341 Pearl00-013

 HI02-0072 21.285 -157.841 Ala Wai Harbor 1.24 20.341 Pearl00-013

 HI02-0073 21.293 -157.858 Kewalo Basin 1.24 20.341 Pearl00-013

 HI02-0074 21.318 -157.902 Keehi Lagoon Borrow Pit 1.24 20.341 Pearl00-013

 HI02-0075 21.307 -157.905 Keehi Lagoon 1.24 20.341 Pearl00-013

 HI02-0076 21.316 -157.896 Keehi Lagoon Reef Flat 1.24 20.341 Pearl00-013

 HI02-0077 21.315 -157.898 Keehi Lagoon Reef Flat 1.24 20.341 Pearl00-013

 HI02-0078 21.305 -157.891 Mokauea Isle Reef Flat 1.24 20.341 Pearl00-013

 HI02-0079 21.311 -157.866 Honolulu Harbor 1.24 20.341 Pearl00-013

 HI02-0080 21.309 -157.873 Honolulu Harbor 1.24 20.341 Pearl00-013

 
15

2.2 Data Analysis

Analysis of indicator data was conducted by calculation of cumulative distribution

functions (CDFs), an analysis approach that has been used extensively in other EMAP

coastal studies (Summers et al. 1993, Strobel et al. 1994, Hyland et al. 1996). The

CDFs describe the full distribution of indicator values in relation to their areal extent

across the sampling region of interest. The approximate 95% confidence intervals for

the CDFs also were computed based on estimates of variance. A detailed discussion of

methods for calculation of the CDF’s used in EMAP analyses is provided in Diaz-Ramos

et al. (1996). 

The Horvitz-Thompson ratio estimate of the CDF is given by the formula:

1

1

1 ( ) 1 () ;

( ) = estimated CDF (proportion) for indicator value 

n = number of samples

= the sample response for site i

= the k th CDF response indicator

1, ( )

i k

k

k k

i

k

i

i k

n

n i i

i i

ly x

Fx N

N

Fx x

y

x

y ly x

π

π

∧ ∧

=

∧

=

∧

≤

= =

≤

≤ =

∑

∑

0,

 = selection probability for site i

 = the estimated population size

k

i

x

otherwise

N

π

∧

⎧

⎨

⎩

The selection probability for a site is 1/area of the hexagon, e.g. the hexagon area used

for Hawaii estuaries and bays in the base study in the size class 4.98 km2

 (see Table

2.1-1). When calculating the mean for a variable, the same equation is used, with Yi

replacing the indicator function.
16

The Horvitz-Thompson unbiased estimate of the variance for the ratio estimate is given

by the formula:

2

2

2

1 11

1

11 1

[ ( )] ;

1 , ( ) ( ), ( ) ( )

( ) = estimated CDF (proportion) for indicator value 

1, ( ) 0,

k

i k k jk k

k k

i k

i k

k

n nn

i

i j

i ij i i j ij

n

i j i i

d d d

V Fx

N

N d ly x Fx d ly x Fx

Fx x

y x ly x otherwise

x

π ππ π

π

∧ ∧ = =≠

∧

∧ ∧∧

=

∧

⎛ ⎞

+ − ⎜ ⎟

⎝ ⎠ =

= = ≤− = ≤−

⎧ ≤

≤ = ⎨

⎩

∑ ∑∑

∑

th

th

th

= the k indicator level of interest

 = value of indicator for the i unit sampled

 = inclusion density evaluated at the location

 of the i sample point

 = joint inclusion density evaluat

i

i

ij

y

π

π

th th

ed at the locations

 of the i and j sample points

n = number of units sampled

The joint inclusion probabilities are given by

 π π

π − = ( 1) * i j

ij

n

n
17

When estimating the CDF across several strata, the above estimates for each stratum

must be combined. The equations are

∧ ∧

=

∧

∧

⎛ ⎞ = ⎜ ⎟ ⎝ ⎠ ∑

1

() ()

( ) = estimated CDF

( ) = estimated CDF for stratum i

 = area for stratum i

S = number of strata

A = total area of all strata

k k

k

k

s

i

i

i

i

i

A Fx Fx

A

F x

F x

A

and the variance estimate across strata is

∧ ∧

=

∧

∧

⎛ ⎞ = ⎜ ⎟ ⎝ ⎠ ∑

2

1

 = estimated variance for all strata

 = estimated variance for stratum i

 = area for stratum i

S = number of strata

A = total area of all strata

s

i

i

i

i

i

A V V

A

V

V

A
18

2.3 Indicators

The condition of Hawaii estuarine resources was evaluated by collecting data for a

standard set of core environmental parameters at all stations within the survey (Table

2.3-1). Field procedures followed methods outlined in the US EPA National Coastal

Assessment Field Operations Manual (US EPA, 2001b). The environmental indicators

were similar to those used in previous EMAP estuarine surveys in other regions of the

country (Weisberg et al., 1992; Macauley et al., 1994, 1995; Strobel et al., 1994, 1995;

Hyland et al., 1996, 1998). Indicators were divided into classes representing general

habitat condition (Habitat Indicators), condition of benthic and demersal faunal

resources (Biotic Condition Indicators), and exposure to pollutants (Exposure

Indicators). Habitat indicators describe the general physical and chemical conditions at

the study site, and are often important in providing information used to interpret the

results of biotic condition indicators (e.g., salinity and sediment grain size with regard to

benthic community composition). Biotic condition indicators are measures of the status

of the benthic biological resources in response to site environmental conditions. The

exposure indicators used in this survey quantify the amounts and types of pollutant

materials (metals, hydrocarbons, pesticides) that may be harmful to the biological

resources present. Some indicators may overlap the above categories. For example,

dissolved oxygen is clearly an indicator of habitat condition, but may also be considered

an exposure indicator because of the potentially harmful effects of low dissolved oxygen

levels to many members of the benthic community.

The Hawaii NCA program added several indicators to the NCA core group of

parameters. Dissolved silicate was added because of its importance as a conservative

tracer of groundwater input. Because of the extensive presence of hard bottom habitat

in Hawaiian waters, indicators derived from quadrat and transect assessments of hard

bottom communities were added, such as percent macroalgal and coral cover. In

contrast to other states in the NCA program, bottom trawling was not feasible in Hawaii,

and visual surveys of the entire fish community, rather than measurement of demersal

fishes only, was carried out. Fish biomass estimates were added because they are a

measure of importance in understanding the trophic structure of sample locations. 

Three bacterial indicators were also measured in the Hawaii NCA assessment. 
19

Table 2.3-1. Core environmental indicators for the National Coastal Assessment survey. 

Supplemental indicators measured in Hawaii but not in other states participating in the

National Coastal Assessment are indicated by *. All fish visible in the water column were

censussed visually in Hawaii, as contrasting with trawl samples of demersal species

only for other states.

Habitat Indicators Benthic Condition Indicators

 Salinity Infaunal species composition

 Water depth Infaunal abundance

 pH Infaunal species richness and diversity

 Water temperature (Demersal) fish species composition

 Total suspended solids (TSS) (Demersal) fish abundance, biomass*

 Chlorophyll a concentration (Demersal) fish species richness and

diversity

 Nutrient concentrations (nitrate,

nitrite, ammonium, 

orthophosphate, silicate*)

 External pathological anomalies in fish

 (not assessed)

 Percent light transmission

 (not assessed)

 Percent cover of dominants on

 hard bottom*

 Secchi depth Exposure Indicators

 Percent silt-clay of sediments Dissolved oxygen concentration (DO)

 Percent total organic carbon (TOC)

 in sediments

 Sediment contaminants

 Holothurian tissue contaminants*

 Sediment toxicity (Ampelisca abdita

acute toxicity test)

 Bacteria*
20

2.3.1 Water Measurements

2.3.1.1 Hydrographic Profile

Once a station was located and the vessel was anchored on station, a continuous,

vertical water column profile was carried out using a Hydrolab® H2O Datasonde coupled

to a field display and lap top computer. The instrument measured temperature, depth,

dissolved oxygen, pH and turbidity (NTU). The time of day and tide state were noted for

each station. Methods and procedures used for hydrographic profiling followed

guidance provided in the NCA Quality Assurance Project Plan document (US EPA,

2001).

Secchi depth was determined by using a standard 20-cm diameter black and white

Secchi disc. The disc was lowered to the depth at which it could no longer be discerned,

then was slowly retrieved until it just reappeared. The depth of reappearance was

recorded as Secchi depth (rounded to the nearest 0.1 m). Water clarity at many

stations in the Hawaii base study was such that Secchi depth was equal to the bottom. 

In such cases, the true value of the Secchi depth can not be determined, and such

values were set to missing in the analysis of this parameter. Valid data for Secchi depth

were obtained from only 14 of 50 stations in the base study, although 23 of 30 sites

from the more turbid Oahu estuaries produced valid Secchi depth readings. 

Salinity was determined using an AGE laboratory salinometer (limit of detection =

0.0001 ppt, accuracy = 0.003 ppt). Standard seawater (Copenhagen Water) was used

to calibrate the instrument. Turbidity samples were collected as unfiltered water, and

stored on ice in 125-ml polyethylene bottles until measurements were made. Turbidity

was measured on a Monitek Model 21 nephelometer following procedures as described

in Standard Methods (1985) and data were recorded in NTU.

2.3.1.2 Water Quality Indicators

Once the physical measurements were completed at a station, water samples were

collected at three depths for each station: within 20 cm of the surface, mid-depth in the

water column, and at approximately 1-m above the sea floor, using a 2.2 liter Niskin

sample bottle. Subsamples were withdrawn for nutrients (orthophosphate, nitrate,

nitrite, ammonia), dissolved silica and a bacteria sample. The nutrient samples were

collected in acid-rinsed polyethylene bottles that were triple-rinsed with the sample

water. These samples were held on ice for transportation to the laboratory. The

nutrient samples were filtered through Whatman glass fiber filters (GF/F, 0.7- :m

particle retention) into 125-ml acid-washed, triple-rinsed polyethylene bottles and

immediately placed on ice. Samples were air shipped to the NCA national contract

laboratory for analysis.

All laboratory methods used in processing water column samples followed standard

accepted protocols including those as given in Standard Methods (1985), Strickland and
21

Parsons (1972), Grasshoff (1983). Analyses for the various nutrients were be carried

out by national contract laboratories following standard procedures, protocols and

QA/QC. Water samples were held on ice for no more than 24 hours prior to sample

processing. If a holding time greater than 24 hours was required, nutrient samples were

frozen. The exception was for the silica sample which was refrigerated 

Dissolved oxygen was measured with a Hydrolab® DO sensor on the Hydrolab® H2O 

datasonde.

2.3.2 Sediment Toxicity Testing

2.3.2.1 Sediment Collection for Toxicity Testing, Chemical Analysis and Grain

Size

Composite samples of sediment were collected and analyzed for organic and inorganic

contaminants (i.e., those elements and compounds as given in Table 2.3-3), toxicity

bioassays and determination of physical characteristics. At sample sites that were

within diving depths, the sediment samples were hand-collected by divers in precleaned one-liter Teflon® lined jars with Teflon lined lids, pushing the jar into the

substratum, digging alongside of the jar in the sediment and using the lid to cover the jar

mouth so it could be extracted. At stations where a grab was used the jar was handled

the same way to sample sediment from the grab. Samples for various analyses were

taken within a one-square meter area of substratum and included the sediment from the

surface through the upper 10 cm of material. Samples were chilled and sent within 48

hours of collection by overnight carrier to EPA-approved contract laboratories for

appropriate sample processing and sediment toxicity testing. Holding times for sample

measurements are given in Table 2.3-4. 

2.3.2.2 Amphipod Toxicity Tests

The 10-day, solid-phase toxicity test with the marine amphipod Ampelisca abdita was

used to evaluate potential toxicity of sediments from all sites. Procedures followed the

general guidelines provided in ASTM Protocol E1367-92 (ASTM 1991), the EPA

amphipod sediment toxicity testing manual (US EPA, 1994a), and the EMAP Laboratory

Methods Manual (US EPA 1994b). The Ampelisca test is a 10-d acute toxicity test

which measures the effect of sediment exposure on amphipod survival under static

beaker conditions with aeration. Toxicity tests were conducted with sediment collected

from a one-square meter area within which the sediment for analysis of organic and

trace metal contaminants and other sediment characteristics was also collected. Some

toxicity test sediment was collected several months later than sediment for

contaminants due to problems with the handling of the sediment for toxicity testing.

Ampelisca tests were conducted by an EPA contract laboratory in Pensacola, FL using

amphipods collected from San Pablo Bay in the San Francisco Bay Estuary, CA. All
22

tests were monitored daily during the test for water quality (temperature, salinity,

dissolved oxygen, pH, and total ammonia in the overlying water). Test temperature for

A. abdita ranged from 19 to 21 /C and salinity ranged from 29 to 34 ‰. Test pH at test

initiation ranged from 8 to 8.4 and maximum total ammonia concentration was 1.47

mg/L. The general health of each batch of amphipods was evaluated in a reference

toxicity test (“positive control”) with the reference toxicant cadmium chloride or sodium

dodecyl sulfate (SDS). LC50 values were computed for comparison with other reported

toxicity ranges for the same reference toxicant and test species. 

Treatments for the definitive tests with field samples consisted of five replicates of each

sediment sample (100% sediment) and a negative control consisting of sediment from

the amphipod collection site. A negative control was run with each batch of field

samples. The negative controls provided a basis for comparison to determine statistical

differences in survival in the field sediments and also provided a measure of the

acceptability of final test results. Test results with A. abdita were considered valid if

mean control survival (among the 5 replicates) was $ 90% and survival in no single

control replicate was less than 80%. Test results are reported as control-corrected

values. Mean control survival for A. abdita ranged from 90 to 98% throughout the

various tests, but three control batches had minimum replicate survival < 80%. Test

batches where negative control QA requirements were not met were included in the

CDF analysis. This situation occurred with 24% of the sediments tested. 

A variety of quality control procedures were incorporated to assure acceptability of

amphipod test results and comparability of the data with other studies. As described

above, these provisions included the use of standard ASTM and EMAP protocols,

negative “performance” controls run with reference sediment from the amphipod

collection site, positive controls with reference chemicals to determine the health of the

amphipods, and routine monitoring of water quality variables to identify any departures

from optimum tolerance ranges.

2.3.3 Biotic Condition Indicators

2.3.3.1 Benthic Community Structure

A single sample of approximately 500 cm3

 was collected at each station by SCUBA

divers using jars of 11.2 cm in diameter inserted into the sediment to a depth of

approximately 5 cm. Samples of this volume are adequate because the soft bottom

infauna are both small in size and usually very abundant (Nelson 1986, Swartz et al.

2000). These samples were fixed in their labeled collection containers with buffered

formalin (15%).

All benthic sample processing was carried out at the University of Hawaii. The protocol

for sample handling/processing was as follows: in the laboratory each sediment sample

was handled in a manner identical to the protocol used in the EPA-approved monitoring

program for Honolulu deep ocean sewer outfalls (Swartz et al. 2000). The fixed
23

samples were elutriated using the technique of Sanders et al. (1965). This method

successfully removes from the sediment all organisms that are not heavily calcified. 

The samples were washed several times, and the water from each was poured through

0.5-mm mesh sieves. Polychaetes and other invertebrates retained on the sieve were

transferred to alcohol, stained with rose bengal solution, and stored in 70% ethanol. 

When large carbonate rubble fragments were collected in the sediment samples, the

rubble fragments were carefully washed and visually examined to ensure that any

organisms on the external surfaces were removed. The fragments were then placed in

a nitric acid bath for 24 hours or longer to dissolve the carbonate and to recover

organisms living in burrows. The acid dissolution technique used was modified from the

methods of Brock and Brock (1977), as described in Nelson (1986). 

All specimens were identified to the lowest taxonomic level possible. As a QA/QC

check, all specimens were double checked by a second individual to ascertain that

sorting was complete and identifications were accurate. Any disparity between the

identifications of the two taxonomists was discussed, and discrepancies were resolved

by a sequential process. Additional specimens were examined to compare to the

specimen in question, the literature was searched for additional information, and finally 

international specialists of the genus or family were contacted. Voucher specimens

were submitted to taxonomic specialists for verification when necessary. All specimens

will be archived and maintained for six years by the University of Hawaii. 

Duplicate field collections of benthic samples were conducted at 10 percent of the

sample sites. This sampling strategy is identical to that employed in the ongoing

studies in Mamala Bay carried out as part of the monitoring requirements for Honolulu’s

deep ocean outfalls (Swartz et al. 2000). Comparisons were made between the

duplicate samples. In the case of sites with coralline rubble substratum, two replicate

samples were taken for analysis and served the same purpose. 

Many of the EMAP stations in Hawaii estuaries and bays are located in areas occupied

by coral reefs. The diversity of life forms on coral reefs dictates that a number of

techniques be used to quantify the larger, diurnally active species present. 

Following a visual transect census for fish (Section 2.3.3.2), an enumeration of

epibenthic invertebrates (excluding corals) was undertaken using the same 25 m

transect line as established for fishes. Exposed invertebrates, usually greater than 2 cm

in some dimension, are censussed in the 4 m x 25 m area. This sampling methodology

is quantitative for a few invertebrate groups, e.g., some of the echinoderms (some

echinoids and holothurians), mollusks, and crustaceans. Most coral reef invertebrates

(other than corals) are cryptic or nocturnal in their habits making accurate assessment

of them in areas of topographical complexity very difficult. These factors, coupled with

the fact that the majority of these cryptic invertebrates are small, necessitates the use of

techniques as described for the infaunal component of this study (see also Brock and

Brock 1977). Recognizing these constraints, the macroinvertebrate censusing

technique used here attempts to assess those few species that are diurnally exposed. 
24

Exposed sessile benthic forms such as corals and macrothalloid algae were

quantitatively surveyed by use of quadrats and photographic techniques. Quadrat

sampling consisted of recording benthic organisms, algae and substratum type present

as a percent cover in six, one-meter square frames placed at five-meter intervals along

the transect line established for fish censusing (at 0, 5, 10, 15, 20, and 25 m). At these

same locations a camera mounted on a 0.67 x 1 m frame was also placed and the

substratum was photographed. Photographs provided a permanent record from which

additional coverage estimates of corals and other sessile forms can be made. All

sessile forms were recorded as percent cover. With the macrothalloid algae, emphasis

was placed on those species that are visually dominant, and no attempt was made to

quantitatively assess the multitude of microalgal species that constitute the “algal turf”

so characteristic of many coral reef habitats.

The benthic infaunal data were used to compute total numbers of individuals and total

number of species per 0.0985 m2

 sample. The Shannon-Weaver information diversity

index H! was calculated (log base 2) per 0.0985 m2

 sample. 

Species collected in the infaunal sampling were classified as to origin, using the

following categories: native species, nonindigenous species, cryptogenic species,

indeterminate origin, and unclassified. These assignments were made by the taxonomic

specialists in Hawaii based on their knowledge of components of the fauna, supported

by a variety of publications (Englund et al., 2000; Preskitt et al., 2001).

2.3.3.2 Fish Community Structure

Once a station was located and the vessel appropriately anchored, two SCUBA

equipped divers entered the water. The lead diver was equipped with a slate and pencil

and the assistant carried a 25 m transect line. Fish abundance and diversity is often

related to small-scale topographical relief over short linear distances. A long transect

may bisect a number of topographical features (e.g., cross coral mounds, sand flats,

and algal beds), thus sampling more than one community and increasing the variance in

the resulting data. To alleviate this problem, a short transect (25 m in length) has

proven adequate in sampling many Hawaiian benthic communities (Brock and Norris

1989) and was approved by US EPA Region IX for survey work assessing Hawaiian

ocean sewer outfalls (Brock 1998a, 1999a). Studies have demonstrated that the visual

census technique probably provides the most accurate, nondestructive method

available for the assessment of diurnally-active coral reef fishes (Brock 1982). 

The lead diver located the sample site and commenced to visually enumerate all fishes

present in a 4 x 25 m corridor from the bottom to the surface. Directly behind the lead

diver, the second diver payed out the 25-m transect line. This strategy avoided

underwater activity in the area which could frighten wary fishes. All individuals of all

species were counted and estimates were made on the standard length of each fish

seen. The length was converted to standing crop estimates using linear regression
25

techniques (Richer 1975). The regression coefficients have been developed over 40

years of study in the Hawaiian Islands by a number of authors (Brock 1954, Evans

1974, Brock and Norris 1989) from weight and body length measurements of captured

fishes; for many species, the coefficients have been developed using sample sizes in

excess of a hundred individuals.

2.3.3.3 Holothurian Contaminant Sampling and Chemistry Analyses

Residues of a suite of metals, PCBs, and pesticides were measured in the whole-body

tissues of two species of holothurians (Holothuria atra and H. whitmaei) at 11 stations in

the Hawaii estuaries and bays and 2 stations in the Oahu urbanized estuaries (Table

2.3-2). At each station, the sample team looked for the presence of holothurians in the

immediate vicinity of the sample site (within 10 m). If either of these two species of

holothurians was seen, they were collected. While underwater, holothurians were

placed in zip top plastic bags for transport to the surface. Once on the surface, they

were immediately individually wrapped in tin foil, labeled, placed in a plastic bag with a

second label, sealed and frozen. All samples were sent in a frozen state to the NCA

national contract laboratory for analysis. Guts were not cleared, and thus may have

contained some level of sediments which may have contributed to observed

contaminant levels.

