The Baltic Sea is contaminated, and the atmosphere is today the major source of persistent organic pollutants (POPs) to the Baltic Sea. This project will generate new knowledge on how flux of POPs from air to sediment in the Baltic Sea is controlled by the organic carbon cycle, and thereby gauge if and why the sediment POP sink in the Baltic Sea could be affected by potential future changes in trophic status and terrestrial carbon export. Sediment is a key to understand POP cycling in the Baltic Sea since the sediments act as both sink and source of chemicals to water and fish, yet current knowledge is critically limited. Using novel methods and a combination of empirical field observations, lab experiments and model simulations, the project will explore the impact of trophic status (eutrophic–mesotrophic-oligotrophic) and organic carbon origin (terrestrial versus marine) on POP fluxes from air to sediment, and ultimately the magnitude of Baltic Sea sediments as a sink for POPs.
