Estimated Annual

Economic Impacts from

Harmful Algal Blooms (HABs)

in the United States

by

Donald M. Anderson

Porter Hoagland

Woods Hole Oceanographic Institution

Woods Hole, MA 02543

Yoshi Kaoru

Nanzan University

Nagoya, Japan

Alan W. White

Massachusetts Maritime Academy

Buzzards Bay, MA 02532

September 2000

Technical Report

Funding was provided by the National Oceanic and Atmospheric

Administration under Grants No. NA46RG0470 and NA90AA-D-SG480,

the National Science Foundation under Grant No. OCE-9321244, and

the Johnson Endowment of the Marine Policy Center.

Approved for public release; distribution unlimited.

DANGER

Area Closed

Shellfish (oysters, clams, mussels, and other

bivalve molluscs) in the area described below

contain paralytic toxins and are not safe

for use as food.

Woods Hole

WHOI-2000-11
Economic Impact of HABs in the U.S.

2

ACKNOWLEDGEMENTS

We extend special thanks to the following people for their assistance in providing information for

this report: D. Baden (University of Miami); D. Blythe (University of Miami); J. Burkholder

(North Carolina State University); R. Conn (City of Sarasota, Florida); L. Fleming (University of

Miami); W. Foster (Department of Marine Resources, State of Maine); R. Haddock (Guam

Department of Public Health); Y. Hokama (University of Hawaii); R. Horner (University of

Washington); J. Hurst (Department of Marine Resources, State of Maine); C. Lobban

(University of Guam); K. Lynch (North Carolina Department of Environment, Health and

Natural Resources); V. Paul (University of Guam); R. RaLonde (University of Alaska); W.

Rothenbach (City of Sarasota, Florida); E. Todd (Department of Health and Welfare, Canada); T.

Tosteson (University of Puerto Rico); K. White (Department of Fisheries and Oceans, Canada);

and R. Weisman (Florida Poison Information Center).

We also thank the following people for information which they provided during the initial stages

of this project: C. Allison (AK); S. Barker (ME); R. Barrett (AK); B. Barss (OR); T. Beardsley

(AK); R. Becker (LA); T. Bettinger (AK); E. Buskey (TX); D. Cannon (OR); K. Canty (MA); P.

Chapman (WA); R. Collins (CA); E. Cosper (NY); E. Cox (TX); R. D'Amico (NY); C.

Dequillseldt (NY); B. Dewey (WA); P. DiPietro (MA); W. Donaldson (AK); B. Eisley (NJ); J.

Finger (CA); A. Freudenthal (NY); J. Garrett (FL); B. Halgren (NJ); R. Hanowell (WA); D. Heil

(FL); Y. Hokama (HI); R. Horner (WA); J. Hunt (FL); J. Hurst (ME); T. Johnson (CA); J.

Johnson (OR); S. Kennedy (FL); G. Langlois (CA); R. Lewis (ME); R. Madiack (NJ); J.

Mahoney (NJ); H. Marshall (VA); M. McCallum (WA); M. McNair (AK); J. Nelson (NH); C.

Newell (ME); R. Nuzzi (NY); P. Olsen (NJ); M. Ostasz (AK); J. Paeth (OR); Pierce Associates

(MA); R. Pierce (FL); H. Radtke (OR); P. Raiche (NH); T. Reisingor (TX); J. Rensel (WA); B.

Roberts (FL); L. Robinson (TX); M. Ross (CA); P. Rubec (TX); Shore Appraisals (MA); D.

Simons (WA); T. Smith (WA); K. Spiller (TX); G. Stater (OR); K.Steidinger (FL); M. Street

(NC); C. Strong (NY); W. Tatum (AL); P. Tester (NC); R. Usher (MA); J. Volk (CT); C. Weise

(AK); T. Whitledge (TX); D. Whittaker (MA); S. Wilk (NJ); and G. Woods (MA). 

We thank Ms. Ellen Gately for typographical assistance with this manuscript, and Ms. Judy

Kleindinst and Ms. Kristin Gribble for their editorial efforts. This research was supported in

part by NOAA National Sea Grant College Program Office, Department of Commerce, under

Grants No. NA46RG0470 and NA90AA-D-SG480, Woods Hole Oceanographic Institution Sea

Grant Projects No. R/B-150-PT and R/S-24, by NSF Grant OCE-9321244, and by the Johnson

Endowment of the WHOI Marine Policy Center.
Economic Impact of HABs in the U.S.

3

EXECUTIVE SUMMARY

Blooms of toxic or harmful microalgae, commonly called "red tides," represent a significant and

expanding threat to human health and fisheries resources throughout the United States and the

world. These phenomena take many forms, ranging from massive accumulations of cells that

discolor the water to dilute, inconspicuous, but highly toxic populations. Ecological, aesthetic,

and public health impacts include: mass mortalities of wild and farmed fish and shellfish; human

intoxication and death from the consumption of contaminated shellfish or fish; alterations of

marine food webs through adverse effects on larvae and other life history stages of commercial

fish species; the noxious smell and appearance of algae accumulated in nearshore waters or

deposited on beaches; and mass mortalities of marine mammals, seabirds, and other animals.

Many harmful algal blooms (HABs) have significant economic impacts. Shellfish closures, wild

or farmed fish mortalities, and scared consumers who avoid seafood are well-recognized impacts

of major HABs. While adverse health effects and lost sales of fish and shellfish products are

direct costs, constrained development or investment decisions in coastal aquaculture due to the

threat from outbreaks of toxic algae are examples of poorly understood or poorly quantified

indirect or hidden costs. Lost marine recreational opportunities also are a significant cost of

harmful algal bloom incidents.

HABs have increased steadily in both species complexity and geographical extent over the last

several decades. In turn, the range of harmful effects and the magnitude of economic costs have

also widened. This report provides the first comprehensive estimate of the economic impacts of

HABs in the United States, focusing on both direct and indirect costs.

We estimate the economic impacts of HABs for events where such impacts were measurable

with a fair degree of confidence during the six-year interval of 1987-92 (Table ES.1). Due to

reporting limitations, the selected events are a subset of all outbreaks that occurred during the

1987-92 study period, and thus our aggregate economic impact underestimates the true impacts.

“Economic impact” is defined broadly to mean either lost gross revenues in the relevant product

or factor markets, expenditures for environmental monitoring and management, or other costs that

would not have been incurred in the absence of HABs. In general, this measure is consistent with

published estimates made for other natural catastrophes, such as hurricanes or earthquakes.

Economic multipliers, often used to approximate the full ramifications of costs or losses as they

are transferred through a local economy, are not used here. The calculation of economic

multipliers in the absence of detailed data on market structure and interactions can be misleading,

as multipliers can be sensitive to local market structure characteristics and to the quality of data

that describe interactions among market sectors. Developing a description of local and regional

markets for specific HAB events was beyond the scope of this project. 
 Estimated Annual Economic Impacts from Harmful Algal Blooms (HABs) in the United States

(Estimate is of 1987-1992 period, reported in 2000 dollars)

% of 

Low High Average Total

$ 18,493,825 $ 24,912,544 $ 22,202,597 45%

hery $ 13,400,691 $ 25,265,896 $ 18,407,948 37%

ism $ - $ 29,304,357 $ 6,630,415 13%

nagement $ 2,029,955 $ 2,124,307 $ 2,088,885 4%

$ 33,924,471 81,607,104 $ 49,329,845 $ 100%

zed Impacts

%) $308,981,162 $743,270,485 $449,291,987
Economic Impact of HABs in the U.S.

5

Economic impacts are grouped into four basic categories: (1) public health impacts; (2)

commercial fishery impacts; (3) recreation and tourism impacts; and (4) monitoring and

management costs. Unless otherwise indicated, all estimates are reported in 2000 U.S. dollars.

Public Health Impacts

Human sickness and death from eating tainted seafood results in lost wages and work days.

Costs of medical treatment and investigation also are an important part of the economic impact

caused by such events. Cases of sickness and death from shellfish toxins are probably the most

clearly documented among the different types of HAB impacts, since these cases are recorded by

public health agencies in individual states as well as at the federal level.

For the 1987-92 period, the average public health impact due to shellfish poisoning from HABs

was approximately $1 million per year (caused by paralytic, neurotoxic and amnesic shellfish

poisoning, or PSP, NSP, and ASP respectively). This total is low because of highly effective

state monitoring programs that detect toxic shellfish and keep contaminated products off the

market. Another problem caused by toxic algae is the fish poisoning syndrome called ciguatera,

caused by dinoflagellate toxins that move through the tropical food chain to the larger fish that

then poison human consumers. Ciguatera affects predominantly the residents of, and visitors to,

Florida, Hawaii, Puerto Rico, the U.S. Virgin Islands, Guam, and the Marshall Islands. Over the

study interval, the economic impact of ciguatera poisoning varied from $18 million to more than

$24 million per year, averaging $21 million. These estimates are low since ciguatera poisoning has

occurred outside the tropical areas listed above due to exports of fish to other jurisdictions.

Further, some seafood companies purchase insurance to cover potential ciguatera-caused

liabilities, and there are court costs associated with ciguatera-related litigation – neither of which

we were able to quantify for the study interval. 

The total public health impacts from HABs ranged from a low of $18 million to a high of $25

million, averaging $22 million over the six-year interval. These figures represent approximately

45% of the total economic impacts from all causes. 

Commercial Fishery Impacts

Commercial fishery impacts from HABs include wild harvest and aquaculture losses of fish and

shellfish resources due to NSP, PSP, ASP, ciguatera, and brown tides. Annual impacts vary from

$13 to $25 million with average annual impacts of $18 million. These figures clearly are

underestimates because they do not include losses from PSP closures in several states where it

was not possible to document the acreage closed or the value of the resource that was not

harvested. The estimation of commercial fishery impacts is complicated further by the transfer

of shellfishing effort from closed areas to areas that remained open and by fishermen switching to

other fishing activities. In addition, the estimates do not include the value of wild fish kills or of

lost opportunities for harvesting some untapped shellfish resources. Measuring the economic

impacts of wild fish kills is problematic because many involve so-called “trash” fish that, by
Economic Impact of HABs in the U.S.

6

definition, have no market value. Also, the ultimate causes of fish kills often are unclear. For

example, fish kills caused by the dinoflagellate Pfiesteria undoubtedly occurred in North Carolina

during the six-year study interval, but state officials could not indicate which events were caused

by Pfiesteria and which were due to other causes, such as low dissolved oxygen.

Another issue is that some currently untapped fishery “resources” have values that could be

realized in the absence of HAB events, but such estimates are not included here. Examples

include some shellfish resources of coastal Alaska, which are permanently quarantined due to

persistent PSP toxicity and the logistics of sampling distant or remote resources. However, in

order for such “lost opportunities” to be counted legitimately as economic impacts in this study,

these fisheries must be demonstrated to be commercially viable. A plausible alternative reason

for non-exploitation is that they are not profitable fisheries because there is insufficient demand

or because harvesting is uneconomical. The annual economic impact estimates presented here

include losses from these untapped resources only in certain special cases (e.g., surf clams in

Alaska and on Georges Bank).

Recreation and Tourism Impacts

In 1991, a federal study estimated that expenditures by recreational fishermen for travel, food,

lodging and equipment were 67 percent greater than expenditures for commercial fish landings.

Although many experts argue that the impacts of HABs on recreation and tourism are important

and potentially large, there are few available data describing the size of the impacts. Clearly, the

economic impacts of HABs on recreational and tourism activities deserve substantially more

attention than they have been given to date. In Florida, for example, recurrent red tides have been

estimated to cause over $20 million in tourism-related losses every year. These impacts, as well

as similar losses in Texas and other areas, are not well documented and thus are reduced to much

lower levels in this study. The total annual estimates for recreation and tourism are, once again,

underestimates. Efforts to measure recreation and tourism impacts must be undertaken at the

local level because local environmental and socioeconomic conditions are critical determinants of

changes in recreational benefits.

Estimates of economic impacts on recreation and tourism during the 1987-92 period range from

zero to $29 million. The annual average is $7 million.

Monitoring and Management Costs

It is often the case that water monitoring tasks, including shellfish testing for PSP, NSP, and

ASP, are spread across different divisions of state government, making it difficult to collect data

on costs. Further, monitoring activities for both HABs and other water quality testing, such as

shellfish sanitation, often are conducted by the same personnel. As a result, it is difficult to

factor out those costs related specifically to HAB monitoring and management. Given this

qualification, annual average monitoring and management costs for HABs are estimated at $2

million, distributed among twelve states: Alaska, California, Connecticut, Florida, Maine,
Economic Impact of HABs in the U.S.

7

Massachusetts, New Hampshire, North Carolina, New Jersey, New York, Oregon, and

Washington. These costs include the routine operation of shellfish toxin monitoring programs,

plankton monitoring, and other management activities.

Conclusions

Table ES-1 presents the annual aggregate economic impacts (in millions of 2000 dollars) of HABs

in the United States during the 1987-92 period. The total costs average $49 million per year,

ranging from $34 million to $82 million. Over the last several decades, the cumulative impacts

thus approach $1 billion. Public health impacts are the largest component, representing more

than 45 percent of total average impacts. Commercial fisheries impacts are the next largest

component, representing 37 percent of the total. Recreation/tourism impacts account for 13

percent of the total, and monitoring/management impacts represent the remaining 4 percent.

Further, it is important to note that expenditures made to improve monitoring and management

likely resulted in decreases in impacts in the other categories.

These estimates are highly conservative and reflect the difficulties in compiling and assessing the

impacts of phenomena for which economic studies are rare. The totals in Table ES-1 do not

include the effects of economic multipliers, which would increase the estimates several-fold.

They also do not include the value of untapped or unexploited resources, such as some of the

extensive shellfish populations along Alaska’s 30,000-mile coastline, presently closed to

harvesting due to PSP toxicity. Likewise, the effects of delayed harvesting, as with temporary

beach closures due to PSP, could not be estimated with any precision and thus are not included. 

We note also that outbreaks of certain blooms may cause severe economic impacts that equal or

exceed the annual averages for the selected study interval. For example, a 1976 New Jersey red

tide caused losses estimated at more than $1 billion in 2000 dollars. Similarly, the 1997 Pfiesteria

outbreak in the Chesapeake Bay is estimated to have cost the seafood industry $46 million.

These single events exceed the annual average of HAB impacts for the entire nation. 

The difficulties encountered in our efforts to generate a national estimate of HAB economic

impacts underscore the need to modify the manner in which HABs are reported. At present,

information on HAB events is fragmentary and inconsistent with respect to the level of detail

provided. The duration, affected acreage or shoreline length, average toxicity levels, and values of

affected coastal resources should be documented for each bloom in order to describe the overall

economic significance of the incident. In addition, local and state governments should place

much higher emphasis on quantification of economic impacts. Until local governments become

capable of supplying site-specific impact information for each bloom incident, truly

comprehensive and detailed national level aggregation of such impacts cannot be realized.

Furthermore, the causes of economic impacts and the degree of their uncertainty should be

included in any reports of economic impacts.
Economic Impact of HABs in the U.S.

8

Overall, the economic impacts from HABs are diverse and large within the United States. Even

with the highly conservative treatment given the impacts in this study, the annual costs are

significant. Perhaps more importantly, many are recurrent, and show signs of increasing as the

number of toxic and harmful algal species grows and as our reliance on the coastal zone for

aquaculture, commerce and recreation expands. Prudent investment in research and monitoring

can do much to reverse this trend and to reduce the annual impacts. 
Economic Impact of HABs in the U.S.

9

TABLE OF CONTENTS

1 INTRODUCTION................................................................................................................13

2 METHODS...........................................................................................................................16

2.1 Definition of Economic Impacts................................................................................16

2.2 Economic Impacts are not an Ideal Measure of Social Costs...............................17

2.3 Ex Ante vs. Ex Post Impacts......................................................................................19

2.4 Nonmalleable Factors.................................................................................................19

2.5 Other Types of Impacts..............................................................................................19

2.6 Distribution of Impacts...............................................................................................20

2.7 Usefulness of the Economic Impact Measure ........................................................20

2.8 Study Interval ..............................................................................................................20

2.9 Data ...............................................................................................................................21

3 PUBLIC HEALTH IMPACTS.............................................................................................22

3.1 PSP, NSP, and ASP Illnesses.....................................................................................22

3.1.1 Illness Costs...........................................................................................................22

3.1.2 Unreported Illnesses ..............................................................................................25

3.2 Ciguatera.......................................................................................................................26

4 COMMERCIAL FISHERY IMPACTS ..............................................................................28

4.1 Wild Harvest and Aquaculture Losses...................................................................28

4.1.1 Brown Tide Impacts on Bay Scallop Harvests in New York................................28

4.1.2 ASP Impacts on Razor Clam Harvests in Washington and Oregon.......................31

4.1.3 Alaskan Shellfish Resources...................................................................................32

4.1.4 Ciguatera Impacts on Sales of Recreational Fish in Hawaii ...................................32

4.1.5 West Coast Harvesting Delays ..............................................................................32

4.1.6 Inconclusive Impacts on Shellfish Harvests in Maine and Massachusetts............33

4.1.7 Impacts from the Application of Health Standards...............................................34

4.1.8 Impacts of Wild Fish Kills.....................................................................................34

4.1.9 Inconclusive Evidence of Seagrass Dieoffs in Florida ............................................36

4.2 Untapped Fisheries.....................................................................................................36

4.2.1 Alaska’s Untapped Shellfish Resources ................................................................37

4.2.2 Georges Bank Surf Clam Fishery...........................................................................42

4.2.3 Georges Bank Roe-On Scallop Fishery..................................................................42

4.3 Major HAB Events in Other Years..........................................................................43

5 RECREATION AND TOURISM IMPACTS.....................................................................44

5.1 The 1987 North Carolina Red Tide Event ................................................................45

5.2 The 1991-92 Washington and Oregon ASP Event.................................................45
Economic Impact of HABs in the U.S.

10

5.3 Recreational Impacts - Large but Uncertain...........................................................46

5.4 Laguna Madre Brown Tide........................................................................................47

5.5 Property Value and Recreational Impacts of Macroalgae.....................................47

6 MONITORING AND MANAGEMENT COSTS .............................................................49

7 CONCLUSIONS AND FUTURE RESEARCH NEEDS...................................................51

7.1 Annual Aggregate Economic Impacts.....................................................................51

7.2 Reasons Why Our Estimates are Conservative......................................................51

7.3 Information Needs.......................................................................................................54

7.4 Overview.......................................................................................................................55

8 REFERENCES......................................................................................................................56

APPENDIX A ........................................................................................................................61

APPENDIX B ........................................................................................................................89
Economic Impact of HABs in the U.S.

11

LIST OF FIGURES Page

Figure 2.1. Economic costs of a HAB event in a commercial fishery 17

Figure 2.2. Economic costs of a HAB event in a recreational fishery 18
Economic Impact of HABs in the U.S.

12

LIST OF TABLES Page

Table 3.1. Illness due to natural seafood toxins in the United States 23

Table 3.2. Shellfish poisoning impacts from harmful algal blooms 24

Table 3.3. Public health impacts of ciguatera 27

Table 4.1. Commercial fishery impacts 29

Table 4.2. New York commercial bay scallop landings (1980-84) 31

Table 4.3. Landed values in shellfish in Maine (1988 and 1992) 33

Table 4.4. Massachusetts state PSP testing results 35

Table 4.5. Status of Alaskan molluscan shellfish resources 38

Table 4.6. Estimated “net” gross revenues arising from opening the Alaskan 41

and Georges Bank surf clam fisheries

Table 5.1. Recreation and tourism impacts 44

Table 5.2. Washington state recreational shellfishing trips for razor clams 46

Table 6.1. Annual average monitoring and management costs 50

Table 7.1. Estimated annual economic impacts from harmful algal blooms 52

in the United States
Economic Impact of HABs in the U.S.

13

1 INTRODUCTION

Ocean waters are home to thousands of species of microscopic algae which together comprise the

base of the marine food web. Most of these species are harmless, and in fact are critical to the

ocean’s ecology and to the production of biomass at all levels of the marine food web. There are,

however, a few dozen algal species which are associated with adverse impacts of many different

types. The term “harmful algal bloom” or HAB is now used to describe the destructive and often

visible "blooms" of these algae that kill fish, make shellfish poisonous, and cause numerous other

problems in marine coastal waters. The one feature uniting these diverse phenomena is that they

cause harm. In the past, the term “red tide” was used to describe many of these phenomena, but

the term is potentially misleading and does not adequately describe the many different types of

harmful outbreaks. Some algal species produce potent toxins which accumulate in shellfish that

feed on those algae, resulting in poisoning syndromes in human consumers called paralytic,

diarrhetic, amnesic, and neurotoxic shellfish poisoning (PSP, DSP, ASP, and NSP respectively).

A related phenomenon called ciguatera fish poisoning (CFP) occurs when toxic algae living on

coral reef seaweeds are consumed by herbivorous fish, which pass the toxins on to larger

predators which then deliver the neurotoxins to human consumers. All of these toxins can also

alter marine ecosystem structure and function as they are transferred through the food web,

affecting fecundity and survival at multiple levels in ways that are still largely unquantified.

Some toxic blooms kill wild and farmed fish populations. Others are associated with irritating

and toxic aerosols, due to the transport of toxins in sea spray. Even non-toxic algal species can

cause problems through biomass effects - shading of submerged vegetation, disruption of food

web dynamics and structure, and oxygen depletion as the blooms decay. Traditionally, the term

HAB has referred to microscopic algae, but its interpretation has now been broadened to include

blooms of macroscopic algae (seaweeds) which displace indigenous species, destroy habitat,

cause oxygen depletion, and even alter biogeochemical cycles. The causes and effects of

macroalgal blooms are similar in many ways to those associated with harmful microscopic

phytoplankton species. 