Table 2.3-2. List of stations with collection of holothurians for tissue analysis.

EMAP Station Date Number Collected Species

HI02-0001 18-Jun-02 1 Holothuria whitmaei

HI02-0003 16-Jun-02 1 Holothuria atra

HI02-0012 10-May-02 3 Holothuria atra

HI02-0013 21-May-02 3 Holothuria atra

HI02-0024 1-Apr-02 3 Holothuria atra

HI02-0030 3-Apr-02 2 Holothuria atra

HI02-0033 9-Jun-02 1 Holothuria whitmaei

HI02-0037 7-Jun-02 2 Holothuria atra

HI02-0038 7-Jun-02 2 Holothuria atra

HI02-0040 7-Jun-02 1 Holothuria atra

HI02-0041 8-Jun-02 3 Holothuria whitmaei

HI02-0069 11-Oct-02 2 Holothuria atra

HI02-0078 16-Apr-02 1 Holothuria whitmaei

A total of 13 inorganic metals, 23 polyaromatic hydrocarbons (PAHs), 20

polychlorinated biphenyls (PCBs,), DDT and its primary metabolites, and an additional

14 pesticides (Table 2.3-3) were measured in the holothurian samples. PCB congener

110 was not reported, but the values for PCB77 are likely to actually represent

PCB110/77. Table 2.3-4 summarizes the sample collection, preservation, and holding
26

time requirements for tissue samples. Table 2.4-2 summarizes the analytical methods

used for tissues. The analytical QA/QC procedures for tissue chemistry analysis are

described in Section 2.4. 

2.3.3.4 Bacterial Indicators

Water samples for bacterial analysis, collected at three depths (section 2.3.1.2) were

transferred to sterile 125-ml polyethylene bottles and placed on ice for transport to the

laboratory. Because of the time-sensitive nature of the bacterial samples, upon return

of the survey crew to land (generally within 6 hours), these samples were given to

personnel from the Hawaii Department of Health for immediate on-island sample

processing. On return to the laboratory, enterococci samples were filtered through 0.4 u

sterile membrane filters. Enterococci were measured using techniques described in

“Test Methods for Escherichia coli and Enterococci in Water by the membrane filter

procedure” (EPA 600/4-85/076). Fecal coliforms were measured by the method 9222D,

Fecal Coliform Membrane Filter Procedure (Standard Methods, 1998). Clostridium

perfringens was analyzed by the membrane filtration enumeration method (Bisson and

Cabelli, 1979).

2.3.4 Sediment Chemistry

A total of 15 metals, 20 PCB congeners (PCBs), DDT and its primary metabolites, 13

pesticides, 23 polyaromatic hydrocarbons (PAHs), and total organic carbon (TOC) were

measured in sediments (Table 2.3-3). PCB congener 110 was not reported, but the

values for PCB77 are likely to actually represent PCB110/77. With a few additions, this

suite of compounds is the same as measured in the NOAA NS&T Program.

Sediment for chemical analysis was collected from the top 15 centimeters by hand and

stored in pre-cleaned glass containers with Teflon® lids (see Table 2.3-4). Sediment

samples for chemical analysis were taken from a one-square meter area within which

the sediment for toxicity testing and analysis of other sediment characteristics was also

collected. Approximately 250-300 ml of sediment were collected from each station for

analysis of organic pollutants and another 250-300 ml for analysis of metals and TOC

(Table 2.3-4). Once collected, samples were held in coolers and chilled and once

ashore were sent by overnight carrier to the EPA-approved contract laboratories for

processing. 

Analysis for sediment contaminants was conducted by EPA’s National Contract

Laboratory (NCL). Table 2.4-1 lists the analytical methods used for each compound.

The analytical QA/QC procedures for sediment chemistry analysis are described in

Section 2.4.
27

Table 2.3-3. Compounds analyzed in sediments and holothurian tissues. TOC, antimony, and mangan

only in sediments. Toxaphene was analyzed only in tissues. 

Polyaromatic Hydrocarbons

(PAHs)

PCB Congeners 

(Congener Number and

Compound)

DDT and Other

Chlorinated

Pesticides

Low Molecular Weight PAHs

1-methylnaphthalene1-methylphenanthrene2-methylnaphthalene2,6-dimethylnaphthalene2,3,5-trimethylnaphthaleneAcenaphtheneAcenaphthyleneAnthraceneBiphenylFluoreneNaphthalenePhenanthreneHigh Molecular Weight PAHs

Benz(a)anthraceneBenzo(a)pyreneBenzo(b)fluorantheneBenzo(k)fluorantheneBenzo(g,h,i)peryleneChryseneDibenzothiopheneDibenz(a,h)anthraceneFluorantheneIndeno(1,2,3-c,d)pyrenePyrene

 8: 2,4'-dichlorobiphenyl 18: 2,2',5-trichlorobiphenyl 28: 2,4,4'-trichlorobiphenyl 44: 2,2',3,5'-tetrachlorobiphenyl 52: 2,2',5,5'-tetrachlorobiphenyl 66: 2,3',4,4'-tetrachlorobiphenyl 77: 3,3',4,4'-tetrachlorobiphenyl101: 2,2',4,5,5'-pentachlorobiphenyl105: 2,3,3',4,4'-pentachlorobiphenyl118: 2,3',4,4',5-pentachlorobiphenyl126: 3,3',4,4',5-pentachlorobiphenyl128: 2,2',3,3',4,4'-hexachlorobiphenyl138: 2,2',3,4,4',5'-hexachlorobiphenyl153: 2,2',4,4',5,5'-hexachlorobiphenyl170: 2,2',3,3',4,4',5-heptachlorobiphenyl180: 2,2',3,4,4',5,5'-heptachlorobiphenyl187: 2,2',3,4',5,5',6-heptachlorobiphenyl195: 2,2',3,3',4,4',5,6-octachlorobiphenyl206: 2,2',3,3',4,4',5,5',6-nonachlorobiphenyl209: 2,2'3,3',4,4',5,5',6,6 '-decachlorobiphenyl

DDTs

2,4'-DDD4,4'-DDD2,4'-DDE4,4'-DDE2,4'-DDT4,4'-DDTCyclopentadienes

AldrinDieldrinEndrinChlordanes

Alpha-ChlordaneHeptachlorHeptachlor EpoxideTrans-NonachlorOthersEndosulfan IEndosulfan IIEndosulfan SulfateHexachlorobenzeneLindane (gamma-BHC)MirexToxaphene (tissue only)

M

AAACCCIrLMoMNSSTZMT 
28

Table 2.3-4. Summary of NCA chemistry sample collection, preservation, and holding time requiremen

tissue samples. Modified from Table 5-3 of the Quality Assurance Project Plan 2001-2004 (U.S. EPA, 

Parameter Container Volume Sample Size Sample

Preservation

Max. SamplingHoldingTime

Sediment -Organics

500-ml precleaned glass 250 - 300 ml 300 g (approx.) Freeze (-18o C) 1 year 

Sediment -Metals

125-ml HDPEwide-mouthbottle

100 - 150 ml 75 - 100 g

(approx.)

Freeze (-18o C) 1 year 

Sediment -TOC

Glass jar 100 - 150 ml 30 - 50 ml

(approx.)

Cool (4o C) 6 months 

Tissue Whole

holothurianindividuallywrapped in Al foil, thenplaced inwater-tightplastic bag.

NA NA Freeze (-18o C) 1 year 

a - No EPA criterion exists. Every effort should be made to analyze the sample as soon as possible foor in the case of metals, digestion.
29

2.4 Quality Assurance/ Quality Control of Chemical Analyses

The goals of the NCA QA/QC procedures are to promote the generation of analytical

results achieving the stated objectives and to provide levels of uncertainty in terms of

accuracy and precision of the results. The quality assurance/quality control (QA/QC)

program for the National Coastal Assessment - West program is defined by the

“Environmental Monitoring and Assessment Program (EMAP): National Coastal

Assessment Quality Assurance Project Plan 2001-2004" (US EPA, 2001a), which

established both Methods Quality Objectives (MQOs) and Data Quality Objectives

(DQO). The specific DQOs for the NCA for estimates of current status for indicators of

condition are: "For each indicator of condition, estimate the portion of the resource in

degraded condition within ±10% for the overall system and ±10% for subregions (i.e.,

states) with 90% confidence based on a completed sampling regime." Measurement

quality objectives (MQO) for all NCA field and laboratory parameters are expressed in

terms of accuracy, precision, and completeness goals in the NCA QA Project Plan (US

EPA, 2001a, Table A7-1). These MQOs were established from considerations of

instrument manufacturers’ specifications, scientific experience, and/or historical data. 

However, accuracy and precision goals may not be definable for all parameters due to

the nature of the measurement type (e.g., fish pathology, no expected value). In

general, the quality assurance elements for the National Contract Laboratory (NCL)

included communication of sampling and analytical requirements to the NCL, initial

laboratory capability exercises, program-wide audits of laboratory operations,

documentation of chain-of-custody, and maintaining open lines of communication and

information exchange. 

Details of the general quality assurance procedures to generate sediment and tissue

chemical concentrations with acceptable levels of precision and accuracy are given in

U.S. EPA (2001a). Briefly, a performance-based approach was used, which depending

upon the compound included 1) continuous laboratory evaluation through the use of

Certified Reference Materials (CRMs), Laboratory Control Materials (LCMs), or

Standard Reference Material (SRM); 2) laboratory spiked sample matrices, 3)

laboratory reagent blanks, 4) calibration standards, 5) analytical surrogates, and 6)

laboratory and field replicates. 

One measure of the accuracy of the analytical results is control limit criteria for “relative

accuracy” based on comparing the laboratory’s value to the true or “accepted” values in

CRMs or LCMs (see U.S. EPA, 2001a for details). The requirements for PAHs, PCBs,

and pesticides are that the “Lab’s value should be within ±30% of true value on average

for all analytes; not to exceed ±35% of true value for more than 30% of individual

analytes.” (U.S. EPA 2001a). For metals and other inorganic compounds, the

laboratory's value for each analyte should be within ±20% of the true value of the CRM,

LCM, or SRM. Another measure of accuracy is the percent recovery from matrix

spikes, where a known quantity of the analyte is added to sediment or tissue before

analysis. High percent recoveries indicate that the analytical method and instruments

can adequately quantify the analyte. However, matrix spikes do not evaluate the ability
30

of the extraction method to actually extract the compound bound to the tissue or

sediment. A measure of precision is the “relative percent differences” (RPD) of duplicate

samples, with the objective that the RPD should be <30%. RPDs were determined from

sample replication (if done), matrix spike duplicates, and SRM/CRM/LCM replicates.

Measures of whether the analytical procedure is sufficient to detect the analytes at

environmental levels of concern are the Method Detection Limits (MDLs). An MDL is

“the minimum concentration of a substance that can be measured and reported with

99% confidence that the analyte concentration is greater than zero and is determined

from analysis of a sample in a given matrix containing the analyte." (Code of Federal

Regulations 40 CFR Part 136). Approved laboratories were expected to perform in

general accord with the target MDLs presented for NCA analytes (US EPA, 2001a,

Table A7-2). Because of analytical uncertainties close to the MDL, there is greater

confidence with concentrations above the Reporting Limit (RL), which is the

concentration of a substance in a matrix that can be reliably quantified during routine

laboratory operations. Typically, RLs are 3 to 5 times the MDL. Concentrations

between the MDL and the RL were used in generating the CDF and mean for the

analyte. Any reported values below the MDL were set to 0 and this value was used in

calculating both the CDFs and means. 

A post-analysis assessment of the success of the analytical laboratories in meeting

NCA QA/QC guidelines was conducted by the QA manager of the Western Ecology

Division. The accuracy of results was assessed by determining whether the laboratory

values for SRMs, CRMs, or LCMs were within the NCA guidelines for sediment and

tissues, while precision was assessed by the RPDs. An overview of the QA/QC results

is given below.

2.4.1 Metals in Sediments

Table 2.4-1 lists analytical method for each of the metals in the sediment samples. The

analytical methods are those used in the NOAA NS&T Program (Lauenstein and

Cantillo,1993) or documented in the EMAP Laboratory Methods Manual (U.S. EPA,

1994b). Table 2.4-1 also lists the units and method detection limits (MDL) for each

metal. The laboratory MDL met or were below the target MDL for all the sediment

metals. Reporting limits (RLs) were not reported for the metals, but as mentioned they

are typically 3 to 5 times the MDL. 

The percent recovery from certified/standard materials, recovery from matrix spikes,

and the average RPD for non-zero sample duplicates and matrix spikes for the

sediment metals are summarized in Table 2.4-3. No defined sediment

certified/standard reference materials were reported for metals, and thus this aspect of

the DQOs can not be directly assessed. However, the matrix spike samples had

sufficiently low concentrations that the sediment samples were likely to have been

sufficiently accurate for the project goals. One caveat is that the laboratory reported QC

results from the batches containing only 26 of 85 stations. Averaged across all metals,
31

the recovery for sediment metals from matrix spikes met the DQO of being within +50%

of the true values. Exceptions were aluminum, which deviated by 157% from the matrix

spike, and iron, which deviated by 79%. On average, the RPDs for metals were <30%. 

Manganese slightly exceeded the criterion (33%), while aluminum and iron failed the

DQO with RPDs of 87% and 75%, respectively.

2.4.2 Organics in Sediments

Table 2.4-1 lists analytical method for each of the organic compounds in the sediment

samples. The analytical methods are those used in the NOAA NS&T Program

(Lauenstein and Cantillo, 1993) or documented in the EMAP Laboratory Methods

Manual (U.S. EPA, 1994b). Table 2.4-1 also lists the units, method detection limit

(MDL), and reporting limits (RL) for each organic compound. The laboratory MDLs met

or were below the target MDL for all of the sediment organics.

The percent recovery from certified/standard materials, recovery from matrix spikes,

and the average RPD for non-zero sample duplicates and matrix spikes are

summarized in Table 2.4-3. No defined sediment reference materials were reported for

organics, and thus this aspect of the DQOs can not be directly assessed. However, the

matrix spike samples had sufficiently low concentrations that the sediment samples

were likely to have been sufficiently accurate for the project goals. One caveat is that

the laboratory reported QC results from the batches containing only 26 of 85 stations.

Averaged across all compounds within a class, the matrix spikes were within +50% of

the true values for PAHs, PCBs, and pesticides. Individual compounds where the

average percent difference among matrix spikes was >50% included pyrene (51%),

PCB 18 (191%), Endosulfan I (61%), and Endosulfan II (94%). The average RPDs for

all sediment analytes met the DQO of duplicates being within 30%. The individual

compounds with >30% difference among matrix spike duplicates included 2-

methylnaphthalene (43%), PCB 18 (138%), Endosulfan I (36%) and Endosulfan II

(67%).

2.4.3 Chemical Residues in Tissues

Table 2.4-2 lists analytical method for each of the metals and organic compounds

measured in tissue samples. The analytical methods are those used in the NOAA

NS&T Program (Lauenstein and Cantillo, 1993) or documented in the EMAP Laboratory

Methods Manual (U.S. EPA, 1994b). Table 2.4-2 also lists the units, method detection

limit (MDL), and reporting limits (RL) for each metal or organic compound. The

laboratory MDLs were met or were below the target MDL for all of the compounds

except for tin.

The percent recovery from certified/standard materials, recovery from matrix spikes,

and the average RPD for non-zero sample duplicates and matrix spikes for tissue

metals and organics are summarized in Table 2.4-3. Spiked cod fillets from NSI were
32

used as a laboratory control material. The percent recovery for the metals in these cod

fillets for the six metals analyzed were all within +30% of the true value. The percent

recovery for the metals in the matrix spikes with the cod tissue met the criterion of being

with +50% of the true value. No sample duplicates or matrix spike duplicates were

reported, so it is not possible to assess the RPD for tissue metals.

Recovery of PAHs, PCBs, and the pesticides was poor in the cod laboratory control

material, exceeding the DQO of being within +30% of the true value for every individual

compound. The matrix spikes for all PCBs met the DQO of being within +50% of the

true values, although PCB 126 exceeded the criterion. In comparison, the average for

both PAHs and pesticides exceeded the DQO for matrix spikes, with most individual

compounds exceeding +50% criterion. No non-zero duplicate tissue results were

reported, so it is not possible to assess the RPD for tissue organics. In summary, the

organic tissue residue data are suspect, and the lack of detection of a compound does

not necessarily mean that the compound was not present. 
33

Table 2.4-1. Units, method detection limits (MDL), reporting limits (RL), analytical

method, and responsible laboratory for sediment chemistry. Target MDLs are from the

National Coastal Assessment (US EPA, 2001a). NR = not reported. NA = not

applicable.

Analyte Units

(dry wt.)

Target

MDL

MDL/RL Method Laboratory

Aluminum :g/g 1500 28/NR ICPOES ERI

Antimony :g/g 0.2 0.1/NR ICPMS ERI

Arsenic :g/g 1.5 0.1/NR GFAAS ERI

Cadmium :g/g 0.05 0.05/NR ICPMS ERI

Chromium :g/g 5.0 0.7/NR ICPOES ERI

Copper :g/g 5.0 0.7/NR ICPOES ERI

Iron :g/g 500 14/NR ICPOES ERI

Lead :g/g 1.0 0.1/NR ICPMS ERI

Manganese :g/g 1.0 0.7/NR ICPOES ERI

Mercury :g/g 0.01 0.01/NR CVAA ERI

Nickel :g/g 1.0 0.7/NR ICPOES ERI

Selenium :g/g 0.1 0.1/NR ICPMS ERI

Silver :g/g 0.05 0.01/NR ICPMS ERI

Tin :g/g 0.1 0.1/NR ICPMS ERI

Zinc :g/g 2.0 1.4/NR ICPOES ERI

PAHs (23 compounds) ng/g 10.0 4.97/16.79 GCMS ERI

PCB (20 congeners) ng/g 1.0 0.18/0.89 GCECD ERI

DDT, DDD, and DDE ng/g 1.0 0.18/0.89 GCECD ERI

Aldrin ng/g 1.0 0.18/0.89 GCECD ERI

Alpha-Chlordane ng/g 1.0 0.18/0.89 GCECD ERI

Dieldrin ng/g 1.0 0.18/0.89 GCECD ERI

Endosulfan I ng/g 1.0 0.18/0.89 GCECD ERI

Endosulfan II ng/g 1.0 0.18/0.89 GCECD ERI

Endosulfan Sulfate ng/g 1.0 0.18/0.89 GCECD ERI

Endrin ng/g 1.0 0.18/0.89 GCECD ERI

Heptachlor ng/g 1.0 0.18/0.89 GCECD ERI
Analyte Units

(dry wt.)

Target

MDL

MDL/RL Method Laboratory

34

Heptachlor Epoxide ng/g 1.0 0.18/0.89 GCECD ERI

Hexachlorobenzene ng/g 1.0 0.18/0.89 GCECD ERI

Lindane (gamma-BHC) ng/g 1.0 0.18/0.89 GCECD ERI

Mirex ng/g 1.0 0.18/0.89 GCECD ERI

Trans-Nonachlor ng/g 1.0 0.18/0.89 GCECD ERI

TOC percent NA NR SEDM-TC ERI

Percent fines percent NA NR Gravimetric ERI

Analytical Methods: GCMS = gas chromatography/mass spectroscopy; ICPOES =

Inductively Coupled Plasma Optical Emission Spectroscopy; ICPMS = Inductively

Coupled Plasma-Mass Spectrometry, GFAAS = graphite furnace atomic absorption

spectrometry; CVAA = cold vapor atomic adsorption, GCECD = gas chromatography

and electron capture detection, SEDM-TC = organic and inorganic analysis by EPA

method 440. 

Analytical Laboratories: ERI = Environmental Research Institute, Univ. of Connecticut.
35

Table 2.4-2. Units, method detection limits (MDL), reporting limits (RL), analytical

method, and responsible laboratory for tissue chemistry. Target MDLs are from the

National Coastal Assessment (US EPA, 2001a, Table A7-2). NA = not applicable.

Analyte Units

(wet wt.)

Target 

MDL

MDL/RL Method Laboratory

Aluminum :g/g 10.0 0.41/9.3 ICPAES GPL

Arsenic :g/g 2.0 0.13/0.93 GFAA GPL

Cadmium :g/g 0.2 0.01/0.27 ICPMS GPL

Chromium :g/g 0.1 0.04/0.23 ICPAES GPL

Copper :g/g 5.0 0.05/0.36 ICPAES GPL

Iron :g/g 50.0 1.16/6.9 ICPAES GPL

Lead :g/g 0.1 0.04/0.46 ICPMS GPL

Mercury :g/g 0.01 0.009/0.018 CVAA GPL

Nickel :g/g 1.0 0.05/0.36 ICPAES GPL

Selenium :g/g 0.5 0.13/0.93 ICPMS GPL

Silver :g/g 0.05 0.04/0.14 ICPMS GPL

Tin :g/g 0.05 0.14/1.1 ICPMS GPL

Zinc :g/g 50.0 0.43/2.3 ICPAES GPL

PAHs (average23

compounds)

ng/g 20.0 6.2/20 GCMS GPL

PCB (20 congeners) ng/g 2.0 0.1/2 GCMS GPL

DDT, DDD, and DDE ng/g 2.0 0.01/1 GCECD GPL 

Aldrin ng/g 2.0 0.01/1 GCECD GPL

Alpha-Chlordane ng/g 2.0 0.01/1 GCECD GPL 

Dieldrin ng/g 2.0 0.01/1 GCECD GPL

Endosulfan I ng/g 2.0 0.01/1 GCECD GPL

Endosulfan II ng/g 2.0 0.01/1 GCECD GPL 

Endosulfan Sulfate ng/g 2.0 0.01/1 GCECD GPL 

Endrin ng/g 2.0 0.01/1 GCECD GPL

Heptachlor ng/g 2.0 0.01/1 GCECD GPL

Heptachlor Epoxide ng/g 2.0 0.01/1 GCECD GPL

Hexachlorobenzene ng/g 2.0 0.01/1 GCECD GPL

Lindane (gamma-BHC) ng/g 2.0 0.01/1 GCECD GPL 
Analyte Units

(wet wt.)

