David A. Best - FWS

Assessment of Mercury in Edible Fish Filletsat Seney National Wildlife Refuge

David A. Best

September 1999

Study Identifier: 3N24

Environmental Contaminants ProgramDivision of Ecological Services

East Lansing Field OfficeU.S. Fish & Wildlife Service

Assessment of Mercury in Edible Fish Fillets at Seney National Wildlife Refuge

Background

This report is a follow-up to work conducted by the East Lansing Field Office (ELFO) atSeney National Wildlife Refuge (NWR) in 1987-88 to assess the presence and degree ofcontamination in soils and biota due to historic onsite management activities (Best et aJ.1995). While the onsite activiti~s were found not to have impacted biota, fish collected fromseveral ponds on the refuge were found to have elevated levels of mercury (Hg) in whole fishand skinless fillets. Levels ofHg in the larger northern pike (Esox Juc;us) exceeded State andFederal criteria for human consumption and interstate trade, respectively (>0.5 and >1.0 ug/gHg, wet weight, respectively). The sources of the Hg are unknown but may be attributable toaerial transport and deposition from combustion processes at industrial facilities within andoutside the Great Lakes basin. Degradation of parent soils and bedrock may also be a localsource ofHg. However, the 1987-88 data for Hg in fish were compromised by poor QualityAssurance/Quality Control (QA/QC) practices by the laboratory contracted by the PatuxentAnalytical Control Facility (PACF), U.S. Fish & Wildlife Service. PACF reanalyzed a subsetof the samples and confirmed the elevated levels ofHg in the fish. Due to the poor QA/QCpractices by the contract laboratory and the limited sample size, ELFO concluded it would bepremature to recommend altering the management direction at Seney NWR regarding accessand consumption of fish by humans and wildlife. ELFO recommended that additional fishcollections be undertaken for Hg analysis in the future. ELFO further recommended that ifHg continues to be a problem, then an expanded long term assessment of Hg in fish beimplemented. The present report documents the results of this expanded sampling effort as itrelates to human consumption of fish from Seney NWR. The risks to fish-eating wildlife willbe addressed in a separate report.

In 1989 the Michigan Department of Community Health (MDCH) issued a specialconsumption advisory for Hg in fish for all inland lakes in the State. This was based on thecollection and analysis of fish of various species from about 200 lakes statewide. Theadvisory applies to all inland lakes regardless of whether they were sampled. The only lakesexempted from the advisory were those sampled lakes where fish did not exceed the criteria.No pools or streams were sampled within Seney NWR. Therefore, the special consumptionadvisory for Hg in fish from inland lakes applies to Seney NWR. The general advisory forinland lakes applies to rock bass (Amb/op/ites rupestris), yellow perch (Percaflavescens), orcrappie (Pomoxis sp.) over 228.6 mm (9 in) in length, or bass (Micropterus d%mieui and Msa/moides), walleye (Stizostedion vitreum), northern pike, or muskellunge (&oxmasquinongy) of any size. Of these fish covered under the general advisory, the northernpike, yellow perch and black crappie (P. nigromacu/atus) are known to occur in refuge pools.Walleye and smallmouth bass are known to occur in the Manistique River and may be found inthe reach of the river within Seney NWR.

In 1998 the criteria for placing fish on the advisory were changed by the MDCH from thoseu.sed in previous years. For fish exceeding 1.5 ug/g Hg, wet weight (wet wt.), noconsumption offish is advised. For fish in the range of 0.5-1.5 ug/g Hg, wet wt., a limitedconsumption of one meal per week is advised for the general population, and one meal permonth is advised for pregnant women, nursing mothers, women who plan to have children,and children under 15 years of age.

The ~CH has also issued specific consumption advice for Hg in the Manistique Riverupstream of the dam in Manistique. This includes the section of the river within Seney NWR.For northern pike greater than 558.8 mm (22 in) in length. a limited consumption of one mealper week is advised for the general population, and one meal per month is advised forpregnant women. nursing mothers. women who plan to have children, and children under 15years of age. No advisory is issued for northern pike less than 558.8 mm in length.

Information on the consumption advice for Hg in Michigan fish may be obtained from theMDCH's website at: www.mdch.state.mi.us/pha/fish/mercury.htm.

The U.S. Food and Drug Administration (USFDA) has established a Tolerance Level for Hgin fish for interstate commerce at 1.0 ug/g. wet wt.

Fish consumption is also controlled through the setting of minimum sizes for hook and linesport fishing. The Michigan Department of Natural Resources, Fisheries Division has set aminimum size for northern pike at 609.6 mm in length (24 in) statewide. However, underspecial regulations and exemptions, Seney NWR has no size limits for northern pike takenfrom its pools. In addition, no State limits on minimum size are set for yellow perch, whitesucker (Catostomus commersoni) and pumpkinseed (Lepomis gibbosus) statewide, the otherspecies addressed in this report.

