Lake Whatcom Residential and Angler Fish Consumption Survey

Data Report

Lake Whatcom Residential and

Angler Fish Consumption Survey

DOH 334-288 Ap

ril 2001

Washington State Department o

f Health

PO Box 47825

Olympia, WA 98504-7825

1-877-485-7316

www.doh.wa.gov/fish

For people with disabilities, this document is available on request in other formats.

To submit a request, please call 1-800-525-0127 (TDD/TTY call 711).

Acknowledgements

We wish to thank everyone who supported and participated in the organization, design, and conduct of this

study. A special thank you is extended to the Whatcom County Health and Human Services Department

for providing staff and helping to organize this study and Lynn Robbins of Western Washington University

who provided comments and support. This study could not have been completed without the field

assistance of Bernadette Delish, Colin Dietrich, Mary Ann Hollerbeck, Brendan Madden, and Kelsey

Rydland; students at Western Washington University. Finally, we wish to acknowledge the Washington

State Department of Ecology and the Department of Fish and Wildlife, who provided supporting data and

project encouragement.

Contents

1 Executive Summary

3 Abstract

4 Introduction

4 Background

6 Methods

10 Survey Results

18 Conclusions

20 Bibliography

Appendix

22 A - Lake Whatcom residential fish consumption survey form

27 B - Salmon fillet photo used during the survey to quantify a typical fish meal size

Figures

5 Figure 1

8 Figure 2

Lake Whatcom near Bellingham, Washington.

Lake Whatcom Fish Consumption Survey Residential Clusters and

Surveyed Boat Launches.

Tables

10 Table 1

11 Table 2

Table 3

12 Table 4

16 Table 5

16 Table 6

17 Table 7

Residential Survey Interview Summary.

Residential Respondent Demographic Characteristics.

Lake Whatcom Fishers and Fish Consumers By Residential Strata.

Residential Sample Fish Consumption by Species.

Residential Lake Whatcom Fish Consumer Population Estimates.

Lake Whatcom Fish Species Fillet Weights.

Estimated Species-specific Fish Meal Sizes For Commonly Caught and

Consumed Lake Whatcom Fish Species.

Lake Whatcom Fish Consumption Study

Executive Summary

Overview

A survey of Lake Whatcom residents and anglers was conducted between July 21 and July 24, 2000 to

gather information on their consumption of Lake Whatcom caught fish, as well as perceptions related to

fish advisories. This project was undertaken to gather exposure information for use in assessing the

human health implications associated with the consumption of mercury contaminated fish from Lake

Whatcom. A retrospective on-site study design with a four-week recall period was selected for this

survey effort. The survey study design focused on three populations: residents who lived on or near the

Lake or in developments with direct access to the lake, boat anglers accessing the lake at public boat

launch facilities, and shore anglers at public access points. This study design was devised in order to

maximize the likelihood of gathering representative Lake Whatcom fish consumption information from the

surveyed populations. Surveys were conducted through door-to-door interviews, at frequently used boat

launch facilities, and at popular shore-fishing locations. Survey efforts focused on the north end of Lake

Whatcom, since the majority of residents and potential anglers live and access this section of the lake.

Findings

Descriptive results for the three survey populations (shore anglers, boat anglers, and residents) are

summarized below (Table 1). Surveyed shore anglers primarily catch to consume smallmouth bass,

cutthroat trout, and perch, while boat anglers reported catching cutthroat trout followed by smallmouth

bass. Residential respondents catch, in order of preference, cutthroat trout, followed by smallmouth bass,

kokanee, and perch. Crayfish and pumpkinseed were also reportedly consumed by four and one

residential respondents, respectively.

Survey results pertaining to fish consumption are summarized below by population (Table 2). Results from

this survey suggest that less than two percent of the surveyed residential population had consumed any

Lake Whatcom caught fish during the four weeks prior to the survey and that the remainder of the

population would consume such fish at a rate less often than one meal per month. Fish consumption data

averaged within each of the three survey populations were not significantly different from one another

with the exception of the number of fish meals consumed per month. Shore anglers, surveyed primarily at

Bloedel Donovan Park, tend to consume Lake Whatcom caught fish more frequently than anglers from

the other populations, with nearly half of these respondents having eaten such fish at a rate of one to ten

meals (mean=2) during the previous four weeks. Across survey populations, anglers reported eating fish

from Lake Whatcom three or fewer months out of the year. Those that are catching and eating fish are

primarily the older segment of the population and primarily males. While few fish consuming households

contained children, it was reported that younger children (>8 years of age) eat Lake Whatcom caught fish

at the same frequency as the adult household members.

During the four-week recall period, survey respondents who consume Lake Whatcom fish also reported

consuming canned or fresh tuna at an average rate of one meal per week. While this survey did not

gather information on the amount of tuna consumed per meal, the fact that tuna averages 0.17 mg/kg

methylmercury (Yess, 1993), suggests that tuna consumption may be a more significant source of mercury

exposure for many local residents due to tuna consumption frequency than the consumption of Lake

Whatcom caught fish.

Pertaining to survey results dealing with fish consumption advisory perceptions, nearly 50 percent of

respondents (n=21), indicated they would continue eating fish from Lake Whatcom following health

recommendations contained in an advisory, 38 percent said they would stop eating Lake Whatcom fish

entirely, while 14 percent would continue eating fish unabated. Seventy-five percent of parents with

children indicated they would stop feeding their children fish from Lake Whatcom if an advisory were

posted.

Conclusions

The small number of anglers and the small proportion of the residential population that actually consumed

any Lake Whatcom caught fish during the four week recall period prior to the survey, limited our ability to

fully quantify fish consumption characteristics of the local population, especially for women and children.

However, these findings indicate that the majority of anglers consume fish from Lake Whatcom at a rate

of less than one meal per month and that anglers consume Lake Whatcom caught fish three or fewer

months out of the year. This study also identified the presence of a small proportion of anglers that

consume fish from Lake Whatcom on a weekly basis and in amounts, which may be sufficient to pose a

health risk due to mercury contamination. Assessment of human health concerns associated with mercury

in Lake Whatcom fish should also include consideration of canned tuna consumption due to the more

frequent consumption of tuna relative to fish caught from Lake Whatcom. While reported fish

consumption rates, based on the consumption of locally caught fish, reflect rates constrained by external

factors, estimates of consumption based on the fillet photo provide a good upper bound rate estimate for

conducting exposure analyses.

Table 1. Survey data and population demographic summary information.

Sample Survey Sex (%) Fishers Eat Fish Age Years (%)

Frame Attempts Completed % M F (%) (%) <18 18-45 46-65 66+

Shore 10 10 100 80 20 100 90 30 50 10 10

Boat 16 16 100 88 12 100 68 0 88 6 6

Residents 386 194 50 45 55 22 11 2 25 42 29

Total 394 220

Table 2. Fish consumption data summary for anglers who consume Lake Whatcom caught fish.

