SEASONAL COMPARISONS OF ROSE BENGAL STAINED BENTHIC FORAMINIFERA INHABITING THE WESTERN ANTARCTIC PENINSULA SHELF

In an effort to better understand the impacts of seasonal productivity on foraminiferal assemblages, the SEASONS project (Seasonal Ecological Analysis of Seafloor Organic Nutrient Supplies) examined sediment core samples that were collected across a surface productivity gradient in the northern Gerlache-southern Bransfield Straits region (western Antarctic Peninsula) in Antarctica in April 2008 (following a surface productivity bloom) and July 2008 (low surface productivity). Distribution patterns of Rose Bengal stained benthic foraminifera were determined from core samples taken in water depths of approximately 600 and 1200m. Samples taken from sites in the southern Bransfield Straight had a low productivity surface and lower levels of alkalinity and dissolved inorganic carbon than sites taken from the northern Gerlache Straight, which has a higher surface productivity. Dominant species found in this region included: Pullenia bulloides, Astrononion echolsi, Bolivina pseudopunctata and Globocassidulina sp. and differences in assemblage characteristics appear to be related to changes in organic input over space and time. Results from this study yield important information regarding the relationship between seasonal productivity and distributions of foraminiferal assemblages. This information will provide critical base line information for seafloor microfaunal ecosystems and generate modern analogs for regional reconstructions of seasonal variability based on fossil foraminifera.