Dolphin Count Under Way Over Tuna Fishing Dispute

For the past month, Rennie Holt and a team of scientific observers have been crisscrossing the eastern Pacific Ocean, counting dolphins. They will be at it for another three months.

Over the next five years, they will retrace the same route in hopes of establishing, beyond dispute, whether the mammals’ numbers have decreased as a result of the netting technique used by tuna fishermen.

The finding by these scientists from the federal Southwest Fisheries Center in La Jolla are to be used by Congress to determine whether to adjust present annual limits on dolphin kills by American tuna fishermen.

The accuracy of data used to set the quotas have been a source of controversy among environmentalists, government scientists and fishermen since they were first posted in 1972. The quotas resulted from environmentalists’ outcry and subsequent congressional action to try to protect what appeared to be the dolphins’ dwindling numbers.

Data Based on Old Surveys

“They (the numbers) right now aren’t really very believable,” said Holt, chief scientist for the five-year counting survey. Present data is based on old surveys and information from fishermen going back to the 1960s and earlier.

Fishermen frequently locate tuna schools by spotting dolphins, which often swim above the tuna. When nets are spread around the dolphins to capture the tuna, some of the mammals become entangled and die.

In June, officials of the Southwest Fisheries Center warned fishermen that they would exceed the 1986 annual quota of 20,500 dolphin kills as early as late August if they are not more careful in their methods.

In an attempt to end the bickering over numbers, the scientists plan to spend 12-hour days using computer-enhanced spotting systems and a statistical theory designed by the U.S. Navy for deep-sea tracking to locate schools of dolphins and estimate the numbers within each school.

Representative Area

“It’s a 6-million-square-mile area from Baja (California) south to Peru and west almost to Hawaii,” Holt said. “We’re going to try and cover a representative area in a systematic manner.”

The survey involves two ships from the National Oceanic and Atmospheric Administration, the parent agency of the fisheries center. The two vessels will spend 30 days at a stretch at sea.

The researchers hope that statistical analysis together with the new spotting methods will allow a far more accurate count.