Sample No. Months/ No. Years Typical Fish

Population Yr Fish Eaten

(avg ±± sd)

Fish Eaten

(avg ±± sd)

Meal Size (gms)

(avg ±± sd)^

Shore (n=7) 2.5±0.6 9±9 249±68

Boat (n=10) 1.9±0.6 13±17 264±39

Residents (n=21) 2.7±1.4 19.5±16.3 225±67

^ Fish meal size based on salmon fillet photo

Abstract

A fish consumption survey was conducted by the Washington State Department of Health on Lake

Whatcom, Whatcom County, Washington between July 21 and July 24, 2000. The goal of this survey was

to gather information on the consumption of Lake Whatcom caught fish by local residents and anglers in

response to preliminary findings of elevated mercury concentrations in some fish species. Surveys of

randomly selected residential clusters, and boat and shore anglers, were conducted in person by survey

teams using a structured survey instrument. Cutthroat trout and smallmouth bass are the primary species

caught and consumed. A small proportion of residential respondents indicated they eat fish from Lake

Whatcom (≅11%), while less than two percent indicated that they had consumed any of such fish during

the four week period prior to the survey. The proportion of surveyed boat and shore anglers who

consumed any Lake Whatcom fish during the four weeks prior to the survey was six and forty percent

respectively. In general, shore anglers have the greatest intake of Lake Whatcom caught fish due to the

frequency of fish meals, although boat anglers typically consume a higher mass of locally caught fish per

meal due to the consumption of larger fish. All anglers reported consuming Lake Whatcom caught fish

three or fewer months out of the year. When fish catch is not the limiting factor, anglers typically

consume about one-half pound of fish per meal. In general, residential and boat anglers consumed tuna

four times more frequently than they did fish caught from Lake Whatcom, while shore anglers consumed

tuna and Lake Whatcom caught fish at similar frequencies. With regard to angler perceptions and

reactions to a theoretical fish advisory, most anglers indicated they would follow the recommendations of

the fish advisory.

Introduction

Recent findings by the Washington State Department of Ecology regarding mercury in fish from Lake

Whatcom raised concerns by local and state health agencies and prompted a more thorough investigation

into contamination levels and human exposure to mercury in these fish. To address questions pertaining to

human exposure to mercury in Lake Whatcom caught fish, the Washington State Department of Health,

Office of Environmental Health Assessments, in collaboration with the Whatcom County Health and

Human Services Department, conducted a survey of Lake Whatcom residents and anglers between July

21 and July 24, 2000. The purpose of this study was to gather baseline quantitative information on the

consumption of Lake Whatcom caught fish and tuna by local residents and anglers, as well as qualitative

information on their perceptions related to fish advisories in general. Fish consumption information

resulting from this study will be used in conjunction with fish tissue mercury data and information on the

toxicology of mercury to assess the human health implications associated with the consumption of mercury

contaminated fish from Lake Whatcom. This report summarizes the findings from this survey as well as

the methods used for data collection and evaluation.

Background

Lake Whatcom is located in the northwest corner of Washington State in Whatcom County at the western

edge of the Cascade range foothills (Figure 1). Lake Whatcom is a large body of water extending

approximately twelve miles from north to south and covering an area of approximately 4,836 acres. The

Lake has three distinct basins separated by glacial sills, with a maximum depth of 328 feet. With its many

bays and inlets, Lake Whatcom’s perimeter extends approximately twenty-eight miles. In addition to

providing sport fishing and recreational opportunities, Lake Whatcom is the source of drinking water for

the City of Bellingham and neighboring residents.

Human health concerns over mercury contamination of Lake Whatcom fish were initially raised due to

findings from a screening–le vel fish tissue study by the Washington State Department of Ecology

(Ecology) (Serdar et al., 1999). As a result of this study, a single composite sample of eight smallmouth

bass (Micropterus dolomieu) fillets was found to contain 0.5 mg/kg mercury. Fish tissue mercury

concentrations in the range of 0.5 mg/kg were believed to be sufficiently high so as to pose a potential

health concern for some segments of the population, depending on the frequency and amount of fish

consumed.

To more thoroughly assess the mercury concentration and distribution in Lake Whatcom fish, a

comprehensive fish tissue mercury study was undertaken by the Whatcom County Health and Human

Services Department and the Washington State Departments of Ecology (Ecology), Health (DOH), and

Fish and Wildlife (WDFW). Fish species reported by the WDFW to be caught and consumed from Lake

Whatcom (Johnston and Mueller, 2000) were collected from each of the three lake basins. The species

included: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens), kokanee

(Oncorhynchus nerka), pumpkinseed (Lepomis gibbosus), cutthroat trout (Oncorhynchus clarki),

brown bullhead (Ameiurus nebulosus), and signal crayfish (Pacifastacus leniusculus). Skin-on fillet

samples from each fish were analyzed individually for total mercury. The analysis of individual samples,

as compared to composite samples, allows for the determination of mercury concentration variability by

species, fish size, and sample collection location. Study details and analytical findings from this effort are

documented in the report “Mercury Concentrations in Edible Muscle of Lake Whatcom Fish” (Serdar et

al., 2001).

Figure 1 Lake Whatcom Near Bellingham, Washington

Fish consumption information is essential for assessing the human health implications associated with the

consumption of chemically contaminated fish (CHEMRISK, 1994; Keenan et al., 1994; EPA, 1997).

While fish consumption data have been collected for a number of specific populations and locations in

Washington State (Pierce et al., 1981; McCallum, 1985; Landolt et al., 1985 & 1987; CRITFC, 1994; Toy,

1996; DOH, 1997), existing data were not sufficient for characterizing fish consumption by urban residents

living on or near a major fresh water lake such as Lake Whatcom. Reliance upon published default

consumption values was also not desirable due to the need for greater information specificity, which

included information on tuna consumption. To address these data needs, the Washington State

Department of Health and the Whatcom County Health and Human Services Department collaborated on

a survey to gather local fish consumption information from Lake Whatcom anglers. The goals of this

study were:

Ø To gather reliable information on the consumption of Lake Whatcom caught fish including: the

amount, frequency, and species consumed by local residents and area anglers, especially by women

of childbearing age and children, which could be used to generate a distribution of mercury intake

from Lake Whatcom fish,

Ø To gather information regarding these respondents’ perceptions and likely reactions to a fish

consumption advisory, and

Ø To gather information on the frequency of tuna consumption as well as demographic information on

the surveyed population.

Methods

Study Design

Rather than collecting information from a single sample of all local residents, the survey study design

focused on three target populations: residents who lived on the Lake’s shore or in developments with

direct access to the lake, boat anglers accessing the Lake through public or private boat launches, and

anglers using public access points for shore fishing. It was presumed that fishing practices and Lake

Whatcom fish consumption characteristics would vary among target populations. By differentiating these

target populations, the survey had a high probability of including Lake Whatcom fish consumers. A cross-

sectional sample from each of these target populations was selected as described below. Face-to-face

interviews were conducted using a structured instrument to collect fishing and detailed fish consumption

data from surveyed individuals as well as for other household members.

