Living Bulimina marginata in the SW Atlantic continental margin: Effect of the Subtropical Shelf Front and South Atlantic Central Water

•B. marginata inhabits salinity of 25–35 PSU and temperature of 5–20 °C.•B. marginata as proxy for STSF and SACW.•B. marginata dominates where seasonal stratification is pronounced.

The western South Atlantic continental margin, between 27° and 37°S, is dominated by three main water masses: cold-fresh Subantarctic Shelf Water (SASW), warm-salty Subtropical Shelf Water (STSW) and Plata Plume Water (PPW). Despite the large seasonal variability of PPW extension along the shelf, an intense and relatively stable temperature-salinity gradient separates the SASW and the STSW forming the Subtropical Shelf Front (STSF) around 32°S. This article demonstrates that the distribution of Bulimina marginata, (shelf environment and deep-sea) a species of benthic foraminifera is influenced by the front location and it can be used as a proxy of the STSF in sediment core analysis.