Master of Science (MS)
Oceanography and Coastal Sciences
Increased demand for new sources of oil and gas has resulted in an expansion of drilling into deeper waters. With this exploratory drilling come increased risks, which were realized on April 20, 2010 when the blow out preventer on the Macondo Well failed, resulting in the release of a large quantity of oil and gas into the Northern Gulf of Mexico from a bathypelagic source. This unprecedented environmental disaster was coined the Deepwater Horizon Oil Spill by the popular news media. In the months that followed the spill, the lack of knowledge about the pre-spill condition of deep-sea communities in this area of the Gulf of Mexico became apparent. This made it difficult to determine the effects of the spill on deep-water megafauna. The objective of this study was to characterize the epibenthic and demersal megafaunal community immediately following and one year after the spill. Remotely operated vehicles conducted a series of video surveys over an extended time series (11 surveys Aug 4 – Nov 1, 2010) of a site located 750 m to the Southwest of the Macondo Well and at five additional study sites during August and September 2010: 2000m north, west, south, and east, and 500m north of the Macondo well. The 750 m Southwest site was revisited in July of 2011 to determine what, if any, changes had occurred in the deep-water megafaunal community. These study sites were dominated by demersal fishes and mobile benthic invertebrates both in 2010 and 2011. The results indicate both diversity and densities of organisms declined over time in 2010, while densities appeared to increase in 2011 to levels similar to those observed immediately following the spill. The presence of carcasses of pyrosomes, salps, and crabs in 2010 indicated some short-term or acute mortality following the spill. It is hoped that these data will be used as a post-spill baseline against which future surveys of diversity and abundance of deep-water megafauna can be compared.
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Valentine, Marla Maxine, "Characterization of Epibenthic and Demersal Megafauan at Mississippi Canyon 252 Following the Deepwater Horizon Oil Spill" (2013). LSU Master's Theses. 2869.