Conserving Freshwater Biodiversity in U. S. Protected Areas – Management Intervention and the RAD Framework

05 February 2026
Map of federally designated protected areas in the United States relevant to freshwater biodiversity, with colors indicating different federal land designations.
Map of federally designated protected areas in the United States with the greatest potential to benefit freshwater biodiversity. The protected areas shown are those commonly managed for natural character and biodiversity at the national level. Note that this map excludes designations managed by the National Parks Service whose management is unrelated to ecological or biodiversity conservation (e.g., National Battlefields, National Parkways, National Historic Sites, etc.).

23 December 2025

Abstract

Protected areas are considered a critical antidote to global biodiversity loss. Yet, protected areas have not effectively preserved freshwater biodiversity compared to other taxonomic groups, in part because they are not designed or managed with freshwater ecosystems in mind. Additionally, historical and current human activities have degraded freshwater biodiversity, and climate driven transformation constrains the ability of protected areas to preserve freshwater biodiversity into the future. Management intervention is an important tool to ensure protected areas support current and future ecological, socio-cultural, and economic values surrounding freshwater biodiversity. Yet applying interventions is challenging because many protected areas limit human manipulation and control. The Resist-Accept-Direct (RAD) framework is a tool for weighing management approaches in an expanded decision space. As such, the RAD framework may help identify the most appropriate approaches to address ecological transformation while balancing the mandates and values of a given protected area. In this paper, we review federally protected areas of the United States and their varied ability to support freshwater biodiversity. We then recast past management approaches through a RAD lens, examining how they resist, accept, or direct freshwater biodiversity loss in these protected areas. This illustrates how elements of the RAD framework are already being applied and provides a foundation for managers to more formally resist, accept, or direct freshwater biodiversity loss in protected areas moving forward. We conclude with considerations for applying the RAD framework at the intersection of freshwater biodiversity and protected areas to benefit values of current and future generations.

Citation

Kellie J. Carim, Hannah Adkins, Remi Murdoch, Leah Simantel, Andrea Stephens, Matthew Webster, Kira Hefty & Lisa A. Eby. Conserving Freshwater Biodiversity in U. S. Protected Areas – Management Intervention and the RAD Framework, Environmental Management 76 (2026):