During the past several decades, HAB events have occurred in more locations than ever before

throughout the United States and the world (Anderson 1989; Smayda 1990; Hallegraeff 1993).

The number of algal species involved in such events has increased, there are more known toxins,

more fisheries resources are affected, and the economic impacts of HAB outbreaks are larger as

well. Whether or not this global increase in HABs is taking place because of enhanced nutrient

and pollutant loadings from anthropogenic sources has been a topic of debate within the scientific

community (e.g., Anderson 1989; Smayda 1990). Whatever the reasons, virtually all coastal

regions of the United States are now subject to an unprecedented variety and frequency of HAB

events. The United States is not alone in this respect, as nations throughout the world are

increasingly faced with a bewildering and disturbing array of toxic or harmful species and

impacts.
Economic Impact of HABs in the U.S.

14

In the United States, the most significant economic and public health problems related to harmful

algae during the 1987-92 interval that is the focus of this study were: 

• Paralytic shellfish poisoning (PSP), which occurs in all coastal New England states as

well as New York and along much of the west coast from Alaska to California. This

problem has also extended to offshore areas in the Northeast, notably Georges Bank.

• Neurotoxic shellfish poisoning (NSP), and fish and marine mammal mortalities in the

Gulf of Mexico and, more recently, extending northward to the coast of the Carolinas. 

• Mortalities of farmed salmonids in the Pacific Northwest.

• Recurrent brown tides, causing mortalities of mussel populations, massive recruitment

failure of scallops, and reduction of eelgrass beds around Long Island.

• Ciguatera fish poisoning (CFP), a malady associated with dinoflagellate toxins

accumulated in tropical fish flesh, occurring in virtually all sub-tropical to tropical

United States waters, including Florida, Hawaii, Guam, United States Virgin Islands,

Puerto Rico, and many Pacific Territories. 

• Amnesic shellfish poisoning (ASP), a sometimes fatal illness so named because one of

its most severe symptoms is the permanent loss of short-term memory. The ASP

toxin, domoic acid, has been detected in shellfish from both the West and East Coasts

of the United States, and toxic Pseudo-nitzschia multiseries cells have been isolated

from Gulf of Mexico water.

• Diarrhetic shellfish poisoning (DSP) which some consider the most serious and

globally widespread phytoplankton-related seafood illness. The first confirmed

incidence of DSP in North America occurred in 1990 and 1992 in Canada. DSPproducing species of phytoplankton such as Dinophysis acuminata and Prorocentrum

lima occur throughout all temperate coastal waters of the United States, though no

outbreaks of DSP have yet been confirmed.

• “Pfiesteria-like" dinoflagellates, affecting human health and fisheries in estuaries of the

southeastern United States, and in particular the Neuse-Pamlico estuaries. Although

Pfiesteria had been discovered by 1992, economic impacts of fish kills caused by this

organism are not included in this study because no data could be obtained on the fish

kills conclusively linked to Pfiesteria over the 1987-92 interval, or of the value of the

dead fish. In the laboratory, human exposure to aerosols from toxic Pfiesteria cultures

has been linked to short- and long-term neurotoxic symptoms. Fishermen and others

working in or exposed to estuarine waters have complained of similar problems,
Economic Impact of HABs in the U.S.

15

exemplified in the worst cases as a loss of neurocognitive ability. There are no

estimates of the economic impacts of these human health effects in this report, again

because of a lack of data.

• Blooms of macroalgae (seaweeds), in response to nutrient enrichment associated with

coastal eutrophication. Opportunistic macroalgal species outcompete, overgrow, and

replace seagrass and coral reef ecosystems. Once established, the macroalgal blooms

may remain in an environment for decades until nutrient supplies decrease. Negative

effects include reduced light availability to seagrasses and reef systems, leading to

lower productivity, habitat loss from hypoxia/anoxia, and eventual die-off of sensitive

species. 

In this report, we provide a national estimate of the economic impacts of HABs from events for

which such impacts were measurable with a fair degree of confidence during the interval 1987-92.

(Unless otherwise indicated, all estimates are reported in 2000 U.S. dollars.) Due to inadequate

reporting, the events included here are only a subset of the HAB outbreaks that occurred

during the six year study period. For this reason and others (discussed below) we believe

that our aggregate economic impact estimates significantly underestimate the true

impacts. We acknowledge that “economic impact” is not an ideal measure of economic loss, but

we employ the concept in this study because it is the predominant form in which damages are

reported by coastal managers and by scientists in the published literature. We group economic

impacts into four basic categories: 1) public health impacts; 2) commercial fishery impacts; 3)

recreation and tourism impacts; and 4) monitoring and management costs. This is the first effort

to estimate economic costs of HABs at the national level, so it is perhaps not surprising that in

the course of this analysis, we encountered many unknowns and uncertainties with respect to

quantifying impacts. These problems are discussed below.
Economic Impact of HABs in the U.S.

16

2 METHODS

The following economic impact analysis is based mainly on a survey of experts from individual

coastal states and the literature. Formal letters requesting economic impact information were

mailed in August 1992 and February 1994 to individuals in certain heavily impacted states who

were either knowledgeable about HAB impacts or who were likely to know others who could be

contacted for more specific details. In total, more than 170 people were contacted by letter and

by telephone to elicit economic impact information and to uncover details about individual HAB

events. After a preliminary evaluation and synthesis of these data, topics requiring further data

or analysis were identified. These were addressed through a new series of telephone calls and

correspondence in 1997-99. We have summarized these data in the body of the report.

2.1 Definition of Economic Impacts 

We define “economic impacts” broadly to mean either lost gross revenues in the relevant product

or factor markets, expenditures for environmental monitoring and management, or other costs that

would not have been incurred in the absence of HABs. In general, this measure is consistent with

published estimates made for other kinds of natural catastrophes, such as hurricanes or

earthquakes (e.g. Pielke and Landsea 1997; Pielke and Pielke 1997). As such, the estimates

reported here represent a preliminary, but admittedly rough, approximation of the economic

costs to the United States from the occurrence of HABs. Readers should keep the limitations of

economic impact analysis in mind, realizing that it was developed as a purely descriptive

technique. Its original purpose was to describe the economic structure of a region, to help

understand economic interactions and linkages among sectors. In particular, it is not a form of

benefit-cost analysis, and it should not be used to justify normative decisions (Propst and

Gavrilis 1987).

Another consideration is that we do not apply “multipliers” in this report to capture the full

ramifications of economic impacts. Multipliers can be sensitive to local market structure

characteristics and to the quality of data that describe interactions among market sectors (Archer

1995; Propst and Gavrilis 1987). Developing a description of local and regional markets for

specific HAB events was beyond the scope of this project. We have identified some studies of

HAB impacts in which multipliers have been estimated and used, such as Maine's economic

impact calculation for shellfishing closure of September 1980, and we recognize that it is possible

to calculate multipliers for this kind of application (Loomis 1993). However, we believe that the

calculation of economic multipliers in the absence of detailed data on market structure and

interactions can be potentially misleading, creating a perception of exaggerated economic costs of

HAB events (e.g. Hunter 1989). Furthermore, the occasional misuse of economic impact analysis

to make normative decisions to justify investments, for example, is made all the worse when

impacts are multiplied.
Economic Impact of HABs in the U.S.

17

2.2 Economic Impacts are not an Ideal Measure of Social Costs

Economic impacts as defined here are not an ideal measure of the costs of HABs to society.

Under ideal circumstances, we would like to obtain a measure of lost consumer and producer

surpluses in the relevant markets due, say, to shifts in demand or supply curves. We

demonstrate this point in Figure 2.1, which depicts supply and demand in a commercial fishery

during one season1

. Assume that we are considering the costs associated with the closure of a

fishery due to a HAB event. In a typical case, this can be represented by a shift of the supply

curve, which itself is the horizontal sum of marginal cost schedules for individual firms, from S0

to S1. The effect is a reduction in the supply of fish to the market, from F0 to F1, and an increase

in the price of fish, from P0 to P1. Prior to the closure, the net benefits flowing from the fishery

are the sum of producers’ surplus (E+F+G) and consumers’ surplus (A+B+C+D). After the

closure, producers’ surplus now becomes area B+E and consumers’ surplus is reduced to area A.

The net economic loss associated with the closure is therefore C+D+F+G. Compare this

theoretically correct, but often more difficult to obtain, measure with lost gross revenues from the

closure (G+I). It should be clear that the latter is not a very close approximation of “true”

economic losses. In particular, although G is a true economic loss, I represents resources that can

be productively invested or utilized elsewhere in the economy.

$

P1

S1

A

B C D

G

E

F

H

I

P0

S0

F1 F0 Fish

supply

demand

Figure 2.1. Economic costs of a HAB event in a commercial fishery.

 

1

We examine the case of the lower section of the traditional backward bending supply curve. This example is relevant to the

case of a fishery managed to maximize economic yield.
Economic Impact of HABs in the U.S.

18

$

DF1 DF0

M0

M1

P

B

A

C

D

E

Days

Fished

Figure 2.2 Economic costs of a HAB event in a recreational fishery.

The case of a recreational fishery is represented in Figure 2.2. In the present study, we have

estimated economic impacts as the product of lost days fished, e.g., due to a fishery closure,

times average daily recreational expenditures. (Note that some recreational fisheries may have a

commercial component, complicating the analysis.) However, this measure does not represent a

true economic cost of a HAB event because, when expenditures are not made, individual

recreational fishermen incur no costs. Nevertheless, there may be consumer surplus losses,

which represent true economic costs. Assume that there exists a recreational “market” demand

curve (M) along which fishing success (i.e., catch rate) is assumed to be constant (Anderson

1986). Prior to a HAB event, gross benefits are equal to area A+B+C+D+E and expenditures are

equal to area C+D+E. Net benefits are therefore equal to area A+B. Now assume that an algal

bloom results in the closure of some fishing areas, causing reduced catch rates in areas that remain

open, say, due to increased fishing pressure in the latter.2 Because fishing success declines, area

closures will result in the contraction of recreational market demand for each level of aggregate

days fished: for example, M0 shifts down to M1. At the current level of fishing expenditures of

 

2

 Other scenarios are certainly possible. For example, a bloom event may result in the closure of an entire recreational

fishery. Closures could be temporal, instead of spatial, limiting the total days fished. Analyses of other scenarios should

be straightforward.
Economic Impact of HABs in the U.S.

19

P, a new equilibrium of DF1 aggregate days fished is established. Following the logic described

above, net benefits at the new level of days fished are equal to area B. The loss in consumer

surplus from the closure is equal to area A. Note that there is no explicit market for days fished.

The demand for days fished is a “non-market” demand. Estimation of this demand, and therefore

losses to a recreational fishery from a HAB event, requires the application of specialized

economic methods.

2.3 Ex Ante vs. Ex Post Impacts

The point in time at which impacts are measured also must be considered. When a commercial or

recreational fishery is closed ex ante, then the appropriate measure of economic effects is the sum

of lost consumer and producer surpluses, as described in the previous paragraphs. However, if

commercial fish have been harvested already and the product subsequently prevented from

reaching the market because toxicity exceeds safe levels, then it is appropriate to add harvest

costs (area I in Figure 2.1) to the measure of economic losses. Harvest costs are included because

they are a measure of resources that have been utilized to no productive effect. Another example

is the occurrence of a HAB that affects an operating coastal aquaculture facility that must

subsequently incur additional depuration costs or dispose of tainted product. In both examples,

there may be additional costs, such as higher tipping fees, associated with the disposal of the

tainted seafood. 

2.4 Nonmalleable Factors

Another source of economic costs relates to the ease with which capital or labor can be

transferred to other productive activities. In the economic models described above, we assume

that fishing vessels, processing plants, fishermen, etc. will immediately and costlessly switch to

their next best alternative activity. In other words, capital and labor are assumed perfectly

“malleable.” However, when examining specific cases, we may find that this assumption is not

valid. Good examples include empty hotel rooms or slowed restaurant trade resulting from

reduced coastal tourism during a HAB event. As another example, it may be costly for fishermen

to re-rig their boats or steam to another fishing ground when a HAB closure has been declared.

Often, economic impact studies will assume that capital and labor is completely nonmalleable. In

this report, where feasible, we point out any malleability assumptions in the studies that we cite. 

2.5 Other Types of Impacts

We have collected data on other types of impacts. The economic impacts that we measure in the

form of hospitalization costs or monitoring and management costs are true economic costs.

These activities represent the allocation of scarce medical and management resources that

otherwise would be devoted to other health problems or public goals. Interestingly, these

activities help to mitigate the larger “potential” costs of HAB events. For example, monitoring
Economic Impact of HABs in the U.S.

20

might prevent the consumption of toxic seafood, and hospitalization might reduce mortality from

seafood consumption. As a result, there may be net benefits from undertaking these activities.

(The existence of net benefits will depend upon a comparison of the total costs and total benefits

of these activities.) Our economic impact analysis does not account for the benefits of these

types of mitigating activities. 

2.6 Distribution of Impacts

Note that some firms in the relevant market actually may benefit from a HAB event. For

example, if a fishing location is closed because of a HAB event, a firm fishing for the same species

in a location that remains open may actually see an increase in price for its product. Although

there is a clear net loss at the market level, local net gains or net losses may occur, and the

distribution of gains and losses may not be uniform across all localities. Unless demand is

perfectly elastic with respect to price, consumers will unambiguously lose because of price

increases when supply is reduced as a consequence of a HAB event. Some will even be unwilling

to purchase the fish or shellfish at the new higher price.

2.7 Usefulness of the Economic Impact Measure

Even though our measure of economic impacts is not theoretically correct, it can still be useful.

First, this measure is very easy to collate and calculate. To our knowledge, there are few studies

that have examined the true economic costs of HAB events, but many have estimated economic

impacts. Second, this approach can give an idea of the scale of the problem. If economic impacts

are found to be large in any particular instance, it indicates that we need to take a closer look at

the true economic losses. Third, the geographic location of economic impacts can give an

estimate of where local losses occur, and the type of impact can help us identify the relevant

market. When combined with an understanding of the relevant product or factor market, we may

be able to predict where local net gains might occur. Thus, economic impact analysis can give a

feel for the distributional effects of a HAB event.

2.8 Study Interval

We examine a “window” of impacts resulting from events during the six-year period from 1987 to

1992 to develop an estimate of “annual” economic impacts. There is still a great deal of

uncertainty about the frequency and spatial distribution of HAB occurrences. Because of this

uncertainty, the choice of a shorter period could result in either under- or over-estimates of

economic impacts, depending upon when and where HAB events occurred. The six-year period

was the longest period for which we could collect a consistent set of data within the constraints

of the project. Although our choices about the timing and duration of the study period are

somewhat arbitrary, we believe that it gives us a reasonable interval within which to develop

credible estimates of the annual economic impacts of HAB events at the national level.
Economic Impact of HABs in the U.S.

21

2.9 Data

Although we made an effort to gather economic impact data as comprehensively as possible, both

the type and amount of available data were limited. Most coastal states have neither

conducted economic analyses of HABs nor collected data that can be used to generate

reliable quantitative economic impact estimates. In many cases, the complex physical and

ecological characteristics of the coastal environment make it difficult to determine whether an

algal bloom is the immediate and relevant cause of certain coastal phenomena such as fish kills,

oxygen depletion, or seagrass dieoffs. Moreover, local experts often differ substantially in their

opinions about the magnitude of economic impacts from HABs.

In Appendix A, we summarize HAB events reported informally by individual coastal state

experts to a “national office” of the ICES Center for the Exchange of Information on Exceptional

Plankton Blooms, located at the Woods Hole Oceanographic Institution. Although the data are

rudimentary in nature, these are the only national compilations of bloom data. In Appendix B,

we present the names and affiliations of the individuals with whom we corresponded.
Economic Impact of HABs in the U.S.

22

3 PUBLIC HEALTH IMPACTS

Human sickness and death from eating tainted seafood results in lost wages and work days.

Costs of medical treatment and investigation also are an important part of the economic impact

caused by such events. Individuals who are sick may also experience pain and suffering. In

theory, these feelings could be quantified in economic terms, but we make no attempt to do so

here. Cases of sickness and death from shellfish toxins are probably the most clearly documented

among the different types of HAB impacts. Because of the high level of public interest in

seafood safety, these cases are recorded by public health agencies in individual states as well as at

the federal level.

3.1 PSP, NSP, and ASP Illnesses

During 1978-87, paralytic shellfish poisoning (PSP) was a minor cause of seafood-borne illness in

the United States, according to data on illness cases reported to the Center for Disease Control

(CDC) in Atlanta (Table 3.1). Only two deaths due to PSP were reported during this period.

Nishitani and Chew (1988) present data on reported PSP cases during 1979-87 in the four Pacific

Coast states: Alaska, Washington, Oregon, and California. These data show that in the more

recent years there were far fewer PSP cases than in the earlier years, especially in California. A

separate report from the U.S. Food and Drug Administration identifies shellfish poisoning cases

for the 1973-92 period (Rippey 1994). The reported number of PSP sickness cases varies widely

across these sources. For example, the CDC reports no PSP cases in 1987, but Nishitani and

Chew (1988) report seven PSP cases in Alaska in that year. Because reports to CDC are

voluntary, we believe that the CDC database underestimates the number of PSP sickness cases in

any year.

For the 1987-92 period, we show in Table 3.2 our estimate of the public health impacts resulting

from PSP, NSP, and ASP. Impacts ranged from $11,098 to $4.84 million, with an average cost of

$1.02 million. The illness and death cases presented in Table 3.2 were compiled from the

information in Appendix A and the tables in Nishitani and Chew (1988) and Rippey (1994).

A few cases of respiratory complaints and eye irritation are reported in Appendix A.

Aerosolized toxins, such as those from Gymnodinium breve in Florida, may well have caused

some of these cases. However, these complaints are not included in Table 3.2 because of the

difficulty in quantifying the number of cases as well as their impacts.

3.1.1 Illness Costs

We adopt the estimates used by Todd (1995) for PSP illnesses (C$1500 [1993 Canadian dollars]

per reported illness and C$1180 [1993 Canadian dollars] per unreported illness) to estimate the

costs of foodborne disease due to PSP, NSP, and ASP in the United States. Unreported illnesses
Economic Impact of HABs in the U.S.

23

Table 3.1: Illness Due to Natural Seafood Toxins in the United States

Reported to the Center for Disease Control

Ciguatera PSP

Year Outbreaks Cases Outbreaks Cases

1978 19 56 4 10

1979 21 97 1 3

1980 15 52 5 116

1981 30 219 1 -

1982 8 37 - 5

1983 13 43 - -

1984 18 78 - -

1985 26 104 2 3

1986 18 70 - -

1987 11 35 - -

Total 179 791 13 137

NOTE: An outbreak is an incident involving two or more sick individuals, and a case is a single

ill person. Source: F. E. Ahmed (ed.), 1991. Seafood Safety, p. 89.
Economic Impact of HABs in the U.S.

24

Table 3.2: Shellfish Poisoning Impacts from Harmful Algal Blooms

Year State Type Reported Unreporteda

Impactsb

(000s)

Florida PSP 3 27

North Carolina NSP 47 423

1987

Alaska PSP 7 63

$633

1988 Washington PSP 5 45

Alaska PSP 3 27

$89

1989 New York PSP 2 18

California PSP 2 18

$44

1990 Massachusetts PSP 8 72

Alaskac PSP 2 18

$4,836

California PSP 11 99

Washington/Oregon ASP 28 252

1991

Alaska PSP 5 45

$488

1992 Alaska PSP 1 9 $11

Avg. 21 185 $1,016

a

Reported illnesses are estimated to be 10 percent of all illnesses due to HAB events (Todd, pers. comm.,

1997).

b

Economic impacts are estimated at $1,374 per reported illness, $1,081 per unreported illness,and $4.73

million per death (2000 dollars). (Please see the text for references.) Values in the table are reported in

2000 dollars.

c

Includes one mortality in Alaska.

Sources: Appendix A, Nishitani and Chew (1988), and Rippey (1994).
Economic Impact of HABs in the U.S.

25

do not, by definition, incur medical and transportation costs. Illness costs include lost

productivity due to sick days, costs of medical treatment and transportation, and costs

associated with investigations for the cause of the sickness.3 The figures we use are downward

revisions of earlier estimates published by Todd (1989a, 1989b). Because cost information is not

available specifically for NSP or ASP illnesses, we apply the cost estimates for PSP cases to

these illnesses.

 During the study period, one person died from PSP in Alaska in 1989. Our estimate of the

economic impact per death is based upon labor market studies of the implicit value of life

(Viscusi 1993). Such studies have been used to develop estimates of both the value of life and

the costs of nonfatal illnesses from empirical data that relate wage premiums to job risks. These

studies suggest that there is a range of the value of life from $3 to $7 million, and we use an

estimate of $4 million for the one life lost in Alaska (1993 dollars).

3.1.2 Unreported Illnesses

We know that a substantial number of illnesses caused by HABs remain unreported. However,

no reliable method has been proposed for extrapolating from the reported cases to estimate the

true number of illnesses. Todd (1989a) proposed multiplying the number of reported cases by a

factor of ten to estimate the total. Until better information on unreported illnesses is available, we

believe that the most conservative way to report our findings is to provide cost estimates based

upon actual, reported poisoning episodes, using Todd’s multiplier, without additional arbitrary

adjustments.

