New study to track San Diego’s top trophy fish

The researchers will be tagging and tracking the species – so-named for its distinctive yellow tail – to learn more about how far these animals travel along the coast, where they go and the amount of mixing between different populations.

“We are excited to be conducting research on a species that is so coveted in San Diego, and yet has not been studied recently,” Sandin said.

According to the scientists, there has been little basic research on the species’ life history characteristics off California since 1960, when the last comprehensive peer-reviewed study was published.

The tagging and tracking data that will be gathered in this project will focus on two main questions to ensure the sport fishery’s long-term sustainability:

1) whether there is a resident year-round yellowtail population in San Diego,

2) whether these fish are successfully spawning locally.

Anglers report seeing yellowtail, also known as mossbacks or jacks, year-round in La Jolla kelp forests. “They call them ‘home guards,'” said Ben-Aderet, a marine biology doctoral student in the Sandin lab.

Fishermen also say they see adult yellowtail congregating at the surface in summer, which suggests the animals may be aggregating to spawn. Owyn Snodgrass, a research biologist at NOAA Southwest Fisheries Science Center in La Jolla, who is a collaborator on the project, said that it’s possible yellowtail are spawning offshore locally or even inshore in kelp beds.

“We see large females in the kelp beds,” he said. “We may have a local stock that is more adapted to [colder] local conditions.”

The prevailing scientific view has been that yellowtail, known in science circles as Seriola lalandi, is a subtropical species that migrates from southern California to central Baja California, Mexico when local ocean water temperatures drop below about 64 degrees Fahrenheit. Local spawning has never been documented.

Beginning this summer, Ben-Aderet will be going out with anglers on sportfishing charter boats such as the new Lo-An to tag and release yellowtail. The scientists also plan to hold two month-long tag-and-release tournaments, one this winter and one in the summer of 2014, to further engage the community in research and to encourage them to report recaptured tags on caught fish.

“You can’t manage a species if you don’t know its basic biology, ” said Captain Markus Medak of the New Lo-An, explaining his interest in participating in the collaborative fisheries research. “The average size of fish has gone down. I think it’s a fairly healthy fishery, but you don’t want to wait for it to crash before you begin to really manage it.”

California Sea Grant at Scripps Institution of Oceanography, UC San Diego is administering this research project on behalf of Collaborative Fisheries Research West.