Bacterioplankton Diversity, near-shore to deep-water Barataria Bay, Hackberry Bay, and Terrebone Bay, March-September 2010.

In spite of the importance of bacteria for the health and function of the Gulf of Mexico, little is known about the diversity and structure of bacterioplankton communities in the northern Gulf of Mexico. Post-spill research has emphasized selected sub-systems rather than comprehensive surveys, while pre-spill data are almost entirely lacking. We initiated a massively parallel high-throughput sequencing analysis of 44 samples distributed across the northern Gulf of Mexico encompassing transects from near-shore to deep-water stations and depths from 2 m to 1700 m. We targeted the 16S rRNA gene to provide information on bacterioplankton diversity (richness and structure), and used primers that amplify members of the Bacteria and Archaea. We obtained > 400,000 sequences using a 454 pyrosequencing platform. In addition, we conducted a similar analysis of bacterioplankton communities in Barataria Bay that were sampled during and after the period of high freshwater throughput from the Davis Pond Freshwater Diversion. No prior information exists on the diversity of Barataria Bay bacterioplankton. We also sampled oysters (Crassostrea virginica) from Hackberry Bay (August, 2010) and from Terrebonne Bay (September, 2010). We analyzed both stomach and gut contents of replicate animals to create the first comprehensive analysis of the oyster digestive system microbiome. Finally we have conducted a focused analysis of the diversity of alkane-degrading bacteria in the northern Gulf of Mexico and Barataria Bay. We have used the alkB gene as a target and created traditional clone libraries for a sub-set of the samples used for 16S rRNA gene assays. Our results provide the first detailed pre-spill picture of total bacterioplankton diversity and the diversity of alkane degraders in the northern Gulf of Mexico. We also have developed the first analyses of these groups for Barataria Bay and generated the first analyses of the C. virginica microbiome.