A four-week recall period was chosen for the collection of Lake Whatcom angler fish consumption

information in order to minimize recall error (Eisenhower et al., 1991). The four-week recall period

reflects a compromise between recall accuracy, ability to discern variation over time, and the efficient use

of limited resources. While shorter recall periods result in more accurate recall information, consumption

of specific species of fish taken from a specific location can be quite low and variable, leading to recall

estimates with an extremely high variance. Extending the recall period to four weeks was expected to

reduce this source of variability. A four-week recall period also reflects a toxicologically relevant

exposure duration, reflecting two to four times the interval over which fish consumption can reasonably be

averaged with regard to mercury exposure and toxicity.

Selection of the Residential Sample

Initial planning focused on the north end of Lake Whatcom, where the vast majority of Lake Whatcom

residents live, for survey data collection. The private community of Sudden Valley was initially targeted

for inclusion in the survey, however residential surveying was prohibited by the homeowners association

(D. Olson, personal communication). Based on land parcel geographic information system (GIS)

coverages provided by the Whatcom County Assessors Office (Judge, 2000) a total of approximately 1000

shore-side or near-shore residences with private or communal lake access were identified on the north end

of Lake Whatcom for inclusion in the survey, excluding Sudden Valley residences.

During preliminary visits to the survey area, it was noted that the general age and size of homes, and

therefore the value of the homes, appeared to vary greatly between locales. Based upon apparent

differences in home value as a surrogate indicator of resident lifestyle differences between locales, it was

postulated that fishing and fish consumption behaviors of residents might also vary between these locales.

To address this possibility, a two-stage sampling design was developed to increase the efficiency of

sampling. Through field observations, sixteen residential clusters were identified (Figure 2). Residential

clusters were defined based on age of neighborhoods, multi-family vs. single family housing types, and

neighborhoods with direct private access to the Lake-shoreline vs. neighborhoods with community beach

access. These clusters were stratified into five neighborhood types or strata: 1) high density (i.e.,

apartments/condominiums), 2) older single family residences/cabins with individual lake frontage, 3)

modern single family residences with individual lake frontage, 4) new single family residences with

individual lake frontage, and 5) modern single family residences with community lake access. Clusters

contained approximately 40-80 residences of similar characteristics. Clusters were randomly selected

from each strata (Table 1). The probability of selection varied across strata, as there were different

numbers of clusters per stratum. All residences within the selected clusters were included in the survey.

Figure 2. Lake Whatcom Fish Consumption Survey Residential Clusters and Surveyed Boat Launches

Boat and shore angler sampling

Lake Whatcom has two public boat launches and a private launch serving Sudden Valley, a large private

development. Interviews were conducted at the boat launch facilities located at Bloedel Donovan Park

and at Sudden Valley. These two boat launch facilities were reported by the Washington State

Department of Fish and Wildlife as well as by Whatcom County staff to be frequently used, while the third

boat launch, located on the south end of the lake, was reportedly seldom used and therefore not surveyed.

Popular shore fishing locations targeted for surveying included the children’s fishing pond in Whatcom

Falls Park and the bridge at the outlet of Lake Whatcom near Bloedell Donivan Park. Surveys were

conducted at boat launch facilities between 7:00 and 9:00 AM and between 7:00 and 9:00 PM on the three

study days. Shore fishing locations were visited numerous times during the survey day by roving survey

support staff.

Interviewer Training

The interviewers consisted of six students from Western Washington University, three staff from the

DOH, and two staff from Whatcom County Health and Human Services Department. Two, two-hour

interviewer survey training sessions covering the survey purpose, use of the survey instrument, the

importance of accurate data collection, and survey logistics, were held prior to the start of the survey.

Students were accompanied and supervised during the first day of the survey and demonstrated their

ability to competently administer the survey.

Data Collection

Door-to-door interviews of lake-shore residents were conducted by survey teams of two interviewers

within randomly selected residential clusters. Teams were assigned a cluster and approached every house

in that cluster. Houses where no one was home were revisited later that day or on the following day.

Residences with signs indicating that they did not want to be disturbed, or where unrestrained dogs or

other hazards existed, were classified as refusals. The person typically responsible for cooking for the

household was interviewed if he/she was available due to their improved recall of family dietary habits,

especially that of children (Nelson et. al., 1990).

To gather information on the consumption of Lake Whatcom caught fish from boating anglers, morning

and evening surveillance was conducted during the survey time frame at the Bloedel Donovan Park boat

launch and the boat launch in Sudden Valley (Figure 2). All boating parties entering or leaving the water

at these two boat launches were approached. Upon initial contact, the number of anglers in the fishing

party was recorded and a general question was directed to each angler asking whether they eat the fish

they catch from Lake Whatcom. From those in the group that indicated they eat the fish, a single

individual was selected for interviewing due to time constraints and due to interviewer inability to spatially

separate anglers so as to obtain unbiased responses. The selected angler was then asked detailed

questions regarding their consumption of Lake Whatcom caught fish, their consumption of tuna, and finally

questions pertaining to their demographic characteristics. Women were preferentially targeted for

interviewing due to the toxicology of mercury in fish (i.e., potential adverse health effects of mercury on

fetal development), and due to their generally greater awareness of foods eaten in the home. All observed

shore anglers were surveyed regarding their consumption of Lake Whatcom fish.

All interviews were conducted in person by trained interviewers using a structured survey instrument.

Questionnaires included questions regarding demographic characteristics, frequency of fishing, species-

specific consumption frequency, amount and duration of adult fish consumption, consumption by children

(residential survey), and perceptions regarding behavioral change associated with a theoretical fish

consumption advisory. Detailed fish consumption questions were only asked of individuals who responded

positively to an initial question regarding their consumption of Lake Whatcom caught fish. Color

photographs of popular Lake Whatcom caught fish species, as contained in the WDFW fishing regulations

booklet (WDFW, 2000), were used to minimize species miss-classification.

To quantify the amount of fish typically eaten during a fish meal, respondents who indicated they consume

fish from Lake Whatcom, were shown a scaled full color photograph of a salmon fillet on a plate, and

asked how much of the fillet pictured they would typically eat during a fish meal (Appendix B). While the

size of fish, depicted by the partial fillet photo was not typical of fish caught from Lake Whatcom, it did

provide an easily identifiable metric for quantifying the amount of fish mass typically consumed per fish

meal when catch was not the limiting factor. Responses to this question were recorded in terms of inches

of fish fillet according to the photo scale -bar.

After preparing the initial fillet photograph, the fillet was cut along one inch transects and each slice

weighed to the nearest tenth of a gram using an Acculab



VI – 10kg scale in order to establish a

correlation between fillet volume, as depicted by the photograph and fillet mass. Using this information,

the mass (grams) of fish tissue typically consumed per meal could be estimated from an individual’s

response.