Portions of Seney NWR are open to public access for sport fishing. Pools C3, E, F, G, H, Iand J are open for fishing from May I5-September 30, while Pools CI and D are open onlyduring the month of September (Figure I). In addition, the portions of the Manistique River,Driggs River, Creighton River, and Walsh Creek and Ditch on the Seney NWR are also opento fishing during regular state seasons.

Methods

Field CollectionsFish were collected in 1996 and 1997 from 12 managed pools within Seney NWR (Figure 1).In 1996, staff from the Ashland Fisheries Resources Office (FRO) and the Green Bay FROcollected 17 fish from J and G pools on the nights of July 17-18 using an 18-footelectrofishing boat (600 volts DC at 2 amps). In 1997, staff from the Green Bay FROcollected 70 fish from C3, D, and Marsh Creek pools on July 22-24 and from AI, A2, and H

2

pools on August 18-19 using an 18-foot electrofishing boat (400-600 volts DC at 3-4 amps).Most collections were made at night during the regularly scheduled fishery assessments ofthese pools. A single pass was made along the shoreline of each pool and all stunned fishwere collected. However, collections from D and A2 pools were made during the dayexpressly for the purpose of collecting contaminant samples for this project, so only certainspecies and sizes were targeted. These collections were supplemented by Seney NWR staffwho collected 38 fish from AI, A2, C2, D, G, I and Marsh Creek Pools, and from theRiverside Dike Pools along Driggs River using hook and line and gill nets in the period ofJune 4-13, 1997.

After capture, fish collected using electrofishing were measured to the nearest mm, weighedto the nearest gram. and scales removed from those fish greater than 100 mm for later aging.Fish collected using hook and line and gill nets were measured to the nearest inch. Each fishwas individually wrapped in aluminum foil, labeled, placed in a plastic bag, prior to freezing atSeney NWR. Fish were later transferred frozen to ELFO for sample preparation andprocessing.

Sample Preparation and ProcessingA total of 125 fish from four species were processed by ELFO for analysis. Since weight andlength measurements were not consistently taken during field collections, each fish was againmeasured in the laboratory. Each fish was thawed, and measured for total body length (to thenearest 5 rom) and whole fish weight. Lengths and weights from frozen specimens are knownto be altered from similar measurements from fresh specimens. At least one scale wasremoved from the side of the fish and archived for possible future aging. To evaluate tworoutes of exposure, paired fillet samples were prepared from each fish; one fillet with the skin-off and the other with the skin-on. Since Hg predominantly resides in muscle tissue within thebody, the removal of the skin from a fillet should constitute the worst case scenario of humanexposure to Hg via consumption. Each fillet sample was weighed, wrapped in aluminum foil,labeled, placed in a plastic bag and refrozen. A total of 250 samples were shipped viaovernight express delivery to P ACF for analysis.

Analytical ChemistryAll samples were analyzed by P ACF for Hg using the cold vapor atomic absorption method(Monk 1961) with the results reported to three significant digits. The nominal lower limit ofdetection was 0.05 ug/g Hg, wet wt. In addition. percent moisture was determined for eachsample to permit reporting of the results by P ACF on both a wet and dry weight basis.QA/QC was monitored through the analysis of duplicate samples, procedural blanks, spikedsample recoveries, and standard reference material samples (dogfish liver). Based on theQA/QC program, P ACF identified the following three anomalies:

1. The relative percent difference for one of the 19 Hg duplicates was slightly higherthan is normally seen,2. The" recovery ofHg from one of 19 spiked samples was slightly higher thannormally seen, and

3

3. The recovery of Hg from one of 19 reference material analyses was slightly lowerthan is normally seen.

P ACF concluded that these anomalies should have no affect on the interpretation of the data.

Data InterpretationThe results for Hg in skin-off and skin-on fillets were compared to the MDCH and theUSFDA criteria for exceedences that would suggest the need for consumption advisories.The results were also compared to the 1988 data set to assess any change in concentrationover time. For each species, linear correlation analysis was performed to establish arelationship between Hg concentration in fillets and fish size (total body length and whole fishweight). When established, the relationships were used to predict the sizes at which criteriawere exceeded. Linear correlation analysis was performed to establish a relationship betweenlog transformed total body length and whole fish weight. Linear correlation analysis was alsoperformed on Hg concentrations in fillets; skin-off versus skin-on. This relationship was thencompared to the linear 1: 1 relationship of concentrations to evaluate whether the skin-onfillets do constitute the worst case Hg exposure.

