German-Tunisian project to preserve the coastline

Changes to the coasts of our oceans have always been a natural and constant companion for the inhabitants. However, due to the climate crisis, they can increase dramatically and get out of hand. Rising sea levels and an increase in extreme storms are causing severe erosion on many coasts - not only in the North and Baltic Seas, but also in the Mediterranean. The island of Djerba, a popular holiday destination in Tunisia, is a clear example, where the erosion is particularly pronounced at up to more than 4 metres per year. This means that both residents and tourists are seeing their beaches shrink from year to year.

With the help of seagrass plantations, researchers at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) are working with the Biological Institute Helgoland and the Wadden Sea Station Sylt as well as the University of Sfax in Tunisia to slow down this process. This project is being funded as part of the UN Ocean Decade, as social and ecological processes go hand in hand here.

In the past, fishing and beach clearance have severely decimated the dense and extensive seagrass meadows in the Mediterranean around Djerba. The remnants of seaweed on the beach were seen as a deterrent for holidaymakers. In the meantime, severe coastal erosion and the loss of entire stretches of beach on the island are omnipresent. A rethink is taking place. Researchers at the University of Sfax and the AWI are now developing new approaches in collaboration with local groups, such as fishery representatives, youth organisations and hotel operators. Seagrass can stabilise beaches and thus contribute to their preservation and that of the ecosystem, it increases biodiversity and - if communicated correctly - offers a market as a tourist attraction, for example through guided snorkelling or boat tours. In many coastal areas, this "working with nature" is more successful than working against nature.

"I am very impressed by the commitment of the local groups involved," says Dr Eva-Maria Brodte. "Thanks to our Tunisian partners at the university in Sfax, who have done a lot of preparatory work on Djerba, all the groups are very helpful and trusting." The workshop on Heligoland is already the third; two working meetings have already taken place on Djerba in October 2022 and spring 2023. Preparations are now starting for the practical test phase with seagrass planting in the project. Over the course of the next year, the project participants will plant seagrass at selected test sites and monitor and control the development through scientific data collection. The first results will hopefully be available after a year.