While fish consumption questions were asked only of survey participants who indicated that they or a

member of their family eat fish caught from Lake Whatcom, demographic information was requested of

both consumers and non-consumers of Lake Whatcom fish at the completion of the survey. Demographic

information collected for statistical purposes included: age by category, number of persons and the

number of women between the ages of 18-45 years living at the residence, race and sex.

Data Reduction and Analysis

Survey data were entered into a Microsoft Access

database. A data entry screen, similar in appearance

to the actual survey form, was developed to improve data entry efficiency and quality. Survey forms were

labeled with a three-digit sequential unique identification number. This number was also assigned to the

record in the database, ensuring that surveys would not be entered twice into the database and allowed for

Quality Assurance/Quality Control (QA/QC) checking of database entries. Upon completion of initial data

entry, all records underwent a QA/QC check through data re-entry and review. Data tabulation and

statistical analyses were conducted using STATA

software (College Station, TX).

Survey Results

Results from this survey are initially presented separately for each of the three survey samples. Results

from aggregated survey data are then described.

Residential Sample

A total of 194 residential interviews were completed out of 386 survey attempts for a 50% response rate.

Of the 192 failed survey attempts, only 19 were refusals; in the remaining 173 cases there was no one at

home at the time of the initial contact or during subsequent visits (Table 1). Response rates ranged from a

low of 40 percent for strata one, which consisted of a high density apartment neighborhood, to a high of 64

percent for strata five, which consisted of modern individual residences with shared community lake

access.

Table 1. Residential Survey Interview Summary

Survey Interviews (n)

(Strata) Description

# Clusters

Surveyed

Out of Total

Attempts Refusals Completed

% Completed

(1) High Density, Shared 1/1 111 4 44 40

(2) Older, Lake Frontage 2/3 87 13 49 56

(3) Modern, Lake Frontage 2/7 73 0 43 59

(4) New, Lake Frontage 2/4 79 2 35 44

(5) Modern, Shared Access 1/1 36 0 23 64

Total 8/16 386 19 194 50

Demographic Characteristics

Slightly more females were interviewed than males (55% vs. 45%). The vast majority of survey

respondents were Caucasian (90%), with 42 percent between 46 and 65 years of age, and more than 71

percent of respondents 46 years of age or older (Table 2). Stratum four varied slightly from the other

strata with regard to age distribution in that 91 percent of respondents were 46 year of age or older and

only nine percent self reported to be in the 18 to 45 year old age bracket. Other demographic

characteristics were generally similar between strata.

Table 2. Residential Respondent Demographic Characteristics

Strata Overall

(%)

1 2 3 4 5

Gender (%)* (n=192)

Male 45 36 53 38 57 41

Female 55 64 47 62 43 59

Age (%)* (n=192)

<18 2 - - 5 - 5

18 - 45 25 34 20 30 9 32

46 – 65 42 23 51 35 59 45

66+ 29 39 24 26 32 18

Refused 3 5 4 5 - -

Race (%)* (n=193)

Caucasian 90 86 92 95 89 82

Hispanic 1 - 2 2 - -

Native American .5 - 2 - - -

Asian .5 - - - - 5

Other 4 5 - - 11 9

Refused 4 9 4 2 - 5

* Percentages may not add up to 100% due to rounding.

Fish Consumption

Twenty-two percent of residential survey respondents (n=42) indicated they or a member of their family

had fished on Lake Whatcom, while eleven percent of respondents (n=22) reported that they or a member

of their family eats fish caught from Lake Whatcom (Table 3). The percentage of respondents that fish

Lake Whatcom and eat the fish they catch, varied between strata. When asked about how long they have

been fishing and eating fish from Lake Whatcom, respondents indicated doing so for an average of 19.5

years (n=22, sd=16.3).

Table 3. Lake Whatcom Fishers and Fish Consumers By Residential Strata

Households That Fish

Lake Whatcom

Households That Eat

Lake Whatcom Fish

Strata

No. % of Surveyed No. % of Surveyed

No. Years L.W. Fish

Have Been Eaten

(mean±sd)

1 5 11 4

9 10.5±12.2

2 13 27 7

14 29.4±21.8

3 12 28 5 12 14.4±7.0

4 5 14 1 3 20

5 7 30 5 22 18±15.5

Total 42 22 22 11 19.5±16.3

*Includes one respondent that eats Lake Whatcom fish, but does not go fishing

To more fully enumerate the Lake Whatcom fish consuming population for the surveyed clusters,

respondents were asked about whom else in the household eats Lake Whatcom caught fish. In addition to

respondents (men, n=13 and women, n=9), surveyed households contained an additional 17 men, 6 women

(18-45 y/o), 6 women (>45 y/o), and 10 children.

The proportion of the surveyed population within each stratum that consumes fish from Lake Whatcom

ranged from 2.4 percent in stratum four, which consisted of new single family lake front homes, to 26

percent for stratum five, modern single family homes with shared community lake access. The proportion

of residents that consume Lake Whatcom fish was similar in stratum one and two (12 percent), and only

slightly greater in stratum three (15 percent). Overall, an estimated 12 percent of the surveyed residential

population consumed fish from Lake Whatcom.

Respondents who indicated that they consume Lake Whatcom caught fish (n=22), were asked detailed

questions about their fish consumption habits, even though they may not have eaten any of such fish during

the past four weeks (Table 4). The most commonly consumed Lake Whatcom caught fish specie was

cutthroat trout (n=14), followed by kokanee (n=10), smallmouth bass (n=9), perch (n=6), and crayfish

(n=4). Pumpkinseed and brown bullhead were each reportedly consumed by single respondents. The

mean number of fish typically eaten per meal varied by species, with respondents generally consuming

greater numbers of smaller fish species per meal. Lake Whatcom caught fish are generally consumed

three or fewer months per year.

Only three respondents, two men and one woman, reported eating fish from Lake Whatcom during the

four-week recall period prior to the survey. One respondent reported eating one meal of cutthroat trout,

the second respondent reported three meals of kokanee, and the last reported eating two meals of Lake

Whatcom caught fish, one of kokanee and one of smallmouth bass.

Table 4. Residential Sample Fish Consumption By Species

No. Fish Eaten Per Meal No. Months Per Year Fish Eaten

Species Mean Range Mean Range

Cutthroat Trout (n=14) 1.7 1 - 3 2.6 1 – 6

Kokanee (n=10) 1.7 0.5 – 3.5 2.4 1 – 6

Perch (n=6) 5.1 1 - 11 3.0 1 – 5

Smallmouth Bass (n=9) 1.8 1 – 4.5 2.6 1 – 4

Crayfish (n=4) 10.9 1 - 30 3.0 2 – 4

To assess whether fish consumption practices during the survey recall time frame were representative of

fish consumption practices throughout the fishing season, respondents were asked if there was another

time of year when they eat Lake Whatcom caught fish more frequently. Fourteen of the twenty-two

respondents (64%) reported eating Lake Whatcom caught fish more frequently during some other time of

the year, however, there was no clear pattern in the responses. Respondents indicated that Lake

Whatcom caught fish are primarily consumed between the months of April and September, with

“summer” being the most frequently provided response (n=4).

