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EXHIBIT 21 (AR L.30)

The National Ocean Service: Working for America’s Coasts

More information or access to data, products, and services can be obtained from our Web sites:

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The National Ocean Service (NOS) approaches the 21st century with a clear vision–that our coasts and oceansenjoy robust health, provide a rich bounty of resources, and are wisely managed to endure competing uses. Asthe nation's principal advocate for coastal and ocean stewardship, the National Ocean Service develops thenational foundation for coastal and ocean science, management, response, restoration, and navigation. Thisreport, developed by the NOS Special Projects Office and the National Centers for Coastal Ocean Science, strength-ens this foundation, helping to bridge the gap between science, management, and public policy.

The Special Projects Office works to increase the effectiveness of coastal management in the United States, therebyensuring continued economic prosperity and environmental well-being throughout the nation's coastal regions.A main objective of the Special Projects Office is to provide expertise, products, and services that assist the NOSin designing and implementing an effective program of coastal stewardship throughout the agency. This effortincludes exploring ways to leverage the agency's considerable expertise into a force that more directly supportsand influences the sound management and protection of coastal areas. Special Projects is in a unique position tobridge the gap between NOS scientific efforts and coastal management policy issues.

The National Centers for Coastal Ocean Science (NCCOS) works to understand the ocean and coastal environ-ment, and the influences of human activities, by conducting research, monitoring, and assessments of thesedelicate and important areas. NCCOS activities include understanding and predicting impacts of pollution andcoastal development on sensitive habitats and resources; helping to protect coastal property and residents fromstorms and other natural hazards; understanding the causes and consequences of harmful algal blooms, such asred tides and toxic Pfiesteria piscicida; understanding how climate change may affect our lives; and determiningthe complex factors that affect fish populations.

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1305 East-West Highway, 9th FloorSilver Spring, MD 20910-3281

This report should be cited as: Bricker, S.B., C.G. Clement, D.E. Pirhalla, S.P. Orlando, and D.R.G. Farrow. 1999.National Estuarine Eutrophication Assessment: Effects of Nutrient Enrichment in the Nation’s Estuaries. NOAA,National Ocean Service, Special Projects Office and the National Centers for Coastal Ocean Science. Silver Spring,MD: 71 pp.


National Estuarine Eutrophication Assessment

Effects of Nutrient Enrichment in the Nation’s Estuaries

Special Projects Officeand the

National Centers for Coastal Ocean Science

National Ocean ServiceNational Oceanic and Atmospheric Administration

1305 East-West HighwaySilver Spring, MD 20910

September 1999

Suzanne B. Bricker, Christopher G. Clement, Douglas E. Pirhalla, S. Paul Orlando, Daniel R.G. Farrow

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Richard Alexander U.S. Geological SurveyWalter Boynton University of MarylandDavid Brock Texas Water Development BoardDarell Brown U.S. Environmental Protection AgencyDavid Chestnut South Carolina Department of Health and Environmental ControlDavid Flemer U.S. Environmental Protection AgencyHolly Greening Tampa Bay National Estuary ProgramThomas Malone University of MarylandGregory McMurray Oregon Department of Environmental QualityJan Newton Washington Department of EcologyJonathan Pennock University of Alabama/Dauphin Island Sea LabAndrew Robertson National Oceanic and Atmospheric AdministrationDonald Stanley East Carolina UniversityJ. Kevin Summers U.S. Environmental Protection AgencyTerry Whitledge University of Alaska

National Assessment Core Group

National Assessment Workshop ParticipantsMerryl Alber University of GeorgiaDonald Boesch University of MarylandThomas Brosnan National Oceanic and Atmospheric AdministrationBrian Cole U.S. Geological SurveyElizabeth Cosper Cosper Environmental Services, Inc.Christopher D’Elia State University of New York at AlbanyErnest Estevez Mote Marine LaboratoryPeggy Fong University of CaliforniaFred Holland South Carolina Department of Wildlife and Marine ResourcesRenee Karrh Maryland Department of Natural ResourcesJack Kelly U.S. Environmental Protection AgencyPeter Larsen Bigelow Laboratory for Ocean ScienceTheodore Loder University of New HampshireRobert Magnien Maryland Department of Natural ResourcesMichael Mallin University of North CarolinaHank McKellar University of South CarolinaGary Powell Texas Water Development BoardRandy Shuman Metropolitan King County, WashingtonRichard Smith U.S. Geological SurveyRonald Thom Battelle Marine Science LaboratoryDavid Tomasko Southwest Florida Water Management DistrictRichard Valigura National Oceanic and Atmospheric AdministrationPeter Verity Skidaway Institute of OceanographyRichard Wetzel Virginia Institute of Marine Science

We would like to thank all of the estuarine research scientists and coastal resource managers whose contribu-tions of data, information, and expertise were the key to making this report possible (Appendix C). The CoreGroup was instrumental in developing methods for aggregating the data and, along with the other participantsin the National Assessment Workshop, reviewed and analyzed the results and made recommendations for anational-level response to eutrophication problems in the nation’s estuaries.

This report is the result of the dedication and cooperation of many individuals who remained committed dur-ing the long duration of the project. Special thanks go to Daniel J. Basta, Director of NOS Special Projects, for hisvision and unflagging support, and to Richard Alexander and Richard Smith of the U.S. Geological Survey foruse of their SPARROW model results prior to publication. We also thank our NOS colleagues Charles Alexanderand C. John Klein for technical advice; Alison Hammer, John Hayes, Percy Pacheco, and Scot Frew for invalu-able support provided for the National Assessment Workshop; Denise Yver for designing the report cover; andPam Rubin for reviewing and editing the manuscript.

ii

Acknowledgments


Foreword.......................................................................................................................... ivExecutive Summary ........................................................................................................ vEutrophication Diagram ............................................................................................... ix

Introduction ..................................................................................................................... 1Estuarine Eutrophication: Background to the Problem ....................................................... 1The Nation’s First Comprehensive Estuarine Eutrophication Assessment ...................... 3The National Report: A Challenge to Interpret the Data ..................................................... 3Extending the Assessment: Toward a National Strategy ..................................................... 6Organizing the Results: Seven Key Questions ...................................................................... 8Using this Report and the Data ............................................................................................... 8

National Overview ......................................................................................................... 9Eutrophic Conditions ................................................................................................................ 9Completing the Picture ........................................................................................................... 13

Regional Summaries .................................................................................................... 19North Atlantic .......................................................................................................................... 20Middle Atlantic ........................................................................................................................ 24South Atlantic ........................................................................................................................... 28Gulf of Mexico.......................................................................................................................... 32Pacific ........................................................................................................................................ 36

Conclusions.................................................................................................................... 41

Toward A National Strategy ....................................................................................... 45

Data Sources .................................................................................................................. 47

AppendicesA. Methods ................................................................................................................... 49B. Table of Results ......................................................................................................... 63C. Participants ............................................................................................................... 67

iii

Table of Contents


Nancy Foster, Ph.D.Assistant Administrator for Ocean Services

and Coastal Zone ManagementNational Ocean Service, NOAA

This report is the culmination of almost seven years of effort to assess compre-hensively the scale, scope, and characteristics of nutrient enrichment andeutrophic conditions in the nation’s estuaries. It provides the most compre-hensive assessment of this issue ever assembled for our nation’s estuaries,and the results represent a significant contribution to the development of anational strategy to control nutrient enrichment problems affecting U.S. coastalwaters. With this information, we have the opportunity to make a real differ-ence in the actions this nation takes to address this important issue.

These results provide a valuable context for a host of ongoing and plannedactivities addressing estuarine eutrophication, including reauthorization ofthe Coastal Zone Management Act, particularly section 6217; reauthorizationof the Clean Water Act; the states’ development of Unified Watershed Assess-ments and Watershed Restoration Priorities as part of the Clean Water ActionPlan; the Report on the Status of the Nation’s Ecosystems; the Committee onEnvironment and Natural Resources Gulf of Mexico Hypoxia Study; andNOAA’s National Dialogues on Coastal Stewardship.

As important as the results themselves is the process used to acquire this in-formation. The approach explicitly recognized that much of what is knownabout these problems resides within the knowledge and experience of expertsaround the nation. Hence, a process was developed to systematically obtaininformation from more than 300 experts on estuarine eutrophication. Thoseinterested in this innovative approach to information synthesis can review theAppendices to learn more about these methods and how to apply them.

During the past year, the National Ocean Service (NOS) has undergone a reor-ganization, and is emerging with a new focus on coastal stewardship. One ofthe new roles for NOS is as a catalyst to ensure that scientific results are tar-geted to providing solutions to environmental problems and to preservingthe nation’s coastal and ocean resources. This report is also an example of thetype of activity that is needed to better bridge the gap between scientists andresource managers. I encourage you to use this work to stimulate further ef-forts to protect our natural resources.

iv

Foreword


Eutrophication is the accelerated productionof organic matter, particularly algae, in a wa-ter body. It is usually caused by an increasein the amount of nutrients being dischargedto the water body. As a result of acceleratedalgal production, a variety of impacts mayoccur, including nuisance and toxic algalblooms, depleted dissolved oxygen, and lossof submerged aquatic vegetation. These im-pacts are interrelated and usually viewed ashaving a negative effect on water quality andecosystem health. Eutrophication has beenrecognized as a problem in freshwater sys-tems for many years, but only in the pastthree decades has concern grown about thewidespread occurrence of eutrophic condi-tions in estuarine systems. Due to the com-plexity of the phenomena and the lack ofconsistent national data sets, the severity andextent of the problem had never been ad-equately characterized at the national scale.

What are the severity and extent ofeutrophic conditions exhibited withinthe estuaries of the United States?

To what extent are eutrophic conditionsin the nation’s estuaries caused by hu-man activities?

To what extent do eutrophic conditionsimpair the use of estuarine resources,and what are the important impaireduses?

Where should management efforts betargeted to achieve the greatest benefittoward remediation and protection fromdegradation?

v

The National AssessmentThis report presents the results of a NationalAssessment Workshop held in August 1998to address the problem of estuarineeutrophication. The assessment was basedprimarily on the results of the National Es-tuarine Eutrophication Survey, conductedby NOAA from 1992 to 1997, but wassupplemented by information on nutrientinputs, population projections, and land usedrawn from a variety of sources. It covers138 estuaries, representing over 90 percentof the estuarine surface area of the cotermi-nous United States, plus the MississippiRiver Plume. The final assessment pre-sented here was undertaken at the NationalAssessment Workshop by a select group ofexperts, all of whom participated in theeutrophication survey. The Workshop wasstructured around answering seven keyquestions regarding the severity and extentof eutrophication in the nation’s estuaries.All results presented in this report were re-viewed by the Workshop participants.

About Estuarine Eutrophication

To what extent can the severity and ex-tent of eutrophic conditions be expectedto increase by the year 2020, given thenatural susceptibility of estuaries and thepotential for increasing nutrient inputs?

Which data gaps and research and moni-toring needs are most critical in terms ofimproving the ability to assess and re-spond to eutrophication symptoms?

How can the results of this assessmentbe translated into a national strategy?

1.

2.

3.

4.

5.

6.

7.

Key Questions

Executive Summary


vi

Executive Summary

Eutrophication Severity and Extent

Human Influence on Eutrophication

High expressions of eutrophic conditions are ex-hibited in 44 estuaries, representing 40% of thetotal estuarine surface area studied. An additional40 estuaries exhibit moderate conditions. Whenconsidered together, the estuaries with moderateto high conditions represent 65% of estuarine sur-face area in the study.

High conditions occur in estuaries along all coasts,but are most prevalent in estuaries along the Gulfof Mexico and Middle Atlantic coasts.

82 estuaries, representing 67% of estuarine sur-face area, exhibit moderate to high expressions ofat least one of the following symptoms: depleteddissolved oxygen, loss of submerged vegetation,and nuisance/toxic algal blooms.

A high level of human influence is associated witha majority (36) of the 44 estuaries with higheutrophic conditions.

Only six (14%) of the 44 estuaries with high-leveleutrophic conditions have corresponding high-level nitrogen inputs. An additional 22 of the 44estuaries have moderate-level nitrogen inputs.

Of the 44 estuaries with high-level eutrophic con-ditions, more than half (25) exhibit a high suscep-tibility to retaining nutrients.

Human influence on the expression of eutrophic conditions is substantial.

Symptoms of eutrophication are prevalent in the nation’s estuaries.

Assessment Data: National Estuarine Eutrophication Survey

Description: rigorous multi-year effort to synthesize the bestavailable information about eutrophic conditions

Characteristics:consistent and comparable national data set was producedthrough survey of over 300 estuarine scientists and managers

includes spatial and temporal information about eutrophi-cation symptoms, including chlorophyll a, macroalgae, epi-phytes, dissolved oxygen, submerged aquatic vegetation,and nuisance/toxic algae

survey data aggregated by estuary and final results re-viewed by experts at the Assessment Workshop

collection, evaluation, and review of the survey data was mostrigorous of all evaluations in the National Assessment

•

•

•

•

Watershed monitoring data from the U.S. Geological Sur-vey provided first-order estimates of nitrogen inputs.

U.S. Census Bureau population estimates and Depart-ment of Agriculture Agricultural Census data were usedas potential nutrient pressure indicators.

Estuarine susceptibility was determined using NOAAdata on freshwater inflow, tide, and estuarine geometry.

Characteristics: assessment based on data less rigorouslyevaluated and reviewed than for eutrophic conditions

Description: provides estimates of human-related nutri-ent inputs, estuarine susceptibility, and human influence

Assessment Data:•

•

•

1

2

Assessment Data: expert evaluations at Workshop

Description: Experts identified impaired uses they judgedto be related to estuarine eutrophic conditions.

Characteristics: Although the information is not supportedby a comprehensive national data set, it does provide arough insight into the extent of problems stemming fromeutrophic conditions.

69 estuaries were identified by workshop partici-pants as having human-use impairments relatedto eutrophication.

Compared to other impaired uses, commercial/recreational fishing and shellfisheries were iden-tified as impaired for human use in the greatestnumber of estuaries, 43 and 46, respectively.

Impaired Uses of Estuaries3

Impairments to estuarine resources, and fisheries in particular, are of great concern.

Key Findings


vii

Executive Summary

Eutrophic conditions will most likely worsen in86 estuaries by the year 2020.

Of the 86 estuaries expected to worsen, 43 exhibitonly low to moderate eutrophic conditions.

The 10 estuaries that exhibit low eutrophic con-ditions and have high susceptibility are most atrisk of future degradation if human-related nu-trient inputs increase.

The 23 estuaries with high expressions of eutrophicconditions and high susceptibility are likely to requiregreater management effort and longer response timefor results than those estuaries with low susceptibil-ity. These estuaries represent approximately 10% ofthe national estuarine surface area.

There are 10 estuaries that have low eutrophic condi-tions and high susceptibility; accordingly, they shouldbe priorities for preventive management. These estu-aries represent approximately 3% of the national es-tuarine surface area.

All of the typical point and nonpoint pollution sourceswere identified at the Workshop as important to tar-get in order to manage nutrient problems. However,there are some important regional differences in nu-trient sources, such as combined sewer overflows inthe North Atlantic.

Potential Management Concerns

Management requirements are dependent on eutrophic conditions and susceptibility.

4

Assessment Data: NOAA susceptibility and Eutrophica-tion Survey data plus expert evaluations at Workshop

Description: In addition to evaluating eutrophic condi-tions and susceptibility (see numbers 1 and 2), expertsidentified pollution sources important for managingnutrient inputs in each watershed.

Characteristics: Although the pollutant source informa-tion is not based on a comprehensive national data set,the expert evaluation of important point and nonpointsources is useful for gaining a first-order understandingat the national level of the types of actions, and the levelof effort, that will be required to address the problem.

Future Eutrophic Conditions5

Without preventive efforts, eutrophic conditions can be expected to continually worsen.

Assessment Data: projected population growth estimatesadapted from the U.S. Census Bureau and NOAA sus-ceptibility data

Description: Experts at the National Workshop usedpopulation growth and estuarine susceptibility esti-mates, along with their knowledge of the estuarine wa-tersheds, to project the direction and magnitude ofchange in current eutrophic conditions.

Characteristics: The reliability of this information is in-herently vulnerable to unforeseen changes in input lev-els from nutrient pollution sources.

Data Gaps and Research Needs6

Much remains to be done to better characterize and understand estuarine eutrophication.

Assessment Data: expert experience and knowledge, incombination with data completeness and reliabilityanalysis of the Eutrophication Survey results

Description: Experts at the National Assessment Work-shop identified data gaps and research needed to im-prove the assessment of the severity, human influence,impacts, and appropriate responses to eutrophicationproblems in estuaries.

Given all of the monitoring and research done todate, information and knowledge is still inad-equate in 48 estuaries (low confidence or inad-equate data for assessment). These estuaries rep-resent approximately 25% of the nation’s estua-rine surface area.

All participants in the National Assessment pro-cess agreed that research is needed to clarify thelinkages between eutrophication and impacts onestuarine resources, including fisheries, recreationand tourism, and risks to human health.


viii

Executive Summary

A national strategy, which incorporates the resultsof this assessment, should be developed to helpset priorities and support decision-making at thenational level.

The strategy should focus on management, moni-toring, and research, and should effectively inte-grate with regional, state, and local programs.

For estuaries in serious condition, prioritiesshould focus on management action; for those inless serious condition but at risk, the focus shouldbe on monitoring and prevention.

Estuaries for which there is insufficient informa-tion for evaluation should undergo basic moni-toring and assessment activities.

Data Gaps and Research Needs, continued6

Toward A National Strategy7

Assessment results will be valuable in setting national priorities.

Assessment Data: expert experience and knowledge base

Description: These recommendations were developedat the National Assessment Workshop from facilitateddiscussions with the participating estuarine eutrophi-cation experts.

The National Assessment process confirms thatmuch remains to be done to adequately charac-terize nutrient pressure on estuaries. Better quan-tification is needed of total nutrient inputs, inputsby source, and estimators of nutrient pressure(e.g., population, land use). Atmospheric andgroundwater inputs are least well quantified.

Better characterization of physical factors isneeded, including basic circulation patterns, ef-fects of weather patterns, climate change, chang-ing land use, and resultant effects on nutrient de-livery, circulation, and eutrophic conditions.

Other research needs include defining the relation-ship between nutrient inputs and toxic blooms, bet-ter characterization of assimilative capacity, andcharacterization of the effects of seasonal popula-tion changes.

Key Findings, continued


Estuarine Eutrophication: Nutrient Sources and Effects in EstuariesEutrophication is a process in which the addition of nutrients to water bodies stimulates algal growth. Under natural conditions, this is usually a slowprocess that results in healthy and productive ecosystems. In recent decades, however, a variety of human activities has greatly acceleratednutrient inputs to estuarine systems, causing excessive growth of algae and leading to degraded environmental conditions.

Eutrophication Diagram

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x


1

Estuarine Eutrophication: Background tothe ProblemEutrophication refers to a process in which the ad-dition of nutrients to water bodies, primarily nitro-gen and phosphorus, stimulates algal growth. Thisis a natural process, but it has been greatly acceler-ated by human activities. Estuaries have always re-ceived nutrients from natural sources in the water-shed and from the ocean. In recent decades, how-ever, population growth and related activities, suchas various agricultural practices, wastewater treat-ment plants, urban runoff, and the burning of fossilfuels, have increased nutrient inputs by many timesthe levels that occur naturally.

Increased nutrient inputs promote a complex arrayof symptoms, beginning with the excessive growthof algae, which, in turn, may lead to other, more se-rious symptoms. In addition to the rate of algalgrowth, nutrient inputs may also affect which algalspecies are favored. This process is poorly under-stood, but some unfavorable species (e.g., Pfiesteria)appear to be linked to nutrient inputs.

This report presents the results of a comprehensive National Assessment to address the problem of estuarine eutrophication.The assessment includes evaluations of eutrophic conditions, human influence, impaired estuarine uses, future conditions,data gaps and research needs, and recommendations for a national strategy to respond to the problem.

Eutrophication refers to a process inwhich the addition of nutrients towater bodies stimulates algal growth.In recent decades, human activitieshave greatly accelerated nutrient in-puts, causing the excessive growth ofalgae and leading to degraded waterquality and associated impairments ofestuarine resources for human use.

Introduction

In recent decades, eutrophication problems havebeen reported globally, from the Baltic, Adriatic, andBlack Seas, to the estuaries and coastal waters of Ja-pan, China, and Australia. Eutrophic symptomshave also been observed in the United States, includ-ing the Chesapeake Bay, Long Island Sound, and thenorthern Gulf of Mexico. More recently, it has be-come clear that nearly all U.S. estuaries exhibit somelevel of eutrophic symptoms, although the scale, in-tensity and impacts vary widely, as do the levels ofnutrient inputs that produce these symptoms.

Whether nutrient additions result in degraded wa-ter quality depends on the extent of additional in-put and on natural characteristics that affect estua-rine susceptibility to nutrients. In some estuaries, nu-trients cause dense algal blooms to occur for monthsat a time, blocking sunlight to submerged aquaticvegetation. Decaying algae from the blooms usesoxygen that was once available to fish and shellfish.In other estuaries, these or other symptoms may oc-cur, but less frequently, for shorter periods of time,or over smaller spatial areas. In still other estuaries,the assimilative capacity, or ability to absorb nutri-ents, may be greatly reduced, though no other symp-toms are apparent. These eutrophic symptoms areindicative of degraded water quality conditions thatcan adversely affect the use of estuarine resources,including commercial and recreational fishing, boat-ing, swimming, and tourism. Eutrophic symptomsmay also cause risks to human health, including se-rious illness and death, that result from the consump-tion of shellfish contaminated with algal toxins, orfrom direct exposure to waterborne or airborne tox-ins.

It should be noted that although nutrients causeeutrophic symptoms, other human and natural in-fluences may cause or affect the expression of such

A red tide causes a fish kill.Photo courtesy of Woods Hole Oceanographic Institution


2

Introduction

symptoms. These influences include engineeredwater flow, which decreases estuarine flushing rates;and development, dredging, and disease, whichchange nutrient assimilative capacity through lossesof wetlands, sea grasses, oysters, and other filterfeeders. In addition to nitrogen and phosphorus,there are other nutrients (e.g., silica) and trace ele-ments that may be important under certain condi-tions, but their role is less understood.

Climate changes may also be significant for futureconditions. Global warming may result in increasedwater temperatures, causing lower dissolved oxy-gen with no changes in nutrient inputs. At the sametime, flushing times and exchange rates might in-crease with rising sea levels, which could possiblyoffset these effects.

For more than 40 years, scientists and natural re-source managers have worked to understand, docu-ment, and resolve the complex issues associated witheutrophication in the nation’s estuaries. Nonetheless,information concerning algal blooms, low dissolvedoxygen, and other eutrophic symptoms was slow tocapture the attention of the public, administrators,and legislators. Recently, the consequences of thesesymptoms have become more apparent, helping toraise awareness of nutrient-related environmentalproblems. For instance, extensive losses of sub-merged aquatic vegetation and the associated lossof fish habitat have occurred, many coastal waterbodies have suffered worsening episodes of low dis-

solved oxygen, and blooms of nuisance and toxicalgae have been occurring in new areas. For example,Pfiesteria was first identified as a major fish-killingagent in the Neuse and Pamlico River estuaries ofNorth Carolina in 1992; in 1997, outbreaks occurredin tributaries of the Chesapeake Bay, where they hadpreviously not been observed.

Given the rising concern of the scientific commu-nity and the public at large, NOAA began to inves-tigate and evaluate the need for a more deliberatenational response to the problem of estuarineeutrophication. In order to determine the nationalextent of this problem and to provide a basis for anappropriate and effective national response, it wasnecessary to survey the overall symptoms ofeutrophication within the nation’s estuaries. Histori-cal information and ongoing field programs offeredthe raw materials, but the task remained to constructa comprehensive and consistent characterization ofthe symptoms of eutrophication. In addition, it wasessential to present the results of the survey withinthe context of everyday use impairments (e.g., swim-ming, fish consumption) that are important to theAmerican public. In fact, the population of U.S.coastal and upstream areas is projected to increaseby more than 13 percent by 2010, suggesting thatnutrient-related problems are likely to get worse.This underscores the need to stimulate additionalpublic involvement by presenting and publicizingthe best available information to concerned citizens,resource managers, and policy makers alike.

Figure 1. Data characteristics of NOAA’s Estuarine Eutrophication Survey

*See Appendix A for detailed descriptions of the symptoms.

DATA SHEETS COMPILED FOR 138 ESTUARIES REGIONAL DATA SUMMARIES COMPILED

Between 120 - 1,200 Data Values per Estuary

Chlorophyll a

Turbidity

Suspended Solids Problems

Nuisance Algae Problems

Toxic Algae Problems

Macroalgae Problems

Epiphyte Problems

Total Dissolved Nitrogen

Total Dissolved Phosphorus

Anoxia

Hypoxia

Biological Stress

Primary Productivity Dominance

Pelagic Community Dominance

Benthic Community Dominance

Submerged Aquatic Vegetation (SAV)

Eutrophication Symptoms*

Existing Conditions

Concentrations

Presence/Absence of Conditions

Spatial Coverage

Months of Occurrence

Frequency of Occurrence

Duration of event

Trends in Conditions (1970 - 1995)

Direction and Magnitude of Change

Frequency

Duration

Spatial coverage

Dominance Shifts

Contributing Factors to Change

Reliability of Information

Symptom Information Collected for Each Salinity Zone

North Atlantic

Middle Atlantic

South Atlantic

Gulf of Mexico

Pacific

Eutrophication

Survey Data

Summary


3

Introduction

The Nation’s First ComprehensiveEstuarine Eutrophication AssessmentSince its inception in 1992, NOAA’s National Estua-rine Eutrophication Survey has synthesized the bestavailable information on eutrophication-relatedsymptoms from more than 300 scientists and envi-ronmental managers. Recently published in five re-gional reports, the data characterize the spatial do-main, severity, duration, frequency and past trendsof 16 eutrophication related conditions in estuariesof the coterminous United States (NOAA 1996,1997a, 1997b, 1997c, 1998).

The 138 estuaries characterized in this study repre-sent more than 90 percent of both the total estuarinewater surface area and the total number of majorU.S. estuaries. Although not an estuary, the Missis-sippi River Plume is also included because of its im-

portance to the Gulf of Mexico and associated estu-aries to the west. Alaska, Hawaii and U.S. territo-ries were not included in this assessment due to lim-ited resources.

A common spatial framework (salinity zones repre-senting tidal fresh, mixing, and saltwater environ-ments) and predefined data categories were used toconsistently characterize the information on condi-

tions and trends for each estuary. In all, this surveyproduced an array of data containing more than40,000 data values (120 to 1,200 per estuary; Figure1). While providing the best possible information onthe problem, this array of data was also challengingto interpret.

The National Report: A Challenge toInterpret the DataNOAA worked with a “Core Group” of 15 scientistsand resource managers (see Acknowledgments) todevelop and apply methods that would best inte-grate the survey data for each estuary. It seemed rea-sonable that eutrophication symptoms and theirtime/space characteristics could be combined in away that provided a single value to represent thestatus of eutrophication symptoms in each estuary.Moreover, this index would allow comparisons,

ranking, and priority-setting amongestuaries, as well as facilitate sum-maries of national and regional re-sults. To accomplish this, two ob-stacles—data quality and a lack ofmethodology for combining numer-ous parameters into a single value—would have to be overcome.

Data Quality. An analysis of datacompleteness and the reliability ofsymptom data was performed forall estuaries so that confidence lev-els could be estimated for the data.For 17 estuaries, symptom datawere so limited that an assessmentof overall eutrophic conditionscould not be made. Most of thesewere on the Pacific Coast. For 31other systems, some of the symp-tom data provided by the expertswas rated as “speculative” becauseit was based on spatially or tempo-rally limited field observations. Theoverall confidence levels for theseestuaries was therefore assessed aslow. The evaluations for each symp-tom were carried through the as-sessment process to provide a basis

for assigning a confidence rating to the overall as-sessment of eutrophic conditions. This confidenceevaluation is important, because incomplete or un-certain data were sometimes included in the overallassessment because it was the best information avail-able.

Developing a Methodology to Aggregate Symptom Data.There was no method available for combining symp-

Experts interpret survey results at the National Assessment Workshop.


4

Introduction

tom data into a single assessment for each estuary;therefore, the Core Group had to address severalquestions while determining the best way to inte-grate the existing data:

Are all eutrophic symptoms and their character-istics equally important? Should all 16 symptomsbe considered in the national assessment? Do cer-tain symptoms logically group or occur in a linearsequence?

Do all eutrophic symptoms have the potential toexist in all estuaries?

Is the threshold for symptoms the same in all es-tuaries? For example, does a given concentrationof chlorophyll a represent “high” eutrophic symp-toms in all estuaries?