Target 

MDL

MDL/RL Method Laboratory

36

Mirex ng/g 2.0 0.01/1 GCECD GPL

Toxaphene ng/g 2.0 0.01/50 GCMS GPL 

Trans-Nonachlor ng/g 2.0 0.01/1 GCECD GPL

Analytical Methods: Analytical Methods: GCMS = gas chromatography/mass

spectroscopy, ICPMS = Inductively Coupled Plasma-Mass Spectrometry, GFAA =

graphite furnace atomic absorption spectrometry, ICPAES = Inductively-Coupled

Plasma Atomic Emission Spectrometer, CVAA = cold vapor atomic adsorption, GCECD

= gas chromatography and electron capture detection,

Analytical Laboratories: GPL = GPL Laboratories.
37

Table 2.4-3. Summary of performance of analytical laboratories for Hawaii samples

with regard to data quality objectives (DQOs) for analysis of reference materials, matrix

spike recoveries, and relative percent differences (RPD) of duplicates. MS = matrix

spike, SRM = Standard Reference Material, CRM = Certified Reference Material, LCM =

Laboratory Control Material, None = the QC material was not analyzed or QC activity

not performed. NA = not applicable. DQOs for organics for recovery from reference

materials is +30% for organics and +20% for metals. 

Analyte

(#

analytes)

Material Average met

DQO for

comparison

to standard?

If No, % difference from true

value / 

(# analytes reported) / 

type of reference material

Matrix spike

recovery within

50%-150% and (%

difference from

matrix spike)

Average RFD of

sample replicates

and matrix spike

duplicates <30% 

Metals Sediment None None Yes (33%) Yes

(15) Tissue Yes NA / 7 / LCM Yes (5%) None

PAHs

(23)

Sediment

Tissue

None

No

None

73% / 16 / LCM

Yes (38%)

No (71%)

Yes

Yes

PCBs Sediment None None Yes (17%) Yes

(21) Tissue No 72% / 8 / LCM Yes (35%) Yes

Pestici

des

Sediment None None Yes (20%) Yes

(20) Tissue No 73% / 13 / LCM No (71%) Yes
38

2.5 Data management

Data management for the Hawaii stations sampled in 2002 is a component of the

overall National Coastal Assessment - West Information Management Program. The

Information Management System is based on a centralized data storage model using

standardized data transfer protocols (SDTP) for data exchange among program

participants. The data are submitted to the NCA - West Information Manager (IM)

located at the U.S. EPA laboratory in Newport, Oregon, for entry into the relational

database (Microsoft Access). 

The data flow consists of interactions among four levels. Field crew leaders and

laboratory supervisors are responsible for compiling data generated by their

organizations and for entering the data into one or more of the SDTP tables. The State

Information Management (IM) Coordinator is responsible for compiling all data

generated within a state into a unified state database. The NCA - West IM Coordinator

is responsible for working with State Coordinators to develop the SDTP, and for creation

and management of the centralized West Coast EMAP database. The EMAP IM

Coordinator, located at the Atlantic Ecology Division of EPA at Narragansett, Rhode

Island, is responsible for accepting data from Western EMAP, for placing it in the

national EMAP database, and for transferring it to other EPA databases, such as

STORET.

Once all data tables of a particular data type (e.g. all tables containing fish data) were

certified by the NCA - West IM Coordinator, integrated multi-state data tables were

provided to the Western EMAP Quality Assurance Coordinator (QAC). The QAC

reviewed the data with respect to scientific content. Necessary corrections resulting

from this review process were returned to the NCA - West IM Coordinator who was

responsible for working with the State IM Coordinator to make necessary changes. 

Following certification of all portions of the data by the QAC, the NCA - West IM

Coordinator submitted the integrated multi-state data set to the EMAP IM Coordinator

who is the point of contact for data requests about the integrated data set.

Details of the Western EMAP Information Management process are provided in Cooper

(2000). The structure of each of the relational data base tables and supporting database

look-up tables used by the states to submit data to the NCA - West IM Coordinator are

provided in this document.

2.6 Unsamplable Area

All stations in Hawaii were sampled except station HI02-0065. This station was located

within the East Loch of the Pearl Harbor Naval base, and access to this location was

denied by the U.S. Navy due to classified (military) activities occurring in the area during

the period of time that the EMAP field survey team was present in the harbor. No

sediment was obtained at stations HI02-0004, HI02-0012, HI02-0030, HI02-0032, and
39

HI02-0037. Underwater visual surveys could not be conducted at many stations due to

poor water visibility, particularly those in the Oahu urbanized harbors.

2.7 Lessons Learned

The EMAP survey of the Hawaiian Islands utilized several approaches which were new

to the National Coastal Assessment program. Some of the approaches proved useful,

and others were less successful. The sampling of holothurian tissue was attempted as a

substitute for the usual analysis of fish tissue for chemical contaminants. Specimens

were obtained at only 13 stations, demonstrating that this taxon was much less widely

distributed than anticipated. The analytical laboratory also had considerable difficulty

with the tissue matrix, and the recovery of target analytes from the holothurian tissues

was less than desired in some cases. Alternate approaches to collection of tissue for

contaminant analysis should be explored.

Visual survey methods for fish community analyses were highly effective wherever

water conditions permitted visual transects to be conducted. However, surveys could

only be conducted at 38 of the 79 (48%) sites, and tended to be unsuccessful in the

more turbid, estuarine conditions. Given the heterogeneous nature of the bottom types

in Hawaii which precluded general use of trawls, this limitation on fish community

assessment remains problematic.

The Hawaii field team did not collect PAR data in the water column, but did collect

Secchi depth measurements. In many NCA assessments, Secchi depth has proved an

acceptable indicator of water clarity. In Hawaii, Secchi depth was not a useful indicator

for water quality because in the very clear waters typical of many areas, the Secchi disc

was still visible at the bottom, and thus the true Secchi depth could not be measured. 

Secchi depth tended to be measurable at more turbid sites, thus introducing a bias into

the data for Secchi depth as a measure of water clarity. It is therefore critical that PAR

measurements be obtained in order to develop a useful indicator of water clarity for the

Hawaiian Islands.
40

3.0 Indicator Results

Presentation of results for individual indicators utilizes cumulative distribution functions

(CDFs) representing the percentage area of the sample frame associated with given

values of the indicator. In the case of some parameters, area estimates associated with

benchmark values of the indicator are presented, e.g. sediment contaminants are

referred to values of the Effects Range Median (ERM) or Effects Range Low (ERL) if

these values are available (see Section 3.2.2). In other cases where there are no

relevant benchmarks, the area estimates associated with statistical percentiles (50th,

90th) are presented. The state of Hawaii has water quality criteria for marine waters for

several indicators measured by EMAP (see (Section 11-54-8, Hawaii Department of

Health, Amendment and Compilation of Chapter 11-54, Hawaii Administrative Rules,

August 31, 2004). However, these criteria are expressed as geometric means of

multiple sample events, and are different for specific estuaries, bays and coastal

regions. The EMAP sampling frame was not designed with these specific water quality

classes, and samples were taken at only one date per station. Therefore, we have

chosen to present water quality indicators in reference to statistical percentiles. 

3.1 Habitat Indicators

3.1.1 Water Depth at Sample Sites

Bottom depth for the 50 stations sampled in Hawaii estuaries and bays ranged from

0.25 m to 21.3 m. The 50th percentile of area of the Hawaii estuaries and coastal bays

sampled had a water depth of 6.1 m while the 90th percentile had a depth of 14.8 m

(Figure 3.1 -1). Bottom depth for sample sites in the Oahu urbanized estuaries ranged

between 0.25 m and 16.5 m. The 50th percentile of area of the Oahu urbanized

estuaries had a bottom depth of 6.7 m while the 90th percentile had a depth of

approximately 13.2 m (Figure 3.1-2).

3.1.2 Salinity

Salinity in the bottom water for the 50 stations sampled in Hawaii estuaries and bays

ranged only from 20.9 psu to 37.2 psu. The 50th percentile of area of the Hawaii

estuaries and coastal bays sampled had a bottom salinity of 35.2 psu, while the 90th

percentile had a salinity of 35.7 psu (Figure 3.1-3). Nearly the entire area (99.6%) of

the Hawaii estuaries would be classified as euhaline ($30 psu) based on the EMAP

sampling of bottom waters. The sites in the Oahu urbanized estuaries had bottom

salinities in a similar range, 30.6 psu to 36.5 psu (Figure 3.1-4). The 50th percentile of

area of the Oahu urbanized estuaries had a bottom salinity of 35.7 psu while the 90th

percentile had a value of 36.2 psu. Only approximately 8% of the area of the Oahu

urbanized estuaries had salinity less than or equal to 28.4 psu. In interpreting these

results, it is important to recognize that salinity can vary both tidally and seasonally, as

well as with depth in the water column, and that these single measurements are

"snapshots" during the sampling events. 
41

3.1.3 Water Temperature

Temperature in the bottom water for the 50 stations sampled in Hawaii estuaries and

bays ranged from 23.9 °C to 27.5 °C (Figure 3.1-5). The range of surface water

temperatures was virtually identical to that for bottom water temperatures (23.9 °C to

27.6 °C). Within a station, the maximum temperature difference between surface and

bottom waters was 2.5 °C. The Oahu urbanized estuaries showed a similar range of

bottom (25.4 °C to 27.9 °C) (Figure 3.1-6) and surface water temperatures (24.6 °C to

29.9 °C). These temperatures are representative of summer conditions in the region. 

The 50th percentile of area of the Hawaii estuaries and coastal bays sampled had a

bottom temperature of 23.9 °C, while the 90th percentile had a salinity of 23.9 °C (Figure

3.1-5). The 50th percentile of area of the Oahu urbanized estuaries had a bottom

temperature of 25.7 °C while the 90th percentile had a value of 26.7 °C. 

3.1.4 pH

The pH of bottom waters for the 50 stations sampled in Hawaii estuaries and bays

ranged from 7.7 to 8.2 (Figure 3.1-7). The Oahu urbanized estuaries showed a very

similar range of bottom water pH from 7.4 to 8.1 (Figure 3.1-8). The range for pH in

surface water samples was virtually identical to that for bottom waters (7.6 - 8.2). The

50th percentile of area of the Hawaii estuaries and coastal bays sampled had a pH of

8.07 while the 90th percentile had a pH of 8.1 (Figure 3.1-7). The 50th percentile of area

of the Oahu urbanized estuaries had a bottom water pH of 7.97 while the 90th percentile

had a pH of 8.1 (Figure 3.1-8).

3.1.5 Sediment Characteristics

The percent silt-clay of sediments ranged from 0% to 92.5% at the 45 stations sampled

in Hawaii estuaries and bays from which soft sediment samples could be obtained

(Figure 3.1-9). About 73% of the area of the Hawaii estuaries and bays had sediments

composed of sands (<20% silt-clay), about 21% was composed of intermediate muddy

sands (20-80% silt-clay), and about 6% was composed of muds (>80% silt-clay). The

Oahu urbanized estuaries (29 stations) had a greater proportion of area characterized

by muds (62%), and less area characterized by sands (15%) or intermediate muddy

sands (23%) (Figure 3.1-10). The 50th percentile of area of the Hawaii estuaries and

coastal bays sampled had a percent silt-clay of sediments of 3.1%, while the 90th

percentile had a percent silt-clay of 53% (Figure 3.1-9). The 50th percentile of area of

the Oahu urbanized estuaries had a percent silt-clay of 83.9%, while the 90th percentile

had a percent silt-clay of 96.5% (Figure 3.1-10).

Percent total organic carbon (TOC) in sediments ranged from 0.05% to 2.47% at the 31

stations within the base study from which soft sediment samples for TOC analysis were 

obtained (Figure 3.1-11). The 50th percentile of area of the Hawaii estuaries and coastal

bays sampled had a sediment TOC level of 0.19%, while the 90th percentile had a

sediment TOC level of 0.96%. The range of TOC values was 0.19% to 3.86% at the 18
42

stations within Oahu urbanized estuaries for which TOC samples were analyzed (Figure

3.1-12). The 50th percentile of area of the Oahu urbanized estuaries had a sediment

TOC level of 1.8%, while the 90th percentile had a sediment TOC level of 2.1%, which is

expected given the more depositional character of these harbors.

3.1.6 Water Quality Parameters

Water quality parameters are presented as water column mean values based on the

concentration averaged over the surface, mid-water, and bottom water samples.

Chlorophyll a

The average water column concentration of chlorophyll a for the 50 stations sampled in

Hawaii estuaries and bays ranged from 0.1 to 8.7 :g L-1 (Figure 3.1-13) . The 50th

percentile of area of the Hawaii estuaries and coastal bays sampled had a chlorophyll a

concentration of 0.34 :g L-1, while the 90th percentile had a chlorophyll a concentration

of 1.2 :g L-1. Chlorophyll a concentration within the Oahu urbanized estuaries ranged

between 0.1 and 5.6 :g L-1. The 50th percentile of area of the Oahu urbanized estuaries

had a chlorophyll a concentration of 0.8 :g L-1, while the 90th percentile of area had a

chlorophyll a concentration of approximately 2.8 :g L-1 (Figure 3.1-14).

Nutrients

The average water column concentration of nitrate in Hawaii estuaries and bays ranged

from 0 to 212 :g L-1 (Figure 3.1-15). The 50th percentile of area of the Hawaii estuaries

and coastal bays sampled had a nitrate concentration of 2.5 :g L-1, with the 90th

percentile of area characterized by a nitrate concentration of 11 :g L-1. Less than 5% of

estuarine and coastal bay area exceeded concentrations of 14 :g L-1. Nitrate

concentration within the Oahu urbanized estuaries ranged between 0 and 68.7 :g L-1.

The 50th percentile of area of the Oahu urbanized estuaries had a nitrate concentration

of 3.2 :g L-1, with the 90th percentile of area characterized by a nitrate concentration of

12 :g L-1 (Figure 3.1-16). 

The average water column concentration of nitrite in Hawaii estuaries and bays ranged

from 0 to 7 :g L-1 (Figure 3.1-17). The 50th percentile of area of the Hawaii estuaries

and coastal bays sampled had a nitrite concentration of 0 :g L-1, with the 90th percentile

of total area characterized by a nitrite concentration of 3.6 :g L-1. Nitrite concentration

within the Oahu urbanized estuaries was within the similar range of 0 to 5 :g L-1. The

50th percentile of area of the Oahu urbanized estuaries had a nitrite concentration of 0

:g L-1, with the 90th percentile of total area characterized by a nitrite concentration of 3.4

:g L-1 (Figure 3.1-18).

The average water column concentration of ammonium in Hawaii estuaries and bays

ranged from 2.5 to 77.6 :g L-1 (Figure 3.1-19). The 50th percentile of area of the Hawaii

estuaries and coastal bays sampled had an ammonium concentration of 31.7 :g L-1,
43

with the 90th percentile of total estuarine area characterized by an ammonium

concentration of 57 :g L-1. Ammonium concentration within the Oahu urbanized

estuaries ranged from 0 to 34 :g L-1. The 50th percentile of area of the Oahu urbanized

estuaries had an ammonium concentration of 10 :g L-1, with the 90th percentile of total

area characterized by an ammonium concentration of 25.7 :g L-1 (Figure 3.1-20). 

The average water column concentration of total dissolved inorganic nitrogen (nitrogen

as nitrate + nitrite + ammonium) in Hawaii estuaries and coastal bays ranged from 2.5

to 284 :g L-1 (Figure 3.1-21). The 50th percentile of area of the Hawaii estuaries and

coastal bays sampled had a total nitrogen concentration of 36.5 :g L-1, with the 90th

percentile of total area characterized by a total nitrogen concentration of 66.5 :g L-1.

Total nitrogen concentration within the Oahu urbanized estuaries ranged from 0 to 97.7

:g L-1. The 50th percentile of area of the Oahu urbanized estuaries had a total nitrogen

concentration of 19 :g L-1, with the 90th percentile characterized by a total nitrogen

concentration of 35 :g L-1 (Figure 3.1-22).

The average water column concentration of orthophosphate in Hawaii estuaries and

coastal bays ranged from 0 to 33 :g L-1 (Figure 3.1-23). The 50th percentile of area of

the Hawaii estuaries and coastal bays sampled had an orthophosphate concentration of

4.4 :g L-1, with the 90th percentile of total estuarine area characterized by a

concentration of 7.1 :g L-1. Orthophosphate concentration within the Oahu urbanized

estuaries ranged between 0 and 396.7 :g L-1. The 50th percentile of area of the Oahu

urbanized estuaries had an orthophosphate concentration of 2.7 :g L-1, with the 90th

percentile of area characterized by a concentration of 6.4 :g L-1 (Figure 3.1-24).

The ratio of total dissolved inorganic nitrogen (nitrogen as nitrate + nitrite + ammonium)

concentration to total orthophosphate concentration was calculated as an indicator of

which nutrient may be controlling primary production. A ratio above 16 is generally

considered indicative of phosphorus limitation, and a ratio below 16 is considered

indicative of nitrogen limitation (Geider and La Roche, 2002). The N/P ratio ranged

from 2.4 to 36.4, across the 49 stations in Hawaii estuaries and bays where sufficient

measurements were collected to compute the ratio (Figure 3.1-25). Approximately 40%

of estuarine area had N/P values # 16. The 50th percentile of area of the Hawaii

estuaries and coastal bays sampled had a ratio of 20.7, while the 90th percentile of area

had a ratio of 27. The N/P ratio ranged from 0 to 64.6, across the 29 stations in Oahu

urbanized estuaries where sufficient measurements were collected to compute the ratio

(Figure 3.1-26). Approximately 74% of estuarine area in Oahu urbanized estuaries had

N/P values # 16. The 50th percentile of area of the Oahu urbanized estuaries had a

ratio of 7.8, while the 90th percentile of area had a ratio of 25. The long right hand tail of

the CDF was due to one station representing 8% of area with an N/P ratio of 64.6. 

The average water column concentration of silicate in Hawaii estuaries and coastal bays

ranged from 57.3 to 14,710 :g L-1 (Figure 3.1-27). The 50th percentile of area of the

Hawaii estuaries and coastal bays sampled had a silicate concentration of 230 :g L-1,

with the 90th percentile of area characterized by a concentration of 1468 :g L-1 (Figure
44

3.1-27). Silicate concentration within the Oahu urbanized estuaries ranged between 70

and 10,090 :g L-1. The 50th percentile of area of the Oahu urbanized estuaries had a

silicate concentration of 839 :g L-1, with the 90th percentile of area characterized by a

concentration of 2988 :g L-1 (Figure 3.1-28).

Turbidity

The bottom turbidity in Hawaii estuaries and coastal bays ranged from 0 to 1423 NTU. 

 The 50th percentile of area of the Hawaii estuaries and coastal bays sampled had a

bottom turbidity of 0.8 NTU, with the 90th percentile of area characterized by a bottom

turbidity of 204 NTU (Figure 3.1-29). Bottom turbidity within the Oahu urbanized

estuaries ranged from 1.7 to 1746 NTU. The 50th percentile of area of the Oahu

urbanized estuaries had a bottom turbidity of 340 NTU, with the 90th percentile of area

characterized by a bottom turbidity of 1065 NTU (Figure 3.1-30). 

The surface turbidity ranged from 0 to 355 NTU. The 50th percentile of area of the

Hawaii estuaries and coastal bays sampled had a surface turbidity of 0.09 NTU, with the

90th percentile of area characterized by a turbidity level of only 3.4 NTU (Figure 3.1-31). 

The surface turbidity within the Oahu urbanized estuaries ranged from 0 to 970 NTU.

The 50th percentile of area of the Oahu urbanized estuaries had a surface turbidity of

3.8 NTU, with the 90th percentile of area characterized by a turbidity level of 75 NTU

(Figure 3.1-32). 

Secchi Depth

The Secchi depth of the water column in Hawaii estuaries and bays ranged from 0.8 to

9.4 m at the 14 sites where measurements were obtained. Because the Secchi depth

was equal to the bottom depth at many sites, information from this CDF should be

interpreted cautiously (Figure 3.1-33), and percentiles are not presented. Sites with

Secchi depths included in the analysis will tend to be either those that were deeper, or

those that were more turbid. The Secchi depth within the Oahu urbanized estuaries

ranged from 0.6 to 6.9 m at the 23 sites where measurements were obtained. The 50th

percentile of area of the Oahu urbanized estuaries had a Secchi depth of 3.2 m, with the

90th percentile of area represented by a value of 5.5 m (Fig. 3.1-34). 