Results

A total of 125 fish from four species were analyzed; 48 northern pike, 50 yellow perch, 17white sucker and 10 pumpkinseed. The results of the Hg analysis for the 250 fillets aresummarized in Table 1. All four species showed some detectable levels ofHg. Individualvalues ranged from less than reportable detection levels to 1.69 ug/g Hg, wet wt. in a yellowperch skin-on fillet. In general, the levels were higher in fillets from northern pike and yellowperch than in white sucker and pumpkinseed, consistent with the trophic level status of thespecies.

Exceedence of CriteriaTwenty two fillet samples derived from 13 individual fish exceeded either the ?\..mCH orUSFDA criteria for Hg, all from northern pike and yellow perch. These 13 fish were collectedfrom 6 different sampling locations, with 6 of the fish taken from Marsh Creek Pool. Two fishwith fillet samples exceeding criteria were taken from Pools Al and H, and one fish each fromPools M2, I, and C3. Nine of the 13 fish had both fillets, skin-off and skin-on, exceed one ormore criteria. All fillets from white sucker and pumpkinseed were well below the criteria.

For northern pike, seven individual fish from four different collection locations (pools AI, I,M2 and Marsh Creek) exceeded the criteria. Five skin-off fillets and seven skin-on filletsexceeded the MDCH's limited consumption criteria (0.5-1.5 ug/g Hg. wet wt.) advising onemeal per month/week (depending on the target population). No fillets exceeded the MDCH'sno consumpti<:>n category (>1.5 ug/g Hg. wet wt.). Two skin-off fillets and one skin-on filletexceeded the USFDA' s tolerance level for Hg in fish for interstate commerce (> 1. 0 ug/g Hg,wet wt.). The smallest pike to exceed the criteria measured 1077.9 g (2.4Ib) whole fish

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weight and 570 mm (22.4 in) total body length.weight and 850 mm (33.5 in) total body length.

The largest was 3593.3 g (7.9Ib) whole fish

For yellow perch, six individual fish from four different locations (Pools AI, C3, H and MarshCreek) exceeded the criteria. Five skin-off fillets and five skin-on fillets exceeded theMDCH's limited consumption criteria, while one skin-on fillet exceeded the no consumptioncriteria. Two skin-on fillets exceeded the USFDA's tolerance level for Hg. The smallestyellow perch to exceed the criteria measured 50.4 g (O.llb) whole fish weight and 160 mm(6.3 in) total body length. The largest was 165.7 g (0.4Ib) whole fish weight and 230 mm(9.1 in) total body length.

Comparison to 1988 DataAlthough the 1988 data set (Best et al. 1995) is limited by QA/QC concerns. small samplesize. and skin-off fillet data only. some comparisons in the Hg levels may be made to thepresent data set. In 1988, seven of 14 skin-off fillets from northern pike exceeded the :MDCHand USFDA criteria. with exceeding values in the range of 0.51-1.4 ug/g Hg. wet wt. (Table2). Those 7 fish ranged in size from 419-2571.2 g (0.9-5.7Ib) whole fish weight and 425-710mm (16.7-28.0 in) total body length. These seven fish were taken from two of the four poolssampled; Pools Al and M2. In general. this matches well in size. concentration and locationwith the present data set for those fish which exceed the criteria. This suggests that Hg innorthern pike fillets has remained stable from 1988 to the present time.

In 1988, none of the yellow perch skin-off fillets exceeded the MDCH or USFDA criteria forHg (Table 2). However, only four fish were collected and all four were from a single pool,Pool C3. The 1988 fish generally were of a larger size than the yellow perch which exceededthe criteria from the present study. One perch that exceeded the criteria in the present studywas from Pool C3. From this limited comparison, one might conclud.e that Hg levels inyellow perch fillets have risen from 1988 to the present time.

In 1988, only two white sucker skin-offfillets were analyzed, both from Pool Al (Table 2).While neither exceeded the :MDCH or USFDA criteria for Hg, they are nearly an order ofmagnitude higher than the levels detected in the present study. This may suggest that Hglevels in white sucker fillets have fallen from 1988 to the present time, and/or there aredifferences in Hg exposure/uptake among pools.

Relationship between Length and Weight ofFishAll four species exhibited a good linear relationship between log transformed whole fishweight and total body length (Figure la-Id). Ifone assumes that the general size ofa fish isan indicator of age, then either measure of size may be a general indicator of age. Actual agewas not determined from the scale samples. If there is a demonstrated relationship betweensize of fish and the level of Hg in fillets, then either measure of size may be used inestablishing size-related consumption advisories. However, weight is expected to vary morethan length due to variation in seasonal metabolism and incidences of feeding.

