Lake Ecology

The Sierra Nevada contains thousands of lakes and ponds. Despite their importance to wildlife and people, until recently they were relatively little-studied. As a consequence, the species inhabiting these water bodies, structure of lake food webs, and impacts of fish introductions were all poorly understood. We’ve sought to remedy this using landscape-scale surveys, detailed observational studies, and whole-lake experiments. 

In the late 1990s and early 2000s, we surveyed more than 7,000 lakes and ponds in the central and southern Sierra Nevada. We used data collected in this survey effort to describe these habitats and their species composition, including native amphibians, benthic macroinvertebrates, and zooplankton, and non-native fish. This information and subsequent studies allowed description of the effect of non-native fish on lake fauna, the recovery of this fauna following fish removal, impact of changes to lake communities on the adjacent terrestrial ecosystem, and the effect of mountain yellow-legged frog extinctions on lake ecosystems. 

The findings from our research provide the foundation for lake recovery efforts being implemented in the Sierra Nevada by the National Park Service, U.S. Forest Service, and California Department of Fish and Wildlife. These efforts will ensure that sufficient numbers of lakes remain in their original fishless condition to support viable populations of native species.