Great White Sharks Among
82 Fish Facing Extinction

Glen Martin, Chronicle Staff Writer
Thursday, November 2, 2000

The report concludes that many California fish generally thought of as common are at particularly grave risk, including great white sharks and several species of rockfish.

Environmentalists say the study, which appears in the current issue of Fisheries, a peer-reviewed scientific journal published by the American Fisheries Society, demonstrates an immediate need for an extensive marine refuge system where fishing would be permanently banned.

``The big message from this is that we have the power to permanently remove large numbers of species from the oceans,'' said Kate Wing, an ocean policy analyst with the Natural Resources Defense Council.

``We think the ocean is so vast that we can't exterminate its (fish), but that's precisely what we're doing.''

In all, the report identifies 82 species of marine and estuarine fish living in the waters off Canada, the United States and Mexico that are in danger of extinction. Overfishing was the root cause of the threat in most cases, followed by habitat destruction and pollution.

The report has special significance for California, which supports one of the richest and most biologically diverse marine fisheries in the world. The data was particularly ominous for rockfish, a complex of bottom-dwelling food and sport fish that number in the scores of species.

Twelve rockfish of the genus Sebastes were listed as threatened with extinction, along with lingcod, another botton-dwelling fish noted for its large size, ferocious fighting ability and succulent flesh.

Several sharks were also listed, including great white sharks and basking sharks, both found off California. Great whites are the largest piscine ocean predator, and are often observed killing seals and sea lions off the Farallon Islands near San Francisco and Ano Nuevo Island north of Santa Cruz.

Basking sharks are the second biggest fish in the world. Only whale sharks are larger -- and they also made the threatened list.

Four types of sturgeon were also listed, including the white sturgeon and green sturgeon, both found in San Francisco Bay.

The study is surprising, given that many of the listed species are popular in fish markets and with sport anglers. Rockfish and sturgeon are commonly caught by Bay Area fishermen.

Fish scientists say most of the listed species share common characteristics.

``They tend to be slow-growing. They're slow to reach sexual maturity. They have low fecundity. And that all means they tend to have low rates of population growth,'' said John Edward Olney, an associate professor with the Virginia Institute of Marine Science, which is associated with the College of William and Mary.

Olney said the misperception that many of the threatened fishes are common is due to ``occasional local pockets of abundance. But it's important to realize these are basically relict populations, residuals left from populations that were once much, much larger.''

Rebuilding populations of the depleted fish may be difficult, fisheries experts say, and will only succeed if there is long-term commitment.

``The Pacific Fishery Management Council (which establishes marine fishing regulations in federal waters) is working on a recovery plan for cow cod (a large Pacific rockfish), and they're figuring it will take 90 years because their populations are so low,'' Wing said. ``And at the end of that time, there's no guarantee the plan will work.''

Wing said it is imperative to establish marine refuges immediately. This, she said, will help stabilize current populations of threatened species.

``We basically need large reserves, areas where fishing is prohibited,'' she said. ``Marine refuges allow large numbers of fish to congregate in protected circumstances so they can breed successfully. They produce eggs and larvae that migrate outside the reserve borders, reseeding other areas.''

But some fishing industry advocates think other approaches might be better.

``Refuges are not going to help a lot of these stocks,'' said Zeke Grader, the executive director of the Pacific Coast Federation of Fishermen's Associations. ``They're everybody's favorite mantra right now. They might work for certain species of rockfish, but what we really need is a combination of good research followed by sound management practices.''

Grader said fish stocks should be ``proactively protected and rebuilt. That includes making sure we really have good information on the life histories of the (threatened species), and perhaps prohibiting certain types of activities, like heavy bottom trawling. We should also look at restoring habitat, like building artificial reefs where natural ones have been destroyed.''

E-mail Glen Martin at gmartin@sfchronicle.com.