The goal of this project is to assess the effects of changing ice-cover regimes on aquatic primary production and carbon metabolism in northern freshwater and brackish water coastal ecosystems. Northern aquatic ecosystems are seasonally variable due to long, cold and dark ice-covered winters as well as 24-hour sunlight during summer. A warmer climate has effects on the extensions and magnitudes of snow- and ice-cover, with shorter duration of ice-cover expected for northern aquatic ecosystems. The ice-cover is important for carbon accumulation (CO2 and CH4), aquatic-atmosphere gas exchange and a number of biological processes. Hence, a changing ice-cover regime will have important implications for the function of northern aquatic ecosystems and for the role of these systems in the global carbon cycle.
Benthic and pelagic production in coastal ecosystems of the northern Baltic Sea
The northern basins of the Baltic Sea are relatively shallow systems, implying that coastal processes can be of great significance to this area. It is likely that benthic primary production is an important part of the basal production in coastal ecosystems, because of high nutrient concentrations in the sediments and available sunlight. Coastal habitats are also important recruitment areas for most fish species. However, colored organic matter, which is transported into the marine system via rivers, can potentially shift the basal production from benthic and autotrophic to pelagic and heterotrophic. Thus, colored organic matter is likely a key factor influencing the ecosystem function in the northern Baltic Sea. In this project we are studying benthic and pelagic primary production and bacterial production in northern Baltic Sea coastal zones with varying input of colored organic matter. Furthermore, we are aiming at quantifying the importance of the different production modes to the production of higher trophic levels, e.g. fish. The project is part of the strategic research program ECOCHANGE.