12.12.2025Hydrobiology Limnology Award for Mara Knüsel’s dissertation

In her dissertation supervised by Prof. Dr. Florian Altermatt, Mara Knüsel investigated one of Switzerland’s most hidden and understudied ecosystems: groundwater. While groundwater is a crucial drinking water resource, its function as an ecosystem is still poorly understood. Collaborating with several hundred local drinking water suppliers, Knüsel was able to generate the first nationwide dataset on Swiss groundwater fauna. This participative methodology is worldwide unique at the given scale and demonstrated that Swiss groundwater harbors a rich biodiversity. Many amphipod species, the focus of the study, were found to have small distribution ranges and some are likely to be endemic to Switzerland. Furthermore, multiple species were previously unknown and turned out to be new to science.

“It is astonishing that there is an ecosystem just below our feet, which we still understand so little about.”

While biodiversity and occurrence patterns of subterranean organisms are shaped over thousands of years, Knüsel could also show that present-day aboveground land use can be linked to the occurrence of groundwater amphipods. Her pioneering work provides a foundation for better understanding and assessing Switzerland’s groundwater fauna.

A short film portraying the research project was produced by Eawag:
https://www.youtube.com/watch?v=C_hoMg_pr1Y