Spatial priorities for freshwater fish conservation in relation to protected areas

Abstract

Abstract1. Freshwater habitats are vital for both humans and nature owing to theirexceptional biodiversity and valuable ecosystem services, but they are currentlyfacing serious threats. The designation and management of protected areas havebeen proposed as the most feasible way to ensure conservation objectives for thefuture. However, traditional approaches have not protected freshwater faunaeffectively, especially freshwater fish.2. Previous studies have identified the most irreplaceable terrestrial places toachieve conservation goals. Here, the aim was to investigate how the presentnetwork of protected areas preserves irreplaceable rivers for freshwater fish.3. The irreplaceability of the world's river basins was calculated using InternationalUnion for the Conservation of Nature Red List distribution maps, considering therarity, richness, and conservation status of their freshwater fish fauna. Theoverlap between irreplaceable basins and the present network of protected areaswas also calculated.4. The results highlight the conservation significance of tropical rivers, particularlythose in the Neotropics. The subset of the basins covering 30% of the mostirreplaceable land surface (in line with the United Nations 30by30 target)encompasses 99% of freshwater fish species. However, protected areas do notseem to provide sufficient protection to these basins, as 89% of their surface arealies outside protected areas. Only 7% of freshwater ecoregions meet the UnitedNations 30by30 target.5. Given the context of climate change, allocating new protected areas becomescrucial in providing better survival opportunities for freshwater fish species.Despite the limitations inherent to the absence of total knowledge of freshwaterfish biogeography and the irreplaceability index itself, this study identifies prioritysites for their conservation that may help inform decision-making in the future toestablish more effective protected areas.