Freshwater Fish Contaminant Monitoring Program, 2012 Results

The report, Freshwater Fish Contaminant Monitoring Program, 2012 Results, is available at https://fortress.wa.gov/ecy/publications/SummaryPages/1403020.html.

Results from the Freshwater Fish Contaminant Monitoring Program in 2012 are summarized for three areas in Washington: the Spokane River, Pend Oreille River, and the North Cascades National Park.  The sampling goals were to: (1) characterize contaminant levels in fish, and (2) determine spatial and temporal patterns in contaminant levels in Spokane River fish.

Results from the Spokane River showed that levels of PCBs and PBDEs in fish remain elevated compared to most areas in Washington.  Differences in PCBs and PBDEs among Spokane River sites were found for about half of the 21 site-species pairings examined.  Concentrations of PBDEs in mountain whitefish from the Ninemile reach were approximately 4 to 10 times higher than in fish from other sites in the river.  In some cases, concentrations found in 2012 appear to be lower than those in 2005.  For PCBs, 2 of 11 cases show a decrease, with both cases occurring in the Mission Park reach.  For PBDEs, 5 of 11 cases show a decrease.

Levels of mercury, PCBs, and dioxins in fish from the Pend Oreille River fall in the 40-80th percentile range of levels found in fish throughout Washington.

Contaminant levels in fish from the North Cascades National Park were relatively low for all analytes, except for 4,4’-DDE in kokanee that had returned to the Stehekin River from Lake Chelan.  Contamination of Lake Chelan with 4,4’-DDE is well known and is the focus of a water cleanup plan.

Washington’s water quality standards for contaminants in fish tissue, expressed as Fish Tissue Equivalent Concentrations (FTECs), were met for most of the chemicals analyzed.  However, most samples failed to meet FTECs for PCBs.  Several samples of mountain whitefish from the Spokane River did not meet FTECs for dioxins.  One sample of kokanee from the Stehekin River did not meet the FTEC for 4,4’-DDE.

If you have questions, contact Keith Seiders at 360-407-6689 or keith.seiders@ecy.wa.gov.