Gerli Albert1, Liina Pajusalu1, Christopher D. Hepburn2 and Georg Martin1
1 Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618 Tallinn, Estonia
2 Department of Marine Science, University of Otago, PO Box 56, Dunedin, New Zealand
The carbon acquisition strategies of aquatic photosynthetic organisms play a key role in the growth and survival of a species. There is much research indicating the predicted changes (e.g., the balance between carbonate species: CO2, HCO3−, CO32−) in the seawater carbonate chemistry, due to Ocean Acidification (OA), could affect benthic primary producers and their communities. So far, too little attention has been paid to what extent carbon availability limits productivity in coastal waters, especially in the Baltic Sea. Perhaps the most glaring hole in our knowledge surrounds the “CO2 fertilisation effect”. There is a need to pay more attention to vegetated coastal ecosystems as they will have an important role to mitigate ocean acidification. The identification of the carbon uptake strategies in macroalgae (i.e. exclusive CO2 users, and/or HCO3¯users) could indicate how complicated coastal ecosystems will respond to the predicted changes in seawater carbon chemistry. Few studies have examined the carbon physiology of macroalgae within the context of climate changes in the brackish Baltic Sea. My PhD focuses on macroalgal communities in the brackish water of the NE Baltic Sea. So far, our research has shown that even species growing together in the same habitat may have significantly different carbon uptake mechanisms. Furthermore, the “CO2 fertilisation effect” accelerates the growth of filamentous fast-growing macroalgae which may enhance indirectly eutrophication, known as one of the major issues in the Baltic Sea.