Sportfishes Thrive in La Jolla Marine Reserve
Christina Johnson
SeaGrant California UCSD
09/10/2008
According to results of a four-year diver survey, prohibiting fishing in the marine reserve at the La Jolla Cove has created a haven for sportfishes..
UC San Diego marine biology professor Phil Hastings, who led the survey, also reports finding the highest density of kelp bass recorded in the Southern California Bight in the last four decades in the reserve.
The results are especially noteworthy given the relatively small area of the San Diego-La Jolla Ecological Reserve, only 210-hectares, or .81 square miles.
“We were really surprised by our results,” Hastings said. “We knew the La Jolla reserve protects important fish habitats but we did not necessarily expect to see measurably higher numbers of reef fishes. Our results tell us the reserve should receive continued and really even expanded protection from fishing.”
For the project, which was funded by California Sea Grant, divers swam set 50-meter transects at multiple depths in the reserve, at an adjacent site known as Boomers and at a control site off Palos Verdes in Los Angeles and counted the numbers of each species of fish observed. Boomers is a shallow reef area known for its pounding surf, hence its name, and is not heavily fished. The area off Palos Verdes has high-relief reef and kelp forest similar to that of La Jolla but is heavily fished.
In all, about 252 transects were swum within the reserve, 248 at Boomers, and 188 at Palos Verdes for the four-year period beginning in 2002. On these, divers counted 52,520 fish at the reserve, 41,330 at Boomers and 16,080 at Palos Verdes. Fifty-two species were counted at the reserve, compared to 50 species at both Boomers and Palos Verdes.
Not only was the diversity of fish life comparable at all three sites but so was the relative abundances of species. Eight of the twelve most common species were the same at all three sites, as were the two most common species, blacksmith (Chromis punctipinnis) and senorita (Oxyjulis californica).
“The main difference between the sites is that Palos Verdes has fewer fish,” Hastings said, particularly of two of the region’s most popular sportfish, California sheephead (Semicossyphus pulcher) and kelp bass (Paralabrax clathratus)...
