California Halibut Trawl Surveys

The goal of this study is to develop a fishery-independent index of juvenile California Halibut abundance. The index can be used to inform management on the status of the resource, and provide predictions for recruitment to the fishery in southern California. Because juvenile halibut spend their first couple of years exclusively in shallow offshore locations and embayments, conducting mark-and-recapture trawl surveys can be used to evaluate distribution, relative abundance and expected contributions to the fishery. 

Starting in April 2018, SCFRMP staff began conducting biannual trawl surveys in the spring and fall months using a 25 ft. otter trawl. Trawls are deployed in 11 primary locations ranging from San Diego to Los Angeles. Ten 10-minute trawl surveys are conducted in 8 to 20 ft. depths at each location, and all of the fish caught are identified and measured. All halibut greater than 3 inches are internally tagged with a Passive Integrator Transponder (PIT) tag that allows for identification of specific individuals when recaptured. The number of halibut per area is calculated to determine a relative index of abundance. This fishery-independent index of abundance will be compared to past surveys as well as across years to help inform the status of the fishery. 

CDFW staff sample CA Halibut