HARMFUL ALGAL BLOOMS AND HYPOXIA 

COMPREHENSIVE RESEARCH PLAN AND 

ACTION STRATEGY: AN INTERAGENCY 

REPORT

PRODUCT OF THE

National Science and Technology Council

Subcommittee on Ocean Science and Technology

February 2016
ii

EXECUTIVE OFFICE OF THE PRESIDENT

NATIONAL SCIENCE AND TECHNOLOGY COUNCIL

WASHINGTON, D.C. 20502

February 11, 2016

Dear Colleagues:

I am pleased to transmit to you Harmful Algal Blooms and Hypoxia Comprehensive Research Plan 

and Action Strategy: An Interagency Report, a report to Congress produced by the Interagency 

Working Group on the Harmful Algal Bloom and Hypoxia Research and Control Act (IWGHABHRCA). IWG-HABHRCA is organized under the National Science and Technology Council;

Committee on Environment, Natural Resources, and Sustainability; Subcommittee on Ocean 

Science and Technology. 

The 2014 reauthorization of the Harmful Algal Bloom and Hypoxia Research and Control Act 

(HABHRCA 2014; P.L. 113-124) acknowledges continued concerns related to harmful algal 

blooms (HABs) and hypoxia, extends the scope of the legislation to include freshwater HABs and 

hypoxia, and recognizes the need for further coordinated Federal action to address these issues.

Specifically, the legislation calls for a “comprehensive research plan and action strategy” and

assessments of harmful algal blooms and hypoxia, as well as an “integrated assessment on Great 

Lakes hypoxia and harmful algal blooms.” This report fulfills these requirements.

Sincerely,

John P. Holdren

Assistant to the President for Science and Technology

Director, Office of Science and Technology Policy
iii

About the National Science and Technology Council

The National Science and Technology Council (NSTC) is the principal means by which the Executive Branch 

coordinates science and technology policy across the diverse entities that make up the Federal research 

and development (R&D) enterprise. One of the NSTC’s primary objectives is establishing clear national 

goals for Federal science and technology investments. NSTC prepares R&D packages aimed at 

accomplishing multiple national goals. The NSTC’s work is organized under five committees: Environment, 

Natural Resources, and Sustainability; Homeland and National Security; Science, Technology, Engineering, 

and Mathematics (STEM) Education; Science; and Technology. Each of these committees oversees 

subcommittees and working groups that are focused on different aspects of science and technology. More 

information is available at www.whitehouse.gov/ostp/nstc.

About the Office of Science and Technology Policy

The Office of Science and Technology Policy (OSTP) was established by the National Science and 

Technology Policy, Organization, and Priorities Act of 1976. OSTP’s responsibilities include advising the 

President in policy formulation and budget development on questions in which science and technology 

are important elements; articulating the President’s science and technology policy and programs; and 

fostering strong partnerships among Federal, state, and local governments, and the scientific 

communities in industry and academia. The Director of OSTP also serves as Assistant to the President for 

Science and Technology and manages the NSTC. More information is available at 

www.whitehouse.gov/ostp.

About the Subcommittee on Ocean Science and Technology

The purpose of the Subcommittee on Ocean Science and Technology (SOST) is to advise and assist on 

national issues of ocean science and technology. The SOST contributes to the goals for Federal ocean 

science and technology, including developing coordinated interagency strategies, and fosters national 

ocean science and technology priorities, including implementation of the National Ocean Policy.

About the Interagency Working Group on Harmful Algal Bloom and Hypoxia 

Research and Control Act

In recognition of the challenges presented by harmful algal blooms and hypoxia, the Harmful Algal Bloom 

and Hypoxia Research and Control Amendments Act of 2014 (HABHRCA 2014, P.L. 113-124) emphasizes 

the mandate to advance the scientific understanding and ability to detect, predict, control, mitigate, and 

respond to these types of events. This legislation established the Interagency Working Group on HABHRCA 

(IWG-HABHRCA). It tasked the group with coordinating and convening Federal agencies to discuss HAB 

and hypoxia events in the United States, and to develop action plans, reports, and assessments of these 

situations.

About this Document

This document was developed by the IWG-HABHRCA. The document was published by OSTP.
iv

Acknowledgements

The IWG-HABHRCA thanks Patti Marraro, Kevin McMahon, and Catherine Polk of the National Oceanic 

and Atmospheric Administration for their help with editing and designing this report.

Special thanks and acknowledgment to the following subject-matter experts who contributed to the 

writing of this report: 

Environmental Protection Agency: Neil Chernoff, Armah de la Cruz, John Darling, Elizabeth Hilborn, Blake 

Schaeffer

Food and Drug Administration: Sara Handy, Chris Loeffler

National Oceanic and Atmospheric Administration: Eric Anderson, Suzanne Bricker, Quay Dortch, Alan 

Lewitus, Wayne Litaker, Rob Magnien, John Ramsdell, Steve Ruberg, Vera Trainer, Nathalie Valette-Silver

National Park Service: Ilya Slizovskiy, Tracy Ziegler

United States Army Corps of Engineers: Patrick Deliman

United States Department of Agriculture: Lisa Duriancik

United States Geological Survey: Neil Dubrovsky

United States Navy: Catherine Simons

Copyright Information

This document is a work of the United States Government and is in the public domain (see 17 U.S.C. §105).

Subject to the stipulations below, it may be distributed and copied with acknowledgement to OSTP.

Copyrights to graphics included in this document are reserved by the original copyright holders or their 

assignees and are used here under the government’s license and by permission. Requests to use any 

images must be made to the provider identified in the image credits or to OSTP if no provider is identified.

Printed in the United States of America, February 2016.
v

National Science and Technology Council

Chair 

John P. Holdren

Assistant to the President for Science

and Technology; Director,

Office of Science and Technology Policy

Staff

Afua Bruce

Executive Director

Committee on Environment, Natural Resources, and Sustainability

Co-Chairs

Tamara Dickinson Tom Burke

Principal Assistant Director for Environment and Science Advisor

Energy Environmental Protection Agency

Office of Science and Technology Policy

Kathryn Sullivan

Undersecretary for Oceans and Atmosphere;

Administrator of the National Oceanic and 

Atmospheric Administration

Department of Commerce

Staff

Lisa Matthews

Executive Secretary

Environmental Protection Agency

Subcommittee on Ocean Science and Technology

Co-Chairs

Richard W. Murray Fabien Laurier 

National Science Foundation Office of Science and Technology Policy

Richard Merrick

National Oceanic and Atmospheric 

Administration

Staff

Roxanne Nikolaus (Chief) Hilary Goodwin (Advisor)

National Science Foundation National Oceanic and Atmospheric 

Administration

Sarah Mesrobian (Assistant)

National Science Foundation
vi

Interagency Working Group on HABHRCA

Co-Chairs

Mary Erickson Ellen Gilinsky

National Oceanic and Atmospheric Environmental Protection Agency 

Staff

Caitlin Gould Linda Novitski

National Oceanic and Atmospheric National Oceanic and Atmospheric

Administration Administration

Subgroup Leads

Lesley D’Anglada (Harmful Algal Blooms) Stacey DeGrasse (Engagement)

Environmental Protection Agency Food and Drug Administration

Timothy Davis (Great Lakes) Rachel Melnick (Hypoxia)

National Oceanic and Atmospheric National Institute of Food and Agriculture

Administration

Members

Lorraine Backer Paula Bontempi

Centers for Disease Control and Prevention National Aeronautics and Science Administration

Tony Clyde Megan Butterworth Davidson

United States Army Corps of Engineers Bureau of Ocean Energy Management

Teri Rowles Erich Emery

National Oceanic and Atmospheric United States Army Corps of Engineers

Administration

Dave Garrison

Wayne Estabrooks National Science Foundation

United States Navy

Donna Myers

John Haynes United States Geological Survey

National Aeronautics and Space

Administration Steve Plakas

Food and Drug Administration

Fred Tyson

National Institute of Environmental Health Sciences
vii

Table of Contents

Executive Summary.......................................................................................................................................1

Harmful Algal Bloom and Hypoxia Research and Control Act .....................................................................1

Federal Accomplishments............................................................................................................................2

Report Purpose ............................................................................................................................................2

Recommendations.......................................................................................................................................3

1 - Report Motivation and Purpose .............................................................................................................5

1.1 - Research and Legislative Background .................................................................................................5

1.2 - Purpose of this Report.....................................................................................................................................6

2 - Engagement ............................................................................................................................................7

2.1 - Examples of Future IWG and Agency Engagement .............................................................................8

2.2 - Case Study - Lake Champlain...........................................................................................................................9

3 - Causes of HABs and Hypoxia..................................................................................................................10

Fig. 3.1 - Size of Bottom-Water Hypoxia in Mid-Summer, Gulf of Mexico.......................................................11

3.1 - Effects of Climate Change on HABs and Hypoxia...............................................................................12

4 - Threats Caused by HABs and Hypoxia ..................................................................................................13

4.1 - Ecosystem Impacts.............................................................................................................................13

4.2 - Human and Animal Health Impacts...................................................................................................15

Fig. 4.1 - Minimum Oxygen Requirements Chart.................................................................................................15

4.2.1 - Examples of Seafood Poisoning ......................................................................................................16

4.2.2 - Examples of Water and Air Poisoning ......................................................................................................17

4.2.3 - Complicating Factors ..................................................................................................................................17

4.3 - Socioeconomic Effects ..................................................................................................................................17

5 - Current Management Actions for HABs and Hypoxia: Successes Since 2004 .......................................20

5.1. - Prevention.........................................................................................................................................21

5.1.1. - Primary Prevention Strategies ......................................................................................................21

5.1.2. - Excess Nutrient Input ................................................................................................................................21

5.2 - Control ...............................................................................................................................................23

5.3 - Mitigation...........................................................................................................................................23

5.3.1 - Integrated Exposure Assessment....................................................................................................24

5.3.2 - Drinking Water Treatment..............................................................................................................24

5.3.3 - Toxin Detection Methods ...............................................................................................................25
viii

5.4 - Monitoring .........................................................................................................................................26

5.4.1 - Observing Systems..........................................................................................................................27

5.4.1.1 - Eyes in the Sky..............................................................................................................................28

5.4.1.2 - Eyes in the Water.........................................................................................................................28

5.4.1.3 - Eyes on the Coasts.......................................................................................................................28

5.4.2 - Models and Forecasts.....................................................................................................................29

Fig. 5.1 ......................................................................................................................................................................30

5.5 – Public Advisories ...............................................................................................................................31

6 - Challenges..............................................................................................................................................32

6.1 - Environmental, Economic, and Social Challenges..............................................................................32

6.2 - Monitoring Challenges.......................................................................................................................32

6.3 - Research and Modeling Challenges...................................................................................................33

6.4 – Human and Health Impacts Challenges............................................................................................34

7 - Research Plan and Action Strategy: Recommendations........................................................................36

8 - Integrated Assessment of Great Lakes HABs and Hypoxia....................................................................41

8.1 - Introduction .......................................................................................................................................41

8.2 - Causes of HABs and Hypoxia..............................................................................................................41

8.3 - Impacts of HABs and Hypoxia ............................................................................................................42

8.4.1 - Relevant Legislation and Funding Initiatives...................................................................................42

8.5 - Current Agency Actions and Successes: Prevention, Control, and Mitigation ..................................43

8.5.1 - Prevention.......................................................................................................................................43

8.5.2 - Control ............................................................................................................................................45

8.5.3 - Mitigation........................................................................................................................................46

9 - Conclusion ..........................................................................................................................................................48

Appendix 1 – HABs, Toxins, and their Effects.............................................................................................50

Appendix 2 - HAB-Related Human Illnesses................................................................................................52

Appendix 3 – Agency Activities on HABs and Hypoxia................................................................................55

Appendix 4 – Actions Taken Since 2008 HABHRCA Reports - HABs ...........................................................69

Appendix 5 - Actions Taken Since 2008 HABHRCA Reports - Hypoxia........................................................72

References ..................................................................................................................................................75

Abbreviations..............................................................................................................................................90

Glossary of Terms........................................................................................................................................92
ix
1

Executive Summary

The prevalence and duration of harmful algal blooms (HABs) and hypoxia (low-oxygen conditions) in the 

marine waters and freshwaters of the United States, including the Great Lakes, are generating public 

concern. From extended shellfish closures on the West Coast in 2015, to a larger-than-predicted hypoxic 

zone in the Gulf of Mexico, these events negatively impact resources across thousands of miles of the 

Nation’s coastal and inland waters, and represent some of the most scientifically complex and 

economically damaging aquatic issues. HABs and hypoxia pose a significant challenge to the ability to 

safeguard the health of the Nation’s coastal and freshwater ecosystems.

HABs and hypoxia have serious effects on a community’s social and public health. They may threaten the 

safety of seafood and drinking water, as well as air quality. HABs and hypoxia events may also result in 

disruption of subsistence activities, loss of community identity tied to aquatic-resource use, disruption of 

social and cultural practices, and lost revenue for lakefront and coastal economies that are dependent on 

aquatic/seafood harvest or tourism. 

Harmful Algal Bloom and Hypoxia Research and Control Act

In June 2014, Congress reauthorized the Harmful Algal Bloom and Hypoxia Research and Control Act 

(HABHRCA) by passing the Harmful Algal Bloom and Hypoxia Research and Control Amendments Act of 

2014 (HABHRCA 2014, P.L. 113-124). The reauthorization of HABHRCA acknowledged concerns related to 

HABs and hypoxia, extended the scope of the legislation to include freshwater HABs and hypoxia, and 

recognized the need for further coordinated action across the Federal sector to address these issues.

Additionally, the legislation called for Federal agencies to provide integrated assessments on the causes

and consequences of and approaches to reducing HABs and hypoxia nationally, with particular emphasis 

on the Great Lakes. Finally, the reauthorization included a specific focus on the needs of stakeholders, 

requiring that Federal agencies engage with stakeholders around the country.

HABs in Lake Erie (Photo courtesy of the National Oceanic and Atmospheric Administration)
2

Federal Accomplishments

Since the original authorization of

HABHRCA in 1998, and in many cases as a 

result of the legislation, the agencies 

involved in writing this report have made 

significant progress in addressing the 

causes of HABs and hypoxia, and in 

helping to mitigate the impacts of these 

issues. These achievements include:

• Establishing health advisories for

freshwater toxins, specifically the 

cyanobacterial toxins 

microcystins and 

cylindrospermopsin;

• Developing HAB and hypoxia 

forecast products through more 

comprehensive monitoring 

integrated with satellite coverage 

and modeling of ocean, coastal, 

and freshwater zones, to provide 

time for mitigation and response; 

• Developing and deploying lower 

cost, easy to use, and real-time 

sensors for early detection of 

hypoxia and HAB cells and toxins; 

and

• Improving understanding of the 

effects of HAB toxins on human 

and animal health.

Report Purpose

In recognition of the challenges presented 

by HABs and hypoxia, HABHRCA

emphasizes the mandate to advance the 

scientific understanding and ability to 

detect, predict, control, mitigate, and 

respond to these types of events. This 

legislation establishes the Interagency 

Working Group on HABHRCA (IWGHABHRCA). The legislation tasks the group 

with coordinating and convening Federal 

agencies to discuss HAB and hypoxia 

events in the United States, and to 

develop action plans, reports, and 

assessments of these situations.

Federal Response to HABs and Hypoxia

Federal response to HABs and hypoxia events requires 

considerable interagency collaboration. Some recent 

examples where agencies have worked together to 

address HABs and hypoxia are laid out below:

• The Gulf of Mexico annually experiences a 

hypoxic zone that varies in size. The size of the 

zone informs Federal, state, and local planning 

and management actions in the Mississippi River 

basin to reduce nutrient inputs that contribute to 

hypoxia. The Environmental Protection Agency 

(EPA) and the National Oceanic and Atmospheric 

Administration (NOAA) collaborated to map out 

the 2015 “dead zone,” determining that this 

year’s zone was 6,474 square miles. It was larger 

than the 5,052 square miles measured last year.

• Since late spring 2015, the U.S. West Coast has 

experienced an ongoing bloom of Pseudonitzschia, an algal species that can produce a 

toxin that impacts human and animal health.

Agencies including EPA, NOAA, and the Food and 

Drug Administration (FDA) have worked together 

to monitor and analyze the bloom, and to provide 

event-response assistance to local and regional 

communities.

• Many agencies collaborate to forecast and 

establish early warning systems for HABs in Lake 

Erie. In 2015, the United States Geological Survey 

(USGS), the National Aeronautics and Space 

Administration (NASA), EPA, and NOAA worked 

together to track the development of a bloom in 

Lake Erie using satellites as well as collected 

information on water quality, biomass size, and 

bloom toxicity levels. These agencies established 

an ongoing multi-agency research effort 

designed provide early warnings for freshwater 

nuisance and toxic algal blooms by using 

satellites that can gather color data from 

freshwater bodies during scans of the Earth. The 

project will improve the understanding of the 

environmental causes and health effects of 

blooms driven by cyanobacteria and 

phytoplankton.
3

This comprehensive HAB and hypoxia research plan and action strategy outlines Federal agencies’ roles 

and responsibilities for evaluating and managing HABs and hypoxia, agency successes since the 2008 

authorization of HABHRCA, and their management and response actions. This report also identifies 

remaining challenges and makes recommendations for actions to address these events. It draws from 

direct contributions from Federal agencies involved with managing and researching HABs and hypoxia, as 

well as from stakeholders from Federal, state, and local governments; academia; industry; nongovernmental organizations; and interested citizens. It incorporates those contributions to ensure that 

the recommendations align closely with and deliver products that address stakeholder needs.

Recommendations

This report recommends the following action plan for addressing HABs and hypoxia:

• Add to and improve scientific understanding of HABs and hypoxia, and their causes and effects, as 

well as improve testing and research methods. 

Currently, some of the biggest challenges to analyzing HAB and hypoxia dynamics include the 

inability to predict the onset of toxicity, a need to more specifically explain the influence that 

excess nutrients and other factors play in the occurrence and distribution of HABs and hypoxia, a 

lack of studies related to toxins in foods, the need to establish methods for suppressing or 

controlling HABs, the need for more science to understand the influence of a changing climate on 

HABs and hypoxia, and the need for tools to manage a limited availability of certified reference 

materials(CRMs) and validated detection and analysis methods. The IWG-HABHRCA recommends

the development of an interagency group specifically tasked with examining the possibility of 

developing CRMs and other standardized and validated detection and analysis methods.

• Strengthen and integrate new and existing monitoring programs. 

A thorough and scientifically-based monitoring program is critical to determining the location and 

extent of HABs and hypoxia occurrences, so that their causes can be controlled. Moreover, 

comprehensive monitoring is essential to providing baseline data for determining correlations of 

cause and effect, and is done by maintaining long-term records of environmental conditions to 

monitor future changes and provide data on how a changing climate may affect HAB and hypoxia 

events. In order to mitigate the impacts of HABs and hypoxia, it is also important to incorporate 

new technologies into monitoring systems that are used broadly; use observations to validate 

existing models; and identify key indicators that can be used to predict and identify HAB and 

hypoxia events at the local, regional, and national levels.

• Improve predictive capabilities by developing and enhancing HAB and hypoxia modeling 

programs; improve disease surveillance for human and animal exposure, illnesses, and death. 

Predictive models are critical for understanding HAB and hypoxia effects on ecosystems, and for 

addressing the prediction of, and response to, toxins in drinking and recreational waters.

Improving and expanding modeling efforts and remote satellite sensing can help to promote

technologies that minimize human and animal exposure and protect public health. Additionally, 

these improvements can help assess progress of management actions that inform mitigation 

strategies. A rapid response protocol is necessary for detecting and mitigating HAB toxins in 

humans and animals.

• Improve stakeholder communications, including having more effective and readily-available public 

advisories, stronger connections with susceptible communities, and a better understanding of the 

socioeconomic and health-related impacts of HABs and hypoxia. 
4

The first step to reducing HAB impacts on humans is to understand their causes, health effects,

and how best to communicate risks associated with HAB exposure. Communication among 

wildlife, veterinary, medical, and public health officials, as well as with the general public, needs 

to improve. Additionally, more should be understood and shared amongst these groups about the 

socioeconomic impacts of HABs and hypoxia to local, regional, and national areas.

• Continue and expand collaborations in research, management, and policy-related arenas.

Many of the research initiatives mentioned in this report have been made possible by 

collaborations between Federal agencies, as well as between these agencies and state and local 

entities, the public, and academia. Collaboration and information-sharing among all stakeholders

vastly increases the probability that people become educated about changes in their environment 

and can establish early measures to mitigate the effects of HABs and hypoxia.

Many, if not all, of these recommendations are interrelated. Improved scientific understanding of HABs 

and hypoxia can be gained in part through improved monitoring efforts. Modeling programs are 

dependent upon an understanding of the dynamics of these events, as well as long-term and robust 

monitoring efforts. Continued collaborations are necessary to achieve any of the aforementioned goals. 

The Nation’s marine waters and freshwaters provide many goods and services to communities and the 

country. They play critical roles in the nation's transportation, economy, and security. This report outlines 

needs, gaps, and successes, and provides a series of recommendations for addressing HABs and hypoxia 

in the United States to ensure continuity of goods and services for the future.
5

1. Report Motivation and Purpose

The marine waters and freshwaters of the United States, including the Great Lakes, are increasingly 

impacted by HABs and hypoxia. These phenomena, which routinely have negative impacts on resources 

across hundreds of miles of American coastal and inland waters, are scientifically complex and 

economically damaging aquatic issues. HABs and hypoxia challenge the ability to safeguard the health of 

the Nation’s coastal and freshwater ecosystems.

1.1. Research and Legislative Background 

In the early 1980s, concern about low levels of dissolved oxygen, which aquatic species absorb and require 

to live (Boyd, 2015), in coastal bodies of water in the United States led to the first national assessment of 

coastal hypoxia (Whitledge, 1985). This assessment found declining dissolved oxygen levels in many 

bodies of water, in part as a result of high nutrient levels (eutrophication). By the 1990s, serious and largescale water-quality problems, including HABs and hypoxia, had been identified, most prominently in the 

northern Gulf of Mexico, Lake Erie, the Chesapeake Bay, and Long Island Sound. These problems led to a 

national Federal assessment of eutrophication in 1999 (Bricker et al., 1999), which was updated in 2007 

(Bricker et al., 2007). These problems also motivated a Federal assessment of hypoxia in the northern Gulf 

of Mexico (Committee on Environment and Natural Resources (CENR), 2000; EPA, 2007), and passage of 

the Harmful Algal Bloom and Hypoxia Research and Control Act of 1998 (HABHRCA, P.L. 105-383). The 

HABHRCA specifically included HABs after numerous occurrences around the country made it clear that 

the government needed to take action to address this increasingly prevalent phenomenon. 

The HABHRCA was reauthorized as the Harmful Algal Bloom and Hypoxia Research and Control 

Amendments Act of 2004 (HABHRCA 2004, P.L. 108-456), which required reports that specifically 

addressed freshwater and marine HAB and hypoxia management to be submitted to Congress. In 2008, 

the Interagency Working Group on HABs, Hypoxia, and Human Health (IWG-HHHH)—tasked with 

responding to these requirements—submitted to Congress a HAB-management plan, “The Harmful Algal 

Bloom Management and Response: Assessment and Plan” (Jewett et al., 2008), which was soon followed 

by a more-detailed plan developed with wide community input, “The National Scientific Development, 

Demonstration, and Technology Transfer Plan on Reducing Impacts from Harmful Algal Blooms” (Dortch 

et al., 2008). The HABHRCA was reauthorized again in 2014 through the Harmful Algal Bloom and Hypoxia 

Research and Control Amendments Act of 2014 (HABHRCA 2014, P.L. 113-124). This reauthorization 

reconstituted the Interagency Task Force on HABs and Hypoxia as the Interagency Working Group on 

HABHRCA (IWG-HABHRCA, Table 1), which is organized under the National Science and Technology 

Council; Committee on Environment, Natural Resources, and Sustainability; Subcommittee on Ocean 

Science and Technology. The IWG-HABHRCA coordinates and convenes relevant Federal agencies to 

discuss HABs and hypoxia events in the United States, and develops needed reports and assessments on 

these topics. These assessments include updates to the two aforementioned reports produced under the 

last authorization. These updates have been incorporated into this report.
6

1.2. Purpose of this Report

This report provides Congress and 

stakeholders with a research plan and action 

strategy on HABs and hypoxia. It outlines the 

fundamental components of HAB and hypoxia 

management and response, and identifies 

challenges related to HABs and hypoxia events, 

ongoing and planned scientific research, and 

Federal agencies’ roles and responsibilities in

evaluating and managing HABs and hypoxia.

The report also describes recent scientific 

research that is the basis for improving how 

the country prevents and addresses these 

issues.

Information contained in this report was 

synthesized from a number of sources. The 

reports created under the previous HABHRCA 

provided solid background materials and 

served as a starting point. Federal agencies 

involved in research on marine, freshwater, 

and Great Lakes HABs and hypoxia contributed 

information from a wide range of resources, 

including scientific literature, project progress 

reports, and current and planned research and 

accomplishments. For further information on 

specific agency programs on HABs and 

hypoxia, see Appendix 3.

Additionally, stakeholder engagement—specifically mandated by the 2014 reauthorization of HABHRCA—

represented a key component of the IWG-HABHRCA’s efforts in drafting this report and carrying out its 

other functions. This report summarizes the IWG-HABHRCA’s efforts to interact with a wide range of 

interest groups, including relevant management and planning bodies, resource officials, economists, 

agricultural groups, tribal resource-management officials, scientists and public-health experts, industries 

affected by HABs and hypoxia, nonprofit groups, and the public. This report also offers recommendations 

for action that outline a path forward in effectively preventing and managing HABs and hypoxia events.

Table 1. Federal Departments and Agencies 

Comprising the IWG-HABHRCA. A key facet of the 

HABHRCA legislation is interagency collaboration. 

The IWG-HABHRCA is co-chaired by NOAA and EPA 

and is well-represented by a number of other Federal 

agencies with various interests and missions related 

to HABs and hypoxia. The IWG-HABHRCA has divided 

its work into four subgroups (HABs, Hypoxia, 

Engagement, and Great Lakes), each of which is 

headed by a different agency.

Department of Agriculture

Department of Commerce*

Department of Defense

Department of Health and Human Services

Department of the Interior

National Aeronautics and Space Administration

Environmental Protection Agency*

National Science Foundation

* Denotes co-chairmanship
7

2. Engagement

In the process of developing this report, the IWG-HABHRCA engaged with approximately 1,000 

stakeholders representing a wide range of interests, over 100 of whom submitted detailed input for 

consideration. Stakeholder representation included state coastal-management and planning officials; 

tribal resource-management officials; 

water- and watershed-management 

officials from both coastal and 

noncoastal states with source waters

that drain into water bodies affected 

by HABs and hypoxia; national park 

and Federal land managers; public

health officials; emergency

management officials; science and 

technology development institutions; 

economists; industries and businesses 

affected by marine and freshwater 

HABs and hypoxia events; scientists 

with expertise concerning HABs or 

hypoxia from academic or research 

institutions; and numerous other 

stakeholders, including members of

the general public. Moving forward, 

the IWG-HABHRCA will expand 

engagement efforts to include other 

relevant groups such as agricultural

producers, fishermen, and watershedadvocacy groups.

Stakeholder engagement occurred

primarily through a series of five

widely-advertised nationally- and regionally-focused webinars, during which participants had 

opportunities to interact with Federal representatives and ask questions before, during, and after each 

webinar presentation. An in-person stakeholder meeting co-funded by NOAA and the National Science 

Foundation (NSF) was held on April 14, 2015, at Bowling Green State University, OH, to discuss stakeholder 

needs specific to the Great Lakes region. Stakeholder engagement discussions related to HABs and 

hypoxia were held at conferences including Global Solutions to Regional Problems at Bowling Green State 

University, meetings and conference calls of opportunity (e.g., monthly calls of the National HAB 

Committee, a committee comprised of representatives from Federal and academic communities; the 

NOAA Ecological Forecasting Roadmap Meeting), and through direct engagement with agency-specific 

stakeholders (e.g., at the Interstate Shellfish Sanitation Conference). Finally, the IWG-HABHRCA 

established a specific email address for stakeholders to use to submit feedback: IWGHABHRCA@noaa.gov. 

Information submitted by stakeholders and through notes taken during the engagement activities were 

compiled, reviewed, and incorporated into this report as appropriate. Many contributions regarding the 

needs and challenges for mitigating, managing, and responding to HABs and hypoxia reiterated those 

contributed by Federal agencies. There were also numerous novel insights and ideas shared that were 

considered important and feasible for implementation. 

Figure 2.1. Example image of NOAA’s Lake Erie HAB tracker, a 

tool that combines remote sensing, monitoring, and modeling 

to produce daily 5-day forecasts of bloom transport and 

concentration. This product takes daily satellite imagery and 

real-time monitoring to estimate the current expanse and 

intensity of the bloom to assist in predicting where the bloom 

will travel and at what concentrations. These predictions can 

provide water intake managers timely information for making 

public health decisions.
8

A number of common themes emerged from the IWG-HABHRCA’s conversations and meetings.

Stakeholders specifically expressed the need for improved communication between all groups, including

better, faster, and more consistent messaging about threats; and better coordination and informationsharing among relevant groups. During discussions with stakeholders, the IWG-HABHRCA realized that in 

many areas around the country, tools and information already exist that could benefit stakeholders; such 

tools and information, however, are not used or communicated effectively. For example, the IWGHABHRCA received many questions and comments about a need for local and national citizen-science 

programs. Many individuals were unaware of the existence of nationwide opportunities such as the 

Phytoplankton Monitoring Network (PMN), or more localized examples like the Lake Champlain case study 

described in the next section. The stakeholder-engagement efforts described above gave the IWGHABHRCA opportunities to disseminate some of this information and connect groups with shared 

interests in HABs and hypoxia. It became clear nonetheless that a key element to addressing immediate 

and long-term local and national impacts of HABs and hypoxia is by improving when and how Federal 

agencies communicate with stakeholders and the public. Continuing to engage with stakeholders and 

maintaining communication pathways for research and resource sharing will be critical. 

In addition, stakeholders emphasized a need for platforms and strategies to communicate the seriousness 

of HAB and hypoxia events. Many stakeholders said that it was difficult to communicate the severity or 

potential severity of HAB or hypoxia impacts without standard, consistent messaging. Social media was 

often cited as a way to facilitate communication; many people, however, also indicated that the scope of 

reach of social-media platforms such as Facebook or Twitter is limited, especially with reaching certain 

populations or when attempting to effectively communicate the effects—not just the occurrence—of a 

HAB or hypoxia event. Stakeholders appreciated that there is a necessary balance of communication that 

has yet to be achieved. For example, providing too much information may lead to messages being ignored 

or rendered ineffective, whereas too little or infrequent messaging may result in messages being missed 

or misunderstood. IWG-HABHRCA engagement showed a clear need for inexpensive and more-widely 

available and used methods of communication in order to maximize the benefit of information provided 

to the public. Stakeholders also indicated that early warnings and predictions of HABs and hypoxia events

are among the most important tools available for helping communities, regions, and the country prepare 

for and mitigate any potential effects, including by making better decisions related to resource and 

funding management, and preventing human- and animal-health impacts. 

The extensive 2015 Pseudo-nitzschia bloom along the West Coast of the United States demonstrates the 

importance of improving public engagement by providing early warnings. The areas affected by this bloom 

are home to a number of commercially and socially important species, including razor clams and crabs.

The closure of the razor clam fishery in Washington State in May 2015 alone resulted in an estimated $9.2 

million in lost income. Advance knowledge allowed communities to find alternative pathways for 

acquiring resources that this income typically helps fund, including school supplies used by children in 

indigenous communities. Additionally, providing early information helped inform the public about 

potential dangers of Pseudo-nitzschia, and act accordingly—the early warning triggered the closure of a 

fishery, thereby preventing human illness and death. Providing communities with early warnings is 

essential in allowing sufficient time for planning, thereby reducing the short- and long-term impacts that 

HABs and hypoxia events may have on social and economic health.

2.1. Examples of Future IWG and Agency Engagement

The IWG-HABHRCA plans to build on engagement to date by continuing to interact with stakeholders.

Subsequent work products and progress reports will provide future opportunities to capture further 

stakeholder input. The IWG-HABHRCA and the individual agencies comprising it will also strive to leverage 

existing organizations and efforts aimed at informing or engaging specific stakeholder groups. For 

example, NOAA has significant infrastructure, resources, and stakeholder relationships that could be 
9

leveraged better in the engagement process, thus potentially helping to meet needs expressed by 

stakeholders. USDA has also worked to expand citizen engagement. A team of Federal and university 

researchers and agricultural extension educators from the 12 States along the Mississippi and Ohio Rivers, 

known as the Southern Extension and Research Activities Committee number 46 (SERA-46), has partnered 

with the HABHRCA-mandated Mississippi River/Gulf of Mexico Watershed Nutrient Task Force (the 

“Hypoxia Task Force”) and its members to increase efforts to manage complex natural-resource 

management issues. The group is working to expand and encourage the use of science-based nutrient 

management and other practices that help to reduce nutrient losses. SERA-46 is working to identify 

opportunities for states to share information, while also creating a network of leaders, including farmers,

who strategize about agriculturally based nutrient losses.

Likewise, the Office of Water of the EPA has developed a series of webinars, outreach materials, and 

online resources to build awareness of HABs and nutrient pollution, and to increase communication on 

the impacts HABs have on human health, ecosystems, and the economy. The efforts include building an 

online database to share information; tours of HAB sites for resource managers; and websites containing 

information about HAB-related research efforts as well as available policies and guidelines for HAB 

prevention, control, and mitigation.