Our estimate of public health costs of unreported illnesses is much lower than the annual PSP

costs of $2.31 million (2000 U.S. dollars) estimated for the United States by Todd (1989a), who

employed much larger estimates of costs per illness (C$6000 in 1985 Canadian dollars) during a

different period (1978-82). Todd’s calculation also accounts for the likelihood that unreported

cases are very likely to be less serious than reported cases, implying that there may be lower

associated medical treatment and investigation costs. Following Todd’s lead, we multiplied the

number of reported cases during 1987-92 by 10, and weighted reported illnesses by the higher

cost per illness. Our annual average estimate of the public health impacts due to shellfish

poisoning was $1.02 million (2000 U.S. dollars), a value that is substantially less than Todd’s

(1989a) estimate.

 

3

 Labor market studies have also been used to estimate the implicit value of nonfatal injuries. These estimates fall in the

range of $25 to $50 thousand (Viscusi 1993). Other methods for valuing morbidity effects, such as survey techniques,

result in estimates that range from $700 to $3500, which are more consistent with Todd’s estimates of illness costs (e.g.,

Viscusi et al. 1987). Note, however, that survey methods are very sensitive to perceptions of risks. 
Economic Impact of HABs in the U.S.

26

3.2 Ciguatera

Another problem caused by toxic algae is the syndrome called ciguatera fish poisoning (CFP),

which is linked to dinoflagellate toxins that move through the tropical food chain to the higher

predators. Although ciguatera technically is not a “bloom” phenomenon, we investigate it

because it originates with toxic microalgae and has significant economic and public health costs

(e.g. Ragelis 1984). In Table 3.3, we report the number of human sicknesses due to ciguatera

poisoning in Florida (Weisman, pers. comm., 1997), Hawaii (Hokama, pers. comm., 1994),

Puerto Rico (Tosteson, pers. comm., 1997), the U.S. Virgin Islands (Tosteson, pers. comm.,

1997), Guam (Haddock, pers. comm., 1997), and the Marshall Islands (Ruff 1989). We develop

our own estimates of sicknesses in Palau, Micronesia, the Northern Mariana Islands, and

American Samoa based on the incidence of ciguatera illnesses in the Marshall Islands.4

 To be

consistent across all regions, we adopt Todd’s (1995) estimate of the illness costs (1993

Canadian dollars) due to ciguatera of C$1100 (US$1,007 [2000 dollars]) per reported case and

C$750 (US$687 [2000 dollars]) per unreported case. This may result in an overestimate of

ciguatera costs in Puerto Rico, as Tosteson (pers. comm., 1997) thinks that the costs per

reported case are lower in Puerto Rico—about US$532 per reported case (2000 dollars). 

Experts differ on the ratio of reported to unreported illnesses in each jurisdiction. We use the

following ratios: 1:4 for Florida (Weisman, pers.comm., 1997); 1:10 for the Marshall Islands,

Palau, Micronesia, the Northern Mariana Islands, and American Samoa (our own estimate); and

1:100 for Hawaii, Guam, Puerto Rico, and the U.S. Virgin Islands (Tosteson, pers. comm., 1997

and our own estimates). The economic impact varies from $17.72 million to $24.28 million per

year, averaging $21.19 million on an annual basis. It is clear that the economic impacts due to

ciguatera poisoning account for most of the public health impacts from toxic algae. Nevertheless,

we may not be estimating the true scale of the problem. Ragelis (1984), for example, notes that

ciguatera poisoning often occurs outside of tropical areas due to exports of tropical fish to other

jurisdictions. Further, some seafood companies now purchase insurance to cover potential

ciguatera-caused liabilities, and there are also court costs associated with ciguatera-related

litigation, which has become quite common. We have no estimates of these costs, so again, our

estimates are conservative. 

 

4

 We include the Marshall Islands, Palau, and Micronesia in our U.S. estimate because all three nations have a “compact of

free association” with the United States and all three are heavily dependent upon the United States for foreign aid. The

Northern Mariana Islands is a Commonwealth in political union with the United States, much like Puerto Rico. American

Samoa is a territory of the United States much like the U.S. Virgin Islands.
Table 3.3: Public Health Impacts of Ciguatera

(estimates of reported and unreported illnesses for each jurisdiction)

PuertoRicob,c

Virgin

Islandsb,c

Guamb Marshall

Islandsd

American

Samoae

Northern

Mariana

Islandse

Palaue Micronesiae Totals Estimated

impacts

(2000

$U.S.

millions)f

0 200 19775 6 593 5 495 264 2376 30 270 32 290 7 66 51 456 935 33982 26.52

23 200 19775 6 593 15 1485 264 2376 30 270 32 290 7 66 51 456 932 33685 26.29

29 200 19775 6 593 4 396 264 2376 30 270 32 290 7 66 51 456 915 32002 25.01

72 162 16025 5 481 11 1089 264 2376 30 270 32 290 7 66 51 456 840 24575 19.36

9 162 16025 5 481 6 594 264 2376 30 270 32 290 7 66 51 456 868 27347 21.47

52 162 16025 5 481 2 198 264 2376 30 270 32 290 7 66 51 456 851 25664 20.18

sman (pers.comm. 1997) estimates that only one in four ciguatera cases in Florida are reported.

assume only one in 100 ciguatera cases are reported in these jurisdictions, based upon Tosteson’s (pers. comm. 1997) estimate for

rto Rico.

eson (pers.comm. 1997) estimates reported ciguatera cases are 0.6 percent of the population during 1987-89 and 0.5 percent of the

ulation during 1990-92.

f (1989) estimates that only one in ten ciguatera cases are reported in the Marshall Islands.

estimate that one in ten ciguatera cases are reported in these jurisdictions, based upon Ruff’s (1989) estimate for the Marshall Islands.

use also the average incidence of ciguatera in the Marshall Islands as a hazard rate for these jurisdictions.

d (pers.comm. 1997) estimates ciguatera illness costs of Can$1100 (1993 dollars) per reported case and Can$750 (1993 dollars) per

ported case.
Economic Impact of HABs in the U.S.

28

4 COMMERCIAL FISHERY IMPACTS

In Table 4.1, we present HAB events for which commercial fishery impact information was

obtained. Most of these events are described in further detail in Appendix A. Annual impacts

vary from $13.82 to $25.88 million. Average annual impacts are $18.95 million (2000 dollars).

 

4.1 Wild Harvest and Aquaculture Losses

We estimate total commercial harvest losses during a November 1987 to February 1988 G. breve

bloom in North Carolina (Tester et al., 1991) to be $8.27 million. We estimate total impacts of

$17.64 million arising from the deaths of farmed Atlantic salmon killed by phytoplankton blooms

in Washington in 1987, 1989, and 1990 by multiplying the market price of salmon by the weight

of lost fish. Two commercial shellfishing interests, Taylor United and the Coast Oyster

Company, estimate a combined $1.22 million loss incurred during a shellfish recall resulting from

the detection of PSP toxins in Washington State shellfish. Several other HAB events are further

clarified in the following sections.

4.1.1 Brown Tide Impacts on Bay Scallop Harvests in New York

In 1985, a brown tide bloom first appeared in the Peconic Estuary, Long Island and has

reappeared since on a regular basis. The most significant economic impact was the eradication of

the Peconic’s nationally significant bay scallop stocks. The Suffolk County Department of

Health Services estimates that the 1982 value of commercial landings of bay scallops from the

Peconic Estuary was $12.55 million (SCDHS 1992). (A multiplier may have been used to arrive

at this estimate.) However, Tettelbach and Wenczel (1993), citing a report by Rose (1987),

estimate the value of commercial bay scallop landings from New York waters for the years

preceding the 1985 brown tide incident at a much lower level, averaging $2.60 million (2000

dollars) (Table 4.2).5

 In the only study we are aware of that looks at lost surpluses (instead of

lost sales) from a HAB event, Kahn and Rockel (1988) estimate annual total consumers’ and

producers’ surplus losses from the elimination of bay scallop populations in Long Island waters

at a very similar level of $3.27 million (2000 dollars).

 

5

 Landing values are measured at the average U.S. bay scallop price of $4.91/lb. (1984 dollars). The average price was

$4.46/lb. in 1985. Estimates of lost output have been converted into 2000 dollars in the table.
Economic Impact of HABs in the U.S.

29

Table 4.1: Commercial Fishery Impacts*

(2000 $U.S. millions)

Year Incident Type State

Estimated

Impacts

Total

Annual

Estimated

Impacts

Harvest losses of clams,

oysters, scallops, and finfish

NSP North Carolina 8.27

Lost sales of recreational fish CFP Hawaii 3.17

Bay scallop mortality BT New York 3.27

Farmed fish kills HAB Washington

(Cypress

Island)

0.75

1987

Bitter crab disease in tanner

crabs

Closure of surf clam fishery

PD

PSP

Alaska

Alaska

0.16

5.72 21.33

Lost sales of recreational fish CFP Hawaii 3.17

Bay scallop mortality BT New York 3.27

1988

Bitter crab disease in tanner

crabs

Closure of surf clam fishery

PD

PSP

Alaska

Alaska

0.16

8.29 14.89

Farmed fish kills HAB Washington

(Cypress

Island)

11.01

Lost sales of recreational fish CFP Hawaii 3.17

Bay scallop mortality BT New York 3.27

Closure of surf clam fishery PSP Massachusetts

(Georges

Bank)

0.13

1989

Lost value of unprocessed

geoducks and bitter crab

disease in tanner crabs

Closure of surf clam fishery

PSP,

PD

PSP

Alaska

Alaska

1.49

6.15 25.27

1990 Farmed fish kills HAB Washington

(Central Puget

Sound)

5.88

Lost sales of recreational fish CFP Hawaii 3.17

Closure of surf clam fishery PSP Massachusetts

(Georges

Bank)

-0.01
Economic Impact of HABs in the U.S.

30

Table 4.1: Commercial Fishery Impacts (Continued)

Year Incident Type State

Estimated

Impacts

Total

Annual

Estimated

Impacts

1990 Bay scallop mortality

Lost value of unprocessed

geoducks and bitter crab

disease in tanner crabs

Closure of surf clam fishery

BT

PSP,

PD

PSP

New York

Alaska

Alaska

3.27

1.49

-0.39 13.40

Lost sales of recreational fish CFP Hawaii 3.17

Bay scallop mortality BT New York 3.27

Closure of surf clam fishery PSP Massachusetts

(Georges

Bank)

0.23

Harvest losses of razor clams ASP Oregon 0.11

1991

Lost value of unprocessed

geoducks and bitter crab

disease in tanner crabs

Closure of surf clam fishery

PSP,

PD

PSP

Alaska

Alaska

1.49

8.04 16.31

Lost sales of recreational fish CFP Hawaii 3.17

Bay scallop mortality BT New York 3.27

Product recall costs for one

firm

PSP Washington 1.22

Closure of surf clam fishery PSP Massachusetts

(Georges

Bank)

0.26

Harvest losses of razor clams ASP Oregon 0.21

1992

Lost value of unprocessed

geoducks; bitter crab disease

in tanner crabs; and PSP

event in Dungeness crab

fishery

Closure of surf clam fishery

PSP,

PD

PSP

Alaska

Alaska

1.99

9.14 19.25

*Not included are unknown impacts from unexploited resources of surf clams and tellin in the

Bering Sea and roe-on-scallop from Georges Bank (see the text for more detail). Key to type of

harmful algae bloom: ASP=amnesiac shellfish poisoning; BT=brown tide; CFP=ciguatera fish

poisoning; HAB=harmful algae bloom (not otherwise identified); NSP=neurotoxic shellfish

poisoning; PD= paralytic dinoflagellate; PSP=paralytic shellfish poisoning.
Economic Impact of HABs in the U.S.

31

Table 4.2: New York Commercial Bay Scallop Landings (1980-84)

Year

Bay Scallop

Landings

(000 lbs)

Landed Value

($4.91/lb)

(1984 $ millions)

Landed Value

(2000 $ millions)

1980 425 2.09 3.43

1981 245 1.20 1.97

1982 500 2.46 4.04

1983 165 0.81 1.33

1984 275 1.35 2.22

Average 322 1.58 2.60

Source: Tettlebach and Wenczel (1993)

Because bay scallop reseeding efforts have been unsuccessful, and actual bay scallop landings

between 1986 and 1991 from New York waters were negligible in comparison with landings

before the brown tide incident (Tettelbach and Wenczel 1993), we assumed the commercial

fishery impact occurred every year during our study interval. We note that although the Kahn

and Rockel study employs the theoretically correct methodology for valuing economic losses, the

measure of lost surpluses is not compatible with the other data on lost sales that we have

collected for this category. In this specific case, however, the measure of lost surpluses is almost

exactly the same size as the measure of lost sales, 6 and we use an estimate of $3.27 million for

economic impacts in this fishery.

Brown tide also may have affected oyster production in the Peconic system. The estimated

commercial landings of oysters in the Peconic Estuary were about $5.84 million in 1982,

plummeting to less than $14,000 per year in 1987 (SCDHS 1992). However, it is unclear, first,

whether these losses were due solely to brown tide and, second, whether they occurred on an

annual basis. They therefore have not been included in our tabulations. 

4.1.2 ASP Impacts on Razor Clam Harvests in Washington and Oregon

Since the autumn of 1991, the occurrence of ASP has adversely affected the primarily recreational

shellfisheries for razor clams in Oregon and Washington. According to the Oregon Department of

Fish and Wildlife, an average of 58,000 lbs. of razor clams (at $3.65/lb.) were harvested

commercially on an annual basis before closures were imposed. This implies that potential

annual harvest losses are $0.21 million for the commercial market (2000 dollars). Because the

 

6

 There is no reason to believe that this will always be the case. The relative sizes of lost surpluses and lost sales will

depend upon the elasticities of demand and supply.
Economic Impact of HABs in the U.S.

32

ASP events occurred during the fall season of 1991, we use 50 percent of this impact estimate in

1991 and the full impact estimate for 1992. In Washington State, the commercial harvest of razor

clams was 23,103 lbs. in 1991.7

4.1.3 Alaskan Shellfish Resources

Ralonde (1998) estimates that the cost of PSP to Alaska in terms of lost value in commercial

fisheries, closures of recreational shellfishing beds, and mouse bioassays is on the order of $10

million per year (1998 dollars). With respect to commercial fisheries impacts, Ralonde estimates

three types of costs: geoduck processing effects, bitter crab disease (BCD) in tanner crabs

(caused by dinoflagellate parasites), and a 1992 PSP event in Dungeness crabs. Ralonde

calculates the 1996 lost value of geoducks due to the fact that they have to be processed to

remove the viscera, where PSP toxin is concentrated. This reduces their value. Annual lost

income in 1996 was $1.32 million (2000 dollars). Because the sales of geoducks in 1996 were

approximately equal to the six-year average, we use the 1996 estimate of lost sales as an annual

estimate for the period 1989-92 (the fishery began in 1989). Ralonde estimates the lost value in

1996 of tanner crabs due to BCD at $163,209 (2000 dollars). We assume that this is the annual

lost value due to BCD during 1987-92. Finally, in 1992, a PSP event resulted in a $500,783 loss

of sales in the Dungeness crab fishery (2000 dollars). 

4.1.4 Ciguatera Impacts on Sales of Recreational Fish in Hawaii

Ciguatera impacts in Hawaii are estimated at $2.75 million per year (1994 dollars) based on the

dollars per lb. of fish unmarketable due to ciguatera (Hokama, pers. comm., 1994). This estimate

represents potential losses of retail sales from catches made mainly in sport fishing. Note that, in

this case, the value of sport fishing recreation per se is not diminished, but the retail sale is lost.

If the act of selling a caught fish is a valued part of the sport fishing experience, then the

nonmarket value of recreational fishing may also be reduced. It is difficult, however, to estimate

the latter impact. 

4.1.5 West Coast Harvesting Delays

In California, Oregon, and Washington, Nishitani and Chew (1988) argue that shellfishing

closures due to PSP have resulted mainly in harvesting delays, and not in significant financial

losses. Our discussions with several New England commercial shellfishing companies suggest

that short-term closures cause few operational problems and that long-term closures cause

 

7 No further commercial harvest information was received. However, we were told that most of the razor clams in

Washington are found at public beaches where commercial harvests are prohibited.
Economic Impact of HABs in the U.S.

33

financial losses only infrequently, e.g., once in every ten years.8 However, the situation may be

quite different in New England because there are many more independent clam diggers who may

be affected by shellfish closures (Shumway et al. 1988). This is a complex area of impact needing

further investigation. Although these other impacts may exist, the only data we have at present

on commercial fishery economic impacts from HABs are due mainly to exceptional events like

those presented in Table 4.1.

4.1.6 Inconclusive Impacts on Shellfish Harvests in Maine and Massachusetts

Because of inconclusive information, Table 4.1 does not present all of the potential commercial

fishery losses caused by HABs during the 1987-92 period. For Maine and Massachusetts, we

tried, unsuccessfully, to infer fishery impacts from a relationship between the frequency of

shellfish closures due to PSP (or numbers of shellfish samples testing positive for PSP) and

annual harvest values. For example, in Maine, 1988 was the year with the greatest number of

HAB closures, and 1992 was the year with the least (Lewis, pers. comm., 1994). Table 4.3

presents the landed values of the four major shellfish species9

 in Maine in those two years.

Lower landed values ($12.80 million) occurred in 1992 than in 1988 ($16.20 million).10 Clearly,

in Maine, shellfish closure frequency is not a good predictor of economic impacts.

Table 4.3: Landed Values of Shellfish in Maine (1988 and 1992)

(millions of dollars)

Shellfish 1988

(Constant $)

1988

(2000$)

1992

(Constant $)

1992

(2000$)

Clams 6.83 9.86 7.86 9.56

Mussels 2.17 3.13 1.02 1.24

Quahogs 1.86 2.68 1.46 1.78

Oysters 0.38 0.55 0.14 0.17

Total 11.24 16.20 10.48 12.80

Source: Lewis, pers. comm. (1994)

 

8

 In Washington State, one shellfish grower stated that a worst-case scenario would involve a 3-week PSP closure, costing about

$27,000 (1994 dollars), which might happen once every 10 years. An annual PSP closure, from 1 July to 1 November, of pink

scallops that are marketed whole costs $58,000 (1994 dollars). However, several other commercial fishermen indicated to us

that there was not much impact from PSP closures.

9 In Maine, sea scallops must be processed at sea, and only the adductor muscles are landed and marketed. Because scallop

adductor muscles do not accumulate PSP toxins, scallops are not affected by HAB closures.

10 Total landings in these years exhibit the same pattern.
Economic Impact of HABs in the U.S.

34

A similar situation applies to Massachusetts. The Massachusetts Division of Marine Fisheries

provided us with data on the state's annual PSP tests (Whittaker, pers. comm., 1994). Table 4.4

presents the number of shellfish samples tested, the ratio of the samples with greater than

80μg/100g of PSP, and the annual commercial shellfish landing values in Massachusetts from less

than 3 miles offshore for the 1987-92 period.11 The years 1987-90 show the highest sample

proportions of PSP contamination. However, a comparison with annual shellfish landing values

fails to reveal a relationship between lower landed values and more frequent detection of PSP

contaminated samples. Likewise, the numbers of contaminated samples alone do not indicate the

severity or duration of HAB events.

Maine and Massachusetts officials record neither acreage closed to shellfishing due to HAB

events nor shoreline miles affected by HAB closures. Records of shellfish closures or openings

are complex, including partial extensions of closures or the reopening of already closed areas.

Further, Maine has 50,000 acres of potential shellfish beds, but 90 percent of the state's total

clam harvest is produced on about 10 percent of its acreage. Therefore, we conclude that it is not

feasible to estimate commercial fishery impacts reliably from closure acreage or shoreline miles

affected by HABs. 

Finally, the co-occurrence of high coliform counts or of shellfish sanitation problems with HABs

makes it difficult to factor out the economic impacts that are due solely to HAB events. For

example, samples collected from certain areas in Massachusetts in 1994 showed high PSP levels,

warranting shellfish closures. However, the same areas had been closed already due to high

coliform bacteria levels.

4.1.7 Impacts from the Application of Health Standards

Maine oyster farmers and shellfish dealers lost $0.72 million in 1988 when their shipments of

oysters tested positive for DSP by The Netherlands (Shumway 1990). However, the results of

further analyses of the same shipments tested negative for DSP. Because the shipments were

presumably uncontaminated, this economic impact was not included in our analyses.

4.1.8 Impacts of Wild Fish Kills

Concerns are sometimes raised in the topical literature about "indirect" commercial fishery

impacts, such as wild fish kills and lost opportunities to harvest untapped shellfish resources.

Wild fish kills were reported in many states (Appendix A), but for numerous reasons, measuring

 

11 The shellfish landing values exclude shrimps, crabs, squid and lobsters that are not usually affected by HABs.

(Appendix E presents annual shellfish and finfish landing values for all coastal states.)
Economic Impact of HABs in the U.S.

35

Table 4.4: Massachusetts State PSP Testing Results

Year Species

# of

Samples

Tested

Ratio of

Samples

with PSP >

80μg

Total

Commercial

Landings

(000s)

Mussel 285 0.000

Surf Clam 49 0.388

1987

Ribbed Mussel 26 0.000

16,710

Mussel 361 0.047

Softshell Clam 105 0.124

Surf Clam 44 0.386

Ribbed Mussel 38 0.000

1988

Quahog 7 0.000

14,834

Mussel 371 0.070

Ribbed Mussel 76 0.000

Surf Clam 69 0.406

1989

Softshell Clam 67 0.164

11,765

Mussel 396 0.043

Softshell Clam 86 0.116

Surf Clam 78 0.513

1990

Ribbed Mussel 58 0.000

12,243

Mussel 348 0.003

Surf Clam 26 0.192

Ribbed Mussel 24 0.000

1991

Softshell Clam 20 0.000

12,008

Mussel 389 0.018

Surf Clam 48 0.083

1992

Ribbed Mussel 24 0.000

14,057

Source: Whittaker, pers. comm. (1994)
Economic Impact of HABs in the U.S.

