Student Research Projects

Mercury Concentrations in Dolphins Stranded Along the Coast of Virginia  

Student Erin Smith ‘14
Faculty Mentor(s)
Department Earth and Environmental Sciences
Course Earth and Environmen: Research Methods in the Natural Sciences


This study was conducted to assess the mercury levels in bottlenose dolphins from North Atlantic communities. Mercury, released from both anthropogenic and natural processes, is a highly toxic metal that enters the ocean through run-off and atmospheric deposition. In sediments and ocean waters, it is converted to the form methylmercury, which more readily enters the food chain. Methylmercury is assimilated up the marine food web and bioaccumulates in the tissues of top predators, including dolphins. As a result, tissue concentrations of dolphins from Atlantic communities can be used an as indicator of relative mercury concentrations throughout their corresponding food webs. Tissues were sampled from organisms collected by the Stranding Response Team of the Virginia Aquarium. These dolphins had stranded between June 2009 and April 2013 along the Virginia coast. Samples were freeze-dried and then analyzed for total mercury using a DMA-80 direct mercury analyzer. Liver tissue samples were found to contain the highest levels of mercury, followed by the kidney tissue samples. The lowest concentrations were found in skin and muscle tissues samples. My concentration results were within the typical range found in similar studies.