Flux and modification of sinking particles: Three field studies in the Southern Ocean

Abstract

The surface ocean is coupled with the deep ocean via sinking particles that transport carbon to depth: the biological pump. Only a small amount of the organic matter being formed at the surface reaches the seafloor, the remains are recycled. Most of the modification occurs in the mesopelagic. This thesis introduces further developments of a novel technique to examine sinking particle flux. The use of free-floating sediment traps equipped with polyacrylamide gels allows drawing conclusions on export fluxes on the base of intact individual particles. In three field studies, these data were compared to export flux data received with other sampling technologies. The field studies took place in different regions of the Southern Ocean. The focus of all studies was to investigate sinking particles in the mesopelagic and identify export driving processes. Overall, export fluxes were dominated by zooplankton mediated material (faecal pellets or aggregates of faecal matter) during each study.