Studying Threatened Fish Species in Clear Lake, CA

Science Center Objects

A fish species known as the Clear Lake Hitch, presently listed as threatened under the California Endangered Species Act, is now being considered by the U.S. Fish and Wildlife Service for placement on its endangered species list. The hitch 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 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. Research will also be conducted to determine how fish embryos might have a better chance of survival.

Fish - Clear Lake Hitch

Close-up image of Clear Lake Hitch


The Water Science Center team will identify the distribution of spawning sites throughout the lake and its tributaries, noting the characteristics of each. Part of this will include comparing the survival rates in each area. The team will also utilize egg incubation trays for research and as a possible means of repopulating the species.

Science Plan

Spawning areas will be checked and measured each week during the 2018 spawning season. Experiments will be conducted to compare embryo survival rates across these areas. An experiment will also be conducted to determine the effect of egg incubation trays on embryo survival.