36

 the economic impacts of such kills is problematic. First, many of these kills involve so-called

“trash” fish, which have no market value by definition. Even local officials who regularly

investigate fish kill events make no attempt to estimate the economic impacts of kills of trash

fish. Second, the ultimate causes of fish kills often are unclear, making it difficult to attribute

them to an algal bloom.12 Fish kills can be the result of oxygen depletion (due to high fish

populations, high temperatures, or HABs), disease, bacteria, nutrients, chemical spills, or some

combination of these or other factors. Potential economic impacts associated with recent fish

kills (primarily menhaden) attributed to the dinoflagellate Pfiesteria are not included in our

estimates because of the uncertainty in attributing fish kills to this organism prior to 1992. In

more recent years, the economic impact from outbreaks of Pfiesteria-like organisms has been

significant. For example, Seiling and Lipton (1998) estimated that lost sales of Maryland seafood

(of all types) due to a fish kill linked to Pfiesteria during the summer of 1997 amounted to $45.70

million (2000 dollars). These lost sales were due entirely to the “halo effect.”

4.1.9 Inconclusive Evidence of Seagrass Dieoffs in Florida 

Gorte (1994) estimates that $16.10 million per year (2000 dollars) is the potential income loss

due to the substantial decline in pink shrimp harvests from Florida Bay, hypothesized to be the

result of a seagrass dieoff due, in turn, to blooms of blue-green algae. Using an economic

multiplier, total impacts were estimated at $36.90 million. However, there is substantial

uncertainty about the real causes of the seagrass dieoff and its linkage to blue-green algae (Gorte

1994; Hunt, pers. comm., 1994). Further, economic recession and foreign competition within the

shrimp industry are other plausible reasons for the industry’s decline. Here again, our loss

estimates do not include these uncertain impacts.

4.2 Untapped Fisheries

Some currently untapped fishery “resources” may have potential values that could be realized in

the absence of HAB events. Examples include the shellfish resources of coastal Alaska (e.g.,

Neve and Reichardt 1984) and surf clams on Georges Bank. However, in order for such “lost

opportunities” to be counted legitimately as economic impacts, these fisheries must be

demonstrated to be commercially viable. A plausible alternative reason for why these resources

are untapped is that they are not now profitable fisheries. These issues are discussed in more

detail below. 

 

12 During 1980-89, NOAA found that 12 out of 22 coastal states reported more than 50 percent of all probable fish kills

(NOAA 1991b). Maine, New Hampshire, Massachusetts, Pennsylvania, Delaware, North Carolina and South Carolina

reported between 76 and 100 percent of probable fish kills. Each fish kill event was attributed to one or more of 20

possible causes (e.g., low dissolved oxygen, temperature, HABs, wastewater, and eutrophication, pesticides, among others).

During the 1980-89 period, the numbers of fish kill events attributed at least in part to HABs were: New York (2), Virginia

(2), Florida (2), and Texas (8). States like New Jersey, North Carolina, and Washington did not identify HAB as a direct

cause for any of their fish kill events. 
Economic Impact of HABs in the U.S.

37

4.2.1 Alaska’s Untapped Shellfish Resources

In Table 4.5, we report on the commercial status of Alaskan molluscan shellfish resources.

Current yields are more than one million pounds per year generating approximately $4.33 million

in gross revenues (2000 dollars). The status of Alaskan shellfish stocks and their commercial

significance are summarized annually by the Alaska Department of Fish and Game,13 and they

have been reviewed by Foster (1997), Schink et al. (1983), and Jewett and Feder (1981). All

commercial shellfish except for the Pinto abalone, chitons, and limpets are threatened by PSP

contamination (Foster 1997). Recently, some species have tested positive for ASP. Yields of

razor clam, weathervane scallop, and geoduck (see below) are processed to remove portions of

the animal that may be toxic. The Pacific oyster, blue mussel, and Pacific littleneck clam are

cultured species for which bioassays are conducted as they are produced. Black katy chitons, fat

gapers, gumboot chitons, and limpets are all subsistence fisheries for which there is no major

commercial market. Historically, significant quantities of butter clams (1946) and cockles (1962)

were produced off the Alaskan coast. More recently, however, only minor harvests have taken

place, and, although small markets for these species exist on the west coast of the United States,

it is not clear that historical levels of production could be commercially viable (Ostasz,

pers.comm., 2000, 1994). A 1977 NMFS survey of the southeast Bering Sea revealed significant

quantities of great Alaskan tellin clams (Lutz and Incze 1979; Nelson et al. 1979), but there is no

known market for tellin in the United States.

The 1977 NMFS survey also revealed potentially exploitable quantities of the Alaskan surf clam

(Spisula polynyma) in the Bering Sea. Hughes and Bourne (1981) estimate an annual maximum

sustainable yield (MSY) of 25,017 metric tons for this resource. The Alaskan discovery came at

a crucial time in the U.S. surf clam market, as the mid-Atlantic surf clam (Spisula solidissima)

resource had just suffered a steep decline due to an oxygen depletion event in the New York

Bight, and the price of surf clams tripled during 1976 and remained high for the next ten years as

the resource recovered. In 1979, Lutz and Incze (1979) valued the annual potential sustainable

yield of surf clams at $28-47 million (2000 dollars). However, only small quantities of Alaskan

surf clams have been harvested since the 1977 stock assessment was conducted. 

The reasons for the lack of a viable Bering Sea surf clam fishery are not completely clear, but

several hypotheses have been put forward. First, some of the surf clam resource has tested

positive for PSP. Neve and Reichardt (1984) argued that persistent PSP was largely responsible

for the non-exploitation of this resource. However, Ostasz (pers.comm., 2000), citing Hughes

and Nelson (1979), notes that only a small proportion (2 out of 185 samples) had detectable

levels of PSP toxin in 1978, and no samples tested positive for toxin in 1977. Because Alaska

 

13Shellfish statistics are updated annually at http://www.cf.adfg.state.ak.us/geninfo/shellfsh/shelhome.htm#species.
Table 4.5: Status of Alaskan molluscan shellfish resources

CIES LOCATION YEAR HARVEST PRICE REVENUE PSP STATUS CITE

lbs $/lb $m Threat

giganteus Southeast 1946 1,763,698 PSP minor 1995-96 harvest Nishitani and Chew

(1988)

m

Southeast 1962 1,302,932 PSP minor 1995 harvest Nishitani and Chew

(1988)

gigas Southeast,

Southcentral

1996-98 874,318 0.41 0.36 PSP cultured (bioassayed) ADF&G (1999)

ula Cook Inlet 1995-99 339,025 0.16 0.05 PSP processed (toxin

removed)

ADF&G (1998);McNair (pers. comm.,2000)

n caurinus Yakutat 1999 280,000 3.00 0.84 PSP processed (toxin

removed)

ADF&G (2000)

n caurinus Kodiak 1996 270,000 6.00 1.62 PSP processed (toxin

removed)

ADF&G (1998)

rupta Southeast 1995-99 193,491 3.38 0.65 PSP processed (toxin

removed)

ADF&G (2000);McNair (pers. comm.,2000)

na

Cape Spencerto Yakutat

50,000 9.12 0.46 Imamura (1994)

staminea Southeast;

KachemakBay

1995-99 45,331 2.69 0.12 PSP cultured (bioassayed) ADF&G (1999);

McNair (pers. comm.,2000)

n caurinus Cook Inlet 1996 30,000 7.00 0.21 PSP processed (toxin

removed)

ADF&G (1998)

is Southeast,

Southcentral

1996-98 4,674 2.23 0.01 PSP cultured (bioassayed) ADF&G (1999)

nyma Bristol Bay 1985 0.54 0.00 PSP minor 1985 harvest Ralonde (1998);

Hughes and Bourne(1981)

unicata Southeast 1985 subsistence fishery Foster (1997)

x Southeast 1985 PSP subsistence fishery Foster (1997)

n stelleri Southeast 1985 subsistence fishery Foster (1997)

Southeast 1985 subsistence fishery Foster (1997)

a Bristol Bay 1985 PSP no fishery Lutz and Incze (1979)
39

has not “classified” the Bering Sea according to NSSP standards, harvesting the resource is

currently infeasible.14

A second plausible reason for the lack of production may be that the fishery is not commercially

viable (Foster 1997). Certainly, production of surf clams at the MSY level is likely to drive price

down in the U.S. surf clam market, thereby decreasing the profitability of the fishery or even

precluding its initiation. Further, the structure of the market may present an entry barrier into

this fishery. With respect to the mid-Atlantic surf clam fishery, Weninger (1998:755) states that:

“[t]he perishable nature of the clams, scheduling of processing activities, and the need to

coordinate with downstream buyers requires tight vertical coordination between fishers and

processors." Without the establishment first of a costly processing infrastructure, and

considering the difficulty of distributing product from a remote location, it may be difficult for a

surf clam fishery to get established in Alaska. Finally, Ostasz (pers.comm., 2000) suggests that

seasonal closures might be imposed on a potential surf clam fishery to protect juvenile spawning

grounds for King crab. It is possible that the timing or area coverage of a closure would increase

the cost of surf clam fishing to levels that might not support a fishery.

Finally, there has been concern expressed over the potential impacts on walrus stocks from the

harvesting of Alaskan surf clams, which are an important food source for walrus (Stoker 1979 as

cited by Foster 1997). This concern might express itself in opposition from environmental

interests should a commercial operation be initiated. The Alaskan Eskimo Walrus Commission

has the responsibility for protecting surf clam resources in walrus habitat (Ostasz, pers. comm.

2000).

Even in the face of uncertain business factors and potential environmental opposition, reports

continue to surface stating that a $50 million Alaskan surf clam resource is precluded by HABs.

We do not have critical information on the cost of producing Alaskan surf clams, but we can

hazard a rough estimate of the economic impacts associated with a hypothetical Bering Sea

fishery. To accomplish this, we make the following assumptions:

• The only obstacle to commercialization of the Alaskan surf clam resource is the potential

presence of shellfish poisoning (PSP or ASP);

• The Alaskan surf clam is a close substitute for the Atlantic surf clam and will compete in the

same market;

• Production of the Alaskan (and Georges Bank) resources at estimated MSY levels is likely to

affect the price of surf clams in the U.S. market (by driving it down);

 

14 Classification might occur if significant commercial interest arose. Foster (1997) notes that the turnaround time on the

mouse bioassay from Alaska’s one shellfish testing lab may be too long for a resource that quickly spoils.
40

• There is no expansion of existing demand such as might occur, for example, through the

opening of an export market;

• An Alaskan surf clam fishery is financially viable and will produce at MSY;

• For the years 1989-1992, an Atlantic surf clam fishery on Georges Bank is financially viable

and produces at the 1988 level of yield;

• Fishermen in the mid-Atlantic fishery will continue to harvest the same amount of Atlantic

surf clams as before. 

If we multiply the current market price times the hypothetical yield of Alaskan and Georges

Bank surf clams to obtain “lost gross revenues” due to PSP, the value of yields of Alaskan,

Georges Bank, and mid-Atlantic surf clams will all be too high. To arrive at a more realistic

price, we adapt and modify the specification embodied in a demand model for the mid-Atlantic

surf clam fishery which was developed by Armitage (1985).15 We fit the model using monthly

data from 1991-98 to estimate updated parameters that describe how the price of surf clams

varies with the quantity supplied to the market (and other related variables).16

The results of this analysis are presented in Table 4.6. Using annual yield and annual average

price data for 1987-92, we estimate the price of surf clams [column (D)] that would have

resulted from the production of mid-Atlantic surf clams at historical levels, Alaskan surf clams at

the MSY level, and Georges Bank surf clams at the 1988 level (the latter only for the years of

closure: 1989-92). We then use this price to calculate the potential “lost” gross revenues for

both Alaskan [column (F)] and Georges Bank [column (G)] surf clams due to HABs closures.

Note that the “gain” to the Alaskan and Georges Bank surf clam fisheries actually results in a

decline in gross revenues in the mid-Atlantic fishery (compare column [E] with column [C]). In

order to calculate the “net” contribution to gross revenues in the national surf clam market that

results from expanded supply, we apportion17 the reduced gross revenues in the mid-Atlantic

 

15 Armitage’s (1985) model is developed with quarterly data from 1976 to 1980. Note that one of our assumptions assumes

that industry structure remains unaffected. As price declines, we might expect some marginal fishermen to exit the mid-Atlantic

fleet. With a change in fleet size, it is possible that less product will be harvested in the mid-Atlantic, thereby buoying the

price. Further, we do not know the cost structure for an Alaskan operation. Another important consideration that we ignore here

is the radical change in the mid-Atlantic’s management regime in 1990 from a time-restricted, quarterly TAC regime to an ITQ

regime. As a consequence, the application of the model to the pre-1990 surf clam market may be questioned.

16 Armitage’s model is an ex-vessel “price prediction” model that does not factor out supply effects explicitly. The model

tests the hypotheses that surf clam price is a function of surf clam landings, the demand for ocean quahogs, the demand for hard

clams, and the demand for oysters. The modified model specification and the parameter values used here are available from the

authors upon request.

17 The decrease in mid-Atlantic revenues is apportioned using the relative ratio of yield in each fishery. For example, the

Alaskan share is equal to 0.97 = 25,017mt/(25,017mt + 711mt). 
ed “Net” Gross Revenues Arising from Opening the Alaskan and Georges Bank Surf Clam Fisheries

(2000 dollars; gr rev = gross revenues)

(B) (C) (D) (E) (F) (G) (H) (I) (J)

CTUAL

 MIDATL

PRICE

ACTUALMID-ATL

GR REV

ESTIMATED

U.S.

PRICE

ESTIMATED

MID-ATL

GR REV

ESTIMATED

ALASKA

GR REV

ESTIMATED

GEORGES

BANK

GR REV

ESTIMATED

TOTAL U.S.

GR REV

NET

ALASKAN

GR REV

NET

GEORGES

BANK

GR REV

0.69 42,067,532 0.41 25,044,815 22,739,704 47,784,520 5,716,9870.66 41,184,360 0.42 26,204,755 23,268,262 49,473,017 8,288,657

0.63 42,290,924 0.39 26,341,452 21,660,517 615,432 48,617,401 6,151,691 174,786

0.58 41,301,457 0.32 22,700,343 17,695,807 502,784 40,898,934 -391,402 -11,121

0.55 36,272,435 0.36 23,909,371 20,064,403 570,083 44,543,856 8,042,902 228,5200.53 38,486,668 0.37 26,920,663 20,383,397 579,146 47,883,206 9,136,933 259,604

6,157,628 162,947
Economic Impact of HABs in the U.S.

42

fishery across both the Alaskan (column [I]) and Georges Bank column [J]) fisheries. Note that

this apportioning is conducted purely for accounting purposes at the national level. For

example, in 1987, the gross benefit to Alaska of a surf clam fishery is roughly $23 million, but

the contribution of an Alaskan fishery to the nation, given that demand is downward sloping, is

only about $6 million.

In 1990, the decline in gross revenues in the mid-Atlantic fishery is so substantial, that the “net”

contribution to total U.S. gross revenues from landings in the other fisheries is negative. During

the study period, the average HABs-related loss in gross revenues to the hypothetical Alaskan

surf clam fishery is approximately $6.16 million and to the hypothetical Georges Bank surf clam

fishery is $0.16 million (2000 dollars). We believe that these are much more realistic estimates

than the $50 million that is typically discussed.

4.2.2 Georges Bank Surf Clam Fishery

The Georges Bank surf clam fishery has been closed since 1989 due to high PSP levels.

Assuming this is a viable commercial fishery, the opportunity costs of closing the fishery could

be viewed as an estimate of the economic impacts of HABs. In 1990, the combined New England

and mid-Atlantic surf clam quota allowed by NMFS was 230 metric tons, valued at only $2.94

million (2000 dollars). Note that because individual surf clam quotas are not site-specific,

fishermen can switch at low cost to other regional locations, e.g., offshore New Jersey. As

explained in section 4.2.1, we estimate average annual economic impacts to be $0.16 million

(2000 dollars).

4.2.3 Georges Bank Roe-On Scallop Fishery

The traditional offshore scallop fishery in the U.S. sector of Georges Bank has not been affected

by HABs because the product, the scallop adductor muscle, does not concentrate PSP toxins.

However, the potential may exist for the development of a “roe-on-scallop” fishery (adductor

muscle with the gonad attached), because this product is highly regarded in much of the world.

The roe can accumulate PSP toxins, so such a fishery would be affected by the presence of the

toxins. A fishery for roe-on-scallops has existed in the Canadian sector of Georges Bank since

the late 1980s. The fishery is relatively small, involving about 5,000 lbs. of roe-on-scallop

landings per week (K. White, pers. comm., 1998). The fishery was closed from about 1992 to

1994 because of high levels of PSP toxins. The roe-on scallops are not marketed in Canada but

are sent overseas, bringing in substantially more revenue per pound than the adductor muscle

alone does (K. White, pers.comm., 1998).18

 

18 The unit price of the roe-on product is about $C15/lb overseas. In Canada, the exvessel value of the adductor muscle

alone is about $C 8-9/lb (K. White, pers. comm., 1998).
Economic Impact of HABs in the U.S.

43

It is unknown to what extent a similar roe-on-scallop fishery would be commercially viable in the

United States sector of Georges Bank. There is insufficient information about the international

demand for the product or of the logistics and expense of toxin testing protocols. We therefore

do not consider it meaningful to assess the economic impact of lost opportunities in this fishery

because of the lack of quantitative information. Nevertheless, it is conceivable that shellfish

poisoning is restricting the development of a U.S. roe-on-scallop fishery.

4.3 Major HAB Events in Other Years

This study focused on the years 1987-92, yet there were a number of significant events in other

years that demonstrate the magnitude of the impacts that are possible. For example, in 1976,

New Jersey suffered an extensive oxygen depletion event in which HABs were implicated in

part. A confluence of oceanographic, hydrologic, and meteorological factors led to a bloom of the

dinoflagellate Ceratium tripos, which resulted in anoxic conditions and the formation of hydrogen

sulfide in the bottom waters of the New York Bight. The bloom affected sedentary commercial

stocks of surf clams, ocean quahogs, sea scallops, and some finfish and lobster. Lost sales from

harvests during 1976 and for five to seven years into the future (for scallops and surf clams

respectively) were estimated. The largest impacts by far occurred in the surf clam market.

Impacts in the downstream processing and marketing sectors were estimated using a multiplier of

2.5. Total lost sales in all sectors combined were estimated to be $1.33 billion in 2000 dollars

(Figley et al. 1979).

In September 1980, the entire Maine coastline was closed to shellfishing because of a bloom of

the dinoflagellate Alexandrium tamarense, a source for PSP toxins. Harvest losses from this

event were estimated at $5.04 million, and total economic impacts were estimated to be $15.10

million, using a multiplier of 3 (2000 dollars). Also in 1980, California, Oregon, and Washington

closed oyster harvesting for one month due to PSP toxicity, resulting in losses to commercial

oyster growers in these states of $1.31 million (Nishitani and Chew 1988). In 1986, a red tide of

Gymnodinium breve event in Texas caused the loss of $2.22 million in oyster production,

resulting in estimated economic impacts of $6.00 million (2000 dollars) (Texas Shores 1987).

In 1997, a bloom of Pfiesteria occurred in several Chesapeake Bay tributaries. The bloom

resulted in the deaths of from 30-50,000 menhaden. After medical testing of fishermen who

complained of an array of physical and neurological problems, the Governor of Maryland

acknowledged the human health risk associated with Pfiesteria and closed several Chesapeake

tributaries to recreation and fishing (Bowman 1997). Although the state later spent half a million

dollars on a promotional effort to counteract the scare, demand for seafood from the state of

Maryland shrank significantly during the autumn of 1997. Lipton (1999) estimates $45.70

million in lost seafood sales to Maryland producers that can be attributed directly to the 1997

Pfiesteria scare (2000 dollars).
Economic Impact of HABs in the U.S.

44

5 RECREATION AND TOURISM IMPACTS

In 1991, a federal government study estimated that saltwater anglers spent an average of $562 per

angler, totaling $5 billion (1991 dollars) for travel, food, lodging and equipment (DoI and DoC

1993, Appendix D). When compared with the total U.S. domestic landings of commercial finfish

and shellfish ($3.3 billion in 1991), total recreational expenditures can be seen to be 67 percent

greater than commercial fish landings. However, to date, the economic impacts of HABs on

recreational and tourism activities have been given little attention relative to the impacts on

commercial fisheries.

Although many experts argue that the impacts of HABs on recreation and tourism are important

and potentially large, there are few available data describing the size of the impacts (Table 5.1).

Our estimates of the economic impacts on recreation and tourism during the 1987-92 period range

from zero to $29.30 million. The annual average is $6.63 million.

Table 5.1: Recreation and Tourism Impacts

(2000 $U.S. millions)

Year Incident Type State Estimated

Impacts

Annual

Total

Estimated

Impacts

1987 tourism and recreation

impacts to a coastal

community (red tide)

NSP North

Carolina

28.32 29.30

1988 0.00

1989 0.00

1990 0.00

Recreational shellfishing for

razor clams

1991 ASP Oregon 1.05

Recreational shellfishing for

razor clams

ASP Washington 0.66 1.71

Recreational shellfishing for

razor clams

1992 ASP Oregon 2.04

Recreational shellfishing for

razor clams

ASP Washington 6.72 8.76
Economic Impact of HABs in the U.S.

