Student Research Projects
Mercury Bioaccumulation in Freshwater Fishes
Methylation of mercury occurs when the inorganic form is converted to the organic form via microbial sulfate reduction within the aquatic sediments (Gilmour et al., 2002). This a concern to human health it is recommended that fishes exceeding 1 p.p.m. should not be consumed (FDA, 2008). Fish become contaminated through the means of bioaccumulation of mercury through the trophic levels of the aquatic ecosystem. Upon methylation mercury is taken up by phytoplankton and subsequently zooplankton. Fishes consume the zooplankton thus the concentration of mercury increases as the trophic level increases. Therefore predator fishes should contain higher concentrations of mercury than prey fishes. In addition, bottom dwelling fishes are subject to elevated levels of mercury due to inadvertently consuming mercury rich sediments (Coelho et al., 2008). In this study the concentrations of mercury was quantified in predator, prey, and bottom dwelling fishes from the Northwest River in Chesapeake, Virginia in order to illustrate the bioaccumulation of mercury with increase of trophic levels.