Introduced Fish in Mountains: State of Published Research on their Removal from Lentic Ecosystems

The introduction of alien fish in freshwater ecosystems has become an increasing concern over the last decades and a considerable amount of literature exists on their ecological consequences. However, less is known about their management and eradication, particularly in mountain ecosystems, where fish introductions have been carried out over decades. Here, we systematically mapped and reviewed peer-reviewed literature on fish removal in mountain ecosystems, with a focus on standing waters. The results of our work indicate important spatial and taxonomic biases, with most published studies performed in North America and on salmonids. The removal methods were primarily physical (57%) and chemical (31%), with variable success rates depending on which approach or combination of approaches were used, the species targeted, and ecosystem characteristics. Based on the 35 publications we reviewed, there is no "silver bullet" for fish removal from mountain standing waters. Prevention, early detection, and rapid intervention remain the best approach in halting the spread of or eradicating invasive species before the establishment phase. Making use of the available data and learning from past interventions remains the most affordable approach to guide and adapt management options. To share the knowledge we collected, inform management, and raise awareness, we developed the "FishME Toolbox" as an online open access infrastructure offering tailored resources for both expert and non-expert users.