Biogeochemistry of a late marginal coccolithophorid bloom in the Bay of Biscay

Coccolithophores, among which Emiliania huxleyi (Ehux) is the most abundant and
widespread species, are the dominant calcifying phytoplankton in the temperate zone
of the world’s oceans. Within the framework of the “Climate and Atmosphere” Belgian
Federal Science Policy Office programme, the continental margin of the Northern
Bay of Biscay (North Atlantic Ocean) was visited in June 2006 during a multidisciplinary
investigation of a late-spring bloom dominated by Ehux. Field sampling was
assisted by daily transmission to the RV Belgica of remote sensing images, indicating
the bloom development in the area.
Various stations on the shelf and the shelf-break were sampled for the vertical distributions
of nutrients, Transparent Exopolymer Particles (TEP), chlorophyll-a and
particulate carbon concentrations. These data will be presented, here, in relation with
14C based integrated primary production, dissolved esterase activity and the bacterial
community structure to emphasize the importance of coccolithophorid blooms in the
biogeochemistry of the Northern Atlantic’s continental shelf.