The US Geological Survey, Wyoming-Montana Water Science Center (WY-MT WSC), is offering a funding opportunity is to provide sample collection, analysis, and interpretation regarding the extraction of genetic information from sediment and water-column samples collected from approximately 12 sites on Lake Powell during two synoptic cruises, CY 2014 and 2015. This work is being done in support of a USGS funded project on mercury cycling in Lake Powell. Specifically, sediment and water column samples will be collected concomitant with those collected for geochemical analyses using sterile techniques. Total nucleic acids will be extracted using a combined physical and chemical lysis method. A set of broad and targeted primer sets will be used to assess the biodiversity of the microbial communities thought to participate in Hg(II-)-methylation. Community biodiversity will be assessed by subjecting genomic DNA to polymerase chain reaction (PCR) using universal primers targeting the V8 hypervariable region within the 16S rRNA gene. The biodiversity of potential methylators (e.g., SRB, IRB, methanogens, firmicutes) will be assessed using primers for the specific amplification of a region of hcgAB, the protein product of which was recently demonstrated to be required for the methylation of Hg. A forward primer specific to the conserved corrinoid binding domain of HcgA and a reverse primer specific to the unique ferredoxin binding domain of HcgB will be developed along with the development of primers for the specific amplification of target functional genes. PCR amplicons will be barcoded and subjected to multiplex pyrosequencing using the GS FLX Titanium platform.