Scientists Warn of Need for Fishing Curbs to Protect Sharks

The king of the ocean predators is falling victim to land’s deadliest hunters, people, and may face doom unless governments around the world agree to sharply limit shark catches.

The shark-fishing industry boomed in the 1980s to feed the world’s growing appetite for shark meat, inexpensive and popular with yuppies, and for delicacies such as shark-fin soup.

Now the dusky shark, once common off the Northeast coast, has all but vanished. The night shark, a formerly reliable catch in the Florida Straits, is rarely spotted. A lemon shark research project in the Keys was abandoned last year when researchers could not find enough animals.

And sport fishermen report that the number of the sought-after mako sharks caught in the Atlantic is dropping sharply.

“I think we are reaching a critical stage, if we are not already there,” said Eric Hawk, administrator for the National Marine Fisheries Service in St. Petersburg. “There is a strong feeling that the reason we have not yet detected a collapse is that there are many species out there, and it’s hard to tell if some are in trouble.”

The U.S. Commerce Department is ironing out the final wrinkles in a plan that would limit to 5,800 metric tons--roughly half a million animals--the commercial shark catch in federally regulated waters in the Gulf of Mexico, the eastern Atlantic and the Caribbean. Estimates are that three times that amount of shark will be either thrown away by boats seeking other fish, such as tuna, or caught by sport fishermen.

Hawk noted that those limits would not apply to state waters--where 65% of sport catches occur--or to countries such as Mexico, which may take double the U.S. catch.

The fragility of the shark population and the shark’s vital role in shaping ocean evolution is only now beginning to be understood, said Samuel Gruber, a University of Miami researcher who has spent a lifetime studying the ancient animals.

“They are more like a whale than a fish--they have their young one at a time,” Gruber said. “But the sharks play a much more important role than the whales, because they maintain the ecological health and balance of the seas.”

Just as wolves and mountain lions once culled antelope herds in the American West, sharks have been guiding the evolution of fish for 400 million years, he said.

Anecdotal evidence from other biologists and sport fishermen indicates that the disappearance of sharks has accelerated over the last decade, coinciding with the boom in commercial shark fishing.

“My impression is that the chickens have come home to roost. This fishing has been going on for about 15 years, and that’s how long it takes for sharks to mature,” Gruber said.

The growing shark-fishing industry is suspicious of the biologists’ data and the Marine Fisheries plan projected to take effect in June. They have hired an attorney and expect to sue the program.

Jim Bonnell, vice president of the Southern Offshore Fishing Assn. and a shark fisherman, said reports from commercial fishing fleets fail to support the theory that shark populations are in trouble.

“In the years we have been doing this, we haven’t seen any decrease in the number of fish, or the size of the fish,” he said.

The 800-member association estimates that there are 45 full-time shark boats in the Tampa Bay area alone, and far more than the 150 estimated by the government in the area covered by the plan. Many fishermen have already been hit hard by new reef-fish restrictions, and have switched to shark to make ends meet.

Government biologists do not deny that their data is sketchy. But they insist that it points to danger for sharks.

A 1980 study estimated that maximum sustainable yield for the region was 25,000 metric tons. Yet industry reports show that in the last decade up to 52,000 tons a year was fished annually, with most of it thrown away by boats that caught sharks by accident as they looked for other fish. The figure for 1988, the latest year available, was more than 43,000 tons.

“There’s too many fishermen and we’re too efficient,” said Jack Casey, a Marine Fisheries biologist in Narragansett, R.I.

Sharks have been in vogue before, he said, with sometimes disastrous results. In 1938, several states developed shark fishing to meet a demand for the animals’ liver, which is high in vitamin A. Most of the fisheries collapsed within 10 years, in part because of over-exploitation.