45

5.1 The 1987 North Carolina Red Tide Event

The overall impacts from a 1987 HAB event in North Carolina have been "conservatively"

estimated at $37.57 million (2000 dollars) (Tester et al. 1988). This estimate includes neither the

public health impacts nor monitoring and management costs. Because the losses to commercial

fish harvests from this incident were estimated at $8.27 million, we can attribute the remaining

$29.30 million to recreation and tourism impacts. The estimated tourism and recreation impacts

of the incident amounted to only 1.9 percent of the $1.52 billion (2000 dollars) generated by

combined hotel, lodging, amusement and recreation services in the entire state of North Carolina

in 1986.19 Nevertheless, we expect that the ratio of economic impacts to measures of county

productivity in the four impacted coastal counties is much larger. However, as tourists redirected

their vacation destinations, negative impacts that occurred in these four counties are likely to

have been counterbalanced by positive impacts in other counties, in North Carolina and

elsewhere, thereby mitigating aggregate impacts at the state or regional level.

5.2 The 1991-92 Washington and Oregon ASP Event

Another major HAB event that affected recreation and tourism activities occurred in Oregon and

Washington during 1991-92. In October 1991, these states closed their primarily recreational

razor clam fisheries because of ASP contamination. In Oregon, prior to the closures, roughly

67,000 trips per year were taken for recreational shellfishing of razor clams (Radke, pers. comm.,

1994). On average, recreational shellfishermen spend $30.51 per trip (2000 dollars). Therefore,

we estimate the 1992 economic impacts of the razor clam shellfish closure to be $2.04 million.

We assume that the 1991 impacts were a little more than one-half of this amount, $1.05 million,

because the onset of ASP contamination occurred during the fall of 1991.

In Table 5.2, we present the numbers of recreational shellfishing trips in Washington State for

razor clams during the spring and fall seasons before and after the outbreak of ASP (Ayres and

Simons 1993, 1992). The number of trips in the fall of 1991 fell by 21,333 compared with the

three-year average prior to the ASP event. In 1992, the combined number of trips made during

the spring and fall seasons was smaller by 220,666 compared with the three-year average. Using

an estimated average per trip expenditure of $30.51 for recreational shellfishing, we estimate the

impacts on recreation and tourism to be $0.66 million and $6.72 million in 1991 and 1992,

respectively.

 

19 Appendix C presents, for each coastal state, gross state product (GSP) and the value of output from several industrial

sectors within that state during 1985-90 (Trott et al. 1991).
Economic Impact of HABs in the U.S.

46

Table 5.2: Washington State Recreational Shellfishing Trips for Razor Clams

(before and after October 1991 ASP event)

Season Fall Spring

1988-89 43,000 195,000

1989-90 55,000 204,000

1990-91 32,000 274,000

Average (88-91) 43,333 224,333

1991-92 *22,000 0

1992-93 47,000 136,000

1993-94 60,000 --

*Fall 1991 season was cut short.

Source: Ayres and Simons (1993, 1992)

5.3 Recreational Impacts - Large but Uncertain

Many experts consider the economic impacts of HABs on commercial fisheries to be minor in

contrast with the size of the impacts on recreation and tourism. This is believed to be the case in

Florida, where Habas and Gilbert (1975) estimated the economic damage to the tourist industry

of a summer 1971 Gymnodinium breve red tide event at more than $68 million (in 2000 dollars).

Gymnodinium blooms have occurred after 1971, but there have been no attempts to estimate

economic impacts. The most significant impacts occurred in the hotel, restaurant, amusement,

and retail sectors. As with the North Carolina red tide event, we need to be careful in interpreting

these damage estimates. Undoubtedly some tourists spent their monies at other tourist

destinations in Florida or other states.

When kills of “trash” fish result from an HAB, there is no commercial fishery impact, but dead

fish can substantially reduce the recreational “experience” of visitors to these beaches. In Texas,

a severe HAB event was reported during the period from August to October 1986. Most of the

dead fish from this event were either trash or “underutilized” fish, but many of these washed up

on beaches, where they decayed. According to Texas Shore magazine (1987), this event resulted

in economic impacts on tourism and seafood sales. However, the gross impact was minimized

because the economy of many Texas coastal communities was already depressed. In fact, sales

tax proceeds from ten affected coastal counties for the months affected by the HAB indicate only

small overall impacts when compared with tax proceeds the year before.
Economic Impact of HABs in the U.S.

47

5.4 Laguna Madre Brown Tide

Although we expect some level of economic impact from an HAB event, the anecdotal evidence

sometimes can be contradictory. As an example, from May 1990 until recently, a brown tide

developed and then persisted for over 7 years in the Laguna Madre, along the southern coast of

Texas. Some professional sport-fishing guides reported that they lost many customers, but

others say that customers are still catching fish by changing fishing methods to cope with a

change in the water's transparency level. (Water was clear before the outbreak, so “sight casting”

was possible). The Texas Parks and Wildlife Department reported that their monthly fish stock

assessments indicate the same abundance of adult and juvenile fish in the Laguna Madre when

compared with the situation prior to the brown tide, and their sport harvest surveys reveal

unchanged levels of sport fishing catches (Spiller, pers. comm., 1994). The Laguna Madre

system had suffered two unusually hard freeze seasons, causing widespread fish kills prior to the

onset of the brown tide. Sport fishermen may have bypassed the Laguna Madre because of poor

fishing results at those times.

5.5 Property Value and Recreational Impacts of Macroalgae

In Massachusetts, local residents expressed several different opinions about the economic

impacts of a slimy, dark-brown macroalgae, Pillayella litoralis. Since 1987, the recurrent

accumulation of Pillayella in Nahant Bay and Broad Sound has been attributed to eutrophication

of Massachusetts Bay by the press and the general public, but this may be more easily related to

a unique hydrographic mechanism which carries this alga to shore and concentrates it on one

particular shoreline location. Pillayella’s abundant growth interferes with swimming, and it

generates a sulfurous, "rotten-egg" odor as it decomposes on beaches. The property values of

houses in the area could be reduced by the existence of these algae on beaches and their smell.

However, this effect was both variable and uncertain. One Nahant realtor told us that prices of

some of the houses she sold were depressed because of the algae. In particular, she speculated

that a house that sold for $300,000 could have been worth $325-350,000 if there had been no

Pillayella problem (1994 dollars). A second realtor did not think property values were affected

at all, and a third believed that there was a negative effect, but that because the housing market

had been depressed for some time, the actual sales data do not show an impact.

Macroalgae may also negatively affect recreational activities. One local Nahant resident told us

that the presence of Pillayella resulted in no differences in beach attendance rates. However,

observations of identical numbers of beach-goers does not necessarily imply that there has been

no recreational impact, because when beach or fishing conditions deteriorate, each recreationist’s

personal “enjoyment” may decline. Therefore, it is important to know by how much

recreationists value certain environmental conditions, instead of focusing on only the

participation rate. 
Economic Impact of HABs in the U.S.

48

Efforts to measure these types of recreation and tourism impacts must be undertaken at the local

level because local environmental and socioeconomic conditions are critical determinants of

changes in recreational benefits. Moreover, in their valuation attempts, analysts also should

incorporate the existence of substitute beaches or other recreation areas where tourists can visit.

Even if certain areas are affected by HABs adversely, recreationists may be able to visit other

nearby areas that offer similar recreational amenities. In such a case, regional economic impacts

may be minimal.
Economic Impact of HABs in the U.S.

49

6 MONITORING AND MANAGEMENT COSTS

In Table 6.1, we present our findings about the costs of monitoring and managing HABs. Annual

average monitoring and management costs total $2.09 million (2000 dollars) in the United States.

We were able to obtain annual estimates of monitoring and management costs from twelve states:

Alaska, California, Connecticut, Florida, Maine and New Hampshire (combined), Massachusetts,

North Carolina, New Jersey, New York, Oregon, and Washington. Many states experiencing

HABs, such as Texas, do not have a regular monitoring program for PSP or HABs. It is often the

case that water monitoring tasks, including PSP testing, are spread across different divisions of

state government, making it difficult to collect data on costs (Langlois, pers. comm., 1994).

Further, monitoring activities for both HABs and other water quality testing, such as shellfish

sanitation, often are conducted by the same experts. Consequently, it is difficult to factor out

those costs related specifically to HAB monitoring and management.

In addition to the annual monitoring and management costs incurred by coastal states, we report

other categories of costs in Table 6.1. For example, in Massachusetts, BlueGold Mussels, Inc.

spent approximately $6,000 per year (1994 dollars) conducting PSP tests on their own shellfish

products. We also present other estimates of the costs of monitoring or management related to

one-time or infrequent events including: survey and investigation costs for two specific HAB

events in New Jersey (Olsen, pers. comm., 1994); the cost estimate for a 3-month NSP event on

Florida's west coast (Roberts, pers. comm., 1994); and the ASP tests during the spring of 1994 in

Washington (Simons, pers. comm., 1994).20

Our estimate for monitoring and management costs in Florida includes the annual costs of beach

cleanups on the southwest coast of Florida. These costs are currently incurred primarily by each

of the eight counties along that coast. We have collected recent (1995-97) estimates of the costs

of beach cleanups for Sarasota County (Conn, pers. comm., 1998). These costs average $56,592

per year (current dollars), and they apply to the cleanup of dead fish due to HAB events and to

the collection and disposal of red seaweed that washes up during storms. A significant portion of

the annual costs is the tipping fee. We divide this average cost by the number of miles cleaned

(17.5) in Sarasota County to develop a per mile cleanup cost. We assume that approximately 50

miles of the 200-mile southwest coast of Florida are cleaned each year, accounting for the

patchiness of red tide events and the difficulty of accessing certain areas of the coast. The result

is an estimate of the cost of beach cleanups for HAB events and washed up seaweed of about

$162,500 per year (1998 dollars). Further research will allow us to refine that estimate. Note

that Habas and Gilbert (1975) estimated the cleanup costs for a 1971 red tide event to be

approximately $755,211 in 2000 dollars.

 

20 This expenditure was for the spring season only. Apparently a budget shortfall precluded further ASP tests in the fall season

of 1994 (Simons, pers.comm., 1994).
Economic Impact of HABs in the U.S.

50

Table 6.1: Annual Average Monitoring and Management Costs

(2000 $U.S. thousands)

State Type of Cost

Annual

Average Cost

($000)

Alaska Estimated fees for PSP and ASP costs 320.74

California Annual monitoring 212.73

Connecticut Annual monitoring 10.11

Florida Personnel salaries and associated overhead

for monitoring and bioassaying for a 3-

month Gymnodinium breve event on west

coast; estimated costs for beach clean-ups

during each year

183.59

Maine/New Hampshire Annual PSP monitoring 291.61

Massachusetts Annual monitoring; Annual private PSP

monitoring by BlueGold Inc. (400 samples

annually at $15 per sample)

57.79

New Jersey A series of three tests for annual red tide

monitoring at $100 per test; individual

response investigations by four separate

agencies for a Jun-Aug 1988 algal bloom;

intensive follow-up survey conducted in

1989 for the Jun-Aug 1988 bloom;

individual response investigations by two

agencies for a July 1992 algal bloom

30.30

New York Annual monitoring 319.10

North Carolina Annual monitoring 34.84

Oregon Annual monitoring 96.26

Washington Annual monitoring 531.83

TOTAL 2088.89
Economic Impact of HABs in the U.S.

51

7 CONCLUSIONS AND FUTURE RESEARCH NEEDS

7.1 Annual Aggregate Economic Impacts

Table 7.1 (which reproduces Table ES-1), is a compilation of our estimates of the annual

aggregate economic impacts (in millions of 2000 dollars) of HABs in the United States during the

1987-92 period. For each of the four main types of impacts, we present both the ranges of

annual estimated impacts during the 1987-92 study period and average annual estimated impacts.

Public health impacts are the largest component, representing about 45 percent of total average

impacts at more than $22 million annually. Impacts from ciguatera poisonings are the largest

element of those public health impacts. Commercial fisheries impacts are the next largest

component, representing 37 percent of total average impacts at more than $18 million annually.

Recreation/tourism impacts account for 13 percent of total impacts at nearly $7 million annually.

Monitoring/management costs represent only 4 percent of the total at more than $2 million

annually. It is important to note that expenditures made to improve monitoring and management

likely resulted in decreases in impacts in the other categories.

We also present an estimate of capitalized impacts. Assume that our estimates of impacts will

occur on an annual basis over the next 15 years. Discounting these annual losses at a rate of 7

percent and summing the discounted losses results in an estimate of capitalized impacts. Our

estimate of 15-year capitalized average impacts is $449 million. 

During the 1987-92 period, total annual impacts fluctuated widely (except for

monitoring/management costs). This reflects the irregular occurrence of HAB events, which in

turn vary dramatically with respect to the magnitude of impacts. We expect that coastal

communities and industries are able to manage recurrent (i.e., expected or “predictable”)

outbreaks reasonably well, thereby limiting their economic impacts (Shumway et al. 1988).

However, outbreaks of unexpected or unusual blooms may tend to cause more severe economic

impacts (Bicknell and Walsh 1975; Egan 1990; Tester et al. 1988).

7.2 Reasons Why Our Estimates are Conservative

The estimates reported here represent a preliminary approximation of the economic costs to the

United States from the occurrence of HABs. The fact that these estimates are uncertain or

approximate is not due to lack of effort, but rather to the difficulty in assigning impacts to many

of the events that occurred – due to lack of information and even to a lack of knowledge as to

how to quantify certain impacts. Due to reporting inadequacies and the large size of the US

coastline, the HAB events on which this analysis is based are a subset of all outbreaks that

occurred during the 1987-92 window. Consequently, our aggregate economic impact

underestimates the actual impacts. A second qualification is that, although we report on economic
Estimated Annual Economic Impacts from Harmful Algal Blooms (HABs) in the United States

(Estimate is of 1987-1992 period, reported in 2000 dollars)

% of 

Low High Average Total

$ 18,493,825 $ 24,912,544 $ 22,202,597 45%

hery $ 13,400,691 $ 25,265,896 $ 18,407,948 37%

ism $ - $ 29,304,357 $ 6,630,415 13%

agement $ 2,029,955 $ 2,124,307 $ 2,088,885 4%

$ 33,924,471 81,607,104 $ 49,329,845 $ 100%

zed Impacts

%) $308,981,162 $743,270,485 $449,291,987
53

impacts, we did not use economic multipliers. Thus, our estimates reflect only the direct effects

of HAB events, ignoring indirect and induced effects on other sectors of the economy. Again, this

conservative approach leads to underestimates of the true impact.

Human sickness and death from eating tainted seafood results in lost wages and work days and

pain and suffering. Costs of medical treatment and investigation are also an important aspect of

the economic impact caused by such events. We know that a substantial number of illnesses

caused by HABs remain unreported. In the absence of a reliable method for estimating the actual

number of illnesses, we adopted conservative “rule-of-thumb” factors from several experts in the

field. Further, we used estimates developed by Todd of the costs of shellfish and ciguatera

poisoning -- estimates that are smaller, by an order of magnitude, than generic estimates of

nonfatal illness costs emerging from studies of job risks. 

Our public health impact estimates are dominated by ciguatera illness and treatment costs, but

these estimates are low because ciguatera poisoning also occurred outside of the areas we

surveyed as a result of exports of tropical fish to other jurisdictions. In addition, we have been

unable to include either the costs of insurance to cover potential ciguatera-caused liabilities or the

court costs associated with ciguatera-related litigation. 

Commercial fisheries impacts underestimate true losses due to HAB events because they do not

include PSP closures in several states, including Maine and Massachusetts, where it was not

possible to document the acreage closed or the value of the resource that was not harvested

during PSP outbreaks. These states are examples of the case where the price of shellfish may

increase when landings are lowered due to closures. Indeed, the economic impact estimate from

harvesting closures (basically the increased value of output), would appear to be positive—a

counterintuitive result. Although some shellfishermen may benefit from price increases,

consumers unambiguously lose. These losses are not included in our economic impact estimates,

because once again, it is difficult to quantify them. Furthermore, our estimates do not include the

costs of wild fish kills, because the value of those fish is not known in most cases.

Another factor that leads to an underestimate of impacts is the economic loss from blooms of

Pfiesteria or Pfiesteria-like organisms that have not been included in our totals. Although recent

Pfiesteria blooms have been shown to have major economic halo effects in Maryland following an

outbreak in 1997 (Seiling and Lipton 1998), the organism had not been identified during the early

portion of our study period, and even after it was first linked to massive fish kills, no estimates

could be obtained of the economic losses associated with those events. In part this reflects the

difficulty in attributing causality to past fish kills and in assigning economic value to wild fish.

Yet another conservative aspect of this study is that some currently untapped fishery resources

have values that might be realised in the absence of HAB events, but such estimates are not

included here. Examples include some shellfish resources of coastal Alaska, which are

permanently quarantined due to persistent toxicity and the logistics of sampling distant or remote

resources (Neve and Reichardt 1984), and a potential roe-on scallop fishery on Georges Bank.
54

Finally, although many experts argue that the impacts of HABs on recreation and tourism are

important and potentially large, there are few available data describing the size of the impacts.

For example, reduced tourism and lowered residential real estate values on the Gulf Coast of

Florida are two types of impacts that are likely to be large but for which we currently have no

data. 

7.3 Information Needs

In addition to economic impact estimates, we made several important findings about the current

state of available information and the need for improvements in the data collection process. First,

the reporting practice of HAB events needs to be expanded and the format formalized. At

present, information about HAB events is fragmentary and incomplete in its coverage. HAB data

are compiled on an annual basis by the U.S. National Office for Marine Biotoxins and Harmful

Algal Blooms at the Woods Hole Oceanographic Institution. These data are maintained by that

office, and are also supplied to the ICES/IOC Working Group on Harmful Algal Bloom

Dynamics, which has entered them into an international database called HAEDAT (Harmful

Algal Events Database), maintained by the IOC HAB Science and Communication Centre in Vigo

Spain. However, the data collection effort within the different reporting regions of the US relies

on volunteer efforts by academic and government scientists as well as government officials, and

thus tends to be uneven in coverage and detail. Efforts are underway to standardize the data

collection process, but even with those changes, it is clear that these individuals cannot provide

the type of information needed for economic impact assessment. At the least, the duration,

affected acreage or shoreline length, average toxicity levels, and values of affected coastal

resources should be documented for each bloom in order to describe the overall economic

significance of the incident. In addition, local and state governments should place much higher

emphasis on quantification of economic impacts. Economic impacts are usually specific to local

environmental and socioeconomic conditions, and local officials are therefore the ones who need

to compile the information which can later be analyzed by economists. Until local governments

become capable of supplying site-specific impact information for each bloom incident, truly

comprehensive and detailed national level aggregation of such impacts cannot be realized.

Second, we note that some economic information is available on economic impacts to fisheries

resources or to human populations exposed to HABs, but there is a significant lack of available

information about recreation and tourism impacts. This could be a significant but highly episodic

factor that is presently underestimated in our study.

Third, the causes of economic impacts and the degree of their uncertainty should be included in

any study of economic impacts. For example, it may be premature to attribute the economic

impacts solely to a specific HAB, because there are often other possible explanations for

mortality events. Finally, economic factors that are used to generate the impact estimates should
55

be reported. These factors include whether or not an economic multiplier is used; local economic

recession or prosperity trends; and foreign and domestic seafood competition factors.

7.4 Overview

Here we offer the first effort to compile an estimate of the economic impact of HABs in the US.

The data generated are of interest and use, but it is also of note that the process of collecting,

compiling, and analyzing that data revealed areas where changes are needed. This includes

changes in the reporting process, as well as the development of new approaches to the

assignment of impacts to certain types of events or situations (e.g., the evaluation of unexploited

fisheries, or the losses associated with quarantine or harvesting restrictions). 

Overall, the economic impacts from HABs are diverse and large. Even with the highly

conservative treatment given the impacts in this study, the annual costs are significant. Average

annual costs also tend to mask the significance of individual HAB events, some of which greatly

exceed the annual average for the entire country. Perhaps more importantly, HABs are recurrent,

and show signs of increasing as the number of toxic and harmful algal species grows and as our

reliance on the coastal zone for aquaculture, commerce and recreation expands. Prudent

investment in research and monitoring can do much to reverse this trend and to reduce the annual

impacts.
56

8 REFERENCES

Ahmed, F.E., (Ed.). 1991. Seafood Safety. The Institute of Medicine, National Academy Press,

Washington, D.C.

Alaska Department of Fish and Game (ADF&G). 1996-99. Commercial Fisheries and Wildlife

Notebook Series. http://www.cf.adfg.state.ak.us/geninfo/.

Anderson, D.M. 1989. Toxic algal blooms and red tides: a global perspective. In: Red Tides:

Biology, Environmental Science, and Toxicology, T. Okaichi, D. Anderson, and T.

Nemoto (Eds.), Elsevier Science Publishing Co., Inc.

Anderson, L.G. 1986. The Economics of Fisheries Management. 2nd edition. Baltimore: Johns

Hopkins University Press.

Archer, B. 1995. Economic impact analysis. Research Notes and Reports, 704-707.

Armitage, T.M. 1985. A bioeconomic model of the middle Atlantic surf clam (Spisula

solidissima) fishery. Ph.D. Dissertation. Williamsburg, Va.: School of Marine Science,

College of William and Mary.

Ayres, D.L. and D.D. Simons. 1992. The 1991 razor clam fisheries and status of the razor clam

stocks, Progress Report No. 300, September, Department of Fisheries, State of

Washington.

Ayres, D.L. and D.D. Simons. 1993. The 1992 and 1993 razor clam fisheries and status of the

razor clam stocks, Draft Progress Report, December, Department of Fisheries, State of

Washington.

Bicknell, W.J. and D.C. Walsh. 1975. The first 'HAB' in recorded Massachusetts history:

managing an acute and unexpected public health emergency. In: Proceedings of the First

International Conference on Toxic Dinoflagellate Blooms, V. R. LoCicero (Ed.), The

Massachusetts Science and Technology Foundation.