2.2. Case Study – Lake Champlain

Vermont and New York are home to one of the country’s largest and best-known bodies of freshwater, 

Lake Champlain. The State of Vermont created the Lake Champlain Cyanobacteria Monitoring Program in 

response to the lake’s first HAB event, in 1999. The program is unique in that it combines qualitative and 

quantitative sampling and observation information from citizen scientists, water suppliers, and state staff

for HAB monitoring. The program sends 

out a weekly email to stakeholders in 

New York, Vermont, and Québec with 

relevant information and also posts data 

on the Vermont Department of Health’s 

cyanobacteria website. The program has 

been highly successful, monitoring 87 

locations around Lake Champlain and 

elsewhere in Vermont during 2014, and 

helping to protect boaters, swimmers, 

and other people who visit the lakes, as 

well as the region’s drinking water and 

the many businesses that depend on 

tourists to stimulate the economy.

During webinars and in email 

correspondence with members of the IWG-HABHRCA, representatives of the program made it clear that 

social media was one of the most helpful tools for disseminating information to the public. The members 

of the program have also indicated that there is a need for coordinated messaging related to HABs among 

local, state, and Federal authorities. They stated that their ability to reach and engage lake users within 

their region is in part attributable to the fact that they have been able to communicate easily with their 

stakeholders and partners using consistent language and easily understood messaging.

3. Causes of HABs and Hypoxia

HABs and hypoxia are caused by several factors acting together, and indeed, the two types of events are 

often linked. HABs are created by a small subset of naturally occurring microscopic or larger, plant-like 

Image 2.2. NOAA scientists study toxins (Photo courtesy of 

NOAA, National Ocean Service, National Centers for Coastal 

Ocean Science.)
10

cyanobacteria or algal species, including diatoms and dinoflagellates. Under certain conditions, these 

species can form large masses, or “blooms.” The algae in these blooms is ultimately consumed (typically 

by zooplankton) and recycled as fecal pellets, or dies naturally and sinks. Bacteria decompose these algal 

remains, a process which consumes dissolved oxygen contained in the water. When the rate of oxygen 

consumption in aquatic environments exceeds resupply, oxygen concentrations can quickly decline to 

levels insufficient to sustain most animal life, producing hypoxic conditions. Algal blooms also reduce 

water clarity and prevent sunlight from penetrating into the water and reaching submerged aquatic 

vegetation and benthic (seafloor) microalgae, causing them to release less oxygen that would normally 

help to replenish the water’s oxygen supply. In these ways, HABs can contribute to hypoxia (CENR, 2010).

Physical, chemical, and biological conditions also influence the development and persistence of HABs and 

hypoxia. Such factors include lake morphology, water-circulation patterns, light, temperature, grazing 

pressure from plant-eating fish, viruses, and microbial mechanisms (Kudela et al., 2015). Most hypoxia 

caused or exacerbated by human activities occurs in waters that are susceptible to hypoxia due to the 

physical structure of the body of water in question. In many temperate lakes, estuaries, and near-coastal 

waters, a vertical density gradient, or stratification, occurs in summer months. (In freshwater, the density 

gradient is driven by temperature; in estuaries and coastal areas, it is driven by a combination of 

temperature and salinity.) This density gradient isolates a layer of bottom water and sediments from what 

is usually a well-oxygenated surface layer. Density stratification of the water column can encourage the 

growth of some species, like dinoflagellates or cyanobacteria, that commonly trigger HABs, because of 

the organisms’ ability to move vertically and optimize their access to light and nutrients. Stratification also 

reduces the rate at which oxygen can replenish in deeper waters, meaning that decomposition of organic 

matter in bottom waters and sediments can rapidly deplete available oxygen in stratified bodies of water.

Nutrient pollution that stimulates algal blooms can result in much more organic matter reaching bottom 

waters, thus driving hypoxic conditions to much more severe levels than would occur naturally.

Hypoxia is not limited to stratified waters, however. Episodic hypoxia can occur in unstratified and shallow 

waters in areas of extreme algal production caused by nutrient pollution. In these increasingly common 

situations, algal respiration at night can lower oxygen to near zero. Because this type of hypoxia often 

occurs in shallow habitats that are preferred by fish populations, it can, in a matter of hours, trap fish and 

lead to large fish kills.

Hypoxia can also occur in near-coastal waters due to upwelling. Upwelling is the process by which warm, 

less-dense surface water is drawn away from along a shore by offshore currents and replaced by cold, 

denser water brought up from the subsurface. Upwelling of offshore ocean-bottom waters that are

permanently depleted of oxygen and lead to hypoxia. This phenomenon occurs due to strong and 

prolonged winds from a favorable direction, and it most commonly occurs in the Pacific Northwest.

While natural processes may cause HABs and hypoxia, they cannot completely account for the observed 

marked increase in the number and duration of HABs and hypoxia events around the world. The incidence 

of hypoxia globally has increased tenfold over the past 50 years, and by almost thirtyfold in the United 

States since 1960, with more than 300 aquatic systems recently experiencing hypoxia (Diaz and 

Rosenberg, 2008; CENR, 2010). Every state in the United States now experiences some kind of HAB or 

hypoxia event, in many cases annually, and previously unrecognized HAB species have emerged in some 

locations (Appendix 1).
11

The Northern Gulf of Mexico Hypoxic Zone

The northern Gulf of Mexico hypoxic zone is possibly the 

most widely known instance of hypoxia. It is described 

in detail in the Mississippi River/Gulf of Mexico 

Watershed Nutrient Task Force 2015 Report to 

Congress. The size of this hypoxic zone varies 

considerably from year to year, depending on natural 

and anthropogenic factors (Figure 2.1). The 2015 

hypoxic zone measured 6,474 square miles as of July 28-

August 3, approximately the size of Connecticut and 

Rhode Island combined (NOAA, 2015). Potential climate 

effects—including frequent, severe weather events;

prolonged drought; and early spring runoff—compound 

this variability within the reassessment timeline.

(See “The Mississippi River/Gulf of Mexico Watershed 

Nutrient Task Force 2015 Report to Congress” for 

further details.)
12

This increase is largely driven by ecological changes, food-web alterations, and the introduction of HAB 

species into new regions due to international commerce and water-flow modifications. Another important 

driver of HABs and hypoxia events is the export of large quantities of nutrients, such as phosphorus and 

nitrogen, and organic matter into coastal waters in areas of high population density or near developed 

watersheds (CENR, 2010). Excess nutrients and organic matter can stimulate harmful algal growth. 

Nutrient pollution can come from both direct (“point”) and indirect (“nonpoint”) sources, including

agriculture; municipal, and industrial wastewater; urban and suburban stormwater runoff; and 

aquaculture. In addition, atmospheric pollutants—especially nitrogen from fossilfuel combustion, volatilization of fertilizer and animal waste, and industrial outputs—can be deposited 

from the air to watersheds or directly into water, leading to increased nutrient levels. Overall, the greater 

the input of nutrients and organic matter into a body of water, then the greater the chance of hypoxic 

conditions developing and continuing.

3.1. Effects of Climate Change on HABs and Hypoxia

There is not a simple overarching relationship among climate change, HABs, and hypoxia. The character 

of HABs and hypoxia events can be affected in a variety of ways, including by increasing water 

stratification, altering the underwater-light environment, increasing dissolved carbon dioxide levels, 

decreasing aquatic pH, changing circulation patterns, altering nutrient availability, and modifying the rest 

of the biological community (Wells et al., 2015). Certain aspects of climate shifts—including changes in 

extreme-weather events, precipitation timing, and climate variability—are projected to increase 

anthropogenic sources of nutrients reaching water bodies, and exacerbating the impacts of HABs and 

hypoxia (Rabotyagov et al., 2014). This effect is likely to be compounded as increased human activity 

further elevates the amount of nutrient inputs. Climate change also leads to increases in freshwater 

temperature and stratification, increasing the likelihood of HABs and hypoxia events (Gowen et al., 2012; 

Paerl and Paul, 2014; Beaver et al., 2014; Wells et al. 2015).

The response of low-biomass HABs (and some high-biomass HABs) to climate change or increasing 

nutrient inputs is much more difficult to predict (Anderson et al., 2012; Bresnan et al. 2013; Davidson et 

al., 2013; Gowen et al., 2012; Wells et al. 2015). These HABs include many of the toxic marine and 

freshwater species that threaten human health. The difficulty arises because growth and toxicity of each 

species and strain responds differently to changing environmental conditions, and because each is a part 

of a larger plankton community. Studies of the impact of climate change on algal toxicity have 

demonstrated variable results on toxicological outcomes, either increasing or decreasing toxicity (Griffis 

et al., 2013), although research has also shown direct correlations between changing climate and a higher 

prevalence of human-health syndromes such as ciguatera fish poisoning (CFP) in some regions (Gingold 

et al., 2014).

Scientists believe, however, that climate change will result overall in net increases in HABs and hypoxia 

events, and that the spatial and temporal patterns of these events will change (CENR, 2010; Griffis et al. 

2013). For example, scientists hypothesize that, with continued shifts in temperatures and ocean patterns 

off the United States West Coast, HABs causing paralytic shellfish poisoning in Puget Sound, Washington,

will occur earlier and last longer, meaning that shellfish-harvesting closures imposed to protect human 

health will need to be extended (Moore et al., 2011; Melillo, 2014).

Better assessment of the current and projected future impacts of climate will require long-term,

retrospective records of phytoplankton and environmental conditions at specific locations, combined with 

observing systems to monitor future changes (Wells et al., 2015).
13

4. Threats Caused by HABs and Hypoxia

As concerns about HABs increased in the 1990s, the Federal Government began to devote greater 

attention to these issues (U.S. Senate Report 105-357; 1998). Since that time, under the direction of 

HABHRCA and guidance of National Plans (e.g., Marine Biotoxins and Harmful Algae: A National Plan;

Harmful Algal Research & Response National Environmental Science Strategy 2005-2015), scientists 

understand much more about the impacts of HABs and hypoxia events.

4.1. Ecosystem Impacts

The mechanisms by which HABs 

cause harm vary. While most algal 

species are not toxic (indeed, algal 

species are widely recognized as 

one of the cornerstones to life on 

Earth, and form the basis of the 

food chain as food for 

zooplankton and fish), there is a 

small but important subset of 

algal species that are known to be 

toxic (see Appendix 1). HABs 

caused by toxic algal species can 

kill fish or shellfish directly, and 

can sicken birds, marine 

mammals, and people who drink 

contaminated water and eat 

contaminated seafood if sufficient amounts of HAB toxins are ingested.

The mortality or relocation of algae-eating aquatic life can lead to or exacerbate the emergence of HABs, 

allowing the HABs to take over and dominate ecosystems. Such circumstances may occur independently 

of the effects of HABs and hypoxia (e.g., when coral bleaching leads to dead or dying coral reefs), or may 

be linked to these effects in a positive feedback loop that further reinforces hypoxic conditions (e.g., when 

hypoxia in an aquatic ecosystem reduces the populations of algae-controlling fish species, allowing algal 

blooms to continue unchecked) (Rosenblatt et al., 2013). Hypoxia-induced changes in sediment chemistry 

can also lead to nutrient release, further promoting HABs, especially in phosphorus-limited freshwater 

systems.

Hypoxia alone is known to have a wide range of detrimental impacts on aquatic species. Low 

concentrations of dissolved oxygen and toxic compounds can be lethal to aquatic species, and increases 

in hypoxia and HAB events have led to increased frequencies and magnitudes of fish kills (Thurston, 2002; 

Thronson and Quigg, 2008).

Image 4.1 Hypoxic “dead zone” in the Gulf of Mexico. (Photo courtesy of 

Nancy Rabalais, Louisiana Universities Marine Consortium)
14

HABs are an indicator of environmental 

degradation and are often associated with 

reduced biodiversity and greater 

environmental instability. Exposure to toxins

released by select HABs can affect 

physiology, pathology, behavior, and 

reproduction rates of organisms (Baganz et 

al., 1998; Greenfield et al., 2014). The direct 

and indirect effects of HABs and hypoxia can 

disrupt entire food webs, with extensive and 

varied impacts. In a coral-reef food web, for 

example, the coral reefs provide food 

sources and habitats for commercially

important fish species. Increasingly, 

however, excess nutrients—in conjunction 

with overfishing and ocean-temperature 

changes—are decimating corals faster than 

the corals can adapt for survival. Nutrients 

promote the growth of harmful macroalgae 

that overgrow and kill corals. Normally, 

herbivorous fish eat these macroalgae, 

allowing space for larval corals to settle and 

regrow. Overfishing reduces the numbers of these fish such that the fish populations cannot control the 

overgrowth of the HABs (Rosenblatt et al., 2013). Exceedingly high summertime temperatures also are 

causing massive coral bleaching (mortality) events. These mass-mortality events create open space on the 

reef ideal for colonization by the faster-growing HABs, resulting in a further loss of viable coral habitat.

Because coral reefs act as physical barriers that serve as 

coastline stabilizers and storm-surge buffers, coral loss

can have catastrophic effects on ecosystems and coastal 

communities. HABs have already damaged coral reefs 

that play an important role in dampening coastal storm 

impacts in the United States (HARRNESS, 2005; Riegl et 

al., 2012).

HABs also adversely affect other shoreline-stabilizing 

organisms. Dense HABs can directly inhibit growth of 

beneficial vegetation, such as seagrasses, that often 

serve as storm buffers, by blocking sunlight penetration 

into the water column and by fouling beaches. HABs 

harm shoreline-stabilizing oysters by inhibiting growth 

and reproductive rates, and ability to fight off disease 

and other stressors (Lopez et al., 2008b).

HABs and hypoxia can also have non-lethal effects, 

including shifts in spatial distribution of organisms, changes in community structure caused by migration

of fish and other mobile organisms like shellfish, and alteration or blockage of normal migration routes of 

fish and invertebrates (Craig, 2012; Craig and Bosman, 2012; Roman et al., 2012; Kraus et al., 2015). These 

effects can alter the availability of fish and other organisms that are important either as sources of food 

or sources income generated by industries such as fishing or tourism. While the specific concentrations 

(Figure 3.1) of low dissolved oxygen that affect animals vary by species, effects generally appear when 

Image 4.3. Fish kill from September to 

November 2009 HAB event, Mustang Island, TX.

(Photo courtesy of Rick Henrichs)

Image 4.2. Digging for razor clams along the coast of 

Washington. This fishery and other shellfisheries are affected 

by HABs, costing millions of dollars in lost revenue. In May

2015, the Washington razor clam fishery closed due to a large 

Pseudo-nitzschia bloom, resulting in an estimated $9.2 million 

in lost income. (Photo courtesy of Vera Trainer, NOAA)
15

oxygen levels drop below about 3 milligrams/liter (Diaz and Rosenberg, 1995; Ritter and Montagna, 1999; 

Breitburg et al., 2001; Rabalais et al., 2001; Karlson et al., 2002).

4.2. Human and Animal Health Impacts

HABs can adversely affect the health of all animals and some plants, with the potential to seriously harm 

or kill thousands of organisms every time blooms occur. Indeed, sick or dying animals are often the first 

indicators of a toxic bloom and may serve as harbingers for other potential harmful effects. HAB-related 

deaths of marine animals, including manatees, seals, whales, sea turtles, and sea birds, can involve 

hundreds of individuals during each event (NOAA, 2004). HABs have been the most common cause of 

unusual mortality events (UMEs) in marine mammals over the last 20 years (Gulland and Hall, 2007; 

Simeone et al., 2015). Blooms commonly cause fish kills and bird mass-mortality events, and can 

sometimes poison pet dogs and livestock.

It is less well-known whether, and to what degree, the exposures to HAB toxins described above cause

long-term health effects in humans, such as liver disease, cardiovascular disease, developmental defects, 

or neurobehavioral illness. Additional research into the effects of exposure to HAB toxins will help to 

further describe the acute and longer-term health risks to humans and other animals. Humans and 

animals may be exposed to algal toxins via consumption of contaminated seafood, dietary supplements

Figure 4.1. Minimum Oxygen Requirements Chart (Source: 2010 Hypoxia Scientific Assessment)

Hypoxia means “low oxygen”. In aquatic and marine systems, low oxygen generally refers to a dissolved oxygen 

concentration less than 2 to 3 milligrams of oxygen per liter of water (mg/L), but sensitive organisms can be 

affected at higher thresholds (4.5 mg/L). A complete lack of oxygen is called anoxia.

Hypoxic waters generally do not have enough oxygen to support fish and other aquatic animals, and are 

sometimes called dead zones because the only organisms that can live there are microbes. The criteria set for 

health of various species in Chesapeake Bay are a good example of how one definition for hypoxia is not 

possible (EPA, 2003).
16

derived from cyanobacteria, or foods grown with contaminated irrigation water. Exposure may also occur 

through drinking water, inhalation, skin contact, or accidental ingestion of water while engaging in 

recreational activities. A summary of acute or short-term human health consequences of HAB toxin 

exposure can be found in Appendix 2.

Even blooms that are not toxic can cause damage by 

forming masses that suffocate fish by clogging their 

gills, block light from bottom-dwelling plants, (Lopez 

et al., 2008a, 2008b; Delegrange et al., 2015; Kudela 

et al., 2015), clog the water-supply intakes in watertreatment plants (Caron et al., 2010), and adversely 

alter food webs by displacing beneficial species. 

(Lopez et al., 2008b; Delegrange et al., 2015). When 

HABs lead to hypoxia, they can stress or kill many 

organisms, including fish and shellfish, their 

predators, and the prey they depend on. While most 

mobile organisms are able to avoid hypoxic waters by 

swimming or crawling away, organisms that are 

unable to move or are otherwise trapped within an 

hypoxic zone become physiologically stressed and can 

die if exposure is prolonged or severe (CENR, 2010).

4.2.1. Examples of Seafood Poisoning

HAB toxins are commonly passed through aquatic food webs: from algae to filter-feeders to fish to top 

predators, including people. Through this process, the toxins may accumulate to levels that can cause

various poisoning syndromes, which in turn cause illness or even death in humans or other consumers 

(Lewitus et al., 2012; reviewed in Munday, 2014).

The shellfish-poisoning syndromes are known as paralytic (PSP), diarrhetic (DSP), neurotoxic (NSP), 

azaspiracid (AZP), and amnesic (ASP) shellfish poisoning. Except for ASP, which is produced by certain 

diatoms (Bates et al., 1989), all are caused by biotoxins synthesized by a class of marine algae called 

dinoflagellates. Significantly, DSP appears to be an emerging threat, with shellfish-harvesting closures as 

a result of DSP reported in 2008 off the coast 

of Texas (Deeds et al., 2010), and other DSP

events occurring in 2011 in Washington 

(Trainer et al., 2013) and British Columbia 

(Taylor et al., 2013). Dealing with this newly

emerging group of toxins is a current challenge 

for several impacted state programs. Another 

prominent human syndrome, CFP, is caused 

when humans consume fish contaminated 

with accumulated ciguatoxins, the precursors 

of which are produced by microalgae that 

grow on seaweeds and other surfaces in coralreef communities (Lehane and Lewis, 2000).

4.2.2. Examples of Water and Air

Image 4.4. Live sea scallops harvested from 

Georges Bank during an assessment of spatial 

distributions of paralytic shellfish poisoning 

toxins in offshore bivalves. (Photo courtesy of 

Stacey DeGrasse, U.S. Food and Drug 

Administration)

Agencies work to track, reduce, and prevent HABrelated illness

The Centers for Disease Control and Prevention 

developed a HABs module for the National Outbreak 

Reporting System (NORS) to accumulate clinical data on 

people and animals poisoned by HABs. This system has 

recorded HAB-associated human illness after recreational 

water exposure in the last few years (Yoder et al., 2004; 

Dziuban et al., 2006; Hilborn et al., 2014). Reports 

described gastrointestinal, dermal, and respiratory signs 

and symptoms. No algal bloom-associated waterborne 

disease outbreaks associated with drinking water have 

been reported through NORS to date.
17

Poisoning

HAB toxins can be released directly into the water or air, 

either naturally through processes like algal cells breaking up 

and releasing toxins due to water turbulence, or through 

human activities such as water treatment or power boating.

For instance, in the case of one of the most well-known types 

of HAB events, toxic red tides in the Gulf of Mexico (Karenia 

brevis), HABs release toxins into sea-spray aerosols. These 

aerosols are particularly problematic at beaches, as they can 

cause respiratory distress to local residents, lifeguards, and 

beachgoers. Inhalation of these aerosols leads to respiratory 

irritation, coughing, and other symptoms (Backer, 2009).

Exposure from HAB toxins released into the air above fresh 

waters is a potential problem, but is less-well characterized.

Most health effects associated with inhalational exposure to 

freshwater HABs have occurred among those recreating on or 

in HAB contaminated water (Giannuzzi et al., 2011; Hilborn et 

al., 2014).

4.2.3. Complicating Factors

One complicating factor in assessing the health impacts of HABs is the fact that not all toxin-producing 

algae always release their toxins into surface waters. For example, anatoxin-a and microcystin toxins tend 

to be found intracellularly and are only released when algal cells rupture or die. Conversely, a large 

amount of cylindrospermopsin is released into the water by algae that are living. Hence the presence of 

toxin-producing algal species is not always independently indicative of the extent of human and animal 

health risks. As resource managers work to treat water effectively, they are challenged to consider 

detailed information such as algal growth patterns, environmental conditions, dominant species of algae, 

and the toxicological properties of relevant compounds. 

Furthermore, in addition to directly inducing illness, HAB toxins can interact with other internal and 

external agents to alter the course of disease. Microcystins, a type of toxin produced by some HABforming cyanobacteria, have been shown to initiate and promote liver cancer in laboratory animals (Fujiki 

and Suganuma, 2011), and epidemiological studies in China and Serbia suggest that microcystins may have 

contributing roles in the development of human primary liver cancer (World Health Organization, 2008; 

Svircev et al., 2009; Tian et al., 2013).

4.3. Socioeconomic Impacts

HABs and hypoxia also may have serious effects 

on a community’s social and economic health. It 

is important for cost-benefit analyses and risk 

assessments to include a clear explanation and 

reliable estimate of the economic and social 

costs of HAB and hypoxia events, as well as a 

discussion of the populations that these costs 

affect most. Social impacts of HABs and hypoxia

events are generally much more difficult to 

quantify than economic impacts, although 

efforts are underway to address this challenge.

Ongoing studies through NOAA and the National 

Image 4.5. Seaweed bloom on tidal flats 

at low tide, Edgar M. Tennis Preserve, 

Deer Isle, Maine. (Photo courtesy of NOAA 

Photo Library; Image ID: 2869;

Photographer: Captain Albert E. Theberge,

NOAA Corps (ret.))

Social Impacts of HABs

In August 2014, Lake Erie experienced a bloom near 

the intake to the drinking water treatment plant 

serving the city of Toledo, Ohio. Toledo issued a “do 

not drink or boil advisory” that affected nearly 

500,000 customers due to the presence of cyanotoxin

that exceeded the safe drinking water threshold 

recommended by the World Health Organization 

(WHO) (Wilson 2014).
18

Institutes of Health’s National Institute of Environmental Health Sciences (NIEHS) to identify animal and 

human populations at higher risk for exposure to and adverse effects from HABS and hypoxia events, for 

instance, could support improved analysis of social impacts.

Although no national estimate of the economic costs of HABs has been conducted, coastal and inland HAB 

events in the United States have resulted in millions of dollars in costs to communities, including losses in 

income from commercial fishing, recreation, and tourism industries, public health costs of illness, and 

expenses for monitoring and management (Lopez et al., 2008a, 2008b). A 2015 EPA report evaluated the 

costs associated with controlling nutrients at their sources, as well as those associated with the impacts 

of nutrient pollution for a number of economic sectors, with a focus on HABs and hypoxia. The report 

found that in Ohio, a persistent HAB in a lake caused communities to lose between $37 million and $47 

million in tourism dollars between 2009 and 2010. Another HAB off the coast of Maine led to $2.5 million 

in losses of soft shell clam harvests from April to August 2005 (EPA, 2015a). It should be noted, however, 

that there is dissention within the scientific community of the methodologies used to derive cost 

estimates for coastal HABs (Hoagland and Scatasta, 2006; Grimes et al., 2012; EPA, 2015a).

These costs can manifest in a variety of ways—including

public-health costs, commercial-fisheries losses, recreation

and tourism losses, and monitoring and management costs—

and can differ between freshwater and coastal HABs.

Freshwater HABs can impose substantial costs when such 

events contaminate sources of drinking water, leading to high

public-health costs as a result of water testing and treatment, 

provision of alternative drinking-water sources, and loss of 

municipal revenue due to water-use bans. HABs and hypoxia 

can also affect food and drug production, with associated loss 

of revenue. Toxic HABs pose a potential hazard for dietary 

supplements containing cyanobacteria, meaning that 

government agencies (such as the Food and Drug 

Administration) and private companies have to develop and 

use costly detection techniques to prevent toxins from 

entering the commercial market. Livestock can die after drinking water contaminated by HAB toxins, and 

algal blooms may decrease fish production, cause off-flavor and objectionable odors in fish, and lead to 

fish kills because of oxygen depletion. Indeed, hypoxia can have large economic impacts on the fishing 

industry, through fish mortality, reduced growth, and reduced fish reproduction, as well as by increasing 

the time needed to fish to compensate for decreased fish availability. Hypoxia has been linked to the 

collapse or impairment of a number of commercially important fisheries worldwide (Mee, 2006); it can 

be challenging, however, to effectively separate the effects of hypoxia from the effects of overfishing 

(Breitburg et al., 2009). It is likely that the two causes are linked: that hypoxia decreases productivity and 

resilience of exploited populations, making them more vulnerable to collapse in the face of heavy fishing 

pressure, as was evidenced in a study of Gulf of Mexico brown shrimp (Smith et al., 2014).

In coastal areas, excess nutrients and warmer water temperatures can promote large offshore macroalgal 

(seaweed) blooms (Figure 3). These blooms are driven onto shore by prevailing currents and winds, 

particularly during storms. When this happens, beaches, shorefront properties, and marinas can become 

inundated in rotting seaweed, which can be three or more feet deep. This huge accumulation of biomass 

causes myriad problems, including fouling small-boat motors, deterring tourism, and degrading 

property values. The cleanup and disposal costs associated with these blooms constitute a significant 

economic loss which must be borne by local governments and individual property owners. These costs 

Image 4.6. Environmental sample 

processor to detect harmful algae and 

their toxins. (Photo courtesy of NOAA)
19

have risen over time as macroalgal blooms have increased in intensity and frequency (Lapointe et al., 

2004).

In addition to imposing economic impacts, HABs and hypoxia can disrupt coastal communities socially and 

culturally; for instance, by harming fisheries in communities that rely on subsistence fishing as a food 

source and livelihood, as is the case for Native American communities around the country (Lewitus et al., 

2012). HABs and hypoxia also disrupt other ecosystem services1 that underpin social and cultural health 

(Lipton and Hicks, 1999, 2003; Bricker et al., 2006), although these effects are complex and can be difficult 

to fully capture and quantify.

 

1 Ecosystem services are the contributions that a biological community and its habitat provide to our day-to-day lives, including 

providing food sources, recreation opportunities, and carbon sinks.
20

5. Current Management Actions for HABs and Hypoxia: 

Successes Since 2004

Through the 1970s, organic-matter loading from sewage and industrial discharge was a primary cause of 

eutrophication in the United States, leading to HABs and hypoxia events (Diaz and Rosenberg, 2011; 

Pellerin et al., 2014). Actions following the passage of the Clean Water Act (CWA) in 1972 reduced pointsource organic loading and, later, reduced point-source phosphorus and nitrogen loading, contributing to 

some improvements in hypoxia problems. With improvements in nutrient contributions for these point 

sources, nonpoint runoff of nutrients became a more significant component of water-quality 

deterioration in inland and coastal systems in the United States as development and agricultural 

production increased (Vitousek et al., 1997; Bricker et al. 1999, 2007; Diaz and Rosenberg, 2011; Pellerin 

et al., 2014). Recently, efforts have been made to address the proliferation of nonpoint sources of nutrient 

pollution, such as agricultural, urban, and suburban runoff through regulatory and voluntary means.

Effective management of HABs and hypoxia is critical to minimizing negative impacts on living resources; 

human health; and local, regional, and national economies. The status of various management 

approaches in the field was summarized in the reports produced per the 2004 HABHRCA reauthorization,

2

and the following general recommendations for how to improve HAB prediction and response were made:

• Conduct research focused on the development, demonstration, and technology transfer of 

methods for the prevention, control, and mitigation (PCM) of HABs and HAB impacts; 

• Develop a coordinated, regionally organized HAB event response; and 

• Ensure availability of core infrastructure to support HAB research and response.

The concepts developed through these plans—i.e., prevention, control, and mitigation—are key to 

managing HABs and hypoxia. Prevention refers to environmental-management actions taken to reduce 

the incidence and extent of HABs and hypoxia events. Control (or suppression) refers to strategies that 

directly kill HAB cells or destroy their toxins, physically remove cells and toxins from the water column, or 

limit cell growth and proliferation. These strategies aim to reduce the impacts of HABs and hypoxia events

on people and commerce by targeting the immediate causative agents of these events. Mitigation refers 

to responding to an existing or ongoing bloom by taking steps to restrict, inhibit, or prevent associated 

undesirable impacts on the environment, human health, or human economies and communities.

Prohibiting seafood that is contaminated with HAB toxins from entering commerce is an example of a 

management strategy to mitigate human-health impacts. Mitigation is the area of HAB management 

where the most immediate potential exists to reduce impacts, given that many such activities are already 

underway (Seltenrich, 2014).

The Federal agencies addressing critical components of threats posed by HABs and hypoxia have made 

many advances since the 2004 authorization of HABHRCA. In response to community and policymaker 

needs, NOAA has established a research program focused on preventing, controlling, and mitigating HABs.

Since 2004, HAB- and hypoxia-forecasting systems are in place in several locations around the country, 

and agencies have developed more expansive and detailed monitoring and detection systems. These 

systems have enabled timely closing and reopening of shellfish beds, recreational areas, and drinkingwater sources to avoid harmful impacts to people, marine mammals, and the economy. Federal efforts 

have helped advance understanding of nutrient-loading mechanisms, helping managers assess the 

efficacy of current nutrient-reduction practices and improve nutrient management and management 

 

2 http://coastalscience.noaa.gov/research/habs/habhrca
21

programs. Additionally, the efforts have led to the development of effective strategies for modeling and 

mitigating hypoxia. Federal activities have also helped raise awareness of HABs and hypoxia among

external stakeholder groups, most notably among groups outside of academic and research sectors, 

thereby facilitating collaborative, cross-sectoral efforts to reduce the impacts of HABs and hypoxia on 

humans and animals. 

This section provides some examples of progress in HAB and hypoxia prevention, control, mitigation, and 

monitoring that has been made since 2004. Additional information about specific activities is contained 

in Appendices 4 and 5.

5.1. Prevention 

5.1.1. Primary Prevention Strategies

Although regulating the factors known to contribute to the development of HABs and hypoxia is often 

difficult and not always feasible, certain contributing factors—including changes in land use, increased 

nutrient loadings, altered hydrology, introductions of new species, and increased aquaculture in HAB- and 

hypoxia-prone areas—can be regulated to some extent. Management strategies evolve as knowledge 

grows. Primary strategies for controlling HABs and hypoxia currently include the following: 

• Minimizing land-based nutrients flowing into coastal and inland waters;

• Reducing nitrogen emissions in the airshed to reduce precipitation-related deposition of nitrogen 

compounds from the air to the land;

• Aerating systems and flushing dams to prevent hypoxia; and

• Reducing new introductions of algal species through genetic control (genetically engineering 

species that are purposely introduced into an ecosystem in order to alter the environmental 

tolerances, reproduction, or other processes of undesirable species) and environmental control 

(manipulation of an ecosystem environment, such as altering ecosystem habitat to disfavor 

growth of undesirable species.

5.1.2. Excess Nutrient Input

Developing effective strategies for preventing HABs and hypoxia requires a sufficient understanding of 

the causes of these issues. One cause that has attracted particular focus is excess nutrient input. Excess

input of nutrients—including nitrogen, phosphorus, and legacy nutrients--is one of the primary causes of

HABs and hypoxia events, and can exacerbate the development of HABs or hypoxia in systems that are 

already prone to these issues. There are several nutrient drivers of HABs and hypoxia that are expected 

to increase with the growing human population, including intensification of agriculture, conversion of land

for development, and higher energy consumption that results in greater nitrogen air emissions. Aging 

water and sewage systems can also leak nutrients that influence the development of HABs and hypoxia 

(Paerl et al., 2011), and there is emerging research that discharge of submarine groundwater—that is, 

water located underneath soil and rock in marine ecosystems—may contribute to hypoxia in coastal 

waters (Moore, 2010; McCoy et al., 2011). The key to reducing nutrient drivers of HABs and hypoxia is to 

develop and implement cost-effective and scientifically sound nutrient-reduction strategies in rivers and

streams, lakes and reservoirs, and estuaries and near-coastal marine waters.

Currently, there are efforts across the country to better understand the causes and consequences of 

excess nutrient input, including how complex interactions among groundwater systems, surface-water 

systems, biogeochemical processes, and other factors affect nutrient loading; nutrient transport through 
22

water systems (including evaluating changes in upstream ecosystems that can impair areas downstream); 

and how the contributions of atmospheric nitrogen and groundwater nutrients to the development of 

HABs and hypoxia. NOAA’s predictive modeling for HABs and hypoxia uses an integrated approach, which 

consists of using satellite images; remote sensing buoys; a comprehensive monitoring program in Lake 

Erie and Saginaw Bay, Lake Huron; and advanced genetic techniques to understand the long and shortterm seasonal dynamics of HAB events. The data is used to inform predictive models used by key Great 

Lakes stakeholder groups, such as drinking water managers. 