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Relationship between Bg in Fillets and Size of Fisha. Northern PikeThe northern pike samples exhibit significant positive correlations between measures of Hg infillets, skin-off and skin-on, and measures of fish size, total body length and whole fish weight(Figures 3a, 4a, 5a, 6a). Using the linear relationships for total body length, the calculatedlines exceed the MDCH Griteria for limited consumption at a fish length of 67,7.9 mm (26.7 in)for skin-off fillets (Figure 3a), and at a fish length of683.5 mm (26.9 in) for skin-on fillets(Figure 4a). A:il five skin-off fillets that exceeded the MDCH criteria also exceeded thecalculated exceedence length of677.9 mm (Figure 3a). Whereas, only five of the seven skin-on fillets that exceeded the MDCH criteria also exceeded the calculated exceedence length of683.5 mm (Figure 4a). This suggests that skin-off fillets may be more predictive ofMDCH Hgcriteria exceedence. The calculated lines did not exceed the USFDA Tolerance Level foreither fillet type within the range of total body lengths.

Similar relationships occur between Hg in fillets and whole fish weight. Using the linearrelationships for whole fish weight, the calculated lines exceed the MDCH criteria for limitedconsumption at a fish weight of 1796.0 g (3.96Ib) for skin-off fillets (Figure Sa), and at a fishweight of 1835.0 g (4.05 lb) for skin-on fillets (Figure 6a). As was the case for length, all fiveskin-off fillets that exceeded the MDCH criteria also exceeded the calculated exceedenceweight of 1796.0 g (Figure Sa). Whereas, only five of the seven skin-on fillets that exceededthe MDCH criteria also exceeded the calculated exceedence weight of 1835.0 (Figure 6a).This also supports the above suggestion that skin-off fillets may be more predictive of MDCHHg criteria exceedence. The calculated lines did not exceed the USFDA Tolerance Level foreither fillet type within the range of whole fish weights.

b. YeUow PerchFor yellow perch, no relationships could be demonstrated between Hg in either fillet type andeither measure offish size (Figure 3b, 4b, 5b, 6b). While exceedences ofHg criteria didoccur, no predictable relationship with size was evident. Contrary to expectation, those filletsthat exceeded MDCH or USFDA criteria were derived from medium to small-sized fish withinthe range of sampled sizes. For skin-off fillets, five samples exceeded only the MDCH criteriafor limited consumption (Figure 3b, 5b). Of the five skin-on fillets to exceed the MDCHcriteria for limited consumption, two also exceeded the USFDA's Tolerance Level, and oneexceeded the MDCH criteria for no consumption (Figure 4b, b).

Co White Sucker and PumpkinseedWhile both the white sucker and pumpkinseed exhibit good to significant positive correlationsbetween Hg in either fillet type and either measure of fish size (Figure 3c-3d, 4c-4d, 5c-5d,6c-6d), the levels ofHg in fillets from both species fell well below any criteria and pose littlerisk to human consumption. The relationships are stronger for the white sucker, owing in partto a larger sample size.

Relationship between Hg in Fillets, Skin-OfT versus Skin-On

6

This relationship is investigated to see if skin-off fillets represent the worst case scenario forHg exposure to humans. Presumably, with the deposition of Hg predominantly in muscletissue. the removal of the skin and subcutaneous fat should result in higher concentrations ofHg in skin-off fillet samples when compared to its paired skin-on fillet. The results show thatthe correlation between Hg in paired skin-off and skin-on fillets closely approximates an equal1: 1 ratio for all four species (Figure 2a-2d). Although not measurably different from the 1: 1relationships, the correlations do show a trend toward higher concentrations in the skin-offfillets. Ninety of the 125 paired fillet samples exhibited higher levels of Hg in skin-off filletsthan in skin-on fillets. The trend was also evident for paired fillets for each species; 34 of 48northern pike, 36 of 50 yellow perch. 14 of 17 white sucker, and 6 of 10 pumpkinseed.

Discussion

Our data supports the MDCH's special consumption advisory for Hg in fish from inland lakes.Clearly northern pike and yellow perch exceed the MDCH criteria in a consistent manner.That these two species should exceed the criteria, whereas white sucker and pumpkinseed didnot, is likely indicative of their more piscivorous food habits and more elevated trophicpositions. To have exceedences for fish from half of the sampling locations suggests that anyspecific consumption advice contemplated by the Seney NWR or mandated by the MDCHwould be appropriate for waters within the entire refuge.

For the northern pike, the significant positive correlation between Hg in fillets and fish size,would allow for the possible issuing of size-specific advice for limited consumption. Based onthe exceedence of the MDCH limited consumption criteria (0.5-1.5 ug/g Hg, wet wt.) at acalculated total body length of675-680 mm (-26.5 in), this would allow for northern pikeunder this size to be excluded from any consumption advice. Fish over this size would besubject to limited consumption; one meal per week advised for the general population, andone meal per month advised for pregnant women, nursing mothers, women who plan to havechildren, and children under 15 years of age.

