Wetland fish in peril: A synergy between habitat loss and biological invasions drives the extinction of neglected native fauna

Abstract

European wetlands, crucial freshwater ecosystems, face multiple anthropogenic threats. For native wetland fish species (NWFS), habitat degradation and the spread of invasive non-native species (INS) are the most important, and place NWFS at increasing extinction risks. This perspective study examines the impact of these combined threats on the NWFS. Four characteristic species with the largest distribution area in the European Union were evaluated, which share the habitat requirements and susceptibility to these impacts – crucian carp (Carassius carassius), European weatherfish (Misgurnus fossilis), sunbleak (Leucaspius delineatus) and mudminnow (Umbra krameri). Here, we investigated how the interplay of habitat loss and biological invasions impacts the population and conservation status of these species. This study seeks to stimulate more conservation-oriented research leading to cross-border cooperation on conservation status monitoring and repopulation programmes. Improved knowledge of impacts and mechanisms of habitat loss and interspecific interactions with INS is vital for safeguarding the remaining populations of NWFS, allowing for repopulation measures with genetically suitable individuals in severely impacted areas.