The USDA’s Conservation Effects Assessment Project (CEAP), for instance, examined the effects of existing 

conservation activities on water quality and soil resources in edge-of-field and large river basins—such as 

the Mississippi River Basin, Great Lakes, and Chesapeake Bay—and in small watersheds. USDA has also

estimated needs for conservation treatments to reduce soil erosion and nutrient transport in vulnerable 

ecosystems. Projects like these provide information that communities, resource managers, and decision 

makers need to make sustainable water-resource decisions. As a part of its larger forest-restoration and 

sustainable-forestry programs, the USDA Forest Service is maintaining and promoting forested buffer 

strips along streams to reduce nutrients inputs and manage aquatic HABs and hypoxia.

Other efforts focus on enhancing continuous measurement of nutrient concentrations, which improves 

understanding of HABs and hypoxia by more accurately quantifying nutrient loads in water bodies, giving 

insight into processes that control nutrient variability in freshwaters, and providing real-time data for early 

detection of trends. The U.S. Geological Survey (USGS), in partnerships with other state and Federal 

agencies, is using advanced optical-sensor technology to accurately track nitrate levels on an hourly basis 

at 104 small streams and rivers nationwide, including more than 40 sites throughout the Mississippi River 

Basin. Better nutrient measurement also improves the accuracy of, and reduces the uncertainty in, models 

used to calculate nutrient loading in coastal and other aquatic environments. Because these models are

typically based on relationships between streamflow and measurements of nutrient concentration, 

insufficient nutrient data can compromise model reliability, which is particularly problematic during 

extreme climatic periods. For example, examining nitrate data collected continuously in the Mississippi 

River basin during the drought-to-flood years of 2012-2014 showed that the concentration–discharge 

relationships for these events were not well-represented by historical data (Pellerin et al., 2014).

Progress on addressing nutrient pollution has occurred through the work of the Hypoxia Task Force and 

the creation of Annex 4 of the Great Lakes Water Quality Protocol of 2012, an agreement between the 

United States and Canada related to managing, protecting, and restoring the waters of the Great Lakes. 

Annex 4 specifically outlines an action plan for reducing nutrient inputs in order to reduce HABs (Great 

Lakes Water Quality Protocol, 2012). Additionally, in August 2015, President Obama signed into law the 

Drinking Water Protection Act (P.L. 114-45), which required EPA to develop and submit to Congress a plan 

evaluating the risk of harmful cyanotoxins to human health. The plan—“Strategy Submitted to Congress 

to Meet the Requirements of P.L. 114-45,” produced in November 2015—includes steps and timelines for 

evaluating the human-health risk from drinking water contaminated by algal toxins; establishing a list of 

algal toxins that may have an adverse effect on human health; determining whether to publish health

advisories for algal toxins; establishing guidance regarding feasible analytic methods, monitoring 

guidance, and treatment options (including source-water protection); and outlining a Federal strategy for 

entering into cooperative agreements with and provide technical assistance to affected 

states and public-water systems (EPA, 2015c). The Drinking Water Protection Act also directs EPA to 

assemble and publish information from each Federal agency that has examined or analyzed cyanobacteria 

or algal toxins, or addressed public health concerns related to harmful algal blooms, and identify 

information gaps.
23

5.2. Control

Chemical, biological, physical, and environmental controls can be used to regulate or suppress HABs and 

hypoxia (Jewett et al., 2008). Since all control strategies involve modifying the natural environment, it is 

necessary to carefully consider the positive and negative impacts of deploying a given control in a given 

setting. For example, controlling HABs using 

bloom suppression is only useful and 

economically feasible on small scales (e.g., 

aquaculture settings, small water bodies), 

where the environmental and economic 

impacts of the HABs greatly outweigh those 

of bloom-suppression control method.

5.3. Mitigation 

Currently, HAB and hypoxia mitigation is 

more practically feasible than HAB and 

hypoxia prevention or control. Effective 

mitigation requires early warnings of the 

emergence or increased risk of HABs or 

hypoxia. Early warnings, in turn, require 

monitoring of the input of nutrients into coastal and inland waters, including monitoring both levels of 

nutrients in water bodies and in their primary source waters. Early warnings also depend on models that 

predict the likelihood of HAB or hypoxia development based on observed conditions. For instance, EPA 

has developed models that predict chlorophyll a, or “trophic state,” for nearly all lakes in the United States 

in order to determine pollution levels and the likelihood of cyanobacteria presence in inland waters 

(Hollister et al., in review).

Early warnings allow managers to mitigate the health and economic impacts of HABs or hypoxia events 

by making preparations in advance, focusing sampling in critical areas, and issuing advisories warning the 

public of potential impending consequences. Mitigating the negative human-health impacts of HABs 

involves management strategies for ensuring that seafood contaminated with HAB toxins is identified and 

prevented from entering into interstate commerce. For instance, FDA produces a “Hazards Guide” to help 

with the early identification of HAB toxins in seafood, and to help seafood processors develop “hazardanalysis critical control-point” plans. These plans are designed to prevent seafood contaminated with HAB 

toxins from reaching consumers. One example of mitigation of economic impacts comes from the State 

of Washington, which in spring 2015 issued early warnings of domoic acid contamination in razor clams, 

caused by an outbreak of Pseudo-nitzschia on the West Coast of the United States. These early warnings 

led to and allowed for selective beach openings, saving at least $3 million per year for the State’s coastal 

fisheries by providing more accurate and real-time information on the presence of the algae and toxin 

(Dyson et al., 2010).

Federal agencies have made some important progress in HAB and hypoxia mitigation, including limiting 

impacts on human health. For instance, scientists in the FDA’s Center for Food Safety and Applied 

Nutrition have identified and characterized HAB toxins in seafood and developed analytical methods for

monitoring and controlling these toxins. The FDA has made critical advances in food safety by identifying 

the additional fish species and regions where ciguatera exists and updating guidance to industry 

accordingly. Such guidance is used to develop controls to prevent these toxins from entering the Nation’s 

food supply. FDA has also implemented programs that strengthen partnerships in the public and private 

sector for identifying sporadically-occurring, novel, and emerging toxins, as well as vulnerable seafood 

products. For example, methods have been developed and validated recently for detecting microcystins 

Mitigating and controlling the impacts of HAB 

toxins on human health

An important component of controlling and mitigating 

HABs is the ability to limit or extract toxins from drinking 

water and food sources. EPA’s Office of Research and 

Development is exploring the use of an emerging “green” 

technology for removing microcystins from drinking water.

The majority of drinking water treatment studies have 

focused on removing microcystins; few studies exist with 

other toxins, mixtures of toxins, and mixtures of 

cyanobacteria. Marine biotoxins increasingly will be a 

concern in areas where seawater is desalinated as a source 

of drinking water (Appendix 3).
24

in blue-green algal supplements, thereby providing tools for regulatory enforcement of safe, commercially 

available cyanobacteria-derived dietary supplements. Similarly, researchers supported by the NIEHS 

detected the cyanobacterial toxin beta-methylamine alanine (BMAA) in certain aquatic animals like crabs 

and shrimp that are consumed by humans. BMAA is a toxin linked to neurodegenerative diseases in 

humans, such as amyotrophic lateral sclerosis (more commonly known as ALS, or Lou Gehrig’s disease), 

Alzheimer's disease, and Parkinson’s disease.

5.3.1. Integrated Exposure Assessment

Integrated exposure assessments examine how the environment and pollutants affect the health of 

certain targets, such as human health (Behar, 1979). These assessments vary exposures from source to 

dose, over time and space, to multiple stressors, and from the molecular to ecosystem level in order to 

learn more about exposure effects in different settings. Such assessments aid with forecasting, 

preventing, and mitigating exposure that leads to adverse human-health or ecological outcomes by 

helping scientists create early warning systems and predictions. This helps to provide accurate information 

to resource managers, health departments, tourism operators, and the public regarding the potential for 

HAB-related illness and to prepare for controlling the HAB. This also helps groups prepare for potential 

economic impacts by giving them advanced time to plan budgets. Partnerships among NSF, the National 

Aeronautics and Space Administration (NASA), CDC, NOAA, EPA, and USGS, have resulted in various 

programs to assist managers in their immediate response to HAB events (Jewett et al., 2007; National 

Research Council, 2012). Basic and applied research and management strategies for HABs through these 

partnerships have advanced surveillance and predictive systems that “describe, reconstruct and forecast 

real world exposures more accurately and efficiently” (National Research Council, 2012). Integrating the 

scientific constructs of this effort brings existing strengths of HABHRCA-mandated science to scientific 

foundations that are now linking human and ecosystem health.

5.3.2. Drinking-Water Treatment 

Removing toxins from drinking water is essential to protecting public health. Standard treatment 

procedures in drinking-water treatment facilities can remove or inactivate some algal toxins, but 

additional treatment technologies often are necessary, as standard processes may not be able to remove

all algal toxins, especially from water sourced in the midst of a bloom (EPA, 2015b). Experts suggest that 

utilities and treatment facilities should develop individualized treatment plans for purifying drinking 

water, as toxin removal is dependent on toxin type and whether the toxin is dissolved in water or inside 

cyanobacterial cells (Westrick, 2008). 

Cyanobacteria and their toxins have been found in drinking-water systems in the United States, but there 

have not been Federal guidelines, standards, or regulations concerning the management of HAB toxins 

until recently. In June 2015, EPA published Drinking Water Health Advisories for the cyanotoxins 

microcystins and cylindrospermopsin to assist Federal, state, and local officials, as well as managers of 

public or community water systems, in protecting public health. The advisories include information 

regarding available treatment techniques and analytical methods for these particular cyanotoxins.

Furthermore, the Safe Drinking Water Act, as amended in 1996, requires the EPA to publish, every 5 years,

a list of unregulated contaminants that are not subject to any proposed or promulgated national primary 

drinking-water regulations, are known or anticipated to occur in public water systems, and may require 

regulation. This list is known as the Contaminant Candidate List (CCL). The EPA’s Office of Water included 

cyanobacteria and cyanotoxins on the first and second CCL (CCL 1, 1998; CCL 2, 2005). EPA also included 

on CCL 3 (CCL3, 2009) and the proposed CCL 4 (CCL4, 2015) anatoxin-a, cylindrospermopsin, and 

microcystin-LR for consideration.

Recent events, such as the massive algal bloom that developed on the Ohio River in early fall of 2015, 

have demonstrated the challenge that treatment facilities face in providing safe drinking water when 
25

encountering extreme HAB events. Over the last 2 years, the impact of HAB-related microcystins on 

several drinking-water-treatment facilities supplied by source water originating from Lake Erie were 

measured by EPA’s Office of Research and Development. Results showed that certain treatment 

techniques can break intact cyanobacterial cells, thereby releasing toxins into drinking water during the 

treatment process. More positively, results also showed that, if operated properly, conventional water 

treatments designed to reduce turbidity effectively reduce intact algal cells. 

While EPA regulates drinking water (i.e., tap water), FDA is responsible for regulating bottled drinking 

water. There are no specific regulations on cyanobacteria or their toxins in bottled water; FDA, however,

requires bottled-water producers to process, bottle, and hold bottled water under sanitary conditions; 

protect water sources from bacteria, chemicals, and other contaminants; use quality-control processes to 

ensure the bacteriological and chemical safety of water; and test source water and products to ensure 

that they are free of contaminants.

5.3.3. Toxin Detection Methods

HAB research, management, and impact 

mitigation depend on accurate and timely 

detection of harmful HAB toxins. Robust, 

quantitative methods for identifying and 

measuring toxins are critical to assuring the 

safety of seafood, drinking water, and 

recreational areas, as well as to supporting

clinical testing and confirming wildlife and 

domestic-animal poisonings. The complexity 

of algal toxins increases with the occurrence 

of multiple classes of HAB toxins and a 

diversity of active metabolites in ecosystems.

Furthermore, algal species toxicity can vary 

from undetectable to high levels depending 

on strain composition and physiological 

status. This complexity makes it difficult to 

fully characterize the nature and extent of

HAB impacts, and to develop effective and 

targeted methods to ensure the safety of 

food, water supplies, and recreational areas.

A variety of analytical methods are available 

for characterizing HAB toxins, some of which 

are designed to identify multiple toxin classes 

and other factors in a single sample.

Identifying the species responsible for a given 

HAB can be helpful in narrowing the search 

for the possible toxin(s) that the HAB could be producing. Collaborations and common quality assurance

and quality control protocols in lab and field work and strategy across Federal agencies and external 

organizations are essential in developing viable, rapid, and cost-effective toxin-detection methods. 

Federal and state collaborations lead to re-opening of 

one of world’s largest shellfish beds

Georges Bank, one of the largest clam beds in the world, was 

closed indefinitely to the harvest of shellfish in 1990 due to 

the risk of PSP toxins negatively impacting the shellfish 

industry. The situation became worse when an additional 

15,000 square miles of Federal waters were closed in 2005 

due to the presence of toxins. At this time, the clam industry 

reached out to FDA, NOAA, the Commonwealth of 

Massachusetts, academic institutions, and toxin test-kit 

manufacturers to seek a solution that would permit access to 

valuable shellfish resources. The resulting outcomes included 

the development of a test kit that could be used at sea by 

fishermen to determine when and where clams were safe to 

harvest, and a second test of the harvested shellfish 

performed by a laboratory. The onboard testing serves as an 

economic protection for the fishermen, while the second test 

is conducted by a National Shellfish Sanitation Programapproved laboratory to provide confirmation that the 

product harvested is safe for consumption. This collaborative 

effort resulted in the reopening of a large portion of Georges 

Bank to the harvest of surf clams and ocean quahogs in 2013, 

allowing the harvesting of billions of dollars’ worth of clams, 

with control strategies implemented to ensure seafood 

safety.
26

5.4. Monitoring 

Monitoring reduces risk,

mitigates impacts, and 

provides accurate 

information and predictive 

data for making management 

decisionsrelated to HABs and 

hypoxia. Monitoring data 

support multiple goals, from 

tracking the sources of 

pollutants, to regulatory 

action, to predictive 

modeling and forecasting.

Long-term nutrient 

monitoring is performed by 

numerous Federal and state 

agencies to track nutrient 

amounts and trends in 

discharge. Federal programs 

such as those carried out 

through USDA, EPA, and 

USGS focus monitoring 

programs on edge-of-field

areas, as well as streams and 

rivers, in order to determine 

nutrient source, transport, 

and ultimate fate, which in 

turn enables program 

managers to track progress 

towards achieving the 

nutrient-reduction goals 

needed to lessen hypoxia.

Routine monitoring 

programs for algal blooms 

and for the presence of HABderived toxins in shellfish 

were established under the 

National Shellfish Sanitation 

Program and conducted by 

many states, with as-needed 

assistance from the FDA.

Additional Federal programs and activities support the development of regional HAB- and hypoxiamonitoring programs, further assisting states. For instance, the EPA, states, tribes, and other partners are 

conducting a series of surveys of the Nation’s aquatic resources. Often referred to as “probability-based 

surveys,” these studies provide nationally consistent and scientifically defensible assessments of our 

Nation’s waters by water-body type (e.g., rivers and streams, lakes, wetlands, or coastal waters), and can 

be used to track changes in condition over time. Each survey uses standardized field and lab methods and 

is designed to yield unbiased estimates of the condition of the whole water body being studied at a 

Event-Response Programs

Event-response programs provide an early action to assist managers 

in their immediate response to HAB events in order to protect human 

and environmental health. Several Federal agencies share eventresponse capabilities.

• The National Park Service (NPS) is developing a website for use 

by national parks on how to respond to HAB and hypoxia 

events. This website will be used by all park natural-resource 

managers to report events in a park or area near a park.

Additionally, the agency is developing protocols for all parks 

for reporting any effects on wildlife, including but not limited 

to marine and terrestrial mammals, fish, birds, and shellfish.

The NPS is also developing an event database to track the HAB 

and hypoxia events that occur in national parks

• NOAA’s Marine Mammal Health and Stranding Response 

Program and the Working Group on Unusual Marine Mammal 

Mortality Events (NOAA National Marine Fisheries Service; 

U.S. Fish and Wildlife Service; Marine Mammal Commission, 

and EPA) investigate unusual mortality events.

• The USGS National Wildlife Health Center provides sample 

handling and project coordination for investigating wildlife 

disease or mortality events. 

• FDA assists states with sample collection and analysis when 

marine biotoxins are suspected in state waters, and is the 

primary responder to blooms in Federal waters. 

• The HABHRCA-mandated NOAA HAB Event Response Program 

provides funding for state managers and researchers 

investigating HAB events.

• The NOAA Analytical Response Team provides a formal 

framework through which coastal managers may request 

immediate coordinated assistance during HABs with species 

identification and toxin analysis.

• CDC has funded up to 10 states to develop programs to 

respond to HAB-related public health issues.
27

national scale and across broad, ecologically similar regions. Likewise, the survey can be used to help 

managers adapt how they manage resources in the short- and long-terms. This helps to reduce risk and 

helps to mitigate impacts, should any occur. 

Phytoplankton monitoring is increasingly being used by state agencies to provide warnings and 

precautionary closures of harvest areas before shellfish become toxic. More specifically, in 2010, 

Wisconsin used modeling data to establish numeric water-quality standards for phosphorus in rivers, 

streams, lakes, reservoirs, and state portions of the Great Lakes (Mississippi River/Gulf of Mexico 

Watershed Nutrient Task Force 2015 Report to Congress). Likewise, new remote-sensing algorithms 

developed by NIEHS-supported scientists provide improved prediction, detection, and mapping of Florida 

red-tide events.

Responsibility for monitoring dissolved oxygen in most coastal, freshwater, and Great Lakes bodies of 

water lies with states or with Federal-state partnerships that utilize state monitoring programs to track 

water quality. For many of these areas where hypoxia occurs, fairly rigorous methods have been 

implemented for measuring dissolved oxygen and conveying this information to scientists and the public.

The two largest hypoxic zones in the United States, located at the mouth of the Mississippi River and on 

the Oregon continental shelf, however, occur beyond the limits of state waters and, thus, rely on Federal 

support for monitoring. Monitoring informs coastal managers about water-quality conditions in the 

ecosystems they oversee, and it helps support the development and verification of ecosystem simulation 

models used to guide management decisions (CENR, 2010).

Nutrient loads delivered to a water body are calculated from nutrient concentrations and freshwater 

inflow. Nutrient concentrations in the water are generally monitored on monthly and on long-term bases, 

showing how nutrient concentrations vary over time. This helps managers and policymakers target 

specific times of year for developing effective mitigation strategies. This sampling schedule, however, can 

miss important events such as periods of high rainfall, when increased runoff brings more nutrients and 

can cause wastewater treatment plants to overflow, delivering greater-than-normal loads of nutrients to 

the water body. This sampling methodology can also miss pollution that comes directly from the air or 

groundwater. Hence, to better understand the small-scale changes in nutrient load and concentrations 

that can contribute to hypoxia, researchers have been investing in continuous nutrient measurement. For 

example, the USGS has 104 sensors nationwide (with over 40 sensors in the Mississippi River Basin alone)

that measure nutrients on an hourly basis to more accurately determine nutrient loads to coastal bodies 

of water. This sensor network is operated through partnerships with other Federal and state agencies.

5.4.1. Observing Systems

Observing systems provide diverse streams of physical, chemical, and biological data for predicting HAB 

and hypoxia events in aquatic ecosystems in our Nation’s oceans, coasts, freshwater bodies, and Great 

Lakes. Deployment of multiple observation platforms and sensors is required for monitoring the spatial 

and temporal resolution of phytoplankton that cause HABs and hypoxia. Satellites, moored ocean 

platforms or buoys, autonomous vehicles, and human observer networks provide data that can be

assimilated into numerical models to develop forecasts and seasonal predictions of HABs and hypoxia

events.

Having these technologies readily available helps communities prepare for HABs and hypoxia events

and mitigate the effects of these phenomena on human and animal health, as well as on the economy. 

For instance, some species of Pseudo-nitzschia create a potent neurotoxin, domoic acid, which 

accumulates in filter-feeding fish and shellfish. When ingested, usually through seafood consumption, 

domoic acid can cause ASP, a severe and sometimes fatal illness. There are sensors for Pseudonitzschia and domoic acid that can be deployed on Environmental Sample Processors (ESPs) to detect the 

species and toxin as a bloom develops. Most recently, this was useful during an unprecedented, wide-
28

spread Pseudo-nitzschia bloom along the West Coast of the United States, providing communities with 

early warnings about potential human- and animal-health risks, and allowing managers to close 

proactively fisheries to harvest.

5.4.1.1. Eyes in the Sky

The physical and visual properties of water can reveal important insights about the biology of a water 

mass, as well as its potential to support HAB development and movement. A variety of airborne (aircraft) 

and spaceborne (satellite) commercial and government platforms are currently available for conducting 

remote water-quality evaluations (Reif, 2011). Airborne sensors measure the light and heat emitted from 

upwelling regions over large geographical areas in narrow bands. They provide data from visible and nearinfrared wavelengths. Spaceborne sensors allow for consistent and frequent measurement of the light 

and heat from the Earth over moderate spatial resolution on regional and global geographic scales.

Researchers have used data generated by such sensors effectively to detect phytoplankton-bloom activity 

and to inform models forecasting the development and movement of blooms on regional scales. The EPA 

is developing the Cyanobacteria Assessment Network (CyAN) mobile application using satellite-derived 

water-quality information—such as cyanobacteria cell-count concentrations for a local lake—to help 

water-quality managers make assessments (Wynn et al., 2013; Lunetta et al., 2015).

5.4.1.2. Eyes in the Water

There is a critical need for real-time, in-water observations of physicochemical properties (including 

dissolved oxygen), as well as of HAB species and toxins, to provide data streams for assimilation by 

predictive models. In-water sensors can take continuous measurements, supporting detection of physical 

and chemical indicators of HABs and hypoxia events. In-water observation systems—including moored 

observation platforms and autonomous underwater vehicles, or “gliders”—are well-developed and fully 

integrated into observing-system infrastructure in many areas. For example, in the Great Lakes, real-time 

information collected by a pilot observing-system buoy located in Lake Erie near Cleveland, Ohio, is 

provided to local drinking-water-processing managers. This information gives hourly updates of 

decreasing dissolved oxygen, internal wave status, and temperature profiles, which are used to determine 

the depth of the temperature gradient (thermocline) and dissolved oxygen levels. The data may warn of 

potential hypoxic events from July through October and give managers time to prepare alternate 

processing methods.

Although timely reporting of conditions that may lead to HAB or hypoxia events is indeed useful, realtime, autonomous measurements of algal cell and toxin concentrations and of dissolved oxygen can 

provide the level of detail required for accurate early warnings as well as for the current status of an 

ongoing HAB or hypoxia event. Technologies with such capabilities are now commercially available and 

are being deployed as experimental components of several observing networks to detect HAB or hypoxia 

development or assess the toxicity of an event. Over the next 5-10 years, maturation of observationsystem technologies will facilitate their transition to operational status and full integration within regional 

observing systems.

5.4.1.3. Eyes on the Coasts

Citizen engagement plays an important role in HAB and hypoxia surveillance, and therefore in predicting 

and mitigating HABs and hypoxia events. A number of relevant citizen-science programs are run across 

the country. NOAA’s PMN program links volunteers who monitor for marine phytoplankton and HABs with 

professional scientists, effectively building a more-informed public while expanding the reach and 

resolution of HAB monitoring. Over 200 PMN volunteers sample more than 140 sites in 17 states and the 

U.S. Virgin Islands. Volunteers are trained by NOAA staff on sampling techniques and identification 
29

methods for marine and freshwater phytoplankton. Since the program began in 2001, volunteers have 

reported more than 120 algal blooms and 7 toxic events.

NOAA has worked with other Federal agencies to improve the PMN program. The PMN program prior to 

2010 focused on marine phytoplankton species; beginning that year, however, CDC and NOAA agreed to 

collaborate on a study to examine if PMN methods could be applied to monitoring HABs in freshwater 

lakes. The pilot study included 12 lakes in Minnesota and Wisconsin, with 34 sample locations identified 

by CDC. Additionally, CDC provided funding to adapt the existing marine methodology, and to provide

training and equipment for 39 volunteers. The study targeted four freshwater cyanobacterial HABs and 

two nontoxic bloom species, and researchers analyzed 275 samples between June and October 2010. Of 

note, 97 percent of the samples were found positive for at least one target species. Moreover, all 

Wisconsin lakes contained presence of the toxic species Microcystis during the sampling season. Three 

major blooms were confirmed to be composed of toxic species, and several "green water" blooms that 

were presumed to be toxic were composed of nontoxic species. This pilot study demonstrated the 

effectiveness of PMN method for volunteer monitoring of toxic versus nontoxic freshwater HABs. It also

provided the foundation for the NOAA and EPA to respond quickly to establish freshwater PMN sites in 

Lake Erie in 2015 and to expand to Lakes Superior, Michigan, Huron, and Grand Lake St. Mary in 2016. 

NOAA entered into an Interagency Agreement with EPA to expand the PMN to freshwater HABs in the 

Great Lakes region beginning in 2015 (Appendix 3). Other examples of long-term monitoring programs 

include the Olympic Regional HAB (ORHAB) and SoundToxins partnerships, which provide early warnings 

of HABs on the outer Washington coast and Puget Sound, respectively.

5.4.2. Models and Forecasts

New and expanded observing capabilities have grown the potential for early detection and 

characterization of HABs and hypoxia events. Yet given the considerable temporal and spatial scale of 

HABs and hypoxia events, direct observations alone cannot provide sufficient warning and information 

about all HABs and hypoxia events in all areas in which such events may occur. Accordingly, a range of 

models exist to complement the early warnings and forecasts derived from direct observations 

(McGillicuddy, 2010).

For instance, models have been used to study the sources of nutrient pollution—a key contributing factor 

to both HABs and hypoxia events. Models such as the USGS’ SPAtially Referenced Regressions on 

Watershed (SPARROW), or USDA’s Agricultural Policy Environmental Extender (APEX) and Soil and Water 

Assessment Tool (SWAT) (used in CEAP), provide consistent approaches to estimating nutrient sources in

coastal areas. Long-term data on nutrient enrichment has been used in other SPARROW models, which 

examine nutrient sources for freshwater streams, lakes, and coastal areas, and in new methods for 

detecting trends in nutrient loads.
30

These models indicate (Figure 5.1) that agricultural input (i.e., manure, fertilizer, and legume crops) is the 

largest nitrogen source for the conterminous United States (50 percent of the total), atmospheric 

deposition contributes 27 percent, and urban sources contribute about 22 percent (7 percent from urban 

areas and 15 percent from wastewater-treatment plants). Anthropogenic phosphorus inputs are 

proportionately lower because of larger contributions from background sources, including weathering of 

phosphorus-rich soils and bedrock, as well as erosion of phosphorus-rich stream sediments previously 

deposited from upstream sources. The relative contributions of sources vary across and within

watersheds. For example, while agricultural, atmospheric, and urban sources are the predominant 

nitrogen sources in the North/Mid-Atlantic, Great Lakes, and Pacific Northwest, respectively,

approximately 50 percent of the annual nitrate load into the Chesapeake Bay enters the watershed 

through streams via groundwater (Sanford, 2013). 

Numerical models provide the foundation of NOAA’s HAB forecasting system developed for Karenia brevis

blooms in the Gulf of Mexico (Stumpf et al., 2009). HAB forecasts are made twice weekly during bloom 

events, using a combination of satellite-derived image products, wind predictions, and a rule-based model 

derived from previous observations and research. Blooms are detected and defined using ocean color 

satellite images. Bloom transport is then predicted using hydrographic modeling with particle-tracking 

techniques. 

Figure 5.1. Source shares of nitrogen load delivered to the coastline of the conterminous United States, by region. 

Maps of nitrogen and phosphorus yields, loads, and watershed rankings with nutrient source information for a 

state or large river basin can be accessed using the USGS SPARROW model. SPARROW results for key estuaries 

have also been tabulated, and the SPARROW Decision Support System can simulate nutrient reduction scenarios 

for selected watersheds.
31

Seasonal forecasts for the Gulf of 

Maine and the Chesapeake Bay show 

the size, movement, and potential 

severity of specific types of HABs and 

hypoxia events in those regions (Allen 

et al., 2015). The models are based on 

a number of factors, including water 

motion driven by winds, tides, 

stratification, river runoff, and 

upwelling. They also take into account 

temperature, salinity, sunlight, and 

nutrients. Seasonal forecasts in the 

Chesapeake Bay specifically draw on 

the relationship between reducing 

nutrient loads and a resulting decrease 

in late-summer hypoxia. In the longterm, analysis of 60 years of monitoring 

data showed that reducing nutrient 

runoff into the Chesapeake Bay has 

reduced hypoxia in the late summer, 

but large-scale climatic forces are 

leading to early-summer hypoxia 

formation. Despite the influence of 

climatic factors on hypoxia, nutrient 

management is a key mitigation 

strategy for improving the water 

quality of the Chesapeake Bay (Kemp et 

al., 2005). In the Chesapeake, the Gulf of Maine, and other locations, improved information and forecasts 

of same-season variability allow farmers and other agricultural producers to better manage fertilization, 

tillage, drainage-water management, and other systems. This information is also useful for water 

managers and other industries to use for advance planning.

5.5. Public Advisories

Providing advance notice of the possibility of HABs or hypoxic conditions is a critical step in addressing 

human-health concerns and helping to mitigate the impacts of these events. Reaching out to communities 

and making readily accessible and available information about HABs or hypoxia events enhances 

consumers’ awareness of potential hazards of these phenomena and enables managers to make sciencebased decisions, thereby helping to protect the health of communities. Advisories also allow tourism 

operators and other business owners who may be affected by HABs and hypoxia to prepare accordingly.

The expansion of NOAA’s HAB- and hypoxia-forecasting 

systems—including systems that provide advanced 

ecological forecasts, early-warning bulletins, and other 

early-warning products—has had a significant impact upon 

the ability of communities and regions to prepare for these 

events, and represents one of the singular 

accomplishments since the last authorization of HABHRCA. 

A list of these forecasts follows:

HAB Forecasts:

● West Florida Shelf (operational)

● Texas (operational)

● Lake Erie (in transition to operations – 2016-2017)

● Gulf of Maine (demonstrational/experimental)

● Puget Sound (demonstrational)

● Washington Coast (demonstrational)

● California (demonstrational)

● Chesapeake Bay (future)

Hypoxia Forecasts:

● Gulf of Mexico (demonstrational/experimental)

● Chesapeake Bay (demonstrational/experimental)

● Puget Sound (demonstrational/experimental)

● Green Bay (demonstrational/experimental)

● Narragansett Bay (demonstrational/experimental)
32

6. Challenges in HAB and Hypoxia Management

There are many gaps in the research and management communities’ knowledge of HABs and hypoxia

events. The complex causes and effects of these events understandably present many challenges to 

researchers, managers, and decision-makers in HAB and hypoxia prevention, control, and mitigation. 

The ability to predict the response of HABs and hypoxia to changes in nutrient loading and other drivers, 

such as climate, is difficult but critical. Land-use change, changes in precipitation patterns, and altered 

hydrology collectively have led to increases in stream discharge, as well as baseflow (Zhang and Schilling,

2006; Schottler et al., 2014; Scavia et al., 2014). The management of nonpoint nutrient pollution, in 

particular, requires a better understanding of nutrient discharge to surface water and groundwater.

Understanding the delivery modes of nutrients to the coasts would allow policymakers to better 

characterize the lag time between nutrient reduction on land and improvements in the quality of in 

surfacewater and groundwater. Similarly, improving understanding of the impact of legacy phosphorous 

and sediment within river systems or lakes is significant for predicting and addressing HABs and hypoxia

events. Researchers need to learn more about how the cycling of legacy phosphorous or sediment is 

affected by reductions of new sediment or phosphorous entering the system, and to establish the causes 

of annual nitrate-level fluctuations. Scientists also need better information on contributing nutrient 

sources such as fertilizers, urban inputs, and wastewater to develop nutrient control and monitoring 

strategies.

Predicting species composition of algal bloomsis challenging, as is determining the circumstances in which 

a potentially toxic bloom will produce toxins. Improving knowledge of the response of HABs and hypoxia 

to nutrient-reduction strategies and changes in weather patterns and climate will help to develop decision 

support tools that are grounded in science.

6.1. Environmental, Economic, and Social Challenges

The environmental, economic, and social impacts of HABs and hypoxia in marine and freshwater regions 

are incompletely understood. Research is needed to identify and quantify how HABs and hypoxia affect 

ecosystems, such as through habitat loss and food-web disruption, so that cost-effective and scientificallysound management strategies—including strategies for reducing nutrient inputs—can be developed and 

implemented to achieve healthy water quality in rivers and streams, lakes and reservoirs, and estuaries 

and near-coastal marine waters. There is also limited research examining the short- and long-term effects 

of HABs and hypoxia on communities. The lack of clarity on the impact of HABs and hypoxia represents 

the largest source of scientific uncertainty for policy development in most systems. This is a compelling 

driver for action, as the lack of information of costs and benefits of various management options presents 

a significant stumbling block to implementing mitigation plans in many regions. 

6.2. Monitoring Challenges

The challenges of monitoring include sustaining monitoring programs, ensuring consistency of monitoring 

methods, implementing rigorous benchmarks of quality assurance and quality control, and synthesizing 

and making available monitoring data.

