Climate change started in the Wadden Sea

Clear signs of climate-related changes already visible

Wadden Sea near Sylt Alfred Wegener Institute for Polar and Marine Research
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Significant signs of climate change are already evident in the North German Wadden Sea. This is how the plankton season shifts, the mud flows back and species migrating from the southern climes are getting ready. This is the result of 25 environmental scientists who met in the Wadden Sea Station Sylt to evaluate current results.

Concerned, the researchers are registering a retreat of the mudworm and an expansion of coarse-grained sandy soils. In it they see signs of long-term problematic development. Because enough new sediments were deposited, the Watts could follow the slow rise of the sea level over thousands of years. But this growth of the tidal flats now seems disturbed. The sea level is rising faster.

"Not only does this change the ecology of the Wadden Sea, but humans must also adapt their colonization on the coast to this new situation, " says Professor Karsten Reise, head of the Wadden Sea Station Sylt.

Global warming is already changing plankton. The summer season has grown by a month, shifting plankton production into the autumn. Then it mainly benefits the Pacific Oysters, which are now cultivated for cultural purposes and now overgrow many mussel beds. Twenty years ago, it was still believed that these oysters can not multiply in cold North Sea water. But with the warming of the North Sea, the invasion of the oysters took its course.

Pleasing are the declining nutrient inputs. Twenty years ago, coastal waters showed the effects of severe over-fertilization. Massive algae mats still appear in the watt, but the seagrass stocks seem to be recovering. However, this will only continue until climate change drives seagrass into the ecological confinement due to higher water levels and more swell. Seagrass beds are a significant habitat and as a nursery for many fish a key component in the ecosystem. "Such analyzes are a prerequisite for sound trend assessments of how the Wadden Sea ecosystem will continue, " explains Reise. display

The shallow Wadden Sea is extremely sensitive to climate change and the resulting higher water levels. The warning signals from the coast indicate the need to drastically reduce greenhouse gas emissions.

(Alfred Wegener Institute for Polar and Marine Research, 07.03.2007 - NPO)