CSUN Professor’s Research Could Have Implications for California Fishermen
On average, buying white seabass from the local market will cost you $20 to $35 a pound. Twenty-seven years ago, that wasn’t the case. In the 1980s, over-fishing of white seabass depleted California’s coastal waters of the fish, forcing its market price to skyrocket.
As the fish population started rebounding in the mid-1990s, California State University, Northridge biology department chair and professor Larry Allen began a study along the Southern California coast in the Channel Islands, San Diego and Santa Barbara, focusing on the white seabass (Atractoscion nobilis).
Allen, biologist Edwin Leung — a CSUN alumnus — and a team of researchers measured year class strength, a summary of the reproductive success of a species from a given year, to determine its relationship to the catches from recreational and commercial fishing.
Their published findings in the Journal of the California Department of Fish and Wildlife could potentially save the fish from fishery extinction and provide a more sustainable, price-balanced economic commodity for the public.
“Promoting sustainability is the way to avoid over-harvesting, and it has an economic importance,” Allen said. “Measuring and studying how successfully the white seabass reproduce over the years helps promote sustainability, because you’re able to sustain the fishery over longer periods of time by taking the correct amount of fish.”
In order to calculate the age of white seabass, the scientists sectioned their ear bones (otoliths) and counted the rings found in them that reflected the age of the fish. From the age structure of samples, the year class strength was determined and compared to the commercial fishery landings over a 15-year period.
The study concluded that the year class strength significantly predicted commercial landings of white sea bass 11 years later. Therefore, it takes 11 years to grow to the size where they can enter the fishery and can be sold in the market.
With more than a decade of lagging, this tight relationship helped the researchers predict how successful future catches would be, based on how many fish are in each “year class,” or age group.
“California fisheries’ managers can now predict commercial landings of white sea bass based on how many babies survived 11 years earlier,” Allen said. “We found that by sampling the younger stages, such as the 1, 2 and 3-year-olds quantitatively, we could easily estimate their year class strength.
“People can catch more fish when these strong year classes are coming through,” he continued. “Managers also can predict when the catches may start declining — you can monitor it in an effort to prevent over-fishing, by matching how many fish survived their first year versus how many the recreational and commercial fishermen are taking 11 years later.”
What the CSUN research team learned may lead to good news at the seafood counter when visiting your local market, in the not-too-distant future.
For more information on the study, please contact larry.allen@csun.edu.