3.1.7 Water Column Stratification

As an indicator of water column stratification, an index was calculated with temperature

and salinity data. The index ()Ft) was the difference between the computed bottom and

surface Ft values, where Ft is the density of a parcel of water with a given salinity and

temperature relative to atmospheric pressure. 

The )Ft index for stations from Hawaii estuaries and bays had values ranging from 

-0.07 to +10.1. Approximately 4% of the area of Hawaii estuaries and bays showed )Ft

index values < 0, indicating bottom waters less dense than surface waters (Figure 3.1-
45

35). Approximately 18% of the area of Hawaii estuaries and bays had )Ft index values

$ 2, indicating strong stratification. The )Ft index for stations from Hawaii estuaries and

bays had values ranging from -1.1 to +21.2. Approximately 11% of the area of Oahu

urbanized estuaries showed )Ft

 index values < 0, indicating bottom waters less dense

than surface waters (Figure 3.1-36). Approximately 65% of estuarine area had )Ft

index values $ 2, indicating strong vertical stratification.

The limited indication of strong water column stratification within the Hawaii estuaries

and coastal bays indicates water bodies that are well mixed. The Oahu urbanized

estuaries show a much higher indication of strong vertical stratification.
46

Depth 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 5 10 15 20

m

Cumulative Percent 

Area

Cumulative Percent

95% Confidence Interval

Depth 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 5 10 15 20 25

m

Cumulative Percent 

Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-1. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. bottom

depth.

Figure 3.1-2. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. bottom

depth.
47

Bottom Salinity 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 5 10 15 20 25 30 35 40

Salinity (psu)

Cumulative Percent 

Area

Cumulative Percent

95% Confidence Interval

Bottom Salinity 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 5 10 15 20 25 30 35 40

Salinity (psu)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-3. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. salinity of

bottom waters.

Figure 3.1-4. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. salinity of

bottom waters.
48

Bottom Temperature 

Oahu Urbanized Estuaries

0

20

40

60

80

100

23.5 24 24.5 25 25.5 26 26.5 27 27.5 28

Temperature (0C)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Bottom Temperature 

Hawaii Estuaries and Bays

0

20

40

60

80

100

23.5 24 24.5 25 25.5 26 26.5 27 27.5 28

Temperature (0C)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-5. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. temperature

of bottom waters.

Figure 3.1-6. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. temperature

in bottom waters.
49

Bottom pH 

Hawaii Estuaries and Bays

0

20

40

60

80

100

7.3 7.5 7.7 7.9 8.1 8.3

pH

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Bottom pH 

Oahu Urbanized Estuaries 

0

20

40

60

80

100

7.3 7.5 7.7 7.9 8.1 8.3

pH

Cumulative Percent Area

Cumulative Percent

95% Confidence interval

Figure 3.1-7. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. pH in

bottom waters.

Figure 3.1-8. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. pH in

bottom waters.
50

Percent Silt-Clay Content 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 20 40 60 80 100

Percent Silt-Clay

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Percent Silt-Clay Content

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 20 40 60 80 100

Percent Silt-Clay

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-9. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. percent siltclay of sediments.

Figure 3.1-10. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. percent

silt-clay of sediments.
51

Sediment Total Organic Carbon

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Percent 

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Total Organic Carbon

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Percent 

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-11. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. percent

total organic carbon of sediments.

Figure 3.1-12. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. percent

total organic carbon of sediments.
52

Mean Chlorophyll a Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 2 4 6 8 10

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Mean Chlorophyll a Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 2 4 6 8 10

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-13. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean concentration of chlorophyll a.

Figure 3.1-14. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column concentration of chlorophyll a.
53

Mean Nitrate Nitrogen Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 50 100 150 200 250

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Mean Nitrate Nitrogen Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 50 100 150 200 250

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-15. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean nitrate concentration.

Figure 3.1-16. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean nitrate concentration.
54

Mean Nitrite Nitrogen Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

012345678

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Mean Nitrite Nitrogen Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

012345678

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-17. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean nitrite concentration.

Figure 3.1-18. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean nitrite concentration.
55

Mean Ammonium Nitrogen Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 20 40 60 80 100

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Mean Ammonium Nitrogen Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 20 40 60 80 100

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-19. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column ammonium concentration.

Figure 3.1-20. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column ammonium concentration.
56

Mean Total Nitrogen Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 50 100 150 200 250 300

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Mean Total Nitrogen Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 50 100 150 200 250 300

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-21. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean total nitrogen (nitrate + nitrite + ammonium) concentration.

Figure 3.1-22. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean total nitrogen (nitrate + nitrite + ammonium) concentration.
57

Mean Orthophosphate Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 100 200 300 400 500

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

 95% Confidence Interval

Mean Orthophosphate Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 100 200 300 400 500

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-23. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean orthophosphate concentration.

Figure 3.1-24. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean orthophosphate concentration.
58

Mean N:P Molar Ratio 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 10 20 30 40 50 60 70

Molar Ratio

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Mean N:P Molar Ratio 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 10 20 30 40 50 60 70

Molar Ratio

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-25. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean ratio of total nitrogen (nitrate + nitrite + ammonium) concentration

to total orthophosphate concentration.

Figure 3.1-26. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean ratio of total nitrogen (nitrate + nitrite + ammonium) concentration

to total orthophosphate concentration.
59

Water Column Dissolved Silicate Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 2000 4000 6000 8000 10000 12000 14000 16000

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Mean Dissolved Silicate Concentration 

Oahu Urbanized Estuaries 

0

20

40

60

80

100

0 2000 4000 6000 8000 10000 12000 14000 16000

Concentration (μg/L)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-27. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column mean silicate concentration.

Figure 3.1-28. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column mean silicate concentration.
60

Bottom Turbidity

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

NTU

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Bottom Turbidity

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

NTU

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-29. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. bottom

water turbidity.

Figure 3.1-30. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. bottom

water turbidity.
61

Surface Turbidity

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 200 400 600 800 1000 1200

NTU

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Surface Turbidity

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 200 400 600 800 1000 1200

NTU

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-31. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. surface

water turbidity.

Figure 3.1-32. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. surface

water turbidity.
62

Secchi Depth

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 2 4 6 8 10 m

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Secchi Depth

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 2 4 6 8 10

m

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-33. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. water

column Secchi depth.

Figure 3.1-34. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. water

column Secchi depth.
63

Δσt

Hawaii Estuaries and Bays

0

20

40

60

80

100

-5 0 5 10 15 20 25

(σt bottom-σt surface)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Δσt

Oahu Urbanized Estuaries

0

20

40

60

80

100

-5 0 5 10 15 20 25

(σt bottom-σt surface)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.1-35. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. )Ft

stratification index.

Figure 3.1-36. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. )Ft

stratification index.
64

3.2 Exposure Indicators

3.2.1 Dissolved Oxygen

Dissolved oxygen (DO) concentrations in the bottom water for the Hawaii estuaries and 

bays ranged from 4.4 mg/L to 8.4 mg/L, across the 50 stations where dissolved oxygen

concentrations were measured. Approximately 7% of estuarine area had a bottom

water DO concentration # 5 mg/L (Fig. 3.2 -1). The range of dissolved oxygen (DO)

concentrations in the surface waters of Hawaii estuaries and bays was very similar to

that for bottom waters (4.6 mg/L to 8.5 mg/L; Fig. 3.2 -3). Only approximately 3.2 % of

the area of Hawaii estuaries and bays had surface DO concentrations # 5 mg/L. 

Dissolved oxygen (DO) concentrations in both the surface and bottom water for the

Oahu urbanized estuaries had a range from 4.2 mg/L to 8.8 mg/L, across the 29

stations where dissolved oxygen concentrations were measured. Approximately 92

percent of the area of Oahu urbanized estuaries had surface and bottom water DO

concentrations > 5 mg/L (Fig. 3.2 -2, Fig. 3.2 -4).
65

Bottom Dissolved Oxygen 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 2 4 6 8 10

Concentration (mg/L)

Cumulative Percent 

Area

Cumulative Percent

95% Confidence Interval

Bottom Dissolved Oxygen 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 2 4 6 8 10

Concentration (mg/L)

Cumulative Percent 

Area

Cumulative Percent

95% Confidence Interval

Figure 3.2 -1. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. dissolved

oxygen of bottom waters.

Figure 3.2 -2. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. dissolved

oxygen of bottom waters.
66

Surface Dissolved Oxygen 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 2 4 6 8 10

Concentration (mg/L)

Cumulative Percent 

Area

Cumulative Percent

95% Confidence Interval

Surface Dissolved Oxygen 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 2 4 6 8 10

Concentration (mg/L)

Cumulative Percent 

Area

Cumulative Percent

95% Confidence Interval

Figure 3.2 -3. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. dissolved

oxygen of surface waters.

Figure 3.2 -4. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. dissolved

oxygen of surface waters.
67

3.2.2 Sediment Contaminants

3.2.2.1 Sediment Metals

Concentrations of sediment metals were measured at 45 stations in the Hawaii

estuaries and bays and at 28 stations in the Oahu urbanized estuaries. The mean

concentration of each metal was calculated with the non-detects (i.e., less than the

MDL) set to 0 (see Table 2.6 for the MDL’s). Field replicates and laboratory replicates

were averaged at stations where replicates were analyzed. For comparative purposes,

mean concentrations of metals were also calculated using the subset of samples in

which the metals were detected (Table 3.2 -1, 3.2-2). 

Arsenic

Arsenic was detected at 41 of the 45 Hawaii estuaries and bays stations. Arsenic

averaged 11.1 :g/g at these stations with a maximum concentration of 50.5 :g/g in

Pohakumanu Bay (Table 3.2-1). Fifty percent of the area of the Hawaii estuaries and

bays had an arsenic concentration less than 6.7 :g/g and 90% of the area had

concentrations less than 25.8 :g/g (Figure 3.2-5). Arsenic was also detected at 27 of

the 28 Oahu urbanized estuary stations. Arsenic averaged 12.1 :g/g at these stations

with a maximum concentration of 27.8 :g/g in Keehi Lagoon Borrow Pit (Table 3.2-2). 

Fifty percent of the area of the Oahu urbanized estuaries had concentrations of 11.6

:g/g or less while 90% of the area had concentrations less than 21.7 :g/g (Figure 3.2-

6). Arsenic concentrations exceeded the ERL at 23 Hawaii estuaries and bays stations

(43% of area) and at 20 Oahu urbanized estuary stations (71% of area), while no

stations had values exceeding the ERM (Table 3.2-1, 3.2-2).

Cadmium

Cadmium was detected at 6 of the 45 Hawaii estuaries and bays stations. Cadmium

averaged 0.01 :g/g at these stations with a maximum concentration of 0.17 :g/g in the

Paukauila Stream (Table 3.2-1). Approximately 90% of the area of Hawaii estuaries

and bays had cadmium concentrations less than 0.01 :g/g (Figure 3.2-7). Cadmium

was also detected at 20 of the 28 Oahu urbanized estuary stations. Cadmium averaged

0.16 :g/g at these stations with a maximum of 0.52 :g/g in Pearl Harbor (Table 3.2-2). 

Fifty percent of the area of the Oahu urbanized estuaries had cadmium concentrations

less than 0.07 :g/g and 90% of the area had concentrations less than 0.40 :g/g (Figure

3.2-8). Cadmium concentrations did not exceed the ERL in any of the Hawaii estuaries

and bays or in the Oahu urbanized estuaries (Tables 3.2-1, 3.2-2).

Chromium

Chromium was detected at all of the 45 Hawaii estuaries and bays stations. Chromium

averaged 102.6 :g/g in these stations with a maximum concentration of 689 :g/g in the

Paukauila Stream (Table 3.2-1). Fifty percent of the area of the Hawaii estuaries and

bays had concentrations less than 18.4 :g/g and 90% of the area had concentrations

less than 186 :g/g (Figure 3.2-9). Chromium was detected at 27 of the 28 Oahu
68

urbanized estuary stations. Chromium averaged 175.6 :g/g in the Oahu urbanized

estuaries (Table 3.2-2) with a maximum concentration of 336 :g/g in Ala Wai Canal.

Fifty percent of the area of the Oahu urbanized estuaries had chromium concentrations

less than 166 :g/g and 90% had concentrations less than 288 :g/g (Figure 3.2-10). 

Chromium concentrations exceeded the ERL at 17 of the Hawaii estuaries and bays

stations (27% of area), while one station in the Paukauila Stream (<1% of area)

exceeded the ERM (Table 3.2-1). Chromium concentrations exceeded the ERL at 23

Oahu urbanized estuary stations (79% of area), with no stations exceeding the ERM

(Table 3.2-2). 

Copper

Copper was detected at 29 of the 45 Hawaii estuaries and bays stations. Copper

averaged 23.3 :g/g in these stations with a maximum concentration of 201 :g/g in the

Moanalua Stream (Table 3.2-1). Fifty percent of the area of the Hawaii estuaries and

bays had concentrations less than 6.5 :g/g while 90% of the area had concentrations

less than 48 :g/g (Figure 3.2-11). Copper was also detected at 27 of the 28 Oahu

urbanized stations. Copper averaged 129 :g/g in the Oahu urbanized estuary stations

with a maximum concentration of 405 :g/g in the Ala Wai Harbor (Table 3.2-2). Fifty

percent of the area of the Oahu urbanized estuaries had concentrations less than 121

:g/g and 90% of the area had concentrations less than 208 :g/g (Figure 3.2-12). 

Copper concentrations exceeded the ERL at 9 Hawaii estuaries and bays stations (14%

of area), with no stations exceeding the ERM (Table 3.2-1). Copper concentrations

exceeded the ERL at 24 Oahu urbanized estuary stations (83% of area), with one

station in the Ala Wai Harbor and one station in Pearl Harbor exceeding the ERM (4%

of area; Table 3.2-2). 

Lead

Lead was detected at 28 of the 45 Hawaii estuaries and bays stations. Lead averaged

3.6 :g/g in these stations with a maximum concentration of 46.5 :g/g in Moanalua

Stream (Table 3.2-1). Fifty percent of the area of the Hawaii estuaries and bays had

concentrations less than 1.0 :g/g and 90% of the area had concentrations less than 7.0

:g/g (Figure 3.2-13). Lead was also detected at 26 of the 28 Oahu urbanized estuary

stations. Lead averaged 42.7 :g/g in the Oahu urbanized estuary stations with a

maximum concentration of 216 :g/g in the Ala Wai Harbor (Table 3.2-2). Fifty percent

of the area of the Oahu urbanized estuaries had concentrations less than 33.9 :g/g and

90% of the area had concentrations less than 78.8 :g/g (Figure 3.2-14). Lead

concentrations did not exceed the ERL or ERM at any of the Hawaii estuaries and bays

stations (Table 3.2-1). In comparison, lead exceeded the ERL concentration at 7 of the

Oahu urbanized estuary stations (20% of area, Table 3.2-2), though no stations

exceeded the ERM.

Mercury

Mercury was detected at 15 of the 45 Hawaii estuaries and bays stations. Mercury

averaged 0.13 :g/g in the Hawaii estuaries and bays with a maximum concentration of

5.23 :g/g in the Moanalua Stream (Table 3.2-1). No other station in the Hawaii
69

estuaries and bays had a concentration >0.12 :g/g. Seventy-two percent of the area of

the Hawaii estuaries and bays had undetectable concentrations of mercury while 90%

of the area had concentrations less than 0.03 :g/g (Figure 3.2-15). Mercury was

detected at 26 of the 28 Oahu urbanized estuary stations. Mercury averaged 0.29 :g/g

in the Oahu urbanized estuaries with a maximum concentration of 1.24 :g/g in the

Kewalo Basin (Table 3.2-2). Fifty percent of the area of the Oahu urbanized estuaries

had concentrations less than 0.24 :g/g and 90% of the area had concentrations less

than 0.51 :g/g (Figure 3.2-16). The Moanalua Stream site was the only station which

exceeded the ERL or ERM in the Hawaii estuaries and bays stations (<1% of area)

(Table 3.2-1). Mercury concentrations exceeded the ERL at 21 of the Oahu urbanized

estuary stations (72% of area), while 2 stations (4% of area) had values exceeding the

ERM (Table 3.2-2). 

Nickel

Nickel was detected at 41 of the 45 Hawaii estuaries and bays stations. Nickel

averaged 76.5 :g/g in these stations with a maximum concentration of 487 :g/g in

Nuupia Pond (Table 3.2-1). Fifty percent of the area of the Hawaii estuaries and bays

had concentrations less than 8.6 :g/g and 90% of the area had concentrations less than

152 :g/g (Figure 3.2-17). Nickel was detected at all 28 Oahu urbanized estuary

stations. Nickel averaged 115.9 :g/g in the Oahu urbanized estuaries with maximum

concentration of 252 ug/g at two stations in Pearl Harbor (Table 3.2-2). Fifty percent of

the area of the Oahu urbanized estuaries had concentrations less than 92 :g/g and

90% of the area had concentrations less than 211 :g/g (Figure 3.2-18).

Nickel concentrations exceeded the ERL at 24 Hawaii estuaries and bays stations (40%

of area), while 18 stations (32% of area) had values exceeding the ERM (Table 3.2-1). 

Nickel concentrations exceeded the ERL at 25 Oahu urbanized estuary stations (84% of

area), while 21 stations (68% of area) had values exceeding the ERM (Table 3.2-2). 

Nickel concentrations in relation to the published ERM values should be interpreted

cautiously since the ERM value has a low reliability (Long et al., 1995). Because of its

unreliability, nickel was excluded from a recent evaluation of sediment quality in

southern Puget Sound (Long et al., 2000). Additionally, a study of metal concentrations

in cores on the West Coast determined an historical background concentration of nickel

in the range of 35 - 70 ppm (Lauenstein et al., 2000), which brackets the value of the

ERM (51.6 ppm). 

Selenium

Selenium was detected at 23 of the 45 Hawaii estuaries and bays stations. Selenium

averaged 0.38 :g/g in the Hawaii estuaries and bays stations with a maximum

concentration of 2.3 :g/g in the Kahului Harbor (Table 3.2-1). Fifty-eight percent of the

area of the Hawaii estuaries and bays had undetectable concentrations of selenium

concentrations and 90% of the area had concentrations less than 1.1 :g/g (Figure 3.2-

19). Selenium was detected in 19 of the 28 Oahu urbanized estuary stations. Selenium

averaged 1.03 :g/g in the Oahu urbanized estuary stations with a maximum

concentration of 3.9 :g/g in Pearl Harbor (Table 3.2-2). Fifty percent of the area of the
70

Oahu urbanized estuaries had concentrations less than 0.6 :g/g and 90% of the area

had concentrations less than 2.5 :g/g (Figure 3.2-20). Selenium concentrations

exceeded the ERL at one of the Hawaii estuaries and bays stations (1% of area), with

no stations exceeding the ERM (Table 3.2-1). Selenium concentrations exceeded the

ERL at 7 Oahu urbanized estuary stations (23% of area), with no stations exceeding the

ERM (Table 3.2-2). 

Silver

Silver was detected at 27 of the 45 Hawaii estuaries and bays stations. Silver averaged

0.11 :g/g in these stations with a maximum concentration of 0.77 :g/g in Kaunakakai

Harbor (Table 3.2-1). Fifty percent of the area of the Hawaii estuaries and bays had

silver concentrations less than 0.01 :g/g and 90% of the area had concentrations less

than 0.23 :g/g (Figure 3.2-21). Silver was detected at all 28 Oahu urbanized estuary

stations. Silver averaged 0.66 :g/g in the Oahu urbanized estuaries with a maximum

concentration of 1.93 :g/g in Pearl Harbor (Table 3.2-2). Fifty percent of the area of the

Oahu urbanized estuaries had silver concentrations less than 0.58 :g/g and 90% of the

area had concentrations less than 1.06 :g/g (Figure 3.2-22). Silver concentrations did

not exceed the ERL or ERM at any of the Hawaii estuaries and bays station (Tables

3.2-1). Silver exceeded the ERL at 4 Oahu urbanized estuary stations (12% area), with

no stations exceeding the ERM (Table 3.2-2). 

Tin

Tin was detected at 34 of the 45 Hawaii estuaries and bays stations. Tin averaged 1.1

:g/g in these stations with a maximum concentration of 7.1 :g/g in Maunalua Bay

(Table 3.2-1). Fifty percent of the area of the Hawaii estuaries and bays had tin

concentrations less than 0.59 :g/g and 90% had concentrations less than 2.89 :g/g

(Figure 3.2-23). Tin was detected at all 28 Oahu urbanized estuary stations. Tin

averaged 6.0 ug/g in the Oahu urbanized estuaries with a maximum of 14 ug/g in the

Ala Wai Harbor (Table 3.2-2). Fifty percent of the area of the Oahu urbanized estuaries

had tin concentrations less than 5.65 :g/g and 90% of the area had concentrations less

than 11.43 :g/g (Figure 3.2-24). There are no ERL or ERM values for tin.

