Abstract Title

Session S-04B: Water Quality I

Keywords

Toxics

Start Date

1-5-2014 8:30 AM

End Date

1-5-2014 10:00 AM

Description

Mercury is a contaminant of concern in aquatic organisms world-wide. These biota are exposed to mercury from both natural emissions and human-caused sources. The Washington Department of Ecology has implemented a Chemical Action Plan (CAP) campaign to virtually eliminate the human-caused sources of mercury in Washington. The Washington Department of Fish and Wildlife’s Puget Sound Ecosystem Monitoring Program (PSEMP) - Toxics in Biota team has assessed the geographic extent and magnitude of mercury and other chemical contaminants in 18 fish and macroinvertebrates species across Puget Sound since 1989. In this report we compare total mercury concentrations in over 2000 samples from multiple fish and macroinvertebrate species to evaluate where in the food web mercury may be elevated, and which life history characteristics are associated with elevated body burdens. Characteristics we tested included age, trophic level, tissue lipid content, gender and proximity to known mercury sources (i.e., urbanized locations or elevated sediment mercury concentration). The highest mercury concentrations (greater than 0.50 mg/kg, wet wt.) occurred in sixgill sharks (Hexanchus griseus) an apex predator, and long-lived rockfishes (Sebastes spp.), especially in urban locations. Mean mercury concentrations were less than 0.17 mg/kg, wet wt. for all other species, but also varied with age and proximity to contaminant source. For example, most of the variability in muscle mercury concentrations of English sole (Parophrys vetulus) was explained by age and sediment mercury concentration. We also compared the concentration of mono-methyl mercury to total mercury for a subset of 220 samples, representing a range of species and tissues. Overall the majority of mercury (>90%) was methylated, though there were notable exceptions. These data provide a solid basis for understanding the factors influencing mercury accumulation in the Puget Sound food web and serve as baseline data to evaluate the effectiveness of the Washington’s mercury CAP.

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May 1st, 8:30 AM May 1st, 10:00 AM

Mercury in the Puget Sound food web: factors influencing body burdens in multiple species.

Room 608-609

Mercury is a contaminant of concern in aquatic organisms world-wide. These biota are exposed to mercury from both natural emissions and human-caused sources. The Washington Department of Ecology has implemented a Chemical Action Plan (CAP) campaign to virtually eliminate the human-caused sources of mercury in Washington. The Washington Department of Fish and Wildlife’s Puget Sound Ecosystem Monitoring Program (PSEMP) - Toxics in Biota team has assessed the geographic extent and magnitude of mercury and other chemical contaminants in 18 fish and macroinvertebrates species across Puget Sound since 1989. In this report we compare total mercury concentrations in over 2000 samples from multiple fish and macroinvertebrate species to evaluate where in the food web mercury may be elevated, and which life history characteristics are associated with elevated body burdens. Characteristics we tested included age, trophic level, tissue lipid content, gender and proximity to known mercury sources (i.e., urbanized locations or elevated sediment mercury concentration). The highest mercury concentrations (greater than 0.50 mg/kg, wet wt.) occurred in sixgill sharks (Hexanchus griseus) an apex predator, and long-lived rockfishes (Sebastes spp.), especially in urban locations. Mean mercury concentrations were less than 0.17 mg/kg, wet wt. for all other species, but also varied with age and proximity to contaminant source. For example, most of the variability in muscle mercury concentrations of English sole (Parophrys vetulus) was explained by age and sediment mercury concentration. We also compared the concentration of mono-methyl mercury to total mercury for a subset of 220 samples, representing a range of species and tissues. Overall the majority of mercury (>90%) was methylated, though there were notable exceptions. These data provide a solid basis for understanding the factors influencing mercury accumulation in the Puget Sound food web and serve as baseline data to evaluate the effectiveness of the Washington’s mercury CAP.