This study was done to evaluate the diversity of indigenous microbial communities from sandy beaches before the Gulf of Mexico oil spill in 2010, and to characterize potential changes in the community diversity during and after the oil spill.
More...This study was done to evaluate the diversity of indigenous microbial communities from sandy beaches before the Gulf of Mexico oil spill in 2010, and to characterize potential changes in the community diversity during and after the oil spill. This study was conducted at the public beaches on Grand Isle, Louisiana, and Dauphin Island, Alabama. Samples were acquired from May 2010 through May 2011. Beaches at Grand Isle were heavily oiled in June-August, 2010, and cleanup of the oil continued through February 2011. Extensive cleanup comprised digging up oil-contaminated sand to at least 1 m depth and sandwashing the sediment onsite, or removing the contaminated sand and replacing the beaches with clean sand from offsite. The beaches at Dauphin Island began receiving tarballs June 2010, and continued being contaminated by weathered oil and tarballs through August 2010. Cleanup of the tarballs started June 2010 and continued through December 2010. Cleanup comprised manual picking of tarballs from the surface of the sediment, or digging up contaminated sand to about 1 m depth and sandwashing the sediment onsite. At both beaches, large amounts of sand were piled up, dug from deep and wide trenches, and moved around the beach with heavy machinery. Bacterial communities were assessed from the sands along transects perpendicular to the shore. Sampling locations were between 10 and 30 m apart, depending on the beach profile, and sand at each location was collected from 0 cm, 5 cm, and 15 cm depth. The results are amplicon pyrosequence libraries of single-direction reads generated using multiplexed, bar-coded primers targeting the V1-V3 region of the bacterial of 16S rRNA gene.
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