Zinc

Zinc was detected at 41 of the 45 Hawaii estuaries and bays stations. Zinc averaged

47.7 :g/g in these stations with a maximum concentration of 214 :g/g in the Moanalua

Stream (Table 3.2-1). Fifty percent of the area of the Hawaii estuaries and bays had

zinc concentrations less than 19.3 :g/g and 90% of the area had concentrations less

than 86.7 :g/g (Figure 3.2-25). Zinc was detected at all 28 Oahu urbanized estuary

stations. Zinc averaged 189.2 :g/g in the Oahu urbanized estuaries with a maximum

concentration of 362 :g/g in the Ala Wai Harbor (Table 3.2-2). Fifty percent of the area

of the Oahu urbanized estuaries had zinc concentrations less than 181 :g/g and 90% of

the area had concentrations less than 268 :g/g (Figure 3.2-26). Zinc concentrations

exceeded the ERL at 3 Hawaii estuaries and bays stations (<1% of area), with no

stations exceeding the ERM (Table 3.2-1). Twenty-one of the Oahu urbanized estuary

stations exceeded the ERL (68% of area), with no stations exceeding the ERM for zinc
71

(Table 3.2-2).

Additional Metals

In addition to the 11 metals discussed above, aluminum, antimony, iron, and

manganese were measured in the sediments. The mean concentration and frequency

of detection for each of these metals in the Hawaii estuaries and bays are given in

Table 3.2-1 and the corresponding values for the Oahu urbanized estuaries are given in

Table 3.2-2. Not unexpectedly, aluminum and iron were the two most abundant metals,

with mean concentrations ranging from about 11,000 :g/g to 57,000 :g/g. Antimony

was detected in sediments from only 2 samples from Hawaii estuaries and bays, and in

6 samples from Oahu urbanized estuaries.
72

Table 3.2-1. Summary statistics for sediment metal concentrations (:g/g, dry weight) for the Hawaii es

stations (N=45). The mean and standard deviation (SD) were calculated using all the data, including twhich were set to 0. Field duplicates and laboratory duplicates for a station were averaged. The “meawas calculated using the samples which had detectable concentrations of the compound. ERL and ERLong et al. (1995), with NV = no value. NA = not applicable. 

Metal Overall

Mean

Concentration

Overall

SD

Mean

Concentration

when

Present

Min Max Frequency

of

detection

ERL ERM >ERL

No.

Sites

>ERM

No.

Sites

Aluminum 11260 14310 16890 0 48050 30 NV NV NA NA Antimony 0.024 0.12 0.55 0 0.6 2 NV NV NA NA Arsenic 11.1 10.5 12.2 0 50.5 41 8.2 70.0 23 0 Cadmium 0.01 0.04 0.11 0 0.17 6 1.2 9.6 0 0 Chromium 102.6 140.5 102.6 5.3 689 45 81 370 17 1 Copper 23.3 42.3 36.2 0 201 29 34 270 9 0 Iron 22680 28930 23190 0 96200 44 NV NV NA NA Lead 3.6 7.8 5.9 0 46.5 28 46.7 218 0 0 Manganese 399 466 399 21.3 2438 45 NV NV NA NA Mercury 0.13 0.78 0.39 0 5.23 15 0.15 0.71 1 1 Nickel 76.5 111.5 83.9 0 487 41 20.9* 51.6* 24 18 Selenium 0.38 0.56 0.74 0 2.3 23 2.0 25.0 1 0 Silver 0.11 0.18 0.18 0 0.77 27 1.0 3.7 0 0 Tin 1.1 1.7 1.45 0 7.1 34 NV NV NA NA Zinc 47.7 53.4 52.3 0 214 41 150 410 3 0 

* The ERL and ERM for nickel have low reliability for the West Coast. See text for discussion.
73

Table 3.2 -2. Summary statistics for sediment metal concentrations (:g/g, dry weight) for the Oahu urb

stations (N=28). The mean and the standard deviation (SD) were calculated using all the data, includiwhich were set to 0. The “mean when present” was calculated using the samples which had detectable the compound. ERL and ERM values are from Long et al. (1995), with NV = no value. NA = not applic

Metal Overall

Mean

Concentration

Overall

SD

Mean

Concentration

when

Present

Min Max Frequency

of

detection

ERL ERM >ERL

No.

Sites

>ERM

No.

Sites

Aluminum 47150 35450 52810 0 111000 25 NV NV NA NA Antimony 0.07 0.15 0.34 0 0.5 6 NV NV NA NA Arsenic 12.1 6.76 12.5 0 27.8 27 8.2 70.0 20 0 Cadmium 0.16 0.17 0.22 0 0.52 20 1.2 9.6 0 0 Chromium 175.6 97.8 182.1 0 336 27 81 370 23 0 Copper 128.6 86.4 133.3 0 405 27 34 270 24 2 Iron 56530 34620 56530 570 117000 28 NV NV NA NA Lead 42.7 41.3 46.0 0 216 26 46.7 218 7 0 Manganese 779 533 779 43.8 2648 28 NV NV NA NA Mercury 0.29 0.25 0.31 0 1.24 26 0.15 0.71 21 2 Nickel 115.9 78.7 115.9 1.1 252 28 20.9* 51.6* 25 21 Selenium 1.03 1.16 1.52 0 3.9 19 2.0 25.0 7 0 Silver 0.66 0.43 0.66 0.02 1.93 28 1.0 3.7 4 0 Tin 5.99 3.45 5.99 0.1 14 28 NV NV NA NA Zinc 189.2 79.0 189.2 10.7 362 28 150 410 21 0 

* The ERL and ERM for nickel have low reliability for the West Coast. See text for discussion.
74

Sediment Arsenic Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 10 20 30 40 50 60

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Arsenic Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 10 20 30 40 50 60

Concentration (μg/g)

Cumulative Percent 

Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-5. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of arsenic.

Figure 3.2-6. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of arsenic.
75

Sediment Cadmium Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 0.1 0.2 0.3 0.4 0.5 0.6

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Cadmium Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 0.1 0.2 0.3 0.4 0.5 0.6

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-7. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of cadmium.

Figure 3.2-8. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of cadmium.
76

Sediment Chromium Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 100 200 300 400 500 600 700 800

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Chromium Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 100 200 300 400 500 600 700 800

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-9. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of chromium.

Figure 3.2-10. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of chromium.
77

Sediment Copper Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 50 100 150 200 250 300 350 400 450

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Copper Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 50 100 150 200 250 300 350 400 450

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-11. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of copper.

Figure 3.2-12. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of copper.
78

Sediment Lead Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 50 100 150 200 250

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Lead Concentration 

Oahu Urbanized Estuaries 

0

20

40

60

80

100

0 50 100 150 200 250

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-13. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of lead.

Figure 3.2-14. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of lead.
79

Sediment Total Mercury Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0123456

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Total Mercury Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0123456

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-15. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of mercury.

Figure 3.2-16. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of mercury.
80

Sediment Nickel Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 100 200 300 400 500 600

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Nickel Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 100 200 300 400 500 600

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-17. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of nickel.

Figure 3.2-18. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of nickel.
81

Sediment Selenium Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

012345

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Selenium Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

012345

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-19. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of selenium.

Figure 3.2-20. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of selenium.
82

Sediment Silver Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 0.5 1 1.5 2 2.5

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Silver Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 0.5 1 1.5 2 2.5

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-21. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of silver.

Figure 3.2-22. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of silver.
83

Sediment Tin Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 2 4 6 8 10 12 14 16

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Tin Concentration 

Oahu Urbanized Estuaries 

0

20

40

60

80

100

0 2 4 6 8 10 12 14 16

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-23. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of tin.

Figure 3.2-24. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of tin.
84

Sediment Zinc Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 100 200 300 400

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Zinc Concentration 

Oahu Urbanized Estuaries 

0

20

40

60

80

100

0 100 200 300 400

Concentration (μg/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-25. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of zinc.

Figure 3.2-26. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of zinc.
85

3.2.2.2 Sediment Organics

Sediment Organics

Concentrations of sediment organic pollutants were measured at 42 stations in the

Hawaii estuaries and bays and in 28 stations in the Oahu urbanized estuaries. The

mean concentration of each organic compound was calculated with the non-detects

(i.e., less than the MDL) set to 0 (see Table 2.6 for the MDLs). For comparative

purposes, mean concentrations of the organic compounds were also calculated using

the subset of samples in which the compounds were detected.

Total PAHs

PAHs were detected at 8 of the 42 Hawaii estuary and coastal bay stations. Total PAHs

averaged 15.9 ng/g in the Hawaii estuary and bay stations with a maximum

concentration of 336 ng/g in the Moanalua Stream (Table 3.2-3). Eighty-seven percent

of area of Hawaii estuaries and bays had undetectable concentrations of PAHs and

90% of the area had concentrations less than 13.1 ng/g (Figure 3.2-27). No stations

exceeded the ERLs or ERMs for total PAHs, low molecular weight PAHs, or high

molecular weight PAHs. On the average, 89% of the total PAHs in the Hawaii estuary

and bay stations were composed of high molecular weight compounds. 

PAHs were detected at 26 of the 28 Oahu urbanized estuary stations. Total PAHs

averaged 1016 ng/g in the Oahu urbanized estuary stations with a maximum

concentration of 9292 ng/g in the Honolulu Harbor (Table 3.2-4). Eight percent of the

area of the Oahu urbanized estuaries had undetectable concentrations of PAHs while

50% of the area had concentrations less than 262 ng/g and 90% of the area had

concentrations less than 3457 ng/g (Figure 3.2-28). Two stations exceeded the ERL for

total PAHs, constituting 4% of the area of the Oahu urbanized estuaries. The ERL for

high molecular weight PAHs was exceeded at four stations, constituting 12% of the

area. No stations exceeded the ERL for low molecular weight PAHs. On the average,

96% of the total PAHs were composed of high molecular weight compounds.

Total PCBs

PCBs were detected at 30 of the 42 Hawaii estuary and bay stations. Total PCBs

averaged 0.95 ng/g in the Hawaii estuary and bay stations with a maximum

concentration of 6.8 ng/g in the Moanalua Stream (Table 3.2-3). Thirty-nine percent of

the area of the Hawaii estuaries and bays had undetectable concentrations of PCBs

while 50% of the area had concentrations less than 0.32 ng/g and 90% of the area had

concentrations less than 1.66 ng/g (Figure 3.2-29). The ERL was not exceeded at any

station (Table 3.2-3).

PCBs were detected at 24 of the 28 Oahu urbanized estuary stations. Total PCBs

averaged 7.2 ng/g in the Oahu urbanized estuary stations with a maximum of 47.3 ng/g

in Pearl Harbor (Table 3.2-4). Twelve percent of the area of the Oahu urbanized

estuaries had undetectable levels of PCBs while 50% of the area had concentrations

less than 3.2 ng/g and 90% of the area had concentrations less than 23.9 ng/g (Figure
86

3.2-30). The ERL was exceeded at four stations, representing 12.1 % of the area

(Table 3.2-4). No stations exceeded the ERM.

Total DDT

DDT or one of its metabolites was detected at 32 of the 42 of the Hawaii estuary and 

bay stations. Total DDT averaged 0.79 ng/g in the Hawaii estuaries and bays with a

maximum concentration of 10.2 ng/g in the Paukauila Stream (Table 3.2-3). The

compound 4,4'-DDT was the most frequently detected DDT compound and had the

highest mean concentration in the Hawaii estuaries and bays. Thirty-four percent of the

area of the Hawaii estuaries and bays had undetectable levels of DDT and its

metabolites while 50% of the area had concentrations less than 0.21 ng/g and 90% of

the area had concentrations less than 1.18 ng/g (Figure 3.2-31). The ERL for total DDT

was exceeded at four stations representing 3.9% of the area. The ERL for 4,4'-DDE was

exceeded at one station, representing <0.3% of the area. The ERMs were not

exceeded at any stations.

DDT or one of its metabolites was detected at 19 of the 28 Oahu urbanized estuary

stations. Total DDT averaged 2.74 ng/g in the Oahu urbanized estuary stations with a

maximum concentration of 11.9 ng/g in Pearl Harbor. The compound 4,4'-DDT was the

most frequently detected DDT compound in the Oahu urbanized estuary stations, but

4,4'-DDE had a higher average concentration (Table 3.2-4). Thirty-six percent of the

area of the Oahu urbanized estuaries had undetectable levels of DDT and its

metabolites, while 50% of the area had concentrations less than 0.77 ng/g, and 90% of

the area had concentrations less than 5.07 ng/g (Figure 3.2-32). The ERL for total DDT

was exceeded at 13 stations, representing 36% of the area. The ERL for 4,4'-DDE was

exceeded at 6 stations, representing 12% of the area. The ERMs were not exceeded at

any station.

Additional Pesticides

Besides DDT, an additional 13 pesticides were measured in the sediments in the Hawaii

estuaries and bays (Table 3.2-3) and in the Oahu urbanized estuaries (Table 3.2-4). Of

these, Aldrin, Endosulfan I, Endosulfan Sulfate, Heptachlor, Lindane (gamma-BHC) and

Mirex were never detected at any of the stations. Of the remaining pesticides,

Alpha-chlordane had the highest average concentration in both the Hawaii estuaries

and bays and in the Oahu urbanized estuaries. Alpha-chlordane was detected at 26

stations in the Hawaii estuaries and bays, with 50% of the area having concentrations

less than 0.17 ng/g and 90% of the area having concentrations less than 0.70 ng/g.

(Figure 3.2-33). In the Oahu urbanized estuaries, alpha-chlordane was detected at 20

stations, with 50% of the area having a concentration less than 0.55 ng/g and 90% of

the area having a concentration less than 1.99 ng/g (Figure 3.2-34). Among the 

remaining pesticides, hexachlorobenzene and trans-nonachlor had the next highest

concentrations in the Hawaii estuaries and bays while hexachlorobenzene,

trans-nonachlor, and Endosulfan II had the next highest concentrations in the Oahu

urbanized estuaries. Endrin was detected at one site in Honolulu Harbor. The

concentration at this site exceeded the ERL, representing 4% of the area of the Oahu

urbanized estuaries. Other than for alpha-chlordane, there were an insufficient number

of detects to calculate CDFs for any of these additional pesticides.
87

Table 3.2-3. Summary statistics for sediment organic pollutants (ng/g, dry weight) for the Hawaii estua(N=42). The mean and standard deviation (SD) were calculated using all the data, including the non-dset to 0. The “mean when present” was calculated using the samples which had detectable concentratcompound. ERL and ERM values are from Long et al. (1995), with NV = no value. NA = not applicable

Analyte Overall mean

concentration

ng/g dry wt 

Overall 

SD 

Mean

concentration

 when

present

Min Max Frequency

of

detection

ERL ERM >ERL

No. Sites

>ERM

No. Sites

HMW PAHs 14.14 54.01 84.86 0.00 298 7 1700 9600 00LMW PAHs 1.81 7.57 19.00 0.00 38 4 552 3160 00Total PAHs 15.95 61.45 83.75 0.00 336 8 4022 44792 00Total PCBs 0.95 1.37 1.33 0.00 6.80 30 22.7 180 0 0 2,4'-DDD 0.03 0.22 0.03 0.00 0.03 1 NV NV NA NA 2,4'-DDE 0.00 0.00 0.00 0.00 0.00 0 NV NV NA NA 2,4'-DDT 0.00 0.00 0.00 0.00 0.00 0 NV NV NA NA 4,4'-DDD 0.04 0.26 1.71 0.00 1.71 1 NV NV NA NA 4,4'-DDE 0.15 0.72 2.09 0.00 4.53 3 2.2 27.0 1 0 4,4'-DDT 0.57 0.86 0.74 0.00 3.99 32 NV NV NA NA Total DDT 0.79 1.74 1.04 0.00 10.23 32 1.58 46.1 4 0 Aldrin 0.00 0.00 0.00 0.00 0.00 0 NV NV NA NA Alpha-chlordane 0.31 0.32 0.50 0.00 1.30 26 NV NV NA NA Dieldrin 0.06 0.39 2.50 0.00 2.50 1 0.02 8 1 0 Endosulfan I 0.00 0.00 0.00 0.00 0.00 0 NV NV NA NA Endosulfan II 0.00 0.00 0.00 0.00 0.00 0 NV NV NA NA EndosulfanSulfate

0.00 0.00 0.00 0.00 0.00 0

NV NV NA NA 

Endrin 0.00 0.00 0.00 0.00 0.00 0 0.02 45 0 0 Heptachlor 0.00 0.00 0.00 0.00 0.00 0 NV NV NA NA HeptachlorEpoxide

0.01 0.03 0.16 0.00 0.16 2

NV NV NA NA 

Hexachlorobenzene 0.18 0.42 0.92 0.00 1.93 8 NV NV NA NA Lindane(gamma-BHC)

0.00 0.00 0.00 0.00 0.00 0

NV NV NA NA 

Mirex 0.00 0.00 0.00 0.00 0.00 0 NV NV NA NA Trans-nonachlor 0.12 0.45 0.61 0.00 2.85 8 NV NV NA NA 
88

Table 3.2-4. Summary statistics for sediment organic pollutants (ng/g, dry weight) for the Oahu urbaniz(N=28). The mean and standard deviation (SD) were calculated using all the data, including the non-dset to 0. The “mean when present” was calculated using the samples which had detectable concentratcompound. ERL and ERM values are from Long et al. (1995), with NV = no value. NA = not applicabl

Analyte Overall mean

concentration

ng/g dry wt 

Overall 

SD 

Mean

concentration

 when

present

Min Max Frequency

of

detection

ERL ERM >ERL

No. Sites

>ERM

No. Sites

HMW PAHs 977.98 1916.66 1053.21 0 9112 26 1700 9600 4 0 LMW PAHs 37.71 59.25 55.58 0 196.5 19 552 3160 00Total PAHs 1015.70 1966.94 1093.83 0 9292 26 4022 44792 2 0 Total PCBs 7.17 11.16 8.37 0 47.32 24 22.7 180 4 0 2,4'-DDD 0.09 0.48 0.09 0 0.09 1 NV NV NA NA 2,4'-DDE 0.05 0.20 0.74 0 0.93 2 NV NV NA NA 2,4'-DDT 0.03 0.18 0.03 0 0.03 1 NV NV NA NA 4,4'-DDD 0.16 0.56 1.47 0 2.8 3 NV NV NA NA 4,4'-DDE 1.54 2.85 3.93 0 10.90 11 2.2 27.0 6 0 4,4'-DDT 0.86 0.96 1.51 0 3.66 16 NV NV NA NA Total DDT 2.74 3.42 4.04 0 11.87 19 1.58 46.1 13 0 Aldrin 0.00 0.00 0.00 0 0 0 NV NV NA NA Alpha-chlordane 1.17 1.88 1.64 0 9.5 20 NV NV NA NA Dieldrin 0.44 1.25 2.47 0 5.02 5 0.02 8 5 0 Endosulfan I 0.00 0.00 0.00 0 0 0 NV NV NA NA Endosulfan II 0.05 0.24 0.77 0 1.23 2 NV NV NA NA EndosulfanSulfate

0.00 0.00 0.00 0 0 0

NV NV NA NA 

Endrin 0.02 0.12 0.63 0 0.63 1 0.02 45 1 0 Heptachlor 0.00 0.00 0.00 0 0 0 NV NV NA NA HeptachlorEpoxide

0.02 0.06 0.24 0 0.24 2

NV NV NA NA 

Hexachlorobenzen 0.52 0.88 1.83 0 8 NV NV NA NA Lindane(gamma-BHC)

0.00 0.00 0.00 0 0 0

NV NV NA NA 

Mirex 0.00 0.00 0.00 0 0 0 NV NV NA NA Trans-nonachlor 0.77 1.72 1.65 0 7.7 13 NV NV NA NA 
89

Sediment Total PAHs 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 2000 4000 6000 8000 10000

Concentration (ng/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Total PAHs 

Oahu Urbanized Estauries 

0

20

40

60

80

100

0 2000 4000 6000 8000 10000

Concentration (ng/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-27. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of total PAHs.

Figure 3.2-28. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of total PAHs.
90

Sediment Total PCBs Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 10 20 30 40 50

Concentration (ng/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Total PCBs 

Hawaii Estauaries and Bays

0

20

40

60

80

100

0 10 20 30 40 50

Concentration (ng/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-29. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of total PCBs.

Figure 3.2-30. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of total PCBs.
91

Sediment Total DDT Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 2 4 6 8 10 12 14

Concentration (ng/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Total DDT Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 2 4 6 8 10 12 14

Concentration (ng/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-31. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of total DDT.

Figure 3.2-32. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of total DDT.
92

Sediment Alpha-chlordane Concentration 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 2 4 6 8 10

Concentration (ng/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Sediment Alpha-chlordane Concentration 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 2 4 6 8 10

Concentration (ng/g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-33. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. sediment

concentration of alpha-chlordane.

Figure 3.2-34. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. sediment

concentration of alpha-chlordane.
93

3.2.3 Sediment Toxicity

Sediment for toxicity testing with the amphipod Ampelisca abdita was successfully

collected at 44 of the 50 Hawaii estuaries and bays stations, and 28 of the 30 Oahu

urbanized estuaries stations (see section 2.6). Control conditions for a successful

toxicity test with this species require a mean of 90% survival in the five replicates in

control sediments, with no replicate less than 80%. Mean control survival met the

standard in all cases (90 to 98%), but three control batches had minimum replicate

survival < 80%. Thus both requirements were not formally met in testing sediments

collected from 17 of the 72 stations. Because the overall control survival met the

standard, and it is the mean value for control survival that is used to calculate the

control-corrected survival values, these 17 samples were included in the CDF analyses

that follow.

