Publication Date


Document Type


Committee Members

Mark Sandheinrich (Committee Member), David Dominic (Committee Member), Chad Hammerschmidt (Advisor), Bruce Monson (Committee Member)

Degree Name

Master of Science (MS)


Monomethylmercury (MMHg) can accumulate in fish to concentrations that pose a threat to the health of fish, piscivorous organisms, and humans who eat fish. A variety of environmental factors have been hypothesized to influence either the methylation of inorganic Hg or the bioaccumulation and magnification of MMHg. This study investigates the influence of selected environmental factors on MMHg concentrations in freshwater fish across a regional scale, most of the U.S. portion of Laurentian Great Lakes region. Fish MMHg was correlated with proton deposition, sulfate deposition, nitrate deposition, mercury deposition, pH, watershed area, and Secchi depth. Only proton deposition was positively correlated with MMHg concentrations in walleye, largemouth bass, and northern pike, underscoring the fundamental role played by protons in fish MMHg accumulation in the Great Lakes region. Lake water pH showed a significant correlation with fish MMHg only in Largemouth bass, suggesting proton deposition plays a role in Hg transport.

Page Count


Department or Program

Department of Earth and Environmental Sciences

Year Degree Awarded