Group to Study Vessels’ Effect on Gray Whales

The prospect of as many as 45 U.S. Navy hovercraft cruising the waters off San Diego County and a flotilla of yachting buffs mustering here for the America’s Cup races has raised new questions about the impact of boat traffic on migrating gray whales.

Researchers hired by the Navy intend this winter to study the effects of the Navy’s new “landing craft air cushion,” a massive, high-speed craft being used increasingly in exercises along the coast from Camp Pendleton to the Mexican border.

And a national organization that seeks to protect whales voted this month to oppose any plan to hold Cup races from January through April--the period during which the Cup trials, if held, would occur off San Diego in 1991.

Unusual Opportunties for Study

Scientists say little is known about the long-term impact of boating on the migration of gray whales, an estimated 15,000 to 20,000 of which travel south from Alaskan waters each year to their breeding lagoons off Baja California.

Some say the species appears adaptable and resilient, based on its recent comeback from near-extinction. But they say the new pressures in San Diego County have created unusual opportunities to learn more about the whales’ remarkable, 15,000-mile round trip.

“It’s a magnificent phenomenon that’s been going on for thousands of years,” said Seth Schulberg, president of the environmental consulting firm doing the Navy’s study. “It would be sort of disappointing if in 20 years we could manage to totally disrupt it.”

“It’s possible for the (activities) to exist side by side without detriment to the whales,” said Stephen Leatherwood of Sea World Research Institute, which is at Hubbs Marine Research Center, the research arm of the well-known marine park. “ . . . But we would do well to make this a test case of how sensitive we are in Southern California about our ‘pet whales.’ ”

Landing Craft’s Impact on Whales

The Navy’s interest in the whales stems from its decision to base at Camp Pendleton as many as 45 landing craft air cushions, or LCACs--each 87 feet long and 47 feet wide, capable of carrying upward of 60 tons and traveling at speeds above 40 knots, or 46 miles per hour.

The hovercraft, which travels above land and water on a cushion of air, is described by Navy officials as “the newest concept in amphibious warfare,” designed for speedily shuttling Marines and equipment from 30 miles out at sea onto enemy shores.

Three are already operating out of Camp Pendleton, selected as one of only two such bases in the United States and the only one in the West. Navy officials say three more of the craft are to arrive shortly; the full complement is expected by the mid-1990s.

But in applying in the early 1980s for permits to operate the craft, the Navy encountered the federal Endangered Species Act, under which any federal agency contemplating activities that might harm an endangered species must consult with federal wildlife agencies.

“Our major concern is adding more and more noise to the environment and greater and greater disturbance to the gray whales as they migrate down the California coastline,” Jim Lecky, a wildlife biologist with the National Marine Fisheries Service, said last week.

“We know that most animal populations withstand disturbance up to a point and then they start to abandon their habitat,” he said. “ . . . So we’re concerned about where that threshold of disturbance might be that would cause them to abandon their migratory route.”

So Lecky’s agency made it a condition of the Navy’s permit that the Navy study the effects of the hovercraft on the whales. If it is found that the whales are altering their route, the service might require that the Navy limit its activities to non-migratory seasons, Lecky said.

The study began informally two years ago. Members of Schulberg’s Cardiff-based firm, Southwest Research Associates, sallied forth out of Oceanside in an inflatable boat and on whale-watching vessels for tourists to begin delineating the migratory routes without the presence of hovercraft.

Last year, the study picked up. Between January and April, the consultants flew 50 hours of aerial surveys in Marine Corps helicopters out of Camp Pendleton, making detailed observations of the whales’ movements and behavior.

Group size, respiration rate and direction of swimming were noted, as well as the presence of pairs of whale cows and their calves. The surveyors moved methodically back and forth along straight lines between the coast and Santa Catalina and San Clemente islands.

According to Schulberg, one of the most striking findings of the first two years was how far offshore the southbound whales were traveling, mostly sweeping west of the islands before cutting east to hug the coastline south of the border.

“A lot of people have speculated that the reason you’re seeing more whales offshore is a direct influence of traffic,” Schulberg said “That’s a topic to be studied. I don’t think anyone knows the answer.”

Study to Be Broadened

This year, the study is to be expanded to include what Schulberg called “LCAC-gray whale interactions.” The consultants intend to spend 130 hours in the air, much of it during the peak migration and when the craft will be engaged in daily exercises.

Next year, the final year of the study, the consultants and the Navy intend to encourage closer contact between the hovercraft and the whales, directing the hovercraft operators from the air to areas where whales are traveling.

“We will determine what is the zone of influence an LCAC has to a whale,” said Steven Kovach, a fish and wildlife specialist with the Navy. “How close does the machine have to get before the whales react to its presence? The whales may flat ignore these things, we don’t know.”

