Department Aquatic Ecology

Aquatic Ecology

The Aquatic Ecology department at Eawag consists of eight research groups and covers a wide range of different disciplines in ecology and evolutionary biology, ranging from the individual level to associations and ecosystems. Learn more

The latest news from our department

Indirect effects drive evolution

Martin Schäfer taking a water sample from one of the test ponds (Photo: Christoph Walcher, Eawag).
August 28, 2025 –

An international study conducted in Eawag's experimental ponds demonstrates how indirect ecological effects influence the evolution of species.

An international study conducted in Eawag's experimental ponds demonstrates how indirect ecological effects influence the evolution of species.
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How much water is left for nature? – The search for the appropriate environmental flow

July 2, 2025 –

After water is diverted for hydropower, rivers are often left with very little streamflow for nature. A new report provides an overview.

After water is diverted for hydropower, rivers are often left with very little streamflow for nature. A new report provides an overview.
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Gaining time in the fight against the quagga mussel

Filters and heat exchangers can protect infrastructures from clogging by mussels (Photo: Eawag, Linda Haltiner).
April 8, 2025 –

To contain the spread of the invasive quagga mussel, Eawag researchers recommend swift action based on comprehensive prevention, early detection and containment.

To contain the spread of the invasive quagga mussel, Eawag researchers recommend swift action based on comprehensive prevention, early detection and containment.
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13.11.​2025,

SNSF Starting Grants and Ambizione Fellowships

Information for Interested Parties 

Aquascope

Real-time underwater imaging

Research Projects

Investigation of the Resilience and Adaptability of Quagga Mussels

Epigenomics of rapid adaptation in invasive Quagga mussels
A multi phase research program by Eawag and the Swiss Federal Office for the Environment (FOEN)

Climate Change and Freshwater Biodiversity
Together with climate change, biodiversity loss is the most pressing environmental crisis of our time. The "Translational Centre Biodiversity Conservation" bundles knowledge and makes it generally available. In collaboration with key Swiss stakeholders, the Centre identifies topics for knowledge exchange, translation, and synthesis, and communicates and distributes the resulting synthesis products.

Translational Centre Biodiversity Conservation (TCBC)
The architecture of community structure, functional traits and trophic networks across blue-green ecosystems

Architecture of blue-green communities
Dieses Projekt leistet einen Beitrag zur Blue Green Biodiversity Research Initiative - einer Eawag-WSL-Kollaboration, die sich auf die Biodiversität an der Schnittstelle von aquatischen und terrestrischen Ökosystemen konzentriert.

Warming-related community turnover in terrestrial and freshwater ecosystems
Why do toxic cyanobacteria bloom? A gene to ecosystem approach...

Cyano Bloom
Understanding and measuring how flow intermittency drives biodiversity and river functions in an alpine environment

Alpine Streams and Flow Intermittency
An Eawag-WSL collaboration focusing on Biodiversity at the interface of aquatic and terrestrial ecosystems.

Blue Green Biodiversity Research Initiative

More current Research Projects

Latest publications

Müller, T., Hofstetter, L., & Spaak, P. (2025). Wie lässt sich die Ausbreitung der Quaggamuschel stoppen?. Vierteljahrsschrift der Naturforschenden Gesellschaft in Zürich, 170(2), 4-8. , Institutional Repository

Seit etwa 10 Jahren ist die Quaggamuschel nun in der Schweiz. Sie ist eine der einflussreichsten invasiven Arten in unseren Seen, und sie ist auch zunehmend in den Medien als wichtiges Thema präsent. Trotz der grossen Aufmerksamkeit bleiben viele Fragen zur Quaggamuschel bis heute offen und eine praktikable Methode, die Muschel wieder loszuwerden, ist nicht in Sicht. Verschiedene Schweizer Gewässer sind aber bis heute verschont geblieben. Diese Gewässer gilt es nun so lange wie möglich zu bewahren.
Ferraz, M. A., Rezende, R. S., de Omena, P. M., Costa, L. C., Oester, R., Bruder, A., & Moretti, M. S. (2025). Upstream deforestation and nonnative crops affect leaf breakdown and aquatic invertebrate assemblages in streams. Freshwater Biology, 70(10), e70102 (13 pp.). doi:10.1111/fwb.70102, Institutional Repository

