Student Research Projects

Mercury concentrations in the liver, kidney, and brain from bottlenose dolphins (Turnips truncates) stranded along the coast of Virginia

Student Matt Cooke, '16
Faculty Mentor(s)
Department Earth and Environmental Sciences
Course EES 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. In an original study designed to assess mercury levels in dolphins stranded in Virginia, tissues were obtained from 76 dolphins (Tursiops truncatus) that had been recovered and necropsied by the Virginia Aquarium Stranding Response Program from 2009-2014. Preliminary results indicate that tissues of longer length dolphins had higher mercury levels. There were no notable concentration differences between male and female dolphins of similar length. Liver samples were found to contain the highest levels of mercury, followed by the kidney samples. Lower concentrations were found in skin, muscle, cerebrum and cerebellum. Thirteen individuals had liver concentrations greater than the observed effect level for liver abnormalities seen by Rawson et al. (1993), which suggests that mercury may have impacted liver function in these animals. Mercury levels in this population will be compared to published studies from Florida and Israel in order to evaluate the relative exposure of the different populations. 

Conferences

SEAMMAMS March 27-29