An alternative to using the calculated fish size would be to use the smallest actual northernpike to exceed the MDCH criteria for limited consumption. Using this method, northern pikegreater than 570 mm total body length (22.4 in) would trigger the limited consumptionadvisory. This would be more restrictive and protective of human health. The results of eithermethod would be similar to the limited consumption advisory issued by the MDCH fornorthern pike >558.8 mm in length .(22 in) in the Manistique River outside the refuge.

For yellow perch, the situation is clouded by the lack ofa relationship between Hgconcentration in fillets and fish size, and the exceedence of the MDCH's no consumptioncriteria. While .seney NWR has in the past planted yellow perch in one or more pools on therefuge, all sources of fish have come from other refuge pools. Therefore, the fish with highHg concentrations can not be attributed to off refuge sources. No explanation is offered for

.,

the elevated Hg levels in the small to medium-sized perch. Based on these inconsistencies andthe exceedence of the no consumption criteria, it may be necessary to implement a noconsumption policy for yellow perch taken from Seney NWR. A catch and release fisherycould still occur.

For those species offish covered under the ~CH special advisory for Hg, but that were notcollected or analyzed, it may be necessary to maintain the special advisory for those speciesthat are known to occur on the refuge. This seems prudent in the absence of any data specificto these species.

There is insufficient data from the initial fish collections in 1988 to establish a trend over timefor Hg in edible fillets. However, the elevated levels ofHg found in both collections, suggestthat this issue will need to be revisited in the future with additional collections and analyses.

Recommendations

Based on the above findings, the following recommendations are offered for consideration bythe Seney NWR:

1) At the request of Seney NWR, ELFO will submit the complete data set to MDCH,Environmental Epidemiology Division for formal review and possible issuance ofconsumption advisories specific to Seney NWR. The earliest formal advice providedwould likely be available to the public in the year 2000, as provided in the MichiganFishing Guide for the period of April 1, 2000 to March 31, 2001.

2) Beginning in 2000 and continuing until the possible issuance of a formal advisory fromt..mCH, Seney NWR will issue the following interim consumption advice for all refugewaters:

a) no consumption of yellow perch,b) limited consumption of northern pike greater than 570 mm total body length (22.4

in), andc) limited consumption of rock bass, or crappie over 228.6 mm (9 in) in length, or

bass, walleye, or muskellunge of any size, if these species are known to occur inrefuge waters. (At this time, black crappie, walleye and smallmouth bass areknown to occur.)

Limited consumption is defined as one meal per week for the general population, and onemeal per month for pregnant women, nursing mothers, women who plan to have children,and children under 15 years of age.

3) Seney NW:R will initiate an outreach program to educate and alert visitors and sportfishermen to the refuge of the existing special advisory for Hg in fish statewide, the interim

8

advisory for Hg in fish specific to Seney NWR, and any formal advisory for Hg in fish tobe issued in the future by the :MDCH specific to Seney NWR.

4) Seney NWR, ELFO and Green Bay FRO will develop a monitorring protocol to quantifylevels ofHg in edible fish fillets derived from refuge pools in future years.

Acknowledgments

This study was funded in part by the On-Refuge Contaminant Investigation Program, Divisionof Refuges. U.S. Fish & Wildlife Service. Fish collections were accomplished by F. Stone andI.P. Pagel of the Ashland FRO. R. Elliott and S. Cogswell of the Green Bay FRO. and M.Tansy. G. Heet, R Urbanek, T. Papple, A. Duszynski and interns of the Seney NWR. Specialthanks goes to I. Wilson for GIS mapping, and R. Elliott and W. Bowerman for critical reviewof this manuscript.

Literature Cited

Best, D.A., T.J. Kubiak and D.E. Boellstorff. 1995. Survey of contaminants in soils andbiota at the Seney National Wildlife Refuge. U.S. Fish Wildl. Serv., East Lansing FieldOffice. 21 pp.

Monk. H.E. 1961. Recommended methods of analysis of pesticide residues in food stuffs.Report by the Joint Mercury Residue Panel. Anal. 82:608-614.

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Table 1. Mercwy (ugig, wet weight) in Fish Fillets, Skin-Off and Skin-On, 1996-97.

