Annual evolution of downward particle fluxes in the Western Bransfield Strait (Antarctica) during the FRUELA project

Particle fluxes in the SW Bransfield Strait basin were determined by means of sediment traps deployed at intermediate and near-bottom water depths. Sampling was carried out during a complete year, from March 1995 to February 1996, during the FRUELA experiment. Total mass fluxes, major constituents, and 210Pb were analyzed to study the temporal evolution of downward particle fluxes and to determine the origin of particles transferred to this basin. Mid-depth particle fluxes were much lower and showed a different temporal evolution than those near the bottom. Particle flux variability was mainly related to ice dynamics and biological productivity. The particulate matter transfer and export at mid-depth was very low and most of it took place between November and February during four 15-day sampling periods of the year. Downward carbon export at mid-depths was produced mainly by fecal pellets. The near-bottom fluxes were high (1.1–5.3 g m−2 d−1) during the whole year, and the greatest carbon transfer took place by lateral transport of resuspended and winnowed particulate matter.