Theses and Dissertations

Issuing Body

Mississippi State University


McNeal, Karen S.

Committee Member

Mylroie, John E.

Committee Member

Grimes, Craig

Date of Degree


Document Type

Graduate Thesis - Open Access


Methylmercury (MeHg) production is magnified in the natural environment by geochemical influxes and an active sulfate reducing bacteria community. It has been found that the presence of sulfides, excess nutrients, and the type of depositional environment (normal marine or euxinic) greatly influences MeHg production and degree of pyritization (DOP). The aim of this research is to investigate a possible connection between MeHg accumulation and the DOP in Weeks Bay sediment. Collected sediment samples have confirmed a significant presence of total reduced sulfides, inorganic mercury, reactive iron, and total organic carbon. Pyritization results indicate a normal marine environment and, of the three measured elements (S, Fe, and C,) carbon and sulfur are the dominant limiting factors to the DOP in Weeks Bay. Current geochemical and pH/redox conditions favor MeHg and pyrite production. The quantified pyrite greatly exceeds that of MeHg indicating DOP inhibits MeHg precipitation.