TotalBody

Length(mm)

Hg (ugig, wet weight)WeightWhole

Eshjg)Date

CollectedFilletSkin-OfT

FilletSkin-OnSample

Northern Pike:96-0196-0296-0396-0496-0596-0697-0197-0297-0397-0497-0597-0697-0797-0897-0997-1097-1197-1297-1397-1497-1597-1697-1797-1897-1997-2097-2197-2297-2397-2497-2597-2697-2797-2897-2997-3097=-31

~

7/18/967/18/967/18/967/17/967/17/967/17/967/22/977/22/977/22/978/18/976/05/976/13/976/05/976/04/976/05/976/04/976/04/976/04/976/04/976/04/976/05/976/04/976/05/976/05/976/04/976/04/976/11/976/06/976/1 0/976/08/976/10/976/08/976/05/976/08/976/08/976/06/976/08/97

GGGJJJ

C3C3C3AlM2

GMCMCM2MCMCMCMCC2M2C2

MCMCMCC2

IRD

DM2

DA2M2A2A2RDC2

460480375415415390405360420585605655655580645445605810850625630540525575495495545485650610565615725595545555590

439.4599.2225.4336.5383.7293.7357.8241.7387.9939.6

1294.51520.31579.71315.81595.4469.21249

3142.23593.3

13631333.61006.2762.4

1107.9690.6644.9700.6618.4

1416.81257.21077.71187.62230.6

1119670.1

8551158.1

0.2310.1850.03880.1140.1160.04720.1360.080.0690.2980.2820.1130.4080.1620.2930.220.2671.031.020.2080.2240.2220.2390.2830.3580.2670.3210.2520.320.3850.3020.1830.5730.1920.2730.4810.319

0.2030.1250.070.08110.1330.05220.1050.07210.1070.2670.2640.1860.5560.1020.2480.1790.1911.290.7840.1840.3270.1790.2480.2950.2680.2330.3480.2350.2820.3110.2980.1570.5280.1650.210.4390.269

10

Table I. continued

Hg (ugig, wet weight)Total

BodyLength

(mm)

WeightWhole

Fish (g)FilletSkin-On

FilletSkin-Off

DateCollected ~Sample

Northern Pike97-3297-3397-3497-3597-3697-3797-3897-3997-4097-4197-42

8991104.4749.9972.1

2599.3924.7

1660.31777.51077.91294.31975.7

0.3930.240.4710.1880.9120.2880.4620.4910.2430.4270.726

0.3520.2170.4070.1620.8630.2570.3550.3730.7930.4410.743

6/06/976/10/976/10/976/06/976/05/976/08/976/11/976/05/976/06/976/06/976/08/97

RDDD

RDMCAl

IMC

IRDAl

555580570570770550655650570620705

Yellow Perch96-0196-0296-0396-0496-0596-0696-0796-0896-0996-1096-1197-0197-0297-0397-0497-0597-0697-0797-0897-0997-1097-1197-1297':13

0.040.03640.04950.02560.03670.03390.02680.03810.04240.02830.0550.1920,090.1190.08110.07920 . 09730.05450.050.560.6960.7550.9360.964

0.03640.02540.04760.02910.04310.03310.03810.02750.020.02880.03540.1640.10.06670.06730.07690.07890.03961.060.540.5651.690.99

< 0.0196

11111

GGGGGG

AlAlA2A2DDHHH

MCC3Al

MC

205210240170205235240215215240275280235255245250250240225230210210210160

92.7102.4158.954.186.7

162.2152.4130.1

105166.7243.2237.3130.6

199162.2191.2193.1

190165.7159.4

113122.8114.350.4

7/17/967/17/967/17/967/17/967/17/967/18/967/18/967/18/967/18/967/18/967/18/968/18/978/18/978/19/978/19/977/23/977/23/978/18/978/18/978/18/977/24/977/22/978/18/977/24/97

Table 1 continued.

Hg (ug/g, wet weight)TotalBody

Length(mm)

WeightWhole

Fish (g)FilletSkin-OfT

FilletSkin-On

DateCollectedSample

White Sucker:97-1097-1197-1297-1397-1497-1597-1697-17

f-.Q.-Ql

8/18/978/18/978/18/978/18/977/23/978/19/977/24/977/22/97

HHHHD

A2MCC3

470395405340255215200355

1206.3766.4

830457.9187.996.8105

524.1

0.09730.0280.02940.02610.01960.02940.01830.0648

<

Pumpkinseed:97-0197-0297-0397-0497-0597-0697-0797-0897-0997-10

7/24/977/24/977/24/977/24/977/24/977/24/977/24/977/24/977/24/977/24/97

MCMCMCMCMCMCMCMCMCMC

130140130125125125115125140130

50.769.757.743.149.441.534.545.465.152.6

0.0420.0680.03810.04950.05560.03450.02940.05610.07760.09

0.1040.05770.02780.05040.03960.03960.02880.050.08410.0667

MC - Marsh Creek Pool.RD - Riverside Dike Pools along Driggs River.Total body length rounded to nearest 5 mm.Results reported to 3 significant digits.Bolded result exceeds USFDA tolerance level for Hg in fish for interstate

commerce (> 1.0 ug/g, wet wt.) and/or MDCH criteria for Hg in fish (0.5-1.5 ug/g,wet wt. for limited consumption; > 1.5 ug/g, wet wt. for no consumption).

