Seasonal flux and assemblage composition of planktic foraminifera from the northern Gulf of Mexico, 2008-11

The U.S. Geological Survey anchored a sediment trap in the northern Gulf of Mexico to collect seasonal time-series data on the flux and assemblage composition of live planktic foraminifers. This report provides an update of the previous time-series data to include results from 2011. Ten species, or varieties, constituted ~92 percent of the 2011 assemblage: Globigerinoides ruber (pink and white varieties), Globigerinoides sacculifer, Globigerina calida, Globigerinella aequilateralis, Globorotalia menardii group [The Gt. menardii group includes Gt. menardii, Gt. tumida, and Gt. ungulata], Orbulina universa, Globorotalia truncatulinoides, Pulleniatina spp., and Neogloboquadrina dutertrei. The mean daily flux was 205 tests per square meter per day (m^-2 day^-1), with maximum fluxes of >600 tests m^-2 day^-1 during mid-February and mid-September and minimum fluxes of <60 tests m^-2 day^-1 during mid-March, the beginning of May, and November. Globorotalia truncatulinoides showed a clear preference for the winter, consistent with data from 2008 to 2010. Globigerinoides ruber (white) flux data for 2011 (average 30 tests m^-2 day^-1) were consistent with data from 2010 (average 29 m^-2 day^-1) and showed a steady threefold increase since 2009 (average 11 tests m^-2 day^-1) and a tenfold increase from the 2008 flux (3 tests m^-2 day^-1).