CHED 255 |
| Mercury is an environmental toxin which has been a historic problem in the San Francisco Bay and Delta. Mercury bioaccumulates and biomagnifies, and in high concentrations, has detrimental effects on the growth, reproduction, development, and behavior of humans and wildlife. Currently, we are working in cooperation with San Francisco Estuary Institute (SFEI) to assess mercury levels in small fish in the SF Bay. SFEI's project goals include characterization of food web mercury at finer spatial and temporal scales and the detection of regional bioaccumulation trends related to wetland restoration. Our goal within this project is to analyze the mercury burden in individual small fish obtained from sampling locations within the SF estuary. Specimens were obtained from the following locations: China Camp, Benicia Park, and Angel Island. Species consisted of one pelagic, the Mississippi Silverside, and 3 deep water species, the Shimofuri Goby, Yellow Goby, and Bay Goby. All samples were lyophilized and homogenized. Samples were digested with sulfuric and nitric acid and oxidized with potassium permanganate and potassium persulfate, following EPA protocol 245.6. Total mercury was determined via CVAA-GA. Preliminary results suggest that Mississippi Silversides are highest in total mercury content, followed by Shimofuri Gobies. Yellow Gobies and Bay Gobies both show very low concentrations. Currently research is underway to increase sample size and expand geographic coverage. 13C/12C and 15N/14N isotopic ratios will be measured to assess the significance of foodweb interactions with respect to the observed trends. More definitive conclusions are expected later this year as to the relationship between total mercury concentration and fish species, habitat, and geographic location. |
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Undergraduate Research Poster Session: Environmental Chemistry
2:30 PM-4:30 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Poster
Division of Chemical Education |