The successful deployment of nutrient sensors for continuous, real-time monitoring depends on ongoing 

evaluations of sensors and technologies that communicate data, development of nutrient-monitoring 

standards and protocols, improvements in tools for data-quality assurance and data visualization, and 

personnel training.

Toxin monitoring could be advanced by having sensors that can directly detect toxins in situ and in real 

time. This would help defend against human or animal exposures or effects in marine, fresh, and 
33

recreational waters, and at drinking-water sources. Even though there has been some success in detecting 

toxins with in situ sensors, only a few toxins or derivatives are well understood and categorized. Another 

toxin-monitoring challenge relates to knowledge of the varieties of cyanotoxins and derivatives to 

understand which are most toxic. Developing new or improved sensors that are able to differentiate 

different types of HABs, and even toxic vs. non-toxic groups of HABs, would be beneficial.

Challenges in integrating data on HABs and hypoxia are due to the variety of stakeholders collecting and 

using this information. While increased collaboration helps to develop new methods of data collection 

and analysis, it also increases margins for error and slows down systems due to additional layers of process 

and review. 

6.3. Research and Modeling Challenges

Researchers are trying to address the conditions that contribute to, cause, or end HABs, HAB toxins, and 

hypoxia with improved models and more collaborative, interdisciplinary research. Given the complexities 

of the number of HAB species, and the evolution of how drivers interact to lead to HABs and hypoxia, 

many challenges remain. 

Specific studies in functional dynamics at the microbial levels are needed because algal cell processes may 

hold the key to understanding the production of HAB toxins. Conditions in an ecosystem can affect the 

ability of a cell to reproduce or to exist long enough to form a bloom. Additionally, certain species of algae 

feed upon others, or simply are stronger competitors for resources, allowing these species to proliferate 

and form blooms (Marinho et al., 2013; Chakraborty and Feudel, 2014). Scientists at this point are unclear 

as to how exactly the specific dynamics function at microbial levels, however.

A major challenge in modeling HABs and hypoxia is the complex nature of how nutrients and other factors 

influence HAB and hypoxia development. While the processes that produce these events are understood 

generally, local factors strongly influence the severity and other characteristics of HABs and hypoxia 

events. Wind, rain, water-column stability, buoyancy changes in cells, underwater irradiance, and lake 

morphology all impact the ability of models to predict blooms. Furthermore, making predictions is further 

compounded as these factors must be modeled in conjunction with nutrient levels and the varying, 

complex conditions of a given body of water.

Factors that affect local nutrient conditions include nutrient inputs from watershed, atmospheric, and 

other sources; nutrient processing and recycling on local and broader scales, once these nutrients enter a 

water body; and the relationship between nutrients and algal productivity. Improved water quality and 

ecosystem models are needed to better assess and predict effects of nutrient management on 

downstream water quality, and the impacts of hypoxia on fish populations and food-web dynamics, in 

order to refine management strategies for protecting coastal economies and aquatic resources.

Models can estimate external nutrient inputs and simulate nutrient processing and algal production, but

every model relies on monitoring data, which can be variable in quality. Every model undergoes different 

types and levels of quality control. Additionally, few models are available that link HABs and hypoxia

events with impacts on social well-being, economics, and human health, and therefore there is little

actionable information for use in developing comprehensive management plans.

Models must take into account at least three components: nutrient sources from the land, atmosphere 

and ocean; how nutrients are processed on local- and estuary-wide scales once they enter a water body; 

and how the nutrients influence the growth of algae species. Presently, there are models that estimate 

the loads of nutrients that enter a water body from land, air, and sea. Likewise, there are models that 

simulate the way that nutrients move around and through a water body once they enter it, and still others 

that account for algal growth and changes in nutrient concentrations as the algae use the nutrients. Many 

of these models are highly complex and do a good job of representing nutrient movement from land to 
34

water, and, separately, nutrient movement in the water. There are limited models or modeling systems 

that integrate the two components of nutrient movement and provide information on the associated

impacts on social well-being and economic and human health that can inform comprehensive 

management plans. Overall, expansion of river, stream, and watershed monitoring, coupled with 

increased modeling information, can advance understanding of nutrient sources, transport, and ultimate 

destination, thereby enabling better tracking of progress towards achieving nutrient-reduction goals.

6.4. Human Health Impacts Challenges

To reduce human-health impacts caused by 

exposure to HABs, scientists must understand the 

causes of HABs and the level of awareness of 

associated human-health risks. Specifically, 

researchers must study how different toxin 

concentrations and exposure scenarios—

including exposure type (inhalation, dermal, or 

ingestion) and duration (acute or chronic)—

affect humans, as well as the concentrations of 

different toxins needed to trigger adverse health 

effects. Identifying individuals who are at higher 

risk for experiencing adverse health events 

related to harmful algae exposure also is a 

priority.

The WHO has developed guidelines for lifetime 

drinking-water exposure to microcystin-LR, and 

for acute exposures to cyanobacterial cells in 

recreational waters. Additionally, three 

cyanotoxins (microcystin-LR, 

cylindrospermopsin, and anatoxin-a) have been proposed for EPA’s CCL for evaluating public health risks 

in drinking-water systems. In June 2015, the EPA released 10-day Health Advisories (HAs) for two 

cyanobacterial toxins: microcystins and cylindrospermopsin. The advisories describe concentrations of the 

two algal toxins in drinking water at or below which adverse health effects are not anticipated to occur 

over a 10-day exposure period. The EPA also released a support document containing recommendations 

for managing cyanotoxins in drinking water, which includes a framework for cyanotoxin risk-management 

efforts. Some states and other countries have developed their own guidelines for certain toxins (Graham 

et al., 2009; Chorus, 2012). The basis for these guidelines and recommendations rests primarily upon 

knowledge of acute and subacute toxicity of cyanotoxins; there are still large knowledge gaps regarding

the effect of chronic exposure to cyanotoxins on human and animal health.

Human and animal exposure to HABs can involve multiple toxins (either simultaneously or sequentially), 

making it difficult to track and test for toxin source. Exposure to multiple toxins can result in both 

synergistic and additive harmful effects: one toxin might target the liver, which provides detoxification for 

a second toxin that targets a different organ system, or two toxins might target the same organ system 

by different mechanisms. Studies on the effects of multiple toxins require considerable resources and 

manpower, but they can be important, given the possibility of such effects.

Impacts of HABs on wildlife in managed and natural environments present a particular challenge that 

needs to be addressed. While drinking water intended for human consumption can be treated to remove 

toxins, animals consume and come into contact with untreated aquatic waters and therefore are at higher 

risk of being directly exposed to HABs. Furthermore, HAB-related animal illnesses may be underreported 

Image 6.1. Fishermen testing for paralytic shellfish 

poisoning toxins onboard a fishing vessel as a part of the 

Onboard Screening Dockside Testing biotoxin control 

strategy (Photo courtesy of Stacey DeGrasse, FDA)
35

(Backer et al., 2013) because clear and easy-to-use reporting tools and communication mechanisms are 

not readily available to pet owners, veterinarians, wildlife and fisheries personnel, medical and publichealth officials, and others. Addressing this issue would also lead to additional human benefits. Hence 

animal deaths and illnesses resulting from HABs or hypoxia events can serve as sentinels of potential

human-health risk and, if such incidents are reported quickly, can trigger appropriate responsive action 

that mitigates risk (van der Schalie et al., 1999).
36

7. Research Plan and Action Strategy: Recommendations

Progress to this point has demonstrated that science-based decision-making can effectively help prevent 

and mitigate the effects of HABs and hypoxia events. Keeping up with the evolution of HAB and hypoxia 

events and the continual discovery of new HAB species, however, is challenging. While Federal agencies 

have successfully implemented and planned many programs related to HABs and hypoxia, there are many 

ongoing gaps in policies, programs, and science that require attention. The IWG-HABHRCA recommends 

the following Federal research plan and action strategy. An implementation plan is pending. 

1. Adding to and Improving Scientific Understanding

a. Develop certified reference materials (CRMs) and other standardized and validated detection 

and analysis methods for HAB toxins.

HABHRCA calls for increasing the availability of analytical facilities and reference materials, 

and improved ability to predict the onset of toxicity. The biggest challenges to analyzing HAB 

toxins include the limited availability of CRMs and standardized and validated analysis 

methods,3 all of which are essential to ensuring consistency and comparability of results 

between laboratories and other testing environments. CRMs are lacking for many of the 

classes of toxins that impact American waters, as well as those of international origin that 

may enter the United States’ food supply through seafood. 

While progress has been made herein, the scope of the remaining need is greater than any 

one agency. The IWG-HABHRCA recommends establishing an interagency team to examine 

current capabilities, and to establish a strategy for developing intra- and interagency methods 

and approaches for developing and sustaining CRM availability. An outcome of this IWG could 

include establishing a network of several reference laboratories. 

Additionally, there is a need for commonly available, affordable methods for toxin analyses—

quality-assured with CRMs—that can be implemented by a variety of user groups, and 

validated by analytical methods and inter-laboratory trials. These will ensure comparable 

results from the earliest to the final tiers of testing, thereby helping to improve the ability of 

all user groups to prevent, control, and mitigate HABs.

b. Conduct studies on toxins in food and on toxin mixtures.

While reported algal toxin-related human illnesses are often associated with the consumption 

of seafood, based on dietary history and symptoms, confirmation of foodborne illness 

remains a challenge. For instance, ciguatera fish poisoning is the most common HAB toxinrelated seafood poisoning, yet a confirmed diagnosis is difficult due to a lack of accurate

clinical methods for detecting ciguatoxins in biological specimens.

Likewise, human and animal exposures to HABs often involve multiple classes and metabolites 

of toxins, and there is a critical need for finding a better way to assess the relationships 

between these toxins. Although toxicological evaluations of toxin mixtures require 

considerable resources and manpower, such evaluations are essential given the real potential

of additive or synergistic effects from multiple toxins. This precautionary approach ultimately 

 

3 CRMs, for the purpose of this paper, are analysis frameworks for identifying types of toxins and their 

concentrations. CRMs also establish standards for the types and calibrations of instruments that are used for 

performing these analyses.
37

will help managers and the government to issue advisories and make accurate policy decisions 

in the future. 

c. Develop more-effective HAB suppression and control methods that have minimal 

environmental effects and lower cost. 

Potential control techniques are needed to investigate further include increasing flushing 

rates, ultrasound, electrocoagulation, new and existing coagulants, and new algicidal or 

algistatic compounds. These techniques are used to break up HABs.

d. Understand the influence of climate change, atmospheric deposition of nutrients, and other 

contributing factors on the occurrence, frequency, and severity of HABs and hypoxia. 

Potential effects of climate change include rising average water temperatures and increased 

precipitation, which can support the development of HABs and hypoxia. Other impacts of 

climate change, including ocean acidification, interact with nutrient loading and 

eutrophication in the coastal zone, which may result in additional impacts to aquatic life

(including aquaculture). The exact nature of these interactions and their impacts generally are 

not well understood and should be the subject of further research.

Scientists also need a better understanding of how other factors affect HABs and hypoxia.

Particularly, there are knowledge gaps related to the effects of point and nonpoint sources of 

nutrients, such as atmospheric deposition of nitrogen or sediment and nutrient runoff, may 

lead to HABs and hypoxia events.

e. Develop case definitions for the spectrum of HAB-related illnesses and produce clinical 

therapeutic guidance for the spectrum of illnesses associated with exposure to HAB cells and 

toxins.

2. Monitoring

a. Strengthen long-term HAB and hypoxia monitoring activities. 

In many cases, comprehensive monitoring programs are needed to provide enough coverage 

of both watershed and coastal waters to support scenario-based models used to determine 

progress of management actions and inform management and mitigation strategies.

Comprehensive monitoring programs are also important for determining the effects of 

climate change on HABs and hypoxia, such as the potential impacts of increased ocean 

acidification on cellular toxicity. More comprehensive and coordinated monitoring programs 

are needed to better understand the relative contributions of different nutrient sources to 

HABs and hypoxia, which nutrient forms are most problematic, and the relationship of 

nutrients to the development of HABs or hypoxia and HAB toxicity. Expanded monitoring can 

help advance understanding of the relationships of nutrients with other factors that 

exacerbate HABs and hypoxia, such as increased water temperature.

In particular, there is a need to strengthen long-term monitoring activities conducted by 

USDA, USGS, NOAA, and EPA in the Gulf of Mexico watershed and coastal zone through 

implementation of the National Monitoring Network. In the dead zone of the northern Gulf 

of Mexico, lack of operational support has limited the execution and management capacity of 

an implementation plan for a comprehensive monitoring program designed to help scientists 

understand hypoxia causes and impacts. Furthermore, in the Great Lakes and other inland 

lakes, better monitoring is needed to help determine the relative impact of quagga mussels 

on in-lake responses to phosphorus-management strategies, and determine how sediments 

affect internal phosphorus cycling and loading and associated effects on HABs and hypoxia. A 
38

greater understanding of legacy phosphorus and sediment in Lake Erie in particular is needed

to inform response strategies to more effectively address HABs and hypoxia events.

b. Integrate new monitoring technologies into emerging U.S. and global ocean-observation 

systems. 

For a more complete understanding of HABs and hypoxia, new sensor technologies must be 

incorporated into observations systems to enable the collection of wide streams of 

environmental data that can be used to trigger early warnings and improve HAB or hypoxia 

characterization. Likewise, the development and deployment of more portable instruments 

by field observer networks will enable faster detection of algal cells and toxins to trigger early 

protective actions, and increase the spatial and temporal resolution of data on HABs or 

hypoxia events.

c. Develop a rapid-response strategy for assessing HAB exposure.

There is a need to establish a rapid sample collection and response protocol for detecting HAB 

toxins in humans and animals. Given how quickly many toxins are metabolized, protocols like 

this will strengthen diagnoses and will help to establish the best treatment methods. 

3. Prediction

a. Develop, improve, and validate HAB and hypoxia models and remote sensing.

Predictive models are critical for understanding HAB and hypoxia effects on ecosystems, and 

for enabling effective forecasting of and response to toxins in drinking and recreational 

waters. Improvement and expansion of HAB and hypoxia modeling efforts and remote 

satellite sensing can also help to improve early-warning technologies to minimize human and 

animal exposure to HAB toxins, and to assess progress of management actions and mitigation 

strategies. Researchers also need models to help elucidate the fate and effects of HAB toxins, 

as well as the long-term risks to ecosystems from exposure to HAB toxins. Furthermore, the 

ecosystem impacts of hypoxia on fisheries can differ by fish species, requiring both 

population-level and ecosystem-level modeling approaches to fully quantify ecological and

socioeconomic consequences. In addition to in situ monitoring via moored platforms and 

gliders, these efforts should include satellite and aircraft remote-sensing capabilities for HABs 

and hypoxia that can be utilized in monitoring and management programs.

b. Develop enhanced surveillance for human and animal exposure, illnesses, disease, and deaths 

resulting from HAB toxins.

This should build on existing surveillance systems, such as the HABs module in the National 

Outbreak Reporting System of CDC.

4. Emphasize Stakeholder Engagement and Socioeconomic and Understanding

a. Improve communication and coordination among health and environmental agencies so that 

reports of HAB-associated animal poisonings are used as an indicator of potential humanhealth risk. Develop science-based guidelines for cyanotoxins.
39

Researchers must develop science-based guidelines for cyanotoxins, to help managers make 

effective decisions and improve their public communications. Managers should work to 

develop communications and outreach programs to make information on HAB poisoning 

syndromes available to the medical and veterinary community in a timely manner. Wildlife 

and fisheries personnel are usually the first responders to mass wildlife deaths associated 

with HABs. Among some of these occurrences, animal deaths and illnesses may be used as 

potential sentinels of human-health risk, as the animals have higher direct exposures to HABs 

in natural waters that may be used for food provision, recreation, or as a source of drinking 

water by humans. Communication among wildlife, veterinary, medical, and public-health 

officials needs to improve to increase HAB surveillance and to protect the public health.

b. Identify susceptible populations at higher risk for HAB-associated adverse health effects.

Identify people and animals at increased risk for HAB-related adverse health effects and target 

them for interventions. To prevent illnesses, researchers must understand their cause. People 

in areas of chronic exposure may be aware of the risk of HAB toxins but lack the means 

necessary to prevent illness, therefore leaving them at higher risk of HAB-related illness.

c. Expand stakeholder engagement.

The strategies to reduce human impacts from HABs and hypoxia involve a combination of 

improving the availability of existing resources, better coordination and communications 

among stakeholders, and setting priorities for programs to facilitate technology transfer.

There is a critical need for rapid, cost-effective monitoring tools that can be used to involve a 

large group in monitoring HABs and hypoxia. Improvements in monitoring tools and data 

sharing are needed to bolster the capacity of stakeholder groups in HAB and hypoxia

prediction, detection, and response, which in turn will make it possible to implement the 

necessary management actions and focus toxin testing where it is most needed. Expanded 

stakeholder engagement is also important for educating managers, planners, decisionmakers, and the public about what monitoring data can tell them about the risks presented 

by HABs. Public service announcements about the effects of HABs and hypoxia, and how to 

avoid and prevent them, can be helpful in catalyzing increased public engagement and action.

Engaging land owners and agricultural producers within affected basins and watersheds is 

critical to increasing awareness of the issues and developing a shared strategy to inform 

decision making and more successfully HAB and hypoxia issues.

b. Evaluate socioeconomic impacts of HABs and hypoxia, and the costs of mitigation.

There are many knowledge gaps related to the socioeconomic impacts of HABs and hypoxia, 

including in inland lakes. Assessment of the socioeconomic impacts of individual HAB or 

hypoxia events is needed in order to determine which types require the greatest attention 

and resources. 

Also needed are models of the socioeconomic costs of HAB and hypoxia impacts (on food, 

drinking water, recreation, natural resources, as well as aesthetic impacts and lost ecosystem 

services), and the cost effectiveness of prevention, control, and mitigation strategies, 

including nutrient reductions, to support decision-makers and inform the prioritization of

mitigation approaches and goals. Developing these models may require recruiting resource 

economists and other social scientists to help assess HABs and hypoxia events. 

5. Policies and Synergies with Other Programs

a. Continue and expand relevant research, management, and policy collaborations.
40

Many of the research initiatives mentioned in this report have been made possible by 

collaborations among Federal agencies, as well as with other state and local entities, and with 

the public. Larger, more complete datasets need to be developed and shared between 

agencies and outside of the government, and used in developing improved forecasting and 

decision-making products. As a broader diversity of sectors are involved in these 

collaborations, people will be more educated about the changes in their environment, 

enabling the most effective HAB and hypoxia prevention, control, and mitigation effort 

possible.

b. Develop guidelines and tests for HAB toxins in drinking and recreational water, and improve 

toxin removal during water treatment. 

Continued efforts to make drinking water safer from HAB toxins should include development 

of real-time monitoring systems for toxins and cell fragments during water treatment.

Investigations of other methods for removing toxins during water treatment—including 

enhanced coagulation technology, filtration effectiveness, and disinfectant by-products—are 

similarly important. 

8. Integrated Assessment of Great Lakes HABs and Hypoxia

8.1. Introduction 

The intent of this chapter is to serve as a separate integrated assessment on HABs and hypoxia in the 

Great Lakes. HABs have occurred in all of the Great Lakes, causing detrimental effects like hypoxia or 

producing pathogens that affect wildlife and humans. Specific to the Great Lakes, some HAB species can 

harbor pathogens that include avian botulism, which kills fish and birds, and waterborne human 
41

pathogens. Most HAB events in the Great Lakes are composed of cyanobacteria (Appendix 1), and green 

algae (e.g., Cladophora) predominantly form the HABs that create algal masses.

HAB events occur in the summer months in the western basin of Lake Erie, Saginaw Bay, and Green Bay 

as well as in multiple small embayments and tributaries, such as the Sandusky and Maumee Rivers, 

Muskegon Lake, and Little Bay de Noc. Since the late 1990s, blooms have also occurred on the southern 

shore of Lake Ontario, and more recently in the waters of western Lake Superior. HAB species can be 

found in the nearshore waters of each of the Great Lakes. 

Hypoxic zones occur most frequently in the central basin of Lake Erie and in Green Bay (Burns et al., 2005; 

Hamidi et al., 2013), but also episodically in western Lake Erie and Saginaw Bay (Bridgeman et al., 2006; 

Stow and Hook, 2013). Though hypoxia occurs naturally in Lake Erie’s central basin (Delorme 1982), 

human activities, including nutrient loading, have made it worse (Scavia et al., 2014).

8.2. Causes of HABs and Hypoxia

This section of the report covers the causes, consequences, current research programs, and gaps in 

research and management with regard to prevention, control, and mitigation of HABs and hypoxia events 

in the Great Lakes. Since the 2004 HABHRCA authorization, substantial progress has been made with Great 

Lakes HABs and hypoxia events through expanded and improved policies, research, and management 

programs.

Point-source nutrient inputs to the Great Lakes were reduced to a great extent in the 1970s, which 

substantially reduced regional HABs and hypoxia events. Since the late 1990s, however, HABs and hypoxia 

events in the Great Lakes have had a resurgence, most notably in Lake Erie. Contributing factors include 

increased non-point, agricultural inputs of dissolved reactive phosphorus and both inorganic and organic 

forms of nitrogen, combined with changes in precipitation timing and intensity, which can affect nutrient 

transport and increases in stream discharge (Chaffin et al., 2013; Michalak et al., 2013; Scavia et al., 2014). 

Aging sewer systems and an associated increase in combined sewer overflows could also be a contributing 

factor, although this is less certain.

HABs in the Great Lakes likely are the result of complex interactions among multiple factors rather than 

any one specific factor (Smith et al., 2015). Phosphorus and nitrogen directly promote excessive algal 

biomass that can be associated with higher HAB toxin levels in some aquatic species (Hudnell et al., 2008; 

Davis et al., 2010; Horst et al., 2014). The presence of invasive dreissenid mussels in the Great Lakes 

appear to promote some HAB species, but the connection is not always clear (Vanderploeg, 2001; Conroy 

et al., 2005; Bridgeman and Penamon, 2010). Herbicides and pesticides that are washed into lakes during 

application or times of high precipitation can also promote Great Lakes HAB species by killing their natural 

competitors (Peterson et al., 1997; Lürling and Roessink, 2006). Hypoxia is caused when organic matter, 

including settled algal biomass, is decomposed by bacteria that consume oxygen, and it can also promote 

HABs by increasing phosphorus release from sediments (Correll, 1998).

In the Great Lakes, warm, calm water caused by seasonal temperatures and wind patterns can promote 

the separation of oxygen rich and depleted waters. Climate change may exacerbate one or many HABs 

and hypoxia events (Paerl and Huisman, 2008; Davis et al., 2009; O’Neil et al., 2012; Paerl and Otten, 2013) 

by causing even warmer air and water temperatures, and by causing changes in precipitation patterns 

that increase stream discharge and promote phosphorus and nitrogen loading into nearshore waters 

(Paerl and Paul, 2012; Michalak et al., 2013; Scavia et al., 2014).
42

8.3. Impacts of HABs and Hypoxia 

HABs and hypoxia impacts in the Great Lakes are similar to those in marine and other freshwater systems.

For more details about the effects of HABs and hypoxia in aquatic environments, see the “Threats Caused 

by HABs and Hypoxia” section of this report.

8.4. Relevant Legislation and Funding Initiatives

In 2010, President Obama announced the EPA-led, interagency Great Lakes Restoration Initiative (GLRI), 

which was designed to increase efforts between 2010-2014 to protect and restore Great Lakes natural 

resources, and included HAB and hypoxia projects. GLRI was extended from Fiscal Year 2015 through 

FY2019, through the GLRI Action Plan II, and allows for further collaborations between Federal, state, and 

local authorities. After the 2014 Lake Erie HAB, $12 million in GLRI funding was provided to Federal and 

state programs to minimize HABs and hypoxia in the western basin of Lake Erie. Specific projects

supported by this funding include upgrading controlled drainage systems, funding best management 

practices (BMPs) at livestock facilities, and planting cover crops. It also provides funding for the

Environmental Quality Incentives Program, a voluntary program through USDA NRCS that provides 

financial and technical assistance to agricultural producers to plan and implement conservation practices 

that improve soil, water, plant, animal, air, and related natural resources on agricultural land and nonindustrial private forestland.

On March 26, 2015, EPA announced the award of 14 GLRI grants totaling over $17 million, to fund projects 

that will improve Great Lakes water quality by preventing phosphorus runoff and solid erosion that 

contribute to algal blooms, and by reducing suspended sediments in Great Lakes tributaries. These 

projects focus on high-priority watersheds and receiving waters with high potential or known risk for HABs 

and hypoxia. The high-priority areas are Fox River-Green Bay, Saginaw River-Saginaw Bay, and Maumee 

River-western Lake Erie. Nutrient-abatement projects in other high-concern areas were also funded.

In 2012, the United States and Canada amended the Great Lakes Water Quality Agreement (GLWQA). The 

agreement addresses HABs and hypoxia, among other issues, via lake-wide management of nutrient 

inputs for more biologically relevant nutrient reduction targets. Nutrient allocations will be made at 

country, state, and provincial levels for watersheds that are at highest risk for HAB and hypoxia 

development.

The Agricultural Act of 2014 (commonly known as the new “Farm Bill”) was passed in February 2014, and 

retained and expanded many existing programs to reduce nutrient and sediment loads into the Great 

Lakes Basin. A new program authorized under the legislation is the Regional Conservation Partnership 

Program (RCPP). RCPP encourages partners to join with agricultural producers in efforts to increase the 

restoration and sustainable use of soil, water, wildlife, and related natural resources. In particular, the 

Secretary of Agriculture selected the Great Lakes Region as a Critical Conservation Area, making more 

conservation funding available to build on existing strong partnerships in the Great Lakes Region and to 

provide approaches and tools for agricultural producers to better manage nutrients and sediment on 

agricultural land. 

8.5. Current Agency Actions and Successes: Prevention, Control, and Mitigation

In the Great Lakes, modeling and monitoring nutrient inputs in Lake Erie are examples of a prevention

strategy to reduce the inputs which may increase HAB and hypoxia. Control efforts address the immediate 

causes of HABs and hypoxia. This includes strategies that directly kill HAB cells or destroy toxins, physically 

remove cells and toxins from the water column, or limit cell growth and proliferation. Mitigation—which 

refers to responding to an existing or ongoing bloom by attempting to restrict, inhibit, or prevent 

associated undesirable impacts on the environment, human health, or human economies and 

communities—is the area of HAB management where the most immediate potential exists to reduce 
43

impacts, given that many such activities are already underway (Seltenrich, 2014). Improved predictions 

of HAB and hypoxia events may also mitigate impacts through advance warnings, providing time for 

treatment and avoidance strategies to be deployed. 

There are numerous efforts in progress through the various Federal agencies that are designed to prevent, 

control, and mitigate HABs and hypoxia in the Great Lakes. For instance, the purpose of the GLRI is to 

target the biggest threats to the Great Lakes ecosystem, including strategies that lead to the reduction of

HABs and hypoxia. A USGS study identifies nutrient sources and stream conditions that promote HABs 

and hypoxia by monitoring stream flow, nutrients, and sediment loads into the Great Lakes, providing 

information that will help to develop future prediction and mitigation strategies. Similarly, the USDA’s

Natural Resources Conservation Service (NRCS) partners with the USGS through the GLRI for monitoring 

water-quality improvements in streams along with edge-of-field monitoring. There has been a lot of 

progress in mitigation, as well as monitoring and modeling of nutrient input, which will lead to mitigation: 

tools to support prevention. The following sections include information on progress to-date towards 

addressing HABs and hypoxia in the Great Lakes. 

The primary strategies for regulating HABs and hypoxia currently include the following: 

• Minimizing land-based nutrients flowing into coastal and inland waters;

• Reducing nitrogen emissions in the airshed to reduce precipitation-related deposition of nitrogen 

compounds from the air to the land;

• Aerating systems and flushing dams to prevent hypoxia; and

• Reducing new introductions of algal species through genetic control (genetically engineering 

species that are purposely introduced into an ecosystem in order to alter the environmental 

tolerances, reproduction, or other processes of undesirable species) and environmental control 

(manipulation of an ecosystem environment, such as altering ecosystem habitat to disfavor 

growth of undesirable species.

8.5.1. Prevention

Prevention strategies in the Great Lakes regulate and examine the factors known to contribute to the 

development of HABs and hypoxia. This section reviews some Federal efforts to prevent HABs and hypoxia 

in the region.

The USDA’s Agricultural Research Service (ARS), in partnership with NRCS, is also conducting edge-of-field 

monitoring of conservation practices in numerous locations in the Western Lake Erie Basin under both 

USDA’s CEAP Watershed Assessment Studies (including instream monitoring in the St. Joseph River 

Watershed in Indiana) and under the NRCS Conservation Innovation Grants Program. Water-quality 

monitoring is designed to detect changes as a result of conservation practices. CEAP Watersheds studies

also examine how conservation practices interact and how collectively affect water quality in small 

watersheds. In addition, from 2008 through 2011 three other CEAP watershed studies in the Western Lake 

Erie Basin conducted by NRCS and USDA’s National Institute of Food and Agriculture (NIFA) helped build 

understanding of conservation and water quality in the region.

USDA NRCS’ CEAP Cropland Assessment conducted an extensive survey and modeling study in 2011 on 

soil conservation and nutrient reduction in the Great Lakes region. The assessment found that 

conservation practices between 2003 and 2006 significantly reduced in-stream loads of phosphorus, 

nitrogen, and sediment—by 20 percent, 21 percent, and 12 percent, respectively. The assessment also 

evaluated remaining conservation-treatment needs in the region. This information is being used by USDA, 

and state and other Federal agencies to improve conservation-program delivery to address HAB and 

hypoxia mitigation in the Great Lakes (USDA, 2011).
44

In 2012, USDA’s NRCS and National Agricultural Statistics Service (NASS) administered a CEAP Cropland

survey focused on the Western Lake Erie Basin, in order to examine additional conservation 

implementation in that region and changes in agricultural management. A detailed assessment of 

conservation effects is being conducted by USDA using that extensive survey data as well as other sources 

to compare with prior treatment and determine progress in the region as well as identify remaining 

conservation concerns. That assessment report is forthcoming and its findings will help to inform future 

conservation programming and planning to address the remaining needs within the Western Lake Erie 

Basin.

Modeling predicts that forage and cover crops, which take up nutrients from surface waters as opposed 

to subsurface waters, reduce both nitrogen and phosphorus losses in runoff (Francesconi et al., 2014).

This is especially relevant in the Great Lakes region, which has some of the most productive agricultural 

soils in the world, but also would be largely unable to support agriculture without drainage. Drainage (e.g., 

tile drains) removes excess water that may otherwise prevent farmers from conduct field operations or 

would inhibit crop growth, but it can lead to the export of agrochemicals and nutrients through another 

pathway. Since 2008, USDA ARS scientists have monitored surface and tile discharges from agricultural 

fields in the St. Joseph River watershed. In contrast to the traditional understanding of tile drainage, which 

that suggests materials move slowly through soil to the tiles, USDA research shows that under certain 

specific conditions, peak water flow through the tiles sometimes occurs at the same time as peak surface 

runoff, suggesting a strong surface connection through the soil (D.R. Smith et al., 2014).

As part of the CEAP, scientists working in the St. Joseph River Watershed compared the effects of two 

conservation practices (no-till and reduced-till agriculture) on water quality. No-till reduced losses of all 

water-quality pollutants except soluble phosphorus (Smith et al., 2015). This can be the case when soils 

have high levels of phosphorous already present from historic management or are stratified at the surface, 

where there is tile drainage, or where soil macropores have developed over time. An APEX modeling 

study, conducted in collaboration with the Greater Wabash River Resource Conservation and 

Development Council at the Wildcat Creek Watershed in Indiana, evaluated how the incorporation of 

additional conservation practices might be used to improve water quality. These studies highlight the 

importance of treating both surface runoff and tile drainage to minimize HABs. 

In the young glacial till landscapes characteristic of the Great Lakes region, closed depressions known 

locally as potholes are pervasive. Water from surface drainage collects at the lowest spot in the pothole, 

keeping the area too wet for farming. Most farmed potholes are drained using subsurface tiles, but some 

also have supplemental drainage from a tile riser (a pipe with holes drilled in its sides) that extends 

vertically above the soil surface. ARS scientists in West Lafayette, Indiana, found that the extent of 

potholes within a watershed was directly related to concentrations or loads of nutrients lost from that 

watershed. USDA ARS research in a CEAP Watershed Assessment Study showed that an alternate 

conservation practice, called a blind inlet, provided greater filtration of surface water from potholes, 

decreasing soluble phosphorous losses by more than 50 percent, total phosphorus loss by 50 to 79

percent, sediment losses by up to 79 percent, and nitrogen loss by approximately 50 percent. In 2012, 

these ARS scientists worked with the NRCS to develop a modified conservation practice standard

(modification to CP 620, Underground Outlet) that is now offered through the Environmental Quality 

Incentives Program (EQIP) in Indiana and Ohio and as an interim practice in some other states.

Extensive efforts to synthesize modeling data are underway through “Annex 4 – Nutrients Subcommittee”

of the GLWQA. As part of this effort, Lake Erie has been elevated to the highest priority due to elevated 

nutrient levels and the large number of HABs being observed. In addition to intensive data-integration 
45

efforts, an ensemble modeling approach with nine models is being applied to different response indicators 

to meet the objectives of the Nutrients Annex.