Bowman, B. 1997. Maryland governor: Pfiesteria can hurt people. WRAL5 Online (1

September): http://www.wral-tv.com/news/wral/1997/0901-maryland-governor/.

Department of Commerce and Department of the Interior (DoC and DoI). 1993. 1991 national

survey of fishing, hunting, and wildlife-associated recreation. Washington: U.S.

Government Printing Office (March).

Egan, B. D. 1990. All dredged up and no place to go. AAC Bulletin, No. 90-1, pp. 7-15.

Figley, W., B. Pyle and B. Halgren. 1979. Socioeconomic impacts. Chapter 14. In: Oxygen

Depletion and Associated Benthic Mortalities in New York Bight, 1976, R.L. Swanson and

C. J. Sindermann (Eds.), Professional Paper 11, December, NOAA, U.S. Department of

Commerce.

Foster, N.R. 1997. The molluscan fisheries of Alaska. pp. 131-144 In History, Present

Condition, and Future of the Molluscan Fisheries of North Central America and Europe,

C.L. MacKenzie, V.G. Burrell, A. Rosenfield and W.L. Hobart, (Eds.), Vol. 2, Pacific

Coast and Supplemental Topics. Woods Hole, Mass.: Northeast Fisheries Science

Center, National Marine Fisheries Service, National Oceanic and Atmospheric

Administration, U.S. Department of Commerce.
57

Gorte, Ross W. 1994. The Florida bay economy and changing environmental conditions. 94-435

ENR, CRS Report for Congress, Congressional Research Service, The Library of

Congress.

Habas, E. J., and C. Gilbert, 1975. A preliminary investigation of the economic effects of the

HAB of 1973-1974 on the west coast of Florida. In: Proceedings of the First

International Conference on Toxic Dinoflagellate Blooms, V. R. LoCicero (Ed.), The

Massachusetts Science and Technology Foundation.

Hallegraeff, G.M. 1993. A review of harmful algal blooms and their apparent global increase.

Phycologia 32:79-99

Hughes, S.E. and N. Bourne. 1981. Stock assessment and life history of a newly discovered

Alaska surf clam (Spisula polynyma) resource in the southeastern Bering Sea. Canadian

Journal of Fisheries and Aquatic Sciences 38(10): 1173-1181.

Hughes, S.E. and R.W. Nelson. 1979. Distribution, abundance, quality, and production fishing

studies on the surf clam, Spisula polynyma, in the southeast Bering Sea, 1978. NWAFC

Proc. Rep. 79-4. Anchorage, Ak.: Northwest Alaska Fisheries Center, National Marine

Fisheries Service, National Oceanic and Atmospheric Administration, U.S. Department of

Commerce.

Hunter, W.J. 1989. Economic-impact studies: inaccurate, misleading and unnecessary.

Industrial Development 158(4): 10-16.

Jewett, S.C. and H.M. Feder. 1981. Epifaunal invertebrates of the continental shelf of the

eastern Bering and Chukchi Seas. In: The Eastern Bering Sea Shelf: Oceanography and

Resources. Vol. 2. D.W. Hood and J.A. Calder, (Eds.), Washington: Office of Marine

Pollution and Assessment, National Oceanic and Atmospheric Administration, U.S.

Department of Commerce and Bureau of Land Management, U.S. Department of the

Interior.

Kahn, J. and M. Rockel. 1988. Measuring the economic effects of brown tides. Journal of

Shellfish Research, Vol. 7, No. 4, pp. 677-682.

Lipton, D.W. 1999. Pfiesteria's economic impact on seafood industry sales and recreational

fishing. In: Proc. Economics of Policy Options for Nutrient Management and Pfiesteria.

B.L. Gardner and L. Koch, (Eds.), College Park, Md.: Center for Agricultural and Natural

Resource Policy, University of Maryland, College Park, pp. 35-38.

Loomis, J.B. 1993. Integrated public lands management: principles and applications to national

forests, parks, wildlife refuges, and BLM lands. New York: Columbia University Press,

Chap. 7, pp. 171-191.

Lutz, R.A. and L.S. Incze. 1979. The impact of toxic dinoflagellate blooms on the North

American shellfish industry. In: Toxic Dinoflagellate Blooms, D. Taylor and H. Seliger,

(Eds.). Elsevier, New York.

National Marine Fisheries Service (NMFS). 1985-1992. Fisheries of the United States. Silver

Spring, Md.: NOAA, U.S. Department of Commerce.

National Oceanic and Atmospheric Administration (NOAA). 1989. Selected characteristics in

coastal states: 1980-2000. NOAA's Coastal Trends Series: Report 1. Silver Spring, Md.:

NOAA, U.S. Department of Commerce (October).
58

National Oceanic and Atmospheric Administration (NOAA). 1990. 50 years of population

change along the nation's coasts: 1960-2010. Silver Spring, Md.: Strategic Assessment

Branch, NOAA, U.S. Department of Commerce (April).

National Oceanic and Atmospheric Administration (NOAA). 1991a. The 1990 national 

shellfish register of classified estuarine waters. Silver Spring, Md. : Strategic Assessment

Branch, NOAA, U.S. Department of Commerce (July).

National Oceanic and Atmospheric Administration (NOAA). 1991b. Fish kills in coastal

waters: 1980-1989. Silver Spring, Md.: Strategic Environmental Assessments Division,

NOAA, U.S. Department of Commerce (September).

Nelson, R.W., J.C. Wekell and J.W. Joy. 1979. Evaluation of the clam resources of the S.E.

Bering Sea. Proc. National Shellfish Association 69: 204.

Neve, R.A. and P.B. Reichardt. 1984. Alaska's shellfish industry. In: Seafood Toxins, E.P.

Ragelis, (Ed.), Washington: American Chemical Society, pp. 53-58.

Nishitani, L. and K. Chew. 1988. PSP toxins in the Pacific Coast states: monitoringprograms

and effects on bivalve industries. Journal of Shellfish Research 7(4): 653-669.

Orth, F.L., C. Smelcer, H.M. Feder, and J. Williams. 1975. The Alaska clam fishery: a survey

and analysis of economical potential. University of Alaska Institute of Marine Science

Report No. R75-3 and Alaska Sea Grant Report No. 75-05. Fairbanks: Alaska Sea Grant

College Program, University of Alaska (August).

Pielke, R.A. and C.W. Landsea. 1997. Normalized hurricane damages in the United States: 1925-

1995. Mimeo. Boulder, Colo.: Environmental and Societal Impacts Group, National

Center for Atmospheric Research.

Pielke, R.A., Jr. and R.A. Pielke, Sr. 1997. Hurricanes: their nature and impacts on society.

New York: John Wiley & Sons.

Propst, D.B. and D.G. Gavrilis. 1987. Role of economic impact assessment procedures in

recreational fisheries management. Trans. Am. Fish. Soc. 116: 450-460

Ragelis, E.P. 1984. Ciguatera seafood poisoning: overview. In: Seafood Toxins, E.P. Ragelis,

(Ed.), Washington: American Chemical Society, pp. 25-36.

Ralonde, R. 1998. Harmful algal blooms: the economic consequences for Alaska. Mimeo.

Fairbanks: University of Alaska Marine Advisory Program.

Rippey, S.R. 1994. Shellfish borne disease outbreaks. Shellfish Sanitation Program Technical

Report. North Kingstown, R.I.: Northeast Seafood Laboratory Branch, U.S. Food and

Drug Administration.

Rose, J.C. 1987. Scallops transplanted to algae-damaged beds. Oceans 20(1): 6.

Ruff, T.A. 1989. Ciguatera in the Pacific: a link with military activities. The Lancet (28

January): 201-205.

Schink, T.D., K.A. McGraw and K.K. Chew. 1983. Pacific coast clam fisheries. WSG 83-1.

Seattle, Wash.: Washington Sea Grant Program, College of Ocean and Fishery Sciences,

University of Washington, pp. 33-40.

Shumway, S.E, S. Sherman-Caswell and J. W. Hurst. 1988. Paralytic shellfish poisoning in

Maine: monitoring a monster. Journal of Shellfish Research 7(4): 643-652.

Shumway, S.E. 1990. A review of the effects of HABs on shellfish and aquaculture. Journal of

the World Aquaculture Society 21(2): 65-104.
59

Smayda, T.J. 1990. Novel and nuisance phytoplankton blooms in the sea: evidence for a global

epidemic. In: Toxic Marine Phytoplankton. E. Graneli et al., (Eds.), Elsevier Science

Publishing Co., Inc., pp. 213-228.

Stoker, S.W. 1977. Report on a subtidal commercial clam fishery proposed for the Bering Sea.

MMC-77/01. Washington: U.S. Marine Mammal Commission.

Suffolk County Department of Health Services (SCDHS). 1992. Brown tide comprehensive

assessment and management program: summary. New York (November).

Tester, P.A., R.P. Stumpf and P.K. Fowler. 1988. HAB, the first occurrence in North Carolina

waters: an overview. In: Proc. of the Oceans '88 Conference. Baltimore: Marine

Technology Society, pp. 808-811.

Tester, P.A., R.P. Stumpf, F.M. Vukovich, P.K. Fowler, and J.T. Turner. 1991. An expatriate

red tide bloom: transport, distribution, and persistence. Limnol. Oceanogr. 36:1953-1061. 

Tettelbach, S. and P. Wenczel. 1993. Reseeding efforts and the status of bay scallop Argopecten

irradians (Lamarck, 1819) populations in New York following the occurrence of “brown

tide” HABs. Journal of Shellfish Research 12(2): 423-431.

Texas Shores. 1987. Vol. 19, No. 4. College Station, Texas.: Sea Grant College Program, Texas

A&M University.

Todd, E.C.D. 1995. Estimated costs of paralytic shellfish, diarrhetic shellfish and ciguatera

poisoning in Canada. In: Harmful Marine Algal Blooms, P. Lassus et al., (Eds.) Lavoisier

Intercept Ltd., pp. 831-834.

Todd, E.C.D. 1989a. Preliminary estimates of costs of foodborne disease in the United States.

Journal of Food Protection 52(8): 595-601.

Todd, E.C.D. 1989b. Costs of acute bacterial foodborne disease in Canada and the United States.

International Journal of Food Microbiology 9: 313-326.

Trott, E.A., A.E. Dunbar and H. L. Friedenberg. 1991. Gross state product by industry: 1977-

89. Survey of Current Business 71(12): 43-59.

Viscusi, W.K., W.A. Magat and J. Huber. 1987. An investigation of the rationality of consumer

valuations of multiple health risks. Rand Journal of Economics 18(4): 465-479.

Viscusi, W.K. 1993. The value of risks to life and health. Journal of Economic Literature 31:

1912-1946.

Weninger, Q. 1998. Assessing efficiency gains from individual transferable quotas: an

application to the mid-Atlantic surf clam and ocean quahog fishery. American Journal of

Agricultural Economics 80: 750-764.

White, A.W., J. Nassif, S.E. Shumway and D.K. Whittaker. 1993. Recent occurrence of

paralytic shellfish toxins in offshore shellfish in the northeastern United States. In: Toxic

Phytoplankton Blooms in the Sea, T. Smayda and Y. Shimizu (Eds.), Elsevier Science

Publishers, pp. 435-440.
60
APPENDIX A

Harmful Algal Bloom Incidents

Thi s Appendix is a summary of harmful algal bloom incidents reported infor mally

from coastal st ates t o the Natio nal Of fice f or Marine Bio toxins and H armful 

Alg al Blo oms atthe Woods H ole Oceanographic Instit ution for the 1987 - 1992

per iod.
Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

hor es, AL "Bloom" o f filamentou s algae heav ily

inf ested front beaches; over 2,00 0,000dead menh aden f ound in vicinity o fState Par k Pier . Cou ld not tie the two occurrences tog ether since waterquality h ad returned to nor malfollowing the k ill.

Cla dophor a sp .
ocation/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

 Cove n ear

kan 

PSP , 41-y ear old female fro m threesteamed clams

War ning about P SP and uncertified areas

Alexandrium 61μ g/100g (the sample of co oked

clams)

Island; A rea no t

d (no commercial

); harvest for 

en ce pur poses

4 p eople had PS P symp tom (3 cases ) Sam ples o f butter clams and 

oth ers to be an alyzed for P SP

 Lagoon 1 p erson had PS P symp toms f rom

fried cockles

Sam ple to be an alyzed forPSP 

kan ; from Blashke

(approved oyster

m harves t area)

1 p erson reported PSP typesym ptoms, but u nknown cause

Res ampled little neck clams wer e negative f or PSP anddom oic acid

o Bay (SW end o f

an Penins ula), 28

E o f village of Cold

One death , 47-y ear old male;con sumed 35-40 butter clams 

Two press releases statingris k of h arvesting fr omunapproved areas(recreational b eaches )

Alexandrium 7,7 50 psp /100g (butter clam s)

k Is land One indiv idual sought medical

ass istance after experiencingnum bness in face and later in his legs(co nsumed 20 mu ssels) 

Press release w arning abouthar vestin g in u ncertifiedareas

Alexandrium mus sel PS P, 1,9 25 and 2,026 μg/10 0g

Har bor, A laska

ula

No effects to 3 adults and 2 childrenwho ate cooked razor clams; a cat atevis cera ( guts), was p aralyzed and sub sequen tly died

No area o n Aleu tian I slands is certif ied co mmercially f orshellfish ing

 Peninsula, 16

ENE of Chignik

PSP ; 3 people h ospitalized(co nsumption of butter clam , muss elsand cockels)

a n on-cer tified area, not anapp roved commer cialshellfish ing ar ea

367 .2 μg/100g ( cockels); 85.0 μg/100 g(littleneck clams); 3 265.9 μg/100 g(mu ssels) 

coloration an d toxicity d etection at uncertified areas withou t any advers e effects were excluded.
Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

ma Co unty,

ga Harbor

PSP in th e Wash ington clam The Calif . Annu al

Quarantin e was extend ed toinclude the Was hingto nclam even beyon d thenor mal qu arantine per iod

Alexandriumcatenella 

120 μg/10 0g (siphon) and 54 μg/10 0g(viscera) in Ap r; 200 μg/10 0g (siphon)and 150 μ g/100g (viscera) in Jul; 120μg (sipho n) and 100 μ g (vis cera) inNov 

oin t, Son oma

y

PSP , 11 p eople affected (3 severely, 1critically) fro m sea mussels

2,0 00 μg/100g

Cru z Sick and dying brown pelicans and 

Brandt's cormor ants ( dom oic acid)

Nitzschia pseudoser iata(Ps eudo-nitzschia aus tralis )

100 -200 ppm (dom oic acid in stomach);50- 60 ppm (dom oic acid in body p arts)

ocino County Hig h PSP in wild sea mussels Ann ual qu arantine was 

extended indefinitely 

Alexandriumcatenella 

PSP , 930 μg/100 g (Jul); up to 330 0μg/100 g

ma Co unty Hig h PSP toxin levels in Wild Sea

Mus sels, Washin gton Clam, andBas ket Co ckle

A s pecial quarantine wasestablish ed to includ e allbiv alve s hellfish tak en byspo rt har vester s.

Alexandriumcatenella 

330 0μg/10 0g (wild sea mussels); 1 00-1,4 00 μg/100g ( Washin gton Clam); 130μg/100g ( Basket Cockle)

 Cou nty Hig h PSP in mus sels, oyster s, and 

clams

A s pecial quarantine orderto includ e all bivalv eshellfish taken by sp orthar vester s. Th e annu alquarantin e on s porthar vested mussels was extended indefinitely ;Drakes Bay and the en tireEstero were clo sed to com mercial harv esting onJul 26.

Alexandriumcatenella 

1,9 00-10,000 μg /100g (mussels); 1 10-2,5 00 μg/100g ( clams) ; 1,20 0-2,20 0μg/100g ( oyster s)
C ontinued)

Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

 Cou nty (D rakes

himn ey Rock;

s Estero Beds #12 ,

Keh oe Beach;

les Bay Clam

; and Law son's

ng)

Hig h PSP in wild sea mussels, sen tinelsea mussels, bay wild mussels, gap erclams, cu ltured pacif ic oys ters

Emergency quarantineiss ued fo r Mar and Ap r onspo rt har vested mussels(persons collecting clamsand scallops ad vised todis card v iscera or dark par tsand only white meat b eprepared for hu mancon sumption).

Alexandriumcatenella 

PSP , 160 μg/100 g (max ) for Mar-Ap r;580 μg/10 0g (max) for Aug-N ov

ouis Obisp o

y (Moonsto ne

 Cam bria)

PSP in wild sea mussels Emergency mussel

quarantin e from Dec 1 989was still in ef fect. It was lif ted on Feb 1 3, 199 0.

Alexandriumcatenella 

PSP , 82 μ g/100g 

oldt County ;

ted areas were

oldt Bay (Mad

 Bird Isl., Ind ian

han ., San d Isl.,

 Jetty #1 & #2,

m. Gro w Station,

r Cove, Trinidad

 Trinidad Pier,

a Bridge (center

Extremely elevated co ncentr ations ofpar alytic toxin s in m ussels and o ysters 

Although the an nual m usselquarantin e was in eff ectdur ing th e bloo m, anemergency quarantine wasinitiated for clams, scallo ps,native oy sters, cockles, an doth er biv alves. Thequarantin e was extend edbey ond th e Oct 31 nor maldeadline to Nov 30, 1 989.

Alexandriumcatenella 

par alytic toxin s in s entinel (350 0 μg)wild (220 0μg) b ay mus sels; wild ( 4400μg) sentinel (1 4000 μ g) sea mussels;cultured Pacific oysters (2 70 μg) 

ocino County;

ted areas were

l Po int, A nchor

Cas par Po int,

 Cas par

ands ,

erricher State

Pt. Arena

hous e.

Par alytic toxin s; two non fatal cases ofPSP (one adult and on e two years oldchild) reported on 9/10. Both hadeaten mus sels collected at Anchor Bay .

The annual muss elquarantin e was in for ce, bu temergency quarantine wasins tituted in m id Sep t on thetak ing of clams , cock les,scallops, nativ e oysters, andoth er biv alves along thenor th coast.

Alexandriumcatenella 

Par alytic toxin s in w ild sea muss elsreached 6 300 μg /100g
C ontinued)

Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

ma Co unty;

ted areas were

lhou se Beach,

ga Bay South Jetty,

ga Head, Mu ssel

 Salt Point State

Dun can

Wrights' Beach,

anch /Black point

Increased paralytic s hellfish tox inlev els in natur al sea mussels and abalone jingle

Quarantin e on s porthar vestin g of m ussels dur ing Jan and Feb; thequarantin e extended the Oct31 deadline; pu blic P SPalert via news media

Alexandriumcatenella 

PSP from Aug th rough Oct reached550 0 μg/1 00g (w ild bay muss el), 1 900μg/100g ( wild s ea mus sel) and 220 0μg/100g ( sentin el bay mussel)

 Cou nty; A ffected

wer e Drak es

 ar eas #1 2 #17,

s Bay Chim ney

Boat Launch,

e Beach, Stinson

, Tom ales Bay

on's Landin g

PSP in sh ellfis h (sen tinel bay mu ssels,natural b ay mus sels, sentin el seamus sels, natural sea mussels, pacificoys ters, sentin el Jap anese scallo ps,gap ers clams (v iscera)

Clo sure o f comm ercialshellfish eries; emerg encyquarantin e on s porthar vested shellfish f rom th eentire Mar in Cou ntycoastline (quar antine liftedon Mar 20 )

Alexandriumcatenella 

 Cou nty; A ffected

wer e Drak es Bay 

ney Rock, D rakes

 Ar ea (#7 , #8,

20, #38),

ntour Beach ,

les Bay (Tom ales

 Lawson's 

ng, lease M430-

odeo Beach (hig h

w r ock)

Hig h PSP Iss ued pu blic P SP alert via

the news media. Since theann ual mu ssel q uarantinewas still in ef fect, theimp ortance of complyingwith it w as str essed.