The average amount of fish consumed by adults during a typical meal, estimated using salmon fillet photo

described above, was 225 grams (sd=67) with meal sizes ranging from 65 to 301 grams. Men (n=12)

reportedly consume on average 237 grams per meal (sd=55), which was slightly more than the amount

reported by women (n=9) (mean=209, sd=81), although not significantly different.

Gathering information on the consumption of Lake Whatcom fish by children (< 18 y/o) was of particular

interest in the design and conduct of this survey. Five of the surveyed fish consuming households also

contained children (n=10), who ranged in age from two to seventeen years with a median age of 13.5

years. Six of nine of these children were males. Children reportedly ate the same fish species as their

parents, while none had consumed Lake Whatcom caught fish during the past four weeks. The amount of

fish consumed per meal, based on the salmon fillet photo described above, ranged from 99 grams to 265

grams for children eight to seventeen years of age, with a median consumption of 131 grams per meal.

Consumption of Canned Tuna

Respondents who consume Lake Whatcom fish were also asked about the number of times they

consumed canned or fresh tuna during the past four weeks. Respondents (n=19) consumed tuna an

average of 4.2 times, with individual consumption ranging from one to twenty-eight times during the prior

four weeks. Men (n=12) and women (n=7) both reported a media n tuna consumption of 2 meals during

the four week period, with tuna consumption by men ranging from one to twenty-eight meals (mean=5;

sd=7.6), while consumption by women ranged from one to six meals (mean=3; sd=1.7).

Response to Health Advisories

To assess public perceptions related to health advisories for contaminated fish, three questions were asked

pertaining to a hypothetical fish consumption advisory. The first focused on feeding children fish from a

posted water body, the second question focused on adult consumption of fish from a posted water body,

and the third focused on the best ways to communicate advisory recommendations. Regarding the

hypothetical advisory, three of four respondents with children stated they would stop feeding their children

any fish from Lake Whatcom. The fourth respondent indicated they would continue to feed their child

Lake Whatcom fish, but that they would follow the recommendations of the advisory. Nearly half of the

adults (10/21) indicated they would continue eating fish from Lake Whatcom following the

recommendations in the advisory, while 38 percent (n=8) indicated they would stop eating any Lake

Whatcom fish, and the remainder of respondents (n=3) would continue eating Lake Whatcom fish

unabated. Lake Whatcom fish consumers were asked to indicate their preferred method(s) for receiving

advisory information. Responses in order of declining preference were: newspaper, radio, signs, and in

the fishing regulations booklet.

Boat Angler Sample

As a result of morning and evening boat launch surveillance, sixteen boat angling parties were contacted;

fifteen at the Bloedel Donovan Park boat launch and one at the Sudden Valley boat launch. The median

fishing party size was two persons, while a total of 38 anglers were represented overall. Of these anglers,

71 percent (n=27) reported eating at least some of the fish they catch from Lake Whatcom.

Descriptive Characteristics

Responses from the detailed surveys (n=16) revealed that most surveyed anglers were male (88 percent),

of Caucasian race (88 percent), and between the ages of 18 and 45 years (88 percent). Three of the

sixteen anglers surveyed reported that this was their first time fishing on Lake Whatcom. Of the surveyed

anglers who repeatedly fish Lake Whatcom (n=12), over half did so less than once per month, while the

upper quartile of anglers reported fishing on the Lake an average of nine times per month (sd=7). When

returning anglers were asked about the number of years they have fished on Lake Whatcom, responses

ranged from one to sixty years with a median duration of six years. While six anglers responded that they

eat Lake Whatcom fish more frequently during a particular time of year, no particular season was more

frequently identified than any other. The majority of surveyed boat anglers (82%) lived in western

Whatcom County in the vicinity of Lake Whatcom.

Fish Consumption

Surveyed boat anglers (n=9) reported consuming cutthroat trout (n=6), smallmouth bass (n=4), crayfish

(n=1), kokanee (n=1), and perch (n=1). Anglers who consume cutthroat trout reported eating either one

or two fish per meal (mean=1.4) and consumers of smallmouth bass reported eating one to four fish per

meal (mean=2). Cutthroat trout and smallmouth bass were consumed three or fewer months per year.

Regardless of species, 78 percent of surveyed anglers consumed Lake Whatcom species two or fewer

months per year. Only one of the anglers interviewed reported consuming any Lake Whatcom fish during

the prior four week period, even though that angler reported fishing on Lake Whatcom an average of 4.3

times per month.

To quantify the amount of fish an angler typically consumes per meal, surveyed anglers who reported

eating Lake Whatcom fish were shown the fillet photo described previously, and asked about how much of

this fillet they eat during a typical fish meal. The reported amount of fish consumed per typical fish meal

by these anglers (n=10) ranged from 186 grams to 301 grams, with an average meals size of 264 grams

(sd=39) i.e., slightly greater than one half pound of fish per meal. Six of the sixteen surveyed anglers

reported having eaten fresh or canned tuna during the four week survey recall period at frequencies

ranging from one to eight times (mean=3.3, sd=2.9).

When these anglers were asked how they would respond to a hypothetical health advisory for a particular

species of fish, a majority of anglers (62 percent) indicated they would continue to eat the fish, making

sure to follow the recommendation contained in the advisory, while 31 percent indicated they would stop

eating any fish from that location. Preferred methods, in declining order, of communicating advisory

information were: posted signs, newspaper, fishing regulations, and radio.

Shore Angler Sample

Descriptive Characteristics

Ten shore anglers were interviewed during random visits to popular shore fishing locations over the three

survey days. All observed anglers were approached and at least one angler in each party was

interviewed. A majority of the anglers (n=7) were interviewed while fishing at or near the Whatcom

Creek bridge at the north end of Lake Whatcom. Two anglers were interviewed while fishing at the youth

fishing pond adjacent to Whatcom Creek. One male angler was also interviewed while fishing from the

shore at Sudden Valley. Three of the anglers interviewed where less than eighteen years of age, while

five were 18-45 years of age. Nine out of ten anglers reported that they or household members eat fish

from Lake Whatcom, while three anglers reported this to be their first time fishing on Lake Whatcom or

adjacent waters. Eight of ten interviewed anglers were Caucasian, and two anglers were African-

American.

Fish Consumption

Lake Whatcom shore anglers who repeatedly fish the lake (n=7) did so an average of 8.4 times per month

(sd=5.1), and had been doing so an average of nine years (sd=9.1). The estimated typical amount of fish

anglers eat per meal, based on the fish fillet photograph, ranged from 131 grams to 301 grams

(mean=249). Four anglers also reported consuming canned or fresh tuna between two and five times

during the previous four week period (mean=4.0, sd=1.4).