The USGS SPARROW model helps to illustrate nutrient loading in rivers that flow into the Great Lakes. The 

resulting data can be used to further improve and test NOAA’s HAB models. USGS has also created 

regional groundwater models and a major aquifer-sampling program. USGS projects include spatially 

relevant groundwater testing for nutrients that enter the Lakes through groundwater. Additionally, 

monitoring stations are located in small streams at the edge of agricultural fields where conservation 

practices are being implemented. The close proximity of the stream monitoring site to the field will allow 

for more rapid understanding of the effects of agricultural conservation practices on water quality. The 

study sites—which will run from 2014 through 2018—include the Fox River, which flows into Green Bay; 

a tributary to the Maumee River that flows into the western basin of Lake Erie; and a tributary to the 

Saginaw River that flows into Saginaw Bay. The results of the GLRI effort will be communicated to 

interested stakeholders to help guide similar efforts in the Great Lakes.

Data sharing has become an increasingly important component of research collaborations and is useful

for connecting findings with interested stakeholders. The Great Lakes Observing System (GLOS) was 

created for this exact purpose. GLOS is a regional component of the Integrated Ocean Observing System 

that partners with Federal, regional, academic, and private entities to provide Great Lakes data to 

interested parties, including managers, decision-makers, and the public. NOAA and USGS are among the 

entities that provide data and products to GLOS. 

NOAA’s Great Lakes Environmental Research Laboratory (GLERL) has developed a HAB monitoring 

program for western Lake Erie that collects and distributes critical water-quality and toxicity data to 

regional water managers and other stakeholders on a weekly basis throughout the bloom season. These 

data are also used to validate the short- and long-term HAB forecasting models developed by NOAA’s 

GLERL and National Centers for Coastal Ocean Service (NCCOS) scientists. The central Lake Erie buoy 

provides early warning to the Cleveland Water Department regarding dissolved oxygen levels and 

indications on movement of hypoxic water into drinking-water intakes. NOAA continues to expand and 

improve technologies and sampling efforts to determine conditions that promote HABs and hypoxia.

8.5.2. Control

EPA’s Office of Water has developed analytical methods and advisories for HAB toxins in drinking water

that are relevant to and applicable in the Great Lakes. This was in direct response to the 2014 Toledo 

drinking water closure, due to Lake Erie HABs. The agency is conducting water-treatment research to 

better understand the photochemical fate of toxins (i.e., the effect of light on toxins) and to test ultraviolet 

and solar-based methods of water treatment. The assessment includes efficacy of drinking-water 

treatment, cost-benefit analyses, and development of better testing methods. NOAA is developing natural 

filters for removal of toxins from drinking water and is doing a cost-benefit analysis of various HAB controls 

versus HAB impacts, for use in the Great Lakes and elsewhere.

8.5.3. Mitigation

Prediction and mitigation are interrelated. Prevention refers to acting before a HAB or hypoxic event 

occurs, while mitigation relates to the actions taken to respond to ongoing blooms. Mitigation efforts 

have the most immediate potential to reduce impacts, as they requires real-time management strategies 

and efforts that often are based on data accrued through prevention programs (Seltenrich, 2014).
46

The Great Lakes provide many examples of this relationship. Researchers at NOAA and the Cooperative 

Institute for Limnology and Ecosystems Research4 in Ann Arbor, Michigan, have created the Lake Erie 

Operational Forecast System (LEOFS)5 to predict HABs. The results of this model are published regularly 

by NOAA as a part of the Experimental Lake Erie Harmful Algal Bloom Bulletin.

6 The LEOFS predicted a 

bloom three days before the August 2014 Lake Erie bloom that affected the Monroe, Michigan, watertreatment plant. With information from the model, the treatment plan managers were better able to 

prepare for the influx of toxic water, thereby mitigating the human health effects of the HAB. 

USDA, through the CEAP Watershed 

Assessment Studies, has conducted 

four small watershed-scale studies on 

the effects of conservation practices on 

water quality, water availability, and 

soil quality throughout the Great Lakes 

region. The goals of these projects are

to document measureable waterquality (and related) changes as a 

result of the implementation of 

conservation practices, and to develop 

improved understanding of how 

conservation practices interact within a 

small watershed. USDA NRCS 

partnered with USDA ARS and USDA 

NIFA to conduct this work from 2004 to

the present. One study7 is ongoing in 

the St. Joseph River Watershed (Cedar 

Creek) in Indiana. Many important 

insights for more-effective 

conservation were identified from these studies and are now being used by NRCS in improved modeling 

algorithms, high-quality water-quality data, more-effective conservation practice standards, moreeffective watershed and conservation planning, and comprehensive systems of practices. Each of these 

studies is being applied through conservation programs like the new RCPP and others in the region 

(particularly in the western Lake Erie Basin), where the studies were all conducted.

Agencies are working with Federal, state, and local officials, and other stakeholders, to develop better, 

faster responses to HABs. The CDC’s National Outbreak Reporting System (NORS)8 allows states to report 

human and animal sickness and deaths related to HABs and HAB toxins. To improve disaster preparedness, 

the CDC—with input from state, local, territorial, and tribal health departments—created a Community 

Assessment for Public Health Emergency Response (CASPER) tool. A CASPER survey was conducted by the 

Health Studies Branch of the National Center for Environmental Health (NCEH) at the CDC during the 

Toledo drinking water ban in 2014 to assess impacts of the Lake Erie bloom on Toledo residents (Toledo-

 

4 http://ciler.snre.umich.edu/

5 http://tidesandcurrents.noaa.gov/ofs/leofs/leofs.html

6 http://www.glerl.noaa.gov/res/HABs_and_Hypoxia/lakeErieHABArchive/

7 http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/technical/nra/ceap/ws/?cid=nrcs143_014160

8 http://www.cdc.gov/nors/

Image 8.1. Harmful algae on the shore of Catawba Island, Lake Erie, 

Ohio (Photo courtesy of NOAA)
47

Lucas County Health Department, 2014). The NCEH also helps with emergency-response preparedness 

and CASPER training for local, state, tribal, and territorial health departments. In 2014, NOAA NCCOS 

helped states respond to western Lake Erie HABs by doing toxin analysis in collaboration with labs at State 

University of New York – College of Environmental Science and Forestry, as well as by developing response 

plans and outreach materials.
48

9. Conclusion

Marine and freshwater HABs and hypoxia present serious challenges to protecting human, economic, 

animal, and environmental health across the United States. The direct economic effects of HABs alone in 

American communities include losses in income from commercial fishing, recreation, and tourism 

industries; public health costs of illness; expenses for monitoring and management; increased costs for 

drinking water treatment; and declining property values (Environmental Protection Agency, 2015). This 

amount does not include the costs of preventing or mitigating the causes of these events, which can run 

into the millions of dollars. As complex scientific processes, HABs and hypoxia present unique challenges 

to researchers for determining related causes, impacts, and best management practices. HABs and 

hypoxia also create social costs, including short- and long-term impacts on community development and 

social structure. 

Although HABs and hypoxia occur naturally, it is clear that humans influence the severity and frequency 

of these events. The recommendations in this report are a roadmap for protecting American citizens and 

the country as a whole from this growing threat. The IWG-HABHRCA will use this action strategy to 

produce implementation plans, including timelines, for addressing individual components of the

recommendations. Finally, the group will continue to engage with stakeholders around the country to 

determine how interagency efforts can be most responsive to evolving concerns and community needs 

related to HABs and hypoxia. 
49

Appendix 1

HABs, Toxins, and their Effects

HAB Taxa Toxin/Bioactive 

Compound

Human Health 

Effects

Animal 

Impacts

Environmenta

l Effects

Economic 

Impact

Impacted 

Areas in 

U.S.

FRESHWATER

Cyanobacteria 

Microcystins, 

Cylindrospermopsin

, Anatoxin-a, 

Saxitoxin(s), 

geosmins, 

methylisoborneol

Liver and 

kidney toxicity, 

neurotoxic, 

paralysis, 

gastrointestinal

, dermatitis

Dog, farm 

animals, 

wildlife,

and pet 

mortality, 

fish kills

Water 

discoloration, 

foul odors

Loss of 

tourism, 

contamination 

of drinking 

water requiring 

additional 

expensive 

water 

treatment or 

alternate 

water sources, 

make farmed 

and wildcaught 

freshwater fish 

inedible

(including bad 

taste)

Great Lakes 

and many 

inland water 

bodies

Haptophytes 

(e.g., Prymnesium 

parvum, 

Chrysochromulin

a polylepis)

Prymnesins, 

Ichthyotoxins Fish kills

Water 

discoloration, 

foam 

formation

Loss of fishing 

income, 

cleanup costs

TX,PA, OK, 

NM, AK, AL, 

CO, GA, NC, 

SC, WY, FL 

and NE

Chlorophytes 

Microalgae (e.g., 

Volvox, 

Pandorina)

Discolored 

water, 

localized 

hypoxia

Small 

eutrophic 

ponds

Macroalgae

(e.g., Cladophora) Bad odor

Associate

d with 

outbreaks 

of avian 

botulism

Fouls water 

intakes and 

piles up on 

beaches, 

localized 

hypoxia

Loss of 

recreational 

use and cleanup costs, 

clogged water 

intakes, bad 

odor

Great Lakes 

except Lake 

Superior, FL 

inland lakes

Euglenophytes 

(Euglena 

sanguinea)

Euglenophycin Not 

characterized Fish kills Water 

discoloration

Loss of 

aquaculture 

operations

Texas, North 

Carolina, 

Great Lakes
50

HAB Taxa Toxin/Bioactive 

Compound

Human Health 

Effects

Animal 

Impacts

Environmenta

l Effects

Economic 

Impact

Impacted 

Areas in 

U.S.

Dinoflagellates 

(e.g., Peridinium 

polonicum [syn. 

Peridiniopsis 

polonicum, 

Glenodinium 

Gymnodinium])

Fish kills Water 

discoloration

Discolored 

water in OK

Diatoms Didymosphenia 

geminata

Produces large 

amounts of 

extracellular 

stalk material 

that piles up 

on beaches

Loss of 

recreational 

use

Nuisance 

blooms 

found in 

streams and 

rivers

MARINE

Pseudo-nitzschia Domoic Acid

Gastrointestinal 

and central 

nervous system 

effects 

(Amnesic 

Shellfish 

Poisoning)

Sea bird 

and 

marine 

mammal 

mortality

Closure of 

shellfish 

harvesting, loss 

of tourism 

income,

wildlife 

rehabilitation

West Coast, 

Florida, 

Maine

Dinophysis; 

Prorocentrum

Okadaic acid; 

Dinophysotoxins

Gastrointestinal 

distress

Closing of 

shellfish 

fisheries

Oregon, 

Texas, 

Washington

Gambierdiscus; 

Prorocentrum; 

Ostreopsis

Ciguatoxins

Sensory and 

gastrointestinal 

dysfunction 

(Ciguatera Fish 

Poisoning)

Possible 

marine 

mammal 

illness

Bans on fish 

sales from 

affected areas,

cost of medical 

treatment, loss 

of protein 

source

Florida, Gulf 

Coast, 

Hawaii, 

Pacific, and 

Caribbean

Karenia Brevetoxins

Neurotoxicity:

Gastrointestinal 

and sensory 

effects 

(Neurotoxic 

Shellfish 

Poisoning),

respiratory 

effects

Fish kills; 

manatee, 

dolphin, 

marine 

turtle, and 

bird 

deaths

Water 

discoloration

Loss of tourism 

income; 

Removal of

dead fish from 

beaches, 

shellfish 

fisheries 

closing,

increased 

emergency 

room visits due 

to respiratory 

and 

gastrointestina

l illness,

wildlife 

rehabilitation

Gulf of 

Mexico and 

Atlantic

coast up to 

North 

Carolina
51

HAB Taxa Toxin/Bioactive 

Compound

Human Health 

Effects

Animal 

Impacts

Environmenta

l Effects

Economic 

Impact

Impacted 

Areas in 

U.S.

Alexandrium; 

Gymnodinium; 

Pyrodinium 

bahamense

Saxitoxins

Respiratory 

paralysis, death 

(PSP)

Marine 

mammal 

deaths

Loss of 

shellfish 

harvesting 

income; 

human illness 

from 

recreational 

harvest; 

closure 

recreational 

puffer fish 

harvest in FL

Pacific 

coast,

including 

Alaska; NE 

Atlantic 

coast; 

Florida

Karlodinium Karlotoxins Fish toxin Fish kills Water 

discoloration

Atlantic and 

Gulf Coasts

Aureoumbra 

lagunensis--Texas 

Brown Tide

Not characterized

Water 

discoloration; 

Loss of 

submerged 

aquatic 

vegetation

Texas, 

Florida

Aureococcus 

anophagefferens-

-Long Island 

Brown Tide

Not characterized

Water 

discoloration;

seagrass and 

shellfish dieoffs; hypoxic 

zones

Loss of 

shellfish 

harvesting 

income; 

interference

with 

restoration

Mid-Atlantic 

coast

Akashiwo 

sanguineum Surfactants

Suspected 

respiratory 

irritant

Migratory 

bird 

deaths, 

including 

protected 

species

Water 

Discoloration; 

Foam 

formation

Costs 

rehabilitation 

of protected 

bird species

Pacific Coast

Heterosigma 

akashiwo Ichthyotoxins Fish kills Water discoloration

Loss of fish net 

pen 

mariculture

Washington

; MidAtlantic 

coast

Other 

Raphidophytes: 

Chattonella, 

Fibrocapsa

Brevetoxins; 

Ichthyotoxins Fish kills Water 

discoloration

Mid-Atlantic 

coast

Prorocentrum 

minimum--

Mahogany Tides

Not characterized

Mortality 

of spat in 

shellfish 

hatcheries

Water 

discoloration

Loss to 

shellfish 

hatcheries

Chesapeake 

Bay
52

HAB Taxa Toxin/Bioactive 

Compound

Human Health 

Effects

Animal 

Impacts

Environmenta

l Effects

Economic 

Impact

Impacted 

Areas in 

U.S.

Alexandrium 

monilatum Goniodomin

Fish and 

shellfish 

mortality

Water 

discoloration

Gulf of 

Mexico and 

Atlantic

coast up to 

New Jersey

Cochlodinium Not characterized Fish kills Water 

discoloration

Severe impacts 

on fish and

shellfish 

mariculture in 

Asia

West Coast, 

Mid-Atlantic

Macroalgae H2S, dopamine Respiratory 

impacts

Impair 

nesting 

protected 

species

Shade 

submerged 

aquatic 

vegetation, 

cause hypoxia

Removal from 

beaches; loss 

of tourism 

income

All coasts

Marine 

cyanotoxins 

(formerly 

Lyngbya)

Dermatotoxins Impact divers 

on coral reefs

Overgrow 

coral reefs

Loss of tourism 

income

South 

Florida

Appendix 2

HAB-Related Human Illnesses

Toxin Vector Occurrence Acute Toxicity Long-Term Health 

Impacts

Susceptible

Populations

Susceptible 

Regions

Anatoxin-a 

Drinking 

water, 

Recreational 

waters, 

Dietary 

supplements

Low

Tingling, 

burning, 

numbness, 

drowsiness, 

incoherent 

speech, 

respiratory 

paralysis leading 

to death

Unknown Recreational 

water users

Great Lakes, 

Continental 

U.S. ponds 

and lakes

Brevetoxins 

Marine 

Aerosols, 

Recreational 

waters

High

Acute eye 

irritation, 

respiratory 

distress, asthma 

exacerbation

Unknown

Lifeguards, 

beachgoers, 

coastal 

residents

Gulf of 

Mexico
53

Brevetoxins Shellfish Low

Neurotoxic

Shellfish 

Poisoning: 

Nausea, 

vomiting, 

diarrhea, 

numbness of 

lips, tongue, 

and throat, 

muscular aches, 

fever, chills, 

muscle pains, 

reduced heart 

rate, and pupil 

dilation

Unknown

Recreational 

shellfish 

harvesters

Gulf of 

Mexico, 

southeastern 

Atlantic coast

Ciguatoxins Fish High

Ciguatera Fish 

Poisoning: 

Abdominal pain, 

nausea, 

vomiting, 

diarrhea; 

paresthesia, 

temperature 

dysesthesia, 

pain weakness; 

and 

bradycardia, 

hypotension

Recurrent 

symptoms of 

months to years, 

including 

neurological and 

neurophysiological 

symptoms (e.g., 

malaise, depression, 

headaches, myalgia, 

and fatigue)

Islanders 

subsistent on 

local 

fisheries, 

tourists, 

anglers in 

endemic 

areas

Florida Keys, 

Caribbean, 

Hawaii, 

Pacific 

Islands, Gulf 

of Mexico 

(Flower 

Garden 

Banks)

Cyanobacterial 

LPS

Drinking 

water, 

Recreational 

Waters

Medium

Abdominal pain, 

vomiting and 

diarrhea, acute 

dermatitis

Unknown Recreational 

water users

Great Lakes, 

Continental 

U.S. ponds 

and lakes

Cylindospermospins

Drinking 

water, 

recreational 

waters, 

dietary 

supplements

Medium

Abdominal pain, 

vomiting and 

diarrhea, liver 

inflammation 

and 

hemorrhage, 

acute 

pneumonia, 

acute dermatitis

Malaise, anorexia, 

liver failure leading 

to death

Children, 

dialysis 

patients, 

liver disease, 

recreational 

water users

Great Lakes, 

Continental 

U.S. ponds 

and lakes

Domoic acid Shellfish Low

Amnesic 

Shellfish 

Poisoning: 

Vomiting, 

diarrhea, 

abdominal pain; 

confusion, 

disorientation, 

memory loss

Anterograde 

memory deficit, 

temporal lobe 

epilepsy, kidney 

disease

Elderly, 

children, 

pre-existing 

renal 

disease, 

subsistence 

and 

recreational 

harvesters

Northwest, 

California, 

Northeast, 

Gulf of 

Mexico
54

Microcystins 

Drinking 

water, 

recreational 

waters, 

dietary 

supplements

High

Abdominal pain, 

vomiting and 

diarrhea, liver 

inflammation 

and 

hemorrhage, 

acute 

pneumonia, 

acute 

dermatitis, 

seizures leading 

to coma and 

death

Hepatocellular 

carcinoma, liver 

failure leading to 

death

Children, 

dialysis 

patients, 

pre-existing 

liver disease, 

recreational 

water users

Great Lakes, 

Continental 

U.S. ponds 

and lakes

Okadaic acid / 

Dinophysistoxins Shellfish Low

Diarrhetic 

Shellfish 

Poisoning:

Nausea, 

vomiting, 

diarrhea, 

abdominal pain 

accompanied by 

chills, headache, 

and fever

Gastrointestinal 

tumor promotor

Recreational 

shellfish 

harvesters

Northeast, 

Gulf of 

Mexico, 

Northwest

Saxitoxins Shellfish Medium

Paralytic 

Shellfish 

Poisoning: 

tingling, 

burning, 

numbness, 

drowsiness, 

incoherent 

speech, 

respiratory 

paralysis leading 

to death

Unknown

Children, 

recreational 

harvesters

Alaska,

Northwest, 

Northeast, 

California, 

Northeast 

Florida

Yessotoxins, 

Pectenotoxins Shellfish Unknown

Not 

documented as 

toxin in 

humans, but cooccur in DSP 

shellfish and are 

highly toxic to 

mice

Unknown Unknown Northeast, 

Northwest
55

Appendix 3

Agency Activities on HABs and Hypoxia
56

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Program Title

(brief description) Program Activities

DHHS CDC HABs

National Outbreak 

Reporting System

(NORS)

CDC initiated waterborne and foodborne disease 

outbreak surveillance systems in the 1970s. U.S. states 

and territories voluntarily report to these systems via 

the electronic NORS, which receives aggregate data on 

human cases and their exposures, including exposures 

to harmful algal blooms (HABs) or HAB toxins. The One 

Health Harmful Algal Bloom System (OHHABS) is being 

developed for single case-level reporting of human and 

animal illness, and relevant environmental data. 

OHHABS is being programmed to inform restoration 

activities in the Great Lakes but will accessible to all 

states via NORS. The pilot version of the system is being 

tested in preparation for a 2016 launch.

DHHS CDC HABs

Great Lakes State 

Health Surveillance 

Capacity

CDC has partnered with the Council of State and 

Territorial Epidemiologists (CSTE) since 2013 to place 

and provide technical support for epidemiology fellows 

in Great Lakes states, including Indiana, Illinois, 

Michigan, Minnesota, New York, Ohio, and Wisconsin. 

The activity is supported by the Great Lakes Restoration 

Initiative. Fellows focus on waterborne disease 

detection, investigation, response and reporting. The 

fellowship has expanded state waterborne disease 

reporting and analytic capacity; improved state health 

surveillance for harmful algal blooms; and ensured 

dedicated staff time for waterborne disease 

surveillance and coordination activities. 

DHHS CDC HABs Health 

Communications

CDC’s health communications activities related to HABs 

include the preparation of a HAB website with 

information for public health practitioners, clinicians, 

and the general public, and the expansion of the 

Drinking Water Advisory Communications Toolbox 

(DWACT) to include information about HAB-related 

drinking water advisories. The DWACT was created 

through a collaborative effort among CDC, EPA, the 

American Water Works Association, the Association of 

State and Territorial Health Officials, the Association of 

State Drinking Water Administrators (ASDWA), and the 

National Environmental Health Association (NEHA).
57

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Program Title

(brief description) Program Activities

Multiple CDC, EPA, NOAA HABs Interagency Analytic 

Workgroup

Additional research is needed to fully characterize and 

understand the health risks from drinking water 

provided by public water systems when that water is 

contaminated with cyanobacterial toxins. There is a 

need to establish standardized biological sample 

collection and analysis protocols to support assessment 

of toxin-associated health effects. Multiple federal 

agencies are working together to assess sampling and 

analytical capabilities related to analysis of biological 

specimens collected from human and animals exposed 

to cyanobacteria toxins via contaminated water, 

including drinking water. The goal is to combine 

expertise to develop robust analytic methods to detect 

biological evidence of exposure to cyanobacterial 

toxins, to optimize laboratory and emergency response 

capacity in the collection, analysis, and response to 

harmful algal bloom-related illnesses.

DHHS CDC HABs

Method development, refinement, and validation for 

detecting human exposures to HAB toxins through the 

detection of toxins and specific biomarkers in clinical 

samples. Current methods approved for use include the 

detection of saxitoxin, neosaxitoxin, tetrodotoxin, and 

gonyautoxins (1-4), which have been applied to 

individual cases to confirm suspected HAB exposures.

DHHS FDA HABs

Method development, refinement, and validation for 

detecting HAB toxins; Improving understanding of HAB 

toxin sources and vectors that impact seafood and 

dietary supplement safety

DHHS FDA HABs

Developed, evaluated, and validated rapid screening 

for HAB toxins in seafood, thereby improving 

regulatory monitoring, surveillance programs, and 

outbreak response. For example, FDA developed an 

onboard screening dockside testing program for PSP

toxins in shellfish, which led to reopening of a large 

portion of Georges Bank in 2013 to safe commercial 

harvest of clams.
58

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Program Title

(brief description) Program Activities

DOC NOAA HABs

The NOAA Northwest Fisheries Science Center has 

established coastal monitoring program called ORHAB 

(funded by MERHAB) for outer WA coast monitoring 

and a new monitoring partnership called SoundToxins 

for the early warning of harmful algal blooms in Puget 

Sound. The NOAA National Centers for Coastal Ocean 

Science Ecology and Oceanography of Harmful Algal 

Blooms (ECOHAB) program provided 3 years of funding 

to develop the Puget Sound Harmful Algal Bloom (PSAHAB) project to understand environmental controls 

on the benthic (cyst) and planktonic life stages of the 

toxic dinoflagellate Alexandrium, and evaluate the 

effects of climate change on the timing and location of 

blooms. ECOHAB funded a 3-year project on the 

ecology of Heterosigma akashiwo, a fish-killing 

flagellate, that has resulted in millions of dollars lost to 

net-penned salmon in Puget Sound.

DOC NOAA HABs

National 

Phytoplankton 

Monitoring Network

The PMN was established to monitor phytoplankton 

and harmful algal blooms and promote environmental 

stewardship though the use citizen volunteers. PMN 

volunteers are trained by NOAA staff on sampling 

techniques and identification methods for over 50 

genera, including 10 potentially toxin producing 

genera, of dinoflagellates and diatoms on the 

volunteers watch list. Currently, 250 sites in 22 states 

and American territories including 52 schools, 15 

universities, 298 civic groups and 40 state and Federal

agencies collect phytoplankton and environmental 

data. Since the inception of the program in 2001, more 

than 275 algal blooms and 15 toxic events have been 

reported by PMN volunteers.

DOC NOAA HABs National Analytical 

Response Team (ART)

NOAA’s ART provides rapid and accurate identification 

and quantification of marine algal toxins in suspected 

HABs, and related marine animal mortality events and 

human poisonings. From 2009 to 2014, ART received 

over 4000 samples from state and Federal government 

agencies, non-governmental organizations, and 

academic partners for determination of toxins 

associated with harmful algae. In addition to water 

samples, marine toxins were analyzed in samples from 

marine and freshwater algae, shellfish, fish, cetaceans, 

pinnipeds, birds and sea turtles. ART has analyzed 

samples from almost every US coastal state and the 

U.S. Virgin Islands and from countries including Canada, 

United Kingdom, Morocco, Argentina, Chile, Mexico, 

Uruguay, Peru, and El Salvador.
59

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Program Title

(brief description) Program Activities

DOC NOAA HABs Technology Transfer 

Team

The Technology Transfer Team completed rigorous, 

international inter-laboratory trials in partnership with 

interagency organizations, Federal agencies and private 

businesses to bring the receptor binding assay for PSP 

toxins to national and international regulatory 

approval; and guided its commercialization to assure 

American shellfish are safe for American citizens and 

export throughout the world. The team also provided 

training on use of the method to more than 30 

countries through formal agreement with the 

International Atomic Energy Agency to promote safe 

food supply and increased economic growth through 

the export of fisheries products and to the Southeast 

Alaska Tribal partnership to enable monitoring of 

subsistence resources.

DOC NOAA HABs

The National Centers for Coastal Ocean Science 

(NCCOS) has provided base funding (labor and 

operational funds) for development of HAB forecasts; 

NOAA anticipates this to continue through fiscal year 

2015. NOAA is starting new research projects on using 

satellite data to improve the frequency of the forecasts 

for the operational Gulf of Mexico (with funding by the 

NASA ROSES Health and Air Quality program) and in 

coordination with EPA, NASA, and USGS on freshwater 

systems. (This includes funding by NASA Ocean Biology 

program and tentative support through fiscal year 

2016funding from the Great Lakes Restoration 

Initiative). NOAA is also working with EPA on systematic 

approach to either warning state health/water quality 

on cyanobacteria blooms and allowing them to 

evaluate patterns and trends in lakes and estuaries that 

are at risk.

DOC NOAA HABs

Make satellite coverage of ocean and coastal zones 

more comprehensive and combine it with existing data 

to enable quantifiable estimates of HABs (much of this 

has been funded by NASA). Plan to transfer promising 

new monitoring and prediction technology and 

approaches from research to operational HAB forecasts 

for Gulf of Mexico, Lake Erie, Chesapeake Bay, Puget 

Sounds, Pacific Northwest, and California.

DOC NOAA HABs

Ecology and 

Oceanography of

Harmful Algal Blooms 

(ECOHAB)

Developing a better understanding of HAB causes and 

impacts that form the basis for better management to 

reduce HABs and their impacts.

DOC NOAA HABs

Monitoring and Event 

Response for Harmful 

Algal Blooms 

(MERHAB)

National, competitive extramural research program 

that builds capacity for enhanced HAB monitoring and 

response in state, local, and tribal governments.
60

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Program Title

(brief description) Program Activities

DOC NOAA HABs

Prevention, Control, 

and Mitigation of 

Harmful Algal Blooms 

(PCMHAB)

National, competitive extramural research program 

that develops new methods of HAB prevention, 

control, and mitigation. It also addresses the 

socioeconomic impact of HABs and efforts to reduce 

HAB impacts.

DOC NOAA HABs Event Response

Provides immediate assistance for managing HAB 

events and advancing the understanding of HABs when 

they occur.

DOC NOAA HABs

NESDIS/STAR has provided support in FY15 to transfer 

VIIRS remote sensing data for GOMx HAB forecasts into 

operations. STAR is currently planning support for 

FY16+ to acquire and process remote sensing data (e.g., 

from Sentinel-3/OLCI) that meets HAB requirements 

for expanded geographic regions.

DOC NOAA Hypoxia

Coastal Hypoxia 

Research Program 

(CHRP)

National, competitive extramural research program 

that develops understanding of hypoxia causes and 

impacts that form the basis for better management to 

reduce hypoxia and its ecological and socioeconomic 

impacts. Includes all coastal systems except the large 

hypoxic zone along the northern Gulf of Mexico 

continental shelf.

DOC NOAA Hypoxia

Northern Gulf of 

Mexico Ecosystems 

and Hypoxia 

Assessment Program 

(NGOMEX)

National, competitive extramural research program 

that develops understanding of the causes and impacts 

of the northern Gulf of Mexico hypoxic zone, that form 

the basis for better management to reduce the hypoxic 

zone and its ecological and socioeconomic impacts.

DOC NOAA Hypoxia

Continue to convene workshops to obtain stakeholder 

needs that drive research prioritization, and 

disseminate advanced knowledge and tools for hypoxia 

mitigation to regional managers and interagency 

management networks such as the Gulf Hypoxia Task 

Force or the Landscape Conservation Cooperative.

DOC NOAA HABs

Studies molecular ecology of HABs in the Great Lakes 

and makes improvements to monitoring HABs and 

toxicity in the Great lakes. Monitors six routine stations 

in the western basin of Lake Erie weekly during blooms 

season and supplies data that supports the predictive 

models in Lake Erie. Developing a three-dimensional

lagrangian particle transport model to effectively 

predict HAB advection as part of the Lake Erie 

Operational Forecasting System, which is set to go 

operational in fiscal year 2015.
61

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Program Title

(brief description) Program Activities

DOD USACE HABs

Responding to HABs in response to public 

reports/complaints in close coordination with State 

water quality/public health agencies. Response 

programs developed by individual USACE 

Divisions/Districts. USACE Engineer Research and 

Development Center available to support 

Divisions/Districts in assessing HAB impacts to USACE 

Civil Works Projects (e.g., water quality modeling, 

remote sensing, and technical assistance). General 

water quality monitoring and HAB response to meet 

authorized project purposes and recreation mission 

requirements.

DOD Navy HABs

Studies the variability of in situ and remotely sensed 

spectral optical properties to identify dinoflagellates 

through field sampling and improvement of remote 

sensing techniques. Dinoflagellate information has 

been incorporated into Naval Research Laboratory’s

ecological-circulation models for better 

understanding/prediction.

DOI

Bureau of Ocean 

Energy 

Management 

(BOEM)

Hypoxia

Gulf Oxygen 

Deepwater 

Experiment

Study plan pending approval: To address noted data 

gaps that addresses deepwater oxygen dynamics such 

as in the Oxygen Minimum Zone in the Gulf, whereas 

the Louisiana-Texas Shelf Physical Oceanography 

Program shelf studies were on the shallower hypoxic 

zone.

DOI NPS HABs and 

hypoxia

Outreach and 

Education

Of the 407 NPS units, there are 86 units that are 

considered ocean, coastal, or Great Lake parks, in 

addition to other park units that have extensive surface 

water bodies. HABs have the potential to influence all 

of these park units at various levels, and it is therefore 

important to prepare for these events in order to 

preserve our resources. The National Park Service is 

creating a website containing a public health and 

ecological HAB events reporting system. It also 

provides a point of contact for park managers to 

partner with local and state health and environmental 

agencies who will provide park personnel with 

technical assistance for the management of HAB 

events. Outreach materials (brochures, interpretive 

displays, and materials) on HABs, their causes, the 

effects on the ecosystem, and the many ways to reduce 

or stop nonpoint source pollution, many of which are 

simple to implement.
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Program Title

(brief description) Program Activities

DOI USGS HABs and 

hypoxia

National Water 

Quality Program

USGS conducts long-term monitoring of nutrients and 

other water quality characteristics in surface and 

groundwater networks. The sources and quantities of 

nutrients delivered by streams and groundwater to the 

Great Lakes and estuaries are monitored at 106 sites. 

Annual updates from the monitoring sites will be made 

available to the public, including nutrient 

concentrations, loads, and yields. These data, along 

with data aggregated from numerous other agencies, 

are used to evaluate trends in critical water quality 

parameters including nutrients and sediment. Realtime measurements for dissolved oxygen and 

temperature are collected at over 500 and 2000 

locations, respectively. USGS is pioneering new field 

sensor methods and systems for monitoring and 

delivering real-time nutrient data. The USGS SPARROW 

model quantifies nutrient sources and sediment loads 

to coastal areas, the Great Lakes, and inland lakes in the 

Eastern United States. SPARROW has also been linked 

to an online Decision Support System, which allows 

direct exploration of the potential benefits of nutrient 

management for systems including the Chesapeake 

and the Mississippi, other coastal rivers, and the Great 

Lakes.

DOI USGS HABs and 

hypoxia

National Water 

Quality 

Program/National 

Water Quality 

Assessment

USGS collects fish-, aquatic macroinvertebrate-, and 

algae-community samples, and conducts stream 

physical habitat surveys to assess the effects of multiple 

stressors—including algal toxins—on aquatic 

organisms in streams in several ecoregions. 

