The freshwater ecosystem in the Mediterranean Coast Network includes perennial and ephemeral streams, springs and seeps. Science and resource management activities focus on the conservation challenges facing freshwater resources in a human-influenced landscape. For example, in the Santa Monica Mountains, urbanization has led to large-scale changes in stream hydrology, morphology and water quality in many streams as well as facilitated the introduction and spread of non-native species, such as crayfish. These changes have enormous impacts on native aquatic amphibian populations. As a result, the Santa Monica Mountains National Recreation Area has begun monitoring amphibians as an indicator of ecosystem health.

^IN biological inventory project
^VS ecosystem vital sign monitoring project