CDFW and Robinson Rancheria Partner on Pilot Program to Remove Invasive Carp, Goldfish to Help Clear Lake Hitch

By: KATHERINE M. CLEMENTS

The California Department of Fish and Wildlife (CDFW) and the Robinson Rancheria Pomo Indians of California (Robinson Rancheria) announced on Feb. 14 that they have initiated a pilot program on Clear Lake to remove invasive carp and goldfish to benefit the Clear Lake hitch, also known as “Chi.”

The Clear Lake hitch or Chi is a large, native minnow found only in Clear Lake and its tributaries within Lake County. Since 2014, the fish has been classified as threatened under the California Endangered Species Act. A vital cultural resource for Native American tribes within Lake County, Clear Lake hitch populations used to be seen in runs numbering in the tens of thousands.

Through permitting and $177,872 in grant funding from CDFW, the Robinson Rancheria is leading the pilot research effort to study the effectiveness and benefits of removing nonnative carp and goldfish from Clear Lake.

The Robinson Rancheria contracted with the Minneapolis-based WSB engineering and environmental consulting firm to seine sections of Clear Lake from Feb. 3 - 11, to catch carp and goldfish. Some of the carp and goldfish were kept for biological testing, but most of the fish, including all nontarget sport fish, were returned to the lake unharmed as part of the feasibility study.

The timing of the project was chosen to coincide with the period when carp and goldfish form large aggregations in preparation for spawning for a more efficient collection of target species and to minimize bycatch of other fishes. CDFW was on the water monitoring the effort. Other partners include the Big Valley Band of Pomo Indians and the Lake County Water Resources Department. Carp and goldfish are detrimental to Clear Lake hitch and their habitat in several ways, including predating on Clear Lake hitch eggs, disturbing and circulating nutrients in the lake that can reduce water clarity and foster harmful algal blooms in the summer, and inhibiting tule growth. In addition, tule provides essential rearing habitat for juvenile Clear Lake hitch.