Biology Professor Chris Lowe and graduate student Tom Mason collaborated with University of California, Santa Barbara biologist Jenn Caselle to evaluate the site fidelity, habitat use and home ranges of four of Southern California’s highly prized sport fish by tagging and tracking them using acoustic telemetry. Information learned from this study will assist the California Department of Fish and Game in identifying areas and sizes of marine reserves that can protect reproductively important adults among these popular sport fish as the Marine Life Protection Act is implemented in Southern California.
Research was conducted in the Catalina Island Marine Science Center Marine Life Refuge involving the California sheephead, kelp bass, barred sand bass and ocean whitefish. The movements of eight barred sand bass, 19 kelp bass, 19 ocean whitefish and 18 sheephead were monitored for a year to evaluate their fidelity to the 20-year-old Catalina no-take marine reserve.
To estimate site fidelity to the reserve, researchers measured the number of days each fish was detected within the refuge over the course of a year. Biologists
measured the nocturnal and daytime activity levels of the ocean whitefish and barred sand bass and the distances these species traveled per day. Then researchers captured, tagged and moved fish to other locations outside the reserve to determine their inclination to cross expanses of sand and/or mud to return home.
The scientists also analyzed the habitat preferences of the four species. Surprisingly, they discovered that edge habitats—where rocky areas transition to sand or mud—are important for all four species. Therefore, this kind of habitat is essential for effective marine reserves. To reduce the capture rates of these four heavily fished species, the biologists recommend placing reserve boundaries at least 100 meters away from rocky habitat edges.
The group concluded that kelp bass and barred sand bass, both ambush predators, have smaller home ranges than ocean whitefish and sheephead, which forage on small invertebrates along the bottom. Hence, small marine reserves are more likely to protect these types of bass than ocean whitefish and sheephead.
