Science Serving Maryland's Coasts

Jenna Lynn Gustafsson, University of Minnesota

Class Year: 

Project Title: 

Factors Contributing to the Methylation of Mercury in Maryland Reservoirs


Emitted through natural and anthropogenic sources, the impact of mercury on human health has drawn increased awareness in recent years. Methylmercury, one of three mercury species, acts as a neurotoxin that is able to bioaccumulate through all levels of the food chain and may lead to neurological damage, fatalities, or brain damage in humans. Sulfate reducing bacteria (SRB) are considered the organisms mainly responsible for mercury methylation. However, factors such as dissolved organic carbon (DOC), pH, total mercury concentration, mercury complexation and sulfate and chloride anions are thought to control the availability of mercury to SRBs. This study will focus on answering the following questions: Are there significant differences in pH, DOC, total mercury, sulfate or chloride anion concentration between Lake Lariat and Liberty, or Clopper lakes, and can these explain the differences in fish concentration? and Do the measured parameters help explain the concentration of methylmercury in Lake Lariat at two different snapshots in time? Water and sediment samples were collected and analyzed for the presence of methyl and total mercury. The role of anions and DOC were also determined for each reservoir.