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Methylmercury in Freshwater Fish, 2020 Comparison Study

Publication number Date Published
23-03-011July 2023
VIEW NOW Methylmercury in Freshwater Fish, 2020 Comparison Study (Number of pages: 41) (Publication Size: 4541KB)

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Author(s) Foster, K., and C. Mathieu
Description In 2020, the Washington State Department of Ecology (Ecology) analyzed total mercury and methylmercury in 40 freshwater fish fillet samples collected from four lakes to characterize percent methylmercury content. Species included largemouth bass (Liberty Lake, Loon Lake, Silver Lake) and smallmouth bass (Lake Spokane). Methylmercury results were compared to total mercury concentrations measured in the paired samples, and relationships with fish growth characteristics were evaluated.

Total mercury and methylmercury were present in all tissue samples. The average percent methylmercury level was 66% (±16%), which is lower than the 95% conservative estimate referenced by the U.S. Environmental Protection Agency (EPA) in their guidance for state fish contaminant monitoring programs. Overall, percent methylmercury, total mercury concentrations, and methylmercury concentrations varied widely across bass size, age, and location.
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Keywords fish tissue, mercury, methylmercury, Largemouth bass, smallmouth bass
WEB PAGE Mercury in fish tissue
WATERSHED Water Resource Inventory Areas
(WRIA 26,WRIA 57,WRIA 54,WRIA 59)
DATA Environmental Information Management (EIM) #HgFish20


Quality Assurance Project Plan: Measuring Mercury Trends in Freshwater Fish in Washington State