Alexandriumcatenella 

180 0 μg/1 00g (J apanes e scallop); 360μg/100g ( cultur ed Pacific o yster) ; 1500 μg/100g ( cultur ed bay mussel); 90 0 μg(wild bay mussel); 18 00 μg (sentinelsea mussel); 21 0 μg ( wild s ea mus sel);460 μg (u nidentified mussel)
C ontinued)

Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

Mateo County;

ted areas were

 Mar , Moss Beach ,

dero State Beach ,

as Creek

Hig h PSP in wild sea mussels (800 μg/100g)

Ann ual mu ssel q uarantinewas exten ded beyond theOct 31 deadline; public PSP alert iss ued

Alexandriumcatenella 

800 μg/10 0g (wild sea mussels)

erey County ;

ted areas were

c G rove P oint

 Pf eiffer Beach 

ur 

Slight elevatio n in P SP in wild s eamus sels ( 110 μg /100g) in Au g and inDec (130 μg)

Ann ual mu ssel q uarantinewas in ef fect; emergencyquarantin e issu ed in Dec

Alexandriumcatenella 

110 μg/10 0g in Aug; 1 30 μg/100g inDec

ouis Obisp o

y; A ffected areas

Mor o Bay,

stone Beach ,

ria, North Estero

Estero Bay

os

Elevated PSP in cultu red an d wild baymus sels, wild s ea mus sels, andcultured pacific oysters

The annual muss elquarantin e (5/1 -10/31 ) wasin effect; emer gencyquarantin e was issued inDec; comm ercial oysteroperation s in Mor o Baywer e shut down

Alexandriumcatenella 

< 1 600 μg /100g (sea m ussels ); < 5 40μg/100g ( oyster s)

Bar bara County;

ted areas were

an Beach, Minute

Beach , Santa

ra Channel

Detectable but below alert levels ofPSP throu ghout the year in cultur edand wild bay mu ssels as well as inwild sea mussels; PSP in wild seamus sels exceeded the alert level in Octand Dec

Mus sel qu arantine was iss ued in Dec

Alexandriumcatenella 

s Estero Ar ea 17

rakes Bay, Mar in

y

PSP toxin in co mmercial mus sel beds Area clos ed to commer cial

har vestin g

Alexandriumcatenella 

87 vg/100 g (Drakes Estero baymus sels); 290 μ g/100g (Drak es Bay sen tinel Sea mu ssels) 

alert level (8 0μg/10 0g) or high levels within the Califo rnia annual quaran tine p eriod (May 1 - Oct 31) w ere ex cluded . These events did not lead to any

nts were not entered .
Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

 of G roton Hig h PSP in mus sels shellfish closu re (fo r 5/29 -

7/1 0)

Alexandrium sp . 96.3 μg/1 00 g, mussels (Mum ford

Cov e); 18 7.9 μg /100 g , muss els(Palmer Cove)
Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

as to Lee County Dead fish (insh ore an d offs hore) from

Pin ellas to Lee County; res pirato ryirr itatio n from Pin ellas to Lee County;water dis coloration f rom Manatee toLee County

Shellfish bans: 9/4-1 /17(Lo ngboat Key, Saraso taCou nty); 9/8-1/17 (Lo werTam pa Bay , ManateeCou nty); 9/9-1/17 (LemonBay , Sarasota County) ,(Lemon Bay and Gas parillaSou nd, Ch arlotte Coun ty),(Pine Island So und an dMatlacha, Lee County) ;9/1 5-1/17 (Boca Ciega Bay ,Pin ellas County )

Gym nodiniumbreve

fro m negative to 2,10 0,000 cells/liter(co astal surface water); fr om neg ativeto 10,330 ,000 cells/liter ( offsho resur face w ater)

as to Lee County Rep orts o f diso riented and sick s ea

bir ds (particularly cormorants); someres pirato ry irr itatio n on S iesta andLid o beaches (3 /3-3/4 ); rep orts o f dead bir ds and a few fish off Clearwater(2/9); reports of dead bird s anddolphin at Egm ont Key (2/9 )

Shellfish harvesting ban(2/26-3/2 3) in Longbo atKey (Sarasota County) 

Gym nodiniumbreve

up to 233 ,000 cells/liter ( coastal surf acewater); u p to 1 63,000 cells /liter (of fshore, 3-5 miles out)

ota to Collier

y

Dead fish (offs hore about 2 0 miles offLee County and "massive fis h kill"rep orted by SEA MAP cr uise b etween 10- 20 nau tical miles offsho re fro mVen ice to San ibel; respir atory irritationand dead fish o n Gas parilla Island

Shellfish ban ( 10/26- 11/22) in Lemon Bay an dGas parilla Soun d

Gym nodiniumbreve

up to 6,3 00 cells/liter (co astal surface)

as and Manatee

es

Dead fish (offs hore and beach);Gulfport beach closed on 4/9;res pirato ry and eye irritation

Shellfish bans (3/24 - 5/5) -Pin ellas and Manateecou nties

Gym nodiniumbreve

< 8 50,000 cells /liter (coas tal su rfacewater); < 12,70 0 cells/liter (off shoresur face); 1,000 -14,70 0 cells/liter(of fshore botto m water)
nued)

Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

as to Collier

es

Dead fish (more than 30 dif ferentspecies n oted o n some beach es);res pirato ry irr itatio n; s ome waterdis coloration in Oct and No v.

Shellfish bans: 10/4- 12/20(Pin ellas county ); 10/3-12/9 (Sarasota county); 10 /4-12/9 (Man atee county) ;10/11-12/9 (Charlottecou nty); 10/11- 12/20 (Leecou nty); 10/25- 12/20(Co llier county )

Gym nodiniumbreve

ran ged fr om neg ative to 970 ,000cells/liter (co astal surface water);neg ative to 3,6 30,000 cells /liter (of fshore surface water); n egativ e to197 ,000 cells/liter ( 50' depth water)

 om Pin ellas to Lee Co.) on beaches ( mostly grunts, pin fish and gro uper) and 1/4 to 8 miles offsh ore (catfish , flou nder, hog fish, eels, grouper, pin fish, grunts ,

s h, silver tr out, batfish, and other baitfish) .

S arasota and Manatee Co. beaches.
Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

y to Spru ce Head PSP in sh ellfis h (Mytilus edulis, Mya 

arenaria, Ostrea ed ulis, Spisulasolidissima, Mod iolus mod iolus,Eus pira her os)

Aff ected areas closed to th ehar vest o f specific s pecies 

Alexandriumtam arense

<40 -233 μ g/100g (Mytilus); <40-42 μg

g/1 00g (Mya ); <40-66 μg /10 0g(Spisula); <40 μg (Ostrea); <40-52 

μg/100g; (Mod iolus); 96 & 1 75 μg/100g(Eus pira)

haven to

insto n (Can adian

er)

PSP in sh ellfis h (Mytilus edulis, Mya arenaria, Mod iolus mod iolus, Arcticaislandica , Pla copecten mag ellanicus,Eus pira her os)

Aff ected areas closed to th ehar vest o f specific s pecies 

Alexandriumtam arense

<40 -674 μ g /100 g (Mytilus); <40-66 9

μg /100g (Mya ); <40-13 4 μg /100g

(Mod iolus); 594-11 55 μg /100g(Pla copecten); <40-12 42 μg/100g(Arctica); <40 & 97μg ( Eus pira)

y to Spru ce Head PSP in sh ellfis h Aff ected areas closed for

har vest

Alexandriumtam arense

<40 -445 μ g /100 g

port to Canadian 

r

PSP in sh ellfis h Aff ected areas closed for

har vest

Alexandriumtam arense

<40 -1927 μg /10 0g

er Harbor to

dian Border 

PSP in sh ellfis h (Mytilus edulis, Mya arenaria, Mod iolus mod iolus, Arcticaislandica , Pla copecten mag ellanicus)

Aff ected areas closed to th ehar vest o f specific s pecies 

Alexandriumtam arense

<40 -3060 μg /10 0g (Mytilus); <40-11 45

μg /100g (Mya ); <40-12 77μg /100g(Mod iolus); <40-24 78 μg 100g(Pla copecten); <40-58 7 μg /100g(Arctica)

y to Spru ce Head PSP in sh ellfis h (Mytilus edulis, Mya 

arenaria, Ostrea ed ulis, Spisulasolidissm a, Mod iolus mod iolus,Lun atia her os)

Aff ected areas closed to th ehar vest o f specific s pecies 

Alexandriumtam arense

<40 -1470 μg /10 0g (Mytilus); <40-59 5

μg/100g ( Mya ); <40-85 8 μg /100g(Spisula); <40-46 μg /1 00g (Ostrea);

<40 -107 μ g /100 g (Mod iolus); 298-114 0 μg /100g ( Lun atia)

y to Spru ce Head;

er Harbor to

insto n (Can adian

er)

PSP in sh ellfis h (Mytilus edulis, Mya arenaria, Ostrea ed ulis, Spisulasolidissm a, Arctica islandica ,Pla copecten mag ellanicus)

Aff ected areas closed to th ehar vest o f specific s pecies 

Alexandriumtam arense

Tox icity ranged from <58 - 7217 μ g/10 0g

y to Pem aquid;

klin to Gou ldsbor o;

ott to Rob binsto n

PSP in sh ellfis h Aff ected areas closed to th e

har vest o f shellfish

Alexandriumtam arense

Tox icity ranged from <58 - 1,400 μg/10 0g
e d)

Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

cook Bay an d

ort

Tox icity (dom oic acid) in bluemus sels ( Mytilus edulis)

Clo sure o f area to th ehar vestin g of all shellfish 

Pseudo-nitzschia sp.

Dom oic acid con centrations of 5 - 20ppb .

oit Bay,

wick 

Mor talities of marine inver tebrates(sh ellfis h and marine worms );coloratio n of w ater - brown 

Clo sure o f area to th ehar vestin g of all shellfish 

Gym nodiniumnag asakiense(Gyr odiniu maur eolum)

1,8 00,000 cells /liter ; the total cell countsare unlik ely to cause anoxia

Tox icity in shellfish Clo sure o f shellfish beds - 

Mya arenaria, Mytilis edulisand other species

Alexandriumfun dyense

> 8 0μg/10 0g; 1,000 - 5,000 cells/liter

Porp oise to York ,

e

PSP detected in shellfish Quarantin e Alexandrium

tam arense

<58 -4215 μg/100 g
TTS

Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

ges Bank Sur f clam s (Spisula solidissima)

con tinued to retain p aralytic shellfish tox ins th at wer e accu mulated duringMay and J une 19 90.

Clo sure o f Geor ges Bank tohar vest o f certain molluscan shellfish was continu edthr oughou t 1992 

Alexandriumfun dyense an d/or A.tam arense

100 -200 μ g/100g (whole anim als); 200-500 μg/10 0g (mu scular tissu es)

ern Coast Tox icity in sof t-shell clam s Shellfish Closu re Alexandrium

fun dyense; A.tam arense

120 μg/100 g, PSP 

ges Bank Tox icity in sur f clam s Shellfish Closu re (scallop

fis hery w as not affected)

Alexandriumfun dyense; A.tam arense

sev eral h undred μg/10 0g, PS P

ges Bank Filter-feeding shellf ish (s urf clams,

ocean quahogs, blue m ussels , andscallops) accum ulated PSP toxins; 8fis hermen were poison ed (2 seriou slyand 1 nearly died)

Shellfish ing banned; the seascallop f ishery remainedopen because th e addu ctormus cle remains toxin- freeor nearly so

Alexandriumtam arense

 Sho re and South 

 of Boston ;

ern extent is Cape

Canal

Tox icity in shellfish Mytilis edulis, Mya 

arenaria, and oth er species

clo sed to shellfish ing fr omlate May to mid -Aug;Spisula solidissima closedto shellfish ing year-rou nddue to retentio n of thetox ins at Georg es Ban k

Alexandriumfun dyense; A.tam arense

200 -300 μ g/100g ; 500- 2500 cells/liter

 and South Shores

ston ; Southern

 is the east

nce to Cap e Cod

; Georges Bank in

89

Tox icity in shellfish (Mya arenaria,Mytilus edulis, and oth ers); highes tever reco rded s hellfish tox icity in MA;tox in detected in sur f clam s andscallop v iscera on Georges Bank; nokno wn hum an or marine mammalillnesses 

Nearshore shellfish b edclo sures (>80 μ g toxin/100g shellfish ) for severalspecies; offsho re sur f clam (Georges Bank) industryclo sed by NMFS

Alexandriumfun dyense

200 -5,000 cells /liter 
TTS (Continued)

Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

 and South Shores

ston ; southern

 is the east

nce to Cap e Cod

, Nantucket

s; isolated

eaks in Eas tham

rleans on Cape

Tox icity in shellfish ; toxin detected inoff shore mussels on N antuck et Sho als

Clo sure o f shellfish beds - Mya arenaria, Mytilisedu lis an d other species

Alexandriumfun dyense

> 8 0μg/10 0g; 1,000 - 5,000 cells/liter

achus etts and Cap e

Bays

mor tality of 15 humpb ack an d 2 min kewhales

Pub lic health advisor yiss ued, w arning consu mersabo ut con suming mackerel,esp ecially the viscer a.

Sax itoxin identified in the viscera and liv er of macker el; 40 -600 m g/100g ofliv er or viscer a, or about 20 μg/kg fis h.

scallop fishery (Georg es Ban k) has not b een af fected by th e PSP toxicity pro blem b ecause this fisher y utilizes o nly th e addu ctor m uscle, which remains

n o cean environ ment, 100-20 0 miles from the n earest land (Cape Cod).
RE

Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

 NH coast Tox icity in shellfish (Mya arenaria,

Mytilus edulis, an d others); n o know nhum an or marine mammal illn esses

Nearshore shellfish b edclo sures (>80μg toxin /100gshellfish ) for several species

 NH coast Tox icity in shellfish Clo sure o f shellfish beds - 

Mya arenaria, Mytilis edulisand other species

Alexandriumfun dyense

> 8 0 μg/1 00g; 1 ,000 - 5,000 cells /liter 
Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

n Bay sou th sho re

 Cliffwood Beach 

Keansburg ,

ally dens e in

ort H arbor) ; also 

ding in lesser

ity from Sandy

Bay along NJ

o about Long

h, w ith highest

y at Sea Bright.

Kill of m arine fauna in vicinity ofCliffwood Beach ; roug hly 15 ,000dead fin fish and shellfish wereobs erved over a total stretch of about200 0 yard s at Cliffwood Beach ;sev eral m ore dead fis h and crabs wereseen in Key port H arbor about thesam e time (7/21 -22)

Increased surveillance byNJD EP and USEPA 

Katodiniu mrotundatu m(do minant);Olisthodiscus luteusand Eug lena/

Eutreptia spp .(su bdomin ant);Chr oomona s spp .

< 1 04 cells/ml (Katodiniu m

rotundatu m); < 5x10 3 cells/ml

(Olisthodiscus luteus, Eug lena/Eutreptia spp ); oth er species at arou nd103 /m l

 Hoo k Bay Bro wn water; Flocculent dep osits Increase surveillance Diatoms:

Tha lassio siranor denskioldii,Cha etocer ossociale,Lep tocylindrusmin imum,Cyclotella sp .;Chlorophy ll a

5x1 04 cells/ml (Diatoms); > 50 m g/liter

(Ch loroph yll a)

 Riv er Water dis coloration Sur veillance Pro rocentrum

red fieldi, P.min imum,Gyr odiniu m sp .,Eug lena sp .,Katodiniu mrotundatu m,Chr oomuna s sp .,Tha lassir osira sp .

2x1 04 cells/ml

 Hoo k Bay Red water Con tinued monitoring Pro rocentrum

min imum

2.5 x104 cells/ml
C ontinued)

Location/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

gat Bay Yellow br own water (s ummer long);

Pos sible ecolog ical d amage in eelgrassmor tality 

Ong oing s urveillance Nan nochlo ris

ato mus;Chlorophy ll a

106 cells/ml (Nan nochlo ris ato mus); >

22 mg/l ( Chloro phyll a)

gat Bay Yellowish -brown water (summ er

lon g); mats of dead eelgras s on s hores

On- going surveillance Chlorophy te

Nan nochlo risato mys;Chlorophy ll a

> 1 06 cells/ml durin g bloo m peak s in

late Jul and late Aug ; Chlo rophyll a

ran ged 15 .71-24 .26 μg /liter for J un 12 -Sep 12

n/S andy H ook

most inten se and 

ten t in the estuary)

Bro wn water dis coloration through out;res ultant brown flocculent materialand foam deposits on area s hores

Con tinued surveillance;intensive survey of theestuaries area

(Diatoms) Skeletonemacos tatum,Tha lassio sira spp ,Cylindrothecaclo steriu m,Hem iaulus sin ensis,Cha etocer os spp 

> 1 05 cells/ml

gat Bay Bro wnish water discoloratio n; lar ge

mats of d ead eelgrass on sh orescoinciden t with brown water ; (spo rtfis h catches pr obably affected)

Con tinued routinesur veillance

(coccoidpicoplank ton)Nan nochlo risato mus

> 1 06 cells/ml

n Bay - S andy

Bay (south ern

red dish-b rown w ater; fauna kills June22- 28; Au g 2, S andy H ook Bay southsho re. The fau na kill in J une in cluded mor talities of fin fish, especiallynor thern pip efish, scup, north ern searob in, smallmouth flou nder, andsum mer flounder . Meg ainver tebrateskilled in cluded shore shrim p, san dshr imp, b lue cr ab, an d lady crab. Theear ly Aug . kill also involv ed fin fishand shellfish, primar ily dem ersalspecies ( flound er, cr abs, etc.).

Increased surveillance Dom inant species

(5,000-25 ,000cells/ml) :Olisthodiscusluteus, Katodiniu mrotundatu m, and

Eutreptia lan owii.Sub domin antspecies ( 1,000- 5,0 00 cells/ml) :Pro crocen trummin imum, and P.

triestinu m

Kills attributed to localized hyp oxia,con tributed by wind and tid e. (D .O.lev els as low as 2.2 mg/liter)
C ontinued)

n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

and entir e

w Jersey,

o a few

Bro wn flo cculen t material, or foam, onmuch of N J shor e

Increased surveillance Cer atulin a

pelagica; Skeletonemacos tatum (in someplaces)

ran ged 1,000-20 ,000 cells/m l, butusu ally 1 ,000-1 0,000 cells/ml(Cer atulin a pelagica); 1,000- 10,000 cells/ml (Skeletonema cos tatum);

Chlorophy ll ran ged 3- 10 μg/l; D.O ., atbottom, < 3.0 ppm (Long Beach ), and 1.5 -4.8 ppm (Seas ide Heights) 

y Bro wnish water discoloratio n; lar ge

mats of d ead eel gras s on s hores

Increased surveillance Nan nochlo ris

ato mus (d ominan t);Aur eococcusano phagefferens (<7.5 %)

100 ,000-1 ,000,0 00 cells/ml (totalpicoplank ton); 12 μg/liter (Chlor ophyllNor th end ); 24 μg/liter (Ch loroph yllSou th end )

occu rred o nly occasion ally ( usually localized) at Sh ark River, a relatively small estuar y. Occasion al red tides in th e adjacent coastal water s have

act (i.e., complaints of res pirato ry irr itatio n by b athers ) -- o ccurrences w ere in 1968,1972, and 19 80-82.

d ents w ere ex cluded .
n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

Bay ; the

resent

he bay with

entration s

th e central

ween

d Patchogue

Aes thetic (brow n water); reducedtransparency po ssibly affecting g rowthof rooted vegetation in deeper ar eas;app ears to affect gro wth an drep roduction (larval surviv al) of shellfish species (pr imarily hard clam,Mer cenaria mer cenaria, in GreatSou th Bay )

increased frequ ency o fmon itorin g activities 

Aur eococcusano phagefferens 

ran ged fr om >10 3 to >106 cells/ml; 5.4- 

10.7 mg/liter ( dissolved ox ygen)

d

Bays ;

oncentrated

or iches

n

Bay and

nn ecting 

 Quantuck

Aes thetic (brow n water); reducedtransparency po ssibly affecting g rowthof rooted vegetation in deeper ar eas;app ears to affect gro wth an drep roduction (larval surviv al) of shellfish species (pr imarily hard clam,Mer cenaria mer cenaria, in GreatSou th Bay )

increased frequ ency o fmon itorin g activities 

Aur eococcusano phagefferens 

7.2 -11.7 mg/liter (dissolved oxyg en)

Bay and

bor, Shelter

 eastern end

ic Bay

Aes thetic (brow n water); reducedtransparency po ssibly affecting g rowthof rooted vegetation in deeper ar eas;app ears to affect gro wth an drep roduction (larval surviv al) of shellfish species (pr imarily hard clam,Mer cenaria mer cenaria, in GreatSou th Bay )

Con tinue weekly mon itorin g prog ram;increase parametersinv estigated an d fund ing of res earch activities

Aur eococcusano phagefferens 

up to 106 cells/ml (West Neck Bay); up

to 8.5x10 5 cells/ml (Coecles H arbor) ;

6.5 -8.4 m g/l (d issolv ed oxy gen)

 sys tem Deleterio us eff ects o n various sh ellfis h

species; water discoloratio n; red ucedtransparency

Con tinue weekly mon itorin g

Aur eococcusano phagefferens 

106 cells/ml

Bay, Shelter

Water dis coloration and red ucedtransparency

Con tinue weekly mon itorin g

Aur eococcusano phagefferens 

5.6 x105 cells/ml (Jul) ; 1.8x 104 cells/ml

(Oct)
ntinued)

n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

nty n orth

s

Extensive green disco lored water;gen erated numer ous co mplain ts; so meoys ter po st-set death s noted by localcom mercial oyster com pany

Mon itor; press releas e Eutreptiella sp . up to 17 mill. cells/liter

nty n orth

s; especially

Har bor an d

Harbo r,

ay

Num erous complaints o f discolored water and "sewage/slu dge" J ubileetyp e fish kill affecting pr imarily baby flo under in Cold Spring har bor - Jul12th; dead Mytilus edulis an d Can cer

irr oratus in Man hasset Bay - Jul 1 0-13th

Sam ple; p ress r elease Pro rocentrum

triestinu m;Eutreptiella sp.;SkeletonemaRhiosolen iafra giliss ima;Cha etocer osper pusillus;Sin ophysisacu minata 

up to 50 mill. cells/liter

d

Bays ; the

mainly

 in eastern

y an d

nnecock Bay

Primarily aesth etic effects ; waterdis coloration and red ucedtransparency

Increase monito ringfrequency 

Aur eococcusano phagefferens 

104 to 9.6x1 05 cells/ml at eastern

Mor iches Bay an d western ShinnecockBay ; 103 to 105 cells/ml at other ar eas

nty, Near

sland

within the

 har bors

Hem pstead 

Dis tinct brown water discoloratio n;one possible illness episod e later in f all(2 person s with DSP like sy mptoms )fro m local clam s

Increased surveillance andsam pling toxicity with"UBE" tes t

Din ophysisacu minata 

700 ,000 cells/l (high est co unt); UBEtes t resu lts, > .5 MU (2 stations )

Bay and

 Sys tem,

Iso lated blooms peaked in m id Jun e,then dwin dled to undetected levels byend of su mmer

Suf folk County monito ringpro gram w as car ried o ut

Aur eococcusano phagefferens 

< 5 00,000 /ml max cell number in G reatSou th Bay ; up to 1,00 0,000/ml inPeconic s ystem

 NY; G reat

ng I sland

Gro wth su ppress ion in M. mer cenaria;delay of spawning in M. mer cenariauntil cou nt/ml decreased to muchlow er lev els (< 350,0 00/ml) 

Raw water upwellingsys tems m oved to L.I.Sou nd to avoidAur eococcus (" Wait it out" )

Aur eococcusano phagefferens 
ntinued)

n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

 and Great

Long Islan d

Mor tality of ju venile and larvalscallops; water color ation - brow n;eelgrass mortality

Re- seedin g of juvenilescallops attemp ted;uns uccess ful du e tomor tality 

Aur eococcusano phagefferens 

< 1 ,000,0 00 cells/ml (Aur eococcusano phagefferens ); < 25-3 0 μg/liter(ch loroph yll); normal oxygen cond ition

o ration events were not entered .

 widespread blo om in Nassau County north shor e harb ors in mid-J uly, 1 987.

