Publication Summary

During 2007, the exploratory monitoring component of the Washington State Toxics Monitoring Program analyzed 35 fish tissue samples representing 12 species of fish from 16 freshwater sites in Washington. Contaminants frequently detected were mercury, PBDE flame retardants, PCBs, dioxins and furans, and some chlorinated pesticides.

Contaminant levels in 10 samples from 6 sites did not meet Washington's water quality standards. Contaminants higher than standards were PCBs, 2378-TCDD, hexachlorobenzene, and mercury.

Recommendations include (1) add 6 sites to the Clean Water Act Section 303(d) list, and (2) evaluate results to assess risks to human health from the consumption of contaminated fish.

Results of freshwater fish tissue sampling conducted in 2007 as part of the Washington State Toxics Monitoring Program (WSTMP) are reported. The "exploratory" monitoring component is a screening-level effort which targets areas across Washington where historical data are lacking. Results are used primarily to identify areas of concern for follow-up actions. Because the program is not designed to assess trends, caution should be used in comparing results from year to year.

Sixteen sites across Washington State representing 12 resident freshwater species of fish were sampled in 2007. Contaminants assessed include persistent, bioaccumulative, and toxic chemicals (PBTs) such as mercury, PCBs, dioxins and furans, chlorinated pesticides, and PBDE flame retardants.

Most sample results were within the lower range of values found in other studies of fish tissue in Washington. Mercury was detected in 100%, PBDEs in 97%, and PCBs in 91% of the 35 samples analyzed. Pesticides in the DDT and chlordane groups were detected in 63% and 6% of the 35 samples, respectively.

Twenty-eight percent of all samples did not meet Washington State water quality standards for contaminants in fish tissue. Total PCBs and 2,3,7,8-TCDD accounted for most of these exceedances. Other contaminants exceeding water quality standards were mercury and hexachlorobenzene.

This study recommends that five lakes and one river be added to the federal Clean Water Act Section 303(d) List for Washington State. These sites are: Ozette, Samish, Big, Campbell, and Sullivan Lakes, and the Samish River. Samples collected from the other ten sites met Washington State water quality standards.

Link to EIM data for User Study ID WSTMP07