Using ecosystem engineering for water purification – a transdisciplinary approach

The beaver, an ecosystem engineer, is expanding its presence in the rivers of Europe. While beaver management has traditionally focused on addressing conflicts arising from beaver damming, it has also been recognized for providing ecosystem services such as enhancing biodiversity and purifying water. In a collaborative and transdisciplinary project aimed at monitoring and managing beavers in Switzerland, policymakers, environmental managers, consultants, and scientists collaborated to quantify the ecosystem services associated with beaver damming. The project involved a quantitative investigation, including the beaver census to determine the number and locations of beavers in all Swiss streams, identification of beaver dams, and an assessment of the impact of beaver damming on water quality across the country. In 2021, 400 volunteers and 70 game wardens underwent regional training and, following guidelines, questionnaires, and video instructions. In winter 2022 they independently surveyed 7,000 km of the Swiss river network, identifying 1,382 beaver territories with 1,316 beaver dams. Water samples were collected upstream and downstream of all beaver-dammed river reaches in winter and summer 2022. The samples were cooled and sent by post to a laboratory for analysis. Project management and volunteer training were coordinated by the national beaver managment, part of the National Data and Information Centre for Swiss Fauna (info fauna). . An international team of scientists from Switzerland, the United Kingdom, and the Netherlands analyzed ecosystem services, with funding provided by the Swiss Federal Office of the Environment (FOEN). The collaborative and transdisciplinary nature of the project yielded valuable datasets for river management and fundamental science. These datasets are now integrated into national online data repositories accessible to all cantonal authorities responsible for river management and restoration in order to focus efforts on  river sections with high ecosystem service value. The direct connection to national policymakers raises optimism for a shift from the current restrictive beaver management approach to a more ecosystem-service-oriented strategy. The project also provided insights into the effective involvement and limitations of volunteers through citizen science.