The Eutrophication Model. To help overcome theseobstacles and properly interpret the information, theCore Group participated in two work sessions to de-velop and test several analytical and numericalmethods. Ultimately, a single model was developedthat made maximum use of the survey data. Whilethis model does not account entirely for the com-plexity of this issue, it uses available information tobest describe the sequence and severity of eutrophicconditions (Figure 2). The model used six symptomsthat were most directly related to nutrient inputs.Three primary symptoms, algal abundance (usingchlorophyll a as an indicator), epiphyte abundance,and macroalgae, represent the first possible stage ofwater-quality degradation associated with eutrophi-cation. Although nitrogen and phosphorus concen-trations in the water column are related to nutrientinputs, they are also influenced by other biologicaland chemical processes. As a result, elevated con-centrations do not necessarily indicate that eutrophic

symptoms are present, nor dolow concentrations necessarilyindicate that eutrophication isnot present. As an example,chlorophyll a concentrationsmay be very high while dis-solved nutrient concentrationsare low. This scenario is com-mon during peak phytoplank-ton production because theseorganisms assimilate the nutri-ents very efficiently. Thus, nu-trient concentrations in the wa-ter column were not included asprimary symptoms in themodel.

In many estuaries, the primarysymptoms lead to secondarysymptoms, such as submergedaquatic vegetation loss, nui-sance and toxic algal blooms (al-though for toxic forms the link-age is not well established), andlow dissolved oxygen. In somecases, secondary symptoms canexist in the estuary withoutoriginating from the primarysymptoms. This occurs, for in-stance, in many North Atlanticestuaries where toxic algalblooms are transported from thecoastal ocean. In other places,disease or suspended sedimentshave contributed to declines insubmerged aquatic vegetation.

Nitrogen and Phosphorus

Extreme Chl-a Concentrations

Problematic Epiphytic Growth

SAV Spatial Coverage

Diatoms to Flagellates

Benthic Dominance to Pelagic Dominance

AnoxiaHypoxiaBiological Stress

Nuisance Bloom Problems

Toxic Bloom Problems

Primary Symptoms

Secondary Symptoms


Problematic MacroalgalGrowth


Loss of Submerged Aquatic Vegetation

SAV Spatial Coverage Trends

Decreased Light Availability

Algal Dominance Changes Harmful Algae

Increased Organic MatterDecomposition

Low Dissolved Oxygen

External Nutrient Inputs

Figure 2. The simplified eutrophication model used for the National Assessment

•

•

•


5

Introduction

Determining Overall Eutrophic Conditions. A nu-merical scoring system was developed to integrateinformation from all six primary and secondarysymptoms to determine the overall status ofeutrophic symptoms in each estuary. This scoringsystem was implemented in three phases accordingto the methods described in Figure 3 (see AppendixA for a detailed description).

First, a single index value was computed from allprimary symptoms. The scoring system gave equalweight to all three symptoms and considered thespatial and temporal characteristics of each. Thescores for the three symptoms were then averaged,resulting in the highest values being assigned to es-tuaries having multiple primary symptoms that oc-cur with great frequency, over large spatial areas of

the estuary, and for extended periods of time. Like-wise, the lowest scores indicate estuaries that exhibitfew, if any, characteristics of the primary symptoms.

Next, a single index value was computed from allsecondary symptoms. The scoring system again gaveequal weight to all symptoms and their spatial andtemporal characteristics. The highest score of any ofthe three symptoms was then chosen as the overallsecondary value for the estuary. This weights the sec-ondary symptoms higher than the primary symp-toms, because the secondary symptoms take longerto develop, thereby indicating a more chronic prob-lem, and being more indicative of actual impacts tothe estuary.

Finally, the range of numeric scores assigned to pri-mary and secondary symptoms was dividedinto categories of high, moderate, and low. Pri-mary and secondary scores were then com-pared in a matrix so that overall categoriescould be assigned to the estuaries (Figure 3).Estuaries having high scores for both primaryand secondary conditions were considered tohave an overall “high” level of eutrophication.Likewise, estuaries with low primary and sec-ondary values were assigned an overall “low”level of eutrophication. The Core Group mem-bers, using the matrix as a guide, then assignedscores to the remaining estuaries based on theirinterpretations of each estuary’s combinedvalues.

Interpreting the Model Results. While themodel offered a potentially wide scale overwhich to define the severity of the problem,few of the 138 estuaries or the Mississippi RiverPlume actually fell at either extreme of this con-tinuum, where the numerical scoring systemsare more easily interpreted. Logically, estuar-ies with few primary symptoms and low nu-meric scores were considered to be relativelyunaffected by nutrient-related conditions whencompared to estuaries with both primary andsecondary symptoms and higher numericscores.

Most estuaries showed varying degrees of bothprimary and secondary symptoms, so that themeaning of these scores was more difficult todetermine. This was particularly true for twoconditions, for which these general guidelinesfor interpretation were offered:

High or moderate primary symptoms and low sec-ondary symptoms. These estuaries have rela-

Primary and Secondary Symptom Index values are ranked and split into categories as follows:

Category AssignedScore Range

2

1 Individual scores are determined for the primary symptoms and combined into a single primary symptom index. Individual scores are determined for the secondary symptoms and combined into a single secondary symptom index.

3Primary and Secondary Symptom Categories are cross compared in a matrix to determine the overall level of expression of eutrophic conditions.

OVERALL LEVEL OF EXPRESSION OF EUTROPHIC CONDITIONS

LOW

MODERATE

MODERATE LOW MODERATE HIGH

Moderate secondary symptoms indicate substantial eutrophic conditions, but low primary symptoms indicate other factors may be involved in causing the conditions.

Level of expression of eutrophic conditions is minimal.

High secondary symptoms indicate serious problems, but low primary symptoms indicate other factors may also be involved in causing the conditions.

Primary symptoms beginning to indicate possible problems but still very few secondary symptoms expressed.

Primary symptoms high but problems with more serious secondary symptoms still not being expressed.

Level of expression of eutrophic condtions is substantial.

Substantial levels of eutrophic conditions occurring with secondary symptoms indicating serious problems.

Primary symptoms high and substantial secondary symptoms becoming more expressed, indicating potentially serious problems.

High primary and secondary symptom levels indicate serious eutrophication problems.

MODERATE LOW HIGH

MODERATE MODERATE HIGH HIGH

Secondary Symptoms

Pri

mar

y S

ymp

tom

s

Low Moderate High0 0.3 0.6 1

Low

Mod

erat

eH

igh

0.3

0.6

1

In This Report:LOW and MODERATE LOW are grouped together as LOW.HIGH and MODERATE HIGH are grouped together as HIGH.

Low> <0 0.3

0.3 0.6> < Moderate

10.6 <> High

Figure 3. Steps followed in determining the overall level of expression ofeutrophic conditions in estuaries


6

Introduction

tively well developed conditions associated with al-gal blooms, epiphytes, and/or macroalgae, whichsuggests that they are in the early stages of eutrophi-cation and may be on the edge of developing moreserious conditions. These systems may be suscep-tible to additional nutrient inputs and could beginto develop secondary symptoms of eutrophication.

High or moderate secondary symptoms and low primarysymptoms. For these estuaries, advanced secondarysymptoms exist, even though the “prerequisite” pri-mary symptoms (as suggested by the model) maynot be well developed. Three possible interpretationsare offered to describe these conditions. For someestuaries, the secondary conditions were transportedfrom offshore coastal areas, rather than originatingwithin the estuary. This occurs, for example, withtoxic bloom conditions in North Atlantic estuaries.Alternatively, it is possible that nutrient-related wa-ter quality conditions have recently improved, butthe response time to reduce secondary symptoms islonger than it is for primary symptoms. The second-ary symptoms that remain may be residual condi-tions that also may improve as nutrient concentra-tions continue to decrease. Finally, it is possible thatsecondary conditions in an estuary are related onlypartially, or not at all, to nutrient enrichment. Forexample, submerged aquatic vegetation losses in LongIsland Sound have been attributed to both disease andnutrient enrichment.

Through the use of a simple model, a frameworkwas established to help understand the sequence,processes, and symptoms associated with nutrientenrichment. Despite its limitations (e.g., the modeldoes not account for changes in assimilative capac-ity from losses of wetlands), the model representsthe first attempt to synthesize large volumes of dataand to derive a single value for eutrophication ineach estuary. With this foundation, the next stepsare to (1) expand understanding of the relationshipbetween eutrophication and nutrient sources, and(2) evaluate appropriate responses to the problem.

Extending the Assessment: Toward aNational StrategyThis National Assessment focuses on the data inNOAA’s Estuarine Eutrophication Survey, the fun-damental goal of which was to describe the scale,scope, and severity of nutrient enrichment condi-tions nationwide, and to compare the various ex-pressions of eutrophic symptoms in individual es-tuaries. In a sense, the model represents a form ofenvironmental triage—separating estuaries that arein serious condition, but could potentially improve,from those that presently do not experience many

symptoms, but are seemingly at risk. In turn, thisrepresents a starting point for understanding whythese conditions exist, how and why conditions dif-fer across estuaries, whether certain problematic con-ditions may respond to remedial actions, and whichof these actions would best protect estuaries fromfurther degradation.

To do so means to go beyond the survey data. At thevery least, more information is needed about themagnitude and sources of nutrient inputs, the natu-ral ability of estuaries to flush or assimilate incom-ing nutrients, and the relative influence of both ofthese factors on the expression of eutrophication.Moreover, these results need to be associated withuse impairment and public health issues that bringthe message to the public and help to set prioritiesfor management and research activities. With theguidance of the Core Group, the National Assess-ment was expanded to include additional data setsthat begin to examine these linkages.

Expanding the Model. To accommodate the addi-tional analyses, the original eutrophication modelwas expanded (Figure 4) so that eutrophic symp-toms could be compared with other national datasets, specifically estuarine transport (i.e., flushing,also referred to as susceptibility), nutrient inputs andsources, and eutrophication-related estuarine useimpairments. The data for these assessments werederived from a variety of sources, described below.These assessments were intended to allow generalobservations about the linkages between symptoms,nutrient loading and susceptibility, and betweeneutrophic conditions and use impairments. Recom-mendations for potential responses to the problemwere developed from conclusions based on theseobservations.

Susceptibility. Estimates were made of the naturaltendency of an estuary to retain or export nutrients.The rate at which water moves through the estuarywas determined by examining tidal action and thevolume of freshwater flowing in from rivers. In gen-eral, if the water (and nutrients) are flushed quickly,there is not sufficient time for problems to developand the estuary is not particularly susceptible. If theestuary acts more like a bathtub, with nutrient-richwater sitting in the system for a long time, then thereis time for nutrients to be taken up by algae. Theseestuaries are more susceptible to developingeutrophic symptoms.

Although only dilution and flushing were includedin this susceptibility estimate, biological processesmay also affect susceptibility. For instance, filter feed-ers raise an estuary’s capacity to assimilate more


7

Introduction

nutrients before showing symptoms. Wetlands,which retain nutrients that might otherwise enterestuarine waters, also improve an estuary’s abilityto fend off eutrophic symptoms.

Nutrient Inputs. The level of nutrients entering es-tuaries is a critical factor in determining the level towhich they will develop symptoms. Excess nutrientinputs are mainly human-related and are due to highcoastal population density, various agricultural prac-tices (e.g., fertilizer applications, animal feedlot op-erations), the burning of fossil fuels, and sewagetreatment effluents.

Estuarine Use Impairments. Impaired resources (interms of human use) were evaluated to gain a basicunderstanding of the level of negative impacts oc-curring in the nation’s estuaries. These include im-pacts to recreational activities, such as swimmingand boating, as well as to commercial operations,such as fishing and shellfishing.

Potential Management Concerns. Evaluations werealso made of the most important sources to target inorder to manage nutrient inputs into estuaries.

Data Sets and Data Quality. NOAA had access tonational data sets that were used for characteriza-tions; however, the assessments were largely basedon the knowledge and experience of the Core Groupand other Workshop participants.

For nutrient-loading estimates, NOAA providedcomparative data for 1987 (adapted from the U.S.Geological Survey’s SPARROW model; Smith et al.,1997) for five major sources: fertilizer, livestockwastes, point sources, atmospheric deposition, andnonagricultural sources. In addition, NOAA pro-vided information on coastal population and landusage, which were used as comparative estimatorsof loading. Estuarine susceptibility estimates werebased on an estuary’s dilution potential and flush-ing potential, which are calculated from freshwater


USGS SPARROW MODEL, NOAA CA&DS DATA, CORE GROUP EUTROPHICATION SURVEY DATA CORE GROUP

Potential Effects and Use Impairments


Loss of Submerged Aquatic

Vegetation

Algal Dominance Changes

Nuisance/Toxic Algal Blooms

Increased Organic Matter

Production


Secondary Symptoms

Primary Symptoms

External Nutrient Inputs and Susceptibility

Loss of Habitat

Commercial Fishing Recreational FishingTourism

Offensive Odors

Aesthetic ValuesTourism

Fish Kills

Commercial Fishing Recreational FishingAesthetic ValuesTourism

Commercial Fishing Recreational FishingHuman Health ProblemsSwimmingTourism

Increase of Algal Toxins

Loss of Habitat

Commercial Fishing Recreational FishingTourism

Influence of Physical and

Biological Processes

(i.e. freshwater inflow, flushing,

wetlands uptake, filter feeders)

Figure 4. The expanded eutrophication model


8

Introduction

inflow, tidal prism, and estuary geometry (NOAA’sCoastal Assessment & Data Synthesis System, 1998).These data sets were synthesized and interpreted lessrigorously than the symptom data, and thus, weremore speculative than the data for eutrophic symp-toms.

The assessment of estuarine-use impairments andmanagement targets was not based on hard data;rather, it was derived from the expert knowledge ofparticipants at the National Assessment Workshop.Despite the speculative nature of these assessments,the information was still very useful, providing in-sight into the consequences of eutrophic symptomsin estuaries, and into the most effective managementactions for reducing them.

See Appendix A for details on the methods and in-formation sources used in the assessment.

Organizing the Results: Seven KeyQuestionsSeven questions, which follow the logic sequence ofthe expanded eutrophication model, were developedto help organize results for the National Assessment.Question 1 examines the results of the model. Ques-tions 2 through 4 examine linkages between thesesymptoms, pollution sources, and coastal use im-pairments. Questions 5 through 7 identify prioritymanagement, monitoring, and research needs.

1. What are the severity and extent of eutrophic con-ditions exhibited within the estuaries of the UnitedStates?This analysis is based on the eutrophication data setand its interpretation using the eutrophicationmodel.

2. To what extent are eutrophic conditions in U.S.estuaries caused by human activities?The U.S. Geological Survey SPARROW model pro-vided first-order estimates of nutrient loads for 1987from five major sources. Population estimates andAgricultural Census data also were used to repre-sent the potential for nutrient sources. In addition,an indicator of estuarine flushing potential was de-veloped based on freshwater inflow, tide, and es-tuarine geometry.

3. To what extent do eutrophic conditions impairthe use of estuarine resources, and what are the im-portant impaired uses?Core Group members selected from a list of sevenuse impairments for each estuary. This list includedrecreational and commercial fishing, fish consump-tion, shellfishing, swimming, boating, aesthetics, andtourism.

4. Where should management efforts be targeted toachieve the greatest benefit toward remediation andprotection from future degradation, and what arethe most important sources to target?Core Group members selected from a list of 10 pointand nonpoint nutrient source targets.

5. To what extent can the severity and extent ofeutrophic conditions be expected to increase by theyear 2020, given the natural susceptibility of estu-aries and the potential for increasing nutrient in-puts?Projected population growth estimates were usedto represent the potential for future nutrient inputsand thus, changes in eutrophic conditions. Suscep-tibility was used to determine the expected severityof change.

6. Which data gaps and research and monitoringneeds are most critical in terms of improving theability to assess and respond to eutrophic condi-tions?Core Group members listed these, based on their ex-perience and the findings of Questions 1 through 5above.

7. How can the results of this assessment be trans-lated into a national strategy?Recommendations were developed from discussionsbetween members of the Core Group.

Using this Report and the DataThis report contains five sections that are organizedaccording to the seven questions listed above. Thereport emphasizes the results from the eutrophicsymptoms model (i.e., Question 1) as they representthe culmination of the multi-year survey work andprovide an unprecedented classification for thenation’s estuaries. The results of the expanded as-sessment model (i.e., Questions 2 through 7) are alsoprovided, but at a more general level consistent withthe less rigorous methods of data collection. Themost direct responses to the seven questions are pro-vided in the Executive Summary, while the NationalOverview and Regional Summaries sections aresupplemented by mapped and tabular displays ofthe synthesized results. The Conclusions and Rec-ommendations sections propose next steps, as sug-gested by the Core Group and other Workshop par-ticipants. The data and methods used in this Na-tional Assessment are described in the Appendices.The digital data can be accessed on-line at:http://cads.nos.noaa.gov


9

National Overview

The expression of overall eutrophic con-ditions is high in 44 U.S. estuaries. Theseestuaries are located mainly in the Gulfof Mexico and Middle Atlantic regions;however, certain estuaries along allcoastlines exhibit high levels ofeutrophic conditions.

This assessment characterizes the overall eutrophic conditions and the water-quality problems associated with nutrientenrichment for 138 U.S. estuaries. A Core Group of eutrophication experts collaborated with NOAA and was instrumentalin developing methods to assess the results of the National Eutrophication Survey. At a National Assessment Workshop,the Core Group and additional experts reviewed and interpreted the Survey results, and analyzed the factors that influencethe development of problematic conditions. They also reported on impairments in estuarine uses, potential managementconcerns, and the future outlook to the year 2020. Note that the Mississippi River Plume was also characterized, and iscounted as an additional “estuary” in the figures, but is not included in surface area statistics.

Eutrophic ConditionsThe assessment of overall eutrophic conditions isbased on the combined level of expression of sixsymptoms: chlorophyll a, epiphyte abundance,macroalgal abundance, depleted dissolved oxygen,submerged aquatic vegetation loss, and nuisance/toxic algal blooms. The level of expression of each isdetermined by the concentration, spatial coverage,frequency of occurrence, and/or other factors (referto Figure 3, page 5).

For each symptom assessment, an evaluation of thelevel of confidence was made based on the tempo-ral and spatial representativeness of the data. Theconfidence evaluation is important, because in somecases the data were incomplete or uncertain, but stillprovided the best information available and the onlymeans of presenting a national picture. These symp-tom confidence ratings provided the basis for evalu-ating the confidence of overall eutrophic conditions.

The data for 17 estuaries were too sparse to providean overall view of eutrophic conditions althoughlimited data existed for certain symptoms in someof these estuaries (see page 18 for list). For an addi-tional 38 estuaries, the overall assessment confidencewas rated as low (see Appendix B).

Figure 5. Level of expression of eutrophic conditions Figure 6 . Eutrophic conditions by region

Overall Conditions. National Assessment Work-shop participants concluded that the expression ofoverall eutrophic conditions was high in 44 estuar-ies, representing 40% of the total estuarine surfacearea studied (Figure 5). These estuaries were locatedmainly in the Gulf of Mexico and Middle Atlanticregions; however, some estuaries along all coastlinesexhibited high levels of eutrophic conditions (Fig-ures 6 and 7). This means that in these estuaries, oneor more symptoms occurred at problem levels ev-ery year, or persistently, across a major part of eachestuary. An additional 40 estuaries exhibited mod-erate eutrophic conditions. When considered to-gether, the estuaries with moderate to high condi-tions represent 65% of the estuarine surface areastudied. The remaining 38 estuaries exhibited low

Moderate Moderate Low

5

10

15

20

25

30

35

High Moderate High Low

5

10

15

20

25

30

35

North Atlantic

Middle Atlantic

South Atlantic

Gulf of Mexico

Pacific

Num

ber

of E

stua

ries

Num

ber

of E

stua

ries

Eutrophic Condition

HighModerate High

Moderate

Moderate LowLow

Grouped as High in this Report Grouped as Low in this Report

0 High

0 Low

Low Confidence

Moderate to High Confidence

Moderate High to High Expression Moderate Expression Moderate Low to

Low Expression

Low Confidence


Low Confidence


Eutrophic Condition and Assessment Confidence

Grouped as High in this Report

Grouped as Low in this Report

National Overview


10

National Overview

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tion

s. T

he P

acifi

c an

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uth

Atl

anti

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gion

sco

ntai

n th

e hig

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per

cent

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f est

uari

es th

at la

ck su

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ent i

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mat

ion

to c

onfid

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y as

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ophi

c co

ndit

ions

. A

n ad

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onal

fort

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tuar

ies (

not

show

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ave

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erat

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of e

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phic

con

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ons.

Note: Conditions are not necessarily related in whole to human-related eutrophication; to various degrees natural causes and other human disturbancesmay also play a role. For instance, some estuaries in Maine are typified by natural occurrences of toxic algae, which drift in from the open ocean. Once in theestuary, however, these blooms may be sustained by human nutrient inputs.

Figure 7. Estuaries with high levels of expression of eutrophic conditions

Est

uarie

s in

thi

s ca

tego

ry e

xhib

it va

ryin

g co

mbi

natio

ns o

f eu

trop

hic

sym

p-to

ms,

incl

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gh e

xpre

ssio

ns o

f ch

loro

phyl

l a,

mac

roal

gal a

bund

ance

prob

lem

s, e

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yte

abun

danc

e pr

oble

ms,

low

dis

solv

ed o

xyge

n, n

uisa

nce

and

toxi

c al

gal

bloo

ms,

and

los

s of

sub

mer

ged

aqua

tic v

eget

atio

n. T

ypi-

cally

, thi

s m

eans

that

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e of

thes

e sy

mpt

oms

occu

r ov

er la

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ng d

urat

ions

.


11

National Overview

Chlorophyll a is a measure used to indicate the amount ofmicroscopic algae, called phytoplankton, growing in a wa-ter body. High concentrations are indicative of problemsrelated to the overproduction of algae.

Epiphytes are algae that grow on the surfaces of plants orother objects. They can cause losses of submerged aquaticvegetation by encrusting leaf surfaces and thereby reduc-ing the light available to the plant leaves.

Macroalgae are large algae, commonly referred to as “sea-weed.” Blooms can cause losses of submerged aquatic veg-etation by blocking sunlight. Additionally, blooms may alsosmother immobile shellfish, corals, or other habitat. Theunsightly nature of some blooms may impact tourism dueto the declining value of swimming, fishing, and boatingopportunities.

Low dissolved oxygen occurs as a result of large algalblooms that sink to the bottom and use oxygen during theprocess of decay. Low dissolved oxygen can cause fish kills,habitat loss, and degraded aesthetic values, resulting in theloss of tourism and recreational water use.

Losses of submerged aquatic vegetation (SAV) occur whenlight is decreased due to turbid water associated with over-growth of algae or as a result of epiphyte growth on leaves.The loss of SAV can have negative effects on the ecologicalfunctioning of an estuary and may impact some fisheriesbecause the SAV beds serve as important habitat.

Nuisance and toxic algal blooms are thought to be causedby a change in the natural mixture of nutrients that occurswhen nutrient inputs increase over a long period of time.These blooms may release toxins that kill fish and shellfish.Human-health problems may also occur due to the consump-tion of seafood that has accumulated algal toxins or from theinhalation of airborne toxins. Many toxic algal blooms occurnaturally; however, the role of nutrient enrichment is unclear.

Common Symptoms of Eutrophication

Figure 8. Level of expression of symptoms within each overall category of eutrophic condition

levels of eutrophic conditions, meaning that symp-toms were not observed at problem levels or thatproblem conditions occurred infrequently or onlyunder specific and unusual circumstances. Abouthalf of these estuaries were located in the South At-lantic and Pacific regions.

In more than 80 percent of estuaries with high andmoderate levels of eutrophic conditions, the assess-ment confidence was high; conversely, confidencewas high in fewer than half of the systems assessedas having low eutrophic conditions. Most of the es-tuaries with low confidence are located in the Pa-cific and South Atlantic regions.

Symptoms: Common Signs of Eutrophication. Theimmediate response to nutrient inputs is the over-growth of algae. The primary symptoms of increasednutrient concentrations in the water column are highlevels of chlorophyll a, epiphytes, and/ormacroalgae (see sidebar, right). It is thought that onceprimary symptoms are observed at high levels, anestuary is in the first stages of displaying undesir-able eutrophic conditions.

High expressions of chlorophyll a occurred in 39 es-tuaries, high expressions of macroalgal abundanceoccurred in 24 estuaries, and high expressions of epi-phyte abundance occurred in 11 estuaries (see Fig-ure 8 for an accounting of symptom expression bro-ken down by eutrophic condition category). Over-all, at least one of these primary symptoms was ex-pressed at high levels in 58 estuaries. In some cases,high levels may be natural, but this observation in-dicates that 40 percent of the nation’s estuaries maybe in the first stages of developing problems associ-ated with eutrophication. On a regional basis, epi-

10 20 30 40

Chlorophyll a

Epiphyte Abundance

Macroalgal Abundance


Submerged Aquatic

Vegetation Loss

Nuisance/Toxic Algae

10 20 30 40 10 20 30 40

Prim

ary

Sym

ptom

sS

econ

dary

Sym

ptom

s

High Moderate Low

High Eutrophic Conditions(44 Estuaries)

Moderate Eutrophic Conditions(40 Estuaries)

Low Eutrophic Conditions(38 Estuaries)

50Number of Estuaries Number of Estuaries Number of Estuaries

Symptom Expression


12

National Overview

phyte problems occurred mainly in Gulf of Mexicoestuaries, while higher levels of chlorophyll a andmacroalgae were observed in estuaries of all regions(Figure 9).

While high levels of primary symptoms are strongindicators of the onset of eutrophication, the second-

Figure 9. Expression of eutrophic symptomsThese maps depict estuaries with moderate to high levels of expression of eutrophic symptoms, indicating areas of possibleconcern. Note that these symptoms are not necessarily related in whole to human-related nutrient inputs; natural causes andother human disturbances may also play a role, to various degrees, in the expression of symptoms.

ary symptoms, which include low dissolved oxygen,the loss of submerged aquatic vegetation, and theoccurrence of nuisance and toxic blooms, indicatemore serious problems, even at moderate levels.Note that while there is a direct causative link be-tween nutrients and primary symptoms, there aremany other factors, both natural and human related,

A

A A

A A

A

Primary Symptoms Secondary Symptoms

Chlorophyll a Low Dissolved Oxygen

MacroalgalAbundanceProblems

EpiphyteAbundanceProblems

Nuisance and/orToxic Algal Bloom

Problems

Submerged AquaticVegetation Loss


13

National Overview

More than half of U.S. estuaries havemoderate to high expressions of at leastone of the secondary symptoms. Thisfinding is important because these symp-toms can have serious consequences, in-cluding negative impacts on commercialfish yields, degraded recreational oppor-tunities, increased risks to human health,and adverse affects on tourism.

that may contribute to the occurrence of secondarysymptoms.

Depleted dissolved oxygen was expressed at mod-erate or high levels in 42 estuaries. Twenty-seven es-tuaries had moderate or high levels of submergedaquatic vegetation loss, and 51 estuaries exhibitedmoderate or high nuisance/toxic algal blooms (Fig-ures 8 and 9). Overall, moderate or high levels of atleast one secondary symptom was observed in 82estuaries, representing 67% of the nation’s estuarinesurface area—an indication that eutrophication iswell developed and is potentially causing seriousproblems in more than half of U.S. estuaries. Thesecondary symptoms were restricted regionally, withthe exception of nuisance and toxic blooms, whichwere observed in systems along all coasts. Losses ofsubmerged aquatic vegetation were mostly limitedto the Gulf of Mexico and Middle Atlantic regions,

This crab could not survive in the anoxic zone near the mouthof the Mississippi River. Photo courtesy of Nancy Rabalais,courtesy of the National Undersea Research Program.

and low dissolved oxygen was observed mainly inthe Gulf of Mexico, Middle Atlantic, and South At-lantic regions. These geographical differences maybe useful for developing regionally specific indica-tors that are more sensitive than the nationally ap-plied model used here.

Completing the PictureThese results provide a picture of the overalleutrophic conditions in the nation’s estuaries andthe specific symptoms that occur. Nevertheless,questions remain, such as: What factors influencethe development of these symptoms? What types ofuse impairments do these symptoms cause? Whatare the management implications? At the NationalAssessment Workshop, the Core Group used dataand information about estuarine susceptibility andhuman-related nutrient inputs, which, together, pro-vided the basis for evaluating the overall human in-fluence on these conditions. Participants reliedheavily on their experience and prior knowledge toevaluate estuarine-use impairments and potentialmanagement targets. The data for these ancillary as-sessments were not as robust, and were less rigor-ously reviewed, than the Eutrophication Surveydata, and some findings were inconclusive. This in-formation was included, however, because it helpedto complete the national picture.

