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Lake Chelan Fish Tissue Monitoring: 2010 Results for Lake Chelan Water Quality Committee January 5, 2012 Keith Seiders, Toxics Studies Unit Environmental Assessment Program. Summary: Context… Monitoring Goals… Methods … Results and Comparisons
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Lake Chelan Fish Tissue Monitoring: 2010 Results for Lake Chelan Water Quality Committee January 5, 2012Keith Seiders, Toxics Studies UnitEnvironmental Assessment Program
Summary: Context… Monitoring Goals… Methods… Results and Comparisons 2010 vs 2003 - Fish Size, DDT Skin-on vs Skin-off preparation method Other Contaminants Conclusions
Washington State Toxics Monitoring Program GoalsExploratory monitoring: since 2001. Characterize toxic contaminants at sites that lack data.Long Term monitoring: begin in 2009.Track contaminant levels over time at selected sites.Cooperative/complementary efforts; address new concerns.
Goals of WSTMP 2010 sample effort • Focus on Long Term Monitoring component • Lake Chelan, Wenatchee River, Banks Lake • Compare results: Historical vs 2010 • Compare prep method: skin-on vs skin-off • Improve characterization of toxics in tissue • Support DOH data needs for review of FCA • Involve others: local gov’t, citizens, guides
Lake Chelan: 2010 effort • Mimic 2003 effort to collect/analyze lake trout • Time and location: 5/17/03 and 6/3/10 in Wapato Basin • Collection: H/L (derby in 2003, local guides in 2010) • Fish size: match weight range used in 2003 composites • Preparation: skin-on fillets both years (2010 add skin-off) • Lab Analyses DDT: EPA 8081 at MEL in 2003 and 2010 • Lab Used: MEL; EPA-2003; ECY-2010
Results • DDT levels: 2010 and 2003 • Compare skin-on vs skin-off preparation • Levels of other contaminants • Fish Consumption Advice
Summary of Two-Sample t-Tests for t-DDT in Samples from 2003 and 2010.
Total DDT levels in lake trout from 2010 remain high. • DDT levels are higher than those in 2003.
Summary of Paired-Sample t-Test for Skin-On and Skin-Off Samples.
Different fish preparation methods (skin-on vs skin-off) showed little or no difference in tissue DDT levels.
Conclusions • Total DDT levels in lake trout from 2010 remain high. Levels are higher than they were in 2003. • Different fish preparation methods (skin-on vs skin-off) showed little or no difference in tissue DDT levels. • Lake trout also have high levels of PBDE flame retardants, dioxins/furans, and elevated levels of PCBs. • Lake trout in Lake Chelan tend to be good biomagnifiers of environmental pollutants because they are: large, long-lived, fatty, and are at top of food web.
Contacts and Websites • Ecology - Fish Tissue Monitoring: Keith Seiders, 360-407-6689, Keith.Seiders@ecy.wa.gov. • Health – Fish Consumption Advice: Dave McBride, 360-236-3176, Dave.Mcbride@doh.wa.gov • Ecology Web site Toxic Hazards: http://www.ecy.wa.gov/toxhaz.html • Health Web site - Environmental Health: http://www.doh.wa.gov/ehp/oehas/fish/
Lab Method Differences between 2003 and 2010 • Lipids: different sample prep (extraction solvents). Results not comparable. • Dioxins/furans: similar yet different methods. Results comparable for this study. • Mercury: different sample prep (rigor of digestion). Comparability of results good for most purposes when conversion factor used for estimations.