Sediment and Benthic Foraminifera Assessment, DeSoto Canyon, 2010-11-01 to 2011-02-28

We proposed to assess the impact of the Deepwater Horizon oil and dispersants on sediments and benthic communities on the West Florida Shelf and Slope. In particular, we proposed the assessment of subsurface oil and dispersants to gauge the effects on benthic habitat critical to nearby fisheries and marine protected areas. We proposed to use a new Ocean Instruments MC-800 multicore system to sample sediments in two depth transects that intersect suspected layers of subsurface oil at approximately 400 m and 1400 m water depth. The transects were aligned with those identified in the College of Marine Science’s Initial Baseline Survey. One transect sampled areas influenced by the spill, and extended from offshore Pensacola (DSH) to approximately 1600 m in the Desoto Canyon. The second transect extended from just south of Panama City (PCB) to 1200 m. Core samples were dated using short-lived radioisotopes, analyzed for petroleum byproducts by organic and inorganic chemistry, including organic compounds and metals specific to Deepwater Horizon petroleum. In addition, benthic foraminifera abundance and their stable isotope geochemistry will be quantified to assess the impact on benthic communities. In this way, we documented the “bathtub rings” of sub-surface oil and their effects on benthic habitats.