Influencing Factors. In an effort to determine thelevel of human influence on the development ofeutrophication, workshop participants consideredthe overall eutrophic condition with respect to nu-trient inputs and estuarine susceptibility to retainnutrients. Figure 10 (next page) shows the input dataseparately from the susceptibility data, as well asthe aggregated results, which represent the overalllevel of human influence. Although both phospho-rus and nitrogen cause nutrient enrichment prob-lems in estuaries, at the time of the AssessmentWorkshop, national-level information was availableonly for nitrogen inputs. For this reason, nitrogenvalues were used as the primary estimates of nutri-ent inputs, and information on population densityand land use was used as a general indicator of nu-trient pressure to help account for phosphorus andcorroborate nitrogen estimates. The nitrogen inputestimates were based on watershed monitoring datafrom the U.S. Geological Survey, as produced by theSPARROW model (Smith et al., 1997).

While these data were variable and did not showdistinct groupings, some generalizations could bemade. Many estuaries assessed as having high lev-els of overall eutrophic conditions also had high sus-ceptibility and moderate to high levels of nutrient


14

National Overview

inputs. These estuaries are very sensitive to nutri-ent inputs, and as a result, many were assessed ashaving a high level of human-related influence onthe development of eutrophic conditions. The con-verse also seems to hold true; that is, most estuarieswith low susceptibility and low inputs of nutrientshad a low overall level of eutrophic conditions. Theseestuaries are less sensitive to development ofeutrophic conditions even with human related nu-trient inputs.

The assessment results highlight these generaliza-tions; of the 44 estuaries with high levels of eutrophicconditions, workshop participants assessed 36 ashaving a high level of human influence on the de-velopment of conditions. It is important to note thata common feature of these estuaries was high or

moderate susceptibility. It is also noteworthy thatmost of the 44 estuaries have moderate, not high (asin only six of the estuaries), levels of nutrient inputs.In estuaries with high or moderate susceptibility,even a moderate level of nutrient input may be suf-ficient to cause serious eutrophic symptoms. In thesesystems, natural estuarine characteristics, such aslow tidal exchange, enhance the expression of symp-toms. Most of these estuaries were located in theGulf, Middle Atlantic, and Pacific regions.

In contrast, 38 estuaries exhibited low overalleutrophic conditions. The common traits of theseestuaries were lower susceptibility and lower nitro-gen inputs; 31 of these estuaries had moderate orlow nitrogen inputs, and 28 had moderate or lowsusceptibility. In these systems, natural characteris-

Figure 10. Influencing factors on the expression of eutrophic conditions

Estuarine Susceptibility

The estuarine susceptibility estimates are based on estuarineflushing and dilution capacity - freshwater inflow, tidal flush-ing, and degree of stratification. These characteristics influ-ence the transport and fate of nutrients in coastal water bod-ies, and help to determine the susceptibility of an estuary toretain nutrients. These data were derived from national datasets contained in NOAA’s Coastal Assessment and Data Syn-thesis system.

Overall Human Influence

An estimation of the overall level of human influence on theexpression of eutrophic conditions was determined for eachestuary by combining estuarine susceptibility estimates withindicators of nutrient pressure. Although nitrogen input wasused as the primary indicator of nutrient pressure, workshopparticipants made appropriate modifications to the overallnutrient pressure assessment, based on analysis of popula-tion density and land use data as general nutrient pressureindicators.

Nitrogen Inputs

Nitrogen yield estimates, adapted from USGS’s SPARROWmodel, characterize the level of nitrogen inputs to estuariesfor five major nutrient source types: point sources, fertilizer,livestock, atmospheric deposition, and nonpoint/nonagricul-tural. These data provide a rough snapshot estimation of ni-trogen input conditions for 1987.

At the National Assessment Workshop, an attempt was made to characterize the natural conditions and human activities that influence theexpression of eutrophic conditions in the nation’s estuaries. The purpose was to develop an understanding of why eutrophic conditions differamong estuaries and to provide a basis for guiding management responses to problems. These figures indicate that the response to a givenlevel of nutrient is highly variable and is primarily due to differences among estuarine susceptibility to nutrients. Some estuaries are sosusceptible that only small amounts of additional nutrients will cause problems, while others can seemingly take in large quantities and stilldisplay few eutrophic symptoms (but may pass the nutrients on to other receiving bodies downstream).

9 85

19 19

13

1013

25

Suscep

tibili

ty

Eutrophic Condition

Low Moderate High

High

Moderate

Low

Num

ber

of E

stua

ries

16

1213

15

22 22

4 36

Eutrophic Condition

Nitrogen

Input

Low Moderate High

High

Moderate

LowNum

ber

of E

stua

ries

21(14)

10(2)

6(0)

7(4)

19(10)

2 (1)8(4)

11(2)

36(5)

Low Moderate High

Eutrophic ConditionOvera

ll Human In

fluence

High

Moderate

Low

Num

ber

of E

stua

ries

(parentheses i

ndicate fra

ction

of total w

ith lo

w confid

ence)


15

National Overview

Most estuaries with high eutrophicconditions also have high levels of hu-man influence due to a combination ofmoderate to high nutrient inputs andnatural susceptibility.

tics appeared to suppress the expression of symp-toms. It should be noted, however, that 10 of the es-tuaries with low eutrophic conditions exhibited highsusceptibility.

It is important to note that although these generali-zations can be made, the relationships between nu-trient inputs and the expression of symptoms, orbetween susceptibility and the expression of symp-toms (Figure 10), are not entirely predictable. For in-stance, not all of the 44 estuaries with high eutrophicconditions had high nutrient inputs and high sus-ceptibility, though most did follow this general rule.There were exceptions, including six estuaries as-sessed with high levels of eutrophic conditions andlow human influence. Five of these are located inthe North Atlantic region, where susceptibility is lowdue to tidal ranges greater than six feet, and nitro-gen inputs are generally low due to low populationdensities and densely forested watersheds. The over-all eutrophic conditions in some of these estuarieswere assessed as high because toxic blooms occurredeach year; these events were natural, however, origi-nating offshore and then drifting into the estuaries.Once a bloom has reached an estuary, it is possiblethat land-based nutrients maintain it.

Impaired Uses Relative to Symptoms. The findingthat more than half of the nation’s estuaries havemoderate to high expressions of at least one second-ary symptom of eutrophication is of considerableimportance, because these symptoms may nega-tively impact estuarine resources in a variety of ways

(Figure 11). For instance, losses in the nation’s fish-ery resources may be directly caused by fish killsassociated with low dissolved oxygen and toxicblooms. Declines in tourism occur when low dis-solved oxygen causes noxious smells and floatingmats of algae create unfavorable aesthetic conditions.Risks to human health increase when the toxins fromalgal blooms accumulate in edible fish and shellfish,and when toxins become airborne, causing respira-tory problems due to inhalation. This report doesnot directly address economic losses, however, sea-

sonal economies may suffer wheneutrophic symptoms occur duringthe height of the tourist and/orfishing seasons. The cost of imple-menting strategies to reduce nitro-gen inputs may also be consider-able. For example, the U.S. Environ-mental Protection Agency’s LongIsland Sound Study reported in1998 that the potential cost of re-ducing nitrogen levels from pointsources alone (70 treatment plants)in the Long Island Sound water-shed would be about $2.5 billion.

The magnitude of estuarine im-pacts cannot currently be quanti-

Shellfishing is a typical impaired estuarine use. Photo courtesyof Zoe Rasmussen, Puget Sound Water Quality Action Team.

Figure 11. Number of estuaries with resources impaired for human use

Pacific 12 0 11 4 0 5 0

Gulf of Mexico 11 5 12 4 1 4 10

South Atlantic 8 3 3 1 1 0 2

Middle Atlantic 12 0 9 6 2 8 2

North Atlantic 0 0 11 0 1 0 0

National 43 8 46 15 5 17 14

Region

Com

mer

cial

/Rec

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iona

l F

ishi

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h Consumption

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ting

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Num

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uarie

s W

ith

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ired

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s

12

16

9

19

13

69


16

National Overview

Experts at the National AssessmentWorkshop predicted that more thanhalf of the nation’s estuaries are likelyto develop worsening eutrophic condi-tions during the next 20 years.

fied; however, eutrophication experts at the NationalAssessment Workshop identified estuarine uses thatthey knew or suspected to be impaired because ofeutrophic symptoms (Figure 11). Although this in-formation is qualitative, it is still useful in under-standing the nature of impaired uses on a nationalbasis. In all, some type of use impairment was iden-tified in 69 estuaries. The most frequently reportedimpairments were to commercial fishing and shell-fish harvesting. Considered regionally, fishing and/or shellfishing impairments were reported for allcoasts. Other frequently reported impairments wereaesthetics in the Middle Atlantic, and tourism in theGulf of Mexico region. The loss of assimilativecapacity—the ability of an estuary to receive nutri-ents without exhibiting symptoms—also appears tobe important, particularly in the South Atlantic.

Recommended Management Actions. The generalworkshop recommendation is for authorities to man-age from a watershed perspective, focusing on con-trollable sources of nutrients and on strategies tai-lored to individual watershed characteristics in or-der to maximize potential improvements. This is es-pecially important, given that nutrient-control strat-egies may not be universally applicable across geo-graphic regions. The individually tailored manage-ment plans should also take into account overalleutrophic conditions and the factors influencing thelevel of expression in each estuary, so that effortscan focus on estuaries that will benefit the most fromnutrient controls. For instance, the 23 estuaries withhigh expression of eutrophic conditions and highsusceptibility (which represent about 10% of the na-tional estuarine surface area studied) will likely re-quire greater management efforts and a longer re-sponse time for results, than those estuaries with low

susceptibility. In contrast, the 10 estuaries with loweutrophic conditions and high susceptibility (about3% of national estuarine area) should be prioritiesfor preventive management.

On a national basis, the most frequently recom-mended management targets were agriculture,wastewater treatment, urban runoff, and atmo-spheric deposition (Figure 12). Although previousmanagement efforts have targeted point sources,they were still one of the top three targets recom-mended. In all regions except the North Atlantic,however, nonpoint sources are the primary focus,representing 60 percent of the recommended targets.Agriculture was the most frequently recommendedtarget for the Pacific, Gulf of Mexico, and South At-lantic regions; wastewater treatment plants were im-portant in the North Atlantic; and agriculture andatmospheric sources were most frequently recom-mended in the Middle Atlantic. Notable among thepoint sources were combined sewer overflows, spe-cifically in the North Atlantic, and wastewater treat-ment plants in all regions. Of the nonpoint sources,atmospheric deposition was among the most fre-quently recommended targets, but was noted almostexclusively for the Gulf of Mexico and Middle At-lantic regions. Another important nonpoint sourceidentified as needing management action in theSouth Atlantic and Gulf of Mexico were large ani-

mal production facilities.

Future Outlook to 2020. At the NationalAssessment Workshop, projections weremade to predict what might happen toU.S. estuaries in the future. The futureoutlook was based on predictions ofpopulation growth and expert knowl-edge of specific management and de-velopment activities that are plannedfor the watersheds. Past trends werealso considered, to varying degrees,for this determination (for the mostpart, this information was not explic-itly dealt with at the Workshop; seesidebar, page 18). The future outlookassessment (Figure 13) indicates thatoverall eutrophic conditions willworsen in 86 estuaries, stay the samein 44, and improve in only eight estu-

Figure 12. Sources that experts at the National Assessment Workshop identified asmost important targets to manage nutrient inputs

Region

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te W

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Gulf of Mexico 11 0 2 9 5 11 15 1 5 11

South Atlantic 8 0 2 3 4 12 13 5 0 0

Middle Atlantic 8 1 3 0 1 5 12 0 0 12

North Atlantic 11 7 0 0 0 2 1 0 0 1

National 49 8 12 13 10 37 55 9 5 24


17

National Overview

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on p

roje

cted

pop

ulat

ion

grow

th, c

oupl

ed w

ith s

usce

p-tib

ility

to n

utrie

nt in

puts

.


18

National Overview

The assessment of symptom trends (ca. 1970to 1995) was based on data from NOAA’s Es-tuarine Eutrophication Survey. These data areless certain, and the assessments were less rig-orously reviewed at the National AssessmentWorkshop. For 51 estuaries, data was insuffi-cient to assess trends.

A greater number of estuaries were reportedto have worsening conditions for chlorophylla, epiphytes, macroalgae, nuisance blooms,toxic blooms, and submerged aquatic vegeta-tion loss, than the number of estuaries forwhich conditions improved. For dissolved oxy-gen, conditions improved in more estuariesthan those that worsened. Overall, eutrophicconditions worsened in 48 estuaries and im-proved in 14. In 26 systems, there was no trendin overall eutrophic conditions since 1970. Mostof the estuaries that showed overall improve-ment were located in the Gulf of Mexico. Thegreatest number of estuaries in which condi-tions worsened were in the Gulf of Mexico andMiddle Atlantic regions.

Worsening trends have been attributed to ageneral increase in population density in es-tuarine watersheds. Some of these estuaries arehistorically rural, with farming and urban de-velopment intensifying concurrently. Notably,recent toxic blooms in the Middle Atlantic andSouth Atlantic regions are thought to be linkedto the increase in confined animal operationsand the release of untreated animal wastes intolocal water bodies. Successes have also beenreported, with improvements in water qualityover time. These trends are attributed to theimplementation of strategies that primarilyreduce point sources, as mandated by the CleanWater Act. In addition, some of the NationalEstuary Program estuaries, such as Tampa andSarasota Bays, are good examples of success-ful nutrient-reduction strategies that have re-versed eutrophic conditions.

Past Trends in Eutrophication

In 17 estuaries, there was insufficient datato assess overall eutrophic conditions:

Merrimack RiverAlbemarle SoundPamlico SoundSt. Helena SoundLake BorgneSanta Monica BayDrakes EsteroRogue RiverCoquille River

Coos BayUmpqua RiverSiuslaw RiverAlsea RiverSiletz BayNetarts BayTillamook BayNehalem River

aries during the next 20 years. At present, overalleutrophic conditions are moderate to low in 43 of theestuaries that are predicted to worsen; conditions areunknown in 12 additional estuaries predicted toworsen. The 10 estuaries that currently exhibit loweutrophic conditions, and are highly susceptible, areat particular risk of developing worsening conditionsif nutrient inputs increase. Most of the estuaries withnegative outlooks are located in the Pacific and Gulfof Mexico regions. These predictions tend to mirror

historic trends; over time, more estuaries have experi-enced worsening conditions.

Data Gaps and Research NeedsThe greatest need is for data that better characterizethe levels of eutrophic symptoms in estuaries. For 17estuaries, there is insufficient information to assessconditions, and for many more (31), the assessmentreliability is low due to limited or uncertain data. Theseestuaries represent 25% of the nation’s estuarine area.Physical processes and levels of nutrient inputs alsoneed to be better characterized, so that causal link-ages can be made and used to develop appropriatemanagement plans.

Process-oriented research is needed to improve un-derstanding of the mechanisms involved in the pro-gressive development of eutrophication. For example,little is known about “thresholds,” such as the level ofnutrient inputs above which toxic blooms will flour-ish. Research must be done to improve the understand-ing of historically higher levels of biological grazingas a controlling mechanism, and of the ways in whichthe decline of this mechanism affects the rate of de-velopment of eutrophic symptoms. The influence ofphosphorus and other nutrients as contributors toeutrophication, relative to nitrogen, also needs furtherclarification. Climate change, specifically global warm-ing, will affect water levels, circulation, temperatureand salinity, all of which will have an effect on thesusceptibility of estuaries, and, thus, the potential de-velopment of symptoms. Finally, the combined effectsof nutrient inputs and other pollutant stressors on thehealth of estuaries should be investigated. All of thisinformation should be used to develop predictivemodels that will enhance and ensure effective man-agement actions.


19

This section focuses on five major regions of the coterminous U.S. It highlights regional differences in overall eutrophic condi-tions; the factors influencing the development of these conditions; the associated impairments to human uses of estuarine re-sources; the future outlook; and the priorities for management, data and research. Differences between regions occur due tovariations in estuarine susceptibility in combination with the level of nutrient inputs reaching estuarine waters. In some re-gions, the climate, shoreline structure, coastal topography, and circulation and flushing patterns are similar across the entireregion, and its estuaries respond similarly, for the most part, to nutrient inputs. In other regions, these characteristics varygreatly among estuaries, and identifiable subregional differences occur in response to inputs. Therefore, in addition to regionalsummaries, detailed results are provided for each of the 138 estuaries and the Mississippi River Plume. To facilitate comparisonamong the regions, brief descriptions are provided of physical settings, general land-use characteristics and the locations ofmajor population centers. Also provided are confidence levels for the assessments.

Eutrophic Conditions and Expression of Symptoms.The overall eutrophic condition is a reflection of thecombined levels of expression of six individualsymptoms: three primary symptoms (chlorophyll a,epiphyte abundance, and macroalgal abundance)and three secondary symptoms (dissolved oxygenconditions, loss of submerged aquatic vegetation,and the occurrence of nuisance/toxic algal blooms).Each estuary received an overall rating, as well asratings for the level of impact of each individualsymptom. The overall eutrophic condition, and thelevel of impact for each individual symptom, arecharacterized as high, medium, or low. In addition,improving symptoms, as indicated by the most recenttrend direction, are noted with an upward-pointingarrow. A summary table is provided to facilitate com-parison of the individual symptom levels with theoverall level of eutrophic condition (Figures 16, 19,22, 25, 28).

Data Quality. The level of confidence in the assess-ment of eutrophic conditions was determined foreach estuary characterized in this report and wasbased on the temporal and spatial representative-ness of the data. Figure 14 illustrates the varying con-fidence levels among the five regions. There are 17

estuaries for which an assessment of overalleutrophic condition was not possible due to insuffi-cient information (see box, page 18). Whenever pos-sible, information on individual symptoms was pro-vided for these estuaries.

Factors Influencing Eutrophic Conditions. Partici-pants at the National Assessment Workshop com-bined nitrogen input estimates with susceptibilityvalues for each estuary to determine the overall in-fluence of human activities on the development ofeutrophic conditions. The overall human influenceis characterized as high, moderate or low. A sum-mary table facilitates the comparison of individualand overall influencing factors with the severity ofeutrophic conditions (Figures 17, 20, 23, 26, 29).

Impaired Uses in Estuaries. Experts at the NationalAssessment Workshop identified general impair-ments due to eutrophic conditions within estuaries.The regional assessments highlight this information.

Future Outlook on Eutrophic Conditions. When con-sidering the outlook for 20 years hence, the expertsreviewed present conditions and inputs, historic con-ditions and inputs, and projections of future inputsbased primarily on projected population growth.Each regional map shows the estuaries in which con-ditions are expected to worsen or develop, and thosein which conditions are expected to improve. In otherestuaries, conditions are expected to remain thesame, or there is insufficient information with whichto make a prediction.

Management Concerns, Data and Research Needs.Workshop participants identified management tar-gets, data gaps, and research needs for each estuary.

Figure 14. Eutrophication Assessment Confidence Levels

Regional Summaries

5

10

15

20

25

30

35

North Atlantic

Middle Atlantic

South Atlantic

Gulf of Mexico

Pacific

Nu

mb

er o

f E

stu

arie

s

Level

High

Medium

Low

Confidence


20

North AtlanticNorth Atlantic

2

3

45

67

8

9

10

11

12

13

14

15

1617

18

Eutrophic Conditions and Trends

?

?

1. St. Croix R./Cobscook Bay2. Englishman Bay3. Narraguagus Bay4. Blue Hill Bay5. Penobscot Bay6. Muscongus Bay7. Damariscotta River8. Sheepscot Bay9. Kennebec/Androscoggin R.10. Casco Bay11. Saco Bay12. Great Bay13. Hampton Harbor Estuary14. Merrimack River15. Plum Island Sound16. Massachusetts Bay17. Boston Harbor18. Cape Cod Bay

1

Figure 15. Level of expression of eutrophic conditions and future trends

More than half of the North Atlantic estuaries have moderate to high eutrophic conditions, as assessed by work-shop participants. Only a few, however, have a substantial level of human influence. The major nutrient source formost North Atlantic estuarine and coastal systems is from offshore coastal waters; consequently, many of theeutrophic symptoms expressed in the region are thought to be primarily natural conditions, especially for chloro-phyll a concentrations and toxic algae. Additionally, the high degree of tidal flushing and low freshwater inputscharacteristic of many of the systems tend to minimize impacts due to human-related nutrient inputs. Futureincreases in nutrient inputs are likely to exacerbate some of these naturally occurring conditions.

High: symptoms generally occur pe-riodically and/or over extensive area.

Moderate: symptoms generally oc-cur less periodically and/or overmedium area.

Low: few symptoms occur at morethan minimal levels.

Insufficient data for analysis

Worsen: symptoms are expected todevelop or become more pro-nounced by 2020.

Improve: symptoms are expectedto decline through 2020.


21

North Atlantic

Eutrophic ConditionsOverall Conditions. Moderate or higher levels ofeutrophic conditions occurred in more than half ofthe estuarine systems, with six being in the high cat-egory. Estuaries with these conditions were locatedalong the length of the coast, with estuaries exhibit-ing low eutrophic conditions interspersed betweenthem.

Expression of Symptoms. Close to half of the estu-aries exhibited at least one of the six symptoms athigh levels. For the primary symptoms, chlorophylla was expressed at moderate levels for a majority ofestuaries; macroalgal abundance problems occurredin almost half of the systems; and epiphyte prob-lems were minimal. For the secondary symptoms,moderate to high levels of nuisance/toxic bloomsoccurred in more than half of the systems; depleteddissolved oxygen occurred at low levels in more thanhalf, and losses of submerged aquatic vegetationwere minimal.

In general, for those systems with high eutrophicconditions, nuisance/toxic algal blooms and over-abundance of macroalgae were the principle symp-toms contributing to the observed overall condition.Moderate expression of chlorophyll a and low ex-pression of depleted dissolved oxygen were also ob-served in most of the systems with high eutrophicconditions, although these symptoms tended to oc-cur regardless of overall eutrophic condition.

The North Atlantic region includes 18 estuarine systems,encompassing roughly 2,000 square miles of water sur-face area. In the northern part of the region, the coastalshoreline consists mainly of drowned river valleys char-acterized by numerous small embayments, rocky shore-line, wave-cut cliffs, and large, rocky islands. The south-ern part of the region contains more cobble, gravel, andsand beaches, and tidal marshes are more extensive. Ahigh degree of tidal flushing and low freshwater input arecharacteristic of many of these systems. Major popula-tion centers, including Portland and Boston, are locatedin this southern portion.

Submerged aquatic vegetation improved in a few es-tuaries, largely due to replanting efforts as well as re-covery from wasting disease. In Casco Bay, improve-ments in levels of dissolved oxygen appeared to berelated to point-source controls and declining Atlan-tic Menhaden runs.

The confidence levels for the assessment of eutrophicconditions were low for four estuaries. Informationwas sparsest on trends in submerged aquatic veg-etation. There are less data for the Merrimack Riverestuary than for any other system in the region.

Influencing FactorsNutrient inputs from human sources are thought tobe high in only three North Atlantic estuarine sys-tems, primarily because freshwater inflow in the re-gion is generally low and drains from watershedswith sparse populations. Susceptibility to nutrientinputs is low in most systems because of the domi-nance of tidal flushing. As a result of the low nutri-ent inputs and low susceptibility, human influenceis generally very low in the region.

Of the six estuaries exhibiting high eutrophic con-

Figure 16. Eutrophic conditions and symptoms

The major nutrient source for manyNorth Atlantic estuarine and coastalsystems is from offshore coastal wa-ters. Consequently, many of theeutrophic symptoms expressed in theregion, such as toxic algal blooms, arethought to be primarily natural con-ditions.

Eut

roph

icC

ondi

tion

Kennebec/Androscoggin Rivers

Chl

orop

hyll

a

Epi

phyt

es

Mac

roal

gae

SA

V L

oss

Low

Dis

solv

edO

xyge

n

Nui

sanc

e/T

oxic

Blo

oms

Estuary

St. Croix River/Cobscook Bay

Englishman Bay

Narraguagus Bay

Blue Hill Bay

Penobscot Bay

Muscongus Bay

Damariscotta River

Sheepscot Bay

Casco Bay

Saco Bay

Great Bay

Hampton Harbor Estuary

Merrimack River

Plum Island Sound

Massachusetts Bay

Boston Harbor

Cape Cod Bay

?

?

?

?

?

?

??

? ? ? ? ?

Symptom Expression

Primary Secondary

No Expression

High Moderate Low Insufficient Data

?

ImprovingSymptom


22

North Atlantic

Potential Management ConcernsThe most frequently noted nutrient sources to tar-get for management efforts were wastewater treat-ment plants and combined sewer overflows. Urbanrunoff, agriculture, aquaculture, and atmospheric in-puts were also identified as sources of concern, butin relatively few estuaries.

Future Outlook to 2020By the year 2020, eutrophication symptoms are ex-pected to worsen in about one-third of the systems,primarily due to increased nutrient inputs frompopulation increases and the growth of the aqua-culture industry. Of these estuaries, St. Croix River/Cobscook Bay, Great Bay, and Plum Island Soundare expected to worsen the most. Conversely, CascoBay and Boston Harbor are expected to improve, toa limited extent.

The confidence levels for the assessment of the fu-ture outlook was low for two estuaries.

Data Gaps and Research NeedsSeveral estuaries were identified as requiring betterbaseline symptom data, although only four systemswere noted to have low confidence levels for assess-ment.

Important data and research needs generally includeimproved assessments of nutrient inputs from riv-ers, groundwater, and aquaculture; better under-standing of circulation dynamics; and improved es-timates of population growth and land use. For sys-tems with seasonal population changes, research isneeded to assess the effects of winter-summer popu-lation changes on eutrophic conditions.

ditions, only one, Boston Harbor, had high humaninfluences. Furthermore, according to expert consen-sus at the National and Regional Assessment Work-shops, offshore coastal waters are the major nutri-ent source for most estuarine systems in this region.Consequently, certain eutrophic symptoms, such astoxic algal blooms, are thought to be primarily natu-ral conditions. Human-related nutrient inputs, how-ever, may exacerbate these natural conditions.

The confidence level of the assessment of anthropo-genic influence was low for three estuaries.

Impaired UsesVery few uses of estuarine resources were identifiedas being impaired by eutrophication in this region.The impaired use of shellfish resources was the mostextensive problem identified; however, shellfish-areaclosures were attributed mainly to natural toxic al-gal blooms, which can lead to paralytic shellfish poi-soning in people. Minor problems were also notedfor boating.

Figure 17. Eutrophic conditions and influencing factors

Eut

roph

icC

ondi

tion

Moderate Low

Sus

cept

ibili

ty

Nitr

ogen

Inpu

t

Ove

rall

Hum

an

Influ

ence

Englishman Bay

Narraguagus Bay

Blue Hill Bay

Penobscot Bay

Muscongus Bay

Damariscotta River

Sheepscot Bay

Kennebec/Androscoggin Rivers

Casco Bay

Saco Bay

Great Bay

Hampton Harbor Estuary

Plum Island Sound

Massachusetts Bay

Boston Harbor

Cape Cod Bay

Merrimack River

Insufficient Data

Estuary

St. Croix River/Cobscook Bay

High

?

?

Influencing Factors


23

North Atlantic

A high degree of tidal flushing and low freshwater input, characteristic of many North Atlantic estuaries, tend to minimize impactsdue to human-related nutrient inputs. Photo courtesy of Miranda Harris, NOAA.


24

Middle Atlantic

1

2

34

5

67

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

1. Buzzards Bay2. Narragansett Bay3. Gardiners Bay4. Long Island Sound5. Connecticut River6. Great South Bay7. Hudson River/Raritan Bay8. Barnegat Bay9. New Jersey Inland Bays10. Delaware Bay11. Delaware Inland Bays12. Maryland Inland Bays13. Chincoteague Bay14. Chesapeake Bay15. Patuxent River16. Potomac River17. Rappahannock River18. York River19. James River20. Chester River21. Choptank River22. Tangier/Pocomoke Sounds


?







Middle Atlantic


In this region, the expression of high eutrophic conditions is extensive and the level of human influence is high.Eutrophic symptoms are widespread and likely have substantial impacts on many estuarine natural resources. Theexpression of pronounced eutrophic symptoms tends to be more pervasive in enclosed or river-dominated estuar-ies, while ocean-influenced systems exhibit fewer impacts. There are numerous ongoing efforts to control nutrientinputs; however, the ecological response to nutrient reductions is often slow in many of these systems, and conse-quently, the positive effects of these efforts may have yet to materialize. The widespread influence of atmosphericnutrient sources, together with rapid rates of development, pose a great challenge to the control of nutrient inputsand eutrophication.


25

Middle Atlantic

Eutrophic ConditionsOverall Conditions. Estuaries with moderate to higheutrophic conditions were widespread and evenlyspaced throughout the region, with close to half ofthe estuarine systems exhibiting high levels ofeutrophic conditions, and an additional five show-ing moderate conditions.

high expressions of primary symptoms. The fiveestuaries exhibiting moderate eutrophic conditionsdisplayed similar symptoms, except that the second-ary symptoms were somewhat less severe.