DOI USGS HABs

National Water 

Quality Program/

Cooperative Water 

Program

HAB research is conducted in at least 20 USGS Water 

Science Centers. Studies include both short- and longterm projects focused on quantifying blooms and 

associated toxins and taste-and-odor compounds, and 

understanding causal factors. Many studies employ 

new and developing sensor technology to detect algal 

pigments. For example, a study of the primary drinking 

water supply for Wichita, Kansas combined long-term 

discrete and continuous water-quality data to develop 

models that estimate the probability of microcystin 

occurrence in near real time. 
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Program Title

(brief description) Program Activities

DOI, USDA USGS, USDANRCS

HABs and 

hypoxia GLRI

GLRI assesses the impacts of agricultural management 

practices, climate change, and land use change on the 

timing and magnitude of delivery of nutrients and 

sediments to the Great Lakes at 30 sites. The group 

works with NOAA, EPA, states, universities, and NGOs 

to understand how nutrient and sediment loading from 

the Great Lakes watershed affect hypoxia, HABs and 

biological communities in the near-shore environment. 

Edge-of-field studies in the GLRI priority watershed 

quantify phosphorus, nitrogen, and sediment to 

evaluate nutrient reduction projects on agricultural 

land. Rapid sharing of edge-of-field monitoring results 

with local stakeholders allow for adaptive 

implementation.

DOI USGS HABs Toxic Substances 

Hydrology Program

The Toxic Substances Hydrology Program supported 

research investigates the origins, occurrence, 

transport/fate, effects, and mitigation of HABs and 

associated toxin mixtures. In doing so new methods are 

being pioneered including toxin-specific analytical 

methods and development of targeted and nontargeted ground-to-space field and laboratory 

methods. Current and planned research, which 

includes investigations of metabolites and related 

biota, characterizes the spatial/temporal extent of 

understudied aspects of toxins associated with HABs; 

evaluates environmental controls responsible for HAB 

proliferation and associated toxin production; and 

evaluates environmental health implications and 

impacts. In addition to contributing to basic 

understandings of the biogeochemical underpinnings 

of algal toxin occurrence and associated environmental 

health threats, this information can be utilized to assist 

with standardization of study designs, field, laboratory, 

and interpretative techniques and to inform mitigation 

activities. Current and planned collaboration is ongoing 

with multiple federal and state agencies and tribes as 

well as through outreach efforts such as participation 

on the Inland HAB Discussion Group. Industry 

collaborations are fostered to facilitate acquisition of 

lower cost, higher throughput screening assays and 

more advanced interpretative capabilities where TSHP 

provides validation support for the benefit of program 

research and stakeholder collaboration.

DOI USGS HABs

Energy, Mineral, and 

Environmental 

Health/Toxic 

Substances 

Hydrology Program

Pioneer new field monitoring methods (sensors), 

assessment techniques, and laboratory methods 

needed to address harmful algal bloom issues in 

freshwaters. New methods include a multi-toxin 

method that can quantify cyanotoxin mixtures, and 

DNA- and RNA-based molecular methods for detecting 

microcystin and microcystin producers.
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Program Title

(brief description) Program Activities

DOI USGS HABs Ecosystems

USGS has ongoing research characterizing ecological 

and food web impacts of cyanotoxins. For example, a 

USGS study in Upper Klamath Lake demonstrated a link 

between microcystin and reduced young-of the year 

recruitment of federally endangered suckers.

NSF

Joint initiative 

between NSF

and NIEHS

HABs

Oceans and Human 

Health (OHH) 

Initiative and the 

NSF's Division of 

Ocean Sciences

The NIEHS supports multiple studies focused on the 

effects of HAB toxins on human and mammalian 

physiology, development of biomarkers for chronic 

toxin exposure, and the design and testing of novel 

technologies for in situ detection of algal toxins in fresh 

and salt water environments. For example, a number of 

ongoing studies are supported that analyze the effects 

of domoic acid on neurotoxicity as well as cognitive 

impacts in human cohorts, non-human primates and 

rodent models. Also, NIEHS is accepting unsolicited 

applications for support and use of time sensitive 

mechanism to allow research support for unanticipated 

bloom events.

NSF NSF HABs and 

hypoxia

Ocean Observatories

Initiative and the 

National Ecological 

Observatory Network

Provides environmental data for studies of HABS (both 

marine and freshwater) and hypoxia.

NSF NSF HABs

Division of Ocean 

Sciences (OCE), NSF 

Ocean Observatories

Initiative

Observational capabilities for research in marine 

systems.

NSF NSF HABs

Directorate for

Geosciences, 

Prediction and 

Resilience Against 

Extreme Events 

(PREEVENTS)

Focused interdisciplinary research projects.

NSF NSF HABs

Division of Biological 

Infrastructure, 

National Ecological 

Observatory Network

(NEON) 

Observational capabilities for ecological research.

NSF NSF HABs Division of Ocean 

Sciences

Research Support, unsolicited proposal in marine 

ecology.

NSF NSF HABs and 

hypoxia

Collaboration 

between NSF GEO, 

SBE, and ENG 

directorates, as well 

as USDA NIFA.

Program supporting interdisciplinary research to 

understand and predict the interactions between the 

water system and climate change, land use, the built 

environment, and ecosystem function and services 

though research and models. Several research projects 

are focused on nutrient movement and hypoxia 

mitigation strategies. 
65

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Program Title

(brief description) Program Activities

NSF NSF HABs

Ocean and Human 

Health Initiative, a 

collaboration 

between NSF's 

Division of Ocean 

Sciences, and the 

National Institute for 

Environmental 

Health Sciences

Studies of the effects of HAB toxins on human and 

mammalian physiology, development of biomarkers for 

chronic toxin exposure, and the design and testing of 

novel technologies for in situ detection of algal toxins in 

fresh- and salt-water environments. Also accepting 

unsolicited applications for support and use of time 

sensitive mechanism to allow research support for 

unanticipated bloom events.

USDA NIFA and ARS HABs

Support of extramural and intramural research on the 

effects of HABs and HAB toxins on food safety, 

aquaculture, and livestock.

USDA ARS HABs and 

hypoxia

Research on nutrient management, nutrient 

contribution to hypoxia, and aquaculture. Long-Term 

Agro-Ecosystem Research (LTAR) and Watershed 

Research Centers.

USDA NIFA HABs and 

hypoxia

Research support for studies of the effects of nutrient 

cycling, climate change, and nutrient management for 

agriculture. 

USDA NRCS HABs and 

hypoxia

Conservation 

Technical Assistance 

(planning); 

Environmental 

Quality Incentives 

Program;

Conservation 

Stewardship 

Program;

Agricultural 

Conservation 

Easement Program

Regional 

Conservation 

Partnership Program

NRCS provides conservation planning assistance to 

agricultural producers on cropland, grazing land, and 

for confined livestock operations. NRCS also has 

financial assistance programs to help producers 

implement and install practices. These programs are all

voluntary and are incentive-based. For confined 

livestock systems, this includes, but is not limited to,

practices such as waste storage structures, and 

associated practices like roofs and covers, roof runoff 

management, diversions, and a nutrient management 

plan for the utilization of manure.

On cropland, this may include agronomic practices such 

as residue management, cover crops, conservation 

cropping systems, and nutrient management; buffer 

practices like filter strips and riparian forest buffers; 

water management practices such as grassed 

waterways, grade stabilization structures, drainage 

water management, blind inlets (to replace surface 

inlets), wetland restoration and creation; and 

prescribed grazing systems and associated practices for 

grazing land. NRCS also assists farmers financially with 

edge-of-field water quality monitoring.
66

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Program Title

(brief description) Program Activities

USDA NRCS HABs and 

hypoxia

Great Lakes 

Restoration Initiative, 

Mississippi River 

Basin Healthy 

Watershed Initiative, 

National Water 

Quality Initiative, etc.

Under various water quality initiatives, NRCS and its 

partners help producers in selected watersheds to 

voluntarily implement conservation practices that 

avoid, control, and trap nutrient runoff; improve 

wildlife habitat; and maintain agricultural productivity.

These initiatives utilize NRCS programs such as the 

Environmental Quality Incentives Program (EQIP) and 

the Conservation Stewardship Program (CSP) within 

targeted watersheds to provide technical and financial 

assistance.

USDA NIFA and ARS HABs and 

hypoxia

Supports research on best management practices for 

nutrient management, aquaculture, and plant 

breeding, among others. Specific concerns addressed 

by this research include manure management from 

animal feeding operations and water use and 

conservation on irrigated cropland. 

USDA

NRCS, ARS

(partnership 

with The Nature 

Conservancy)

HABs and 

hypoxia

CEAP— Wildlife —

Western Lake Erie 

Basin

The on-going Nature Conservancy-led Western Lake 

Erie Basin CEAP-Wildlife project is being conducted to 

assess and forecast benefits of NRCS conservation 

practices to stream fish communities, to help advance 

strategic conservation of riverine ecosystems. A similar 

project for the Saginaw Bay was already completed. In 

this WLEB CEAP Wildlife project, using pre-existing 

water quality and stream fish community data, the 

effort is linking SWAT modeling with fish community 

condition at small watershed scales (NHD+ scale) to 

reveal relationships between conservation practice 

implementation and fish community response within 

the streams. The effort will provide science-based 

estimates of the priorities, scope and costs of restoring 

stream fish communities throughout the Western Lake 

Erie Basin watershed. Coordination with other groups 

is evaluating connections to the Lake Erie water quality.

EPA EPA HABs and 

hypoxia

Water Quality 

Management

Diversified approach to better understand 

cyanobacterial HABs ecology and the development of 

watershed and source water management techniques, 

including the development of models for nutrients 

loadings, the optimization of watershed placement of 

phosphorus and sediment BMPs, and the use of water 

quality trading (WQT) to cost-effectively reduce 

nutrient loadings. It also includes an assessment of the 

impact of land use and infrastructure on watershed 

changes, and the evaluation of ecological contributors 

to cyanobacterial HAB development and toxin 

production. This research program also includes the 

use of molecular methods to characterize the risk in a 

reservoir for toxin and algal blooms, and the analysis of 

the impact of HABs on creating disinfection by-products 

(DBPs) precursors.
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Program Title

(brief description) Program Activities

EPA EPA HABs Human and 

Ecological Health

Research support to address data gaps associated with 

health, ecosystem, and economic effects of HABs. 

Research activities include the characterization of 

cyanobacteria and their toxins and allergic 

components, the evaluation of the toxicity of multiple 

congeners of microcystins, and identification of 

biomarkers of exposure for human health risk 

assessments. Epidemiology studies to characterize 

toxin occurrence in U.S. inland lakes, and studies to 

determine that bioaccumulation, bioconcentration, 

and biomagnification of cyanotoxins in mammalian 

tissues and food web are also in place. EPA is also 

assessing occurrence and health information for the 

inclusion of cyanotoxins in the Contaminant Candidate 

List (CCL) and the Unregulated Contaminant 

Monitoring Rule (UCMR) program. In addition, EPA is 

developing Human Health Water Quality Criteria

(HHWQC) for cyanotoxins in recreational waters.

EPA EPA HABs

Monitoring and 

Analytical Methods 

Development 

A collaborative effort of EPA, NASA, NOAA, and USGS to 

provide an approach for mainstreaming satellite ocean 

color capabilities into U.S. fresh and brackish water 

quality management decisions. The Cyanobacteria 

Assessment Network (CyAN) for freshwater systems 

will develop approaches to relate nutrient loads and 

land use to the frequency, location, and severity of 

cyanobacterial blooms in lakes of the U.S. It will include 

assessing risk to human health from satellite 

multispectral data to assess biological conditions and 

risk to human health in lakes and reservoirs in the 

United States.

EPA also provides nationally consistent and 

scientifically defensible assessments of aquatic 

resources through the National Aquatic Resource 

Surveys (NARS), including indicators associated with 

cyanotoxin exposure. EPA and its regions are also 

working on monitoring efforts such as the Lake 

Champlain Cyanobacteria Monitoring, Great Lakes 

Restoration Initiative projects and Phosphorus 

Reduction Strategy, Southeast Alaska Tribal Toxins

(SEATT) project, and the Puget Sound Toxins Project.

EPA is also working on monitoring projects to improve 

identification and removal of HAB toxins in drinking 

water, and evaluating the impact of temperature on 

bloom development. 

EPA is developing analytical tools including the use of 

real-time sensors, quantitative polymerase chain 

reaction and fluorescence based technologies of micro 

spectrophotometer and flow cytometry to detect 

cyanobacteria organisms in source water.

EPA EPA HABs Drinking Water 

Treatment

EPA is working collaboratively with regional offices to 

characterize the effectiveness of drinking water 

treatment techniques in reducing toxins. 
68

Office/

Dept. Agency

HABs/

Hypoxia/

Both

Program Title

(brief description) Program Activities

EPA EPA HABs Outreach EPA conducts webinars and provides online resources 

to promote public awareness and information sharing.

NASA NASA HABs

The Ocean Biology 

and Biogeochemistry 

Program

Basic HABs research resulting in publications and new 

retrieval algorithms.

NASA NASA HABs

Health and Air 

Quality Applications 

Program

Improve the forecast resolution and frequency of risk 

of Karenia brevis toxins on every beach, every day, 

rather than every county, twice a week. The methods 

would be applicable across the Gulf of Mexico.

NASA NASA HABs

Health and Air 

Quality Applications 

Program

Monitoring and surveillance of cyanobacterial harmful 

algal blooms in drinking and recreational water 

supplies. Satellite derived products that were 

developed for western Lake Erie are being analyzed for 

their use in other regions (e.g., Chesapeake Bay and 

inland lakes in Ohio and Florida). This project has 

established methods to identify environmental 

thresholds that indicate the potential for 

cyanobacterial blooms to form or persist, and these 

data sets are also being made available to CDC.

Multiple 

agencies and 

partners, 

including but not 

limited to EPA, 

FWS, NOAA, 

NPS, USACE, 

USDA, USGS

HABs and 

hypoxia Water Quality Portal

Co-sponsors of the Water Quality Portal, a cooperative 

data service that makes data publically available. The 

data are derived from the USGS National Water Quality 

Information System (NWIS), the EPA Storage and 

Retrieval data warehouse (STORET), and the USDA ARS 

Sustaining the Earth's Watersheds - Agricultural 

Research Database System (STEWARDS). With data 

from over 400 Federal, state, tribal, and local agencies, 

this efforts will improve understand progress in 

nutrient reduction efforts. 

Multiple 

agencies: CDC, 

NASA, NOAA, 

NSF, USDA, and 

USGS

HABs

Exposure Science 

(ES)21 Federal 

Working Group on 

Exposure Science

Exposure assessment is instrumental in helping to 

forecast, prevent, and mitigate exposure that leads to 

adverse human health or ecological outcomes. This

vision expands exposures from source to dose, over 

time and space, to multiple stressors, and from the 

molecular to ecosystem level. HAB exposure 

assessment is addressed by ES21 Working Groups on 

Biomonitoring, Citizen Engagement/Citizen Science and 

Sensors/Dosimeters.
69

Office/

Dept. Agency

HABs/

Hypoxia/

Both

Program Title

(brief description) Program Activities

Multiple 

Agencies, EPA 

and NOAA

HABS

Volunteer 

Freshwater 

Phytoplankton 

Monitoring Program

Volunteer monitoring program that collects baseline 

data on harmful algal species and builds capacity by 

providing data to NOAA Phytoplankton Monitoring 

Network and EPA. Volunteers are trained to identify 

algae, collect water samples, conduct basic water 

quality analyses, and preserve samples for further 

analysis NOAA Analytical Response Team. Network 

became operational in 2015 with stations in the 

Western Basin of Lake Erie in seven lakes in EPA Region 

8 with plans to expand to Lakes Michigan, Superior, 

Huron and Grand Lake St. Mary in 2016.

USDA

USDA/Multiple 

agencies, led by 

USDA NRCS, 

ARS, NIFA, FSA, 

and NASS. Also 

includes USGS, 

NOAA, FWS, 

EPA, BLM, NASA, 

USDA Economic 

Research Service 

and US Forest 

Service

HABs and 

hypoxia CEAP

The Conservation Effects Assessment Project (CEAP) is 

a collaborative, multi-agency effort to quantify the 

environmental effects of conservation practices and 

programs and develop the science base for managing 

the agricultural landscape for environmental quality. 

Project findings are used to guide USDA conservation 

policy and program development, and help 

conservationists, farmers, and ranchers make more 

informed conservation decisions. USGS will incorporate 

conservation data collected by CEAP into their surface 

water quality monitoring. 

The National Cropland Assessment combines 

information from NASS producer surveys and 

conservation practice data as inputs into two models 

[Agricultural Policy EXtender field-scale model and 

Hydrologic Unit Model for the United States/Soil and 

Water Assessment Tool (HUMUS/SWAT) watershed 

model] to estimate the environmental benefits of 

conservation practices and conservation treatment 

needs within major drainage basins of America. These 

include sub-basins of the Mississippi River Basin, 

Chesapeake Bay and Great Lakes. In addition, the 

Watershed Assessment Component of CEAP conducts 

small watershed scale studies across the United States

to quantify water and soil resource outcomes of 

conservation practices and systems and enhance 

understanding of processes. Interactions among 

practices are investigated as well as modeling 

enhancements, watershed targeting approaches, and 

socioeconomic factors. Practice standards are 

developed or updated to improve effectiveness and 

address gaps.

USDA

Multiple 

agencies, led by 

USDA NRCS, 

ARS, NASS and 

FSA

HABs and 

hypoxia CEAP

In 2012, NASS worked with NRCS to administer a CEAP 

Cropland-survey focused on the Western Lake Erie 

Basin. Data from the survey and other sources is being 

used to assess conservation effects in the Western Lake 

Erie Basin and compare trends and progress in 

conservation as well as evaluate additional treatment 

needs in that region. The assessment report is 

forthcoming.
70

Appendix 4

Actions Taken Since 2008 HABHRCA Reports – HABs

Recommendation 

Categories

2008 HABHRCA 

Recommendations Actions Taken Agencies

Research Effective prevention, 

control, and 

mitigation requires 

an understanding of 

the factors 

contributing to HAB 

events and 

knowledge of their 

impacts on 

ecosystems, wildlife, 

livestock, and 

humans 

Determine causes and impacts of HABs EPA, FDA, 

FWS, NIEHS, 

National 

Institute of 

Standards 

and 

Technology 

(NIST), NSF, 

NOAA, 

USDA, USGS

Prevention Modification of 

nutrient inputs

Ongoing EPA, USACE, 

USDA

Modification of 

hydrodynamic 

conditions

Ongoing

USACE

Minimize or prevent 

introductions of 

invasive HAB species, 

their cysts, and 

organisms that 

facilitate the success 

of HAB species

Ongoing EPA, NOAA

Control Eliminate or reduce 

the levels of HAB 

organisms and their 

toxins

Evaluate various options for destroying and/or removing HAB 

cells and toxins with physical, chemical, or biological methods by 

environmentally and socially acceptable means

EPA, NOAA, 

USDA

Mitigation Improve monitoring 

of HAB cells and 

toxins

1) Develop sensitive, quantitative, field deployable assays and 

sensors for HAB cells, toxins, and relevant toxin metabolites. 

2) Develop remote sensing capabilities for HABs that can be 

utilized in monitoring and management programs. 

3) Integrate HAB and toxin detection technologies into emerging 

U.S. and global ocean observation systems.

EPA, FDA, 

NASA, 

NIEHS, NIST,

NOAA, NSF, 

USACE, USGS
71

Recommendation 

Categories

2008 HABHRCA 

Recommendations Actions Taken Agencies

Facilitate disease 

surveillance, clinical 

characterization, and 

therapeutic guidance 

in humans and 

animals

1) Develop and validate biomonitoring methods of toxin exposure 

and identify and utilize biomarkers for toxin exposure effect and 

disease status.

2) Enhance disease surveillance for human and animal illnesses 

and deaths resulting from HAB toxin exposure by supporting 

existing surveillance systems. 3) Produce clinical therapeutic 

guidance for the spectrum of illnesses associated with exposure 

to HAB cells and toxins. 

4) Develop case definitions for the spectrum of illnesses resulting 

from exposure to HAB cells and toxins.

5) Develop communication and outreach programs to make 

information on HAB poisoning syndromes available to the 

medical and veterinary community in a timely manner.

CDC, EPA, 

FDA, FWS, 

NIEHS, 

NOAA, 

USDA, USGS

Improve drinking 

water monitoring 

and treatment

1) Establish guidelines for safe levels of HAB toxins in drinking and 

recreational water. 

2) Monitor source water for HAB cells and toxins, and develop 

real-time monitoring systems for toxins and cell fragments during 

water treatment. 

3) Develop supplemental water treatment processes for toxins.

EPA, NOAA, 

USGS

Provide HAB 

forecasts from days 

to months in advance 

of HAB events in 

order to provide 

managers, industry, 

and the public with 

early warning

1) Develop predictive models that can forecast HABs in a costeffective and timely manner.

2) Develop food-web based models for the fate and effects of 

HAB toxins. 

3) Develop models of socioeconomic costs of HAB impacts and 

the cost effectiveness of PCM strategies to support decisionmakers.

EPA, NASA, 

NOAA, NSF

Mitigate HAB 

impacts on 

aquaculture and 

wild-capture fishery 

resources 

NOAA

Minimize harvesting 

bans and closures

1) Develop effective risk communication to improve public safety. 

2) Develop and support strategies to minimize closure areas due 

to HAB toxin accumulation.

NOAA, FDA

Modify fishing and 

processing practices 

to protect public 

health

1) Establish toxin loads in different tissue compartments for 

commercially harvestable resources and their impacts on the 

nature of saleable products (e.g., roe-on scallops).

2) Evaluate processing methods that reduce toxin concentrations 

to below regulatory action levels.

3) Facilitate the application of new sampling and analysis 

strategies that would provide access to currently restricted 

resources (e.g., dockside testing protocols for resources on 

Georges Bank, Geoduck harvest in Alaska).

FDA, NOAA, 

USDA

Improve education 

and outreach

Develop an understanding of public knowledge, attitudes, and 

perceptions of HABs, and use that understanding or produce 

effective communication messages for education/outreach 

programs.

EPA, FDA, 

NOAA, 

USDA, USGS

Community 

responses to social 

and economic 

impacts 

Assess and build community resilience to maintain social and 

economic benefits during HABs.

CDC, NOAA
72

Recommendation 

Categories

2008 HABHRCA 

Recommendations Actions Taken Agencies

Intervene to reduce 

wildlife mortality 

NOAA

Understand the 

Human Dimensions 

of HAB events in 

order the assess the 

efficacy of PCM

1) Assess the social and economic impacts of HABs 

2) Measure the social and economic costs and benefits of PCM 

strategies to inform societal decision-making.

3) Develop an understanding of public knowledge, attitudes, and 

perceptions of PCM to produce communication strategies that 

promote public trust, awareness, and risk-reducing behaviors.

4) Identify and evaluate approaches (e.g., economic incentives, 

laws, and education) for facilitating changes in human 

behaviors/attitudes needed to develop and implement PCM 

strategies. 

5) Conduct “institutional analysis” (i.e., research on the nature, 

strengths, and weaknesses of how people work together) to 

improve the coordination of researchers, decision-makers, and 

stakeholders involved in PCM research and implementation

CDC, EPA, 

NOAA, 

USDA, USGS

Event Response Assist during 

outbreaks of new or 

unusual HAB events

1) Provide state and local entities with HAB and toxin testing 

capabilities and assistance with public outreach during a HAB.

2) Maintain (and deploy as needed) a capability for monitoring 

and response of HABs that cause unusual events, like seabird, 

marine mammal mortalities, severely discolored water 

CDC, EPA, 

FDA, FWS, 

NOAA

Infrastructure Provide the services 

and facilities needed 

to understand and 

respond to HAB 

events

Monitoring, training, analytical support during HAB events, data 

management, toxin standards, tissue bank, algal cultures, HAB 

forecasting, and information bulletins.

NOAA, EPA, 

USGS, NIST, 

NSF, FDA, 

USDA
73

Appendix 5

Actions Taken Since 2008 HABHRCA Reports – Hypoxia

Recommendation 

Categories

2008 HABHRCA 

Recommendations Actions Taken Agencies

Prevention and 

Mitigation

Nutrient 

management 

technology 

development and 

improve natural 

nutrient removal 

processes

1) Breed plants cultivars that require less phosphorus fertilizers;

2) Minimize unregulated nutrient loading to freshwater systems 

(NSF Environmental Engineering and Environmental Sustainability 

Program);

3) Optimize watershed placement of phosphorus and sediment 

BMPs;

4) Study changes in land use and infrastructure that inform 

decisions on watershed alterations.

USDA, NSF

Improve 

characterization and 

quantification of 

hypoxia via surveys

1) Measure dissolved oxygen in the water column and sediments. BOEM, 

USGS, 

NOAA, NSF, 

EPA, USGS

Improve 

characterization and 

quantification of 

hypoxia via 

instrumented 

observing systems

1) Collect environmental data with instrumented observing 

systems (e.g. Integrated Ocean Observing System (IOOS) Regional 

Associations; NSF Ocean Observing Initiative, National Ecological 

Observatory Network, Division of Ocean Sciences, and Biological 

Infrastructure).

NSF, NOAA

Improve 

characterization and 

quantification of 

hypoxia via other 

advanced 

technologies (e.g., 

gliders)

1) Map hypoxia using gliders in several coastal regions, including 

Gulf of Mexico (NGOMEX) program support);

2) Develop a comprehensive plan to incorporate gliders into a 

global observation network, and to improve data management,

product development, and data/product delivery (IOOS National 

Glider Network Plan).

NOAA, NSF, 

ONR

Monitor nutrient 

sources and fluxes to 

coastal and 

freshwater systems

1) Tracks and reports the sources and quantities of nutrients 

delivered by streams and groundwater to the Great Lakes, 

freshwater systems, and the Nation’s estuaries; 

2) Pioneers new field sensor methods and systems for monitoring 

and delivering real-time nutrient data needed to address hypoxia 

issues in freshwaters across the Nation.

NOAA, 

USDA, 

USGS

Quantify nutrient flux 

to coastal waters by 

assessing nutrient 

processes in 

watersheds

1) Provide model and decision support tools for managing 

nutrient delivery to evaluate the potential benefits of nutrient 

management (e.g. USGS SPARROW, USDA APEX and Soil and 

Water Assessment Tool/Hydrologic Unit Modeling for the United 

States), NOAA Runoff Risk Advisory Forecast);

2) Quantify the environmental effects of conservation practices 

and programs and develop the science base for managing the 

agricultural landscape for environmental quality (Conservation 

Effects Assessment Project).

EPA, 

FWS,NASA, 

NOAA, 

USDA USGS
74

Recommendation 

Categories

2008 HABHRCA 

Recommendations Actions Taken Agencies

Assess the 

biogeochemical 

pathways that 

process and recycle 

nutrients and carbon 

and ultimately lead 

to generation and 

maintenance of 

hypoxia.

1) Assessment, including statistical, to quantify the relationship 

between nutrient loading, water column primary production, 

water column and benthic respiration, and hypoxia;

2) Quantify the relationship between physical processes (local 

wind strength, wind duration, river discharge volume, water 

column stratification) and hypoxia magnitude (onset, duration, 

areal extent, volume);

3) Assess water column and benthic nutrient transformation 

processes controlling hypoxia. 

EPA, NOAA, 

Naval 

Research 

Lab (NRL), 

NSF, USGS

Evaluate 

effectiveness of 

nutrient reduction 

strategies in reducing 

hypoxia, and 

implement nutrient 

reduction BMPs

1) Support forecast models to assess the progress of nutrient 

reduction actions in mitigating hypoxia, and inform managers of 

the predicted effectiveness of alternative nutrient abatement 

strategies. Hypoxia forecast models in demonstration phase have

been developed for the Gulf of Mexico, Narragansett Bay, 

Chesapeake Bay, Green Bay, and Lake Erie (NOAA NGOMEX and 

CHRP);

2) Quantify the environmental effects of conservation practices 

on spatial and temporal trends in water quality at the small 

watershed scale and develop the science base for managing 

agricultural landscapes for environmental quality (CEAP);

3) Estimate the environmental benefits of conservation practices 

and programs on cropland in large river basins and sub-basins 

and evaluate conservation treatment needs for remaining soil 

and water concerns (CEAP); 

4) Provide a forum for state water, natural resources, and 

agricultural agencies and Federal agencies to

partner on local, state, and regional nutrient reduction efforts, 

encouraging an approach that

takes into account upstream sources and downstream impacts 

(Mississippi River/Gulf of Mexico Watershed Nutrient Task Force);

5) Create an integrated framework that supports planning, 

design, configuration, and delivery of conservation practices 

within the watershed (Mississippi River Basin/Gulf Hypoxia 

Initiative);

6) Monitor water chemistry (e.g., National Estuary Program).

EPA, FWS, 

NASA, 

NOAA, 

USACE, 

USDA, 

USGS

Conduct surveys to 

improve 

characterization of 

hypoxia impacts

1) Monitor inter-annual estimates of relative abundance for 

demersal species occurring in the Gulf of Mexico (NOAA 

SEAMAP);

2) Assess the effects of hypoxia on fish and shrimp distributions in 

coastal systems (NOAA NGOMEX and CHRP).

NOAA

Assess local habitat 

quality with regard to 

water quality 

concerns associated 

with the presence of 

hypoxia 

Assess the effects of hypoxia on fish and shrimp distributions in 

coastal systems (NOAA NGOMEX and CHRP).

NOAA

Quantify the 

ecosystem impacts of 

hypoxia 

Assess the effects of hypoxia on mortality of managed species 

and their prey, fecundity (sublethal effects of exposure), habitat 

and habitat quality, growth (including size), susceptibility to 

predation, migratory patterns, and bycatch (NOAA NGOMEX and 

CHRP).

NOAA
75

Recommendation 

Categories

2008 HABHRCA 

Recommendations Actions Taken Agencies

Assess local water 

quality concerns 

associated with the 

presence of hypoxia 

(e.g., high nitrate in 

drinking water)

Measure dissolved oxygen and provide warnings to drinking 

water managers about hypoxic water near the water intake 

(NOAA Hypoxia Warning System for Cleveland, Ohio).

NOAA

Improve 

characterization and 

quantification of 

hypoxia ecosystem 

impacts via improved 

modeling

Develop ecological models to predict the impacts of hypoxia on 

living resources at the population, community, and ecosystem 

levels (NOAA NGOMEX and CHRP). Advances have been used to 

inform the 2013 reassessment of the Gulf of Mexico Hypoxia Task 

Force Action Plan. 

NOAA

Quantify nutrient flux 

to coastal waters and 

provide decision 

support tools by 

modeling source 

areas, source 

mechanisms, and 

trends in nutrient 

loads

1) Model the linkage between discharge and nutrients from the 

Mississippi River Basin to Gulf of Mexico hypoxia;

2) Create screening-level TMDL models for nitrogen and 

phosphorus.

EPA, NOAA, 

NRL, USGS

Improve existing and 

future coordination 

for data 

management, 

monitoring, and 

research capabilities

EPA, NOAA, 

USDA, 

USGS

Assess economic 

impacts of hypoxia

Assess the bioeconomic effects of hypoxia on shrimp in the Gulf 

of Mexico (NGOMEX program) and the Neuse estuary (CHRP 

program).

NOAA

Biofuels research

Outreach and 

education

Outreach on hypoxia causes and impacts, nutrient reduction 

needs, and BMPs

EPA, FWS, 

NPS, NASA, 

NOAA, 

USACE, 

USDA, 

USGS
76

References

Aikman, F., D.C. Brady, M.J. Brush, P. Burke, C.F. Cerco, J.J. Fitzpatrick, R. He, G.A. Jacobs, W.M. Kemp, 

and J.D. Wiggert. 2014. “Modeling Approaches for Scenario Forecasts for Gulf of Mexico Hypoxia.” 

Edited by D.M. Kidwell, A.J. Lewitus, and E. Turner. White Paper from the Hypoxic Zone Modeling 

Technical Review. Silver Spring, Maryland: NOAA/NOS/NCCOS. 2014. 

http://www2.coastalscience.noaa.gov/publications/detail.aspx?resource=WZFA6NrZ8oBLUl7HzHZ

eLey7RjDGXfagONIXrpHdEEk.

Allen, A.L., C.W. Brown, A.J. Lewitus, P.A. Sandifer. “The Roles of Emerging Technology and Modeling 

Techniques in Operational Ecological Forecasting at NOAA.” Marine Technology Society Journal

49(2/2015): 193-203. DOI: http://dx.doi.org/10.4031/MTSJ.49.2.18.

Anderson, D.M., A.D. Cembella, G. M. Hallegraeff. “Progress in Understanding Harmful Algal Blooms:

Paradigm Shifts and New Technologies for Research, Monitoring, and Management.” Annual 

Reviews of Marine Science 2012 (4): 143-176. DOI: 10.1146/annurev-marine-120308-081121.

Backer, L. “Impacts of Florida Red Tides on Coastal Communities.” Harmful Algae 8(4/2009): 618-622. 

DOI: 10.1016/j.hal.2008.11.008.

Baden, S.P., L.O. Loo, L. Pihl, and R. Rosenberg. “Effects of Eutrophication on Benthic Communities 

Including Fish – Swedish West Coast.” Ambio 19(1990): 113-122. 

http://www.jstor.org.proxy.lib.umich.edu/stable/4313676.

Baganz, D., G. Staaks, and C. Steinberg. “Impact of the Cyanobacteria Toxin, Microcystin-lr, on Behaviour 

of Zebrafish, Danio rerio.” Water Research 32(1998): 948-952. DOI: 10.1016/S0043-

1354(97)00207-8.

Bates, S.S., C.J. Bird, A.S.W. de Freitas, R. Foxall, M. Gilgan, L.A. Hanic, G.R. Johnson, A.W. McCulloch, P. 

Odense, R. Pocklington, M.A. Quilliam, P.G. Sim, J.C. Smith, D.V. Subba Rao, E.C.D. Todd, J.A. 

