Where do Halibut Go?

Brookhurst Marsh after restoration.

California Halibut are a commodity to sport and commercial fishermen in southern California. Coastal habitats that serve as fish nurseries and feeding grounds for California Halibut and other species have been drastically reduced in this area. MSRP and the National Oceanic & Atmospheric Administration (NOAA) provided funding to restore areas of the Huntington Beach Wetlands to full tidal exchange opening up more than 100 acres of new fish habitat. Following these restoration projects, MSRP and NOAA funded studies performed by a group of scientists and students from the California State University of Long Beach to understand how California Halibut spend their time in the wetlands.

To understand the small-scale movements of adult California Halibut and the importance of the wetlands to this fish species, scientists tracked fish using tags that send out sound signals. They found that adult California Halibut did not move into the newly restored wetlands but stayed in the tidal channel which runs along the edges of the marsh. This is probably because eelgrass beds which are important to adult California Halibut were not present in the wetlands at the time of the study.  Scientists did find juvenile or younger halibut inside the newly restored areas proving that this area is serving as a fish nursery providing food and shelter for smaller fish. Once eelgrass beds do start forming then adult halibut may start moving into the wetlands to feed as well.

Another interesting study that is currently taking place is to understand whether or not the same halibut are using neighboring wetland areas. This would suggest that these smaller restoration sites along the coast are providing enough

Juvenile Halibut in wetlands.

connection and habitat for fish species given the fact that over 90% of wetlands have been lost in this area.

The previous study was a unique opportunity for scientists to learn about recovery of fish in a restored wetland area that had been separated from ocean water for more than 100 years. Another notable observation from this study was that the number of fish, types, and diversity was similar to other wetlands after only one year since water first flowed into newly constructed channels. This is definitely good for California Halibut!

-Gabrielle Dorr, MSRP Outreach Coordinator