An improvement in at least one symptom is notedas the most recent trend in close to half of the estu-aries. Unfortunately, most of these improvements aremodest, and follow long periods of declining condi-tions. Improving trends are a positive sign that man-agement efforts are working; however, where con-ditions are moderate to high, there is still much roomfor improvement, and efforts at nutrient controlshould be maintained and fortified. In the Chesa-peake Bay and its tributaries, for example, sub-merged aquatic vegetation suffered severe declinesin the 1960s and 1970s, primarily as the result of nu-trient enrichment, and only recently have nutrientmanagement and other factors contributed to theslight improvement.

The Middle Atlantic region includes 22 estuarine sys-tems, encompassing more than 7,790 square miles of wa-ter surface area. Coastal areas are characterized by irregu-lar shorelines, wide, sandy beaches, numerous barrier is-land formations, and extensive salt marshes. Tides rangefrom one to six feet but generally fall within the lowerpart of the range. Tidal flushing is most dominant in thenorthern part of the region, while freshwater inflow ismore important in the Chesapeake Bay systems. Land useis characterized by large urban tracts and extensive agri-cultural areas. Major population centers include Provi-dence, Hartford, New York City, Philadelphia, Baltimore,Washington, D.C., and Richmond.

Figure 19. Eutrophic conditions and symptoms

The expression of severe eutrophicconditions tends to be more pervasivein enclosed or river-dominated estu-aries, while the more ocean-influencedsystems experience fewer impacts.

Expression of Symptoms. Well over half of the es-tuaries exhibited at least one of the six symptoms athigh levels. Of the primary symptoms, chlorophylla had the most pronounced expression, with highlevels in half of the estuaries and moderate levels inthe rest. Macroalgal abundance problems occurredin 10 estuaries, and in five of these at moderate tohigh levels. Epiphyte abundance problems occurredin more than one-quarter of the estuaries. Extensiveexpressions of secondary symptoms were also notedin the region. Depleted dissolved oxygen occurredin every estuary, although it tended to be expressedat low levels. Both submerged aquatic vegetationloss and nuisance/toxic algal blooms were problemsin more than half of the estuaries, primarily occur-ring at moderate to high levels.

There did not appear to be a single symptom domi-nating the overall expression of high eutrophic con-ditions. Rather, there was a wide and varied arrayof symptoms contributing to the overall conditionsobserved. The 10 estuaries exhibiting high eutrophicconditions had varying combinations of low dis-solved oxygen, submerged aquatic vegetation loss,and nuisance/toxic algal blooms. In most of theseestuaries, these secondary symptoms coincided with

Eut

roph

ic

Con

ditio

n

Symptom Expression

Chl

orop

hyll

a

Epi

phyt

es

Mac

roal

gae

SA

V L

oss

Low

Dis

solv

ed

Oxy

gen

Nui

sanc

e/T

oxic

Blo

oms

Estuary

Buzzards Bay

Narragansett Bay

Gardiners Bay

Long Island Sound

Connecticut River

Great South Bay

Hudson River/Raritan Bay

Barnegat Bay

New Jersey Inland Bays

Delaware Bay

Delaware Inland Bays

Maryland Inland Bays

Chincoteague Bay

Chesapeake Bay (mainstem)

Patuxent River

Potomac River

Rappahannock River

York River

James River

Chester River

Choptank River

Tangier/Pocomoke Sounds

?

?

?

?

?

?

? ? ?

? ?

Primary Secondary

No Expression


?

ImprovingSymptom


26

Middle Atlantic

The confidence levels for the assessment of eutrophicconditions were generally high, although three es-tuaries were rated as low. The Connecticut River hadthe least data and the lowest confidence. Informa-tion was sparsest for trends in epiphyte abundance.

Influencing FactorsThe expression of severe eutrophic conditionstended to be more pervasive in enclosed or river-dominated estuaries, such as the Chesapeake Bayand its tributaries and the Delaware Inland Bays,while ocean-influenced systems, such as BuzzardsBay and Delaware Bay, exhibited fewer impacts (al-though these systems may have had small, more lo-calized areas of high symptoms). Nitrogen inputswere moderate to high in 15 estuaries, and suscepti-bility was moderate to high in all systems. Accord-ingly, human influence was considered to be ex-tremely strong in this region. Of the 15 estuaries with

moderate to high eutrophic conditions, 12 also ex-hibited high human influence.

Additionally, several systems displayed minimaleutrophic conditions despite a substantial level ofhuman influence. It is possible that some of thesesystems are close to developing full-scale eutrophicsymptoms. Alternatively, some of the systems maynot be as susceptible as the data indicated, or theestimates of nitrogen inputs may have been too high.

The confidence levels for the assessment of overallhuman influence were generally high; three estuar-ies were rated as low.

Impaired UsesThe loss of habitat (primarily submerged aquaticvegetation) was the most cited impaired use (15 es-tuaries), followed closely by degradation of recre-ational and commercial fishing (12 estuaries). Shell-fish resources, swimming, and aesthetic values wereimpaired in a moderate number of estuaries, whiletourism and boating were affected to a small extent.Almost all impaired uses occurred in systems inwhich eutrophic symptoms were moderate or high.

Potential Management ConcernsThe most important sources to target to managenutrient inputs in the region were identified as at-mospheric inputs, agricultural runoff, and dis-charges from wastewater treatment plants. Urbanrunoff, septic systems, combined sewer overflows,and animal operations were also noted as importanttargets, but in fewer estuarine basins.

Future Outlook to 2020Eutrophication conditions are expected to worsenslightly in 10 estuaries, and to worsen more severelyin three. In eight systems (primarily those from Buz-zards Bay south through Delaware Bay), no substan-tial changes are predicted. Great improvement is notexpected in any of the region’s estuaries.

The confidences levels for the assessment of the fu-ture outlook was low for four estuaries. The reliabil-ity of all of this information is, however, inherentlyvulnerable to unforeseen changes.

Figure 20. Eutrophic conditions and influencing factors

Eut

roph

ic

Con

ditio

n

Moderate Low

Sus

cept

ibili

ty

Nitr

ogen

Inpu

t

Ove

rall

Hum

an

Influ

ence

Insufficient Data

Estuary

High ?

Chesapeake Bay

Barnegat Bay

Delaware Inland Bays

Patuxent River

Potomac River

Tangier/Pocomoke Sounds

Long Island Sound

York River

Great South Bay

Gardiners Bay

Rappahannock River

Hudson River/Raritan Bay

Chester River

Choptank River

Maryland Inland Bays

Narragansett Bay

New Jersey Inland Bays

Delaware Bay

James River

Connecticut River

Chincoteague Bay

Buzzards Bay

Influencing Factors


27

Middle Atlantic

Data Gaps and Research NeedsBetter quantification of nutrient sources, especiallyfrom the atmosphere and groundwater, is neededto determine a more accurate assessment of nutri-ent loading pressures. A major research need for thisregion is a concrete determination of, and a moredefinitive knowledge of, the relationship betweenthe human factors that influence eutrophication andthe quality and quantity of living marine resourcesin the estuaries. This will entail clarifying and quan-tifying water-quality pathways; that is, both human-related and naturally occurring nutrient inputs, andthe nature of their cascading effects throughout thetrophic levels of the various estuarine systems.

This dense bloom of cyanobacteria (blue-green algae) occurred in the Potomac River estuary downstream of Washington, D.C.Photo courtesy of W. Bennett, U.S. Geological Survey.


28

South Atlantic

1. Albemarle Sound2. Pamlico Sound3. Pamlico/Pungo Rivers4. Neuse River5. Bogue Sound6. New River7. Cape Fear River8. Winyah Bay9. N. Santee/S. Santee Rivers10. Charleston Harbor11. Stono/North Edisto Rivers12. St. Helena Sound13. Broad River14. Savannah River15. Ossabaw Sound16. St. Catherines/Sapelo Sounds17. Altamaha River18. St. Andrew/St. Simons Sounds19. St. Marys River/Cumberland Sound20. St. Johns River21. Indian River22. Biscayne Bay

1

23

4

56

7

8

9

1011

1213

1415

161718

19

20

21

22


?

?

?

?

South Atlantic








High eutrophic conditions occur mostly in the northern and southern parts of this region. These conditions areindicated mainly by high expressions of chlorophyll a, harmful algal blooms, and low dissolved oxygen levels.More than half of the estuaries exhibiting minimal eutrophic conditions are likely to develop more pronouncedsymptoms due to increased nutrient loading. In the affected estuaries, fishing, fish consumption, and shellfishresources are identified as impaired uses. Important sources identified as management concerns are wastewatertreatment plants, large animal operations, and other agricultural activities. Urban and forestry sources will be-come more important as efforts are made to minimize future degradation, especially in systems that currentlyexhibit few impacts.


29

South AtlanticFigure 22. Eutrophic conditions and symptomsThe South Atlantic region includes 22 estuaries, encom-

passing more than 4,440 square miles of water surfacearea. The region is comprised of extensive barrier and seaislands that parallel the shoreline. The coastal environ-ment consists of shallow lagoonal estuaries, extensive tidalmarshes and drowned river valleys. Estuarine circula-tion patterns are dominated mainly by wind and seasonalfreshwater inflow in North Carolina, and mainly by fresh-water inflow and tides in South Carolina and Georgia.Estuarine circulation along the Florida coast is dominatedby wind forcing and human engineering. Tidal rangethroughout the region is moderately low to high (1.5-7.0feet) and influences mixing in the water column, prima-rily near the inlets. The dominant land uses are agricul-ture and industry, and, to a lesser extent, forestry. Majorpopulation centers include Miami, Jacksonville, and Sa-vannah.

Eutrophic ConditionsOverall Conditions. The South Atlantic region con-tains only four estuarine systems characterized ashaving high levels of eutrophic conditions: the NeuseRiver, Pamlico/Pungo Rivers, New River, and theSt. John’s River. Most of the other systems were rela-tively unaffected. Nevertheless, almost half of theregion’s estuaries exhibited eutrophic conditions atlow to moderate levels. Most of these estuaries arein South Carolina and Georgia.

Expression of Symptoms. In five estuaries, at leastone of the six individual symptoms was expressedat high levels. Of the primary symptoms, chlorophylla had the most pronounced expression in five estu-aries located in North Carolina and Florida. Of thesecondary symptoms, depleted dissolved oxygenwas considered high only in the Neuse River; how-ever, low to moderate conditions occurred in almostevery other estuary in the region. Nuisance/toxicalgal blooms occurred at high levels in both the Newand Neuse Rivers and at moderate levels in thePamlico/Pungo Rivers of North Carolina. The lossof submerged aquatic vegetation was a problem inalmost half of the estuaries, but mainly at low tomoderate levels.

In general, the symptoms most often associated withhigh expressions of eutrophic conditions were highchlorophyll a and nuisance/toxic algal blooms, al-though various levels of other symptoms wereknown to occur.

Some data existed for the Albemarle and PamlicoSounds, but it was for very limited portions of thesystems. St. Helena Sound also had insufficient datafor an overall assessment. In 10 other estuaries, theconfidence levels for assessments were low. Infor-mation was sparsest for trends in submerged aquaticvegetation.

Influencing FactorsThe overall level of human influence was low in halfof the region’s estuaries, especially in South Caro-lina and Georgia, and moderate in most of the re-maining estuaries. Human influence was most pro-nounced in the Pamlico/Pungo Rivers, the NeuseRiver and the New River.

While few estuaries in the South At-lantic exhibit high eutrophic condi-tions, many estuaries have moderateto high susceptibility. Furthermore,conditions are expected to worsen in10 estuaries that currently exhibit lowto moderate eutrophic conditions.

Eut

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Con

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Symptom Expression

Chl

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SA

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Blo

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Estuary

Albemarle Sound

Pamlico Sound

Pamlico/Pungo Rivers

Neuse River

Bogue Sound

New River

Cape Fear River

Winyah Bay

N. Santee/S. Santee Rivers

Charleston Harbor

Stono/North Edisto Rivers

St. Helena Sound

Broad River

Savannah River

Ossabaw Sound

St. Catherines/Sapelo Sounds

Altamaha River

St. Andrew/St. Simons Sounds

St. Marys River/Cumberland Sd.

St. Johns River

Indian River

Biscayne Bay

?

?

? ?

?

?

? ?

?

? ? ? ?

? ? ?

?

Primary Secondary

?

No Expression


?

ImprovingSymptom


30

South AtlanticFigure 23. Eutrophic conditions and influencing factors

Many factors influence the expression of eutrophicconditions in South Atlantic estuaries. The limitednumber of systems in which eutrophic conditionswere high generally had restricted circulation, lowtidal exchange, and moderate to high nitrogen in-puts. In most of the other estuaries, which were rela-tively unaffected by eutrophication, the influence oftidal marshes (which act as a nutrient filteringmechanism), strong tides, and low nitrogen inputscombined to keep eutrophic conditions at bay.

The confidence levels for the assessment of overallhuman influence were low in 10 estuaries.

Impaired UsesAlthough impaired uses in the South Atlantic weredifficult to relate directly to eutrophic conditions,results from the National Assessment Workshop did

suggest that the most important impaired uses oc-curring in the region were commercial and recre-ational fishing, shellfishing, and fish consumption.Swimming, boating and tourism were also affected,to a lesser extent.

Potential Management ConcernsThe areas requiring specific management focus aredriven by dominant land-use practices around theestuaries with problematic conditions. For the sys-tems with the most pronounced expressions ofeutrophication, the most important nutrient sourcesto focus on are wastewater treatment plants, largeanimal operations, and agricultural activities. In es-tuaries with intermediate to low eutrophic symp-toms, management efforts to control nutrients fromurban, agricultural, and, to a lesser extent, forestrysources, will minimize further degradation.

Future Outlook to 2020Based on the experts’ knowledge of watershed ac-tivities, population trends, and nutrient-loading es-timates, 12 estuaries were predicted to develop wors-ening eutrophication conditions through 2020; atpresent, more than half of these systems are rela-tively pristine and as yet unaffected by eutrophica-tion. Coastal Georgia and South Carolina were pro-jected to have the greatest relative population growthof all coastal regions in the nation, and thus, despitemoderate to low symptoms at present, the likelihoodthat these estuaries will develop future problems isinordinately high. In fact, the first red tide bloomsever reported in South Carolina and Georgia oc-curred in June 1999. Estuaries that currently exhibitmoderate to high levels of eutrophication, and thatwere predicted to develop worsening conditions, areCharleston Harbor, the Savannah River, St. MarysRiver, St. Johns River, and the Indian River. BogueSound, the New River, and St. Helena Sound werenoted as potentially showing improvement in thefuture.

The confidence levels for the assessment of the fu-ture outlook were low for three estuaries and mod-erate for the rest. The reliability of all of this infor-mation is, however, inherently vulnerable to unfore-seen changes.

Data Gaps and Research NeedsThe South Atlantic is generally a poorly studied re-gion. The confidence level of the assessment of over-all eutrophic condition was low for 12 systems, andan additional six were specifically identified as requir-ing improvements in basic monitoring. The need fordata in this region is critical, given the projected in-creases in population and the susceptibility of many

Eut

roph

ic

Con

ditio

n

Moderate Low

Sus

cept

ibili

ty

Nitr

ogen

Inpu

t

Ove

rall

Hum

an

Influ

ence

Insufficient Data

Estuary

High ?

Neuse River

Pamlico Sound

Pamlico/Pungo Rivers

New River

St. Johns River

Cape Fear River

Charleston Harbor

Indian River

St. Marys River/Cumberland Sound

Savannah River

Winyah Bay

Stono/North Edisto Rivers

N. Santee/S. Santee Rivers

Broad River

St. Catherines/Sapelo Sounds

St. Andrew/St. Simons Sounds

Bogue Sound

Ossabaw Sound

Altamaha River

Biscayne Bay

St. Helena Sound ?

Albemarle Sound ?

?

?

?

Influencing Factors

?


31

South Atlantic

of the systems. Other identified needs were better dataon organic as well as inorganic nutrient loads and con-centrations; time-series data sets in both impacted andpristine systems; and more data on the comparativeroles of shallow intertidal habitats and water-columnprocesses. Research on the effects of nutrient loadingin blackwater systems, and comparative data on nu-trient processing in blackwater versus alluvial rivers,were also deemed imperative.

Population growth and the associated development of relatively pristine estuarine watersheds is a major concern for the South Atlantic.Photograph courtesy of Michael A. Mallin, Center for Marine Science Research, University of North Carolina at Wilmington.


32

Gulf of Mexico

1. Florida Bay2. S. Ten Thousand Islands3. N. Ten Thousand Islands4. Rookery Bay5. Charlotte Harbor6. Caloosahatchee River7. Sarasota Bay8. Tampa Bay9. Suwannee River10. Apalachee Bay11. Apalachicola Bay12. St. Andrew Bay13. Choctawhatchee Bay14. Pensacola Bay15. Perdido Bay16. Mobile Bay17. East Mississippi Sound18. West Mississippi Sound19. Lake Borgne20. Lake Pontchartrain

21. Breton/Chandeleur Sounds22. Mississippi River23. Barataria Bay24. Terrebonne/Timbalier Bays25. Atchafalaya/Vermilion Bays26. Mermentau Estuary27. Calcasieu Lake28. Sabine Lake29. Galveston Bay30. Brazos River31. Matagorda Bay32. San Antonio Bay33. Aransas Bay34. Corpus Christi Bay35. Upper Laguna Madre36. Baffin Bay37. Lower Laguna Madre38. Mississippi River Plume

1

23

4

5 6

7

8

9

1011

121314151617

1819

20

21

2223

2425

262728

29

3031

3233

343536

37

38


?

?

The expression of high eutrophic conditions is extensive, and human influence is substantial, in the Gulf of Mexicoregion. Although there is a great diversity of estuary types, common characteristics, such as low tidal flushing,warm water, and long algal growing seasons, create conditions that make many of the region’s estuaries suscep-tible to eutrophic problems. The most significant symptoms in the overall expression of eutrophic conditions arelow dissolved oxygen and loss of submerged aquatic vegetation. Impaired resource uses are evident in many, butnot all, of the affected systems. Conditions are expected to worsen in more than half of the estuaries by 2020.

Gulf of Mexico









33

Gulf of MexicoFigure 25. Eutrophic conditions and symptomsThe Gulf of Mexico region includes 37 estuaries plus the

Mississippi River Plume, encompassing more than 24,000square miles of water surface area. The region is com-prised of a gently sloping, lowland area as part of the GulfCoastal Plain. Estuarine and coastal environments arehighly diverse, consisting of unrestricted open bays, semi-enclosed lagoons, tidal marshes and delta complexes. Thefresh water that flows naturally into estuaries can fluc-tuate greatly in the Gulf, and depends on seasonal rain-fall patterns. Estuarine circulation patterns are gener-ally wind driven, and coastal waters are usually warmerthan in other regions due to the subtropical climate. Es-tuaries have fairly low tidal energy (0.5-3.5 ft. tide range),and water depths are typically shallow when compared toestuaries in other regions. Land-use activity in the wa-tersheds is typically dominated by agricultural practices.Major population centers include Houston, New Orleansand Tampa.

Eutrophic ConditionsOverall Conditions. The Gulf of Mexico was sig-nificantly affected by elevated expressions ofeutrophication. Almost half of the estuaries werecharacterized as having high levels of eutrophic con-ditions. Estuaries noted as having the highest-levelconditions were Florida Bay, Lake Pontchartrain,Calcasieu Lake, the Mississippi River Plume, Cor-pus Christi Bay and the Laguna Madre system. Four-teen estuaries were characterized as having moder-ate levels of eutrophic conditions, and only six werecharacterized as having low-level conditions.

Expression of Symptoms. In 20 estuaries, at leastone of the six individual symptoms was expressedat high levels. Of the primary symptoms, chlorophyll awas expressed at high levels in 12 estuaries that werelocated mainly on the coasts of western Florida,Louisiana and lower Texas. In eight estuaries, epi-phytes were considered moderate to high; in sevenestuaries, magroalgal abundance was consideredmoderate to high. Of the secondary symptoms, lowdissolved oxygen occurred at high levels in four es-tuaries, mainly along the Florida coast and in theMississippi River Plume. The loss of submerged

aquatic vegetation was a problem in almost half ofthe estuaries, but usually at low to moderate levels.Nuisance/toxic algal blooms also tended to be per-

Of all regions, the Gulf of Mexico hasthe greatest percentage of estuarieswith high eutrophic conditions, de-spite low to moderate nutrient inputs.In addition to the prevalence of mod-erate to high susceptibility, the gen-erally long growing season and warmwaters result in higher levels of ex-pression of eutrophic conditions.

Eut

roph

icC

ondi

tion

Symptom Expression

Chl

orop

hyll

a

Epi

phyt

es

Mac

roal

gae

SA

V L

oss

Low

Dis

solv

edO

xyge

n

Nui

sanc

e/T

oxic

Blo

oms

Estuary

Florida Bay

South Ten Thousand Islands

North Ten Thousand Islands

Rookery Bay

Charlotte Harbor

Caloosahatchee River

Sarasota Bay

Tampa Bay

Suwannee River

Apalachee Bay

Apalachicola Bay

St. Andrew Bay

Choctawhatchee Bay

Pensacola Bay

Perdido Bay

Mobile Bay

East Mississippi Sound

West Mississippi Sound

Lake Borgne

Lake Pontchartrain

Breton/Chandeleur Sounds

Mississippi River

Barataria Bay

Terrebonne/Timbalier Bays

Atchafalaya/Vermilion Bays

Mississippi River Plume

Mermentau Estuary

Calcasieu Lake

Sabine Lake

Galveston Bay

Brazos River

Matagorda Bay

San Antonio Bay

Aransas Bay

Corpus Christi Bay

Upper Laguna Madre

Baffin Bay

Lower Laguna Madre

?

?

?

? ?

? ? ? ?

? ?

?

Primary Secondary

No Expression


?

ImprovingSymptom


34

Gulf of MexicoFigure 26. Eutrophic conditions and influencing factorsvasive, occurring in 28 estuaries, eight of which

showed high levels. All eight of these estuaries werelocated in the coastal systems of Florida, westernLouisiana and the lower Texas coast.

In the systems with high eutrophic conditions, thesymptoms that generally contribute the most to theobserved overall condition were the loss of sub-merged aquatic vegetation, increased turbidity as-sociated with high concentrations of chlorophyll a,and low levels of dissolved oxygen. Moderate tohigh levels of nuisance/toxic algal blooms and epi-phyte abundance were also major factors in systemswith pronounced expressions of eutrophication.

In general, recent improving trends are due prima-rily to better management of point and nonpointnutrient sources. Where conditions are moderate tohigh, however, there is still much room for improve-ment, and efforts to control nutrient inputs shouldbe maintained and fortified.

The Gulf of Mexico is generally a well studied re-gion; the confidence levels for the assessment ofoverall eutrophic conditions were medium to highfor 31 systems. The confidence levels for the assess-ment of overall eutrophic conditions were low foronly six systems. Data availability was generallyvery good; Lake Borgne was the only estuary withinsufficient data for an assessment.

Overall Human InfluenceThe overall level of human influence was high inmore than half of all Gulf systems and correspondedwell with high levels of eutrophic conditions (Fig-ure 27). Human influence was considered mostprominent in the Mississippi River Plume, LakePontchartrain, Upper and Lower Laguna Madre, andBaffin Bay. Noted for having relatively low humaninfluence were Rookery Bay, the Suwannee River,Apalachee Bay, and Breton/Chandeleur Sounds.

Many factors influenced the expression of eutrophi-cation in Gulf estuaries. The following influencingfactors were generally associated with moderate topronounced levels of expression: low tidal energy,low flushing rates with increased nutrient inputs,and low dissolved oxygen levels generally due towarmer waters and the longer growing season.These factors contributed significantly to the highlevels of human influence in many Gulf estuarieswith pronounced eutrophic conditions, even thoughnitrogen inputs were generally moderate (Figure 27).For example, although population density is rela-tively low in the Baffin Bay and Upper LagunaMadre watersheds, human influence is magnified

Eut

roph

ic

Con

ditio

n

Moderate Low

Sus

cept

ibili

ty

Nitr

ogen

Inpu

t

Ove

rall

Hum

an

Influ

ence

Insufficient Data

Estuary

High ?

Lake Pontchartrain

Baffin Bay

Upper Laguna Madre

Lower Laguna Madre

Calcasieu Lake

Corpus Christi Bay

Caloosahatchee River

Charlotte Harbor

Sarasota Bay

Tampa Bay

Choctawhatchee Bay

Perdido Bay

Apalachicola Bay

Pensacola Bay

Sabine Lake

Galveston Bay

San Antonio Bay

Matagorda Bay

St. Andrew Bay

Mobile Bay

East Mississippi Sound

Lake Borgne

Terrebonne/Timbalier Bays

Atchafalaya/Vermilion Bays

Brazos River

Aransas Bay

Suwannee River

West Mississippi Sound

Mississippi River

Apalachee Bay

Breton/Chandeleur Sounds

Mermentau Estuary

Barataria Bay

?

Mississippi River Plume ? ?

Florida Bay ?

South Ten Thousand Islands ?

North Ten Thousand Islands ?

Rookery Bay ?

Influencing Factors


35

Gulf of Mexico

due to these estuaries’ high susceptibility.

The confidence level in the assessment of human in-fluence was low for 11 estuaries.

Impaired UsesImpaired uses were difficult to define as being di-rectly related to eutrophication. Results from theWorkshop, however, did suggest that the most im-paired uses were recreational and commercial fish-ing and shellfishing. Habitat-level impacts, such asthe loss of submerged aquatic vegetation, were alsonoted.

Potential Management ConcernsThe areas requiring specific management focus aredriven by agriculture, which is the dominant landuse in the region’s watersheds. Management targetareas are diverse because of the varied physicalmakeup and forcing mechanisms that drive condi-tions in the estuaries. Wastewater treatment plants,industrial discharges, and agricultural practices arecommon management targets. Atmospheric inputsare important in low-flow systems. Upland inputsshould be targeted for large fluvial systems such asthe Mississippi, Mobile, and Apalachicola Rivers.

Future Outlook to 2020Of the 38 Gulf estuaries studied, 23 were predictedto develop worsening conditions over the next 20years, six of them to a high degree (Mississippi RiverPlume, Lake Pontchartrain, Corpus Christi Bay,Upper and Lower Laguna Madre, and Baffin Bay).Florida Bay, Breton/Chandeleur Sounds, andMermentau Estuary were noted as potentially show-ing signs of future improvement. The level of confi-dence for the assessment of the future outlook waslow for 12 estuaries.

Data Gaps and Research NeedsResearch areas, such as biogeochemical cycling andnutrient budget analyses, require an understandingof the processes by which elements are recycledwithin estuaries. According to the experts, these pro-cesses are poorly understood and in need of moreattention. Participants at the workshop noted thatphosphorus may be an important contributor toeutrophication in some Gulf of Mexico estuaries;however, the relative roles of nitrogen and phospho-rus need clarification. The experts also called forbetter understanding of individual estuaries’ assimi-lative capacity, and more research on inlet circula-tion and approaches to inlet management.

In Florida Bay, this macroalgae bloom smothered the surrounding submerged aquatic vegetation.Photograph courtesy of Brian LaPointe, Harbor Branch Oceanographic Institute.


36

Pacific

12

3

4

56

7

8

9

1011

12

13

14

15

1. Tijuana Estuary2. San Diego Bay3. Mission Bay4. Newport Bay5. San Pedro Bay6. Alamitos Bay7. Anaheim Bay8. Santa Monica Bay9. Morro Bay10. Monterey Bay11. Elkhorn Slough12. San Francisco Bay13. Central San Francisco/ San Pablo/Suisun Bays14. Drakes Estero15. Tomales Bay16. Eel River17. Humboldt Bay18. Klamath River19. Rogue River20. Coquille River

21. Coos Bay22. Umpqua River23. Siuslaw River24. Alsea River25. Yaquina Bay26. Siletz Bay27. Netarts Bay28. Tillamook Bay29. Nehalem River30. Columbia River31. Willapa Bay32. Grays Harbor33. Puget Sound34. Hood Canal35. Whidbey Basin/Skagit Bay36. South Puget Sound37. Port Orchard System38. Bellingham/Padilla/Samish Bays39. Sequim/Discovery Bays

16

17

18

19

20212223242526272829

3031

32

33

35

34

36

37

3839


?

?

?

???

???

????

Pacific


High eutrophic conditions occur in the extreme north and south of the region, and on the central California coast.These estuaries tend to have restricted circulation and high nutrient inputs. Symptoms are expected to develop orworsen in the majority of systems, primarily due to projected population increases and development pressures.Estuarine habitats and shellfisheries are the most affected resources. In general, the most important nutrientsources for management concern are agriculture, forestry, wastewater treatment plants, and urban runoff. Theassessment confidence is generally low, except in San Francisco Bay and Puget Sound.








