The latest news from Eawag

When, where and why do different fish species migrate – and how successfully do they manage to do so despite the barriers posed by hydroelectric power stations? Eawag researchers are investigating this by tagging fish and tracking their signals over a period of several years. Initial analyses have yielded surprising results.

A new study finds the link between biodiversity and poverty was shaped by colonial history rather than by nature itself—and argues that conservation built on the opposite assumption risks repeating it.

Native freshwater mussels are among the most endangered animal groups in the world. Their populations are also declining in Switzerland. Yet, as natural water filters, they play a vital role in our water bodies. To protect them, we need to study them more closely, but this is difficult as many species are almost impossible to distinguish morphologically. A study by the aquatic research institute Eawag shows that genetic data could provide a valuable basis for this.

Green roofs differ from ground-level habitats in terms of biodiversity. This can help to boost biodiversity in cities.

Toxic blue-green algae blooms are a threat to lake ecosystems and can be toxic for humans and animals. At present, it is only possible to predict roughly when and where such blooms will form – based on water temperature and nutrient levels. Now, a long-term study by Eawag researchers shows that the accumulation of blue-green algae in a lake depends crucially on other plankton species: some organisms promote blue-green algae blooms, whilst others can prevent them even under favourable environmental conditions.

As the leader of the research group on Multifunctional Blue-Green Design at Eawag, Lauren Cook explores the intricate trade-offs between flood management, biodiversity, and urban heat. In this interview, she challenges the simplicity of "nature-based solutions" and explains how decision-making tools can help find the optimal solution for competing goals.

A new modelling approach provides a more accurate picture of how biodiversity in cities will evolve as a result of climate change.

The current heatwave makes it easy to forget that the first half of 2025 was already marked by severe drought and that snow reserves from the winter were low. A review of water policy developments in 2025 shows that, rather than the availability of water, the Federal Parliament once again focused on the use of hydropower. On the subject of water quality, discussions centred on setting limit values for PFAS and calls for a simplified authorisation process for pesticides.