Department Surface Waters - Research and Management

Antimicrobial resistance (AMR) in aquatic environments is an emerging public health concern, yet environmental surveillance remains underdeveloped compared to human and animal sector. A harmonized European approach to AMR monitoring in aquatic environments is urgently needed due to lack of standardized methods, suitable indicators, reference materials, reporting, and data sharing mechanisms. This perspective paper presents insights from a pilot study, coordinated by the European Environment Agency (EEA), Eionet, and the European Topic Centre Biodiversity and Ecosystems (ETC-BE), aimed at testing the feasibility of harmonized monitoring of AMR in surface waters within regulatory-authority-led water monitoring structures. Ten countries participated, applying harmonized protocols for sampling, culture-based detection, qPCR analysis of antimicrobial resistance genes, and data reporting. The collaboration helped to build capacity and overcome technical barriers. The study demonstrated that harmonized environmental AMR monitoring is feasible and can be implemented consistently across countries and institutions, offering a path to obtaining critical insights into AMR sources, spread, and mitigation strategies. The pilot generated harmonized baseline data, validated methodological choices, and identified key challenges for large-scale implementation. Remaining challenges include the lack of standardized methods, quality criteria, and data infrastructure. Future efforts should focus on defining clear objectives, selecting relevant indicators, establishing environmental thresholds, and building capacity through collaboration. A harmonized European framework would support One Health integration, align with EU water legislation, and contribute to global AMR efforts. The findings underscore the importance of transitioning from fragmented research and ad hoc initiatives to coordinated, routine surveillance of AMR in aquatic environments.

Glacier retreat is rapidly transforming landscapes, creating thousands of new lakes that act as natural laboratories of ecological succession. In these newly formed ecosystems, colonizing animals must meet their requirements for essential organic nutrients, such as long-chain polyunsaturated fatty acids (LC-PUFAs). Here, we combined compound-specific stable isotope analyses of amino acids with fatty acid analysis to trace the origins and transfer of organic nutrients to fish (Arctic char) across a glacial-to-lacustrine lake succession in southern Greenland. Through lake succession, primary sources of nutrients shifted, coinciding with a 60% increase in LC-PUFA concentration in individual fish. In early glacial stages, Arctic char appeared to compensate for low LC-PUFA availability through endogenous biosynthesis of docosahexaenoic acid and, when connected to the fjord, by assimilating marine-derived nutrients via egg cannibalism. Overall, our results demonstrate that glacier retreat reshapes not only physical landscapes but also organic nutrient availability, with cascading consequences for animal physiology, ecosystem connectivity, and potentially long-term evolutionary trajectories.

Die Schweizer Seen erbringen eine breite Palette von Ökosystemdienstleistungen. Sie dienen als Nahrungsquellen durch Fischerei und Trinkwasserversorgung. Die meisten Seen sind reguliert und leisten einen wesentlichen Beitrag zum Hochwasserschutz. Seen dienen zunehmend als lokale und erneuerbare Energiequellen für Wärmenutzungen. Ausserdem sind sie wichtige Naherholungsräume für zahlreiche Freizeitaktivitäten und haben so einen grossen Wert für den Tourismus. Nicht zuletzt sind sie aber auch Hotspots der Biodiversität, welche zahlreichen bedrohten Organismen einen Lebensraum bieten. So beherbergen sie unter anderem eine grosse Anzahl endemischer Fischarten (Seehausen et al., 2022). 
Der fortschreitende Klimawandel ist für die Seen und ihre Ökosysteme eine grosse Herausforderung, deren Folgen sich in den kommenden Jahrzehnten verstärkt auswirken werden.