37

PacificFigure 28. Eutrophic conditions and symptomsThe Pacific region includes 39 estuaries, encompassing

more than 2,750 square miles of water surface area. Theregion consists of a relatively straight and uninterruptedshoreline with rocky shores, sandy beaches and occasionalriver outlets. Limited areas of flat, lowland environmentssupport estuaries, bays and lagoons. Estuaries are typi-cally small and separated by large distances. Estuarinecirculation patterns are dominated mainly by seasonalfreshwater inflow in Southern California and by fresh-water inflow and tides in the larger estuaries of centralCalifornia and Washington state. The tidal range is mod-erately high (5.0-7.5 feet). Forestry, agriculture and in-dustry are the dominant land uses in the region’s water-sheds. Some of the major population centers include LosAngeles, San Diego, San Francisco and Seattle.

Eutrophic ConditionsOverall Conditions. Pacific Coast estuaries exhib-ited a wide range of eutrophic conditions. High-levelconditions occurred in seven estuaries, mainly in thenorthern and southern sections of the region (Fig-ure 29). Among these were Tijuana Estuary, New-port Bay, and San Francisco Bay. Eleven estuariesfell into the moderate range; these were interspersedthroughout California and the Pacific Northwest.Nine estuaries were relatively unaffected byeutrophic conditions.

Expression of Symptoms. In 19 estuaries, at leastone of the six individual symptoms was expressedat high levels. Of the primary symptoms, chlorophylla was expressed at high levels in 11 systems, most ofthem in Southern California and northern Washing-ton. Macroalgal abundance was observed at moder-ate to high levels in 13 estuaries, most of them alsofound in Southern California and Washington. Epi-phyte abundance was minimal. Eight estuaries ex-hibited losses in submerged aquatic vegetation; twoof these at high levels. Nuisance/toxic algal bloomsoccurred in 21 estuaries, 12 of which were in themoderate to high range.

In general, the symptoms contributing most to higheutrophic conditions were elevated levels of chloro-

The Pacific region, more than anyother, is characterized by insufficientdata. Although the estuaries with un-known conditions are generally per-ceived to have few eutrophic prob-lems, many have moderate suscepti-bility and are predicted to developeutrophic symptoms by 2020.

Eut

roph

ic

Con

ditio

n

Symptom Expression

Chl

orop

hyll

a

Epi

phyt

es

Mac

roal

gae

SA

V L

oss

Low

Dis

solv

edO

xyge

n

Nui

sanc

e/T

oxic

Blo

oms

Estuary

Tijuana Estuary

Mission Bay

Newport Bay

San Pedro Bay

Monterey Bay

Elkhorn Slough

San Francisco Bay

Central San Francisco/San Pablo/Suisun Bays

Eel River

Humboldt Bay

Klamath River

Yaquina Bay

Columbia River

Willapa Bay

Puget Sound

San Diego Bay

Alamitos Bay

Anaheim Bay

Santa Monica Bay ?

Morro Bay

Drakes Estero ?

Tomales Bay

Rogue River ?

Coquille River ?

Coos Bay ?

Umpqua River ?

Siuslaw River ?

Alsea River ?

Siletz Bay ?

Netarts Bay ?

Tillamook Bay ?

Nehalem River ?

Grays Harbor

Hood Canal

Whidbey Basin/Skagit Bay

South Puget Sound

Port Orchard System

Bellingham/Padilla/Samish Bays

Sequim/Discovery Bays

? ?

?

? ?

? ? ?

? ?

? ? ?? ?

?

? ? ? ?

? ??

?

? ? ? ?

? ? ?

? ? ?

? ? ? ? ?

? ? ?

? ? ?

? ? ?

?

? ? ?

? ? ?

? ?

?

?

? ?

Primary Secondary

No Expression


?

ImprovingSymptom


38

PacificFigure 29. Eutrophic conditions and influencing factorsphyll a, coupled with various combinations of

macroalgal abundance, nuisance/toxic algal blooms,and low dissolved oxygen. High chlorophyll a con-centrations is also a fairly common natural condi-tion in some North Pacific estuaries due to naturallyoccurring seasonal blooms.

Recent improvements in certain symptoms were pri-marily attributed to point source controls and hy-drologic changes.

The confidence levels for the assessment of eutrophicconditions was generally low in this region. Of the27 estuaries that were characterized, 11 had low con-fidence levels. Twelve estuaries, most of them in Or-egon, had insufficient data for an assessment of con-ditions. Part of the reason for the paucity of data,however, is that eutrophication generally is not per-ceived to be a problem in these systems.

Overall Human InfluenceIn general, estuaries with high-level eutrophic con-ditions also had high levels of human influence (Fig-ure 30). Human influence on the expression ofeutrophic symptoms was most pronounced in theTijuana Estuary, Newport Bay, San Pedro Bay, Ana-heim Bay and San Francisco Bay. Three of these—Newport, Anaheim and San Pedro—are among thetop 10 U.S. estuaries with respect to population den-sity in the watershed. Tijuana Estuary is also notablebecause three-quarters of the watershed is locatedin Mexico, making management an internationalchallenge. The Tijuana River is the primary sourceof freshwater to the estuary; it is also a source ofuntreated sewage from the city of Tijuana.

Although 12 estuaries had insufficient data for anassessment of eutrophic conditions, these systemswere generally small, with good flushing capabili-ties, and nutrient loading appeared to be moderate.In general, restricted circulation and moderate tohigh levels of nutrient inputs were noted as the prin-ciple factors contributing to elevated eutrophicsymptoms in Pacific Coast systems.

The level of confidence in the assessment of overallhuman influence was low for 30 estuaries.

Impaired UsesThe uses most often cited as impaired were fishing,shellfishing, swimming and aesthetic value. Most ofthese responses addressed the estuaries of SouthernCalifornia and Washington; impaired uses were un-known in Oregon and northern California.

Eut

roph

ic

Con

ditio

n

Moderate Low

Sus

cept

ibili

ty

Nitr

ogen

Inpu

t

Ove

rall

Hum

an

Influ

ence

Insufficient Data

Estuary

High ?

?

?

Tijuana Estuary

Newport Bay

San Francisco Bay

Elkhorn Slough

Tomales Bay

Hood Canal

South Puget Sound

Port Orchard System

Anaheim Bay

San Diego Bay

Morro Bay

Whidbey Basin/Skagit Bay

Bellingham/Padilla/Samish Bays

Sequim/Discovery Bays

Willapa Bay

Grays Harbor

Puget Sound

Central San Francisco/San Pablo/Suisun Bays

San Pedro Bay

Mission Bay

Humboldt Bay

Eel River

Monterey Bay

Yaquina Bay

Klamath River

Columbia River

Alamitos Bay

Santa Monica Bay

Drakes Estero

Coos Bay

Siuslaw River

Tillamook Bay

Rogue River

Alsea River

Netarts Bay

Nehalem River

Coquille River

Umpqua River

Siletz Bay ?

?

?

?

?

?

?

?

?

?

?

?

?

?

Influencing Factors


39

Pacific

Potential Management ConcernsPotential sources to target to improve conditions inWashington estuaries are wastewater treatmentplants, on-site animal operations, agriculture andforestry. In Southern California, wastewater treat-ment plants, urbanization, agriculture and forestrywere cited.

With the exception of three estuaries—San FranciscoBay, Central San Francisco Bay and the ColumbiaRiver—experts noted that reductions in nutrient in-puts would significantly improve water-quality con-ditions. Workshop participants also recommendedthat management efforts focus primarily on thecoastal portions of the watersheds.

Future Outlook to 2020Thirty-one estuaries were predicted to develop wors-ening conditions during the next 20 years. Five ofthese—Tijuana Estuary, San Diego Bay, Newport Bay,Hood Canal and South Puget Sound—are expectedto get much worse. The reported reason for worsen-ing conditions was increasing population pressuresalong most of the coast.

The level of confidence in the assessment of the fu-ture outlook was low for 24 (nearly two-thirds) ofPacific estuaries.

Data Gaps and Research NeedsThe estuaries of the Pacific Coast are predominantlyunderstudied, particularly in Oregon and in someareas of California. Thus, there is a need for baselinemonitoring of basic water-quality parameters inthese areas. In addition, research is needed to deter-mine the fate of nutrients and their eventual impactson primary production and human uses of the re-sources. If water quality is to be managed properlyin the presently pristine systems, as well as in thosewith insufficient data, a much better understandingis needed of the linkages between nutrient inputs,productivity and eutrophic symptoms.

A bloom of nuisance algae mars an estuary in the state of Washington. Photo courtesy of Puget Sound Water Quality Action Team.


40

Conclusions


41

Conclusions

The National Estuarine Eutrophication Assessment provides a picture of nutrient-enrichment related water quality condi-tions in the nation’s estuaries. These conclusions are based on data and information about water quality conditions, theinfluence of natural and human-related factors, estuarine use impairments, and management recommendations compiledfor 138 estuaries (>90% of U.S. estuarine surface area) and also for the Mississippi River Plume. The results, which werereviewed and synthesized by experts at a National Assessment Workshop, provide a comprehensive assessment of thelocation, magnitude, and consequences of eutrophication in the nation’s estuaries.

Eutrophic Conditions in EstuariesThe overall expression of eutrophic conditions was highin 44 (one-third) of the 138 estuaries studied, and mod-erate in an additional 40 estuaries. Thus, 84 estuaries—60% of those studied—exhibited moderate to higheutrophic conditions. Although the greatest numberof estuaries with pronounced problems were foundin the Gulf of Mexico and Middle Atlantic regions,estuaries showing high levels of eutrophic conditionswere found along all of the nation’s coasts. Further-more, it is important to note that the estuaries assessedas having a high expression of eutrophic conditionswere those that have been the best studied. In themany estuaries that are understudied or for whichvery little is known, eutrophication may be more se-rious than the limited data reveal.

Symptoms and Related Use ImpairmentsAbout 40 percent (58) of the nation’s estuaries show highlevels of chlorophyll a, epiphytes, or macroalgae, signsof the initial stages of eutrophication. In terms of theirimpacts on estuaries, the most important symptoms in-dicative of eutrophication are low dissolved oxygen, theloss of submerged aquatic vegetation, and blooms ofnuisance and toxic algae. More than half (82) of U.S.estuaries, representing 67% of the estuarine surface areastudied, had moderate to high expressions of at leastone of these symptoms. This finding is of concern be-cause these symptoms can have serious consequences,including negative impacts on commercial fisheries, theloss of recreational opportunities, and potential risks tohuman health.

The experts identified more than half of the studiedestuaries as having use impairments related toeutrophic conditions. The implications are serious andaffect not only the natural resources but also theeconomy and human health. The resource uses mostfrequently reported as being impaired were commer-cial fishing and shellfish harvesting. Recreational fish-ing, swimming, and boating, all of which contributeto tourism in coastal areas, were also reported as im-paired to some degree. The reported risks to humanhealth include the consumption of tainted shellfish,as well as direct skin contact or the inhalation/inges-tion of water during an active bloom of toxic algae.

High expressions of eutrophic conditions are ex-hibited in 44 estuaries, representing 40% of thetotal estuarine surface area studied.

High conditions occur in estuaries along allcoasts, but are most prevalent along the Gulfof Mexico and Middle Atlantic coasts.

Key Findings

82 estuaries, representing 67% of the surfacearea studied, exhibit moderate to high expres-sions of either depleted dissolved oxygen, lossof submerged aquatic vegetation, or nuisance/toxic algal blooms.

69 estuaries were identified by workshop par-ticipants as having human use impairments re-lated to eutrophication.

Compared to other impaired uses, commercial/recreational fishing and shellfisheries wereidentified as impaired for human use in thegreatest number of estuaries (43 and 46, respec-tively).

Key Findings

Conclusions


42

Conclusions

Influencing Factors on EutrophicationMost estuaries that showed high levels of eutrophic con-ditions were moderately to highly influenced by hu-man-related nutrient inputs (e.g., wastewater treatment,agriculture, urban runoff, atmospheric deposition). Ofthe 44 estuaries with high expressions of eutrophic con-ditions, 36 were assessed as being highly influenced byhuman activities despite relatively moderate nutrientinputs. Most of these estuaries were in the Gulf ofMexico, the Middle Atlantic, and the Pacific regions.Most of the 44 estuaries (86 %) also had moderate tohigh susceptibility to retaining nutrient inputs; that is,their unique physical characteristics made them vul-nerable to developing the symptoms of eutrophication.It follows that susceptibility is an important factor inthe expression of high eutrophic conditions, especiallywhen nutrient inputs are not extremely high. Further-more, of the 38 estuaries with a low expression ofeutrophic conditions, 10 had high susceptibility, sug-gesting that they are at risk of future degradation, ifhuman-related nutrient inputs increase.

Implications for ManagementThe assessment of eutrophic conditions and influencingfactors provides a basis for identifying priority estuariesneeding remedial and preventive management action. Thelevel of human influence is a factor in determining to whatdegree management actions can reduce or reverseeutrophic problems; if the major influence is natural, thenit is likely that little can be done, except to plan appropri-ately. If the major influence is human-related, then impactsmay be reduced with appropriate management actions.Therefore, in the 36 estuaries with high expressions ofeutrophic conditions and high human influence, conditionscan be moderated or reversed with appropriate manage-ment action. The success of these efforts depends in parton susceptibility; low susceptibility enhances the effective-ness of nutrient reductions by flushing or diluting nutri-ents at the same time that inputs are reduced, while highlysusceptible estuaries may require greater effort due to theirnatural tendency to retain nutrients.

Of the non-impacted estuaries, those with moderate to highsusceptibility are in need of preventive action because theyare most at risk of developing problems if nutrient inputsincrease. In contrast, the estuaries that have low overallexpressions of eutrophic conditions, low human influenceand low susceptibility may not benefit as much from man-agement action. In general, these estuaries are less suscep-tible to developing problems to begin with. Some estuar-ies, such as many of those in Maine, exhibit naturally highlevels of eutrophic symptoms, mostly due to toxic algalblooms. In these estuaries, however, reductions in nutrientinputs are not likely to greatly affect conditions. While theseestuaries should not be ignored, nutrient control is not ur-gent at the present time.

A high level of human influence is associatedwith 36 of the 44 estuaries (82%) with a highexpression of eutrophic conditions.

Only six of the 44 estuaries (14%) with high-level eutrophic conditions have correspondinghigh-level nitrogen inputs.

Of the 44 estuaries with high-level eutrophicconditions, more than half (25) exhibit a highsusceptibility to retaining nutrients.

Key Findings

The 23 estuaries with high expressions ofeutrophic conditions and high susceptibilitywill likely require greater management effortand longer response time for results than thoseestuaries with low susceptibility. These estu-aries represent approximately 10% of nationalestuarine surface area in the study.

There are 10 estuaries, representing 3% of thenational estuarine surface area studied, thathave low eutrophic conditions and high suscep-tibility. Of the non-impacted estuaries, theseare the most at risk of developing problems.

Key Findings


43

Conclusions

Future Outlook and Management ConcernsExperts at the National Assessment Workshop esti-mated that the severity and extent of eutrophic con-ditions would worsen in 86 (nearly two-thirds) ofthe studied estuaries and in the Mississippi RiverPlume during the next 20 years, during which timethe coastal population is expected to increase bymore than 10 percent. The estuaries most at risk arethose that presently do not show symptoms but arehighly susceptible to retaining nutrients and are lo-cated in watersheds in which significant populationgrowth is projected. Most of these estuaries are lo-cated in the South Atlantic and Gulf of Mexico re-gions. Only eight (6%) of 138 estuaries are expectedto improve unless more is done to resolve this per-vasive environmental problem.

There is reason for optimism that eutrophication effectscan be moderated or reversed. The predictions of futureoutlook may not have taken into account the effective-ness of management efforts presently being pursued butnot yet completely effective, and those presently plannedbut not yet implemented. There have been measurableimprovements in estuaries (e.g., Tampa Bay, Sarasota Bay,and parts of Chesapeake Bay) for which there are com-prehensive watershed nutrient reduction strategies inplace, and from which lessons can be learned. The im-provements are mainly a result of point source treatment.However, there is a continued need to further reducenutrient inputs in order to counteract the effects of ex-pected population growth and other factors that promotethe development of eutrophic problems. If further man-agement actions are implemented and better coordinatednow, it is possible that the future outlook will be morepositive.

Nutrient inputs from agriculture, wastewater treat-ment, urban runoff, and atmospheric depositionwere identified as the most important managementtargets. Agricultural nutrient sources were men-tioned as especially important for management con-sideration in the Pacific, Gulf of Mexico, and SouthAtlantic regions. Wastewater treatment plants wereidentified most often in the North Atlantic. In theMiddle Atlantic, agriculture and atmospheric depo-sition were equally recommended as sources requir-ing management. The participants also emphasizedthe importance of managing nutrient inputs from awatershed perspective. Management plans must alsotake into account human and natural factors, includingsources of nutrients as well as watershed alterations thataffect the delivery of nutrients (e.g., the loss of wetlands)to maximize the benefit from nutrient reductions.

Eutrophic conditions could worsen in 86 estu-aries by the year 2020 if projected developmentpatterns are realized.

Of the 86 estuaries projected to worsen, 43 ex-hibit only low to moderate eutrophic condi-tions.

Of particular concern, especially if human-re-lated nutrient inputs increase, are the 10 estu-aries with low eutrophic conditions and highsusceptibility.

All of the typical point and nonpoint pollu-tion sources were identified at the National As-sessment Workshop as important to target inorder to manage nutrient problems. There are,however, some regional differences in impor-tant nutrient sources (e.g., combined seweroverflows in the North Atlantic).

Key Findings


44

Conclusions

Data Gaps and Research NeedsAmong the most important data gaps highlightedby this assessment is the lack of information aboutthe levels of eutrophic symptoms and trends. Of 138estuaries, 39 (nearly 30%) were rated as “low confi-dence” for the assessment of eutrophic conditions.The factors leading to low confidence include oneor more unknown symptoms, poor spatial or tem-poral resolution of data, and the inclusion of infor-mation based on expert judgment and observationrather than data. An additional 17 estuaries (12%)have insufficient data to make any assessment at all.In general, better characterization is needed for ex-isting levels and trends of symptoms and of nutri-ent inputs, including estimators of inputs such asland use and population. This information is neces-sary to assess overall eutrophic conditions, to estab-lish baseline conditions, and to track the conditionof an estuary. It would be especially useful in evalu-ating the success of management actions. This in-formation is also needed to determine causal rela-tionships so that appropriate management strategiescan be implemented. Among the primary sourcesof human-related nutrient inputs, more data are par-ticularly needed for atmospheric and groundwa-ter contributions, which are not well known due tothe difficulties in obtaining accurate measurements.Additionally, better estimates of population growthare needed for future projections of water quality.

Research is also needed to improve scientists’ un-derstanding of the mechanisms involved in, and in-fluences on, the eutrophication process, such as thetriggering of toxic algal blooms. Better characteriza-tion of basic circulation patterns would increase un-derstanding of how nutrients are processed oncethey reach an estuary, and thus, the potential out-come in terms of eutrophication. Factors that affectnutrient delivery, such as weather patterns, land use,and dramatic changes in seasonal population den-sity due to tourism, should also be studied. Otherresearch should be directed toward understandingthe linkages between the expression of eutrophicsymptoms and the resulting impacts to biologicalresources and risks to human health.

Despite all of the monitoring and research doneto date, information and knowledge still is in-adequate in 48 estuaries (low confidence or in-adequate data for assessment). These estuariesrepresent approximately 25% of the estuarinesurface area studied.

All participants in the National Assessmentprocess agreed that research is needed to clarifythe linkages between eutrophication and im-pacts on estuarine resources, including fisher-ies, recreation and tourism, and risks to humanhealth.

The National Assessment process confirms thatmuch remains to be done to adequately charac-terize nutrient pressure on estuaries. Betterquantification is needed of total nutrient in-puts, inputs by source, and estimators of nutri-ent pressure (e.g., population and land use). At-mospheric and groundwater inputs are leastwell quantified.

Better characterization of physical factors isneeded, including basic circulation patterns, ef-fects of weather patterns, climate change,changing land use, and resultant effects on nu-trient delivery, circulation, and eutrophic con-ditions.

Other research needs include defining the rela-tionship between nutrient inputs and toxicblooms, better characterization of assimilativecapacity, and characterization of the effects ofseasonal population changes.

Key Findings


45

Toward A National Strategy

At present, there is not a comprehensive national strategy to address the potentially worsening problems of estuarine eutrophi-cation. However, the results from this Assessment can help provide an improved basis for setting national priorities for manage-ment, monitoring, and research. In combination with successes in individual estuaries, such as those recently reported forTampa and Sarasota Bays, these results can provide the information necessary to help guide the development of a comprehensivenational strategy to reduce problems where they are presently observed and protect the nation’s coastal waters from furtherdegradation.

Why is a National Strategy Needed?This National Assessment confirms that estuarineeutrophication is indeed a problem of national sig-nificance. It indicates that human-related nutrientsources, both nearby and far removed, are substan-tial contributors to eutrophic conditions within es-tuaries. Furthermore, many estuarine watershedscross the boundaries of states, requiring regional,subregional and interagency cooperation. Similarly,there are many important needs with regard to re-search, monitoring, and assess-ment that also call for a cogent na-tional strategy. In many instances, forexample, eutrophication research hasbeen conducted on a parochial andpiecemeal basis, which can impede therapid advance of scientific under-standing of the linkages betweeneutrophication and marine resources.

A national strategy is needed, espe-cially one that effectively integrateswatershed-specific approaches to as-sessment and management into acomprehensive approach.

How Can These Results BeUsed?National Assessment results can beused to help better focus national at-tention on existing and emerging pri-ority areas for action; i.e., management,monitoring, and research. The frame-work shown (Figure 30) can be usedto organize assessment results for thispurpose. In particular, estuaries thatare in serious condition should be pri-orities for management actions; thosein less serious condition, but at risk ofdeterioration, should be closely moni-tored, and efforts should be made toidentify preventive measures. In ad-dition, estuaries for which there is in-sufficient information should be tar-geted for basic monitoring and assess-ment activities.

The framework incorporates the overall eutrophiccondition of an estuary, its natural susceptibility toretain nutrients, and the level of nutrient inputs, tohelp set priorities for appropriate actions that willallow the most effective results given environmen-tal concerns and resource limitations. This processcan be considered environmental triage—necessarydue to limited resources—which allows the sortingof estuaries into groups based on their need for, or

Toward a National Strategy

Figure 30. A framework for developing a national strategy

Estuaries with No or Low symptoms

Impacted Estuaries - “Naturally Occurring”

Impacted Estuaries -Human Influenced Eutrophication

Moderate to High Susceptibility

Low Susceptibility

•Nutrient Management (reduce inputs)•Research

•Nutrient Management (reduce inputs)•Remediation (restore sea grasses, oyster beds, wetlands, etc.)•Research

•Research (linkages between nutrients and symptoms - e.g. harmful algal bloom research)

None to Low Secondary Symptoms

None to Low Primary Symptoms

Low Overall Eutrophic Conditions

Moderate to High Human Influence Nutrient Inputs

MANAGEMENT RESPONSEENVIRONMENTAL TRIAGE

Moderate to High Eutrophic Conditions

Low Human Influence

Unknown or Low Confidence in Susceptibility

•Susceptibility Research and Analysis

Considerations for Priority Setting and Actions Needed

Assessment of Eutrophic Condition and Human Influence

Assessment of Susceptibility

Unknown/Low Assessment Confidence

•Assessment of Eutrophic Condition

•Assessment of Nutrient Inputs

• Preventive Measures • Early Warning Monitoring

Moderate to High Susceptibility

Low Susceptibility

•Susceptibility Research and Analysis

•Preventive Measures•Early Warning Monitoring

“Naturally Occurring”Symptoms

Unknown or Low Confidence in Susceptibility

e.g. Toxic Blooms

Eutrophic ConditionsNutrient Inputs

priority need for basic assessments

requires more intensive effort

requires less intensive effort


46


Nutrient enrichment and associatedeutrophic conditions have been identi-fied as a critical problem in the nation’sestuaries for over three decades.

As the 20th century comes to a close, acogent and comprehensive nationalstrategy still remains elusive.

likely benefit from, treatment. By such sorting, aframework is created that allows for logical and ef-fective decisions on how to allocate limited manage-ment, monitoring, and research resources among alarge number of estuaries. Note that this is not theonly way that the National Assessment results mightbe used; this framework is offered as guidance forhow the information might be used in planning anational strategy.

ManagementThe national assessment indicates that eutrophicsymptoms are driven, in large measure, by human-related nutrient sources. However, the response of asystem to reductions in nutrient input is dependentupon its natural susceptibility in combination withthe level of nutrient input it receives. Thus, in themanagement of nutrient sources, no one nutrientcontrol strategy is likely to achieve the desired re-sults in all estuaries across the nation.

The proposed assessment framework provides abasis for distinguishing between the remediation ofsystems that are already impacted, and preventivemeasures in systems that are at risk due to potentialincreases in nutrient loading. Both are necessary forimproving and protecting the health of the nation’sestuaries, and the assessment results should be usedto guide appropriate management and remediationplans. For instance, different plans should be imple-mented for those estuaries that, although in seriouscondition, might be improved with additional man-agement effort; those in less serious condition but atrisk of worsening that should be closely monitoredand managed; and those for which a basic assess-ment is needed because there is presently insuffi-cient information to evaluate conditions. The selec-tion of priority estuaries for management actionwithin these groups should be based on the level ofeutrophic conditions, the influence of human activi-ties, and the natural sensitivity to nutrients, to as-sure the most effective results within the constraintsof limited resources. The national assessment pro-vides a heretofore unavailable capability to targetthe nation’s investments to control eutrophication.

Monitoring and ResearchSome of the most useful information that has beendeveloped while conducting this assessment is acomprehensive understanding of what is actuallyknown about the phenomenon called “eutrophica-tion,” how well it is known, and whether it is un-derstood well or not at all. When taken together, theassessment data base and framework provide a“working model” for designing and evaluating the

efficiency and effectiveness of alternative nationalstrategies for monitoring and research.

For example, there is a need to strike the right bal-ance between monitoring designed primarily to de-scribe spatial patterns or extent (e.g., EPA’s Environ-mental Monitoring and Assessment Program) andfixed, continuous monitoring that emphasizes tem-poral resolution (both short- and long-term) and thetracking of nutrients and eutrophic symptoms. Thedata base and framework can also be used to deter-mine how monitoring programs can be integratedacross scales (local, regional, national) and across me-dia (water, air, land).

The assessment results also reconfirm the need formonitoring programs that are capable of document-ing ephemeral or real-time changes in symptoms,such as day-to-night fluctuations in dissolved oxy-gen, as well as over long time frames. Observationalsystems, such as the Global Ocean Observing Sys-tem that is presently being developed, need to bepromoted and sustained.

Within the framework of research, the detail that theassessment provides on the perspective of estuariesas mixing zones between rivers and oceans is invalu-able for determining where to direct many researchefforts. For example, the results of this national as-sessment should provide useful input to the NationalResearch Council’s ongoing study of the causes andmanagement of coastal eutrophication, which willhelp to further identify key science needs.


47


Data sources referenced during the National Assessment Workshop

Data Sources

Ph

ysic

al a

nd

Hyd

rolo

gic

Ch

arac

teri

stic

sN

utr

ien

t In

dic

ator

s

NOAA, 1985. National Estuarine Inventory, Volume 1: Physical and Hydrologic Characteristics. National Ocean Service, Silver Spring, MD.Note: This information is now included as part of NOAA’s Coastal Assessment and Data Synthesis System (CA&DS) and can be accessed at http://cads.nos.noaa.gov.

NOAA. 1993. Tide Tables 1993, High and Low Water Predictions. National Ocean Service, Silver Spring, MD

USGS, not dated. Water Resources Data. Gaged Streamflow Data. Water Resources Division, Reston, VA.

Smith, et al., 1997. Spatially Referenced Regressions on Watershed Attributes (SPARROW). In: Regional Interpretation of Water Quality Monitoring Data. Water Resources Research, Vol 33, No. 12, pp. 2781-98

USDA, 1987 and 1992. Census of Agriculture. CD-ROMs for 1987 and 1992.

USGS, 1990. County Level Estimates of Nitrogen and Phosporus Fertilizer Use in the US 1945-85. In: Alexander and Smith, 1990. USGS Open File Report 90-130.

US EPA, 1990 and J. Fletcher 1992 (written comm., U West VA). County Level Estimates of Nitrogen Fertilizer Sales in the Conterminous US 1986-91. In: Alexander and Smith, 1990. USGS Open File Report 90-130.

USGS, various dates. Land Use and Land Cover (LUDA).

US Bureau of the Census, undated. 1970 and 1990 population estimates. Population Estimates Program, Population Division. Washington, DC.

