Size-fractionated chlorophyll concentrations, Mississippi Canyon, Gulf of Mexico, spring 2012 and 2013.

Two research cruises, one in 2012 one in 2013, were conducted 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. Size-fractionated chlorophyll samples were collected from full water column CDT casts and microzooplankton grazing experiment samples at various stations in the Gulf of Mexico during April 2012 and April 2013. Chlorophyll concentrations were calculated according to EPA Method 445.0. Grazing experiments were carried out according to now-standard dilution method protocols first used by Landry and Hassett (1982).