1. Biomagnification of Monomethylmercury in Carnegie Lake x 10 4 H2OH2O

2. Are there differences in MMHg uptake for different species of phytoplankton? Which characteristics might be related to increased uptake?

3. Size Fractioning Target GroupFilter pore size Phytoplankton and particulates0.4−20 μm Herbivorous zooplankton>20 μm Target GroupSignal Live AutotrophsDNA & chlorophyll Live HeterotrophsDNA DetritusNone Flow Cytometry

4. Within each site: Does the concentration of MMHg increase with increasing trophic level? ClamsAmphipodsBlood wormsSnails

5. Comparing the 5 sites: Is there a correlation between the density of phytoplankton and the concentration of mercury in the biota? Phytoplankton density based on fluorescence of chlorophyll (mg of chlorophyll L -1 )

6. High Plankton Densities Reduce Mercury Biomagnification Chen & Folt, 2005

8. Question: Is there a correlation between the density of phytoplankton and the concentration of MMHg in the biota?

9. CONTAMINATED FILTER

12. Mean Mercury Concentrations in Freshwater Fish Species Mean concentration (ppb) Bottom Feeders Carp110 White sucker 110 Channel catfish 90 Predator Fish Largemouth bass 460 Smallmouth bass 340 Walleye 520 Brown trout 140 a EPA National Study of Chemical Residues in Fish 1987; b Concentrations are reported on wet weight basis Source: Bahnick et al., 1994. 705.6 ppb HgT 312.4 ppb HgT

13. X 20,000 X 2 X 8 Biomagnification of Total Mercury

14. Thanks to PEI, Dr. Eileen Zerba, Dr. Francois Morel, Frank Black, Nejma Piagentini, and my fellow interns for all your help this summer!