NPA Data Services, Inc, 1988. Key Indicators of County Growth 1970-2010. Washington, DC.

Estuary Boundaries and Water Surface Areas

Estuarine Salinity Zones

Estuary Average Depth

Estuary Volume

Watershed Boundaries (EDAs & FDAs) and Land Surface Areas

Vertical Stratification

Freshwater Inflow

Dilution Potential

Flushing Potential

Susceptibility: Estuarine Export Potential (EXP)

Tide Range

NOAA. 1998. Coastal Assessment and Data Synthesis System. National Ocean Service, Silver Spring, MD.

Nitrogen Loads (kg/yr)and Yields (kg/sq. mi/yr)

Nitrogen Trends from Livestock (1978-92)

Nitrogen Trends from Fertilizer Use (1970-91)

Cropland Area Trends (sq.miles) (1978-92)

Land Use (sq. miles)

Population (1970 and 1990)

Population (2010)

Soil Conservation Service, April, 1992, the Agricultural Waste Management Field Handbook, Chapter 4.


Eu

trop

hic

atio

nNOAA. 1998. NOAA’s estuarine eutrophication survey, vol. 5: Pacific Coast region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 75 pp.

NOAA. 1997. NOAA’s estuarine eutrophication survey, vol. 4: Gulf of Mexico region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 77 pp.

NOAA. 1997. NOAA’s estuarine eutrophication survey, volume 3: North Atlantic region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 46 pp.

NOAA. 1997. NOAA’s estuarine eutrophication survey, vol. 2: Mid-Atlantic region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 51 pp.

NOAA. 1996. NOAA’s estuarine eutrophication survey, vol. 1: South Atlantic region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 50 pp.



48


Appendix A: Methods

49

National Survey: Data Collection andSynthesisNOAA conducted three workshops in 1991-92 withlocal and regional estuarine scientists and coastal re-source managers. Two workshops held in January1991 consisted of presentations by invited speakersand discussions of the measures and effects associ-ated with nutrient problems. The purpose was tofacilitate the exchange of ideas on how to best char-acterize eutrophication in U.S. estuaries and to con-sider suggestions for the design of NOAA's pro-posed data collection survey. A third workshop, heldin April 1992, focused specifically on developingrecommendations for conducting a nationwide sur-vey.

Given the limited resources available for this project,it was not practical to try to gather and consolidatethe existing data records. Even if it were possible todo this, it would be very difficult to merge these datainto a comprehensible whole due to incompatibledata types, formats, time periods, and methods. Al-ternatively, NOAA elected to systematically acquirea consistent and detailed set of qualitative data fromthe existing expert knowledge base (i.e., coastal andestuarine scientists) through a series of surveys, in-terviews, and regional workshops. Based on theworkshops and additional meetings with experts,NOAA identified information requirements for a setof parameters which could be used to characterizeestuarine nutrient enrichment and eutrophication

This appendix describes the methodology used in the National Eutrophication Survey and the National Estuarine Eutrophi-cation Assessment. The survey process was used to establish a database of current (ca. 1995) eutrophication conditions andtrends (ca. 1970-1995) for all coastal regions of the coterminous United States. The National Assessment is an aggregationand interpretation of the Eutrophication Survey data plus additional assessments of human influence, future outlook,impaired uses, potential management concerns, and data gaps and research needs.

conditions. To be included in the survey, a param-eter had to be (1) essential for accurate characteriza-tion of nutrient enrichment related phenomena; (2)generally available for most estuaries; (3) compa-rable among estuaries; and (4) based upon existingdata and/or knowledge (i.e., no new monitoring oranalysis required).

The next step was to establish response ranges foreach parameter to ensure discrete gradients amongresponses. For example, the survey asked whethertotal dissolved nitrogen in the water column is high,medium, or low based upon specific thresholds(High ≥ 1 mg/l, Medium ≥ 0.1 < 1 mg/l, low > 0<0.1 mg/l, or unknown). The ranges were deter-mined from reviewing nationwide data and fromdiscussions with eutrophication experts. The thresh-olds used to classify ranges are designed to distin-guish conditions among estuaries on a national ba-sis.

Data Collection Framework. For each parameter,information was collected for existing conditions andrecent trends (circa 1970-1995). Existing conditionsdescribe maximum parameter values observed overa typical annual cycle (e.g., normal freshwater in-flow, average temperatures, etc.). For instance, fornutrients, information was collected characterizingpeak concentrations observed during the annualcycle such as those associated with spring runoffand/or turnover. For chlorophyll a, information wascollected on peak concentrations that are typically

reached during a bloom period.Additional information describ-ing the timing and duration ofexisting conditions was col-lected.

SurveyDesign

testing, review

National Survey

next steps workshop

Site Visits

Assessment Workshops

Regional Reports

Eutrophication Survey Process

Appendix A: Methods


Appendix A: Methods

50

Eutrophication Survey Parameters

CHLOROPHYLL A

TURBIDITY

SUSPENDED SOLIDS

NUISANCE ALGAE

TOXIC ALGAE

MACROALGAE

EPIPHYTES

NITROGEN

ANOXIA (0 mg/l)

HYPOXIA (>0mg/l ≤ 2mg/l)

BIOL. STRESS (>2mg/l ≤ 5mg/l)

PRIMARY PRODUCTIVITY

PLANKTONIC COMMUNITY

SUBMERGED AQUATIC VEG.

INTERTIDAL WETLANDS

EXISTING CONDITIONS TRENDS

Hypereutrophic (>60 µg chl-a/l) High (>20, ≤60 µg chl-a/l)Medium (>5, ≤20 µg chl-a/l) Low (>0, ≤5 µg chl-a/l)

• Surface concentrations:

• Limiting factors to algal biomass (N, P, Si, light, other)

• Spatial coverage1, Months of occurrence, Frequency of occurrence2

• Secchi disk depths:

High (<1m), Medium (1≥m, ≤3m), Low (>3m), Blackwater area

• Concentrations3,4

• Concentrations:

Problem (significant impact upon biological resources)No Problem (no significant impact)

• Months of occurrence, Frequency of occurrence2

• Occurrence

• Dominant species

• Event duration (Hours, Days, Weeks, Seasonal, Other)

• Abundance

• Maximum dissolved surface concentration:

High (≥1 mg/l), Medium (≥0.1, <1 mg/l), Low (≥0, < 0.1 mg/l)

High (≥0.1 mg/l), Medium (≥0.01, <0.1 mg/l), Low (≥0, < 0.01 mg/l)

• Dissolved oxygen condition

(Surface, Bottom, Throughout water column)

(High, Medium, Low, Not a factor)• Stratification (degree of influence):

• Water column depth:

• Dominant primary producer:

Pelagic, Benthic, Other

• Temporal shift

• Dominant taxonomic group (number of cells):

Diatoms, Flagellates, Blue-green algae, Diverse mixture, Other

Crustaceans, Molluscs, Annelids, Diverse mixture, Other

• Temporal shift

BENTHIC COMMUNITY• Dominant taxonomic group (number of organisms): • Temporal shift

PARAMETERS

PHOSPHORUS

• Maximum dissolved surface concentration:

• Spatial coverage1, Months of occurrence

• Limiting factors

• Contributing factors5



• Event duration3,4

• Frequency of occurrence3,4


• Abundance3,4






• Min. avg. monthly bottom dissolved oxygen conc.3,4

• Frequency of occurrence3,4

• Event duration3,4

• Spatial coverage3,4





• Spatial coverage3,4


NOTES

(1) SPATIAL COVERAGE (% of salinity zone): High (>50, ≤100%), Medium (>25, ≤50% ), Low (>10, ≤25%), Very Low (>0, ≤10% ), No SAV / Wetlands in system

(2) FREQUENCY OF OCCURRENCE: Episodic (conditions occur randomly), Periodic (conditions occur annually or predictably), Persistent (conditions occur continually throughout the year)

(3) DIRECTION OF CHANGE: Increase, Decrease, No trend

(4) MAGNITUDE OF CHANGE: High (>50%, ≤100%), Medium (>25%, ≤50%), Low (>0%, ≤25%)

(5) POINT SOURCE(S), NONPOINT SOURCE(S), OTHER




• Spatial coverage1, Months of occurrence


• Spatial coverage1

(maximum values observed over a typical annual cycle) (1970 - 1995)

(no trends information collected)


ObservedNo Occurrence

ALG

AL

CO

ND

ITIO

NS

NU

TR

IEN

TS

DIS

SO

LVE

D O

XY

GE

NE

CO

SY

ST

EM

/ C

OM

MU

NIT

Y R

ES

PO

NS

E



Appendix A: Methods

51

NOAA's National Estuarine Inventory (NEI) wasused as a spatial framework to collect and organizeinformation. Each parameter was characterized forthree salinity zones as defined in the NEI (tidal fresh0-0.5 ppt, mixing 0.5-25 ppt, and seawater >25 ppt),providing a consistent basis for comparisons amongthe estuarine systems.

Data Collection. Survey forms designed to collectinformation on 16 parameters related to nutrient en-richment and eutrophication were mailed in 1993 toover 400 experts who had agreed to participate inthe survey. The response rate was approximately 25percent with at least one response for 112 of the 129estuaries being surveyed. The survey methods and

Regional Workshop Assessment Review Process

Part 3

• –––––––• –––––––• –––––––• –––––––• –––––––

Part 2

• –––––––• –––––––• –––––––• –––––––• –––––––

Estuary 1 Salinity Zone Considerations

Part 1

• –––––––• –––––––• –––––––• –––––––• –––––––

question 1 question 2 question 3

Not Answerable

Notes

Consensus

Next Part

Next Estuary

Part 1

Spatial Framework Example

initial results were evaluated in May 1994 by a panelof NOAA, state, and academic experts. The panelrecommended that NOAA proceed with a regionalapproach for completing data collection, includingsite visits with selected experts to fill data gaps, re-gional assessment workshops to finalize and reachconsensus on the responses to each question, andregional reports on the results. Estuaries were tar-

geted for site visits based upon the completenessof the data received from the original mailed sur-vey forms. The new information collected fromsite visits was incorporated into the project database and summary materials were then preparedfor regional workshops.

Workshop participants included local and re-gional experts (at least one per estuary represent-ing the group of people with the most extensiveknowledge and insight about an estuary). In gen-eral, these persons had either filled out a surveyform and/or participated in a site visit. Prepara-tions included sending all regional data to par-ticipants prior to workshops. Participants werealso encouraged to bring to the workshops rel-evant data and reports. During the workshops,NOAA staff facilitated a careful discussion andreview of the survey data and salinity maps foreach estuary and recorded the results accordingly.

Participants were also asked to rank the reliabil-ity as either highly certain or speculative infer-ence, reflecting the robustness of the data the re-sponse is based on. This is especially importantgiven that responses are based upon a range of

information sources from statistically tested moni-toring data to general observations. Following theworkshops, results were summarized for review byworkshop participants. The information was thencompiled into regional reports that were also re-viewed by participants prior to publication.


Appendix A: Methods

52

Analysis of Data Completeness andReliability (DCR)The estuarine eutrophication survey is a compila-tion of information for 16 water quality parametersthat are related to nutrient enrichment. These pa-rameters, in various combinations and at specificlevels, are reflections of eutrophic conditions. Foreach of these parameters, information on charac-teristics of timing, duration, spatial coverage, andfrequency of occurrence was also collected as ap-propriate. The robustness of this data set is affectedby two factors - missing data and data that arejudged to be based on speculative inference. Datagaps were created when respondents could not sup-ply information —either information was not avail-able or was of insufficient quality or quantity to give

a reasonable answer. Responses were deemed specu-lative when, in the respondents judgment, they werebased on either very limited data or general observa-tions. The extent of data gaps and speculative re-sponses is important because formulations developedto assess the rating of eutrophication status on a na-tional basis use combinations of the parameters andparameter characteristics. The power of these formu-lations to accurately discriminate among systems isreduced if they contain significant gaps or a high de-gree of speculative inferences.

Data completeness and reliability was defined as thepercent of the total area of the estuary for which therewas a known value that was considered highly cer-tain for each parameter. DCR was calculated as follows:

2. A rating based on the DCR score was assigned to each parameter and to the entire system as follows:

High = 75 - 100 %Medium = 50 - 74%Low = 0 - 49%

The entire estuarine system DCR value was then computed as the mean of the parameter DCRs.

Chlorophyll a Concentration * Spatial Coverage * Frequency * ReliabilityEpiphytes Concentration * Frequency * ReliabilityMacroalgae Concentration * Frequency * ReliabilityDissolved Oxygen** Concentration * Spatial Coverage * Frequency * ReliabilitySAV Direction of change * Magnitude *ReliabilityNuisance algae Concentration * Frequency * Duration * ReliabilityToxic algae Concentration * Frequency * Duration * Reliability

** (mean of Anoxia, Hypoxia, and Biological Stress

The DCR scores were used by participants at the National Assessment Workshop to help assign confidenceratings to the overall eutrophic conditions assessment of estuaries (see Appendix B).

Surf. Area (sq. mi.)

Concen-tration Reliability

Spatial Coverage Reliability

Freq-uency Reliability

Sum of DCR Area

Survey response 3 Low Highly

certain Not eval. Not eval. Not eval. Not eval. --

DCR value 3 1 1 1 1 1 1 3

Survey response 28.8 Medium Highly

certain High Spec-ulative Periodic Highly certain --

DCR value 28.8 1 1 1 0 1 1 0

Survey response 18.1 Unknown Unknown Unknown Unknown Unknown Unknown --

DCR value 18.1 0 0 0 0 0 0 0

49.9 -- -- -- -- -- -- 3System Total

Tidal Fresh

Mixing

Seawater

Salinity Zone

Note that the speculative reliability rating for the spatial coverage call in the mixing zone and theunknown call for chlorophyll a concentration in the seawater zone result in the areas of these zonesbeing zeroed out in the calculation. Note also that spatial coverage and frequency are not evaluatedwhen concentrations are low. Thus, the DCR value for this parameter for this estuary would be:

(3 (tidal fresh) + 0 (mixing) + 0 (seawater))/System Total = 3/49.9 = 0 .061

Thus the DCR in the example above would be rated Low (6.1%).

The following is an example of the DCR calculation of chlorophyll a for an estuary.

1. A DCR calculation was made for each estuary by using the following combinations of parameter characteristics:


Appendix A: Methods

53

The National AssessmentIn all, the eutrophication survey produced a data ar-ray containing over 40,000 data values (120-1,200/estuary). While providing the best possible resolu-tion of the problem, the array also represented a chal-lenge to interpret the data. NOAA worked with a“core group” of 15 scientists and managers who par-ticipated in the original data survey to develop andapply methods that best integrate the survey datafor each estuary. It seemed reasonable that eutrophi-cation symptoms and their time/space characteris-tics could be combined in a way that provided asingle categorical value to represent the status ofeutrophic conditions for each estuary. The assess-ment also included human influence, impaired usesof estuaries, nutrient management targets, futureoutlook, and data gaps and research needs.

The Eutrophication Model. The core group par-ticipated in two work sessions to develop and testseveral analytical and numerical methods. Ulti-mately, a single model was developed that mademaximum use of the survey data and best describedthe sequence and severity of eutrophication condi-tions. The model used six symptoms that were most



Problematic Epiphytic Growth

SAV Spatial Coverage

Diatoms to Flagellates

Benthic Dominance to Pelagic Dominance

AnoxiaHypoxiaBiological Stress

Nuisance Bloom Problems

Toxic Bloom Problems

Primary Symptoms

Secondary Symptoms




Loss of Submerged Aquatic Vegetation

SAV Spatial Coverage Trends


Algal Dominance Changes Harmful Algae

Increased Organic MatterDecomposition


External Nutrient Inputs

Eutrophication model used for National Assessment

directly related to nutrient inputs. Three primarysymptoms, algal abundance (using chlorophyll a asan indicator), epiphyte abundance, and macroalgaerepresent the first possible stage of water quality deg-radation associated with eutrophication. Althoughnitrogen and phosphorus concentrations in the wa-ter column are directly related to nutrient inputs,elevated concentrations do not necessarily indicatethat eutrophication symptoms are present. Likewise,low water column concentrations do not necessar-ily translate to no problems present. Thus, these werenot included as primary symptoms in the model.

In many estuaries, the primary symptoms lead tosecondary symptoms, such as submerged aquaticvegetation loss, nuisance and toxic algal blooms, andlow dissolved oxygen (anoxia and hypoxia). In somecases, secondary conditions can exist in the estuarywithout originating from the primary symptoms.This occurs, for instance, in many North Atlantic es-tuaries where toxic algal blooms are transported intothese systems from the coastal ocean.

Determining the Overall Eutrophic ConditionA numerical scoring system was developed to inte-

grate information from all six primary andsecondary symptoms to determine theoverall status of eutrophication symptomsin each estuary. This scoring system wasimplemented in three phases.

First, a single index value was computedfrom all primary symptoms. An average ofthe three symptoms was then made to pro-vide an overall score for the primary symp-toms.

Next, a single index value was computedfrom all secondary symptoms. The highestsecondary score of the three symptoms wasassigned to the estuary rather than takingan average. This was done because an estu-ary exhibiting high impacts from only oneof the conditions may be just as impactedas an estuary with all three symptoms.

Finally, the range of numeric scores assignedto primary and secondary symptoms weredivided into categories of high, moderate,and low. Primary and secondary scores werethen compared in a matrix so that overallcategories could be assigned to the estuar-ies. A detailed description of these threephases follows.


Appendix A: Methods

54

Chlorophyll a Level of Expression Determination

Concentration

Hypereutrophic

or

High

Spatial Coverage

High

Moderate

Low

Frequency

Periodic

Periodic

Periodic

EpisodicHigh

EpisodicModerate

Spatial coverage and frequency of occurrence are used to determine the level of expression for each salinity zone and are then aggregated up to the estuary level (See Estuary Aggregation Rules ).

Expression

High

High

Moderate

Moderate

High

THEN

Concentration

Medium

1

1

0.5

1

0.5

Very Low Periodic Moderate 0.5

Spatial Coverage

High

Moderate

Low/Very Low

Frequency

EpisodicHigh

EpisodicMod/Low/Very Low

High

Moderate

Low

Low

Moderate

1

0.5

0.25

0.5

0.25

Unknown Flag A 0.5

Unknown Flag A 0.5

Concentration

Low Low 0.25

Value

Expression

Expression

Any Frequency

Any Frequency

EpisodicLow/Very Low Low 0.25

Unknown Flag A 0.5

Unknown Flag A 0.5

Any SpatialCoverage

Spatial Coverage Frequency

Any Frequency

Concentration Spatial Coverage Frequency

Unknown Unknown UnknownNot included in calculation

at zone level

AND ANDIF

Periodic

Periodic

Periodic

Any SpatialCoverage

Any SpatialCoverage

Phase 1: Primary Symptoms Method Description. This method assesses the level of expression of chlorophylla concentrations, epiphyte abundance problems, and macroalgal abundance problems. The method uses onlythe survey information pertinent to each particular symptom to determine the level of expression. For chloro-phyll a, concentration, spatial coverage and frequency of occurrence are used; for epiphytes and macroalgae, thefrequency of occurrence of problem conditions was used.

Classification Criteria. The following is a set of decision rules which were applied to the eutrophication surveydata to determine the level of expression of the primary symptoms.


Appendix A: Methods

55

Flags A through C are used to identify components for which not enough data was available. In these cases, assumptionswere made based on conservative estimates that unknown spatial coverage is at least 10 percent of a zone, and thatunknown frequency is at least episodic.

Phase 1: Primary Symptoms Method, continued.

Epiphyte Problem Level of Expression DeterminationThe frequency of problematic epiphytic growth is used to determine level of expression at the salinity zone level and is then aggregated up to the estuary level (See Estuary Aggregation Rules).

Epiphyte Problems

Observed

High

Moderate

Frequency

Episodic

Unknown Flag B

Expression Value

1

0.5

0.5

Unknown UnknownNot included in calculation at zone level

Periodic

ANDIF THEN

Macroalgae Problem Level of Expression DeterminationThe frequency of problematic macroalgal growth is used to determine level of expression at the salinity zone level and is then aggregated up to the estuary level (See Estuary Aggregation Rules).

Macroalgae Problems

Observed

High

Moderate

Frequency

Episodic

Unknown Flag C

Expression Value

1

0.5

0.5

Periodic

Unknown UnknownNot included in calculation at zone level

ANDIF THEN

Estuary Aggregation Rules

For each symptom (chlorophyll a, epiphytes, and macroalgae), an area weighted expression value for each zone is determined. First the surface area of the salinity zone is multiplied by the symptom expression value for the zone and then divided by the surface area of the entire estuary to obtain an area weighted value for the zone. The area weighted values are then summed to obtain the estuary level of expression value for the symptom.

Estuary Expression Value

≥ 0 to ≤ 0.3>0.3 to ≤ 0.6>0.6 to ≤ 1

Level of Expression Category Assigned

LowModerateHigh

The level of expression of the primary symptoms for the estuary is determined by calculating the average of the three estuary level of expression values (chlorophyll a, epiphytes, and macroalgae).

The estuary is then assigned a category for Primary Symptoms as follows:

n= total number of zones in estuary

Az= surface area of a single zone

At= total surface area of estuary

Symbols:

At

A z∑i = 1

nExpression

Value= symptom level of expression value for estuary

1.

2.

3.


Appendix A: Methods

56

Low Dissolved Oxygen Level of Expression Determination

Spatial coverage and frequency of occurrence are used to determine level of expression at the zone level and are then aggregated up to the estuary level (See Estuary Aggregation Rules ).

Anoxia

Observed

Spatial Coverage

High

Moderate

Low

Frequency

Periodic

Periodic

Periodic

EpisodicHigh

EpisodicModerate/Low/Very Low

Expression

High

High

Moderate

Low

Moderate

Hypoxia

Observed

1

1

0.5

0.5

0.25

Very Low Periodic Low 0.25

Spatial Coverage

High

Mod

Low/Very Low

Frequency

Periodic

Periodic

Periodic

EpisodicHigh

EpisodicModerate/Low/Very Low

High

Moderate

Low

Low

Moderate

1

0.5

0.25

0.5

0.25

Unknown Flag A 0.25

Unknown Flag B 0.25

Biological Stress

Observed

Spatial Coverage

High

Moderate/Low /Very Low

Frequency

Periodic

Periodic

Episodic

Moderate

Low

Low

0.5

0.25

0.25

Unknown Flag C 0.25

Any Spatial Coverage

Value

Expression Value

Expression Value

Any frequency

Any frequency

Any frequency

AND ANDIF THEN

Phase 2: Secondary Symptoms Method Description. This method uses the same approach as used for theprimary symptoms in order to assess the level of expression of depleted dissolved oxygen (anoxia, hypoxia,biological stress), submerged aquatic vegetation decline, and nuisance/toxic blooms. The method uses the in-formation pertinent to each particular symptom to determine the level of expression. For depleted dissolvedoxygen, spatial coverage and frequency of occurrence were used; for submerged aquatic vegetation decline, themagnitude of change of the decline in spatial extent was used; for nuisance/toxic blooms, the duration of bloomevents and frequency of occurrence was used.

Classification Criteria. The following is a set of decision rules which were applied to the eutrophication surveydata to determine the level of expression for low dissolved oxygen conditions, submerged aquatic vegetationdeclines, and nuisance/toxic blooms.


Appendix A: Methods

57

Phase 2: Secondary Symptoms Method Description, continued.

Flags A through F are used to identify impacts for which not enough data was available for the components. In thesecases, assumptions were made based on conservative estimates that unknown spatial coverage is at least 10 percent ofthe zone, unknown duration is at least days, and unknown frequency is at least episodic.

Nuisance and Toxic Blooms Level of Expression Determination

Submerged Aquatic Vegetation (SAV) Loss Level of Expression Determination

The magnitude of loss of the decline is used to determine the level of expression at the zone level and is then aggregated up to the estuary level (See Estuary Aggregation Rules ).

SAV Loss

Observed

High

Moderate

Low

Magnitude of Loss

High

Moderate

Low

Unknown Flag D

Expression Value

1

0.5

0.25

0.25

ANDIF THEN

The duration of bloom events and frequency of occurrence is used to determine impact severity at the salinity zone level, and are then aggregated up to the estuary level (See Estuary Aggregation Rules).

S = seasonal, M = months, V = variable, W = weeks, D = days, WS = weeks to seasonal, WM = weeks to months, DW = days to weeks

FrequencyNuisance Blooms

Problem

Duration Expression

DW, V, W

D

Moderate

Low

Episodic

Unknown

M, WM, WS, S, PR Periodic High 1

Value

Periodic 0.5

Periodic 0.25

DW, V, W

D

M, WM, WS, S, PR

Episodic

Episodic

Moderate

Low

0.5

0.25

Low 0.25

Flag E 0.25

FrequencyToxic Blooms

Problem

Duration Expression

DW, W, V

D

Moderate

Low

Episodic

Unknown

M, WM, WS, S, PR Periodic High 1

Value

Periodic 0.5

Periodic 0.25

DW, W, V

D

M, WM, WS, S, PR

Episodic

Episodic

Moderate

Low

0.5

0.25

Low 0.25

Flag F 0.25

Any Frequency

Any frequency

ANDIF THENAND


Appendix A: Methods

58

Phase 3: Determination of the OverallLevel of Expression of Eutrophic Condi-tions. The primary and secondary symp-toms were next compared in a matrix to de-termine an overall ranking of eutrophic con-ditions for the estuary. The overall assess-ments were reviewed by experts at the Na-tional Assessment Workshop. In some caseschanges were made to these assessmentsbased on the experts knowledge of the es-tuary. For instance, if an estuary was nearthe borderline of moderate and moderatelyhigh, expert judgement may have been usedto move the category up or down based oncomparison with the condition of othersimilar estuaries in the area.

In this report low and moderate low aregrouped together as low; moderate high andhigh are grouped together as high.

Phase 2: Secondary Symptoms Method Description, Continued.

Interpretation and Review. At the NationalAssessment Workshop, experts reviewedeach primary and secondary symptom as-sessment for all 138 estuaries in the survey.In some cases changes were made to theseassessments based on the experts knowl-edge of the estuary. For instance, borderlineestuaries with values around 0.3 and 0.6were sometimes moved up or down a cat-egory level based on the experts knowledgeof recent conditions not reflected by theoriginal survey data.

OVERALL LEVEL OF EXPRESSION OF EUTROPHIC CONDITIONS

LOW

MODERATE

MODERATE LOW MODERATE HIGH

Moderate secondary symptoms indicate substantial eutrophic conditions, but low primary indicates other factors may be involved in causing the conditions.

Level of expression of eutrophic conditions is minimal.

High secondary symptoms indicate serious problems, but low primary indicates other factors may also be involved in causing the conditions.

Primary symptoms begining to indicate possible problems but still very few secondary symptoms expressed.

Primary symptoms high but problems with more serious secondarysymptoms still not being expressed.

Level of expression of eutrophic condtions is substantial.

Substantial levels of eutrophic conditions occurring with secondary symptoms indicating serious problems.

Primary symptoms high and substantial secondary symptoms becoming more expressed, indicating potentially serious problems.

High primary and secondary symptom levels indicate serious eutrophication problems.

MODERATE LOW HIGH

MODERATE MODERATE HIGH HIGH

Low Secondary Symptoms

Moderate Secondary Symptoms

High Secondary Symptoms

0 0.3 0.6 1

Low

Prim

ary

Sym

ptom

sM

oder

ate

Prim

ary

Sym

ptom

sH

igh

Prim

ary

Sym

ptom

s

0.3

0.6

1

n= total number of zones in estuary

Az= surface area of a single zone

At= total surface area of estuary

Symbols:

At

A z∑i = 1

nExpression

Value

symptom levelof expressionvalue for estuary

=

For each symptom (anoxia, hypoxia, biological stress, submerged aquaticvegetation loss, nuisance blooms, toxic blooms), an area weighted expres-sion value for each zone is determined. First the surface area of the salinityzone is multiplied by the symptom expression value for the zone and thendivided by the surface area of the entire estuary to obtain an area weightedvalue for the zone. The area weighted values are then summed to obtainthe estuary level of expression value for the symptom.

The level of expression of the secondary symptoms for the estuary is de-termined by choosing the highest of the three estuary level symptom ex-pression values (depleted dissolved oxygen, submerged aquatic vegeta-tion loss, and nuisance/toxic blooms). For dissolved oxygen the highestvalue is chosen from the anoxia, hypoxia, or biological stress values. Forblooms the highest value is chosen from the nuisance or toxic bloom val-ues.

The estuary is then assigned a category for Secondary Symptoms as follows:

1.

2.

3.