"<" - Result < reported detection limit.

13

o.o.o.o.o.o.o.o.

08470351026103018501870171041

Table 2. Mercury (ug/g, wet weight) in Fish Fillets, Skin-Off, 1988.

Hg (uglg, wet wt.)TotalBody

Length(mm)

WeightWhole

Fish (g)FilletSkin-Off

DateCollected P-.o-.o1Sample

Northern Pike:88-3088-3288-2688-2888-4088-3888-4288-3488-3688-4688-4888-4488-5288-50

* 1.4* 0.96* 1.1

0.59* 0.44

0.53* 0.51

0.40.550.160.170.220.430.18

4/26/884/26/884/28/884/28/885/02/884/29/885/02/884/29/884/29/884/20/884/20/884/20/886/18/886/16/88

M2M2M2M2AlAlAlAlAlC3C3C3EE

710620600435665525445460425410380345560545

2571.21683.51272.3473.3

1636.7894.7520.8489.3

419388.6272.2233.3

1227.61154.6

YeUow Perch:88-5488-5888-6088-56

0.450.280.390.42

4/20/884/20/884/20/884/20/88

C3C3C3C3

300250265255

318.3243.7227.6199.5

White Sucker:88-6788-69

0.190.21

4/29/884/29/88

AlAl

400375

937.3836.3

Total body length rounded to nearest 5 mm.Results reported to 2 significant digits.Bolded result exceeds USFDA tolerance level for Hg in fish for interstate

commerce (> 1.0 ug/g, wet wt.) and/or MDCH criteria for Hg in fish (0.5-1.5 ug/g,wet wt. for limited consumption; >1.5 ug/g, wet wt. for no consumption).

"." - Result is actual result from PACF; all other results are estimates using correction

factor (1.48) derived from mean of the ratio of results (P ACF:contract laboratory).Data from Best, D.A., T.J. Kubiak and D.E. Boellstorff. 1995. SurVey of contaminants

in soils and biota at the Seney National Wildlife Refuge. U.S. Fish Wildl. Serv.,East Lansing Field Office. 21 pp.

14

z

'"

~5'~

d

<1<0iiif

J

;I

..'

£

r'~~~,,""'

f ~~!;fC

~

LJI:Zoo~v 1'I

:

~

f-[8'2-

(

iI

ig{(J

J

~

Figure 2. Relationship between log Total Body Lengdt (mm) and log Whole Fish Weight (g).

Soild symbols are not data points.


16

Figure 2. continued.

Soild symbols arc not data points.


11

Figure 3. Relationship between Total Body Length (mm) and Hg in Fillets, Skin-Off (ug/g, wet wt.).

Fig. 3a. Northern Pike (y = 0.0017 x - 0.62 r-squared = 0.65 P < 0.001 n = 48)

Northern Pike

Length vs. Hg in Fillets, Skin-Off


TL - tolerance level, LC - limited consumption.

Fig.3b. Yellow Perch

Yellow PerchLength vs. Hg in Fillets, Skin.Qff

TL - tolerance level. LC - limited consumption.

18


Fig.3c. White Sucker (y = 0.00022 x - 0.035 r-squared = 0.41 P < 0.01 n = 17)

White SuckerLength vs. Hg in Fillets, Skin-Off

~

<>

<>

0

~<;0<>

~Q~.

~~

0

0

.--

100 200 300 400Total Body Length (rom)

500 600


Fig. 3d. Pwnpkinseed (y=0.OOI7x-0.16 r-squared=0.41 P<O.OS n= 10)