1. Stream ecosystem functioning and community structure are influenced by local and catchment land use. In mosaic landscapes, agricultural activities can also affect leaf breakdown and detritivore assemblages in downstream forest reaches.
2. We evaluated the combined effects of upstream deforestation and the input of a nonnative crop species on leaf breakdown and associated invertebrate assemblages within forest reaches. We incubated the leaves of banana trees (Musa spp.) and the native tree species Miconia chartacea in eight streams under both single-species and mixed-species treatments. The studied reaches were located upstream of the deforested areas in half of the streams and downstream of the deforested areas in the second half. We tested whether (i) crop leaves influence the leaf breakdown of native leaves and leaf colonisation by aquatic invertebrates and (ii) whether upstream deforestation exacerbates the effects of crop leaves on these processes.
3. In both reach types, M. chartacea monocultures had the highest breakdown rate, followed by M. chartacea exposed in mixtures, Musa spp. exposed in mixtures, and Musa spp. monocultures. All leaf treatments decomposed more slowly in downstream forest reaches, with mass losses 17.8%–8.7% lower than the mass loss of M. chartacea monocultures in upstream forest reaches. The invertebrate richness and density, shredder density, and scraper density did not differ among leaf treatments or reach types. The abundances of collector-gatherers were positively correlated with the mass loss of M. chartacea and Musa spp. In the downstream forest reaches, the calamoceratid shredder Phylloicus and the hydropsychid collector-filterer Smicridea were positively correlated with overall leaf mass loss.
4. Our study showed that upstream deforestation may cause alterations in the taxa distributions of invertebrate assemblages with consequences on leaf breakdown rates in forest reaches. These effects however strongly depend on the characteristics of the leaves and of the detritivores (i.e., their identity).
Khaliq, I., Lavender, E., Kamran, H., Shahid, M. J., Sheraz, M., Awais, M., … Hof, C. (2025). Variation in ectotherm thermal tolerances with elevation and temperature across biological scales. Global Ecology and Biogeography, 34(10), e70135 (12 pp.). doi:10.1111/geb.70135, Institutional Repository

Aim: Variation in thermal tolerances along environmental gradients is assumed to follow similar patterns across different biological scales, including within and between species, and across communities. However, this assumption has yet to be tested using comprehensive datasets collected through standardised methodologies.
Location: Southern Asia.
Time period: 2017–2019.
Major taxa studied: Ants, beetles, grasshoppers, and spiders.
Methods: We quantified the associations between thermal tolerance traits and elevation or temperature at three biological scales (community, broad taxonomic group, and species) along two distinct elevational transects in Southern Asia. In total, we measured thermal tolerances of over 15,000 individuals from 114 arthropod species belonging to four invertebrate taxa (ants, beetles, grasshoppers, and spiders). We compared the relationships at each scale using mixed-effects models.
Results: At the community scale, across all individuals of all species, we found a consistent decline in the values of three thermal tolerance traits (upper tolerance, lower tolerance, and tolerance breadth) with elevation along the Himalayan transect but an increase in the values of upper and lower tolerance along the Sulaiman transect. The relationships of thermal tolerance traits and elevation/temperature varied among the groups and species between the Himalayan and Sulaiman transects. This suggests that factors beyond elevation, including vegetation composition, microclimate, landscape features, and local adaptation, drive observed variation in thermal tolerance traits among and within species.
Conclusion: Our study highlights the interplay between thermal physiology and the environment across different habitats and biological scales. Our findings indicate that predicting biodiversity responses to environmental change based on thermal tolerance–environment relationships requires careful consideration of group- and species-level variation. This is essential for improving the accuracy of climate change impact assessments on biodiversity.

Further publications