Expression Value

≥ 0 to ≤ 0.3 >0.3 to ≤ 0.6>0.6 to ≤ 1

Level of Expression Category Assigned

LowModerateHigh

Estuary Aggregation Rules


Appendix A: Methods

59

IF: Vertical Stratification THEN: Dilution Volume IF: Dilution Value Dilution Potential

Vertically Homogenous •all year•throughout estuary

Minor Vertical Stratification•navigation channels•upper estuary

Vertically Stratified•most of year•most of estuary

1 / VOLestuary

1 / VOLestuary

1 / VOLfwf

10-13

10-12HIGH

10-10

10-09

10-11 MODERATE

LOW

Number of Estuaries

30

63

45

Type

A

B

C(fwf = freshwater fraction)

Determining Overall Human InfluenceThis analysis was performed as an attempt to determinethe extent to which human activities have contributed tothe observed eutrophic symptoms and conditions. Theunderlying assumption is that any particular level ofnutrient input will have varying effects in different estu-aries due to varying levels of susceptibility to the nutri-ent inputs. Therefore, separate analyses of both suscepti-bility and nutrient inputs were made and then the resultsof each were combined to determine the overall level ofhuman influence.

Susceptibility: Determining the Estuarine Export Po-tential (EXP)Estuarine susceptibility to nutrients is dependent in largepart on the amount of time that nutrients entering a sys-

tem stay in the system before exiting the system. The es-tuarine export potential is a method, developed as partof NOAA’s Coastal Assessment and Data Synthesis sys-tem, to estimate relative determinations of this amountof time by defining the relative capacity of estuaries todilute and flush dissolved nutrient loads. The analysisuses physical and hydrologic data to define separately 1)a dilution rating and 2) a flushing rating. In both cases,the higher the rating, the greater the capacity to dilute orflush nutrient loads (conversely, lower ratings suggest agreater tendency to retain nutrient loads).

2. Decision Rules for FLUSHING Potential. This analysis assumes that a greater capacity to flush nutrientloads exists for estuaries that have large tide and freshwater influences.

Type Tide Range (ft) Freshwater Inflow/Estuary Volume Flushing Potential Number of Estuaries

1 macro (>6) large or moderate HIGH 12

2 21

3 meso (>2.5) large HIGH 15

4 meso (>2.5) MODERATE 16

5 meso (>2.5) small LOW 26

6 micro (<2.5) large 4HIGH

7 micro (<2.5) 13

8 micro (<2.5) 31LOW

and

and

and

and

and

and

and

and

(1000 to 10-02)

macro (>6) small (10-03, 10-04) MODERATE

(1000, 10-01)

moderate (10-02)

(10-03, 10-04)

(1000, 10-01)

moderate (10-02) MODERATE

small (10-03, 10-04)

1. Decision Rules for DILUTION Potential. This analysis assumes that a larger portion of the water column is poten-tially available to dilute nutrient loads in a vertically homogenous estuary than in a vertically stratified system. Theassumption is that for stratified systems, nutrients are most often retained in the upper portion (freshwater fraction) ofthe water column. In contrast, downward transport (more complete mixing) is likely in vertically homogenous sys-tems. Type B estuaries are generally vertically homogenous, although stratification is observed (confined) in narrownavigation channels or the extreme upper reaches of an estuary. In this case, nutrients are assumed to be dilutedthroughout the entire water column.


Appendix A: Methods

60

Combining Dilution Potential and Flushing Po-tential. By combining dilution and flushing com-ponents, an EXP is determined. Estuaries in the up-per left portion of the matrix generally have a highEXP that suggests an ability to dilute and flush nu-trient loads. Estuaries in the lower right portion sug-gest estuaries that lack the ability to dilute or flushnutrients, making them more susceptible to nutri-ent pollution.

Nutrient Inputs. In order to develop an understand-ing of the amount of nutrient inputs being deliv-ered to the estuarine systems from human activi-ties, nationally comparable data sets had to be de-veloped. Estimates of nitrogen and phosphorusloads from point, nonpoint, and atmospheric sourceswere developed for each estuarine watershed. TheUSGS' SPARROW (spatially referenced regressionsof contaminant transport on watershed attributes)model was used as the primary indicator of nitro-gen pressure. In addition, a host of other data setswere used as surrogate nutrient pressure indicatorsto help substantiate load estimates. These includedEPA's county level estimates of fertilizer sales, USGS'county level estimates of fertilizer use, USGS' LandUse/Land Cover, U.S. Census Bureau PopulationCensus, and U.S. Department of Agriculture Cen-sus of Agriculture (see Data Sources Table).

A brief description of the SPARROW model isprovided here, as this was the principal data setused to evaluate the extent of nitrogen pressurewith respect to the observed eutrophic symp-toms. Estimates of total nitrogen loads are pro-vided for five major nutrient source types: pointsources, fertilizer, livestock, atmospheric depo-sition, and nonpoint/nonagricultural. Data areavailable for all USGS 8-digit hydrologic cata-log units and are based on measurements froma national network of stream gaging stations(NASQAN) that operated during 1970-1988. Forthe purposes of the national workshop, NOAAaggregated data for the 8-digit units to the wa-tershed scale, though this may have overesti-mated actual loads to some estuaries. The mod-eled estimates provide a snapshot of conditionsduring the early-1980s and do not offer timeseries data.

Determination of the Overall Level of Human In-fluence. The susceptibility to retain nutrients andthe level of nitrogen inputs were compared in a ma-trix to determine an overall ranking of the overalllevel of expression of human influence on eutrophicconditions in the estuary.

Low Nutrient Input Moderate Nutrient Input High Nutrient Input

Hig

h S

usce

ptib

ility

Mod

erat

e S

usce

ptib

ility

Low

Sus

cept

ibili

ty

Symptoms observed in the estuary are likely predominantly naturally related or caused by human factors other than nutrient additions.

Symptoms observed in the estuary are predominantly naturally related or caused by factors other than nutrient additions.

Symptoms observed in the estuary may be naturally related or the high level of nutrient additions may cause problems despite low susceptibility.

Symptoms observed in the estuary are minimally to moderately related to nutrient inputs.

Symptoms observed in the estuary are moderately related to nutrient inputs.

Symptoms observed in the estuary are moderately to highly related to nutrient additions.

Even low nutrient additions may result in problem symptoms in these estuaries.

Symptoms observed in the estuary are moderately to highly related to nutrient additions.

Symptoms observed in the estuary are probably closely related to nutrient additions.

MODERATE

MODERATE

MODERATE HIGH

MODERATE HIGH

HIGH

MODERATE LOW

MODERATE LOWLOWLOW

OVERALL LEVEL OF HUMAN INFLUENCE

Hig

hM

oder

ate

Low

High Moderate Low

DILUTION Potential

FLU

SH

ING

Pot

entia

l

HIGH EXP. Estuary has capacity to dilute and flush nutrients

MODERATE EXP. Estuary has capacity to either dilute or flush nutrients

LOW EXP. Estuary does not have capacity to dilute or flush nutrients

ESTUARINE EXPORT POTENTIAL AND SUSCEPTIBILITY

Low Susceptibility

Low Susceptibility

Low Susceptibility

Moderate Susceptibility



High Susceptibility

High Susceptibility

High Susceptibility

Experts at the National Assessment Workshop re-viewed and, when appropriate, modified the sus-ceptibility or nutrient pressure assessments. Modi-fications were made based on higher quality dataavailable for some estuaries and expert knowledgeand judgement.


Appendix A: Methods

61

Determining Future OutlookThis analysis was performed as an attempt to de-termine the likelihood of whether conditions inan estuary will worsen, improve, or stay the sameover the next twenty years. In the analysis, nu-trient input changes are predicted to determinewhich direction conditions will move. The estua-rine susceptibility to nutrients is then used to de-termine the magnitude. Population projectionsare used as a primary indicator of the level offuture nutrient input changes. However, popu-lation projections are subject to unpredictablechanges. Therefore, experts at the National As-sessment Workshop were asked to make modifi-cations to the determinations of future nutrientchanges, based on their knowledge of plannedor likely changes that will take place in the es-tuarine basins that will affect the level of nutri-ents entering the system.

Identifying Impaired Uses and PotentialManagement ConcernsExperts at the National Assessment Workshop iden-tified impaired uses which they judged to be relatedto the expression of eutrophic conditions in the wa-ter body. These impaired uses included recreationaland commercial fishing, fish consumption, shellfish,swimming, boating, aesthetics, tourism, SAV andhabitat loss, and loss of assimilative capacity. Al-though this information is not supported by a com-prehensive data set, it does provide a rough pictureof the extent of problems stemming from eutrophicconditions. The experts also identified the point andnonpoint sources which they judged as most impor-tant to target for managing nutrients. These sourcesincluded wastewater treatment, combined seweroverflow, on-site waste disposal such as septic sys-tems, industrial discharge, large animal operations,urban runoff, agriculture, forestry practices, range-land use, atmospheric inputs, and aquaculture. Alsoevaluated were potential effectiveness of nutrient re-ductions and watershed focus areas. Although theseassessments were not based on a national data set,the expert evaluations are useful for gaining a firstorder understanding at the national level of whattypes and level of actions will be required to addresseutrophication.

Identifying Data Gaps and Research NeedsExperts at the National Assessment Workshop iden-tified data gaps and research needs for improvingthe assessment of the severity, human influence,impacts, and appropriate response to eutrophication

in estuaries. The experts used their experience andknowledge, in combination with data completenessand reliability analysis of the eutrophication surveyresults, to produce these findings.

Future Nutrient Pressures Decrease

No Change in Future Nutrient Pressures

Future Nutrient Pressures Increase

Hig

h S

usce

ptib

ility

Mod

erat

e S

usce

ptib

ility

Low

Sus

cept

ibili

ty

Nutrient related symptoms observed in the estuary will most likely remain unchanged.

Nutrient related symptoms observed in the estuary are likely to worsen only minimally.

Nutrient related symptoms observed in the estuary are likely to improve.


Nutrient related symptoms observed in the estuary are likely to substantially worsen.

Nutrient related symptoms observed in the estuary are likely to improve somewhat.


Nutrient related symptoms observed in the estuary are likely to substantially worsen.

FUTURE OUTLOOK FOR EUTROPHIC CONDITIONS

Nutrient related symptoms observed in the estuary are likely to improve substantially.

IMPROVE HIGH NO CHANGE WORSEN LOW

IMPROVE LOW

IMPROVE LOW

NO CHANGE

NO CHANGE

WORSEN HIGH

WORSEN HIGH


Appendix A: Methods

62

Data sources referenced during the National Assessment Workshop.P

hys

ical

an

d H

ydro

logi

c C

har

acte

rist

ics

Nu

trie

nt I

nd

icat

ors

NOAA, 1985. National Estuarine Inventory, Volume 1: Physical and Hydrologic Characteristics. National Ocean Service, Silver Spring, MD.Note: This information is now included as part of NOAA’s Coastal Assessment and Data Synthesis System (CA&DS) and can be accessed at http://cads.nos.noaa.gov.

NOAA. 1993. Tide Tables 1993, High and Low Water Predictions. National Ocean Service, Silver Spring, MD

USGS, not dated. Water Resources Data. Gaged Streamflow Data. Water Resources Division, Reston, VA.

Smith, et al., 1997. Spatially Referenced Regressions on Watershed Attributes (SPARROW). In: Regional Interpretation of Water Quality Monitoring Data. Water Resources Research, Vol 33, No. 12, pp. 2781-98


USGS, 1990. County Level Estimates of Nitrogen and Phosporus Fertilizer Use in the US 1945-85. In: Alexander and Smith, 1990. USGS Open File Report 90-130.

US EPA, 1990 and J. Fletcher 1992 (written comm., U West VA). County Level Estimates of Nitrogen Fertilizer Sales in the Conterminous US 1986-91. In: Alexander and Smith, 1990. USGS Open File Report 90-130.

USGS, various dates. Land Use and Land Cover (LUDA).

US Bureau of the Census, undated. 1970 and 1990 population estimates. Population Estimates Program, Population Division. Washington, DC.

NPA Data Services, Inc, 1988. Key Indicators of County Growth 1970-2010. Washington, DC.

Estuary Boundaries and Water Surface Areas

Estuarine Salinity Zones

Estuary Average Depth

Estuary Volume

Watershed Boundaries (EDAs & FDAs) and Land Surface Areas

Vertical Stratification

Freshwater Inflow

Dilution Potential

Flushing Potential

Susceptibility: Estuarine Export Potential (EXP)

Tide Range

NOAA. 1998. Coastal Assessment and Data Synthesis System. National Ocean Service, Silver Spring, MD.

Nitrogen Loads (kg/yr)and Yields (kg/sq. mi/yr)

Nitrogen Trends from Livestock (1978-92)

Nitrogen Trends from Fertilizer Use (1970-91)

Cropland Area Trends (sq.miles) (1978-92)

Land Use (sq. miles)

Population (1970 and 1990)

Population (2010)

Soil Conservation Service, April, 1992, the Agricultural Waste Management Field Handbook, Chapter 4.


Eu

trop

hic

atio

nNOAA. 1998. NOAA’s estuarine eutrophication survey, vol. 5: Pacific Coast region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 75 pp.

NOAA. 1997. NOAA’s estuarine eutrophication survey, vol. 4: Gulf of Mexico region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 77 pp.

NOAA. 1997. NOAA’s estuarine eutrophication survey, volume 3: North Atlantic region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 46 pp.

NOAA. 1997. NOAA’s estuarine eutrophication survey, vol. 2: Mid-Atlantic region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 51 pp.

NOAA. 1996. NOAA’s estuarine eutrophication survey, vol. 1: South Atlantic region. Silver Spring, MD: Office of Ocean Resources Conservation and Assessment. 50 pp.



Appendix B: Table of Results

63

This appendix contains results of the National Estuarine Eutrophication Assessment, including some information that is not provided elsewhere in thereport, i.e., overall primary and secondary assessments, nutrient reduction effectiveness, and the type of watershed focus. The data is also presented asdetermined at the Assessment Workshop, i.e., “moderate low” was not combined with “low,” nor was “moderate high” combined with “high.”Impaired uses are indicated by their assessment basis: highly certain, moderately certain, or reasonable inference.

Prim

ary

Sec

onda

ryIn

fluen

cing

Fut

ure

Impa

ired

Use

sP

oten

tial M

anag

emen

t Con

cern

s

Eutrophic Condition

Wastewater Treatment

Combined Sewer Overflow

On-site (septics, etc.)

Industry

Animal Operations

Urban Runoff

Agriculture

Forestry Activities

Rangeland Use

Atmosphere

Aquaculture

Other

Would Nutrient ReductionsImprove Conditions?

Watershed Focus

Rec./Comm. Fishing

Fish Consumption

Shellfish

Swimming

Boating

Aesthetics

Tourism

SAV/Habitat Loss

Assimilative Capacity

Expected Change (2020)

Confidence


Confidence

Susceptibility

Nitrogen Yield


SAV Loss

Nuisance/Toxic Blooms

Overall Secondary Level

Chlorophyll a

Epiphyte Abundance


Overall Primary Level

N -

non

e ob

serv

ed; L

- lo

w; M

L -

mod

erat

e lo

w; M

- m

oder

ate;

MH

- m

oder

ate

high

; H -

hig

h; U

- u

nkno

wn;

IH -

impr

ove

high

; IL

- im

prov

e lo

w; N

C -

no

chan

ge; W

L -

wor

sen

low

; WH

- w

orse

n hi

gh R

I - r

easo

nabl

e in

fere

nce;

MC

- m

oder

atel

y ce

rtai

n; H

C -

hig

hly

cert

ain;

WC

- w

ater

col

umn;

EN

TR

- e

ntire

wat

ersh

ed; E

DA

- e

stua

rine

drai

nage

are

a; F

DA

- fl

uvia

l dra

inag

e ar

ea

No

rth

A

tlan

tic

St.

Cro

ix R

iver

/Cob

scoo

k B

ayM

HM

HL

LH

LL

NH

HL

HL

MW

HM

HC

NO

WC

√E

nglis

hman

Bay

MH

MH

MN

HH

NU

MM

LM

HL

LN

CM

HH

CN

OW

C√

Nar

ragu

agus

Bay

MH

MH

MN

NM

NU

HH

LM

HL

LN

CM

HH

CN

OW

C√

Blu

e H

ill B

ayM

LM

LM

NN

MN

NL

LL

HL

LW

LM

HC

NO

U

Pen

obsc

ot B

ayL

MH

LN

NL

NU

NL

ML

MH

LM

NC

MH

NO

ED

A√

√M

usco

ngus

Bay

ML

LM

NN

ML

UL

LL

LL

MN

CM

HC

NO

ED

A√

Dam

aris

cotta

Riv

erM

HM

NN

MN

NM

MM

HM

MW

LM

MC

NO

WC

√S

heep

scot

Bay

MH

MH

MN

MM

LU

HH

ML

HM

MN

CM

HH

CN

OE

DA

Ken

nebe

c/A

ndro

scog

gin

Riv

ers

ML

HM

NN

ML

NN

LL

HL

MN

CM

HN

OU

√C

asco

Bay

MH

HM

LM

LL

MH

HM

LM

HL

LIL

MH

HC

UE

NTR

√√

√S

aco

Bay

MM

HL

UN

LL

UH

HL

MH

LL

NC

MR

IN

OE

NTR

√√

Gre

at B

ayM

MH

ML

MM

LN

LM

ML

MH

ML

WH

MH

MC

UFD

A√

√H

ampt

on H

arbo

r E

stua

ryM

LL

MN

NM

LN

NL

LM

LL

LW

LM

MC

NO

U√

Mer

rimac

k R

iver

UU

UU

UL

UM

UM

LM

LL

LN

CM

LU

U

Plu

m Is

land

Sou

ndM

LM

HM

NN

ML

NN

LM

HM

MH

WH

LU

FDA

√M

assa

chus

etts

Bay

MM

HM

NH

HN

LM

MM

MH

LH

WL

MH

HC

YE

SE

DA

√√

√B

osto

n H

arbo

rM

HH

MH

MH

ML

NL

MH

HM

HIL

MH

YE

SE

DA

√√

√C

ape

Cod

Bay

MM

HM

NL

ML

LL

MM

LH

ML

NC

HN

OE

NTR

√√

Mid

dle

A

tlan

tic

Buz

zard

s B

ayM

LH

ML

LL

LL

NL

ML

HM

LN

CH

UU

Nar

raga

nset

t B

ayM

LH

MN

LL

LL

MM

MH

HM

HN

CH

UU

Gar

dine

rs B

ayM

HH

MN

NM

LH

MH

ML

MM

LN

CM

HC

HC

HC

HC

HC

HC

YE

SE

NTR

√√

√Lo

ng Is

land

Sou

ndM

HH

HL

HH

ML

MM

MH

HH

MN

CH

HC

HC

HC

YE

SE

NTR

√√

√C

onne

ctic

ut R

iver

ML

LM

UU

ML

UN

LM

LM

MN

CL

UU

Gre

at S

outh

Bay

MH

HH

NN

HL

MM

MM

HH

LN

CH

HC

HC

HC

HC

YE

SE

NTR

√√

Hud

son

Riv

er/R

arita

n B

ayM

HH

LL

MM

NM

MM

HH

MH

NC

HH

CH

CM

CY

ES

EN

TR√

√√

Bar

nega

t B

ayH

HH

NH

HL

UH

HM

HH

HM

WL

HM

CY

ES

EN

TR√

New

Jer

sey

Inla

nd B

ays

ML

LM

NL

ML

UL

LM

HL

HM

WH

LU

U

Del

awar

e B

ayM

LH

MN

NM

LN

NL

MH

HM

HN

CH

UE

NTR

√√

Del

awar

e In

land

Bay

sH

HM

UH

HL

NH

HM

HM

HH

LN

CM

HC

MC

MC

HC

RI

YE

SE

NTR

√√

√M

aryl

and

Inla

nd B

ays

MM

HM

NM

LN

MM

MH

HL

WL

LR

IR

IR

IR

IY

ES

ED

A√

√C

hinc

otea

gue

Bay

ML

LM

UU

ML

NN

LM

LH

LW

LL

UU

Che

sape

ake

Bay

HH

HH

NH

HH

NH

HH

HM

WL

HR

IH

CH

CR

IY

ES

EN

TR√

√√

Pat

uxen

t R

iver

HH

HU

NH

MH

HH

MH

HH

MW

LH

RI

HC

RI

MC

YE

SE

NTR

√√

√P

otom

ac R

iver

HH

HU

LM

HM

MH

MH

HH

MW

LH

RI

HC

MC

YE

SE

NTR

√√

√R

appa

hann

ock

Riv

erM

HH

NN

MM

NN

MH

HH

MW

LH

RI

HC

MC

YE

SE

NTR

√√

√Y

ork

Riv

erM

HH

MN

NM

MM

NM

MH

HH

LW

HH

RI

HC

RI

MC

YE

SE

NTR

√√

√Ja

mes

Riv

erM

LH

HN

NM

LN

NL

MH

HM

MW

LH

RI

RI

YE

SE

NTR

√√

√C

hest

er R

iver

MH

MU

NM

LL

NL

MH

HH

MW

LH

RI

MC

YE

SE

NTR

√√

Cho

ptan

k R

iver

MH

MH

MH

LH

MH

MH

HH

MW

LH

RI

MC

YE

SE

NTR

√√

Tan

gier

/Poc

omok

e S

ound

sM

HH

HH

HH

LH

LM

HH

HH

WH

HH

CH

CH

CR

IU

EN

TR√




64

Prim

ary

Sym

ptom

sS

econ

dary

Sym

ptom

sIn

fluen

cing

Fac

tors

Fut

ure

Out

look

Impa

ired

Use

sP

oten

tial M

anag

emen

t Con

cern

s

Eutrophic Condition

Confidence




Industry

Animal Operations

Urban Runoff

Agriculture

Forestry Activities

Rangeland Use

Atmosphere

Aquaculture

Other


Watershed Focus

Rec./Comm. Fishing

Fish Consumption

Shellfish

Swimming

Boating

Aesthetics

Tourism

SAV/Habitat Loss



Confidence


Confidence

Susceptibility

Nitrogen Yield


SAV Loss



Chlorophyll a

Epiphyte Abundance



N -

non

e ob

serv

ed; L

- lo

w; M

L -

mod

erat

e lo

w; M

- m

oder

ate;

MH

- m

oder

ate

high

; H -

hig

h; U

- u

nkno

wn;

IH -

impr

ove

high

; IL

- im

prov

e lo

w; N

C -

no

chan

ge; W

L -

wor

sen

low

; WH

- w

orse

n hi

ghR

I - r

easo

nabl

e in

fere

nce;

MC

- m

oder

atel

y ce

rtai

n; H

C -

hig

hly

cert

ain;

WC

- w

ater

col

umn;

EN

TR

- e

ntire

wat

ersh

ed; E

DA

- e

stua

rine

drai

nage

are

a; F

DA

- fl

uvia

l dra

inag

e ar

ea

So

uth

A

tla

nti

c

Alb

emar

le S

ound

UU

LN

NL

LL

LL

ML

MM

WL

MN

OE

DA

√√

√P

amlic

o S

ound

UU

MN

NM

LL

MH

ML

MM

NC

MM

CY

ES

EN

TR√

√P

amlic

o/P

ungo

Riv

ers

MH

HH

NN

HM

MM

MM

HH

HM

NC

MH

CM

CR

IY

ES

EN

TR√

√√

Neu

se R

iver

HH

HN

NH

HL

HH

HH

HH

NC

MH

CM

CM

CH

CM

CM

CY

ES

EN

TR√

√√

Bog

ue S

ound

ML

MM

UN

MN

UL

LL

LH

LIL

MU

ED

A√

√√

New

Riv

erM

HM

HN

NH

LU

HH

MH

ML

MIL

MM

CR

IR

IM

CY

ES

EN

TR√

√√

Cap

e F

ear

Riv

erM

MH

NN

HL

UN

LM

LH

MN

CM

MC

RI

UE

NTR

√√

√W

inya

h B

ayM

LL

MN

NM

MN

NM

MM

MM

NC

MR

IN

OE

DA

√√

N.

San

tee/

S.

San

tee

Riv

ers

ML

LU

NN

LM

UN

MM

LM

ML

NC

MN

OU

Cha

rlest

on H

arbo

rM

HM

NM

MM

NN

MM

MM

MW

HM

HC

HC

YE

SE

NTR

√√

√S

tono

/Nor

th E

dist

o R

iver

sM

LM

UN

NL

MN

NM

MM

HL

NC

MN

OE

DA

√√

St.

Hel

ena

Sou

ndU

UL

UU

LM

UU

ML

ML

LIL

MN

OE

DA

√√

Bro

ad R

iver

ML

ML

UU

LM

UN

MM

LM

ML

WH

MN

OE

NTR

√√

√S

avan

nah

Riv

erM

MM

NN

MM

NN

LL

ML

MW

LM

HC

HC

NO

EN

TR√

√√

Oss

abaw

Sou

ndM

LL

MN

NM

LU

NL

LM

LL

MW

LM

NO

EN

TR√

√√

St.

Cat

herin

es/S

apel

o S

ound

sM

LL

MN

NM

LN

NL

ML

LM

LW

HM

NO

ED

A√

√A

ltam

aha

Riv

erM

LM

MN

NM

LN

NL

LM

MM

WL

MN

OE

NTR

√√

√S

t. A

ndre

w/S

t. S

imon

s S

ound

sM

LL

MN

NM

LN

NL

ML

LM

LW

HM

NO

ED

A√

√S

t. M

arys

R./C

umbe

rland

Snd

.M

LM

NN

MM

NN

LM

LL

ML

WH

MR

IN

OE

DA

√√

√√

St.

John

s R

iver

MH

LH

MN

HM

LL

MM

LH

LW

HL

UU

Indi

an R

iver

ML

MM

MM

MM

LM

ML

HL

WH

LU

U

Bis

cayn

e B

ayL

LL

NN

LL

NN

LU

UH

UW

HL

UU

Gul

f of

M

exic

o

Flo

rida

Bay

HM

HM

HH

HH

MM

HM

HL

MU

ILM

HC

HC

RI

RI

HC

HC

YE

SE

NTR

√√

√S

outh

Ten

Tho

usan

d Is

land

sM

HL

MN

NM

HL

NH

MH

LH

UW

LM

UU

Nor

th T

en T

hous

and

Isla

nds

MM

MN

NM

MU

NM

ML

HU

WL

LU

U

Roo

kery

Bay

ML

ML

NN

LL

NN

LM

LL

HU

NC

LU

U

Cha

rlotte

Har

bor

MH

MH

MN

MH

LM

HM

HM

HL

WL

MU

EN

TR√

√√

Cal

oosa

hatc

hee

Riv

erM

HM

HN

NH

LL

NL

MH

MM

MW

LM

RI

RI

MC

YE

SFD

A√

Sar

asot

a B

ayM

HH

MH

LM

MN

HM

MH

HM

HW

LM

RI

YE

SE

NTR

√√

√T

ampa

Bay

MH

HH

NN

HL

NM

MM

HH

MM

NC

MM

CM

CY

ES

EN

TR√

√√

Suw

anne

e R

iver

MM

MN

ML

LN

LL

ML

MM

LW

LM

NO

FDA

√√

√A

pala

chee

Bay

ML

LM

NN

ML

NM

MM

LL

ML

WL

LU

U

Apa

lach

icol

a B

ayM

HM

NN

MM

NM

MM

HH

MM

WL

MU

U

St.