Lake Whatcom shore anglers (n=7) reported catching and consuming the following species: smallmouth

bass (n=7), cutthroat trout (n=5), perch (n=4), and pumpkinseed (n=1). These anglers reported consuming

an average of 1.1 (sd=.55) trout, 1.3 (sd=.49) bass, or 2.3 (sd=1.3) perch per fish meal. All species were

reportedly consumed two to three months out of the year.

During the four weeks prior to the survey, four of ten interviewed anglers reported having eaten fish from

Lake Whatcom, with the reported number of fish meals ranging from 1 to 10 (mean=4.0). These

respondents reported consuming an average of 2.4 meals of smallmouth bass. Perch were eaten by two

anglers at one and two meals respectively, while cutthroat trout and pumpkinseed were each eaten by one

angler during the four week recall period. One respondent reported consuming four meals of Lake

Whatcom caught fish and five meals of tuna during the previous four week recall period.

In response to the question pertaining to a hypothetical advisory for a particular fish species, five of seven

interviewed anglers reported that they would continue eating fish from Lake Whatcom, making sure to

follow the recommendations contained in the advisory, while the other two anglers reported that they

would stop eating any fish from Lake Whatcom. In response to questions pertaining to dissemination of

fish consumption advisory information, preferred methods in declining order of preference were:

newspaper, posted signs, regulation booklet, and radio.

Estimation of Total Population Consuming Lake Whatcom Fish

Stratum-specific population estimates were calculated using the number of households in each stratum and

the mean number of persons per household in each stratum. Parcel data provided by the Whatcom

County Assessors Office (Judge, 2000) were used to determine the total number of households by stratum

within the survey area. The mean number of persons per household varied from 1.55 (±0.21, 95% C.I.) to

3.13 (±0.62) between sample strata (Table 5). The weighted average household population across

surveyed clusters is estimated to be 2.66 (±0.60) persons. Weighting accounts for the probability of

selecting a particular cluster within a particular cluster type. The total population of surveyed clusters is

estimated to be 503 persons of which 61 persons (12%) are likely to consume fish from Lake Whatcom.

Of this population, 49% were reported to be males over eighteen years of age, 23% were reported to be

women over 45 years of age, 17% were children 18 years of age or younger, and 11.5% were women

between the ages of 18 and 45 years.

Table 5. Residential Lake Whatcom Fish Consumer Population Estimates

Strata

No. Surveyed

Households*

Persons Per

Household

Mean (±CI

95%)

Surveyed

Cluster

Population

Res. Fish

Eaters

# (%)

Total No.

Households

In Study Area

Est. Study

Area

Population

Est. No. LW

Fis h Eaters

1 44 1.55 (0.21) 68 8 (12) 111 172 20

2 47 2.34 (0.30) 110 13 (12) 130 304 36

3 40 3.15 (0.44) 126 19 (15) 457 1440 217

4 35 2.43 (0.35) 85 2 (2.4) 263 639 15

5 23 3.13 (0.62) 72 19 (26) 42 131 35

Total (w) 189 2.66 (0.60) 503 61 (12) 1003 2668 320

* Excludes five households which did not provide residence population information.

(w) Weighted values based on probability of cluster selection within a particular cluster type.

Population estimates and fish consumer counts from the surveyed clusters were used to estimate the

population and number of Lake Whatcom fish consumers for the entire study area, i.e. the northwest end

of Lake Whatcom (Table 5). Based on proportion estimates from the surveyed clusters, the population of

Lake Whatcom fish consumers was estimated for the study area. The surveyed area represents a

population of approximately 2668 persons, of which 320 persons are estimated to consume fish caught

from Lake Whatcom.

Calculation of Fish Consumption Rates

To evaluate the amount of Lake Whatcom fish tissue consumed by residents, the number of fish of each

species reportedly consumed at a typical meal was combined with fillet weight data gathered as part of the

recent Lake Whatcom mercury study (Serdar et al., 2001). First, specie -specific mean fillet weights were

calculated using data from all fish caught (Table 6). These fish were obtained through electro-shocking so

the sample included fish of all sizes present in the lake. To correct for a potential downward bias which

might occur as a result of anglers not keeping small fish, specie -specific mean fillet weights were

calculated using only the largest 80% of fish of each specie. While no Lake Whatcom angler catch or

creel data are available to support the assumption that smaller fish are not kept, the net result is an

increase in the mean fillet weight of 5-18% across species. The mean fillet weight for the two most

commonly consumed species, smallmouth bass and cutthroat trout, increased 15 and 16 percent,

respectively.

Table 6. Lake Whatcom Fish Species Fillet Weights.

All Fish Larger fish (excludes lower 20%)

Fish Species

Sample

Size

Fillet Wt.

Mean±sd (gms)

Sample Size Fillet Wt.

Mean±sd (gms)

Avg. Fillet Wt.

Change (%)

Brown Bullhead 13 67.9 ±45.7 11 75.9 ±45.2 12

Crayfish 45 3.7 ±1.4 37 3.9 ±1.4 5

Cutthroat Trout 30 36.5 ±32.6 24 42.4 ±33.9 16

Kokanee 30 25.2 ±6.8 24 26.6 ±6.6 6

Pumpkinseed 30 15.9 ±8.9 24 18.3 ±8.3 15

Smallmouth Bass 95 190.9 ±108 76 219.8 ±102 15

Yellow Perch 30 42.1 ±45.6 24 49.7 ±48.1 18

Data from the residential (n=20), boat (n=9), and shore (n=8) surveys regarding the number of fish

typically consumed at a meal were multiplied by the mean fillet weight data from the largest 80 percentile

of fish caught, in order to estimate the amount of fish of each species consumed during a typical meal

(Table 7). Survey catch data are assumed to reflect typical fish consumption patterns, since survey results

indicate that fish catch and consumption is greatest during the summer months (i.e., when the survey was

conducted). Lake Whatcom fish consumers from the residential sample generally consume a wider

variety of fish species than do boat or shore anglers. Regardless of target population, anglers who

consume smallmouth bass generally consume more smallmouth bass per meal than any of the other

commonly caught fish species. Of the fish species commonly consumed from Lake Whatcom, responses

indicate that cutthroat trout are consumed by more anglers than the other species, although the amount of

cutthroat trout consumed per meal is less than the amount of yellow perch or smallmouth bass consumed

during a fish meal.

Table 7. Estimated Species-specific Fish Meal Sizes For Commonly Caught and Consumed Lake

Whatcom Fish Species.

Sample Species Crayfish

Cutthroat

Trout Kokanee Yellow Perch

Smallmouth

Bass

Residential Sample

Sample Size (n) 4 14 10 6 9

Fish Meal Size

Median (gms/meal)

IQR

(11 – 74)

(42 – 106)

(27 – 66)

162

(99 – 497)

220

(220 – 440)

Boat Angler Sample

Sample Size (n) - 6 - - 4

Fish Meal Size

Median (gms/meal)

IQR

(42 – 85)

- -

330

(220 – 659)

Shore Angler Sample

Sample Size (n) - 5 - 4 7

Fish Meal Size

Median (gms/meal)

IQR

(42 – 42)

(75 – 149)

220

(220 – 440)

IQR – Inner Quartile Range i.e., 25

– 75

percentile

Conclusions

This study was undertaken to gather quantitative information on the catch and consumption of fish from

Lake Whatcom by near-shore residents, boat anglers and shore anglers, for use in assessing the human

health implications of mercury in various fish species. Lack of existing fish consumption information from

a similar urbanized lake in Washington necessitated this study. While the shore angler and boat-angler

samples specifically targeted individuals who were catching fish from Lake Whatcom, the residential

sample targeted the shoreline residential population, which included anglers as well as non-anglers.

