Studying Threatened Fish Species in Clear Lake, CA
The Clear Lake Hitch (Lavinia exilicauda chi) population, which once flourished in great abundance, has been decimated by loss of spawning habitat, nursery areas, and the encroachment of non-native species. In order to make an informed decision, the California Water Science Center has been asked by the U.S. Fish and Wildlife Service to conduct studies into the fish’s habitat, specifically changes to spawning areas, such as the lake’s tributaries, and shorelines where juvenile fish mature.
The Clear Lake Hitch was formerly highly abundant and a staple food for the Pomo tribes of the Clear Lake region. The abundance of this fish species is unknown but is believed to have declined 100-fold. USGS biologists have learned a great deal about this endangered fish, from identifying important spawning tributaries, to documenting how fish use different habitat throughout their life cycle.
Beginning in 2017, biologists from the U.S. Geological Survey began studying the lake habitat of the Clear Lake Hitch, a minnow that is listed as a threatened species under the California Endangered Species Act. The hitch is now being considered by the U.S. Fish and Wildlife Service for classification under the Endangered Species Act.
To better understand Clear Lake Hitch behavior and habitat use, USGS biologists have conducted extensive sampling of the lake itself, as well as detailed analysis of various parts of the fish, including otoliths (ear bones), eye lenses, and fish muscle. These findings are important for identifying critical habitat, an important element of endangered species conservation and management.
The Clear Lake Hitch has an interesting life history in that it lives within Clear Lake but migrates upstream into streams like salmon, to spawn during the spring. Catch of Clear Lake Hitch during summer sampling has decreased each year, with the fewest number of individuals encountered occurring in 2022.
The USGS is working closely with the U.S. Fish and Wildlife Service to generate additional scientific information needed for effective management and conservation of this imperiled species.
Hydrologic and Aquatic Ecology Studies at Clear Lake, California
Detection range and efficiency of acoustic telemetry receivers in Clear Lake, Lake County, California
Abundance and Distribution of Clear Lake Hitch in Clear Lake, Lake County, California, 2017-2022 (ver. 4.0, December 2022)
Water Temperature of Selected Tributaries of Clear Lake, Lake County, California
Water Quality Vertical Profiles in Clear Lake, Lake County, California, 2017-2023 (ver. 4.0, May 31, 2024)
Photographs and video clips of Clear Lake Hitch
Clear Lake Hitch Otolith Data
Eye lenses reveal ontogenetic trophic and habitat shifts in an imperiled fish, Clear Lake hitch (Lavinia exilicauda chi)
First record of pughead deformity in the threatened Clear Lake Hitch
Observations of the spawning ecology of the imperiled Clear Lake Hitch Lavinia exilicauda chi
Dissolved oxygen controls summer habitat of Clear Lake Hitch (Lavinia exilicauda chi), an imperilled potamodromous cyprinid
Strontium isotopes reveal ephemeral streams used for spawning and rearing by an imperiled potamodromous cyprinid--Clear Lake hitch Lavinia exilicauda chi
The Clear Lake Hitch (Lavinia exilicauda chi) population, which once flourished in great abundance, has been decimated by loss of spawning habitat, nursery areas, and the encroachment of non-native species. In order to make an informed decision, the California Water Science Center has been asked by the U.S. Fish and Wildlife Service to conduct studies into the fish’s habitat, specifically changes to spawning areas, such as the lake’s tributaries, and shorelines where juvenile fish mature.
The Clear Lake Hitch was formerly highly abundant and a staple food for the Pomo tribes of the Clear Lake region. The abundance of this fish species is unknown but is believed to have declined 100-fold. USGS biologists have learned a great deal about this endangered fish, from identifying important spawning tributaries, to documenting how fish use different habitat throughout their life cycle.
Beginning in 2017, biologists from the U.S. Geological Survey began studying the lake habitat of the Clear Lake Hitch, a minnow that is listed as a threatened species under the California Endangered Species Act. The hitch is now being considered by the U.S. Fish and Wildlife Service for classification under the Endangered Species Act.
To better understand Clear Lake Hitch behavior and habitat use, USGS biologists have conducted extensive sampling of the lake itself, as well as detailed analysis of various parts of the fish, including otoliths (ear bones), eye lenses, and fish muscle. These findings are important for identifying critical habitat, an important element of endangered species conservation and management.
The Clear Lake Hitch has an interesting life history in that it lives within Clear Lake but migrates upstream into streams like salmon, to spawn during the spring. Catch of Clear Lake Hitch during summer sampling has decreased each year, with the fewest number of individuals encountered occurring in 2022.
The USGS is working closely with the U.S. Fish and Wildlife Service to generate additional scientific information needed for effective management and conservation of this imperiled species.