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Environment : Fewer Whales Point to Big Problem on St. Lawrence : Toxic chemicals from the Great Lakes are impairing the mammals' ability to reproduce.

October 25, 1994|CRAIG TURNER | TIMES STAFF WRITER

TADOUSSAC, Canada — The young, one-ton beluga whale broke away from its herd and glided astern of the research boat, basking in the bubbles of the prop wash. Daniel Lefebvre, braced on the observation deck atop the cabin, lowered his clipboard for a moment and laughed.

"Look, beluga Jacuzzi!" he called out to the others on the boat.

It was just the kind of playful, spontaneous, seemingly affectionate behavior that endears the sleek, ivory belugas to researchers and whale watchers alike here, where the St. Lawrence River meets the Saguenay River and widens toward the Atlantic Ocean.

But these belugas are in trouble. They are permeated with toxic chemicals washed down from the Great Lakes. The chemicals appear to have impaired the whales' ability to reproduce.

Large-scale hunting of St. Lawrence belugas ended in the 1950s, and there are no other known predators of the river whales. But in all the years since, the population has failed to increase, stabilizing at 500 to 700. A small cadre of marine researchers, led by biologists Pierre Beland and Robert Michaud, is trying to pin down the cause.

So far, the most likely explanation is the toxin levels in the whales. In autopsies of nearly 70 beluga carcasses taken from the St. Lawrence in the last 12 years, Beland has recorded elevated levels of mercury, lead, selenium, PCBs, DDT and other chemicals. Lead concentrations in St. Lawrence belugas, for example, are about 10 times higher than those found in belugas that live in the Arctic. Beland has found as many as 700 parts per million of PCBs in St. Lawrence whales, compared to 5 parts per million in Arctic belugas.

Beland and Michaud believe that the chemicals have damaged the belugas' immune system, slowed reproductive rates and increased infant mortality. But they cannot yet prove this.

"Ask your average person and they'll say, 'Yes, if you put toxic chemicals in a whale, it will have an adverse effect on its health,' " Beland said. "But science doesn't operate that way, government doesn't operate that way. They need proof."

So the research team, financed on a shoestring and based in this Quebec hamlet, has embarked on a two-stage approach. Beland, assisted by Sylvain DeGuise and the University of Quebec at Montreal veterinary school, continues to perform autopsies on St. Lawrence belugas and compare his findings to what is known of healthy belugas in the Arctic.

Michaud and the staff of whale researchers in Tadoussac are chronicling beluga behavior and social patterns, trying to find out how all the toxins got into the belugas and exploring other potential causes for the stable population.

That takes Michaud, Lefebvre and their volunteer assistants out on the river daily, weather permitting, from May to October.

The Tadoussac area is a rich laboratory for whale research, rivaled by few other places in the world.

The colliding flows of the St. Lawrence and Saguenay rivers--which contain salt water close to the ocean--and the end of an underwater canyon reaching in from the Atlantic combine to make this a profitable feeding ground for seagoing mammals. Blue, fin, humpback and minke whales are regularly spotted, along with the beluga; a sperm whale will occasionally appear.

Whale-watching and tourism are principal summer industries, and the whale watch boats mainly cooperate with the scientists. This year, for example, they agreed to stay away from belugas so they would not influence the whales' behavior and interrupt the research.

Belugas are among the smallest whales, reaching lengths up to 16 feet and weights of a ton or more. They are pale gray in youth but turn a bright white as they mature. Their life span is about 30 years.

Most belugas live in Arctic regions, where they are subject to subsistence hunting by natives and to predatory polar bears and orcas.

Despite such pressures, the Arctic population--perhaps 100,000 in Canadian, Alaskan, Russian and Greenland waters--is considered stronger than the St. Lawrence colony, declared endangered in 1983. Only recently, scientists determined that the St. Lawrence belugas live year-round in the Tadoussac area and do not migrate out to the Atlantic in winter.

Scientists associated with Michaud are doing research on blue and fin whales, as well, seeking to track their migrations and social structures. But the most promising research is on the belugas.

The team has not yet figured out the main source of the toxins, in part because the belugas have a wide and varied diet. The latest theory is that eels carrying high toxin levels pass on the chemicals when they are eaten by the belugas.

"The interesting thing about belugas is they present an enlarged picture of what's happening with other species," Michaud said over a beer at a waterfront tavern after a day on the research boat.

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