With funding through this Grant for Rapid Response Research (RAPID), researchers at the University of Southern Mississippi will examine the Deepwater Horizon oil spill in the northern Gulf of Mexico -- an oil spill of national significance -- to study the fate, transport and transformation of crude oil components and their interactions with marine organic matter from baseline to maximum impact in a complete time series. Their working hypothesis is that the crude oil components are isotopically light (in terms of carbon-13) and distinct in optical properties (UV-vis and fluorescence emission-excitation matrices [EEM]) from natural marine organic matter, thus allowing the use of stable isotopes and fluorescence techniques for quantitative understanding of their fate, transport, and transformations in the northern Gulf of Mexico. They will collect seawater samples at a station in the Mississippi Bight in the northern Gulf of Mexico from base line conditions to maximum impact. EEM fluorescence, stable isotopes, and flow field-flow fractionation techniques will be employed. Measurements will include dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and particulate organic carbon (POC) and their stable carbon isotopic composition (C-13), optical properties, including UV-vis absorbance, adsorption coefficient, spectral slope, and EEMs, composition and size spectrum of DOM, chlorophyll-a, and other common environmental parameters, such as salinity, temperature, dissolved oxygen, and nutrients. Results of this study are expected to provide new insights into how organic matter from oil spills interacts with marine organic matter affecting the ocean carbon budget, biogeochemical processes, and marine ecosystems as a whole.
Broader Impacts Combined with planned and ongoing research in response to this unprecedented oil spill in the northern Gulf of Mexico, this research will contribute to the understanding of the fate, transport and transformation of spilled oils and their interactions with natural marine organic matter in the water column in the coastal environment. The investigators will collaborate with other funded projects for data sharing. The project will support one graduate student, who will gain valuable experience in rapid response research as well as in interacting with other research teams in the Gulf Coast region.