Walter, and J.L.C. Wright. “Pennate Diatom Nitzschia pungens as the Primary Source of Domoic 

Acid, a Toxin in Shellfish from Eastern Prince Edward Island, Canada.” Canadian Journal of Fisheries 

and Aquatic Sciences 46(1989): 1203-1215. DOI: 10.1139/f89-156.

Beaver, J.R., E.E. Manis, K.A. Loftin, J.L. Graham, A. I. Pollard, R.M. Mitchel. “Land Use Patterns, 

Ecoregion, and Microcystin Relationships in US Lakes and Reservoirs: A Preliminary Evaluation.” 

Harmful Algae 36 (2014): 57-62. DOI: 10.1016/j.hal.2014.03.005.

Boesch, D.F., V.J. Coles, D.G. Kimmel, and W.D. Miller. “Coastal Dead Zones and Global Climate Change: 

Ramifications of Climate Change for the Chesapeake Bay”. In: Regional Impacts of Climate Change: 

Four Case Studies in the United States. Arlington, VA: Pew Center for Global Climate Change. 2007. 

http://www.c2es.org/docUploads/Regional-Impacts-Chesapeake.pdf.

Boyd, C.E. “Dissolved Oxygen and Other Gases.” In Boyd, C.E., Water Quality: An Introduction 2. Springer 

International Publishing. 2015. DOI: 10.1007/978-3-319-17446-4.

Breitburg, D.L. “Effects of Hypoxia, and the Balance between Hypoxia and Enrichment, on Coastal Fishes 

and Fisheries.” Estuaries 25(2002): 767-781. 

http://moritz.botany.ut.ee/~olli/eutrsem/Breitburg02.pdf.

Breitburg, D.L, L. Pihl, and S.E. Kolesar. “Effects of Low Dissolved Oxygen on the Behavior, Ecology and 

Harvest of Fishes: A Comparison of the Chesapeake and Baltic Systems.” In Rabalais, N.N. and R.E. 

Turner (eds.), Coastal Hypoxia: Consequences for Living Resources and Ecosystems. Coastal and 

Estuarine Studies 58. Washington, DC: American Geophysical Union. 2001. DOI: 

10.1029/CE058p0241.
77

Bresnan, E., K. Davidson, M. Edwards, L. Fernand, R. Gowen, A. Hall, K. Kennington, A. McKinney, S. 

Milligan, R. Raine, and J. Silke. “Impacts of climate change on harmful algal blooms.” Marine 

Climate Change Impacts Partnership: Science Review 4(2013): 1-8. DOI: 10.14465/2013.arc24.236-

243.

Bricker, S., C. Clement, D. Pirhalla, S. Orlando, and D. Farrow. National Estuarine Eutrophication 

Assessment. Effects of Nutrient Enrichment in the Nation’s Estuaries. Silver Spring, Maryland: 

NOAA, National Ocean Service, Special Projects Office and National Centers for Coastal Ocean 

Science. 1999. http://specialprojects.nos.noaa.gov/projects/cads/ nees/Eutro_Report.pdf. 

Bricker, S.B., D. Lipton, A. Mason, M. Dionne, D. Keeley, C. Krahforst, J. Latimer, and J. Pennock. 

“Improving Methods and Indicators for Evaluating Coastal Water Eutrophication: A Pilot Study in 

the Gulf of Maine.” NOAA Technical Report 20. Silver Spring, Maryland: National Centers for 

Coastal Ocean Science, Center for Coastal Monitoring and Assessment. 2006. 

http://ccma.nos.noaa.gov/news/feature/GulfofMaine.html.

Bricker, S., B. Longstaff, W. Dennison , A. Jones, K. Boicourt, C. Wicks, and J. Woerner. “Effects of 

Nutrient Enrichment in the Nation’s Estuaries: A Decade of Change, National Estuarine 

Eutrophication Assessment Update.” NOAA Coastal Ocean Program Decision Analysis Series No. 

26. Silver Spring, Maryland: National Centers for Coastal Ocean Science. 2007. 

http://ccma.nos.noaa.gov/news/feature/Eutroupdate.html.

Bricker, S.B., B. Longstaff, W. Dennison, A. Jones, K. Boicourt, C. Wicks, and J. Woerner. “Effects of 

Nutrient Enrichment in the Nation’s Estuaries: A Decade of Change.” Harmful Algae 8(2008): 21-

32. DOI:10.1016/j.hal.2008.08.028.

Bridgeman, T.B., D.W. Schloesser, and A.E. Krause. “Recruitment of Hexagenia Mayfly Nymphs in 

Western Lake Erie Linked to Environmental Variability.” Ecological Applications 16(2/2006): 601-

611. http://www.jstor.org/stable/40061680.

Bridgeman, T.B. and W.A. Penamon. “Lyngbya wollei in Western Lake Erie.” Journal of Great Lakes 

Research 36(1/2010): 167-171. DOI:10.1016/j.jglr.2009.12.003.

Burns, N.M., D.C. Rockwell, P.E. Bertram, D.M. Dolan, and J.J.H.Ciborowski. “Trends in Temperature, 

Secchi Depth, and Dissolved Oxygen Depletion Rates in the Central Basin of Lake Erie, 1983-2002.” 

Journal of Great Lakes Research 31 (Supplement 2/2005): 35-49. DOI: 10.1016/S0380-

1330(05)70303-8.

Caron, D.A., M.-E. Garneau, E. Seubert, M.D.A. Howard, L. Darjany, A. Schnetzera, I. Cetinic ́, G. Filteauc, 

P. Laurid, B. Jonesa, S. Trusselle. “Harmful Algae and their Potential Impacts on Desalination 

Operations off Southern California.” Water Research 44(2/2010): 385-

416.DOI:10.1016/j.watres.2009.06.051.

Carpenter, S.R., S.G. Fisher, N.B. Grimm, and J.F. Kitchell. 1992. “Global Change and Freshwater 

Ecosystems.” Annual Review of Ecology and Systematics 23(1992): 119-139. DOI: 

10.1146/annurev.es.23.110192.001003.

Chaffin, J. D., T. B. Bridgeman, and D. L. Bade. “Nitrogen Constrains the Growth of Late Summer 

Cyanobacterial Blooms in Lake Erie.” Advances in Microbiology 3(2013): 16-26.

DOI: 10.4236/aim.2013.36A003.

Chakraborty, S. and U. Feudel. “Harmful Algal Blooms: Combining Excitability and Competition.” 

Theoretical Ecology 7(2014): 221-237. DOI: 10.1007/s12080-014-0212-1.
78

Chan, F., J.A. Barth, J. Lubchenco, A. Kirincich, H. Weeks, W.T. Peterson, and B.A. Menge. “Emergence of 

Anoxia in the California Current Large Marine Ecosystem.” Science 319(2008): 920. DOI: 

10.1126/science.1149016.

Chorus, I. Current Approaches to Cyanotoxin Risk Assessment, Risk Management and Regulations in 

Different Countries. Dessau-Rosslau, Germany: Federal Environment Agency (Umweltbundesamt). 

2012. http://www.uba.de/uba-info-medien-e/4390.html. 

Committee on Environment and Natural Resources (CENR). Integrated Assessment of Hypoxia in the 

Northern Gulf of Mexico. Washington, DC: National Science and Technology Council Committee on 

Environment and Natural Resources. 2000.

http://oceanservice.noaa.gov/products/hypox_final.pdf. 

Committee on Environment and Natural Resources (CENR). Scientific Assessment of Hypoxia in US 

Coastal Waters. Washington, DC: Interagency Working Group on Harmful Algal Blooms, Hypoxia, 

and Human Health of the Joint Subcommittee on Ocean Science and Technology. 2010. 

https://www.whitehouse.gov/sites/default/files/microsites/ostp/hypoxia-report.pdf. Last 

accessed: June 3, 2015.

Conroy, J. D., D.D. Kane, D.M. Dolan, W.J. Edwards, M.N. Charlton, and D.A. Culver. "Temporal Trends in 

Lake Erie Plankton Biomass: Roles of External Phosphorus Loading and Dreissenid Mussels." 

Journal of Great Lakes Research 31(2005): 89-110. DOI:10.1016/S0380-1330(05)70307-5.

Correll, D.L. “The Role of Phosphorus in Eutrophication of Receiving Waters: A Review”. Journal of 

Environmental Quality 27(1998): 261-266. http://nature.berkeley.edu/classes/espm120/Website/correll1998.pdf.

Craig, J.K. and S.H. Bosman. “Small Spatial Scale Variation in Fish Assemblage Structure in the Vicinity of 

Northwestern Gulf of Mexico Hypoxic Zone.” Estuaries and Coasts 36(2013): 268-285. DOI: 

10.1007/s12237-012-9577-9.

Craig, J.K., and L.B. Crowder. “Hypoxia-Induced Habitat Shifts and Energetic Consequences in Atlantic 

Croaker and Brown Shrimp on the Gulf of Mexico Shelf.” Marine Ecology Progress Series

294(2005): 79-94. DOI: 10.3354/meps294079.

Craig, J.K., L.B. Crowder, and T.A. Henwood. “Spatial Distribution of Brown Shrimp (Farfantepenaeus 

aztecus) on the Northwestern Gulf of Mexico Shelf: Effects of Abundance and Hypoxia.” Canadian 

Journal of Fisheries and Aquatic Sciences 62(2005): 1295-1308. DOI: 10.1139/f05-036.

Craig, J.K. “Aggregation on the Edge: Effects of Hypoxia Avoidance on the Spatial Distribution of Brown 

Shrimp and Demersal Fishes in the Northern Gulf of Mexico.” Marine Ecological Progress Series

445 (2012): 75-95. http://www.int-res.com/abstracts/meps/v445/p75-95/.

Davidson, K., R.J. Gowen, P.J. Harrison, L.E. Flemming, P. Hoagland, G. Moschonas. “Anthropogenic 

Nutrients and Harmful Algae in Coastal Waters.” Journal of Environmental Management.

146(2014): 206-216. DOI: 10.1016/j.jenvman.2014.07.002.

Davis, T.W, D.L. Berry, G.L. Boyer, and C.J. Gobler. “The Effects of Temperature and Nutrients on the 

Growth and Dynamics of Toxic and Non-toxic Strains of Microcystis During Cyanobacteria Blooms.” 

Harmful Algae 8(2009): 715-725. DOI: 10.1016/j.hal.2009.02.004.

Davis, T. W., M. J. Harke, M. A. Marcoval, J. Goleski, C. Orano-Dawson, D. L. Berry, C. J. Gobler. “Effects 

of Nitrogenous Compounds and Phosphorus on the Growth of Toxic and Non-Toxic Strains of 

Microcystis During Cyanobacterial Blooms.” Aquatic Microbial Ecology 61(2010): 149-162.

DOI: 10.3354/ame01445.
79

de Mutsert, K., J.H. Cowan, Jr., and C.J. Walters. “Using Ecopath with Ecosim to Explore Nekton 

Community Response to Freshwater Diversion into a Louisiana Estuary.” Marine and Coastal 

Fisheries: Dynamics, Management, and Ecosystem Science 4(1/2012): 104-116. DOI:

10.1080/19425120.2012.672366.

Deeds, J.R., K. Wiles, G.B. Heideman 6th, K.D. White, A. Abraham. “First U.S. Report of Shellfish 

Harvesting Closures Due to Confirmed Okadaic Acid in Texas Gulf Coast Oysters.” Toxicon

55(2010): 1138-1146. DOI: 10.1016/j.toxicon.2010.01.003.

Delegrange, A., D. Vincent, L. Courcot, R. Amara. “Testing the Vulnerability of Juvenile Sea Bass 

(Dicentrarchus labrax) Exposed to the Harmful Algal Bloom (HAB) Species Pseudo-nitzschia 

delicatissima.” Aquaculture 437 (2015): 167-174. DOI: 10.1016/j.aquaculture.2014.11.023.

Delorme, L. D. “Lake Erie Oxygen: The Prehistoric Record.” Canadian Journal of Fisheries and Aquatic 

Sciences 39(1982): 1021–1029. DOI: 10.1139/f82-137.

Diaz, R.J. and R. Rosenberg. “Marine Benthic Hypoxia: A Review of its Ecological Effects and the 

Behavioural Responses of Benthic Macrofauna.” Oceanography and Marine Biology an Annual 

Review 33(1995): 245-303. 

http://www.researchgate.net/profile/Robert_Diaz5/publication/236628341_Marine_benthic_hyp

oxia_A_review_of_its_ecological_effects_and_the_behavioural_responses_of_benthic_macrofaun

a/links/02e7e526a7c717396d000000.pdf.

Diaz, R.J. and R. Rosenberg. “Spreading Dead Zones and Consequences for Marine Ecosystems.” Science

321(2008): 926-929. DOI: 10.1126/science.1156401.

Diaz, R.J. and R. Rosenberg. “Introduction to Environmental and Economic Consequences of Hypoxia.” 

International Journal of Water Resources Development 27(2011): 71-82. DOI: 

10.1080/07900627.2010.531379.

Dortch, Q., D.M. Anderson, D.L. Ayres, and P.M. Glibert. Harmful Algal Bloom Research, Development, 

Demonstration and Technology Transfer: A National Workshop Report. Woods Hole, 

Massachusetts: Woods Hole Oceanographic Institute. 2008.

http://www.whoi.edu/fileserver.do?id=43464&pt=10&p=19132. 

Dyson, K., D. D. Huppert. “Regional Economic Impacts of Razor Clam Beach Closures Due to Harmful 

Algal Blooms (HABs) on the Pacific Coast of Washington.” Harmful Algae 9(2010): 264-271. 

doi:10.1016/j.hal.2009.11.003.

Dziuban, E.J., J.L. Liang, G.F. Craun, V. Hill, P.A. Yu, J. Painter, M.R. Moore, R.L. Calderon, S.L. Roy, and 

M.J. Beach. “Surveillance for Waterborne Disease and Outbreaks Associated with Recreational 

Water – United States, 2003-2004.” Morbidity and Mortality Weekly Report Surveillance 

Summaries 55(2006): 1-30. http://www.cdc.gov/mmwr/PDF/ss/ss5512.pdf. 

Ecological Society of America. “The Role Of Atmospheric Deposition In The Gulf Of Mexico Hypoxic Zone: 

Workshop Report.” http://www.esa.org/esa/science/reports/hypoxia/. Last accessed: June 5, 

2015.

Etheridge, S. “Paralytic Shellfish Poisoning: Seafood Safety and Human Health Perspectives.” Toxicon 56 

(2010/2): 108-122. DOI: 10.1016/j.toxicon.2009.12.013.

Francesconi, W., Smith, D.R., Heathman, G.C., Wang, X., Williams, C. “Monitoring and APEX modeling of 

no-till and reduced-till in tile drained agricultural landscapes for water quality.” Transactions of the 

ASABE 57(3/2014):777-789. 

http://www.researchgate.net/profile/Wendy_Francesconi/publication/264120739_MONITORING_

AND_APEX_MODELING_OF_NO-TILL_AND_REDUCED-TILL_IN_TILE-
80

DRAINED_AGRICULTURAL_LANDSCAPES_FOR_WATER_QUALITY/links/53cec9da0cf2f7e53cf7d1dc.

pdf.

Fujiki, H. and M. Suganuma. “Tumor Promoters-Microcystin-LR, Nodularin and TNF-α and Human Cancer 

Development.” Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal ChemistryAnti-Cancer Agents) 11.1(2011): 4-18. DOI: 10.2174/187152011794941163.

Genitsaris, S., K.A. Kormas, M. Moustaka-Gouni. “Airborne Algae and Cyanobacteria: Occurrence and 

Related Health Effects.” Frontiers in Bioscience 3(2011): 772-787. 

http://kkormas.users.uth.gr/genitsarisFB.pdf.

Giannuzzi, L., D. Sedan, R. Echenique, and D. Andrinolo. “An Acute Case of Intoxication with 

Cyanobacteria and Cyanotoxins in Recreational Water in Salto Grande Dam, Argentina.” Marine 

Drugs 9(2011): 2164-2175. DOI: 10.3390/md9112164.

Gingold, D., M.J. Strickland, and J.J. Hess. “Ciguatera Fish Poisoning and Climate Change: Analysis of 

National Poison Center Data in the United States, 2001-2011.” Environmental Health Perspectives

122(2014): 580-586. DOI: http://dx.doi.org/10.1289/ehp.1307196.

Graham, J. L., K. A. Loftin, and N. Kamman. “Monitoring Recreational Freshwaters.” Lakeline (2009): 18-

24. http://ks.water.usgs.gov/static_pages/studies/water_quality/cyanobacteria/LLsummergraham2.pdf.

Great Lakes Water Quality Protocol of 2012. Signed September 7, 2012. Entered into force February 12, 

2013. https://www.ec.gc.ca/grandslacs-greatlakes/A1C62826-72BE-40DB-A545-

65AD6FCEAE92/1094_Canada-USA%20GLWQA%20_e.pdf. Last accessed: August 17, 2015.

Greenfield, D.I., A. Duquette, A. Goodson, C.J. Keppler, S.H. Williams, L.M. Brock, K.D. Stackley, D. White, 

and S. Wilde. “The Effects of Three Chemical Algaecides on Cell Numbers and Toxin Content of the 

Cyanobacteria Microcystis aeruginosa and Anabaenopsis sp.” Environmental Management

54(2014): 1110-1120. DOI: 10.1007/s00267-014-0339-2.

Griffis, R., and J. Howard, ed. 2013. Oceans and Marine Resources in a Changing Climate: Technical Input 

to the 2013 National Climate Assessment. Washington, DC: Island Press, 249 pp.

Grimes, D.J., M.T. Hamann, J.M. Lotz, T.I. McLean, T. McIlwain, and C.H. Price. “Oceans and Human 

Health, Social and Economic Impacts.” In: R.A. Meyers (ed.), Encyclopedia of Sustainability Science 

and Technology. New York: Springer 2012. DOI: 10/1007/978-1-4419-0851-3_834.

Gulland, F.M.D. and A.J. Hall. “Is Marine Mammal Health Deteriorating? Trends in the Global Reporting 

of Marine Mammal Disease.” EcoHealth 4(2007): 135-150. DOI: 10.1007/s10393-007-0097-1.

Hamidi, S.A., H.R. Bravo, and J.V. Klump. “Evidence of Multiple Physical Drivers on the Circulation and 

Thermal Regime in the Green Bay of Lake Michigan.” World Environmental and Water Resources 

Congress 2013: Showcasing the Future. (2013): 1719-1726. DOI: 10.1061/9780784412947.169.

HARRNESS. Harmful Algal Research and Response: A National Environmental Science Strategy 2005-

2015. J.S. Ramsdell, D.M. Anderson, and P.M. Glibert (eds.) Washington, DC: Ecological Society of 

America. 2005. http://www.esa.org/HARRNESS/harrnessReport10032005.pdf. 

Hazen, E. L., J. K. Craig, C. P. Good, and L. B. Crowder. “Vertical Distribution of Fish Biomass in Hypoxic 

Waters on the Gulf of Mexico Shelf.” Marine Ecological Progress Series 375(2009): 195-207. DOI: 

10.3354/meps07791.

Hilborn, E.D., V.A. Roberts, L. Backer, E. DeConno, J.S. Egan, J.B. Hyde, D.C. Nicholas, E.J. Wiegert, L.M. 

Billing, M. DiOrio, M.C. Mohr, F.J. Hardy, T.J. Wade, J.S. Yoder, and M.C. Hlavsa. “Algal BloomAssociated Disease Outbreaks Among Users of Freshwater Lakes – United States, 2009-2010.” 
81

Morbidity and Mortality Weekly Report (MMWR) 63(2014): 11-15. 

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6301a3.htm.

Hilborn, E.D., V.R. Beasley. “One Health and Cyanobacteria in Freshwater Systems: Animal Illnesses and 

Deaths Are Sentinel Events for Human Health Risks.” Toxins 7(2015): 1374-1395. 

DOI: 10.3390/toxins7041374.

Hoagland, P. and S. Scatasta. “The Economic Effects of Harmful Algal Blooms.” In: E. Graneli and J.T. 

Turner (eds.), Ecology of Harmful Algae. Berlin, Germany: Springer. 2006. DOI: 10/1007/978-3-540-

32210-8_30. 

Hollister, J.W., W.B Milstead, B.J. Kreakie. “Modeling Lake Trophic State: A Random Forest Approach.” 

(In revision.)

Horst, G.P., O. Sarnelle, J.D. White, S.K. Hamilton, R.B. Kaul, and J.D. Bressie. “Nitrogen Availability 

Increases the Toxin Quota of Harmful Cyanobacterium, Microcystis aeruginosa.” Water Research

54(2014): 188-198. DOI: 10.1016/j.watres.2014.01.063.

Howden, S.D, R.A. Arnone, J. Brodersen, S.F. DiMarco, L.K. Dixon, H.E. Garcia, M.K. Howard, A.E. Jochens, 

S.E. Ladner, C.E. Lembke, A.P. Leonardi, A. Quaid, and N.N. Rabalais. Glider Implementation Plan 

for Hypoxia Monitoring in the Gulf of Mexico. Edited by A.J. Lewitus, S.D. Howden, and D.M. 

Kidwell. National Oceanic and Atmospheric Administration. 2014. 

http://coastalscience.noaa.gov/news/wp-content/uploads/2014/05/Glider-Implementation-Planfor-Hypoxia-Monitoring-in-the-Gulf-of-Mexico.pdf.

Hudnell, H. K., Q. Dortch, and H. Zenick. “An Overview of the Interagency, International Symposium on 

Cyanobacterial Harmful Algal Blooms (ISOC-HAB): Advancing the Scientific Understanding of 

Freshwater Harmful Algal Blooms.” Advances in Experimental Medicine and Biology 619(2008): 1-

16. DOI: 10.1007/978-0-387-75865-7_1. 

Institute of Medicine (US) Committee on Evaluation of the Safety of Fishery Products. “Naturally 

Occurring Fish and Shellfish Poisons.” Ahmed FE, editor. Seafood Safety. Washington (DC): 

National Academies Press (US). 1991(4). http://www.ncbi.nlm.nih.gov/books/NBK235731/. Last 

accessed: May 12, 2015.

Jewett, E.B., C.B. Lopez, Q. Dortch, S.M. Etheridge. “National Assessment of Efforts to Predict and 

Respond to Harmful Algal Blooms in US Waters. Interim Report.” Washington, DC: Interagency 

Working Group on Harmful Algal Blooms, Hypoxia, and Human Health of the Joint Subcommittee 

on Ocean Science and Technology. 2007.

Jewett, E.B., C.B. Lopez, Q. Dortch, S.M. Etheridge, and L.C. Backer. Harmful Algal Bloom Management 

and Response: Assessment and Plan. Washington, DC: Interagency Working Group on Harmful 

Algal Blooms, Hypoxia and Human Health of the Joint Subcommittee on Ocean Science and 

Technology 2008. 

http://www.cop.noaa.gov/stressors/extremeevents/hab/habhrca/HABMngmt_resp_9_08.pdf.

Justic ́, D., V.J. Bierman, Jr., D. Scavia, and R.D. Hetland. “Forecasting Gulf’s Hypoxia: The Next 50 Years?” 

Estuaries and Coasts 30(5/2007): 791-801. http://www.jstor.org/stable/27654716.

Karlson, K., R. Rosenberg, and E. Bonsdorff. “Temporal and Spatial Large-Scale Effects of Eutrophication 

and Oxygen Deficiency on Benthic Fauna in Scandinavian and Baltic Waters: A 

Review.” Oceanography and Marine Biology 40(2002): 427-489. DOI: 10.1.1.177.8144.

Kemp, W.M., W.R. Boynton, J.E. Adolf, D.F. Boesch, W.C. Boicourt, G. Brush, J.C. Cornwell, T. R. Fisher, 

P.M. Gilbert, J.D. Hagy, L.W. Harding, E.D. Houde, D.G. Kimmel, W.D. Miller, R.I. E. Newell, M.R. 

Roman, E.M. Smith, and J.C. Stevenson. “Eutrophication of Chesapeake Bay: Historical Trends and 
82

Ecological Interactions.” Marine Ecology Progress Series 303(2005): 1-29. DOI: 

10.3354/meps303001.

Kraus, R.T., C.T. Knight, T.M. Farmer, A.M. Gorman, P.D. Collingsworth, G.J. Warren, P.M. Kocovsky, and 

J.D. Conroy. “Dynamic Hypoxic Zones in Lake Erie Compress Fish Habitat, Altering Vulnerability to 

Fishing Gears.” Canadian Journal of Fisheries and Aquatic Sciences 72(2015): 1-10. DOI: 

10.1139/cjfas-2014-0517.

Kudela, R.M., E. Berdalet, S. Bernard, M. Burford, L. Fernand, S. Lu, S. Roy, P. Tester, G. Usup, R. 

Magnien, D.M. Anderson, A. Cembella, M. Chinain, G. Hallegraeff, B. Reguera, A. Zingone, H. 

Enevoldsen, E. Urban. A Scientific Summary for Policy Makers. IOC/UNESCO, Paris (IOC/INF-1320). 

http://unesdoc.unesco.org/images/0023/002334/233419e.pdf. Last accessed: August 10, 2015.

Lapointe, B.E., P.J. Barile, W.R. Matzie. “Anthropogenic Nutrient Enrichment of Seagrass and Coral Reef 

Communities in the Lower Florida Keys: Discrimination of Local Versus Regional Nitrogen Sources.” 

Journal of Experimental Marine Biology and Ecology, 308(1/2004). 308:23-58.

Lehane, L. and R.J. Lewis. “Ciguatera: Recent Advances but the Risk Remains.” International Journal of 

Food Microbiology 61(2000): 91-125. DOI: 10.1016/S0168-1605(00)00382-2.

Lewitus, A., R.A. Horner, D.A. Caron, E. Garcia-Mendoza, B.M. Hickey, M. Hunter, D.D. Huppert, R.M. 

Kudela, G.W. Langlois, J.L. Largier, E.J. Lessard, R. RaLonde, J.E. Jack Rensel, P.G. Strutton, V.L. 

Trainer, J.F. Tweddle. “Harmful Algal Blooms Along the North American West Coast Region: 

History, Trends, Causes, and Impacts.” Publications, Agencies and Staff of the US Department of 

Commerce (499/2012). http://digitalcommons.unl.edu/usdeptcommercepub/499.

Lipton, D. W. and R. Hicks. “Linking Water Quality Improvements to Recreational Fishing Values.” In: 

Evaluating the Benefits of Recreational Fisheries. Fisheries Centre Research Reports 7(2/1999). 

University of British Columbia.

Lipton D., and R. Hicks. “The Cost of Stress: Low Dissolved Oxygen and Economic Benefits of Recreational 

Striped Bass (Morone saxatilis) Fishing in the Patuxent River.” Estuaries 26(2003): 310-315. 

http://www.jstor.org/stable/1353127.

Lopez, C. B., E. B. Jewett, Q. Dortch, B. T. Walton, and H. K. Hudnell. Scientific Assessment of Freshwater 

Harmful Algal Blooms. Washington, D.C. : Interagency Working Group on Harmful Algal Blooms, 

Hypoxia, and Human Health of the Joint Subcommittee on Ocean Science and Technology. 2008a. 

https://www.whitehouse.gov/sites/default/files/microsites/ostp/frshh2o0708.pdf.

Lopez, C.B., Q. Dortch, E.B. Jewett, and D. Garrison. Scientific Assessment of Marine Harmful Algal 

Blooms. Washington, DC: Interagency Working Group on Harmful Algal Blooms, Hypoxia, and 

Human Health of the Joint Subcommittee on Ocean Science and Technology. 2008b. 

https://www.whitehouse.gov/sites/default/files/microsites/ostp/jsost-assess_12-08.pdf.

Lunetta, R.S., B.A. Schaeffer, R.P. Stumpf, D. Keith, S.A. Jacobs, M.S. Murphy. “Evaluation of 

cyanobacteria cell count detection derived from MERIS imagery across the eastern USA.” 

Remote Sensing of Environment 157(2015): 24-34. DOI: 10.1016/j.rse.2014.06.008.

Lürling, M. and I. Roessink. “On the Way to Cyanobacterial Blooms: Impact of the Herbicide Metribuzin 

on the Competition between a Green Alga (Scenedesmus) and a Cyanobacterium (Microcystis).” 

Chemosphere 65(4/2006): 618-626. DOI:10.1016/j.chemosphere.2006.01.073.

Marinho, M.M., Souza, M.B.G., Lurling, M. “Light and phosphorous competition between 

Cylindrospermopsis raciborskii and Microcystis aeruginosa is strain dependent.” Microbial Ecology

66(2013): 479-488. DOI: 10.1007/s00248-013-0232-1.
83

Maryland Department of Natural Resources. Eyes on the Bay. 2015. 

http://mddnr.chesapeakebay.net/eyesonthebay/.

McCoy, C., R. Viso, R.N. Peterson, S. Libes, B. Lewis, J. Ledoux, G. Voulgaris, E. Smith, D. Sanger. “Radon 

as an Indicator of Limited Cross-Shelf Mixing of Submarine Groundwater Discharge Along an Open 

Ocean Beach in the South Atlantic Bight During Observed Hypoxia.” Continental Shelf Research

31(2011): 1306-1317. DOI: 10.1016/j.csr.2011.05.009.

McGillicuddy, D.J., Jr., D.M. Anderson, D.R. Lynch, and D.W. Townsend. “Mechanisms Regulating LargeScale Seasonal Fluctuations in Alexandrium fundyense Populations in the Gulf of Maine: Results 

from a Physical-Biological Model.” Deep-Sea Research 52(2005): 2698-2714. 

DOI:10.1016/j.dsr2.2005.06.021.

Mee, L. “An Achievable goal in a new Europe?” In: European Conference on Marine Science and Ocean 

Technology. Luxembourg: Office for Official Publications of the European Communities. 2007. 

http://www.euroceanconferences.eu/attachments/eurocean2004_report_declaration.pdf.

Melillo, J.M., T.C. Richmond, G.W. Yohe, Eds., 2014. Climate Change Impacts in the United States: The 

Third National Climate Assessment. U.S. Global Change Research Program, 841 pp. DOI: 

10/7930/J0Z31WJ2.

Michalak, A.M., E.J. Anderson, D. Beletski, S. Boland, N.S. Bosch, T.B. Bridgeman, J.D. Chaffin, K. Cho, R. 

Confesor, I. Daloglu, J.V. DePinto, M.A. Evans, G.L. Fahnenstiel, L. He, J.C. Ho, L. Jenkins, T.H. 

Johengen, K.C. Kuo, E. LaPorte, X. Liu, M.R. McWilliams, M.R. Moore, D.J. Posselt, R.P. Richards, D. 

Scavia, A.L. Steiner, E. Verhamme, D.M. Wright, and M.A. Zagorski. “Record-Setting Algal Bloom in 

Lake Erie Caused by Agricultural and Meteorological Trends Consistent with Expected Future 

Conditions.” Proceedings of the National Academy of Sciences 110.16 (2013): 6448-6452. DOI: 

10.1073/pnas.1216006110.

Moore, S.K., N.J. Mantua, and E.P. Salathé, Jr. “Past Trends and Future Scenarios for Environmental 

Conditions Favoring the Accumulation of Paralytic Shellfish Toxins in Puget Sound Shellfish.” 

Harmful Algae 10 (2011): 521-529. DOI: 10.1016/j.hal.2011.04.004.

Moore, W. S. “The Effect of Submarine Groundwater Discharge on the Ocean.” Marine Science 2 (2010): 

59-88. DOI: 10.1146/annurev-marine-120308-081019.

Munday, R. “Toxicology of Seafood Toxins: A Critical Review.” In: Botana, L.M. Seafood and Freshwater 

Toxins: Pharmacology, Physiology, and Detection. 2014. ISBN-13: 978-1466505148.

Murphy, T.P., A. Lawson, M. Kumagai, and J. Babin. “Review of Emerging Issues in Sediment Treatment.” 

Aquatic Ecosystem Health and Management 2(1999): 419-434. DOI: 10.1080/14634989908656980.

Murphy, C.A., K.A. Rose, M.S. Rahman, and P. Thomas. “Testing and Applying a Fish Vitellogenesis Model 

to Evaluate Laboratory and Field Biomarkers of Endocrine Disruption in Atlantic Croaker 

(Micropogonias undulates) Exposed to Hypoxia.” Environmental Toxicology and Chemistry

28(6/2009): 1288-1303. DOI: 10.1897/08-304.1.

Najjar, R.G., H.A. Walker, P.J. Anderson, E.J. Barron, R.J. Bord, J.R. Gibson, V.S. Kennedy, C.G. Knight, J.P. 

Megonigal, R.E. O’Connor, C.D. Polsky, N.P. Psuty, B.A. Richards, L.G. Sorenson, E.M. Steele, and 

R.S. Swanson. “The potential Impacts of Climate Change on the Mid-Atlantic Coastal Region.” 

Climate Research 14(2000): 219-233.

http://www.cara.psu.edu/about/publications/Najjar_et_al_2000.pdf.

National Oceanic and Atmospheric Administration (NOAA). “Interim Report on the Bottlenose Dolphin 

(Tursiops truncatus) Unusual Mortality Event Along the Panhandle of Florida, March-April 2004.” 
84

2004. http://www.nmfs.noaa.gov/pr/pdfs/health/ume_bottlenose_2004.pdf. Last accessed: 

January 22, 2016.

National Oceanic and Atmospheric Administration (NOAA). COAST's National Status and Trends, NS&T 

Program Download Page. 2012. http://ccma.nos.noaa.gov/about/coast/nsandt/download.aspx. 

Last accessed: April 29, 2015. 

