National parks as protected areas for U.S. freshwater fish diversity

We assessed the representation of freshwater fish diversity provided by the National Park Service (NPS) and the potential for parks to serve as freshwater protected areas (FPAs) in the United States. Although most parks were not designed with freshwater conservation in mind, nearly two-thirds (62%) of native U.S. fishes reside in national parks. However, only 18% of the nation's highly imperiled fish species are represented within the NPS. The ability for parks to serve as protected areas depends on activities upstream from their boundaries and we found that a substantial part of these watersheds has some form of conservation status. Using a conservation planning approach that integrates fish diversity representation provided by parks and their current and future ecological threats (i.e., climate change, dams, watershed impervious surface, invasive species) and management challenges (i.e., land stewardship beyond park boundaries), we identify 50 parks that could serve as core members of a nationally comprehensive FPA system. While the NPS has limitations as the potential basis for an FPA network, it provides considerable representation of freshwater fish diversity that should be taken into account during systematic conservation planning for freshwaters.