SAN FRANCISCO – A worldwide network of no-fishing zones may be the last, best hope of replenishing the Earth’s depleted stocks of fish and other marine species, an international team of scientists reports.

Fish, lobster and other species recover in only a few years given sanctuaries free of the hooks and nets of commercial and sports fishermen, the researchers say.

In a report released Saturday at the national meeting of the American Association for the Advancement of Science, they urged creation of the network of marine parks where all sea animals and plants would be protected.

Just as national parks provide safe haven for threatened animals on land, marine parks could be the salvation for vanishing ocean life, the study said.

“The oceans are more vulnerable than we realized,” said Jane Lubchenco, an Oregon State University marine scientist. “We know now that the present methods are inadequate to protect the oceans.”

Overfishing, pushed by a hungry world’s demand for seafood, has moved species of fish toward extinction, the scientists said, and permanent marine parks may be the only answer to save them.

“The seas are increasingly in serious trouble,” said Stephen Palumbi of Harvard University. He said dying coral reefs, toxic algal blooms, massive fish kills and the collapse of fisheries are symptoms of fundamental changes in ocean life that are caused, in part, by overfishing.

In heavily exploited waters, the fish simply cannot repopulate fast enough to keep up with the harvest. Marine parks would give them a chance, the scientists said.

Today, less than 1 percent of the world’s waters are protected in marine reserves. But the study showed that even these limited areas have had a dramatic effect on the recovery of sea life recovery.

The study was produced by the National Center for Ecological Analysis and Synthesis and endorsed by 150 of the world’s top marine scientists.

President Clinton in May signed an executive order calling for a national system of marine protected areas, but the proposal met with criticism from lawmakers and the fishing industry. They contended there was little scientific evidence showing the value of marine sanctuaries, Lubchenco said.

The new study, she said, now provides that evidence.

The study of 89 marine reserves around the world showed that, given the chance, fish and other marine life quickly restore themselves where they are protected. The marine species then fan out, reseeding adjacent waters.

“We now have strong evidence that reserves work,” said Robert Warner, a professor at the University of California, Santa Barbara. Within and around marine parks, he said, fish population doubles, fish size grows by 30 percent and reproduction triples.

“It all happens within two to four years and it lasts for decades,” he said.

Palumbi said that unlike terrestrial parks, the benefits of a marine sanctuary spread far behind their boundaries.

“Most marines species start as tiny eggs or larvae that drift and may mature miles away from their parents,” Palumbi said. Some drift up to 60 miles in each generation, starting new populations in increasingly distant waters.

In places where marine reserves have been tried, said Callum Roberts of the University of York in England, fish populations have exploded within the reserves and quickly enriched the surrounding ocean. The result has been a revival of commercial fishing in some areas where fish were once scarce.

When snapper and lobster populations in coastal waters of New Zealand crashed, the fishing industry there went into a depression.

Roberts said that after a series of marine reserves was created in the 1970s, the snapper population in a few years was 40 times higher inside the reserves and lobsters were increasing at the rate of 5 percent to 11 percent a year. Outside the reserves, the fishing industry now thrives.

“Fishers in New Zealand now ring the reserves with their traps,” Roberts.

In reserves around the Caribbean island of St. Lucia, fish populations tripled in three years and doubled in the surrounding waters, benefiting commercial fisheries.

When the scallop population crashed in the Georges Bank, a fishing area in the North Atlantic, a 6,500 square mile area was closed to fishing. Roberts said that in five years, the scallop population inside the reserve was 14 times greater than in unprotected waters. Fishing boats now concentrate on the borders of the reserve, he said.

“There are still some people who believe we can continue with business as usual,” Roberts said. But he said some fisheries are now at a “crisis” stage and some species may not recover without marine reserves.

“We are running out of time,” he said.