Early in the assessment process, anecdotal reports suggested that Lake Whatcom supported a sizable

recreational fishery with anglers frequently consuming a wide variety of fish species including crayfish.

Information gathered from this study supports these reports, however, the number of persons that fish

Lake Whatcom is but a small proportion of the local population, with the proportion that consumes fish

from Lake Whatcom being even smaller. Results from this survey suggest that less than two percent of

the surveyed residential population had consumed any Lake Whatcom caught fish during the four weeks

prior to the survey and that the remainder of the population would consume such fish at a rate less often

than one meal per month. Of the three target populations, shore anglers consume Lake Whatcom caught

fish most frequently, with nearly half of these respondents having eaten such fish during the previous four

weeks. Across survey populations, anglers reported eating cutthroat trout, followed by small mouth bass,

kokanee, and perch from Lake Whatcom three or fewer months out of the year. Those that are catching

and eating fish are primarily the older segment of the population and primarily males. While few fish

consuming households contained children, it was reported that younger children (>8 years of age) eat Lake

Whatcom caught fish at the same frequency as the adult household members.

Survey results from the residential, shore, and boat populations suggest that fish meal sizes for locally

caught fish is limited by fish size and catch, (i.e., the larger the fish, the larger the size of the fish meal).

As an example, median fishmeal sizes for cutthroat trout ranged from 42 to 53 grams per meal across

survey samples. Median meal sizes for smallmouth bass ranged from 220 to 330 grams per meal. This

difference in meal size is attributable to bass having a larger mass of edible tissue compared to cutthroat

trout and not the number of fish consumed per meal. When asked about the typical amount of fish

consumed per meal when quantity of fish is not the limiting factor, survey respondents reported consuming

an average of 240 grams of fish per meal, with sample population averages ranging from 225 for the

residential population to 264 for the boat population. The discrepancy between reported fish meal size

based on consumption of locally caught fish verses reported meal size based on the fillet photograph,

reinforces the conclusion that angler consumption of Lake Whatcom caught fish is limited by catch and

that fish consumers, given an ample quantity of fish, would consume about one half pound (227 grams) of

fish per meal. Additionally, these findings suggest that species specific consumption information is

necessary to consider when conducting an environmental health assessment.

During the four-week recall period, survey respondents who consume Lake Whatcom fish also reported

consuming canned or fresh tuna averaging one meal per week. While this survey did not gather

information on the amount of tuna consumed per meal, the frequency with which tuna was consumed by

Lake Whatcom fish consumers, and the fact that tuna averages 0.17 mg/kg methylmercury (Yess, 1993),

suggests that tuna consumption may be a more significant source of mercury exposure for many local

residents than the consumption of Lake Whatcom fish due to tuna consumption frequency.

Responses from this survey suggest that just over half of adult anglers (56 percent) would follow the

recommendations of an advisory, if one were issued for Lake Whatcom. Anglers with children on the

other hand, indicated they would tend to stop feeding their children any fish from the posted location.

Since study results indicate that the frequency with which shore anglers consume Lake Whatcom fish is

greater than that of the other groups, health education materials should be designed with this population in

mind. Health educators preparing information for Lake Whatcom will be challenged by the preparation of

information which results in improving public health through reduced mercury exposure, yet does not

create panic causing families to discontinue eating fish. This task will be complicated to an even greater

degree given the potential health significance of mercury in canned tuna and the more frequent

consumption of tuna relative to fish caught from Lake Whatcom.

The small number of anglers and the small proportion of the residential population that actually consumed

any Lake Whatcom caught fish during the four week recall period prior to the survey, limited our ability to

fully quantify fish consumption characteristics of the local population, especially women and children.

These findings however, indicate that the majority of anglers consume fish from Lake Whatcom at a rate

of less than one meal per month and that anglers consume Lake Whatcom caught fish three of fewer

months out of the year. This study also identified the presence of a small proportion of anglers that

consume fish from Lake Whatcom on a weekly basis and in amounts, which may be sufficient to pose a

health risk due to environmental contamination. While reported fish consumption rates, based on the

consumption of locally caught fish, reflect rates constrained by external factors, estimates of consumption

based on the fillet photo provide a good upper bound rate estimate for conducting exposure analyses.

Bibliography

ATSDR. 1999. Toxicological Profile for Mercury (update). Agency for Toxic Substances and Disease

Registry. Atlanta, GA.

CHEMRISK. 1994. Selection of Fish Consumption Estimates for Use in the Regulatory Process.

Chemrisk.

CRITFC (Columbia River Inter-Tribal Fish Commission). 1994. A Fish Consumption Survey of the

Umatilla, Nez Perce, Yakima, and Warm Springs Tribes of the Columbia River Basin. CRITFC

Technical Report No. 94-3. Portland, OR.

DOH. 1997. Consumption Patterns of Anglers Who Frequently Fish Lake Roosevelt. Washington State

Department of Health. Olympia, WA.

Eisenhower, D., N. Mathiowetz and D. Morganstein. 1991. Recall Error: Sources and Bias Reduction

Techniques. In Measurement Errors in Surveys, P. Biemer et al., (eds.). John Wiley & Sons, Inc.,

New York.

EPA. 1998. Guidance for Conducting Fish and Wildlife Consumption Surveys. EPA-823-B-98-007.

U.S. Environmental Protection Agency, Office of Water. Washington, DC.

EPA. 1997. Guidance for Assessing Chemical Contaminants for Use in Fish Advisories. Volume II.

Risk Assessment and Fish Consumption Limits. 2

edition. EPA-823-B-97-009. U.S. Environmental

Protection Agency, Office of Water. Washington, DC.

Johnston, J. and K. Mueller. 2000. Lake Whatcom Fish Tissue Collection Proposal For May, 2000.

Washington Dept. of Fish and Wildlife, Olympia, WA. Personal communication.

Judge, J. 2000. Whatcom County Assessors Office. Electronic transfer of land parcel data. Bellingham,

WA.

Keenan, R., B. Finley, and P. Price. 1994. Exposure Assessment: Then, Now, and Quantum Leaps in

the Future. Risk Analysis.

Landolt, M. F. Hafer, A Nevissi, G. Van Belle, K. Van Ness, and C. Rockwell. 1985. Potentia l Toxicant

Exposure Among Consumers of Recreationally Caught Fish From Urban Embayments of Puget

Sound. NOAA Technical Memorandum No. OMA 23. National Oceanic and Atmospheric

Administration. Rockville, MD.