However, Schulberg noted that the surveyors will studiously avoid arranging encounters between the hovercraft and so-called “cow-calf pairs.” Such pairs are “too sensitive a population segment to risk experimentation,” Schulberg said.

Finally, the study will produce a report for the Navy detailing where the whales travel and the chances of a hovercraft encountering one, as well as procedures for hovercraft operators when they spot a whale and seek to avoid contact.

“The LCAC operator is just as concerned about running into a whale as the environmentalists are concerned,” Kovach said. “If you’re scooting along at 40 knots and you run into a solid, stationary object that weighs a couple of tons, it’s going to do some damage.”

Opposed to Yacht Races

A related concern about increasing boat traffic has been raised by another group.

The American Cetacean Society, a national group that supports conservation and protection of marine mammals, voted one week ago at its national board meeting to support a policy barring America’s Cup races in San Diego during whale migration.

Tom Lewis, vice president of the organization and a marine biologist with the Los Angeles County Museum of Natural History, said the group’s concern is focused less on the racing yachts than on the flotilla of observers expected to turn out for the months of trials and races.

“They could force the animals farther offshore than they prefer to be,” Lewis said. “It could add stress into the situation of a newborn animal. But a lot of this is undocumented, because there has been little work done about animals’ reactions to boats.”

However, the society’s concern may turn out to be moot. Last Wednesday, a New York court upheld a claim by New Zealand that, under the America’s Cup’s original Deed of Gift, New Zealand should be permitted to mount a challenge for the Cup in 1988.

The San Diego Yacht Club, current holder of the Cup, has not announced how it will respond to the decision. But the ruling could mean that few if any other challengers can enter the race on such a short timetable, reducing the number of observers who attend.

According to Leatherwood, the senior staff scientist for Hubbs Marine Research Center at Sea World, questions about the impact of boat traffic on whales have arisen regularly over the last 15 years as recreational boating, commercial shipping and military uses have increased off Southern California.

But he said it is difficult to determine the effects of a single activity on whale migration patterns, and he cautioned against too quickly attributing variations in behavior to human activities rather than subtle environmental changes.

He noted that the use of acoustic waves by oil and geological survey teams initially prompted fears that migration routes would be disrupted. Other concerns have involved the impact of pollution and fishing gear, such as gill nets that kill about 20 whales a year.

Leatherwood cited several studies of whales’ responses to interference.

In the early 1980s, scientists at Hubbs studying whales’ responses to natural oil seepage off Santa Barbara found that the whales made longer dives, spent less time on the surface and swam faster. But Leatherwood said there was no evidence that the experience was “detrimental.”

A comparable study off Monterey measured whales’ responses to sounds projected at them through the water. Though the whales avoided intense sounds within hearing range, Leatherwood said the study was unable to prove a long-term effect.

Finally, Leatherwood mentioned the observed response of gray whales to the siting of a scallop fishery in San Ignacio Lagoon in Baja California: Whales used the lagoon extensively before the fishery opened, seemed to avoid it when the fishery came, and returned after it closed.

“Circumstantial evidence or hard science?” Leatherwood asked. “I don’t know.”

“I think there are thresholds of interference beyond which animals simply will not tolerate that environment any further,” he added. “ . . . But how far that goes, neither I nor anyone can say.

“My working hypothesis would be that if you were willing to study it for long enough, you could find a threshold of noise, pollution and other interference that would either run gray whales out of an immediate area or would stress them so much that it incapacitated them.”

That kind of stress could interfere with a female whale’s ovulation or cause the whale to abort a fetus, Leatherwood said. Or, in the case of noise interference, it could interrupt the whales’ ability to communicate.

But Leatherwood said he believes that gray whales appear to be “highly adaptable” and that it would take a significant interference to affect their survival. He said he is more concerned about fishing nets, “because animals are dying in gill nets along the California coast each year.”

Roger Payne, senior scientist at the World Wildlife Fund in Washington, D.C., and president of a Massachusetts-based institute that does long-term studies on long-lived animals, said he too believes experience indicates that gray whales may be relatively resilient.

“The brutal fact is that during a period of unprecedented growth and increase in ship traffic, the populations of whales have recovered to what may be their original numbers,” Payne said in a telephone interview last week.

“That suggests to me that, however annoying the various annoyances . . . may be, that is not seriously affecting their reproductive fitness,” Payne added. “ . . . If it’s not affecting the number of young, then it’s hard to argue that it’s destroying the population.”

Payne then went a step further.

Citing what is called the “friendly whale phenomenon,” he noted that gray whales on occasion actually pursue human contact, approaching tourist boats and even rolling over to display their bellies, which some boat captains obligingly scratch with brooms.

“What this suggests is that maybe whales even like people,” Payne speculated. “If they do, and if one presses legislation to remove that contact, my feeling is that could be a mistake. It could prevent or slow what I think is potentially the most interesting bond between humans and mammals that I have seen.”