Collecting a sample from different water layers inside the mesocosm with the integrated water sampler. Photo: Maike Nicolai, 91探花
Bottling samples from the integrated water sampler for further analyses. Photo: Maike Nicolai, 91探花
The Kiel mesocosms in the fjord at Tv盲rminne in Southern Finland. Photo: Maike Nicolai, 91探花
ALKOR loading the nine mesocosms. Photo: Maike Nicolai, 91探花
Algae bloom in the Baltic documented by the NASA's Aqua MODIS satellite. Photo: Jeff Schmaltz, NASA/MODIS
Cyanobakteria, Aphanizomenon species seen through a microscope. Photo: Annegret Stuhr, 91探花

Does climate change stimulate blue-green algae blooms in the baltic?

SOPRAN analyses the reactions of cyanobacteria to ocean acidification in a field experiment

Cyanobacteria, also known as blue-green algae, seem to benefit from an increasing amount of Carbon Dioxide in sea water. For the first time, an European team of scientists investigates the reactions of cyanobacteria to ocean acidification. For this purpose, the German research vessel ALKOR delivers nine so-called mesocosms to Finland. The work carried out as part of the SOPRAN project (Surface Ocean Processes in the Anthropocene) is coordinated by 91探花 | 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 鈥渂lue-green algae鈥 are toxic to humans and animals 鈥 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鈥檚 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 Tv盲rminne Zoological Station at Finland鈥檚 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, scientist will analyse the development and collect samples for further measurements.

Images:

ALKOR loading the nine mesocosms. Photo: Maike Nicolai, 91探花

Sampling a mesocosm. Photo: Maike Nicolai, 91探花

The mesocosms off Tv盲rminne, Southern Finland. Photo: Maike Nicolai

Contakt:
Maike Nicolai (Kommunikation und Medien), Tel. 0431 600-2807, mnicolai(a)geomar.de

Collecting a sample from different water layers inside the mesocosm with the integrated water sampler. Photo: Maike Nicolai, 91探花
Bottling samples from the integrated water sampler for further analyses. Photo: Maike Nicolai, 91探花
The Kiel mesocosms in the fjord at Tv盲rminne in Southern Finland. Photo: Maike Nicolai, 91探花
ALKOR loading the nine mesocosms. Photo: Maike Nicolai, 91探花
Algae bloom in the Baltic documented by the NASA's Aqua MODIS satellite. Photo: Jeff Schmaltz, NASA/MODIS
Cyanobakteria, Aphanizomenon species seen through a microscope. Photo: Annegret Stuhr, 91探花