Climate change threatens habitats in the Wadden Sea: study sounds the alarm!

Climate change threatens habitats in the Wadden Sea: study sounds the alarm!

The increasing challenges of climate change do not stop at the Wadden Sea. For some time now there has been a worrying trend of significant habitat change in this unique ecosystem. On September 16, 2025, an intensive examination of life strategies in the Wadden Sea begins for a university course at the University of Münster.

The group consists of six master's students in biology and three in water sciences, led by Dr. Hans-Ulrich Steeger will take part in a two-week excursion. They use the marine biological mudflat station in Carolinensiel, which this year is not below sea level and thus enables the courses to be held. The students are here to conduct various scientific excursions and research the marine life of the Wadden Sea.

Excursions in the Wadden Sea

Two vans were organized for the excursions. Steeger registers the group with the beach warden and informs the students about the necessary equipment and techniques for working on the mudflats. As the excursion continues, the students catch invertebrates, which are later examined in the wet laboratory and released back into their habitat. Steeger not only explains the life strategies of the organisms, but also historical aspects, such as soap production in the Middle Ages.

The group collects crabs, mussels and algae, which are central elements of the Wadden Sea ecosystem. On the way back to the Wadden station, Steeger explains the importance of the Wadden Sea as a national park and reports on the failed tourism development plans that could endanger the unique nature.

In addition, the students cook their own meals in the Wattstation self-catering house, while Dr. Steeger gives exciting insights into the history of East Frisia and the development of the landscape over thousands of years. The research at the marine biological mudflat station, which was founded in 1970, serves both teaching and scientific investigation.

Climate change in the Wadden Sea

In parallel to these findings experienced on site, there are alarming research results on the increasing warming of the North Sea. Researchers at the Sylt Wadden Sea station have published a comprehensive study that addresses the serious effects of climate change on the Wadden Sea. This research was published in the journal Marine Biodiversity to mark the station's 100th anniversary.

Over the last 60 years, the North Sea has warmed on average twice as much as the global ocean. This has a serious impact on the ecosystem: mild winters and very warm summers lead to more frequent heat waves, with temperatures 3 to 5 degrees above average. Physical changes strongly influence the expansion of ecologically essential habitats, such as seagrass meadows and mussel beds.

A particularly worrying trend is the shifts of species that are unable to adapt their ranges. Fish that use the Wadden Sea as a nursery are particularly badly affected. In recent years, studies have shown a significant decline in the population sizes of fish, plants and birds in the Wadden Sea. These results are based on an analysis of over 3,000 time series of population sizes collected from 200 stations along the coast.

However, some developments can also be viewed as positive: certain species, such as the Pacific oyster and the American razor clam, are benefiting from environmental change. Nevertheless, the decline of well-known species such as Atlantic cod and various flatfish is alarming. The holistic approach of these studies aims to improve conservation strategies and management of the 500 kilometer long coastal strip.

Overall, the experiences and scientific findings collected illustrate how important research and awareness-raising is for the Wadden Sea. Given the rapid changes, it is crucial to take timely action and create awareness of the unique nature of the Wadden Sea. While students at the University of Münster work on their field trips, the fate of this ecosystem remains uncertain and requires urgent scientific attention.

For further information about the courses at the University of Münster, visit University of Münster. Current data on the effects of climate change on the Wadden Sea can be found at German climate portal and specific biodiversity studies published by University of Oldenburg.