Protection of Aquatic Biodiversity in California: A Five‐tiered Approach

Aquatic biodiversity is being lost at an even more rapid rate than terrestrial biodiversity, especially in arid regions such as California. In the United States, it is increasingly obvious that the Endangered Species Act of 1973 (ESA) cannot adequately deal with this loss. To help solve this problem, we have developed a five‐tiered approach for aquatic conservation in California that should be applicable to other regions as well: (1) immediate ESA listing of species likely to be extirpated in the next 20 years; (2) implementation of restoration‐oriented management strategies for clusters of declining species that inhabit the same habitats or drainages; (3) creation of a system of drainages and habitats called Aquatic Diversity Management Areas that provides systematic, statewide protection of aquatic biodiversity; (4) designation of a system of key watersheds, starting with seven pilot watershed projects that represent a diversity of challenges; and (5) development of schemes for bioregional landscape management. If this approach, or one like it, is not adopted soon, extinction rates of aquatic organisms in California most likely will accelerate. The hierarchical approach to conservation proposed here, with its focus on watersheds as the most practical unit of aquatic conservation, should have widespread applicability.