National Oceanic and Atmospheric Administration (NOAA). “2015 Gulf of Mexico Dead Zone ‘Above 

Average’”. Press release. August 4, 2015. http://www.noaanews.noaa.gov/stories2015/080415-

gulf-of-mexico-dead-zone-above-average.html.

National Research Council, Committee on Human and Environmental Exposure Science in the 21st 

Century; Board on Environmental Studies and Toxicology; Division on Earth and Life Studies. 

Exposure Science in the 21st Century: A Vision and a Strategy. Washington, DC: The National 

Academies Press, 2012. http://www.ncbi.nlm.nih.gov/books/NBK206816/. 

O’Neil, J.M., T.W., Davis, M.A. Burford, and C.J. Gobler. “The Rise of Harmful Cyanobacteria Blooms: The 

Potential Roles of Eutrophication and Climate Change.” Harmful Algae 14(2012): 313-334. DOI: 

10.1016/j.hal.2011.10.027.

Paerl, H.W., and J. Huisman. “Blooms Like it Hot.” Science 320(2008): 57-58. 

DOI: 10.1126/science.1155398.

Paerl, H.W. and V.J. Paul. “Climate Change: Links to Global Expansion of Harmful Cyanobacteria.” Water 

Research. 46(2012): 1349-1363. DOI: doi:10.1016/j.watres.2011.08.002.

Paerl, H.W. and T.G. Otten. “Harmful Cyanobacterial Blooms: Causes, Consequences, and Controls.” 

Microbial Ecology 46(5/2013): 1349-1363. DOI: 10.1007/s00248-012-0159-y.

Pellerin, B.A., B.A. Bergamaschi, R.J. Gilliom, C.G. Crawford, J. Saraceno, C.P. Frederick, B.D. Downing, 

and J.C. Murphy. “Mississippi River Nitrate Loads from High Frequency Sensor Measurements and 

Regression-Based Load Estimation.” Environmental Science & Technology 48(2014): 12612−12619. 

DOI: 10.1021/es504029c.

Peterson, H.G., C. Boutin, K.E. Freemark, and P.A. Martin. “Toxicity of hexazinone and diquat to green 

algae, diatoms, cyanobacteria and duckweed.” Aquatic Toxicology 39(1997): 111-134. 

DOI:10.1016/S0166-445X(97)00022-2.

Pierson, J.J., M.R. Roman, D.G. Kimmel, W.C. Boicourt, and X.Zhang. “Quantifying Changes in Vertical 

Distribution of Mezoplankton in Response to Hypoxic Bottom Waters.” Journal of Experimental 

Marine Biology and Ecology 381(2009): S74-S79. DOI:10.1016/j.jembe.2009.07.013.

Rabalais, N.N. and R.E. Turner. “Coastal Hypoxia: Consequences for Living Resources and Ecosystems.” 

Coastal Estuarine Studies 58. Washington, DC: American Geophysical Union. 2001.

DOI: 10.1029/CE058.

Rabalais, N.N., R.E. Turner, and W.J. Wiseman, Jr. “Hypoxia in the Gulf of Mexico.” Journal of 

Environmental Quality 30(2001):320-329. DOI:10.2134/jeq2001.302320x.

Rabalais, N.N., R.E. Turner, B.K. Gupta, D.F. Boesch, P. Chapman, and M.C. Murrell. “Hypoxia in the 

Northern Gulf of Mexico: Does the Science Support the Plan to Reduce, Mitigate, and Control 

Hypoxia?” Coastal and Estuarine Research Federation 30(5/2007): 753-772.

Rabotyagov, S. S., C.L. Kling, P.W. Gassman, N.N. Rabalais, and R.E. Turner. “The Economics of Dead 

Zones: Causes, Impacts, Policy Changes, and a Model of the Gulf of Mexico Hypoxic Zone.” Review 

of Environmental Economics and Policy 8(1/2014) 58-79. DOI: 10.1093/reep/ret024.
85

Rahman, M.S. and P. Thomas. “Molecular Cloning, Characterization and Expression of Two Tryptophan 

Hydroxylase (TPH-1 and TPH-2) Genes in the Hypothalamus of Atlantic Croaker: Down-Regulation 

after Chronic Exposure to Hypoxia.” Neuroscience 158(2009): 751-765. 

DOI:10.1016/j.neuroscience.2008.10.029.

Rahman, M.S., and P. Thomas. “Characterization of Three IGFBP mRNAs in Atlantic Croaker and their 

Regulation During Hypoxic Stress: Potential Mechanisms of their Upregulation by Hypoxia.” 

American Journal of Physiology Endocrinology and Metabolism 301(4/2011): E637-648. DOI: 

10.1152/ajpendo.00168.2011.

Rahman, M.S., I.A. Khan, and P. Thomas. “Tryptophan Hydroxylase: A Target for Neuroendocrine 

Disruption.” Journal of Toxicology and Environmental Health, Part B: Critical Reviews 14(5-7/2011): 

473-494. DOI: 10.1080/10937404.2011.578563.

Rahman, M.S. and P. Thomas. “Effects of Hypoxia Exposure on Hepatic Cytochrome P450 (CYP1A) 

Expression in Atlantic Croaker: Molecular Mechanisms of CYP1A Down-Regulation.” PLOS One

(7/2012). DOI: 10.1371/journal.pone.0040825.

Ramsdell, J.S. and F.M. Gulland. “Domic Acid Epileptic Disease.” Marine Drugs 12(3/2014): 1185-1207. 

DOI:10.3390/md12031185.

Rief, M.K. “Remote Sensing for Inland Water Quality Monitoring: A US Army Corps of Engineers 

perspective.” US Army Corps of Engineers ERDC/EL TR-11-13. Kiln, Mississippi: Environmental 

Laboratory, Engineer Research and Development Center. 2011. 

http://acwc.sdp.sirsi.net/client/en_US/search/asset/1005263;jsessionid=A3303A1D6663B0C3E80E

E25EAE424A3B.enterprise-15000.

Riegl, B.M., A.W. Bruckner, K. Samimi-Namin, S.J. Purkis. “Diseases, Harmful Algae Blooms (HABs) and 

their Effects on Gulf Coral Populations and Communities.” Coral Reefs of the Gulf, Coral Reefs of 

the World 3(2012): 107-125. Leiden, The Netherlands: Springer Netherlands. 2012. DOI: 

10.1007/978-94-007-3008-3_7.

Ritter, C. and P.A. Montagna. “Seasonal Hypoxia and Models of Benthic Response in a Texas Bay.” 

Estuaries 22(1/1999): 7-20. http://www.jstor.org/stable/1352922.

Roman, M.R., J.J. Pierson, D. G. Kimmel, W.C. Boicourt, and X. Zhang. “Impacts of Hypoxia on 

Zooplankton Spatial Distributions in the Northern Gulf of Mexico.” Estuaries and Coasts 35(2012): 

1261-1269. DOI 10.1007/s12237-012-9531-x.

Rosenblatt, A.E., M.R. Heithaus, M.E. Mather, P. Matich, J. Nifong, W.J. Ripple, and B. Silliman. “The 

roles of Large Top Predators in Coastal Ecosystems: New Insights from Long Term Ecological 

Research.” Oceanography 26(2013): 156-167. DOI: 10.5670/oceanog.2013.59.

Sagasti, A., L.C. Schaffner, and J.E. Duffy. “Effects of Periodic Hypoxia on Mortality, Feeding and 

Predation in an Estuarine Epifaunal Community.” Journal of Experimental Marine Biology and 

Ecology 258(2001): 257-283. DOI: 10.1016/S0022-0981(01)00220-9.

Sanford, W.E. and J.P. Pope. “Quantifying Groundwater’s Role in Delaying Improvements to Chesapeake 

Bay Water Quality.” Environmental Science and Technology 47 (2013/23): . DOI: 

10.1021/es401334k.

Scavia, D. and K.A. Donnelly. “Reassessing Hypoxia Forecasts for the Gulf of Mexico.” Environmental 

Science and Technology 41(2007): 8111-8117. DOI: 10.1021/es0714235.
86

Scavia, D., D. Justić, and V.J. Bierman, Jr. “Reducing Hypoxia in the Gulf of Mexico: Advice from Three 

Models.” Coastal and Estuarine Research Federation 27(3/2004): 419-425. DOI: 

10.1007/BF02803534.

Scavia, D., J.D. Allan, K.K. Arend, S. Bartel, D. Beletsky, N.S. Bosch, S.B. Brandt, R.D. Briland, I. Daloğlu, 

J.V. DePinto, D.M. Dolan , M.A. Evans, T.M. Farmer, D. Goto, H. Han, T.O. Höök, R. Knight , S.A. 

Ludsin, D. Mason, A.M. Michalak, R.P. Richards, J.J. Roberts, D. K. Rucinski, E. Rutherford, D.J. 

Schwab, T.M. Sesterhenn, H. Zhang, Y. Zhou. “Assessing and Addressing the Re-eutrophication of 

Lake Erie: Central Basin Hypoxia.” Journal of Great Lakes Research 40.2 (2014): 226-246. 

DOI:10.1016/j.jglr.2014.02.004.

Schottler, S.P., J. Ulrich, P. Belmont, R. Moore, J.W. Lauer, D.R. Engstrom, and J. E. Almendinger. 

“Twentieth Century Agricultural Drainage Creates More Erosive Rivers.” Hydrological Processes

28(2014): 1951-1961. DOI: 10.1002/hyp.9738.

Seltenrich, N. “Keeping Tabs on HABs: New Tools for Detecting, Monitoring, and Preventing Harmful 

Algal Blooms.” Environmental Health Perspective 122(2014): A206-A213. DOI: 10.1289/ehp.122-

A206.

Shumway, S.E. “A Review of the Effects of Algal Blooms on Shellfish and Aquaculture.” Journal of the 

World Aquaculture Society 21(2/1990): 65-104. DOI: 10.1111/j.1749-7345.1990.tb00529.x.

Simeone, C.A., F.M.D. Gulland, T. Norris, T.K. Rowles. “A Systematic Review of Changes in Marine 

Mammal Health in North America, 1972-2012: The Need for a Novel Integrated Approach.” 

PLoSOne 10(11): e0142105. doi: 10.1371/journal.pone.0142105.

Smith, D.R., King, K.W., Johnson, L., Francesconi, W., Richards, P., Baker, D., Sharpley, A.N. “Surface 

runoff and tile drainage transport of phosphorus in the Midwestern United States.” Journal of 

Environmental Quality 44 (2/2014): 495-502. DOI:10.2134/jeq2014.04.0176.

Smith, D.R., K.W. King, M.R. Williams. “What is Causing the Harmful Algal Blooms in Lake Erie?” Journal 

of Soil and Water Conservation 70(2015): 27A-29A. DOI: 10.2489/jswc.70.2.27A.

Smith, M.D., F. Asche, L.S. Bennear, A. Oglend. “Spatial-Dynamics of Hypoxia and Fisheries: The Case of 

Gulf of Mexico Brown Shrimp.” Marine Resources Economics 29(2014): 111-131. DOI: 

http://dx.doi.org/10.1086/676826.

Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor, and H.L. Miller. “Climate 

Change 2007: The physical science basis,” Contribution of Working Group I to the Fourth 

Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University 

Press, New York. 2007.

Stow, C.A. and T. Hook, Eds., with D. Beletsky, R. Beletsky, A. Burtner, J.H. Bredin, J. Cavaletto, Y. Cha, C. 

De Marchi, J.V. DePinto, J. Dyble, D.Fanslow, S. Francoeur, D. Gossiaux, N. Hawley, C. He, T.H. 

Johengen, D.R. Kashian, M.D. Kaplowitz, W. Keiper, P.J. Lavrentyev, F. Lupi, D.F. Millie, N. 

Morehead, T.F. Nalepa, T.J. Newcomb, D. Palladino, S.D. Peacor, S.A. Pothoven, T. Redder, M. 

Selzer, H.A. Vanderploeg, E. Verhamme, K.Winslow. 2013. “Saginaw Bay Management Report.” 

NOAA Technical Memorandum GLERL 160. Ann Arbor, Michigan: NOAA, Great Lakes 

Environmental Research Laboratory. 2013. 

http://www.glerl.noaa.gov/ftp/publications/tech_reports/glerl-160/tm-160.pdf. Last accessed: 

May 15, 2015.
87

Stumpf, R.P., M.C. Tomlinson, J.A. Calkins, B. Kirkpatrick, K. Fisher, K. Nierenberg, R. Currier, and T.T. 

Wynne. “Skill Assessment for an Operational Algal Bloom Forecast System.” Journal of Marine 

Systems 76(1-2/2009): 151-161. DOI: 10.1016/j.jmarsys.2008.05.016.

Svirčev, Z., S. Krstic, M. Miladinov-Mikov, V. Baltic, M. Vidovic. “Freshwater Cyanobacterial Blooms and 

Primary Liver Cancer Epidemiological Studies in Serbia.” Journal of Environmental Science and 

Health, Part C: Environmental Carcinogenesis and Ecotoxicology Reviews 27(1/2009): 36-55. DOI: 

10.1080/10590500802668016. 

Taylor, M., L. McIntyre, M. Ritson, J. Stone, R. Bronson, O. Bitzikos, W. Rourke, E. Galanis, Outbreak 

Investigation Team. “Outbreak of Diarrhetic Shellfish Poisoning Associated with Mussels, British 

Columbia, Canada.” Marine Drugs 11(2013): 1669-1676. DOI: 10.3390/md11051669.

Thomas, P., and M.S. Rahman. “Chronic Hypoxia Impairs Gamete Maturation in Atlantic Croaker Induced 

by Progestins through Nongenomic Mechanisms Resulting in Reduced Reproductive Success.” 

Environmental Science & Technology 43(11/2009a): 4175-4180. DOI: 10.1021/es9000399.

Thomas, P., and S.M. Rahman. “Biomarkers of Hypoxia Exposure and Reproductive Function in Atlantic 

Croaker: A Review with Some Preliminary Findings from the Northern Gulf of Mexico Hypoxic 

Zone.” Journal of Experimental Marine Biology and Ecology 381 (Suppl./2009b): S38-S50. 

doi:10.1016/j.jembe.2009.07.008

Thomas, P. and M.S. Rahman. “Region-Wide Impairment of Atlantic Croaker Testicular Development and 

Sperm Production in the Northern Gulf of Mexico Hypoxic Dead Zone.” Marine Environmental 

Research 69(2010): 559-562. DOI:10.1016/j.marenvres.2009.10.017

Thomas, R. and M.S. Rahman. “Extensive Reproductive Disruption, Ovarian Masculinization and 

Aromatase Suppression in Atlantic Croaker in the Northern Gulf of Mexico Hypoxic Zone.”

Proceedings of the Royal Society B 279(2011): 19–27. DOI: 10.1098/rspb.2011.0529

Thomas, P., M.S. Rahman, I.A. Khan, and J.A. Kummer. “Widespread Endocrine Disruption and 

Reproductive Impairment in an Estuarine Fish Population Exposed to Seasonal Hypoxia.” 

Proceedings of the Royal Society B 274(2007): 2693-2701. DOI:10.1098/rspb.2007.0921.

Thronson, A. and A. Quigg. 2008. “Fifty-Five Years of Fish Kills in Coastal Texas.” Coastal and Estuarine 

Research Federation 31(4/2008): 802-813. DOI 10.1007/sl2237-008-9056-5.

Thurston, R. V. Fish Physiology, Toxicology, and Water Quality Proceedings of the Sixth International 

Symposium. La Paz, B.C.S. Mexico: Ecosystems Research Division. 2002. 

Tian, D., W. Zheng, X. Wei, X. Sun, L. Liu, X. Chen, H. Zhang, Y. Zhou, H. Chen, H. Zhang, Q. Wang, R. 

Zhang, S. Jiang, Y. Zheng, G. Yang, and W. Qu. “Dissolved Microcystins in a Surface and Ground 

Waters in Regions with High Cancer Incidence in the Huai River Basin of China.” Chemosphere 

91(2013): 1064-1071. DOI:10.1016/j.chemosphere.2013.01.051.

Toledo-Lucas County Health Department. “Community Assessment for Public Health Emergency Response

(CASPER) Following Detection of Microcystin Toxin in a Municipal Water Supply, Lucas County, Ohio.”

https://www.odh.ohio.gov/~/media/ODH/ASSETS/Files/eh/OHCASPERReport. Last accessed: January 8, 2016.

Tomer, M.D., S.A. Porter, K.M. Boomer, D.E. James, J.A. Kostel, M.J. Helmers, T.M. Isenhart, and E. 

McLellan. “Agricultural Conservation Planning Framework: Developing Multipractice Watershed 

Planning Scenarios and Assessing Nutrient Reduction Potential.” Journal of Environmental Quality

44(2015): 754-767. DOI:10.2134/jeq2014.09.0386.
88

Trainer, V. L., L. Moore, B.D. Bill, N.G. Adams, N. Harrington, J. Borchert, D.A.M. da Silva, B.-T. L. 

Eberhart. “Diarrhetic Shellfish Toxins and Other Lipophilic Toxins of Human Health Concern in 

Washington State.” Marine Drugs 11(2013): 1815-1835. DOI: 10.3390/md11061815.

Trainer, V.L., and F.J Hardy. “Integrative monitoring of marine and freshwater harmful algae in 

Washington State for public health protection.” Toxins 7(2015): 1206-1234. 

DOI:10.3390/toxins7041206.

Turner, P.C., A.J. Gammie, K. Hollinrake, and G.A. Codd. “Pneumonia Associated with Contact with 

Cyanobacteria.” British Medical Journal 300(1990): 1440-1441. DOI: 10.1136/bmj.300.6737.1440.

United States Department of Agriculture Natural Resources Conservation Service (USDA NRCS). 

Assessment of the effects of conservation practices on cultivated cropland in the Great Lakes 

Region. 2011. http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1045480.pdf. Last 

accessed: May 15, 2015.

United States Environmental Protection Agency (EPA). Hypoxia in the Northern Gulf of Mexico. An 

Update by the EPA Science Advisory Board. Washington, DC: EPA Science Advisory Board. 2007. 

www.epa.gov/sab. Last accessed May 12, 2015.

United States Environmental Protection Agency (EPA). Reactive Nitrogen in the United States: An 

Analysis of Inputs, Flows, Consequences, and Management Options. Washington, DC: EPA Science 

Advisory Board. 2011. 

http://yosemite.epa.gov/sab/sabproduct.nsf/02ad90b136fc21ef85256eba00436459/67057225CC

780623852578F10059533D/$File/EPA-SAB-11-013-unsigned.pdf. Last accessed June 3, 2015.

United States Environmental Protection Agency (EPA). “National Coastal Condition Assessment (NCCA).” 

2014. http://water.epa.gov/type/oceb/assessmonitor/ncca.cfm, Last accessed: April 29, 2015.

United States Environmental Protection Agency (EPA 2015a). A Compilation of Cost Data Associated with 

the Impacts and Control of Nutrient Pollution. EPA 820-F-15-096.2015.

http://www2.epa.gov/sites/production/files/2015-04/documents/nutrient-economics-report2015.pdf. Last accessed: May 15, 2015. 

United States Environmental Protection Agency (EPA 2015b). “Drinking Water Health Advisory for the 

Cyanobacterial Microcystin Toxins.” EPA-820R15100. 

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0

ahUKEwibp_WhhKLKAhUFdj4KHdrHBhoQFggcMAA&url=http%3A%2F%2Fwww.epa.gov%2Fsites%

2Fproduction%2Ffiles%2F2015-06%2Fdocuments%2Fmicrocystins-report2015.pdf&usg=AFQjCNE8s_eYfa1IhwJ-FyUnH-m525bK0A&bvm=bv.111396085,d.cWw. Last 

accessed: January 11, 2016.

United States Environmental Protection Agency (EPA 2015c). “Strategy Submitted to Congress to Meet 

the Requirements of P.L. 114-45.” EPA-810R04003. 

http://www.epa.gov/sites/production/files/2015-11/documents/algal-risk-assessment-strategicplan-2015.pdf. Last accessed: January 13, 2016.

United States Geological Survey (USGS). 2002.

United States Geological Survey (USGS). “WaterQualityWatch – Continuous Real-Time Water Quality of 

Surface Water in the United States.” 2014.http://waterwatch.usgs.gov/wqwatch/?pcode=00630.

Last accessed: April 29, 2015.

United States Geological Survey (USGS). “National Water Information System: Web Interface, USGS 

07374000 Mississippi River at Baton Rouge, LA.” 2015. 

http://waterdata.usgs.gov/nwis/uv?site_no=07374000. Last accessed: April 29, 2015. 
89

van der Schalie, W.H., H.S. Gardner, Jr, J.A. Bantle, C.T. De Rosa, R.A. Finch, J.S. Reif, R.H. Reuter, L.C. 

Backer, J. Burger, L.C. Folmar, and W.S. Stokes. “Animals as Sentinels of Human Health Hazards of 

Environmental Chemicals.” Environmental Health Perspectives 107(1999): 309-315.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1566523/pdf/envhper00509-0101.pdf.

Vanderploeg. H.A., J.R. Liebig, W.W. Carmichael, M.A. Agy, T.H. Johengen, G.L. Fahnenstiel, and T.F. 

Nalepa. “Zebra Mussel (Dreisssena polymorpha) Selective Filtration Promoted Toxic Microcystis 

Blooms in Saginaw Bay (Lake Huron) and Lake Erie.” Canadian Journal of Fisheries and Aquatic 

Sciences 58(2001): 1208-1221. DOI: 10.1139/cjfas-58-6-1208.

Vaquer-Sunyer, R. and C.M. Duarte. “Thresholds of Hypoxia for Marine Biodiversity.” Proceedings of the 

National Academy of Sciences 105(40/2008): 15452–15457DOI: 10.1073pnas.0803833105.

Vitousek, P.M., J.D. Aber, R.W. Howarth, G.E. Likens, P.A. Matson, D.W. Schindler, W.H. Schlesinger, and 

D.G. Tilman. “Human Alteration of the Global Nitrogen Cycle: Sources and Consequences.” 

Ecological Applications 7(3/1997): 737-750. http://biol336-

bowen.wikispaces.umb.edu/file/view/Vitousek+et+al.+1997.pdf.

Wells, M.L., V.L. Trainer, T.J. Smayda, B.S. O. Karlson, C.G. Trick, R.M. Kudela, A. Ishikawa, S. Bernard, A. 

Wulff, D.M. Anderson, W.P. Cochlan. In press. “Harmful Algal Blooms (HABs) and Climate Change:

What do We Know and Where do We Go from Here?” Harmful Algae 49(2015). 

DOI:10.1016/j.hal.2015.07.009.

Westrick, J.A. “Cyanobacterial Toxin Removal in Drinking Water Treatment Processes and Recreational 

Waters.” In Cyanobacterial Harmful Algal Blooms: State of the Science and Research Needs. New 

York: Springer. 2008. DOI: 10.1007/978-0-387-75865-7_13.

White, M.J., C. Santhi, N. Kannan, J.G. Arnold, D. Harmel, L. Norfleet, P. Allen, M. DiLuzio, X. Wang, J. 

Atwood, E. Haney, and M.V. Johnson. “Nutrient Delivery from the Mississippi River to the Gulf of 

Mexico and Effects of Cropland Conservation.” Soil and Water Conservation Society 69(1/2014): 

26-40. DOI: 10.2489/jswc.69.1.26.

Whitledge T.E. “Nationwide Review of Oxygen Depletion and Eutrophication in Estuarine and Coastal 

Waters. Executive Summary.” Report to U.S. Dept. of Commerce, NOAA. Upton, New York: 

Oceanographic Sciences Division, Brookhaven National Laboratory. 1985.

http://oceanservice.noaa.gov/websites/retiredsites/sotc_pdf/HYP.PDF.

Wilson, E. K. “Danger from Microcystins in Toledo Drinking Water Unclear.” Chemical Engineering 

News, 92(32/2014). http://cen.acs.org/articles/92/i32/Danger-Microcystins-Toledo-WaterUnclear.html.

World Health Organization . Guidelines for Drinking-Water Quality: Incorporating 1st and 2nd Addenda, 

Vol.1, Recommendations. 3rd ed. Geneva, Swtizerland: WHO. 2008. 

http://www.who.int/water_sanitation_health/dwq/fulltext.pdf.

Wynne, T.T., R.P. Stumpf, M.C. Tomlinson, G.L.Fahnenstiel, J. Dyble, D.J. Schwab, S.J. Joshi. “Evolution of 

a Cyanobacterial Bloom Forecast System in Western Lake Erie: Development and Initial 

Evaluation.” Journal of Great Lakes Research 39(2013): pp. 90-99. DOI: 

10.1016/j.jglr.2012.10.003.

Yoder, J.S., B.G. Blackburn, G.F. Craun, V. Hill, D.A. Levy, N. Chen, S.H. Lee, R.L. Calderon, and M.J. Beach. 

“Surveillance for Waterborne-Disease Outbreaks Associated with Recreational Water – United 

States, 2001-2002.” Mobidity and Mortality Weekly Report Surveillance Summaries 53(2004): 1-22. 

http://www.cdc.gov/mmwr/PDF/ss/ss5308.pdf.
90

Zhang, Y.-K. and K.E.Schilling. “Increasing Streamflow and Baseflow in Mississippi River since 1940s: 

Effect of Land Use Change.” Journal of Hydrology 324 (2006): 412-422. DOI: 

10.1016/j.jhydrol.2005.09.033.
91

Abbreviations

ALS Amyotrophic Lateral Sclerosis (Lou Gehrig’s Disease)

APEX Agricultural Policy/Environmental eXtender

ARS Agricultural Research Service (USDA)

ART Analytical Response Team (NOAA)

ASP Amnesic Shellfish Poisoning

BMAA Beta-methylamine Alanine

BMP Best management practice

CASPER Community Assessment for Public Health Emergency Response

CCL Contaminant Candidate List

CDC Centers for Disease Control and Prevention

CEAP Conservation Effects Assessment Project (USDA and others)

CFR Code of Federal Regulations

CFP Ciguatera Fish Poisoning

CHRP Coastal Hypoxia Research Program 

CRM Certified Reference Materials

CWA Clean Water Act

DHHS Department of Health and Human Services

DOC Department of Commerce

DOD Department of Defense

DOI Department of the Interior

DSP Diarrhetic Shellfish Poisoning

ECOHAB The Ecology and Oceanography of Harmful Algal Blooms program 

authorized by the Harmful Algal Bloom and Hypoxia Research and 

Control Act Centers for Disease Control and Prevention (1998, 2014)

EPA United States Environmental Protection Agency

EQIP Environmental Quality Incentives Program

FDA Food and Drug Administration

GLRI Great Lakes Restoration Initiative

GLOS Great Lakes Observing System

HABs Harmful Algal Blooms

HABHRCA Harmful Algal Bloom and Hypoxia Research and Control 

Amendments Act of 2014
92

IOOS Integrated Ocean Observing System

IWG-HABHRCA Interagency Working Group on the Harmful Algal Bloom and 

Hypoxia Research and Control Act

LEOFS Lake Erie Operational Forecast System

NASS National Agricultural Statistics Service (USDA)

NASA National Aeronautics and Space Administration

NCCOS National Centers for Coastal Ocean Science (NOAA)

NCER National Center for Environmental Research (EPA)

NGOMEX Northern Gulf of Mexico Ecosystems and Hypoxia Assessment

NIEHS National Institute of Environmental Health Sciences

NIFA National Institute of Food and Agriculture (USDA)

NIST National Institute of Standards and Technology

NOAA National Oceanic and Atmospheric Administration

NORS National Outbreak Reporting System

NPS National Park Service

NRCS Natural Resources Conservation Service (USDA)

NRL Naval Research Lab

NSF National Science Foundation

NSTC National Science and Technology Council

OSTP Office of Science and Technology Policy

PCM Prevention, Control, and Mitigation

PCMHAB Program that transitions promising PCM technologies and strategies 

to end-users and is authorized by the Harmful Algal Bloom and 

Hypoxia Research and Control Act (1998, 2014)

PMN Phytoplankton Monitoring Network

PSP Paralytic Shellfish Poisoning 

RCPP Regional Conservation Partnership Program

SPARROW SPAtially-Referenced Regression on Watershed attributes model

SOST Subcommittee on Ocean Science and Technology

SDWA Safe Drinking Water Act

USACE United States Army Corps of Engineers

USDA United States Department of Agriculture

USGS United States Geological Survey

WHO World Health Organization
93

Glossary of Terms

Aerosolization – The process or act of converting some physical substance into the form of particles small 

and light enough to be carried on the air, i.e. into an aerosol.

Algae – Simple plant-like, photosynthetic organisms that form the base of most aquatic food webs, 

ranging from microscopic, single-celled diatoms, dinoflagellates, and cyanobacteria, to large seaweeds. 

Aquatic – Of, in, or pertaining to marine and fresh waters, including the Great Lakes, and concentrates 

herein on those in the US and its territories.

Benthic – Ecological region at the lowest level of a body of marine or fresh water such as an ocean or a 

lake, including the sediment surface and sub-surface layers.

Best Management Practices – A method by which the adverse impacts of development and 

redevelopment are controlled through their application.

Carnivorous – Meat-eating animal.

Clean Water Act – This act establishes the basic structure for regulating discharges of pollutants into the 

waters of the United States and regulating quality standards for surface waters (1948, 1972).

Cyanobacteria – Photosynthetic bacteria that frequently form harmful algal blooms in marine and fresh 

waters; also called blue-green algae.

Cyanotoxin – Toxins produced by cyanobacteria.

Dissolved oxygen – The amount of gaseous oxygen present in the water.

Drinking Water Protection Act – An amendment to the Safe Drinking Water Act to provide for the 

assessment and management of the risk of algal toxins in drinking water, and for other purposes.

Ecosystem services – A benefit that an ecosystem provides to people.

Estuarine systems (Estuaries) – Systems that receive freshwater inputs from rivers, and that mix with 

ocean water.

Eutrophication – The enrichment of an ecosystem with chemical nutrients; typically compounds 

containing nitrogen, phosphorus, or both.

Farm Bill – The Agricultural Act of 2014; a five-year farm bill that reforms agricultural policy, reduces the 

deficit, and grows the economy.

Food web – Also known as a food chain. The visual depiction of relationships between living things, what 

they feed on, and what feeds on them. For example: Little fish eat algae. Bigger fish eat the little fish. 

Humans eat the bigger fish.

Freshwater – Naturally-occurring water on the Earth's surface in ice sheets, ice caps, glaciers, icebergs, 

bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground 

streams. Freshwater salinity is less than 0.5 g/kg.

Halocline – A vertical gradient of the salinity (saltiness) of a body of water.

Harmful algal blooms (HABs) – A small subset of algal species – including diatom, dinoflagellate, and 

cyanobacterial blooms – that produce toxins or grow excessively, harming humans, other animals, and 

the environment.

Herbivorous – Plant-eating animal.
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Hypoxia – In reference to this report, waters that are, or have been, severely depleted of oxygen.

Hypoxic events – When a body of water experiences a deficiency of oxygen. 

In situ – In the normal location. 

Nonpoint source – Pollution of a non-specific origin that is introduced into a body of water from land 

runoff, precipitation, atmospheric deposition, drainage, seepage, or hydrologic modification.

Nuisance algal blooms – Excessive algal/cyanobacterial growth that can promote pathogens and cause 

detrimental effects like hypoxia, but that do not produce toxins. 

Plankton – Diverse assemblage of organisms that live in the water column and cannot swim against a 

current.

Phytoplankton – Minute plant-like organisms and other photosynthetic organisms – including 

cyanobacteria, diatoms, and dinoflagellates – that live in water and cannot swim against a current.

Phytoplankton bloom – Rapid increase or accumulation in the population of microscopic algae in a water 

body.

Point source pollution – Pollutant loads discharged at a specific location from pipes, outfalls, and 

conveyance channels from factories, confined animal feedlots, municipal wastewater treatment plants or 

individual waste treatment facilities.

Public Health Security and Bioterrorism Preparedness and Response Act – 2002 law that requires 

community drinking water systems serving populations of more than 3,300 persons to conduct 

assessments of their vulnerabilities to terrorist attack or other intentional acts, and to defend against 

adversarial actions that might substantially disrupt the ability of a system to provide a safe and reliable 

supply of drinking water. The EPA and water utilities are responsible for enhancing water sector security 

and developing response measures for potential threats to the nation's water supplies and systems.

Research Plan and Action Strategy – First report mandated by HABHRCA 2014. The Comprehensive HAB 

and Hypoxia Research Plan and Action Strategy will report on challenges related to HABs and hypoxia, 

ongoing and planned research, and the agencies’ roles and responsibilities for evaluating and managing 

these issues.

Riparian Buffer Line – Trees, shrubs, or other vegetation lining the banks of a waterway that stabilize the 

ground, preventing erosion.

Safe Drinking Water Act – Originally passed in 1974, the main Federal law that ensures the quality of 

Americans' drinking water. Under SDWA, EPA sets standards for drinking water quality and oversees the 

states, localities, and water suppliers who implement those standards.

Salinity – Dissolved salt content of a body of water expressed as grams salt per kilogram of water.

Stratification – Segregation of the water column into distinct layers due to density differences that occur 

when the surface layer is warmer or has a lower salt content than the underlying water.

Thermocline – A vertical gradient of temperature. Water temperatures typically decline with depth, but 

often not uniformly. A thermocline is the depth at which small changes in depth lead to relatively large 
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changes in temperature. The greater the temperature change across the thermocline, the more stable 

and distinct the upper layer of water.

Upwell/upwelling – The process by which warm, less-dense surface water is drawn away from along a 

shore by offshore currents and replaced by cold, denser water brought up from the subsurface.