P SP wer e not entered.
INA

n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

am lico

y & Core

tal waters 

gton, NC

small fis h kills / sh ellfis h kills(lo calized)

non e "Ph antom" 

din oflagellate

er, Taylor 

e Riv er

Mas sive k ills o f fin fish & shellfish;sep arate fisher ies an d public healtheff ects

Sam pling protocol to detectand verif y pres ence o f thetox ic din oflagellate

new species withingen us Alexandrium

shelf of NC

est of Cap e

lud ing

nlets ins ide

nks and

rier Islands

Neu rotoxic shellfish poison ing (N SP),48 illnes ses; r espiratory irritation in hum ans; f ish an d scallop mor talities(mo re than 50%) ; water colo ration -vis ible

Shellfish quarantine forwaters to south of CapeHatteras

Gym nodiniumbreve

< 2 0,000,000 cells/liter

ave associated the new species (n ow kno wn as Pfiesteria pis cicida ) w ith ap proxim ately 25% of the f ish kills wh ich have occurred in the Pam lico

f fish kills in these estuar ies have been asso ciated with "sudden death" of many f ish sp ecies and shellfish which exhib ited neu rotoxic symp toms.

ls/liter Ptychodis cus brevis (b elow the shellfish bed closure level of 5,000 cells/liter) w as not enter ed.

ATIO N]

8 red tide, the eco nomic losses to th e coas tal co mmunity were conservativ ely es timated at $ 25 million ( Tester et al. 19 88).
n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

(a distance

ately 36

8' N,

o 44o27' N,

Dead fish (mack erel) covering a largearea; n o bird s were eatin g the dead f ishand there were no oth er species o fdead fish .

Not confirmed,pos siblyAlexandriumcatenella 

Dead mack erel ( Oct): 187-20 1 μg/1 00g(viscera) , <38- 41 μg/100g ( meat). Livemackerel (Nov): 97-11 6 μg/7 0g(viscera) , <37 μg/100 g (meat). Liverockfish (Nov): <30 μ g/80g (viscera),<36 μg/10 0g (meat)

ort to th e

ver (ca.

eg rees N .)

Clo sure o f razo r clam commercial andrecreatio nal harvest caused sever eeco nomic problems for at least 2bus inesses; mus sel harvest also closed,but most is don e south of the clo surearea. On e repo rt of PSP in Dun geness crab viscera causing a health war ningto people who eat crab viscera,add itional testing to ensur e safe crabfor expor t. On e repo rt of deadmackerel containing P SP off the coast.

Har vest closure for allshellfish north of Reedsportas of 12 Aug; o ysters andbay clams lot s ampled inSep & Oct; shellfish otherthan razo r clam s andmus sels r eleased from clo sure in early Nov; razor clams and musselsrem ained closed throu gh theend of 19 92

tho ught to beAlexandriumcatenella 

PSP , 88 μ g/100g in mu ssels (late Jul -ear ly Aug ); (<4 367 μg /100g) , oysters(80 μg/10 0g) an d little neck clam s (225 μg/100g) affected; razor clams (2 10μg/100g) affected in Nov.

28 human illnes ses reported in WA &OR (mild) ; razo r clam s andDun geness crabs becam e into xicatedwith dom oic acid

Clo sure o f comm ercial andrecreatio nal harvest of razorclams on WA and ORbeaches; closed commercialfis hery f or Dun geness crabs fro m northern Cal. to nor thern Wash. for a month

Pseudo-nitzschia aus tralis 

Razor clams wer e still toxic in m idMar ch '92 with dom oic acid lev els of 30- 60 ppm (regu latory closu re lev el is20 ppm )

t Elevated PSP levels in Oct and No v;

exceeding 80 μg /100g in Nov 

Clo sure o f portions o f thecen tral O regon coast from15- 28 Nov for shellfish ing

Alexandriumcatenella 

PSP ; 89.4 μg/10 0g (11 /14); 113μg/100g ( 11/19) 

ert began in 9/25/91 on the gener al beaches in muss els, p eaking at 15 0 μg/100g and declining to < 50 μg/100g b y 10/3 0/91.
n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

nel running

Mad re near

Fis h kills and limited repo rts of aer osol ( respir atory irritation)

Shellfish harvesting banssou th of Port Mansfield(No v 1990 - Mar 1, 19 91,still con tinuin g at the tim eof this r eport) 

Gym nodiniumbreve

up to 300 ,000 cells/liter

d along much of Tex as coast in 1986.
n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

 o f

State and

ries of

 and Grays 

Shellfish toxicity (P SP) - highes tlev els measured in razor clams in thesur f zone. Low er lev els in commercialoys ters and clams within co astalestuaries 

Pos tponem ent of recreatio nal razor clamfis hery o pening sched uledfor Oct 9 until Nov 1 3,199 2. Closure ofcom mercial oyster bed s inWillapa Bay and Grays Har bor. Minor productrecall.

Alexandriumcatenella 

Razor clams: 72 0 μg/1 00g (m eat), 3500μg/100g ( viscer a). 1 97 μg/100g inPacific o ysters in Gr ays Harbor estuary .

arin a,

outhern

Mor ning: 90g fish (Des chutes stock fall chinook s almon) off f eed.Afternoon : fish rapid ly dying; becamepale in color, gills were b right orangewith tips of gill filaments bent;kid neys w ere so ft and blood y. Th erewer e no o ther p athogens present.

Fis h were released fr om netpen s; pro bably fewsur vived.

Unk nown, but a 28- 30 μm diameter,pig mented ,Gym nodinium-likedin oflagellate waspresent. Also,Pseudo-nitzschia pun gens f. pun gens.

28 human illnes ses reported in WA &

OR (mild) ; razo r clam s andDun geness crabs becam e into xicatedwith dom oic acid

Clo sure o f comm ercial andrecreatio nal harvest of razorclams on WA and ORbeaches; Closed com mercial fish ery fo rDun geness crabs fromnor thern Cal. to northernWas h. for a mon th

Pseudo-nitzschia aus tralis 

Razor clams wer e still toxic in m idMar ch '92 with dom oic acid lev els of 30- 60 ppm (regu latory closu re lev el is20 ppm )

t S ound,

Bellingham 

ngeles

Tow nsend

n H ood

Killed Atlantic salmo n in n et pen s(central Puget Sound) ; larg e fish (br ood stock) w ere af fected first; also killed br ood stock of White River spr ing chinook s almon in net pens

Fis h grow ers harvested fish ;two growers tow ed theirpen s to clear w ater

Heterosig maaka shiwo

50,000 - 4,000,000 cells/liter (at pensites); > 12,00 0,000 cells/liter detectedin Port A ngeles harbo r
(Continued)

n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

Hig h toxin in s hellfish Lib erty Bay clo sed to all

com mercial and sporthar vestin g of s hellfish;recall of commerciallyhar vested oysters fro m 17states (n o illn esses reported)

Alexandriumcatenellu m

tox in lev els were 226 -358 μ g/100g 

 o f

 Van couver 

),

San Juan

)

Hig h concentration of algal cells ; nohar mful effects (fish growers wor riedabo ut eff ect on net-p en fis h)

Gon yaulaxspinifera 

1.5 -4.5 m ill cells/liter in patch es;for med cy sts

Hig h cell concentration; no effects

only because fish gro wers in the areadid not h ave fish in the water

Cha etocer oscon cavico rnis

40,000 - 74,000 cells /liter , and up to 10mill cells/liter

ake, Pierce

As of Jan 10, 1 990, 5 dead cats, 1 illcat, 1 dead dog , 5 ill dogs and 3 deadwaterfowl were suspected to havebeen due to the algae (firs t repo rtedanimal illness) ; a few necropsys havebeen perf ormed, but w ere in conclu sive

Med ia notified; fact sheets dis tributed to residentsaro und th e lake; publicaccess sites po sted w ithwar ning s igns

Ana baena flo saqu ae Anatoxin- A

nd and Po rt

rthern Pug et

Mas sive k ills o f Atlantic s almon in netpen s; als o chinook s almon andrainbow trout; mos t smaller fishsur vived. Larg er fis h died first,esp ecially broo d stock.

Rap id har vest o f dead andmor ibund fish; stoppedfeeding and oth er activityaro und th e pens ; PortAng eles h ad mor e warn ingand placed tarp s arou nd thepen s to cut dow n watercir culation and had littlelos s.

Heterosig maaka shiwo (Had a)Had a

Cells gen erally concentrated in u pper 2 m o f water.
(Continued)

n/Area Eff ects Man agemen t Decisions Cau sative Species Tox in/Tox icity/Cell C oncent ration 

y, Fid algo

Hig h PSP detected Com mercial shellfish

pro duct r ecalled; of 150pou nds, all but 7 pou ndswas recov ered anddes troyed ; clos ure fo rcom mercial shellfish ing

Alexandriumcatenella 

804 μg/10 0g (Washington sam ple); 470μg/100g ( Califo rnia, product receiverstate, sample)

ug et Sou nd 5 confirm ed illnesses from

con sumption of commer cial s hucked oys ters; no recreatio nal illnessesrep orted

Imm ediate closu re ofrecreatio nal an d comm ercialhar vestin g, reo pened Oct 6;recalled 2 week s prod uction - Min terbro ok Oys ter Co .

Alexandriumcatenella 

up to 2,4 00 μg/100g ( PSP)

nd mor tality of at least 250,0 00 Atlantic

and Pacif ic salmon

Cha etocer oscon cavico rnis

ATIO N]

 P SP event, th e comm ercial shellfish industr y estimated the lo ss of "$1million" due to recall and closu res.

 f ish kill, th e dead fish were estimated to be wor th $4- 5 million (Hor ner et al. 19 91).

fish kill, the losses to three f arms and fou r separate n et-pen systems: 2,000,00 0 lbs. or ab out 95 % of the total cro p.

e loss es wer e over $0.5 millio n (Ren sel et al. 19 90).
89

APPENDIX B

List of Local Experts Contacted by Letters
90

GENERAL

Sandra E. Shumway

Natural Science Division

Southampton College, LIU

Southampton, NY 11968

Sshumway@southampton.liunet.edu

ALASKA

Ronald K. Dearborn

Alaska Sea Grant College Program

University of Alaska

138 Irving II

Fairbanks, AK 99775-5040

Fnrk@uaf.edu

Michael J. Ostasz

Shellfish Program Coordinator

Department of Environmental

Conservation

3601 C Street, Suite 1324

Anchorage, AK 99503

Mostasz@envircon.state.ak.us

Craig Wiese

Sea Grant Program

University of Alaska, Fairbanks

2221 E. Northern Lights Blvd, #110

Anchorage, AK 99508

CALIFORNIA

James A. Fawcett

University of Southern California Sea

Grant

Hancock Institute for Marine Studies

University Park

Los Angeles, CA 90089-1231

James J. Sullivan

California Sea Grant College Program

Univ. of California - San Diego A-032

La Jolla, CA 92093

Kenneth Hansgen

Department of Health Services, EHSS

Sacramento Office

714 P Street, Rm. 616

Sacramento, CA 95814

Richard E. Danielson

Department of Health Services

Sanitation and Radiation Laboratory

2151 Berkeley Way

Berkeley, CA 94704

Greg Langlois

Department of Health Services

2151 Berkeley Way, Rm. 118

Berkeley, CA 94704

Sue Yoder

University of Southern California

University Park

Los Angeles, CA 90089-1231
91

CONNECTICUT

Edward C. Monahan

Connecticut Sea Grant College Program

University of Connecticut

Avery Point

Groton, CT 06340

Sgoadm01@unconnvm.unconn.edu

Malcolm Shute

Connecticut Department of Agriculture

Aquaculture Division

P.O. Box 97

Rogers Avenue

Millford, CT 06460

Dept.agric@snet.net

Subject Line: Attention Malcolm

Shute

James Citak

Aquaculture Division

Department of Agriculture

State of Connecticut

P.O. Box 97

Milford, CT 06460

Dept.agric@snet.net

Subject Line: Attention James Citak

John Volk, Director

Department of Agriculture

State of Connecticut

P.O. Box 97

Milford, CT 06460

Dept.agric@snet.net

Subject Line: Attention John Volk

DELAWARE

Carolyn Thoroughgood

Delaware Sea Grant College Program

Graduate College of Marine Studies

Robinson Hall

Newark, DE 19716

C.Thoroughgood@mvs.udel.edu

FLORIDA

James C. Cato

Florida Sea Grant College Program

Building 803

University of Florida

Gainesville, FL 32611

Jcc@gnv.ifas.ufl.edu

Beverly Roberts

Marine Research Laboratory

Florida Dept. of Natural Resources

100 Eighth Ave., SE

St. Petersburg, FL 33701-5095

Bev.Roberts@dep.state.fl.us

GEORGIA

Mac Rawson

Georgia Sea Grant College Program

University of Georgia

Ecology Building

Athens, GA 30602

Mrawson@arches.uga.edu

Brad Williams

Shellfish Program Leader

Georgia Department of Natural

Resources

1 Conservation Way

Brunswick, GA 31523-8600
92

HAWAII

Jack R. Davidson

Hawaii Sea Grant College Program

University of Hawaii

1000 Pope Road, Rm. 223

Honolulu, HI 96822

Yoshitsugi Hokama

Department of Pathology

Room T-512

University of Hawaii

1960 East-West Road

Honolulu, HI 96822

LOUISIANA

Jack R. Van Lopik

Louisiana Sea Grant College Program

128 Wetland Resources

Louisiana State University

Baton Rouge, LA 70803-7507

Ronald Becker

Louisiana Sea Grant College Program

Louisiana State University

Baton Rouge, LA 70803-7507

Rbecker@lsu.edu

MAINE

Robert E. Wall

Maine/N.H. Sea Grant College Program

University of Maine

14 Coburn Hall

Orono, ME 04469-0114

Sally Sherman-Caswell

Department of Marine Resources

McKown Point Rd.

West Boothbay Harbor, ME 04575

Sally.Sherman@state.me.us

Robert Lewis

Dept. of Marine Resources

State House Station 21

Augusta, ME 04333-0021

Laurie Bean

Dept. of Marine Resources

Bureau of Marine Science

West Boothbay Harbor, ME 04575

Laurie.Bean@state.me.us

John W. Hurst, Chairman

Fisheries and Health Science Division

Department of Marine Resources

West Boothbay Harbor, ME 04575

John.Hurst@state.me.us

MARYLAND

Chirstopher F. D'Elia

Maryland Sea Grant College Program

University of Maryland

0112 Skinner Hall

College Park, MD 20742

Delia@cbl.umces.edu
93

MASSACHUSETTS

Chryssostomos Chryssostomidis

MIT Sea Grant College Program

Massachusetts Institute of Technology

Bldg. E38, Rm. 330

77 Massachusetts Ave.

Cambridge, MA 02139

Chrys@deslab.mit.edu

E. Eric Adams

Department of Civil Engineering

Bldg. 48-325

MIT

Cambridge, MA 02139

Eeadams@mit.edu

Michael Hickey

Massachusetts Division of Marine

Fisheries

18 Route 6A

Sandwich, MA 02563

Paul DiPietro

MDC

6th Floor

20 Somerset Street

Boston, MA 02108

Alan White

Department of Marine Safety and

Environmental Protection

Massachusetts Maritime Academy

101 Academy Drive

Buzzards Bay, MA 02532

Awhite@mma.mass.edu

Dave Whittaker

Division of Marine Fisheries

18 Route 6A

Sandwich, MA 02563

David.Whittaker@state.ma.us

MISSISSIPPI

James I. Jones

Mississippi/Alabama Sea Grant Consortium

P.O. Box 7000

703 East Beach Drive

Ocean Springs, MS 39564-7000

NEW HAMPSHIRE

Brian Doyle

New Hampshire/Maine Sea Grant

College Prog.

Marine Program Building

University of New Hampshire

Durham, NH 03824

Brian.doyle@unh.edu

John Nelson

NH Fish & Game / Region 3

225 Main Street

Durham, NH 03824-4732

Paul Raiche, Supervisor

Dept. of Health and Human Services

Division of Public Health Services

6 Hazen Drive

Concord, NH 03301-6527
94

NEW JERSEY

William G. Gordon

N.J. Marine Sciences Consortium

Sea Grant Program

Building No. 2

Fort Hancock, NJ 07732

Paul Olsen

NJ Dept. of Environmental Protection

Division of Water Resources

Geological Survey CN 029

Trenton, NJ 08625

NEW YORK

Anne McElroy

New York Sea Grant Institute

Dutchess Hall, Rm. 147

State Univ. of New York - Stony Brook

Stony Brook, NY 11794-5001

Amcelroy@notes.cc.sunysb.edu

Robert Nuzzi

Suffolk County Dept. of Health Services

Riverhead County Center

Riverhead, NY 11901

Anita Freudenthal

Nassau County Dept. of Health

240 Old Country Rd.

Mineola, NY 11501

NORTH CAROLINA

B. J. Copeland

Univ. of North Carolina Sea Grant

College

North Carolina State University

Box 8605

Raleigh, NC 27695-8605

Bjcopela@unity.ncsu.edu

JoAnn Burkholder

Department of Botany

Box 7612

North Carolina State University

Raleigh, NC 27695

Joann_burkholder@ncsu.edu

Pat Tester

NOAA/NOS

Beaufort Laboratory

Beaufort, NC 28516-9722

Pat.Tester@NOAA.gov

Mike Street

Dept. of Environmental Health and

Natural Resources

Division of Marine Fisheries

Morehead City, NC 28557-0769

Mike.Street@ncmail.net

Bob Curry

North Carolina Wildlife Resources

Commission

512 N. Salisbury Str.

Raleigh, NC 27604-1188

Karen M. Lynch

Environmental Sciences Branch

DEHNR

State of North Carolina

4401 Reedy Creek Road

Raleigh, NC 27607
95

OREGON

Robert Malouf

Oregon Sea Grant College Program

Administrative Services Building - A320

Oregon State University

Covallis, OR 07331-2131

Robert.Malouf@orst.edu

Debora Cannon

Department of Agriculture

Food & Dairy Division

635 Capitol Street NE

Salem, OR 97310

John Johnson

Dept. of Fish and Wildlife Service

2040 SE Marine Science Drive

Newport, Oregon 97365

PUERTO RICO

Manuel Hernandez-Avila

Puerto Rico Sea Grant College Program

University of Puerto Rico

Department of Marine Sciences

RUM-UPR, P.O. Box 5000

Mayaquez, PR 00708

RHODE ISLAND

Scott Nixon

Rhode Island Sea Grant College Prog.

University of Rhode Island

Marine Resources Building

Narragansett, RI 02882

Snixon@gsosun1.uri.edu

Joe Migliore

Senior Environmental Scientist

Rhode Island Dept. of Environmental

Management

Division of Water Resources

291 Promenade Street

Providence, RI 02908-5767

Jmiglior@dem.state.ri.us

 SOUTH CAROLINA

Margaret Davidson

South Carolina Sea Grant Consortium

287 Meeting St.

Charleston, SC 29401

Rick Devoe

South Carolina Sea Grant consortium

287 Meeting Str.

Charleston, SC 29401

Devoemr@musc.edu
96

 TEXAS

Thomas J. Bright

Texas Sea Grant College Program

1716 Briarcrest Drive

Suite 702

Bryan, TX 77802

Richard Thompson, Director

Division of Shellfish Sanitation Control

Texas Department of Health

1100 West 49th Street

Austin, TX 78756

Eleanor Cox

Department of Biology

Texas A&M University

College Station, TX 77843

e-cox@tamu.edu

Terry E. Whitledge

Marine Science Institute

University of Texas - Austin

P.O. Box 1267

Port Aransas, TX 78373-1267

Kirk Wiles

Texas Dept. of Health

1100 W. 49th Street

Austin, TX 78753

Ed Buskey

Marine Science Institute

0University of Texas, Austin

Port Aransas, TX 78373

Buskey@utmsi.utexas.edu

VIRGINIA

William L. Rickards

Virginia Sea Grant College Program

University of Virginia

Madison House - 170 Rugby Road

Charlottesville, VA 22903

Rickards@virginia.edu

WASHINGTON

Louis S. Echols

Washington Sea Grant College Program

University of Washington

3716 Brooklyn Ave., N.E.

Seattle, WA 98105-6716

Echols@u.washington.edu

Mary McCallum

Washington State Dept. of Health

Shellfish Office, Mail Stop LD-11

Olympia, WA 98504

Jack Rensel

Rensel Associates

2412 North 77th Street

Seattle, WA 98103

Jackrensel@email.msn.com

Doug Simons

Dept. of Fish and Wildlife

48 Devonshire Rd.

Montesano, WA 98563

Simondds@dfw.wagov
97

CANADA

Ewen Todd

Health Protection Branch

Health and Welfare Canada

Sir Frederick G. Banting Research Centre

Tunney's Pasture, Ottawa

Ontario K1A 0L2 Canada