Factors Controlling Macondo Oil Biodegradation on a Rapidly Eroding Coastal Headlands Beach

• Main Author: Urbano, Marilany G.
• Other Authors: Hall, Steven G.
• Format: Others
• Language: en
• Published: LSU 2012
• Subjects: Civil & Environmental Engineering
• Online Access: http://etd.lsu.edu/docs/available/etd-04262012-095714/

Fourchon Beach, located along the southeast Louisiana coast, was affected by the oil leaking from the British Petroleums Deepwater Horizon Oil rig explosion in 2010. The oil, labeled MC252 oil, came ashore in a stable emulsion form, contaminating the sand, salt pan, marsh and mangroves along the beach. A unique oil form, labeled SSRB (small surface residue ball) was formed from the MC252 oil and a combination of environmental factors. The SSRB is an aggregate of sand and emulsified oil, and forms a large portion of the oil still present on the supratidal zone of Fourchon Beach. SSRBs have not been properly studied and their fate is largely unknown. For this research, various experiments were conducted to examine the biodegradability potential of SSRBs. First, an assessment of the subenvironments where the SSRBs were located was conducted. The environments appeared unfavorable for biodegradation to occur, with low organic matter and high salinities. Then, a characterization of the SSRBs physical and biochemical conditions was performed. Results indicated that their characteristics were closely dependent on the subenvironments in which they were located. Nonetheless; certain features pointing towards biodegradation were also found: microorganisms capable of degrading oil hydrocarbons and sources of nutrients and electron acceptors. Also, n-alkanes were substantially depleted in SSRBs sampled. Furthermore, a δ13C analysis in a respiration study indicated some biodegradation of crude oil, from respiration of oil instead of organic matter present. The implementation of these experiments helped identify and better understand the SSRBs and their biodegradability potential. This information obtained may offer us new solutions to challenges in environmental and waste cleanup. Also, help us determine how the oil spill has affected the supratidal area along Fourchon Beach, Louisiana and how best to proceed with cleanup efforts.