Landolt, M. F. Hafer, A Nevissi, G. Van Belle, K. Van Ness, and C. Rockwell. 1987. Potential Toxicant

Exposure Among Consumers of Recreationally Caught Fish From Urban Embayments of Puget

Sound: Final Report. NOAA Technical Memorandum No. OMA 33. National Oceanic and

Atmospheric Administration. Rockville, MD.

McCallum, M. 1985. Seafood Catch and Consumption in Urban Bays of Puget Sound. Washington State

Department of Health. Olympia, WA.

Nelson, L., W. Longstreth, T. Koepsell, and G. van Belle. 1990. Proxy respondents in epidemiological

research. Epidemiologic Reviews. 12:71-86.

New York. 1999. 1996 Survey of Hudson River Anglers, Hudson Falls to Tappan Zee Bridge at

Tarrytown, New York (Health Consultation). New York State Department of Health, Center for

Environmental Health. Albany, NY

NRC (National Research Council). 2000. Toxicological Effects of Mercury. National Academy Press.

Washington, DC.

Olson, D. 2000. General Manager, Sudden Valley Community Association, Sudden Valley, WA

Personal communication with D. McBride, DOH, Office of Environmental Health Assessments.

Olympia, WA.

Pierce, D., D. Noviello, and S. Rogers. 1981. Commencement Bay Seafood Consumption Study.

Tacoma-Pierce County Health Department. Tacoma, WA.

Serdar, D. D. Davis, and J. Hirsch. 1999. Lake Whatcom Watershed Cooperative Drinking Water

Protection Project – Results of 1998 Water, Sediment and Fish Tissue Sampling. No. 99-337.

Washington State Department of Ecology. Olympia, WA.

Serdar, D., K. Mueller and G. Patrick. 2001. Mercury Concentrations in Edible Muscle of Lake

Whatcom Fish. No. 01-03-012. Washington State Department of Ecology. Olympia, WA.

Toy, K., N. Polissar, S. Liao, and G. Mittelstaedt. 1996. A Fish Consumption Survey of the Tulalip and

Squaxin Island Tribes of the Puget Sound Region. Tulalip Tribes, Dept. of Environment. Marysville,

WA.

WDFW (Washington State Department of Fish and Wildlife). 2000. Sport Fishing Rules: Fishing In

Washington. Olympia, WA.

Yess, N. 1993. U.S. Food and Drug Administration Survey of Methyl Mercury in Canned Tuna. Journal

of AOAC International. 76(1):36-38.

APPENDIX A

Lake Whatcom residential fish consumption survey form.

LAKE WHATCOM RESIDENTIAL

FISH CONSUMPTION SURVEY

Interviewer: _________ Cluster #: _______

Survey Date: _____/_____/00

1. Do you or any member of your family go fishing on Lake Whatcom? Yes  No 

DK 

2. Do you or any member of your family eat fish caught from Lake Whatcom? Yes  No 

(Skip to 14) DK 

Now, I’d like to ask you some specific questions about the fish you eat from Lake Whatcom.

3. For how many years have you eaten fish caught from Lake Whatcom? ___________

years (0,1,2,3, etc.)

4. In the past 4 weeks, how many times have you eaten fish caught from Lake Whatcom? ____________

(enter number of meals)

5. Is there a time during the year when you eat Lake Whatcom fish more often than this? Yes 

No 

(If YES , when?

__________________________)

(Enter Month)

6. Now I’d

like to ask some specific questions regarding your consumption of fish from Lake Whatcom:

Which Species of Lake Whatcom

Fish Do You Consume?

Do you eat……….?

(Check all species eaten – show pictures)

How Many Times Have You

Eaten This Species During

the Past 4 Weeks?

(Enter Number)

How Many Fish Do

You Typically Eat

Per Meal?

(Enter Number)

How Many Months Per Year Do You

Species of Lake Whatcom fish?

(Enter Number)

(a)  Brown Bullhead ___________ mo/yr

(b)  Crayfish (Crawdads) ___________mo/yr

(d)  Kokanee ___________mo/yr

(e)  Perch ___________mo/yr

(f)  Pumpkinseed ___________mo/yr

(g)  Smallmouth Bass ___________mo/yr

(h)  Other:

_________________________

___________mo/yr

7. (Display picture of fillet) During a typical meal, about how much of a fillet like this would you eat?

___________ (Enter number)

8. During the past 4 weeks, how many times have you eaten canned or fresh tuna? __________ (Enter

number)

9. Who else in your household eats fish from Lake Whatcom? How many…

Men  Women  Women  Children

(18 – 45 y/o) (>45 y/o) if no children,

SKIP to Q12

10. Now I’d like to ask you about your children’s consumption of Lake Whatcom fish, starting with your youngest

child.

How Old Is

This Child?

(note if ‘months’)

Is this child a

boy or girl?

(record M or F)

How Many Times Has This Child

Eaten Lake Whatcom Fish

During the Past 4 Weeks?

(Enter Number or ‘NONE’)

During a Typical Meal,

About How Much of This

Fillet Would They Eat?

(Enter line number)

Does This Child Eat The Same

Species of Lake Whatcom Fish

as You?

(yes/no; if NO, explain)

(a)

(b)

(c)

(d)

(e)

Now I’d like to end this survey with a few hypothetical questions. Suppose that local Government issued a health

advisory for

one species of Lake Whatcom fish, recommending that people should not eat more than, say, 2 meals of this kind of

fish per month.

11. First, concerning your children, do you think you would: (check only one)

a)  Stop feeding them any fish from Lake Whatcom,

b)  Continue feeding them fish from Lake Whatcom, but make sure to follow all the recommendations, OR

c)  Continue feeding them fish from Lake Whatcom without worrying too much about what they eat?

12. Now, concerning your own consumption of Lake Whatcom fish, would you: (check only one)

a)  Stop eating any fish from Lake Whatcom,

b)  Continue eating fish from Lake Whatcom, making sure you followed all the recommendations, OR

c)  Continue eating fish from Lake Whatcom without worrying too much about what you eat?

13. What would be the best way to get fish consumption advisory information to you? (Read choices, mark all that

apply)

Posted Signs  Fishing Regulations  Newspaper  Radio  Other 

___________________________ DK 

14. Demographic Information (for statistical analysis):

(a) Which category best describes your age? (check only one) <18  18-45  46-65  66+ 

Refused 

(b) How many people total live at this residence? (Enter number )

Refused 

(d) How would you describe your racial/ethnic background? (Read choices, mark all that apply)

Caucasian  Hispanic  Native American  African-American  Asian  Other 

Refused 

(e) Respondent gender: M  F 

THANK YOU FOR YOUR HELP. WOULD YOU LIKE A COPY OF THE RESULTS OF THIS STUDY?

(If YES, give the respondent a study request card).

APPENDIX B

Salmon fillet photo used during the survey to quantify a typical fish meal

size.