And

rew

Bay

MM

ML

LL

MU

LM

ML

ML

WL

LY

ES

ED

A

Cho

ctaw

hatc

hee

Bay

MH

MM

HL

MM

MH

HM

HM

MM

WL

LR

IR

IY

ES

ED

A

Pen

saco

la B

ayM

MM

UU

MM

MN

MM

HM

MM

WL

LR

IY

ES

ED

A√

√P

erdi

do B

ayM

MM

NH

HM

NL

MM

HM

HM

WL

LR

IM

CY

ES

ED

A√

√M

obile

Bay

MM

MN

NM

ML

MM

MM

MM

NC

MH

CU

EN

TR√

√E

ast

Mis

siss

ippi

Sou

ndM

LM

NN

MM

ML

MM

LM

MN

CL

MC

UU

Wes

t M

issi

ssip

pi S

ound

ML

MM

LN

LL

ML

MM

MM

MN

CL

UU

H



65

Prim

ary

Sym

ptom

sS

econ

dary

Sym

ptom

sIn

fluen

cing

Fac

tors

Fut

ure

Out

look

Impa

ired

Use

sP

oten

tial M

anag

emen

t Con

cern

s

Eutrophic Condition

Confidence




Industry

Animal Operations

Urban Runoff

Agriculture

Forestry Activities

Rangeland Use

Atmosphere

Aquaculture

Other


Watershed Focus

Rec./Comm. Fishing

Fish Consumption

Shellfish

Swimming

Boating

Aesthetics

Tourism

SAV/Habitat Loss



Confidence


Confidence

Susceptibility

Nitrogen Yield


SAV Loss



Chlorophyll a

Epiphyte Abundance



N -

non

e ob

serv

ed; L

- lo

w; M

L -

mod

erat

e lo

w; M

- m

oder

ate;

MH

- m

oder

ate

high

; H -

hig

h; U

- u

nkno

wn;

IH -

impr

ove

high

; IL

- im

prov

e lo

w; N

C -

no

chan

ge; W

L -

wor

sen

low

; WH

- w

orse

n hi

ghR

I - r

easo

nabl

e in

fere

nce;

MC

- m

oder

atel

y ce

rtai

n; H

C -

hig

hly

cert

ain;

WC

- w

ater

col

umn;

EN

TR

- e

ntire

wat

ersh

ed; E

DA

- e

stua

rine

drai

nage

are

a; F

DA

- fl

uvia

l dra

inag

e ar

ea

Gul

f of

M

exic

o (c

ontin

ued)

Lake

Bor

gne

UU

UU

UL

NU

MM

ML

MM

NC

LU

U

Lake

Pon

tcha

rtra

inH

MM

HH

HL

HM

HH

MM

MW

HM

YE

SU

Bre

ton/

Cha

ndel

eur

Sou

nds

ML

LU

UN

LL

LN

LM

LL

ML

ILL

UU

Mis

siss

ippi

Riv

erM

LM

MN

NM

LN

NL

MH

LM

NC

MU

U

Bar

atar

ia B

ayM

MH

NN

HM

NL

MM

MM

MN

CM

UU

Ter

rebo

nne/

Tim

balie

r B

ays

MM

HN

NH

LU

LL

MM

HL

WL

MU

U

Atc

hafa

laya

/Ver

mil i

on B

ays

MM

HN

NH

LL

NL

MM

LL

NC

MU

U

Mis

siss

ippi

Riv

er P

lum

eH

HH

NN

HH

NH

HH

HU

UW

HM

UU

Mer

men

tau

Est

uary

LL

UN

NL

NN

NL

LL

MM

ILL

UU

Cal

casi

eu L

ake

HM

HN

NH

MM

HH

MH

MM

MW

LM

YE

SU

Sab

ine

Lake

MM

MN

NM

LN

LL

MH

MM

MN

CM

RI

YE

SE

DA

√√

√√

√G

alve

ston

Bay

MH

HM

NN

ML

HL

HM

HM

MM

WL

MH

CH

CH

CH

CH

CY

ES

ED

A√

√√

√√

Bra

zos

Riv

erM

MM

NN

LM

NL

MM

MM

LN

CM

RI

MC

RI

RI

YE

SE

DA

√√

√M

atag

orda

Bay

MM

MN

NM

LN

LL

MH

MH

LW

LM

MC

RI

YE

SE

DA

√√

√√

√√

√S

an A

nton

io B

ayM

HM

MH

HH

LL

LL

MH

MM

LW

LM

RI

RI

YE

SE

NTR

√√

√√

√A

rans

as B

ayM

MM

MH

ML

LL

LM

MH

MN

CL

RI

RI

RI

RI

YE

SE

NTR

√√

√√

Cor

pus

Chr

isti

Bay

HM

HH

HH

LN

HH

MH

MH

LW

HH

MC

RI

RI

YE

SE

DA

√√

√√

Upp

er L

agun

a M

adre

HH

HN

NH

MM

HH

HM

HM

WH

MM

CM

CM

CY

ES

ED

A√

√√

√B

affin

Bay

HL

HN

NH

LN

HH

HL

HM

WH

LM

CM

CM

CM

CY

ES

EN

TR√

√√

√√

√Lo

wer

Lag

una

Mad

reH

HH

NN

HL

MH

HH

MH

LW

HH

MC

MC

MC

MC

YE

SE

NTR

√√

√√

√√

Pa

cif

ic

Tiju

ana

Est

uary

HH

HN

HH

MN

LM

HH

HH

WH

HR

IR

IH

CH

CY

ES

ED

A√

San

Die

go B

ayM

LU

NH

HL

UL

LM

HL

HM

WH

LU

U

Mis

sion

Bay

ML

LL

NN

LN

NN

LM

HL

HM

WL

LU

U

New

port

Bay

HM

HH

NH

HH

ML

MH

HH

HW

HH

HC

HC

HC

HC

YE

SE

DA

√√

San

Ped

ro B

ayL

LL

NN

LN

NL

LH

LH

HW

LU

U

Ala

mito

s B

ayM

LL

UN

NL

MN

LM

UU

HU

UU

U

Ana

heim

Bay

MM

UN

HH

LU

LL

HM

HH

WL

MM

CM

CY

ES

EN

TR√

√S

anta

Mon

ica

Bay

UU

UU

LL

UN

LL

MH

LM

HN

CU

U

Mor

ro B

ayM

LU

UH

HL

HH

HM

HL

HM

NC

UU

Mon

tere

y B

ayM

LM

MN

NL

LN

MM

ML

ML

LL

WL

MU

EN

TR√

√E

lkho

rn S

loug

hM

HL

MH

HH

MN

MM

MH

LH

MN

CU

U√

√S

an F

ranc

isco

Bay

HH

HN

NH

LH

NH

HH

MM

WL

MN

OE

DA

√√

Cen

t. S

F./S

an P

ablo

/Sui

sun

Bay

sM

HM

NN

ML

MH

ML

HL

MN

CM

HN

OE

NTR

√√

√D

rake

s E

ster

oU

UU

UU

LU

UN

LM

HL

LM

WH

UU

Tom

ales

Bay

MH

LU

NN

LN

NH

HM

HL

HM

WH

UU

Eel

Riv

erL

LL

NN

LN

NN

LM

LM

MW

LU

U

Hum

bold

t Bay

LL

LN

NL

NN

NL

MH

LH

MN

CU

U

Kla

mat

h R

iver

LL

LN

NL

NN

NL

ML

LM

LN

CU

U

Rog

ue R

iver

UU

UU

UL

NL

UL

ML

MM

WL

LU

U

Coq

uille

Riv

erU

UL

UU

LN

NU

LM

LL

ML

WL

LY

ES

ED

A√



66

Prim

ary

Sym

ptom

sS

econ

dary

Sym

ptom

sIn

fluen

cing

Fac

tors

Fut

ure

Out

look

Impa

ired

Use

sP

oten

tial M

anag

emen

t Con

cern

s

Eutrophic Condition

Confidence




Industry

Animal Operations

Urban Runoff

Agriculture

Forestry Activities

Rangeland Use

Atmosphere

Aquaculture

Other


Watershed Focus

Rec./Comm. Fishing

Fish Consumption

Shellfish

Swimming

Boating

Aesthetics

Tourism

SAV/Habitat Loss



Confidence


Confidence

Susceptibility

Nitrogen Yield


SAV Loss



Chlorophyll a

Epiphyte Abundance



N -

non

e ob

serv

ed; L

- lo

w; M

L -

mod

erat

e lo

w; M

- m

oder

ate;

MH

- m

oder

ate

high

; H -

hig

h; U

- u

nkno

wn;

IH -

impr

ove

high

; IL

- im

prov

e lo

w; N

C -

no

chan

ge; W

L -

wor

sen

low

; WH

- w

orse

n hi

ghR

I - r

easo

nabl

e in

fere

nce;

MC

- m

oder

atel

y ce

rtai

n; H

C -

hig

hly

cert

ain;

WC

- w

ater

col

umn;

EN

TR

- e

ntire

wat

ersh

ed; E

DA

- e

stua

rine

drai

nage

are

a; F

DA

- fl

uvia

l dra

inag

e ar

ea

Pa

cifi

c (c

on

tin

ue

d)

Coo

s B

ayU

UM

MM

MN

NU

LM

LM

MW

LL

YE

SU

Um

pqua

Riv

erU

UL

UU

LN

UU

LM

LL

ML

WL

LU

U

Siu

slaw

Riv

erU

UM

UU

LL

NU

LM

LM

MW

LL

UU

Als

ea R

iver

UU

MU

UL

NN

UL

ML

MM

WL

LU

U

Yaq

uina

Bay

ML

HM

NN

ML

NN

LM

LL

ML

WL

LU

U

Sile

tz B

ayU

UU

UU

LN

UU

LM

LL

ML

WL

LU

U

Net

arts

Bay

UU

MU

UM

NN

UL

ML

HM

WL

LU

U

Till

amoo

k B

ayU

UL

UU

LN

NU

LM

LM

MW

LL

UU

Neh

alem

Riv

erU

UL

UU

LN

NU

LM

LM

MW

LL

UU

Col

umbi

a R

iver

ML

MH

NN

HN

NL

LL

ML

LL

NC

ML

NO

FDA

√W

illap

a B

ayM

MM

NH

HN

MM

MM

LM

LM

WL

MR

IR

IY

ES

ED

A√

√√

Gra

ys H

arbo

rM

MM

NH

HN

UM

MM

LM

LL

MW

LM

RI

RI

YE

SE

DA

√√

√P

uget

Sou

ndM

MH

NH

HL

LM

MM

LM

LM

WL

MM

CM

CM

CY

ES

ED

A√

√√

Hoo

d C

anal

MH

MH

UU

HM

UN

MM

HM

HL

WH

MH

MC

MC

YE

SE

DA

√√

√W

hidb

ey B

asin

/Ska

git

Bay

MM

HU

UH

LU

LL

MM

LM

MW

LM

RI

RI

YE

SE

DA

√√

√S

outh

Pug

et S

ound

MH

MH

UN

HL

UM

MM

HM

HM

WH

MH

MC

MC

MC

MC

YE

SE

DA

√√

√P

ort

Orc

hard

Sys

tem

MH

MH

UH

HL

LM

MM

ML

MM

WL

MR

IR

IY

ES

ED

A√

√√

Bel

lingh

am/P

adill

a/S

amis

h B

ays

MM

HU

MH

NN

MM

MM

LM

UW

LM

RI

RI

YE

SE

DA

√√

Seq

uim

/Dis

cove

ry B

ays

ML

HU

HH

LU

MM

MM

LM

UW

LM

RI

HC

YE

SE

DA

√√



67

The individuals listed here contributed to the creation of this report. A check mark for a survey form indicates that a participant filledout all or part of an initial data collection form for one or more estuaries. The regional assessment column indicates that the partici-pant was involved in site visits or attendance at regional assessment workshops. Individuals noted for methods development and theNational Assessment Workshop columns contributed to the development of data aggregation methods and/or analyzed and reviewednational-level assessments of the resulting data.

Survey FormRegional

AssessmentMethods

DevelopmentNational

Assessment

North Atlantic

Arnold Banner U.S. Fish and Wildlife Service √Seth Barker Maine Dept. of Marine Resources √Joceline Boucher Maine Maritime Academy √ √Laurice Churchill Maine Dept. of Marine Resources √Philip Colarusso U.S. Environmenal Protection Agency √Canthy Coniaris University of New HampshireMichael Connor Massachusetts Water Resources Auth. √Jerome Cura Menzie-Cura & Associates Inc. √ √Lee Doggett Maine Dept. of Environmental Protection √ √William Ellis Maine Maritime Academy √Bernie Gardner University of Massachusetts √ √Hap Garritt Woods Hole Oceanographic Institute √Chris Garside Bigelow Laboratory for Ocean Sciences √ √Diane Gould Massachusetts Bay Program √ √Chris Heinig Intertide Corporation √Charles Hopkinson, Jr. Woods Hole Oceanographic Institute √John Hurst Maine Dept. of Marine Resources √Kenneth Keay Massachusetts Water Resources Auth. √Maureen Keller Bigelow Laboratory for Ocean Sciences √ √Jack Kelly U.S. Environmenal Protection Agency √ √ √Peter Larsen Bigelow Laboratory for Ocean Sciences √ √ √Theodore Loder University of New Hampshire √ √ √ √Caroline Martorano University of New HampshireLawrence Mayer University of Maine √Bernard McAlice Darling Marine Center √Mike Mickelson Massachusetts Water Resources Auth. √ √Paul Mitnik Maine Dept. of Env. Protection √ √Byard Mosher University of New Hampshire √Carter Newell Great Eastern Mussel Farm √Judith Pederson MIT Sea Grant √David Phinney Bigelow Laboratory for Ocean Sciences √Frederick Short University of New Hampshire √John Sowles Maine Dept. of Env. Protection √ √David Taylor Massachusetts Water Resources Auth. √ √David Townsend Bigelow Laboratory for Ocean Sciences √Robert Vadas University of Maine √

Middle AtlanticJosephine Aller State University of New York at Stony Brook √Charles App U.S. Environmenal Protection Agency √Sima Bagheri New Jersey Institute of Technology √Robert Biggs Roy F. Weston Inc. √Donald Boesch University of Maryland - Horn Point √ √ √Henry Bokuniewicz State University of New York at Stony Brook √Walter Boynton University of Maryland √ √ √Denise Breitburg Academy of Natural Sciences √Thomas Brosnan National Oceanic and Atmospheric Administration √ √ √Claire Buchanon Interstate Commission on the Potomac River Basin √ √Nick Carter Maryland Dept. of Natural Resources √James Casey Maryland Dept. of Natural Resources √Carl Cerco Army Corps of Engineers √Jonathon Cole Institute of Ecosystem Studies √Robert Connel New Jersey Dept. of Env. Protection √ √Sherri Cooper Duke University √David Correll Smithsonian Environmental Res. Cent. √ √Elizabeth Cosper Cosper Environmental Services, Inc. √ √ √Joseph Costa Buzzards Bay Project √ √Christopher D'Elia State University of New York at Albany √ √Christopher DeAcutis Rhode Island Dept. of Env. Mgmt. √Robert Diaz Virginia Institute of Marine Science √ √Diana Domotor Maryland Dept. of the Environment √Bill Eisele New Jersey Dept. of Env. Protection √ √Deborah Tan Everitt Maryland Dept. of the Environment √ √Thomas Fisher University of Maryland - Horn Point √Anne Giblin Marine Biological Laboratory √Howard Golub Interstate Sanitation Commission √Sandy Groppenbucher New Jersey Dept. of Env. Protetion √ √

Appendix C: Participants



68

Survey FormRegional

AssessmentMethods

DevelopmentNational

Assessment

Middle Atlantic (continued)Marilyn Harlin University of Rhode Island √Donald Heinle CH2M Hill √ √Frederick Hoffman Virginia Water Control Board √ √Norbert Jaworski U.S. Environmental Protection Agency √Tom Jones Salisbury State University √Stephen Jordan Maryland Dept. of Natural Resources √Renee Khan Maryland Dept. of Natural Resources √Grace Klein-MacPhee University of Rhode Island √Al Korndoerhfer New Jersey Dept. of Env. Protection √ √Robert Magnien Maryland Dept. of Natural Resources √ √ √Thomas Malone University of Maryland - Horn Point √ √ √ √James Maughan CH2M HILL √Bruce Michael Maryland Dept. of the Environment √ √Doreen Monteleone New York St. Dept. of Economic Development √Jon Morrison U.S. Geological Survey √James Mummam New Jersey Dept. of Env. Protection √ √Robert Nuzzi Suffolk County Dept. of Health Services √ √Jay O' Reilly NOAA, National Marine Fisheries Service √Paul Olsen New Jersey Dept. of Env. Protection √ √Christine Olsen Connecticut Dept. of Env. Protection √Robert Orth College of William and Mary √Candace Oviatt University of Rhode Island √John Paul U.S. Environmental Protection Agency √ √Jonathan Pennock University of Alabama/Dauphin Island Sea Lab √ √ √ √Ernest Pizzuto Connecticut. Dept. of Environmental Protection √ √Kent Price University of Delaware √Ananda Ranasinghe Versar Inc. √Louis Sage Bigelow Laboratory for Ocean Sciences √ √James Sanders Benedict Estuarine Research Lab √Sybil Seitzinger Rutgers University √Valerie Shaffer Virginia Institute of Marine Science √Frederick Short University of New Hampshire √ √David Simpson Connecticut Dept. of Env. Protection √Carl Sindermann Oxford Laboratory √Theodore Smayda University of Rhode Island √Paul Stacey Connecticut Dept. of Env. Protection √ √R. Lawrence Swanson State University of New York at Stony Brook √Robert Thomann Manhattan College √James Thomas NOAA, National Marine Fisheries Service √Elaine Trench U.S. Geological Survey √Jefferson Turner University of Massachusetts-Dartmouth √Steve Weisberg Versar Inc. √ √Richard Wetzel College of William and Mary √ √Robert Whitlatch University of Connecticut √Gary Wikfors NOAA, NMFS/N.E. Fisheries Science Center √Charles Yarish University of Connecticut √

South AtlanticMerryl Alber University of Georgia √ √Jim Alberts University of Georgia √ √Clark Alexander Skidaway Institute of Oceanography √Richard Alleman South Florida Water Management Dist. √Dennis Allen University of South Carolina √Richard Barber Duke University Marine Laboratory √Diane Barile Marine Res. Council of East Florida √Vincent Bellis East Carolina University √Jackson Blanton Skidaway Institute of Oceanography √Elizabeth Blood J. W. Jones Ecological Research Center √ √Bob Brody St. Johns River Water Mgmt. Dist. √ √Deborah Bronk University of Georgia √Ramesh Buch Dade County Env. Resources Mgmt. √JoAnn Burkholder North Carolina State University √Larry Cahoon Univ. of North Carolina at Wilmington √ √David Chestnut South Carolina Dept. of Health & Env. Control √ √ √Daniel Childers Nat. Marine Fisheries Service/NOAA √Robert Christian East Carolina University √John Cooper East Carolina University √Terry Davis Florida Dept. of Environmental Reg. √Betsy Deuerling City of Jacksonville √Phillip Dunstan College of Charleston √Bob Frease Marine Resources Council of East Fl. √Greg Graves Florida Dept. of Environmental Reg. √Guy Hadley Florida Dept. of Environmental Reg. √Jess Hawkins III North Carolina Div. of Marine Fisheries √Jim Henry Georgia State University √John Higman St. Johns Water Management District √Robert Hodson University of Georgia √ √Fred Holland South Carolina Dept. of Wildlife and Marine Res. √ √ √



69

Survey FormRegional

AssessmentMethods

DevelopmentNational

Assessment

South Atlantic (continued)Jeff Hyland NOAA, National Ocean Service √William Kirby-Smith Duke University √David Knott South Carolina Wildlife & Marine Res. √Alan Lewitus University of South Carolina, Baruch Institute √Wayne Magley Florida Dept. of Environmental Reg. √ √Michael Mallin Univ. of North Carolina - Wilmington √ √ √Susan Markley Dade County Environmental Resources Mgmt. √Hank McKellar University of South Carolina √ √ √Mary Ann Moran University of Georgia √James Nelson Skidaway Institute of Oceanography √Jimmie Overton North Carolina Division of Env. Mgmt. √Hans Paerl University of North Carolina √James Pinckney University of North Carolina - Chapel Hill √Lawrence Pomeroy University of Georgia √Joe Rudek North Carolina Environmental Defense Fund √Russell Sherer South Carolina Dept. of Health and Env. Cntrl. √Donald Stanley East Carolina University √ √ √Stuart Stevens Georgia Dept. of Natural Resources √Steve Tedder North Carolina Div. of Environmental Management √Patricia Tester NOAA, National Marine Fisheries Service √Bob Van Dolah South Carolina Dept. of Wildlife and Marine Res. √ √ √ √Peter Verity Skidaway Institute of Oceanography √ √ √Robert Virnstein St. Johns River Water Mgmt. Dist. √Randy Walker Skidaway Institute of Oceanography √Cecelia Weaver Dade County Env. Resources Mgmt. √A. Quinton White Jacksonville University √Richard Wiegert University of Georgia √Herbert Windom Skidaway Inst. of Oceanography √John Windsor Jr. Florida Institute of Technology √ √

Gulf of MexicoNeil Armingeon Lake Pontchartrain Foundation √Don Axelrad Florida Dept. of Environmental Protection √Bruce Baird U.S. Army Corp of Engineers √Ronnie Best National Biological Survey √Tom Bianchi Tulane University √ √Jan Boydstun Louisiana Dept. of Env. Quality √Joe Boyer Florida International University √Jim Bowman Texas Natural Resources Cons. Comm. √David Brock Texas Water Development Board √ √Fred Bryan Louisiana State University √David Burke Gulf Coast Research Laboratory √Dave Buzon Texas Parks and Wildlife Department √Tom Cardinale Hillsborough County Env. Prot. Comm. √Sneed Collard University of West Florida √Emelise Cormier Louisiana Dept. of Env. Quality √Michael Dagg Louisiana Universities Marine Consortium √John Day Louisiana State University √Charly Demas U.S. Geological Survey √Richard DeMay Barataria/Terrebonne National Estuary Program √Dennis Demcheck U.S.Geological Survey √Hudson Deyoe Texas A&M University √Robert Dickey Gulf Coast Research Laboratory √Juli Dixson University of Southern Mississippi √Kelly Dixon Mote Marine Laboratory √Peter Doering South Florida Water Mgmt. Dist. √ √Quay Dortch Louisiana Universities Marine Consortium √ √Tom Doyle National Biological Survey √Ken Dunton University of Texas √H. Lee Edmiston Apalachicola Natl. Est. Research Reserve √ √Ernest Estevez Mote Marine Laboratory √ √ √Janice Fellers Suwannee River Water Mgmt. District √Nichole Fisher Texas A&M University √David Flemer U.S. Environmental Protection Agency √ √ √ √James Fourqurean Florida International University √Gary Gaston University of Mississippi √ √Cynthia Gorham-Test U.S. Environmental Protection Agency √Holly Greening Tampa Bay Estuary Program √ √ √George Guillen Texas Water Commission √Joe Hand Florida Dept. of Environmental Protection √Albert Hindrichs Louisiana Dept. of Env. Quality √Dan Haurnet South Florida Water Mgmt. Dist. √Richard Iverson Florida State University √ √



70

Survey FormRegional

AssessmentMethods

DevelopmentNational

Assessment

Gulf of Mexico (continued)J. O. Roger Johansson City of Tampa Bay Study Group √Lori Johnson National Biological Survey √Clifford Kenwood Lake Pontchartrain Foundation √Larry Land U.S. Geological Survey √Brian LaPointe Harbor Branch Oceanographgic Inst. √ √Graham Lewis North West Florida Water Mgmt. District √Skip Livingston Florida State University √Steven Lohrenz University of Southern Mississippi √Rodney Mach U.S. Army Corp of Engineers √Robert Mattson Suwannee River Water Mgmt. Dist. √ √Jerry McLelland Gulf Coast Research Laboratory √Ben McPherson U.S. Geological Survey √Russell Miget Texas A&M University √Cynthia Moncrieff Gulf Coast Research Laboratory √Paul Montagna University of Texas at Austin √ √Ralph Montgomery Environmental Quality Lab √Gerold Morrison S.W. Florida Water Mgmt. District √ √Harriet Perry Gulf Coast Research Laboratory √Michael Perry Southwest Florida Water Mgmt. District √Michael Poirrier University of New Orleans √ √Gary Powell Texas Water Development Board √ √Warren Pulich Texas Parks and Wildlife Department √Nancy Rabalais Louisiana Universities Marine Cons. √ √Chet Rakocinski Gulf Coast Research Laboratory √Donald Ray Florida Dept. of Environmental Reg. √Donald Redalje University of Southern Mississippi √ √Bill Rizzo National Biological Survey √Patrick Roques Texas Natural Resources Cons. Comm. √Dugan Sabins Louisiana Dept. of Env. Quality √ √William Schroeder University of Alabama √ √James Seagle Florida Dept. of Natural Resources √ √Frank Shipley Galveston Bay Natl. Estuary Program √Thomas Smith III Rookery Bay Natl. Est. Research Reserve √Kerry St. Pe' LA Dept. of Environmental Quality √Dean Stockwell University of Texas at Austin √ √J. Kevin Summers U.S. Environmental Protection Agency √ √ √Carmelo Tomas U.S. Environmental Protection Agency √David Tomasko S.W. Florida Water Management District √ √ √R. Eugene Turner Louisiana State University √ √Steven Twidwell TNRCC/Water Plan. & Assmnts. Div. √Robert Twilley University of Southwestern Louisiana √ √ √Gabriel Vargo University of South Florida √ √Richard Volk Corpus Christi Bay National Estuary Program √Michael Waldon University of Southwestern Louisiana √Albert Walton Jr. Florida Dept. of Environmental Reg. √William Wardle Texas A&M University at Galveston √Jeff Waters Lake Ponchartrain Basin Foundation √James Webb Jr. Texas A&M University at Galveston √Jay Zieman University of Virginia √

Paci f icJim Arthur Bureau of Reclamation √Shirley Birosik Los Angeles Water Quality Control Bd. √ √Milton Boyd Humboldt State University √Karleen Boyle University of California - Los Angeles √Donald Brown California St. University at Long Beach √ √Randall Brown California Dept. of Water Resources √Barbara Ann Butler Oregon Institute of Marine Biology √Jane Caffrey Elkhorn Slough Nat. Est. Research Reserve √John Chapman Hatfield Marine Science Center √James Cloern U.S. Geological Survey √Brian Cole U.S. Geological Survey √ √Eugene Collias Northwest Consultant Oceanographers Inc. √Barry Collins California Dept. of Fish and Game √Andrea Copping Washington Sea Grant √Frank Cox Washington Dept. of Health √Clayton Creech Hatfield Marine Science Center √Scott Dawson Santa Ana Regional Water Quality Control Board √Andrew DeVogelare Elkhorn Slough Natl. Est. Research Reserve √Robert Emmett NOAA, National Marine Fisheries Service √Peggy Fong University of California - Los Angeles √ √



71

Survey FormRegional

AssessmentMethods

DevelopmentNational

Assessment

Pacific (continued)Jon Graves Columbia R. Estuary Study Task Force √Michael Graybill South Slough Nat. Est. Research Reserve √John Hannum North Coast Regional Water Quality Control Board √ √Jan Hodder Oregon Institute of Marine Biology √James Hollibaugh San Francisco State University √Carol Janzen University of Delaware √John Johnson Oregon Dept. of Fish and Wildlife √ √Deborah Johnston California Dept. of Fish and Game √ √Michael Josselyn San Francisco State √Christopher Kinner Irvine Ranch Water District √Eric Klein Orange Co. Public Facilities & Resources Dept. √Katie Kropp Morro Bay National Estuary Program √Gregg Langlois California Dept. of Health Services √Peggy Lehman California Dept. of Water Resources √Lisa Levin Scripps Institution of Oceanography √Michael Martin California Dept. of Fish and Game √Larry Marxer Oregon Dept. of Environmental Quality √Gregory McMurray Oregon Dept. of Environmental Quality √ √ √Peter Michael San Diego Water Quality Control Board √ VBruce Moore Orange Co. Public Facilities & Resources Dept. √Chad Nelsen Oregon Dept. of Land Cons. & Dev. √Avis Newell Oregon Dept. of Environmental Quality √Jan Newton Washington State Dept. of Ecology √ √ √ √Frederic Nichols U.S. Geological Survey √James Nybakken Moss Landing Marine Laboratory √Don Oswalt Oregon Dept. of Land Cons. & Dev. √Bill Paznokas California Dept. of Fish and Game √Greig Peters San Diego Water Quality Control Board √Bill Peterson Hatfield Marine Science Center √Chris Prescott Puget Sound Water Quality Authority √Harlan Proctor California Dept. of Water Resources √Don Reish California State University √Jack Rensel University of Washington √Curtis Roegner Oregon Institute of Marine Biology √Greg Ruiz Smithsonian Env. Research Center √Steve Rumrill South Slough Nat. Est. Research Reserve √Mary Beth Saffo University of California at Santa Cruz √Kathleen Sayce Shoalwater Botanical √Larry Schemel U.S. Geological Survey √Lynda Shapiro Oregon Institute of Marine Biology √Randy Shuman Metropolitan King County √ √Mark Silberstien Elkhorn Slough Nat. Est. Research Reserve √Lawrence Small Oregon State University √David Specht U.S. Environmental Protection Agency √Pete Striplin Striplin Environmental Assoc. √Barbara Sullivan Oregon State University √Kathy Taylor Columbia R. Estuary Study Taskforce √Ronald Thom Battelle/Marine Sciences Laboratory √ √ √Bruce Thompson San Francisco Estuary Institute √Ken Thompson Irvine Ranch Water District √Tim Unterwegner Oregon Dept. of Fish and Wildlife √William Winchester North Coast Reg. Water Quality Control Board √Karen Worcester Cent. Coast Reg. Water Quality Control Board √ √Jack Word Battelle Ocean Sciences √Joy Zedler University of Wisconsin √ √

NationalRichard Alexander U.S. Geological Survey √Darrell Brown U.S. Environmental Protection Agency √ √Andrew Robertson National Oceanic and Atmospheric Administration √ √Dick Smith U.S. Geological Survey √Richard Valigura National Oceanic and Atmospheric Administration √ √Terry Whitledge University of Alaska Fairbanks √ √ √ √


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