The control corrected mean survivorship of A. abdita in successful bioassays of

sediments collected at the Hawaii estuaries and bays stations ranged from 73.1% to

105.4%, across the 44 stations that were included in the analysis (Figure 3.2 -35). 

Approximately 10% of the area of the Hawaii estuaries and bays had control corrected

mean survivorship of A. abdita in sediment bioassays < 80%. Lowest survival was in

sediments from Stations 6 (Wahiawa Bay), 13 (Kaneohe Bay) and 49 (Hilo Bay),

although these sediments were not acutely toxic, with control corrected survival values

ranging from 73.1 to 78.3 percent. Approximately 16% of area in the Hawaii estuaries

and bays had control corrected mean survivorship > 100%, indicating slightly (1-5%)

higher survival of amphipods in test sediments than in controls.

The control corrected mean survivorship of A. abdita in successful bioassays of

sediments collected in the Oahu urbanized estuaries was above 90% across all of the

28 stations that were included in the analysis (Figure 3.2-36). Approximately 64 % of

area had control corrected mean survivorship > 100%, with the higher survival in the

range of 1-9%. 
94

Percent Survival of Ampelisca abdita

Hawaii Estuaries and Bays

0

20

40

60

80

100

60 80 100 120

Percent Control Corrected Survival (%)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Percent Survival of Ampelisca abdita

Oahu Urbanized Estuaries

0

20

40

60

80

100

60 80 100 120

Percent Control Corrected Survival (%)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-35. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. percent

control corrected survivorship of Ampelisca abdita.

Figure 3.2-36. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. percent

control corrected survivorship of Ampelisca abdita. Note axis differs from 3.2-35.
95

3.2.4 Tissue Contaminants

Residues of a suite of metals, PCBs, PAHs and pesticides were measured in the whole

bodies of holothurians (Holothuria atra and H. whitmaei) at 11 stations in the Hawaii

estuaries and bays and 2 stations in the Oahu urbanized estuaries (see Table 2-4 for

list of compounds analyzed). Residues were not measured at the other stations

because of the unavailability of holothurians. Because of the limited number of samples

and because it is not clear that the sites with holothurians captured for residue analysis

were distributed randomly the tissue residue data are presented as summary statistics

rather than CDFs to estimate areas.

Holothurian tissue residues of the 12 metals are summarized in Table 3.2-5. As

expected, iron and aluminum, which are abundant in volcanic soils, had the highest

concentration. Aside from those two metals, nickel, averaging 8.59 μg/g (wet weight) in

tissue from the Hawaii estuaries and bays and arsenic, averaging 7.55 μg/g (wet

weight) in tissue samples from the Oahu urbanized estuaries, had the highest tissue

metal concentrations. Total metal concentrations varied widely, with the highest

concentrations at Stations 3 and 30 on Kauai and Maui, and the lowest at stations from

Kaneohe Bay. Mercury, cadmium, and silver were undetected in holothurian tissue

samples from either Hawaii estuaries and bays or Oahu urbanized estuaries.

Holothurian tissue residues of total PCBs, PAHs, total DDT, and other pesticides are

summarized in Table 3.2-6. Total PCBs had the highest residue of organic

contaminants but was found at low levels, averaging 2.91 ng/g in samples from the

Hawaii estuaries and bays and 4.82 ng/g in the Oahu urbanized estuaries. Measured

4,4'-DDT constituted 100% of the total DDT and was detected in 3 of the 11 tissue

samples, with maximum values of 2.90 ng/g. Tissue analysis failed to detect

measurable concentrations of any of the following compounds in samples from either

Hawaii estuaries and bays or the Oahu urbanized estuaries: Aldrin, Dieldrin, Endosulfan

I and II, Endosulfan sulfate, Endrin, Alpha-chlordane, Gamma-chlordane, Transnonachlor, Heptachlor, Heptachlor Epoxide, Lindane, Mirex and Toxaphene. No PAHs

were detected in tissue samples from any of the sites sampled.
96

Table 3.2-5. Holothurian tissue residues of metals (μg/g wet weight) from 11 Hawaii

estuaries and bays sites and 2 Oahu urbanized estuaries sites. Values are the

averages of all samples at a station, with the samples consisting of individuals or

composites of up to 3 individuals. “Frequency of Detects” is the number of stations

where the metal was detected at a level above the minimum detection limit (MDL). “No.

Stations” is the number of stations in which tissue was analyzed. A total of 13 tissue

samples were analyzed at 13 stations in the small estuaries.

Metal Mean

 (μg/g wet)

SD Mean when

Present

Minimum Maximum Frequency

of Detects/

No. Stations

Hawaii estuaries and bays

 Aluminum 965 2080 965 35.9 6990 11/11

 Arsenic 4.47 2.34 4.47 0.92 8.70 11/11

 Cadmium 0.00 0.00 0.00 0.00 0.00 0/11

 Copper 0.97 1.19 0.97 0.16 3.70 11/11

 Iron 1580 3150 1580 56.4 10300 11/11

 Lead 0.35 0.49 0.35 0.08 1.80 11/11

 Mercury 0.00 0.00 0.00 0.00 0.00 0/11

 Nickel 8.59 13.4 8.59 0.21 40.5 11/11

 Selenium 1.01 0.51 1.01 0.40 2.10 11/11

 Silver 0.00 0.00 0.00 0.00 0.00 0/11

 Tin 1.66 0.19 1.66 1.20 1.80 11/11

 Zinc 4.21 5.00 4.21 1.40 18.4 11/11

Oahu urbanized estuaries

 Aluminum 74.5 28.1 74.5 54.6 94.4 2/2

 Arsenic 7.55 0.07 7.55 7.50 7.60 2/2

 Cadmium 0.00 0.00 0.00 0.00 0.00 0/2

 Copper 0.57 0.37 0.57 0.31 0.83 2/2

 Iron 98.4 1.34 98.4 97.5 99.4 2/2

 Lead 0.30 0.13 0.30 0.20 0.39 2/2

 Mercury 0.00 0.00 0.00 0.00 0.00 0/2

 Nickel 0.13 0.10 0.13 0.05 0.20 2/2

 Selenium 2.05 1.49 2.05 0.99 3.10 2/2

 Silver 0.00 0.00 0.00 0.00 0.00 0/2

 Tin 1.85 0.07 1.85 1.80 1.90 2/2

 Zinc 4.70 0.28 4.70 4.50 4.90 2/2
97

Table 3.2-6. Holothurian tissue residues of total PCBs, PAHs, total DDT, and

additional pesticides (ng/g wet weight) in samples from 11 Hawaii estuaries and bay

sites and 2 Oahu urbanized estuaries sites. Values are the averages of all samples at a

station, with the samples consisting of individuals or composites of up to 3 individuals. 

“Frequency of Detects” is the number of stations where the organic pollutant was

detected at a level above the minimum detection limit (MDL). “No. Stations” is the

number of stations from which tissue was analyzed. 

Analyte Mean

(ng/g wet)

SD Mean when

Present

Minimum Maximum Frequency

of Detects/

No.

Stations

Hawaii estuaries and bays

 Total PCBs 2.91 2.82 4.57 0.00 8.10 7/11

 Total PAHs 0.00 0.00 0.00 0.00 0.00 0/11

 Total DDT 0.45 1.03 2.50 0.00 2.90 2/11

 Other pesticides 0.00 0.00 0.00 0.00 0.00 0/11

Oahu urbanized estuaries

 Total PCBs 4.82 2.93 4.82 2.74 6.89 2/2

 Total PAHs 0.00 0.00 0.00 0.00 0.00 0/2

 Total DDT 1.20 1.70 2.40 0.00 2.40 1/2

 Other pesticides 0.00 0.00 0.00 0.00 0.00 0/2
98

3.2.5 Bacterial Indicators

The Hawaii Department of Health (HDOH) has a water quality criterion for marine

recreational waters for enterococci of a geometric mean of colony counts of less than 7

colony forming units (cfu) /100 ml of sample water in not less than 5 samples taken over

25-30 days. No single sample shall exceed a count of 100 cfu/ 100 ml (Section 11-54-8,

HDOH, Amendment and Compilation of Chapter 11-54, Hawaii Administrative Rules,

August 31, 2004). Clostridium perfringens is used by HDOH as an indicator of whether

high levels of enterococci potentially originate from human sources (T. Teruya, HDOH). 

A level above 5 cfu/100 ml is considered as potentially indicative of a human related

source (T. Teruya, HDOH). There is no Hawaii marine criterion for fecal coliforms, and

the former freshwater recreational water criterion of 200 cfu/100 ml for 10 samples over

30 days has been replaced by an enterococci criterion. The EMAP sampling took place

on a single sample date for each station, and thus does not formally meet the multisample requirement for the Hawaii enterococci criterion. Additionally, Hawaii has

different criteria for inland waters verus marine waters, and formal interpretation of

bacterial counts would need to consider salinity at the sample site. In the section below,

the cfu values of the criterion are simply used as a relative benchmark for examining the

bacteria data. 

Processing of bacteria samples must commence within 6 hours of collection. Samples

were processed by HDOH branch offices on the various islands to reduce sample

holding times. Table 3.2-7 summarizes the results; overall 227 bacteria samples were

collected from 77 stations (three depths at most stations). Of the 227 samples, 28 did

not meet the 6-hour holding time criterion. Of the 199 samples that did meet the holding

time, nine (or 4.5%) of the total exceeded the state 7 cfu/100 ml criterion for

enterococci. Most of these higher values occurred at stations located at the heads of

harbors and/or in proximity to streams. The highest individual sample count was 100

cfu/100 ml for enterococci in surface water from Honolulu Harbor (HI02-0080), which

would be considered an exceedance of the single sample criterion by HIDOH (T.

Teruya, HDOH). 

For enterococci, surface water sample colony counts ranged from 0.3 to 56 cfu/100 ml

for the Hawaii estuaries and bays (Figure 3.2-37), and from 0.3 to 100 cfu/100 ml for the

Oahu urbanized estuaries (Figure 3.2-38). An estimated 96 % of the area of Hawaii

estuaries and bays and 87 % of the area of Oahu urbanized estuaries had an

enterococci colony count in surface samples of #7 cfu/100 ml (Figures 3.2-37, 38).

Surface water sample colony counts for the indicator organism Clostridium perfringens

for Hawaii estuaries and bays ranged from 0.30 to 11 cfu/100 ml across the 49 stations

where counts were measured (Figure 3.2-39). For the Oahu urbanized estuaries,

surface water sample Clostridium colony counts ranged from 0.30 to 21.0 cfu/100 ml

across the 29 stations where counts were measured (Figure 3.2-40). An estimated 99%

of the area of Hawaii estuaries and bays and 88% of the area of Oahu urbanized

estuaries had a Clostridium colony count in surface samples of #5 cfu/100 ml (Figures

3.2-39, 40).
99

There were a total of five stations, all on Oahu, where Clostridium colony counts were

above 5 cfu/100 ml and enterococci counts were above 7 cfu/100 ml. Locations were in

Paukauila Stream (HI02-0008), and within the urbanized estuaries of Oahu, in Pearl

Harbor, the Ala Wai Canal, and Honolulu Harbor (HI02-0051, HI02-0054,HI02-0071,

HI02-0079).

Surface sample counts of fecal coliform colonies ranged from 0.60 to 22.5 cfu/100 ml for

the Hawaii estuaries and bays (Figure 3.2-41), and from 0.60 to 98.0 cfu/100 ml for the

Oahu urbanized estuaries (Figure 3.2-42). Thus, an estimated 100% of area of both the

Hawaii estuaries and bays and the Oahu urbanized estuaries had a mean fecal coliform

count of #200 cfu/100 ml (Figures 3.2-41, 42).

At several stations in the Hawaii bays and estuaries, surface water sample counts of

enterococci and fecal coliforms, and occasionally Clostridium, were higher than counts

from mid-depth or bottom water samples. For example, the surface water sample was

40 to 60 times greater than mid-depth and bottom water samples from Waimea Bay,

Kauai. In a few cases, such as in Kahului Bay on Maui, mid-depth sample counts

exceeded surface or bottom water counts. In the Oahu urbanized estuaries, Station 71

(Ala Wai Canal) had highest counts in surface waters, Station HI02-0073 (Kewalo

Basin) had higher counts near the bottom, and several stations in Honolulu Harbor and

Pearl Harbor had elevated levels of bacteria throughout the water column. Station

HI02-0051 (Pearl Harbor) with a colony count of 98 cfu/100 ml for fecal coliforms had

data only from the shallow water depth, as the total water depth at this station was 0.01

m.

Table 3.2 -7. Summary of enterococci sampling results, with data presented both for all

samples collected and for samples that met the 6-hour holding time criteria.

Island/Island Group

Parameter Niihau,

Kauai

Oahu Maui Hawaii

All Samples

Total No. Samples 16 137 26 48

Total No. Samples > 7 cfu/100 ml 1 11 1 1

Percent of samples above 7 cfu criterion 6.3 8.0 3.9 2.1

Total No. Samples > 6 hr holding limit 13 4 10 28

Samples Within Holding Limits

Total No. Samples < 6hr Holding Limit 3 133 16 20

Total No. Samples > 7 cfu/100 ml 0 7 1 1

Percent of samples above 7 cfu criterion 0 5.3 6.3 5.0
100

Surface Sample Enterococci Colony Counts

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 20 40 60 80 100 120

Colony Forming Units/100ml

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Surface Sample Enterococci Colony Counts

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 20 40 60 80 100 120

Colony Forming Units/100ml

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-37. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. surface

water sample enterococci colony counts.

Figure 3.2-38. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. surface

water sample enterococci colony counts.
101

Surface Sample Clostridium Colony Counts

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 5 10 15 20 25

Colony Forming Units/100ml

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Surface Sample Clostridium Colony Counts

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 5 10 15 20 25

Colony Forming Units/100ml

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-39. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. surface

water sample Clostridium colony counts.

Figure 3.2-40. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. surface

water sample Clostridium colony counts.
102

Surface Sample Fecal Coliform Counts

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 20 40 60 80 100 120

Colony Forming Units/100ml

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Surface Sample Fecal Coliform Counts

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 20 40 60 80 100 120

Colony Forming Units/100ml

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.2-41. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. surface

water sample fecal coliform counts.

Figure 3.2-42. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. surface

water sample fecal coliform counts.
103

3.3 Biotic Condition Indicators

Soft bottom-dwelling (benthic) invertebrates are important because they are important

food resources for other motile species that may be consumed by humans. In the

Hawaiian Islands, sedimentary materials from terrigenous sources are often most

prevalent in protected water locations such as estuaries, at heads of bays and close to

stream mouths. Many anthropogenic pollutants are known to adhere to particulate and

sedimentary materials that eventually fall to the bottom and are sequestered in the

sediments. The soft-bottom benthos live and feed in these sediments, and thus may

serve as conduits for contaminants moving up through the food web to the human

population.

Sediments were encountered at all but five stations in the 79 sites sampled. Hard

bottom was the only substrate encountered at these five sites. Hard bottom included

basalt boulders and pahoehoe lava substratum (Stations HI02-0004, HI02-0030, HI02-

0032), limestone (Station HI02-0012) or coralline rubble (Station HI02-0037). 

Sediments were present and sampled at all other locations, including all 29 stations

from Oahu urbanized estuaries. 

3.3.1 Infaunal Abundance, Species Richness, and Taxonomic Composition

Benthic species richness on a per sample basis ranged from 4 to 52 species per sample

in the samples from Hawaii estuaries and bays, and from 3 to 43 species per sample

from the Oahu urbanized estuaries. On an areal basis, 50% of the area of the Hawaii

estuaries and bays had a species richness less than 22 species per sample, and 90%

had a richness less than 39 species per sample (Figure 3.3-1). The Oahu urbanized

estuaries had a lower richness, with 50% of the area of these estuaries having fewer

than 8 species per sample and 90% of the area having less than 21 species per sample

(Figure 3.3-2).

The diversity index Hr (log base 2) ranged from 0.32 to 4.68 in the samples from Hawaii

estuaries and bays and ranged from 0.58 to 4.39 in the Oahu urbanized estuaries

(Table 3.3-1). On an areal basis, less than 50% of the area of the Hawaii estuary and

bays had an Hr of 2.79 while 90% of the area had a value of 3.99 or less (Figure 3.3-3). 

In comparison, 50% percent of the area of the Oahu urbanized estuaries had an Hr of

1.95 or less while 90% of the area had an Hr less than 3.00 (Figure 3.3-4). 

Table 3.3 -1 presents a list of the taxa identified in all sediment samples and the number

of stations by island where each taxon occurred. In total, 214 taxa were identified.

Polychaetes comprised 113 taxa (53% of the total) and with crustaceans, (80 taxa, 37%

of the total) were the dominant groups identified in the samples. Some unidentified taxa

(i.e., Nematoda) had high abundance in some samples, and with further taxonomic

treatment could modify the discussion below. 

Benthic infaunal density in samples from Hawaii estuaries and bays ranged from 5 to
104

1927 individuals per 0.0045 m2, and similarly ranged between 8 and 1872 individuals

per 0.0045 m2 in samples from Oahu urbanized estuaries (Table 3.3-1). On an areal

basis, 50% of the area of the Hawaii estuaries and bays had a benthic density less than

270 individuals per 0.0045 m2, and 90% of the area had a density less than 547

individuals per 0.0045 m2

 (Figure 3.3-5). In the Oahu urbanized estuaries, 50% of the

area had benthic densities less than 76 individuals per 0.0045 m2 and 90% of the area

had densities less than 513 individuals per 0.0045 m2 (Figure 3.3-6).

Fully 57 % of the polychaete taxa are classified as nonindigenous in origin, 5 percent as

native, 3 percent as cryptogenic and 35 percent as indeterminate or unclassified. In the

crustaceans, 65 percent of the taxa are considered to be native in origin, 4 percent as

nonindigenous, one percent as cryptogenic and 30 percent as indeterminate. The

percentage of nonindigenous species in the other taxa can not presently be determined

either because the taxa were not identified to a sufficiently low taxonomic level to allow

classification (indeterminate taxa) or because the origins of the species have yet to be

determined (unclassified species) (Table 3.3-1). 

The number of soft-bottom taxa recorded by island is related to sediment characteristics

as well as to the relative sampling effort by island; Niihau received 3% of the sampling

effort (2 stations), Kauai - 6% (5 stations), Oahu - 60% (18 stations in the extensive

survey and 30 stations in the intensive survey), Molokai -1% (1 station), Maui - 11% (9

stations), and Hawaii -19% (15 stations). 

The most abundant taxa collected were the Nematoda (5,801 individuals), followed by

the Oligochaeta (2,762 individuals), polychaetes in the family Spionidae (Streblospio

benedicti - 1,674 individuals, Pygospio muscularis - 1,074 individuals) and

Harpacticoida copepods (1,559 individuals). The polychaete Capitella capitata is

considered an indicator of organic enrichment of sediments (Bailey-Brock et al. 2002). 

This species was abundant on Maui (Station HI02-028), Hawaii (Stations HI02-0047,

HI02-0050) and on Oahu (Stations HI02-0067, HI02-0075). Other polychaete species

that are found in association with fine sediment grain sizes (mud bottoms) include

Armandia intermedia, Cossura coasta and Cossura sp. C as well as Sternaspis sp., all

of which were found in the harbors sampled on Oahu, Maui and Hawaii Islands. The

two Niihau stations (Stations HI02-0001, HI02-0002) yielded four specimens of

Parenterodrilus taeniformis which represents a new record for the Hawaiian polychaete

fauna (Bailey-Brock et al. in prep.). The most abundant crustacean species was the

nonindigenous tanaid, Leptochelia dubia.
105

Table 3.3 -1. Summary of the soft bottom taxa identified from 74 Hawaii EMAP stations where sedimenGiven are the number of stations around a particular island that a taxon was recorded. Data are sepa

sites sampled around 6 islands (the extensive survey) from the 30 intensive survey stations along Oah"Type" refers to the source of each taxon where Nat = native species, NIS = nonindigenous species, Cspecies, I = indeterminate origin, and U = unclassified. 

Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

HYDROZOA I 4 4 ANTHOZOA I 11 4 2 3 2 PLATYHELMINTHES I 12 4 1 2 4 NEMERTEA I 49 3 13 12 7 12 2 NEMATODA I 64 3 15 23 7 14 1 PRIAPULIDA I 7 1 2 2 2 POLYCHAETAAmphiglena mediterranea NIS 2 1 1 Amphiglena sp B I 1 1 Amphinomidae I 11 3 2 2 4 Aonides oxycephala NIS 3 1 2 Aonides sp A I 6 2 1 3 Aphelochaeta marioni NIS 12 5 5 2 Aricidea catherinae NIS 2 1 1 Armandia intermedia NIS 20 2 8 4 5 Augeneriella dubia NIS 1 1 Axiothella quadrimaculata NIS 1 1 Brania rhopalophora NIS 8 3 2 1 2 Capitella capitata Crypto 28 9 12 3 4 Capitellidae spp I 21 6 7 4 4 
Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

106

Caulleriella acicula NIS 2 2 Caulleriella sp A I 3 1 2 Ceratonereis tentaculata NIS 1 1 Chaetopteridae I 8 4 4 Cossura coasta Crypto 3 3 Cossura sp C I 10 2 7 1 Dipolydora normalis NIS 3 2 1 Dodecacaria laddi Crypto 2 1 1 Dorvillea sp D I 1 1 Eunicidae I 1 1 Eumida sanguinea NIS 1 1 Exogone longicornis NIS 5 1 1 1 2 Exogone sp C I 13 8 2 3 Glycera tesselata NIS 5 1 4 Goniada emerita NIS 1 1 Grubeosyllis mediodentata NIS 1 1 Hesionidae sp D I 21 5 5 2 8 1 Hesionura australensis NIS 1 1 Hyboscolex longiseta NIS 1 1 Laonice cirrata NIS 3 3 Linopherus microcephala NIS 11 4 1 1 5 Lumbrineridae sp A I 1 1 Lumbrineris latreilli NIS 1 1 Lumbrineris tetraura NIS 16 1 7 3 2 3 Lysidice ninetta NIS 1 1 
Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

107

Magelona capensis NIS 2 1 1 Magelona sp A I 7 2 1 1 2 Maldanidae sp A I 7 4 1 2 Marphysa conferta NIS 1 1 Megalomma intermedium NIS 3 1 2 Microspio granulata NIS 1 1 Microspio sp A I 2 2 Monticellina cf dorsobranchialis I 4 1 21 Monticellina sp A I 2 1 1 Myriochele oculata NIS 17 3 6 5 3 Naineris sp A I 10 1 4 1 1 2 Neanthes arenaceodentata NIS 5 3 2 Neanthes succinea NIS 2 2 Nematonereis unicornis NIS 12 4 3 1 4 Nereis sp B I 2 2 Notomastus tenuis NIS 5 2 1 1 Ophiodromus angustifrons U 3 11 1 Ophryotrocha adherens NIS 1 1 Ophryotrocha sp C I 1 1 Paraonella sp A I 7 2 2 3 Parenterodrilus taeniformis NIS 2 1 1 Pholoe sp B I 1 1 Phyllochaetopterus sp A I 2 1 1 Phyllochaetopterus verrilli NIS 2 1 1 Phyllodoce madeirensis NIS 4 2 2 
Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

108

Pionosyllis heterocirrata NIS 18 1 4 3 9 1 Pionosyllis spinisetosa NIS 10 4 1 3 1 1 Pionosyllis weismanni NIS 4 4 Pisione sp A I 13 2 1 2 7 1 Plakosyllis quadrioculata NIS 1 1 Polygordius sp A I 2 2 Polynoidae sp E I 1 1 Polyophthalmus pictus NIS 7 7 Prionospio cirrifera NIS 25 4 15 1 5 Prionospio steenstrupi NIS 11 1 6 4 Progoniada sp A Nat 1 1 Protodorvillea biarticulata NIS 8 4 1 2 1 Protodorvillea egena NIS 1 1 Protodrilus sp A I 12 4 1 5 1 Pseudopolydora antennata NIS 1 1 Pseudopolydora corallicola NIS 5 2 3 Pseudopolydora sp C I 3 3 Pseudovermilia occidentalis NIS 1 1 Pygospio muscularis Nat 9 1 4 3 1 Questa caudicirra NIS 13 4 1 2 5 1 Questa sp A Nat 13 2 4 1 2 4 Serpulidae I 1 1 Sabellidae sp I I 22 8 9 4 1 Saccocirrus oahuensis Nat 3 1 2 Saccocirrus waianaensis Nat 5 1 4 
Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

109

Salmacina dysteri Crypto 1 1 Schistomeringos rudolphi NIS 2 1 1 Scolelepis sp B I 7 1 1 3 1 1 Scolelepis victoriensis NIS 2 2 Scyphoproctus djiboutiensis NIS 3 1 1 1 Sigalionidae sp B I 3 2 1 Sigambra tentaculata NIS 3 3 Sphaerodoropsis sp C I 1 1 Sphaerosyllis riseri NIS 4 1 3 Sphaerosyllis sp E I 24 8 7 1 7 1 Spionidae NIS 2 1 1 Spio blakei NIS 20 2 6 1 3 8 Sternaspis sp A I 13 4 8 1 Streblospio benedicti NIS 4 1 3 Syllidae NIS 2 2 Syllides bansei NIS 1 1 Syllides sp B I 1 1 Syllidia armata NIS 2 2 Synelmis albini NIS 1 1 Synelmis sp A I 5 5 Terebellidae sp A I 2 1 1 Trichobranchus glacialis NIS 2 2 Typosyllis aciculata orientalis NIS 7 3 1 1 2 Typosyllis cornuta NIS 14 5 1 1 6 1 Typosyllis variegata Nat 3 2 1 
Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

110

OLIOGOCHAETA I 65 3 17 25 7 11 1 SIPUNCULA I 14 2 3 2 7 ARTHROPODAArachnida I 2 2 Insecta I 6 2 1 2 1 CRUSTACEA IHalacaridae I 4 1 1 1 1 COPEPODA -HARPACTICOIDA I 51 2 10 21 4 12 1 COPEPODA - CALANOIDA I 4 1 3 COPEPODA - CYCLOPOIDA I 3 2 1 BRANCHIOPODA - CLADOCERAPenilia sp. A. I 6 6 OSTRACODA - MYODCOPAMyodocope sp. A. I 15 4 5 2 4 Myodocope sp. B. I 11 1 3 5 1 1 Sarsiella janiceae Nat 3 1 2 OSTRACODA - PODOCOPABairdia hanaumaensis Nat 4 2 2 Bairdia kauaiensis Nat 3 1 1 1 Cytherelloidea cf. monodenticulata Nat 1 1 

LEPTOSTRACA - NEBALACEANebalia sp.A. I 2 1 MYSIDACEA I 4 3 CUMACEA I 8 3 2 1 2 TANIDACEA
Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

111

Anatanais insularis Nat 1 1 Apseudes tropicalis Nat 5 2 2 1 Leptochelia dubia NIS 28 8 9 2 8 Leptochelia sp. A. Crypto. 2 2 ISOPODAApanthura inornata Nat. 3 1 1 1 Caecianiropsis sp. A. Nat. 3 2 1 Cryptoniscus form I 8 1 3 1 3 Dynamenella sp. A. Nat 2 1 1 Hyssuridae sp. A. Nat 2 1 1 Janira algicola Nat 3 1 1 1 Joeropsis hawaiiensis Nat 6 3 2 1 Metacirolana sp. A. Nat 5 3 1 1 Microcharon sp. A. Nat 2 1 1 Munna acarina Nat 8 1 1 2 4 AMPHIPODA - HYPERIIDEA I 1 1 AMPHIPODA - GAMMARIDEAAmphilochidae spp. Nat 13 2 1 1 8 Ampithoe sp. A. Nat 1 1 Aoroides nahili Nat 3 3 Atylus nani Nat 1 1 Bemlos intermedius Nat 1 1 Bemlos macromanus Nat 6 1 4 Corophium insidiosum NIS 5 2 1 1 1 Cymadusa cf. hawaiiensis Nat 1 1 
Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

112

Dulzura laakona Nat 4 4 Dulzura sp. A. Nat 6 3 1 2 Elasmopus piikoi Nat 5 3 1 1 "Elpeddo" sp. A. Nat 5 2 2 Eriopisella sechellensis Nat 11 5 1 1 4 Ericthonius brasiliensis NIS 6 1 1 3 Gammaropsis atlantica Nat 2 1 1 Grandidierella makena Nat 3 1 1 1 Konatopus paao Nat 13 3 2 7 Leucothoe hyhelia Nat 4 2 1 1 Mandibulophoxus hawaiiloa Nat 5 3 2 Melita appendiculata Nat 2 1 1 Melita pahuwai Nat 2 1 1 "Paraphoxus" sp. B. Nat 1 

Pereionotus alaniphilias Nat 1 1 Photis kapapa Nat 1 1 Seba ekepuu Nat 2 1 1 Tethygeneia pacifica Nat 4 2 1 DECAPODA - NATANTIA Alpheus leptochirus Nat 1 1 Alpheus rapax (?) Nat 3 2 1 Leptochela hawaiiensis Nat 1 1 Lucifer chacei Nat 4 4 Nikoides steinii Nat 1 1 Ogyrides sp. A. Nat 1 1 
Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

113

Penaeopsis velatinus Nat 1 1 Pontophilus cf. sculptus Nat 1 1 

Processa hawaiiensis Nat 1 1 Processa cf. macrognatha Nat 2 1 1 

Peneid larva I 1 1 Caridean larva I 9 8 1 DECAPODA - ANOMURAAxius sp. A. I 1 1 Callianassa sp. A. I 6 1 2 3 Calocaris sp. A. I 1 1 DECAPODA - BRACHYURACalappa gallus (?) Nat 2 2 Leucosia (?) sp. A. I 1 1 Lissocarcinus sp. A. I 1 1 Macropthalamus sp. A. I 1 Nucia (?) sp. A. I 2 2 Pilumnus sp. A. I 2 1 1 Portunus orbicularis Nat 1 1 Thalamita auauensis Nat 1 1 Megalops larva I 2 1 1 Zoea larva I 6 1 5 MOLLUSCABivalvia I 26 6 6 6 6 1 Gastropoda I 14 3 2 2 6 PHORONIDA I 8 1 2 3 1 
Taxon Type Number of

stations

Kauai Oahu Oahu

Urbanized

estuaries

Maui Hawaii Niihau Molo

114

ECHNODERMATA IEchinoidea I 6 2 3 1 Holothuroidea I 21 6 8 3 4 Ophiuroidea I 4 1 1 2 CHAETOGNATHA I 12 10 2 HEMICHORDATA I 3 2 1 CHORDATA I 3 1 2 UROCHORDATA I 1 1 OSTEICHTHYES I 5 1 2 1 1 
115

Number of Benthic Species

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 10 20 30 40 50 60

Number of Species

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Number of Benthic Species

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 10 20 30 40 50 60

Number of Species

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.3 -1. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. total

number of species of benthic infauna.

Figure 3.3 -2. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. total

number of species of benthic infauna.
116

Shannon-Weiner Diversity Index 

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

H'

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Shannon-Weiner Diversity Index 

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

H'

Cumulative Percent Area

Cumulative Percent

95% Cinfidence Interval

Figure 3.3 -3. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. H’ diversity

of the benthic infaunal community.

Figure 3.3 -4. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. H’ diversity

of the benthic infaunal community.
117

Abundance of Benthic Organisms

Oahu Urbanized Estuaries

0

20

40

60

80

100

0 500 1000 1500 2000 2500

Number of Organisms

Cumulative Percent Area

Cumulative percent

95% Confidence interval

Abundance of Benthic Organisms

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 500 1000 1500 2000 2500

Number of Organisms

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.3 -5. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. total

abundance of benthic infauna.

Figure 3.3 -6. Percent area (and 95% C.I.) of Oahu urbanized estuaries vs. total

abundance of benthic infauna.
118

3.3.2 Hard Bottom Habitat Composition

Underwater biological sample collections were carried out by SCUBA divers at 38 of the

79 (or 48%) completed survey sites (Table 3.3-2). However, only three of these 38

underwater transects were completed at the 30 stations located in the Oahu urbanized

estuaries. The low number of surveys at the stations in the Oahu urbanized estuaries

precluded the calculation of CDFs for data collected at this group of sites.

At most of the harbor sites, surveys could not be completed due to the presence of poor

visibility and/or fine mud substratum. Among the stations in Hawaii estuaries and bays,

dangerous surf found on some reef crest sites along windward coasts also precluded

diver sampling. Several other stations at low energy, poor visibility sites, usually in

proximity to stream discharges, also could not be sampled. At locations where in-water

diver surveys were not completed, all needed biological sample collections were made

using standard methods (i.e., Van Veen grabs, etc.). Where sample sites occurred in

coral reef settings, all biological sample collections were made using divers.

3.3.2.1 Algal Composition

Macrothalloid algae were recorded as the percent cover of each species present. In

total 54 species of macroalgae were seen in the quadrat surveys. The ten most

abundant algal taxa observed are given in Table 3.3-3. The mean algal coverage was

7.4%. Mean algal percent cover ranged between 0 and 70%, with 90% of the area of

Hawaii estuaries and bays having an algal percent coverage less than approximately

14% (Figure 3.3-3). Among the islands, mean percentage algal coverage was as

follows: Niihau - 4.6%, Kauai - 5.9%, Oahu - 9.7% Maui - 15.0% and Hawaii - 0.9%. 

The lower abundance of macrothalloid algal species around the island of Hawaii is

probably related to the higher abundance of herbivorous invertebrates and fishes

relative to other islands.

Nonindigenous algal species have become a concern in the Hawaiian Islands in recent

years. There are eight species (Acanthophora spicifera, Avrainvillea amadelpha,

Gracilaria salicornia, G. tikvahiae, Hypnea musciformis, Kappahhycus alvarezii, K.

stratium and Halophila decipiens) generally recognized as being prominent nuisance

species; three of these (Acanthophora spicifera, Gracilaria salicornia and Avrainvillea

amadelpha) were encountered in this survey. These three nonindigenous species were

only found at six Oahu sample sites, where they comprised a total of 53% of the algal

cover. Plant abundances of the first two of these species were also among the ten

most abundant algal species. No nonindigenous algae were found at any of the other

survey sites although several are known to commonly occur in the waters around other

islands. 
119

Table 3.3 -2. Summary of biological parameters at all stations where underwater transect measureme

out.

EMAP

Station ID

Island No. Coral

Species

% Coral

Cover

No.

Algal

Species

% Algal

Cover

No. Fish

Species

No. Fish

Individuals

Fish

Biomass

No.

Invertebrate

Species

No.

Invertebrate

Individuals

HI02-0001 Niihau 1 0.2 7 8.7 10 42 4.72 5 30HI02-0002 Niihau 0 0 1 0.4 6 35 11.2 0 0HI02-0003 Kauai 6 21.7 6 5.9 9 57 7.5 3 3HI02-0009 Oahu 1 11 3 13.9 1 2 0.01 2 8HI02-0010 Oahu 6 2 5 3.2 8 19 3.7 2 6HI02-0012 Oahu 4 1.1 12 15.8 4 9 0.8 5 195HI02-0013 Oahu 1 0.3 11 33.3 5 31 5 5 93HI02-0014 Oahu 6 7.1 3 2.3 12 52 12.3 0 0HI02-0017 Oahu 2 23.4 3 4.3 13 77 40 2 4HI02-0021 Oahu 1 0.4 0 0 2 13 0.5 5 31HI02-0022 Oahu 0 0 5 10.3 11 60 7.3 2 2HI02-0023 Oahu 1 5.8 4 11.1 8 61 3.9 2 45HI02-0024 Oahu 0 0 8 9.3 2 4 2.1 2 2HI02-0025 Oahu 4 1.2 0 0 17 68 24.3 6 29HI02-0027 Maui 0 0 0 0 0 0 0 0 0HI02-0028 Maui 7 38.2 7 10.6 12 61 33.1 1 1HI02-0030 Maui 3 1.2 4 30.1 3 5 2.4 3 4HI02-0031 Maui 0 0 0 0 2 20 0.7 1 13HI02-0032 Maui 3 4.2 5 69.9 18 107 9.6 4 6HI02-0033 Maui 6 34.5 1 9.3 10 27 2.8 4 64HI02-0034 Maui 0 0 0 0 1 52 3.8 2 28HI02-0035 Maui 0 0 0 0 0 0 0 0 0HI02-0036 Hawaii 9 59.4 0 0 31 278 186 5 94
EMAP

Station ID

Island No. Coral

Species

% Coral

Cover

No.

Algal

Species

% Algal

Cover

No. Fish

Species

No. Fish

Individuals

Fish

Biomass

No.

Invertebrate

Species

No.

Invertebrate

Individuals

120

HI02-0037 Hawaii 6 7.1 2 0.3 7 67 6.5 4 61HI02-0038 Hawaii 5 99.7 0 0 18 162 71.4 4 106HI02-0039 Hawaii 3 13.2 0 0 8 41 6.4 1 2HI02-0040 Hawaii 6 43.5 1 0.4 20 107 46.7 5 42HI02-0041 Hawaii 0 0 0 0 5 6 6.1 1 1HI02-0042 Hawaii 8 33.8 2 6.2 13 99 26.4 5 526HI02-0043 Hawaii 0 0 0 0 13 74 11.5 5 37HI02-0044 Hawaii 0 0 0 0 0 0 0 0 0HI02-0045 Hawaii 3 4.1 3 1.8 18 168 22.8 3 3HI02-0046 Hawaii 5 4.7 5 2.8 9 46 24.7 2 3HI02-0047 Hawaii 8 7.6 1 0.2 13 126 77.7 0 0HI02-0050 Hawaii 0 0 0 0 1 12 5.9 0 0HI02-0061 Oahu 1 0.5 2 17.3 13 130 58.8 1 23HI02-0069 Oahu 1 1 7 7.2 3 12 3 4 20HI02-0078 Oahu 0 0 4 8 0 0 0 3 3

MEAN 2.82 11.23 2.95 7.44 8.58 56.05 19.20 2.61 39.08
121

Table 3.3-3. The ten most abundant algal taxa observed on the underwater transects. 

Algal abundance represents total number of plants observed, and percent cover

was calculated for stations where the alga occurred. (* = nonindigenous species)

Freq. of

occurrence

Algal Species Type Algal

abundance

Percent

cover

1 Sargassum echinocarpum Phaeophyta 315.0 1.38 

4 Sargassum sp. Phaeophyta 196.5 0.86 

10 Padina sp. Phaeophyta 144.3 0.63 

5 Acanthophora spicifera* Rhodophyta 132.2 0.57 

4 Dictyopteris sp. Phaeophyta 113.5 0.50 

1 Gracilaria salicornia* Rhodophyta 99.7 0.44 

2 Microdictyon sp. Chlorophyta 69.5 0.30 

5 Porolithon sp. Rhodophyta 63.0 0.28 

1 Dictyopteris australis Phaeophyta 57.0 0.25 

1 Galaxaura acuminata Rhodophyta 56.0 0.24 

Table 3.3-4. The ten most abundant coral taxa observed on the underwater transects. 

Freq. of

occurrence

Species Common Name Coral

coverage

Percent of total

coverage

12 Porites compressa Finger coral 946.75 4.15 

19 Porites lobata Lobe coral 738.00 3.24 

14 Montipora capitata Rice coral 399.00 1.75 

7 Montipora patula Sandpaper rice coral 120.25 0.53 

13 Pocillopora meandrina Cauliflower coral 93.75 0.41 

9 Montipora flabellata Blue rice coral 77.50 0.34 

7 Pavona varians Corrugated coral 28.00 0.12 

2 Porites evermanni Evermann's coral 20.25 0.09 

2 Leptastrea purpurea Crust coral 18.00 0.08 

3 Psammocora stellata Stellar coral 10.50 0.05 
122

3.3.2.2 Coral Composition

Corals were found at 26 of 38 (68%) stations surveyed. At sites with corals present, the

number of coral species ranged from 1 to 9 per transect (Table 3.3-4), with a mean of 4

species per transect. Coral coverage at the 26 sites with corals present ranged from

0.2% to 99.7% with a mean of 16.4%. 

By island, mean coral coverage at the sampled stations varied; Niihau had corals

present at one of two sites surveyed and mean cover at those stations was 0.1%. On

Kauai there was one station surveyed for corals and mean coverage along the transect

surveyed was 21.7%. Eleven Oahu stations out of 14 surveyed for corals had corals

present. The mean coverage at the Oahu sites with corals was 4.9% and at all Oahu

sites it was 3.8%. On Maui four out of eight stations had corals present; at those

stations where corals were present mean coverage was 19.5% and considering all eight

Maui stations mean coverage was 9.8%. On the island of Hawaii, corals were present at

9 of 13 stations where the mean coverage was 30.3%. Considering all 13 stations,

mean coral coverage amounted to 21.0%. Coral coverage is largely influenced by the

presence of appropriate hard substratum on which to settle and grow, the degree of

sample site exposure from occasional storm surf, and the proximity of streams. All coral

species seen in this survey are native species. 

3.3.2.3 Macroinvertebrate Composition

Diurnally-exposed motile macroinvertebrates were censused in 25 x 4 m transects. 

Motile macroinvertebrates were found at 31 of the 38 sites censused. A total of 31 taxa

were identified, with a mean number of macroinvertebrate taxa per transect of 2.6. The

ten most abundant macroinvertebrate taxa are given in Table 3.3-5. Six of the ten most

abundant macroinvertebrate taxa were sea urchins. Mean abundance of

macroinvertebrates was 39 individuals per transect. Fully 24 species (or 77% of the

taxa) are native (16 species being echinoderms), one is cryptogenic (the feather duster

worm - Sabellastarte spectabilis) and six are indeterminate. The cryptogenic feather

duster worm was found only at one station within Pearl Harbor. None of the diurnallyexposed macroinvertebrates encountered in this study are rare and the sampling method

is probably only accurate for a few echinoderm and mollusk species because of the

normal cryptic habits of most coral reef invertebrates. Thus the data are of limited value

in assessing the status of marine communities in Hawaii.
123

Table 3.3-5. The ten most abundant macroinvertebrate taxa observed on the underwater

transects. Abundance represents the total number of individuals observed, while mean

abundance is for sites where the species occurred.

Freq. of

occurrence

Macroinvertebrate

species

Common name Abundance Mean per

transect

St.

