Spatially differentiated strategies for coastal management of fish community structure and eutrophication symptoms

The combination of excessive nutrient loading and depletion of large fish predators have dramatically altered the Baltic Sea ecosystem. However, responses to such anthropogenic pressures are likely modified along a strong north-south biogeochemical gradient, including variation in colored substances influencing light climate. Light availability, in turn, controls benthic primary production which may cascade up the food web and affect fish community structure and production. Still, the net effect of shifting the balance between benthic and pelagic productivity on fish is unknown in the Baltic Sea. C ombining comparative field studies, experiments and bioeconomic theory we will produce knowledge about (1) the interaction between top-down (predation) effects and bottom-up drivers (nutrient and light availability) in structuring coastal food webs and (2) evaluate if the relative efficiency of such top-down vs bottom-up manipulations to mitigate eutrophication symptoms change depending on light climate and geographic location. Also, by linking new ecological knowledge to economics, we will provide an evaluation of policies for spatially resolved integrated coastal management.