The future does not look rosy for the Plankton of the polar seas

produced by The Plankton in the sea is at the base of the food chain, oxygen and binds carbon. Two new studies with the participation of the ETH Zurich suggest that on the cold waters of specialized organisms less adaptable than those from warmer ocean regions. Many kinds of the polar sea plankton are likely to be displaced, therefore, in the course of the climate change . With impact on fish stocks and food base of people, such as the ETH announced on Thursday.

Plankton is, for example, bacteria, viruses, and plant and animal individual learning. These micro-organisms, which drift with the ocean currents through the world's oceans, are at the base of all food chains in the sea. Algae and blue-green algae operate photosynthesis and make oxygen, they also bind carbon, and "swallow" a part of the man-made CO2 emissions.

35'000 water samples

to explore the diversity of the plankton, to sail by the "Tara Oceans"Expedition from 2009 to 2013, the world, and gained to 210 over all the seas of the world across approximately 35'000 water samples from various water depths. An international research team with Swiss participation now reports of new analyses of data from this Expedition.

In two studies in the journal "Cell" describes the consortium, the global distribution of species diversity, and genetic diversity of the plankton. Also involved are Researchers to Shinichi Sunagawa from the ETH Zurich and the Swiss Institute of bioinformatics (SIB).

In one study, the scientists show that the species diversity of the plankton is distributed across the oceans unevenly. Although the oceans constitute a single, coherent Ecosystem, the species diversity of the plankton at the poles.

Less adaptable

In the second study, the researchers examined to Sunagawa in particular, the bacteria and archaea, are part of the plankton. They found that these microbes have in the warmer waters over a larger gene pool than those in the polar seas. The make them more flexible, wrote the ETH. If necessary, the microbes could, as a community, different genes on or off, and rapidly adapt to changing conditions.

Because you have to be poorer and less genetically diverse, and the microbial communities of the colder seas are difficult, your metabolism at higher water temperatures to adapt, it was called more. "Our results suggest that they could be more focused on your specific niche to specialize," said Sunagawa. Therefore, the microbes of the colder ocean regions might one day be ousted from the competition from warmer oceans.

Changes in the composition of the plankton changes, the food base for fish and ultimately the people. The Northern seas are the reasons important fish. The consequences of the warming of the sea water and the associated changes in the plankton for the Ecosystem as a whole are difficult to predict, the research consortium.

The water samples were collected during a relatively short time period of only four years, so that Trends are difficult to read. The researchers therefore call for long-term and interdisziplären projects, to monitor the developments. (nag/sda)

Created: 14.11.2019, 16:13 PM