ALKOR AL394

During its 394th cruise, the German research vessel ALKOR delivers nine so-called mesocosms to Finland for the next field experiment of the SOPRAN project (Surface Ocean Processes in the Anthropocene). The work is coordinated by GEOMAR | Helmholtz Centre for Ocean Research Kiel.

Ocean acidification, a chemical process triggered by the uptake of carbon dioxide from the atmosphere, is a threat to many calcifying organisms. In the more acidic water, they have difficulties to build their shells and skeletons. But there seem to be creatures, too, that benefit from the change in ocean chemistry: Cyanobacteria. Some of those organisms are also known as “blue-green algae” are toxic to humans and animals – a reason why beaches have to be closed off during cyanobacteria blooms every summer.

Laboratory experiments show that a higher amount of carbon dioxide in sea water stimulates the bacteria’s growth. Scientists from SOPRAN (Surface Ocean Processes in the Anthropocene) investigate if this also is true for the Baltic Sea. For their field experiment, the German research vessel ALKOR brings nine mesocosms to Tvärminne Zoological Station at Finland’s southernmost tip. The mesocosms are anchored close to the coast. Their 25 metres long plastic tubes enclose 70 cubic metres of sea water that can be enriched with carbon dioxide. For eight weeks, the scientists will analyse the development inside the mesocosms and collect samples for further measurements.

During its AL397 cruise (August 8-13, 2012), ALKOR will transport the mesocosms back to Kiel.