Student Research Projects

Mercury Concentrations in the Liver, Kidney, and Brain of Bottlenose Dolphins (Tursiops truncatus) Stranded Along the Coast of Virginia

Student Sherie Coleman, '16
Faculty Mentor(s)
Department Earth and Environmental Sciences
Course Earth and Environmental Science 489: Research in the Natural Sciences

Abstract

Mercury is a highly toxic metal that enters the ocean through runoff and atmospheric deposition. In water and sediments, it can be converted by bacteria to methylmercury, which may then bioaccumulate through aquatic food webs (Fig. 1). In an original study designed to assess mercury levels in dolphins stranded in Virginia, tissues were obtained from 80 dolphins that had been recovered and necropsied by Virginia Aquarium Stranding Response from 2009-2015. Preliminary results indicate that tissue of longer dolphins had higher mercury levels and there are no notable concentration differences between male and females of similar length. Mercury levels in this population were compared to published studies from Florida and Israel to evaluate the relative exposure of the different populations (Fig. 2). Fourteen individuals had liver concentrations greater than 61 ï-g/g, the observed effect level for liver abnormalities seen by Rawson et al. (1993), which suggests mercury may have impacted liver function in these animals.