Socio-ecological effects of Fish removal in Mountain Lakes (FishME)

Mountain ecosystems worldwide face multiple threats arising from global change and its interactions with socio-cultural, economic and political developments. Mountain aquatic ecosystems, despite being one of the most important drinking water resources for the human population, also represent biodiversity hotspots in generally sparse high-elevation landscapes. Recent fish introductions put pressure on these ecosystems and the use of small fish such as minnow (Phoxinus phoxinus) is causing a new invasion wave. There is little information about the ecological impact, a desolating scenario, where many lakes will lose nearly all of its natural biodiversity, is depicted. The overarching hypotheses of FishME are (a) that fish introductions are detrimental not only to native biotic communities and their trophic interactions, but also to ecosystem functioning, and (b) that these adverse effects are reversible. The three main questions asked by FishME are: What are the societal and socio-economic motivations for fish stocking in mountain lake? Which are the impacts of fish stocking in different mountain regions considering the future trajectories of aquatic communities based on ongoing invasion processes and global change scenarios? What are the possible management and conservation options to reverse the detrimental effects of fish introductions on aquatic and semiaquatic biodiversity in the different mountain regions? FishME will draw on available data from projects the consortium members have been involved in and will supplement this data with data from 50 lakes along elevational gradients in the French, Spanish Pyrenees, the Italian and Austrian Alps, as well as the Romanian South Carpathians. The work, structured into four work packages will be synthesized in a FishMe Management Toolbox, a decision-support tool for regional conservation policy-making, including tools for predicting eradication efforts and probabilities.