Environment

By Jamie Murphy.

A DEADLY ROUNDUP AT SEA Pressure mounts to save the dolphin by restricting tuna fishing AND WITHIN MINUTES HALF A DOZEN POWERFUL SPEEDBOATS ARE LOWERED OVER THE SIDE INTO THE BRIGHT WATERS OF THE EASTERN PACIFIC. BURSTING INTO NOISY LIFE, THEY SLICE THROUGH THE CRESTING WAVE TOPS AT 35 KNOTS. DEAD AHEAD OF THEM, A POD OF PORPOISES, OR DOLPHINS, BOLT WITH FRIGHT, BUT THE FLEEING MARINE MAMMALS ARE SOON OVERTAKEN. LIKE COW PONIES ROUNDING UP CATTLE, THE SPEEDBOATS HERD HUNDREDS

OF DOLPHINS INTO A CIRCLE, WHILE THE 250-FT. MOTHER SHIP SLOWLY surrounds the spray-filled confusion of boats and dolphins with a mile-long, 450-ft.-deep nylon net.

Why pursue and trap these sociable, intelligent cetaceans? The dolphins are merely a fisherman's convenience. A few feet beneath them swims the real object of the hunt: a huge school of yellowfin tuna, which for reasons that baffle scientists often congregate below pods of dolphins. More than 90% of the yellowfin caught by the U.S. tuna fleet last year were taken by "setting on porpoise," the practice of dropping nets where dolphins frolic on the surface. As a result, thousands of dolphins are swept into tuna nets each year. Many of them become entangled beneath the surface and, since they are air breathers, drown.

Now, in an effort to curb the mounting toll on dolphins, the environmental group Greenpeace has threatened legal action. It hopes to make the National Marine Fisheries Service (NMFS) enforce existing regulations limiting the number of dolphins that can be killed by tuna fishermen. That would be the most drastic action yet in a continuing campaign by conservationists to save the dolphin. If Greenpeace succeeds in its effort, the San Diego-based American Tunaboat Association estimates, the fleet will lose as much as $35 million in revenue.

Conservationists have been lobbying for measures to protect the animals since the early 1970s, when they distributed bumper stickers reading WOULD YOU KILL FLIPPER FOR A TUNA SANDWICH? In 1972, when 304,000 dolphins were lost to the nets, Congress passed the Marine Mammal Protection Act, which specified that dolphin kills by commercial fishermen were to be reduced in theory to "insignificant levels approaching a zero mortality." Further legislation, passed in 1984, fixed a numerical limit on the dolphins that could be killed by the U.S. tuna fleet: 20,500 dolphins a year.

The NMFS acknowledges that the fleet this year is already approaching its limit. "If the killing continues at the present rate," says Charles Fullerton, director of the agency's Southwest region, "the fleet will reach that (number) in September." Pressured by the environmentalists on one side and the tuna fishers on the other, the agency is still debating its next step.

Environmental groups insist that the kill rate is higher than even the Fisheries Service's estimate. For their part, the tuna fishermen dispute both Greenpeace's and the NMFS's kill estimates, claiming that Fisheries Service observers, who are assigned to only some of the 29 boats in the fleet, have incorrectly extrapolated their data. The fishermen are also irked by the fact that the foreign tuna fleet, which has no legal quota, will most certainly ignore any forthcoming NMFS restrictions. These ships, say the fishermen, may have already killed more than 20,000 dolphins in 1986. On only one point is there agreement: observers must be placed on all U.S. tuna ships as soon as possible to establish a true count.

The squabble comes at a time when the U.S. tuna fleet has made substantial progress in reducing dolphin deaths. Tuna fishermen say that between 98% and 99% of the animals captured in nets are released unharmed, and the tuna-boat association has instituted the "Golden Porpoise Award" for the skipper with the fewest dolphin kills in a season.

The most effective way of freeing trapped dolphins from a net that is full and cinched shut at the bottom is for the ship laying the net to run in reverse, dragging the net and its finny contents into an elongated shape (see diagram). Crewmen in rubber rafts then drive the surface-swimming dolphins toward one end, and as the ship pulls the net, the dolphins spill out, leaving the tuna behind. Despite these efforts, an average of eight dolphins die during each netting, often at night, when freeing them is more difficult.

Dolphins, which are among the more intelligent mammals, seem to have recognized the tuna-fishing threat. As recently as 15 years ago, says Veteran Tuna Skipper Harold Medina, they could be rounded up easily with a couple of skiffs propelled by small outboards. Sometimes they would even play in the mother ship's bow wave. Now, in areas where dolphins have been heavily fished, they are much more difficult to corral, forcing the fishermen to resort to more and higher-powered chase boats. Mexican fishermen call these recently sophisticated dolphins the "untouchables," because they disappear at the first sight of a fishing boat. The discerning mammals are apparently able to tell the difference between fishing vessels and other craft, because they still approach small sailboats or motor cruisers. Still, marine biologists complain that it is increasingly difficult to study dolphins and take population counts. The oceanographic vessels evidently look too much like tuna boats.

With reporting by Jonathan Beaty/Los Angeles