Scientists Alarmed by Whale Deaths

by Mark Bourrie

The carcasses of more than 100 of the whales, which can grow to 15 meters and weigh 16 tonnes, have been found on the beaches of Washington state, Alaska and British Columbia. Hundreds more are believed to be drifting at sea.

Fisheries officials in British Columbia, who spent three months testing tissue samples for chemicals and dissecting the carcasses, announced last week that the whales simply may have starved to death.

The scientists said the whales apparently lacked sufficient intake of food to produce the necessary blubber to sustain them on their long migration from Baja California to the Bering Sea.

The question now is how could this happen? Canada's environment minister, David Anderson, has asked researchers here and in the United States to try to determine why the whales have not been getting enough food.

"It's natural, as far as we can tell, but it's something that we must research...The Americans have more whales washing up on their beaches than we have, so they are very involved in this, and will be doing the research in the Bering Sea," Anderson said.

The research will be conducted by the Oceans and Atmospheric Administration and the Fisheries Service of the United States government, he said.

The Canadian scientists who examined the whales that died on the British Columbia coast have been surprised at the malnourished condition of the mammals.

"They had very low fat reserves," said Peter Ross, the Canadian Department of Fisheries scientist who supervised the study of the whale kill. "Their blubber thickness was very thin and they essentially looked like they had starved to death."

A second, very small, population of whales migrate down the coast of Asia to breed off South Korea. The whales in this group were hunted until 1969. A third population of gray whales, in the north Atlantic, was killed off by whalers 300 years ago.

Environmental scientists are concerned that the whales may have been contaminated with toxic chemicals such as polychlorinated biphenals (PCBs), which have been found in large amounts in the meat of killer whales along the coast of British Columbia.

"In the summertime, these gray whales are essentially bulking up such that they will be able to swim down to Mexico," said Ross.

"Then they reproduce, then migrate backwards up to the feeding grounds.

"It really just looks like they just ran out of steam, or a number of them did, on their return trip."

Ross believes the gray whales, which are filter food through baleen plates in their mouths, were victims of a drop in food production in the Bering Sea.

Scientists here say that recent El Nino and La Nina currents have caused problems with the ecosystem of the northern Pacific Ocean.

Fishermen on the Canadian coast have reported seeing species of fish that are normally found no farther north than California, while cold-water salmon stocks have dropped dramatically.

Gray whales no longer are an endangered species, although they were hunted to the edge of extinction at the turn of the century.

There are about 25,000 off the west coast of North America. Prior to the arrival of commercial whaling, they were hunted by Pacific Coast indigenous communities and, last spring, a Washington state native band again resumed a ceremonial hunt that aroused controversy among environmentalists.

Ross said that although 100 whales washed ashore, the Canadian researchers believe about 1,000 whales died during the summer migration.

The rest of the whales are now beginning their migration southward, and Canadian fisheries officials were monitoring them to see if this year's summer feeding was more successful for the whales.

Another indication of low food supplies was the lack of calves spotted during the whales' northward migration, he said.

"We observed very few calves returning with the females northwards," said Ross. "We suspect this is another indication that during their feeding up in the Bering Sea, the females didn't get enough nutrients to support their reproductive cycle."

Reports from Mexico indicate grey whales have had problems in their traditional breeding grounds because of coastal salt mining which has affected the chemical composition of the ocean.

Ross said the buildup of toxins did not appear to be a factor in the latest whale deaths, however. "We found actually fairly low levels of pesticides and PCBs," Ross said.

"It's good news from a contaminant point of view," he said, "but obviously, these gray whales are telling us something very important about the state of our oceans.

"We've seen other things happening in the Pacific Northwest that concern us as humans, such as declining salmon returns and other problems. We're not sure whether some of the oceanographic changes that we've observed in the North Pacific and the Bering Sea is a natural cycle...or whether climate change, as a result of human activities, might be exacerbating the situation."