Dev.

12 Echinometra mathaei Rock-boring urchin 862 71.83 141.47 

10 Tripneustes gratilla Collector urchin 226 22.60 24.38 

2 Heterocentrotus Red pencil urchin 62 31.00 29.00 

5 Alpheidae sp. Snapping shrimp 57 9.67 9.29 

9 Diadema paucispinum Long-spined urchin 42 4.67 5.60 

5 Eucidaris tribuloides Slate-pencil urchin 40 8.00 7.32 

4 Echinometra oblonga Oblong urchin 38 9.50 9.50 

4 Ophiocoma sp. Brittle star 36 9.00 5.70 

1 Sabellastarte spectabilis Feather duster worm 23 23.00 0.00 

10 Holothuria atra Black sea cucumber 19 1.90 1.14 
124

3.3.3 Fish Species Richness, Abundance and Biomass

The visual censusses of fishes were carried out at 38 of the 79 (48%) Hawaiian NCA

stations and fishes were encountered at 34 of the 38 sites. Of the 38 sites with

successful fish visual surveys, only 3 sites were located among Oahu urbanized

estuaries. Therefore, no CDFs were generated from this portion of the study for fish

indicators.

In total, 110 species/taxa were encountered from the 38 sites. The mean number of fish

taxa per transect was 9, mean number of fishes/transect was 56 and mean estimated

biomass was 19 g/m2

 per transect. Within the 110 fish taxonomic groups, there are 9

taxa (Coris spp., Rhinecanthus spp., Forcipiger spp., Synodus spp., Cantherhines spp.

Scarus sp., Calatomus sp., Sargocentron sp. and Goby spp.) incompletely identified. 

Eight of these nine taxa have no known nonindigenous or cryptogenic species in the

Hawaiian fish fauna (Randall 1981, 1987) thus are all considered to be native. One

taxon (Goby spp.) could contain nonindigenous or cryptogenic species thus is classified

as indeterminate. Three species are nonindigenous (blue spotted grouper or

roi,Cephalopholis argus; the blue lined snapper or ta’ape, Lutjanus kasmira; and the

blacktail snapper to’au, Lutjanus fulvus), having been intentionally released in Hawaiian

waters in the mid-1950's to supplement inshore fishery resources (Brock 1960). Table

3.3-6 lists the ten most abundant fish taxa recorded.

Fish species richness on a per sample basis ranged from 0 to 31 species per transect in

the samples from Hawaii estuaries and bays. On an areal basis, approximately 50% of

the area had a species richness less than 8 species per transect, and 90% had a fish

species richness less than 18 species per sample (Figure 3.3-7). 

The fish diversity index Hr (log base 2) ranged from 0 to 3.58 in the samples from

Hawaii estuaries and bays. On an areal basis, less than 50% of the area had an Hr of

2.5, while 90% of the area had a value of 3.18 or less (Figure 3.3-8).

Fish abundance per transect in samples from Hawaii estuaries and bays ranged from 0

to 278 individuals. On an areal basis, 50% of the area had a fish abundance less than

48 individuals per transect, and 90% of the area had an abundance less than 126

individuals (Figure 3.3-9). 

Estimated fish biomass per transect in samples from Hawaii estuaries and bays ranged

from 0 to 18.6 kg per transect. On an areal basis, 50% of the area had a fish biomass

less than 0.6 kg per transect and 90% of the area had a fish biomass less than 4.0 kg

per transect (Figure 3.3-10). 
125

Table 3.3-6. The ten most abundant fish taxa observed on the underwater transects. 

Abundance represents the total number of individuals observed on all transects.

Freq. of

occurrence

Fish Species Common Name Abundance Mean per

transect

St.

Dev.

25 Thalassoma duperrey Saddleback 309 12.36 9.95 

17 Acanthurus nigrofuscus Brown 196 11.53 12.08 

8 Ctenochaetus strigosus Goldring 162 20.25 15.21 

6 Chromis vanderbilti Blackfin chromis 138 23.00 11.34 

8 Goby spp. Goby 136 17.00 15.67 

3 Chromis agilis Agile chromis 90 30.00 18.46 

3 Mulloidichthys Yellowstripe 89 29.67 17.78 

5 Acanthurus Whitebar 87 17.40 29.86 

7 Acanthurus triostegus Convict 78 11.14 14.21 

4 Scarus spp. Parrotfish 66 16.50 7.30 
126

Fish Species Richness

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 5 10 15 20 25 30 35

Number of Species

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Shannon-Weiner Diversity Index

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 0.5 1 1.5 2 2.5 3 3.5 4

H'

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.3 -7. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. total

number of fish species observed on visual transects.

Figure 3.3 -8. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. the H’

diversity index for fishes observed on visual transects.
127

Total Number of Fish

Hawaii Estuaries and Bays

0

20

40

60

80

100

0 50 100 150 200 250 300

Number of Fish

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Fish Biomass

 Hawaii Estuaries and Bays

0

20

40

60

80

100

0 5000 10000 15000 20000

Biomass (g)

Cumulative Percent Area

Cumulative Percent

95% Confidence Interval

Figure 3.3 -9. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. abundance

of fishes observed on visual transects.

Figure 3.3 -10. Percent area (and 95% C.I.) of Hawaii estuaries and bays vs. the

estimated biomass of fishes observed on visual transects.
128

4.0 References

American Society for Testing and Materials (ASTM). 1991. Guide for conducting 10-

day static sediment toxicity tests with marine and estuarine amphipods. ASTM

Standard Methods Volume 11.04, Method Number E-1367-90. ASTM,

Philadelphia, PA.

Bailey-Brock, J. H., B. Paavo, B. M. Barret and J. Dreyer. 2002. Polychaetes

associated with a tropical ocean outfall: synthesis of a biomonitoring program off

O’hau, Hawai’i. Pacific Science 56:459-479.

Bailey-Brock, J. H., R. E. Brock and M. McGurr. (In prep.). Protodrilidae of Hawaii and

Niihau in the Hawaiian Islands. Ms. 6p+2 figs.

Bisson, J.W, and V.J. Cabelli. 1979. Membrane filter enumeration method for

Clostridium perfringens. Applied Environmental Microbiology. 37:55-66.

Brock, R. E. 1982. A critique on the visual census method for assessing coral reef

populations. Bulletin of Marine Science 32:269-276.

Brock, R. E. 1998. Community structure and macrobenthos at selected sites fronting

Sand Island, O’ahu, Hawai’i, in relation to the Sand Island ocean outfall, year 9 -

1998. Project Report PR-99-07. Water Resources Research Center, University

of Hawaii, Honolulu. viii+41p.

Brock, R. E. 1999. Community structure and macrobenthos at selected shallow-water

sites in relation to the Barbers Point ocean outfall, 1999. Project Report PR-99-

13. Water Resources Research Center, University of Hawaii, Honolulu. viii+51p.

Brock, R. E. and J. H. Brock. 1977. A method of quantitatively assessing the infaunal

community residing in coral rock. Limnology and Oceanography 22:948-951.

Brock, R. E. and J. E. Norris. 1989. An analysis of the efficacy of artificial reef designs

in tropical waters. Bulletin of Marine Science 44:934-941.

Brock, V. E. 1954. A preliminary report on a method of estimating reef fish populations. 

Journal of Wildlife Management. 18:297-308.

Brock, V. E. 1960. The introduction of aquatic animals into Hawaiian waters. Int.

Revue ges. Hydrobiologia 45:463-480.

Bourgeois, P. E., V. J. Sclafani, J. K. Summers, S. C. Robb and B. A. Vairin. 1998.

Think before you sample. GEOWorld. Vol. 11: No 12.
129

Carlton, J. T. 1996. Biological invasions and cryptogenic species. Ecology 77:1653-

1654.

Carlton, J. T. and J. B. Geller. 1993. Ecological roulette: the global transport of

nonindigenous marine organisms. Science 261:78-82.

Cohen, A. and , J. T. Carlton. 1995. Nonindigenous aquatic species in a United States

estuary: A case study of the biological invasions of the San Francisco Bay and

Delta. Report for the National Sea Grant College Program, DT and the U.S. Fish

and Wildlife Service, Washington, D.C. Report No. PB 96-166525.

Cohen, A. and J. Carlton. 1998. Accelerating invasion rate in a highly invaded estuary.

Science 279:555-558.

Cooper, L. 2000. West EMAP Revised Information Management Plan for 2000. Draft.

14 p. plus Appendices A-D.

Cooper, S. R. and G. S. Brush. 1991. Long-term history of Chesapeake Bay anoxia. 

Science 254:993-996.

Copping, A. and B. C. Bryant. 1993. Pacific Northwest Regional Marine Research

Program, Vol. 1. Research Plan, 1992-1996. Office of Marine Environmental and

Resource Programs, University of Washington, Seattle.

Culliton, T. J., M. A. Warren, T. R. Goodspeed, D. G. Remeer, C. M. Blackwell and 

J. J. McDonough, III. 1990. 50 Years of Population Change along the Nation’s

Coasts, 1960-2010. NOAA, Office of Oceanography and Marine Assessment,

National Ocean Service, Coastal Trends Series, Rockville, MD. pp 41.

Diaz-Ramos, S., D. L. Stevens, Jr. and A. R. Olsen. 1996. EMAP Statistics Methods

Manual. EPA/620/R-96/002. Corvallis, OR: U.S. Environmental Protection

Agency, Office of Research and Development, National Health and

Environmental Effects Research Laboratory. 

Durning, A. T. 1996. The six floods. WorldWatch November/December 1996. pp. 28-

36.

Englund, R. A., D. J. Preston, R. Wolff, S. L. Coles, L. G. Eldredge, K. Arakai, eds.

2000. Biodiversity of Freshwater and Estuarine Communities in Lower Pearl

Harbor, Oahu, Hawaii with Observations on Introduced Species. Final Report

prepared for the U.S. Navy. Department of Defense Legacy Project Number 106.

Bishop Museum Technical Report No. 16. Honolulu. pp. 167.

Evans, E.C. (Editor). 1974. Pearl Harbor biological survey - final report. Report No.

NUC-TN-1128, Naval Undersea Center, Hawaii Laboratory. 
130

Holland, A. F. and A. T. Shaughnessey. 1986. Separation of long term variation in

benthic organisms into major components. In: Oceans 86 Conference Record.

Vol. 3. Monitoring strategies symposium. Institute of Electrical and Electronic

Engineers, Piscataway, NJ. pp. 1056-1061.

Howarth, R. W., J. R. Fruch and D. Sherman. 1991. Inputs of sediment and carbon to

an estuarine ecosystem: influence of land use. Ecological Applications 1:27-39.

Hyland, J. L., L. Balthis, C. T. Hackney, G. McRae, A. H. Ringwood, T. R. Snoots, R. F.

Van Dolah and T. L. Wade. 1998. Environmental quality of estuaries of the

Carolinian Province: 1995. Annual statistical summary for the 1995 EMAPEstuaries Demonstration Project in the Carolinian Province. NOAA Technical

Memorandum NOS ORCA 123 NOAA/NOS, Office of Ocean Resources

Conservation and Assessment, Silver Spring, MD. 143 p.

Hyland, J. L., T. J. Herrlinger, T. R. Snoots, A. H. Ring-wood, R.F. Van Dolah, C. T.

Hackney, G. A. Nelson, J. S. Rosen and S. A. Kokkinakis. 1996. Environmental

Quality of Estuaries of the Carolinian Province: 1994. Annual Statistical Summary

for the 1994 EMAP- Estuaries Demonstration Project in the Carolinian Province.

NOAA Technical Memorandum NOS ORCA 97. NOAA/NOS, Office of Ocean

Resources Conservation and Assessment, Silver Spring, MD. 102 p.

Lauenstein, G. G. and A. Y. Cantillo (eds.). 1993. Sampling and analytical methods of

the National Status and Trends Program National Benthic Surveillance and

Mussel Watch Projects 1984-1992: Comprehensive descriptions of trace organic

analytical methods, Volume IV NOAA Technical Memorandum NOS ORCA 71,

Silver Spring, MD. 182 pp.

Lauenstein, G. G., Crecelius, E. A. and Cantillo, A. Y. 2000. Baseline metal

concentrations of the U.S. West Coast and their use in evaluating sediment

contamination. Presented at 21st Ann. Soc. Environ. Toxicology and Chemistry

meeting, November 12 - 15, 2000, Nashville Tennessee.

Lee, H. II, B. Thompson and S. Lowe. 2003. Spatial patterns and associations of

nonindigenous benthos in the San Francisco estuary. Biological Invasions 5:85-

102.

Leppäkoski, E. 1979. The use of zoobenthos in evaluating effects of pollution in

brackish-water environments. In: The use of ecological variables in

environmental monitoring. The National Swedish Environment Protection Board,

Report PM 1151. pp. 151-157.

Long, E. R., D. D. MacDonald, S. L. Smith and F. D. Callander. 1995. Incidence of

adverse biological effects within ranges of chemical concentrations in marine and

estuarine sediments. Environmental Management 19:81-97.
131

Long, E. R.,, J. Hameedi, A. Robertson, M. Dutch, S. Aasen. K. Welch, S. Magoon, R.

Carr, T. Johnson, J. Biedenbach, K. Scott, C. Mueller and J. Anderson. 2000.

Sediment Quality in Puget Sound. Year 2 - Central Puget Sound. National

Oceanic and Atmospheric Administration, National Ocean Service, Silver Spring,

MD. NOS NCCOS CCMA Technical Memo No. 147 , and Washington State

Department of Ecology, Olympia, WA, Publication No. 00-03-055. pp. 353.

Macauley, J. M., J. K. Summers, P. T. Heitmuller, V. D. Engle, G. T. Brooks, M.

Babikow and A. M. Adams. 1994. Annual Statistical Summary: EMAP - Estuaries

Louisiana Province - 1992. U.S. EPA Office of Research and Development,

Environmental Research Laboratory, Gulf Breeze, FL. EPA/620/R-94/002. 82 p.

plus Appendix A.

Macauley, J. M., J. K. Summers, V. D. Engle, P. T. Heitmuller and A. M. Adams. 1995.

Annual Statistical Summary: EMAP - Estuaries Louisiana Province -1993. U.S.

EPA Office of Research and Development, Environmental Research Laboratory,

Gulf Breeze, FL. EPA/620/R-96/003. 95 p.

Nelson, W. G. 1986. Benthic infaunal sampling in vicinity of the Sand Island ocean

outfall, O’ahu, Hawai’i. Spec. Rept. 6:20:86, Water Resources Research Center,

University of Hawaii, Honolulu. 117p.

Oregon Coastal EMAP Proposal. 1999. Monitoring the US West Coast: An initial

assessment of Oregon’s estuaries and the Pacific Ocean. A proposal to the

United States Environmental Protection Agency EMAP Program. Submitted by:

Oregon Department of Environmental Quality, Laboratory Division, 1712 SW

Eleventh Avenue, Portland, Oregon 97201. Unpublished, 31p.

Preskitt, L. B., C. M. Smith, I. A. Abbott, R. C. DeFelice, L. G. Eldredge and J. T.

Carlton. 2001. A Guidebook of Introduced Marine Species in Hawai'i. A

Workshop at the University of Hawaii, May 18, 2001. Sponsored by grants from

the Packard Foundation and the US Fish & Wildlife Service and to the University

of Hawai'i and Bishop Museum. pages A-ii+A60, B-iv+B-60.

Randall, J. E. 1981. New records of fishes from the Hawaiian Islands. Pacific Science

34:211-232.

Randall, J. E. 1987. Introductions of marine fishes to the Hawaiian Islands. Bulletin of

Marine Science 41:490-502.

Reish, D. J. 1986. Benthic invertebrates as indicators of marine pollution: 35 years of

study. In: Oceans 86 Conference Record. Vol. 3. Monitoring strategies

symposium. Institute of Electrical and Electronic Engineers, Piscataway, NJ pp.

885-888.
132

Ricker, W. E. 1975. Computation and interpretation of biological statistics of fish

populations. Bull. Fish. Res. Bd. Canada, 191. 382p.

Sanders, H., R. Hessler and G. Hampson. 1965. An introduction to the study of deepbenthic faunal assemblages along the Gay Head-Bermuda transect. Deep Sea

Res. 12:845-867.

Simenstad, C. A., J. A. Estes and K. W. Kenyon. 1978. Aleuts, sea otters, and

alternate stable state communities. Science 200:403-41.

Standard Methods for the Examination of Water and Wastewater. 20th edition. 1998.

American Public Health Association, Washington, DC.

Stevens, D. L. Jr. 1997. Variable density grid-based sampling designs for continuous

spatial populations. Environmetrics 8:167-195.

Stevens, D. L., Jr. and A. R. Olsen. 1999. Spatially restricted surveys over time for

aquatic resources. Journal of Agricultural, Biological and Environmental

Statistics: 4:415-428.

Strobel, C. J., H. W. Buffum, S. J. Benyi, E. A. Petrocelli, D. R. Reifsteck and D. J.

Keith. 1995. Statistical summary: EMAP - Estuaries Virginian Province - 1990 to

1993. U.S. EPA National Health and Environmental Effects Research Laboratory,

Atlantic Ecology Division, Narragansett, R.I. EPA/620/R-94/026. 72 p. plus

Appendices A–C.

Strobel, C.J., S. J. Benyi, D. J. Keith, H. W. Buffum and E. A. Petrocelli. 1994. Statistical

summary: EMAP -Estuaries Virginian Province - 1992. U.S. EPA Office of

Research and Development, Environmental Research Laboratory, Narragansett,

RI. EPA/620/R-94/019. 63 p. plus Appendices A–C.

Swartz, R. C., J. H. Bailey-Brock, W. J. Cooke and E. A. Kay. 2000. Benthic faunal

sampling adjacent to Sand Island ocean outfall, O’ahu, Hawai’i, SeptemberOctober 1999. Project Report PR-2000-06. Water Resources Research Center,

University of Hawaii, Honolulu. xii+209p.

Taylor, J. 1987. Quality assurance of chemical measurements. Lewis Publishers, Inc,

Chelsea, MI.

TN and Associates, Inc. 2001. Compiling Lists of Nonindigenous Species (NIS) from

the West Coast of the Unites States, Excluding San Francisco Bay. Report to

U.S. EPA/ORD/NCEA. 11 pages, plus appendices, plus spreadsheet.

U.S. EPA. 1994a. Methods for Assessing the Toxicity of Sediment-associated

Contaminants with Estuarine and Marine Amphipods. Office of Research and

Development, Environmental Monitoring and Systems Laboratory, Cincinnati,
133

OH. EPA 600-R-94-025. June 1994.

U.S. EPA. 1994b. Environmental Monitoring and Assessment Program (EMAP):

Laboratory Methods Manual - Estuaries, Volume 1: Biological and Physical

Analyses. Office of Research and Development, Environmental Monitoring and

Systems Laboratory, Cincinnati, OH. EPA/600/4-91/024. 321–324.

U.S. EPA. 2000. Clean Water Action Plan: National Coastal Condition Report. United

States Environmental Protection Agency, Office of Research and Development/

Office of Water. Washington D.C. EPA620-R-00-004

U.S. EPA. 2001a. Environmental Monitoring and Assessment Program (EMAP):

National Coastal Assessment Quality Assurance Project Plan 2001-2004. United

States Environmental Protection Agency, Office of Research and Development,

National Health and Environmental Effects Research Laboratory, Gulf Ecology

Division, Gulf Breeze, FL. EPA/620/R-01/002.

U.S. EPA. 1997. Environmental monitoring and assessment (EMAP) research

strategy. Office of Research and Development, Washington, D.C. 15p.

U.S. EPA 2001b. National Coastal Assessment: Field Operations Manual. EPA/620/R01/003. 71 pp.

U.S. General Accounting Office (GAO). 2000. Water Quality - EPA and State Decisions

Limited by Inconsistent and Incomplete Data. Report to the Chairman,

Subcommittee on Water Resources and Environment, Committee on

Transportation and Infrastructure, House of Representatives. Report GAO/RCED

00-54. pp. 78.

U.S. Geological Survey (USGS). 2000. Toxicity testing of sediments from the

BEST/EMAP Western Estuary Group monitoring study. Report Submitted by the

USGS Columbia Environmental Research Center, Marine Ecotoxicology

Research Station to the U.S. Geological Survey. Biomonitoring and

Environmental Status and Trends Program, 6006 Schroeder Road, Madison, WI,

10 pp. + 22 tables, 3 figures and 4 attachments.

U.S. Geological Survey (USGS). 2001. H4IIE bioassay-derived 2,3,7,8 -

tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ) in fish collected in 1999 from

small estuaries along the western coast of the United States. Report Submitted

by the USGS Columbia Environmental Research Center to the U.S. Geological

Survey. Biomonitoring and Environmental Status and Trends Program, 6006

Schroeder Road, Madison, WI, 16 pp. + 8 figures,10 tables.
134

Weisberg, S. B., J. B. Frithsen, A. F. Holland, J. F. Paul, K. J. Scott, J. K. Summers, H.

T. Wilson, R. Valente, D. G. Heimbuch, J. Gerritsen, S. C. Schimmel and R. W.

Latimer. 1992. EMAP- Estuaries Virginian Province 1990 demonstration project

report. U.S. EPA Environmental Research Laboratory, Narragansett, R.I.

EPA/600/R-92/100.