An Investigation of the Links Between Microbial Sulfate Reduction and Hydrocarbons: Implications for Anoxia Development in the Northern Gulf of Mexico

Previous assessments concerning the development of anoxia (severe oxygen deficiency) in Louisiana shelf waters have assumed that the only reduced carbon source for sulfate-reducing bacteria is plankton blooms and have overlooked natural hydrocarbon seepage from deep-seated reservoirs (seeps). To confirm that sulfate-reducing bacteria can mineralize hydrocarbons in both liquid (crude oil) and gas (methane) forms and to assess the effects of types of hydrocarbons on the intensity of sulfate reduction, the researchers will calculate the rates of microbial sulfate reduction depending on the type of hydrocarbon substrate. The hydrocarbon samples used will be taken from offshore seeps where there is clear segregation between types of hydrocarbons, and shallow-water plankton blooms have no influence. The results of this study will provide a baseline for evaluating the causes of anoxia in Louisiana shelf waters.