Department Fish Ecology and Evolution

The ability to halt biodiversity loss and effectively protect habitats fundamentally depends on correctly identifying species and comprehensively describing biological diversity. Taxonomy plays a crucial role in this effort, as it focuses on the recognition, classification, and understanding of biodiversity. Until now, approximately one-fifth of the more than 120 fish species known to occur in Switzerland are still awaiting formal description. Understanding fish diversity, defining their geographical boundaries and habitat requirements, and assessing current threats are essential for their protection. As part of the LANAT-3 project, target fish groups such as stone loaches (Barbatula spp.), minnows (Phoxinus spp.), sculpins (Cottus spp.), gudgeons (Gobio spp.) and others are being studied, their identification resolved, and new species described (Calegari et al. accepted). Accurate identification and classification of these species are key to legal protection and enable appropriate conservation planning and efforts (Josi et al. 2024a).

Both natural factors, like climate and food availability, and human activities affect the distribution of species. Here, ecological niche models are used to predict where species are likely to be found, but these models don’t explain why certain areas are suitable or not (Josi et al. 2024b). Therefore, a new approach has been developed in this project using Explainable AI to help identify which environmental factors make a habitat good or bad for a species at a given location. This makes it possible to quantify the extent of human activity on a species’ natural habitat and identify the key factors driving loss of species in a given area (Waldock et al. 2024). These insights help designing targeted conservation measures to protect aquatic biodiversity (Wegscheider et al. 2024).

Although Switzerland has legal and strategic frameworks for aquatic biodiversity conservation, their implementation faces numerous challenges, including limited resources, opportunistic rather than evidence-based approaches, conflicting objectives, and insufficient collaboration among key stakeholders. To overcome these issues, close cooperation between science and practice is essential, along with the implementation of adaptive and integrated management. Socio-ecological network analysis help the project to assess how well institutions collaborate internally and with each other, identifying areas for improvement (Zinn et al. 2024). Additionally, participatory processes bring together relevant stakeholders to jointly identify evidence-based, practicable strategies and measures for the effective and efficient conservation and restoration of aquatic biodiversity in Switzerland. Initial insights were gained from the test region (Aeschlimann et al. 2024a; Aeschlimann et al. 2024b) and are further elaborated in the pilot region, where conservation and restoration needs are particularly high, to ultimately generate learning for entire Switzerland.