Abstract
Climate change has been predicted to cause increased river inflow into the Baltic Sea, leading to decreased salinities, higher concentrations of dissolved organic carbon (DOC), and changed light climate and hydrography. Such changes may decrease phytoplankton primary productivity due to poorer light climate, and increase bacterial productivity due to high input of DOC and decreased competition from phytoplankton for inorganic nutrients. The aim of this project is to clarify how primary and bacterial productivity will change due to predicted climate related changes in the Baltic Sea, and to elucidate how this affects productivity at higher trophic levels, e.g. fish. Experiments are planned to study the spatial and temporal variation of bioavailability of DOC in the Baltic Sea. The structure, function and efficiency of marine food webs exposed to varying light, hydrological conditions and DOC and inorganic nutrient concentrations will be studied in mesocosm experiments. The experiments will comprise organisms from phytoplankton-bacteria to fish. The results of field studies and experiments will be used for development and parameterization of a food web model that will be used to estimate productivity changes in the Baltic Sea. Predicted changes in light, DOC, inorganic nutrients by oceanographic models will be used to estimate productivity in the Baltic Sea in the next hundred years. The model will be adapted to hydrographical conditions in the Baltic Sea.
Sweden