PumpkinseedLength vs. Hg in Fillets, Skin-Off

0

<>

<>

~~~

~

;0:~~0~

- 0.1

iJcD 0.08

"'Cb..:.

~] 0.06

cn

!ifi= 0.04~.$bO~ 0.02

110 120 140 150130Total Body Length (mrn)


19

Figure 4. Relationship between Total Body Length (rom) and Hg in Fillets. Skin-On (ug/g. wet wt.).

Fig. 4a. Northern Pike (y = 0.0016 x - 0.63 r-squared = 0.55 P < 0.001 n = 48)

Northern PikeLength Y5. Hg in Fillets, Skin-On

1000

Soild symbols arc oot data points.NC - 00 COOaIJD~ TL - toIeranco level, LC - limited coosumptioo.

Fig. 4b. Yellow Perch

Yellow PerchLength vs. Hg in Fillets, Skin-On

NC - 00 ~ptioo, TL - ~ ~l. LC - limited consumption.

20

Fig. 4c. White Sucker (y - 0.00020 x - 0.037 r-squared = 0.47 P < 0.01 D - 17 )

White SuckerLengili vs. Hg in Fillets, Skin-On


Fig.4d. Pwnpkinseed (y=0.OOI8x-0.18 r-squared=0.31 P<0.10 0-10)

PumpkinseedLength vs. Hg in Fillets, Skin-On

150110 120 130T ota1 Body Len 8th (nun)

Soild symbols arc not data points.

21

).02

01

-00

Figure 5. Relationship between Whole Fish Weight (g) and Hg in Fillets, Skin-Off(ug/g, wet wt.).

Fig. 5a. Northern Pike (y = 0.00027 x + 0.015 I-squared = 0.73 P < 0.001 n = 48)

Northern Pike

Weight vs. Hg in Fillets, Skin-Off

1.2

1

0.8

0.6

-~J~-=-ftj

VJ

~--ii:.sco

:I:

s 42Whole Fish Weight (g)

0 ..

Soild symbols are not data points.TL - tolerance level, LC -limited consumption.

Fig. 5b. YeUow Perch

Yellow PerchWeight vs. Hg in Fillets, Skin-Off

TL - tolerance level, LC - limited consumption.

22

0.4

0.2

0


Fig.5c. White Sucker (y=O.OOOO48x+O.Ol0 r-squared=O.40 P<O.OI 0=17)

White SuckerWeight vs. Hg in Fillets, Skin-Off


Fig. Sd. Pumpkinseed (y = 0.0011 x - 0.0020 r-squared = 0.37 P < 0.10 n = 10)

PumpkinseedWeight vs. Hg in Fillets, Skin-Off


23

Figure 6. Relationship between Whole Fish Weight (g) and Hg in Fillets, ~kin-On (ug/g, wet \\1.).

Fig.6a. Northern Pike (y = 0.00027 x + 0.010 r-squared = 0.61 P < 0.001 n = 48)

Northern PikeWeight vs. Hg in Fillets, Skin-On

~ 1.5.~~~ 1.,:,

0.5!.;js~.500

:I: 00 1 2

Whole Fish Weight (g)3 4

Soild symbols are not data points.NC - no consumption, TL - tolerance level, LC - limited consumption.

Fig. 6b. Yellow Perch

Yellow PerchWeight vs. Hg in Fillets, Skin-On

NC - no consumption, TL - tolerance level, LC - limited consumption.

24

Figure 6. continued

Fig. 6c. White Sucker (y = 0.000045 x + 0.0046 r-squared = 0.46 P < 0.01 n - 17)

White SuckerWeight vs. Hg in Fillets. Skin-On

0<>

0.

~~ <>~

~

~000

~<' 9 <>0.

~~

;,-~-"'-~150010000 500

Whole Fish Weight (g)

SoiId symtK>IJ are not data points.

Fig. 6d. Pumpkinseed (y=0.00091 x+O.OO9O r-squalai-0.16 P<0.20 0-10)

PwnpkinseedWeight vs. Hg in Fillets, Skin-On

(>

<>

~~<>

~~~

~-er-.~~~.- O!

.0. 0-

0.06

0.04

0.02807050 60

Whole Fish Weight (g)4030

SoiId symbols are not data points.

2S

0.12

0.1

0.08

Figure 7. Relationship between Hg in Fillets. Skin-Otr and Hg in Fillets. Skin-On (ugtg. wet wt.).

Fig. 78. Northern Pike (y = 0.96 x + 0.0031 r-squared = 0.80 P> 0.001 n = 48)

Northern Pike

Skin-Offvs. Skin-On

,-..

ii

.;;-=-

Soild symOOls arc not data points.

Fig. 7b. Yellow Perch (y ~ 0.89 x + 0.024 r-squared = 0.43 P < 0.001 n - 50)

Yellow PerchSkin-Off vs. Skin-On

2

Q

'""'

i

IcO 1.5

~

10 .

fn

j:= 0.5~.S~:c 0

0 0.2 0.4 0.6 0.8 1;2. Hg in Fillets, Skin.Off (ug/g. wet wt)

-SoiId symbols aR not data JK>ints

26


Fig.7c. White Sucker (y = 0.80 x + 0.0011 r-squared = 0.87 P < 0.001 n = 17)

White SuckerSkin-Offvs. Skin-On

Fig.7d. Pumpkinseed (y = 0.55 x + 0.025 r-squared = 0.20 P < 0.20 n = 10)

PumpkinseedSkin-Off Ys. Skin-On

- 0.12ij 0.1~..=.~ 0.08

]CI) 0.06 I

ifs~ 0.04.S~

:x:0.02

0.02 0.08 0.10.04 0.06Hg in Fillets, Skin-Off (ug/g. wet wt.)


27

David A. Best - FWS

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