Bacterial production and bacterial abundance in Gulf of Mexico, spring 2012 and spring 2013.

Two research cruises, one in 2012 and one in 2013, were conducted in the Gulf of Mexico to continue to monitor the microbial and planktonic communities and to assess rates of particle flux and the rates of removal of PAHs from the system via this process and accumulation of PAHs in bottom sediments. The bacterial production experiments aim to quantify the amount of bacterial biomass produced at different locations within the Gulf of Mexico. The methods are based on using radioisotope-labeled compounds to quantify rates of DNA synthesis (using thymidine) or protein production (using leucine) by microorganisms (Fuhrman and Azam 1982; Kirchman et al. 1985). These data complement the primary production and respiration experiments; the three sets of data will be combined to quantify microbial processing of organic carbon in the Gulf of Mexico.