The beluga whales make a shrill sound as they stick their noses out of the water, watched by conservationist Michel Moisan. They are a rare sight this far south — and the chemicals washing into their river are keeping them that way.
Most beluga are found in the Arctic, but a rare pocket survives — just — here where the river Saguenay river meets the Saint Lawrence some 500 kilometers (300 miles) east of Montreal. They are the only ones among the 13 whale species in the river to live here all year round.
Spying a group of beluga through binoculars, Moisan, of the local Marine Mammal Research and Education Group, draws close in his boat, photographs them, notes their location, then fires a dart to grab a sample of fat from the creatures to glean more information on their health.
“It’s a population in peril,” says Veronik de la Cheneliere, a biologist with the conservation group. “The main reason for its decline used to be over-hunting, but that ended in 1979.”
As well as banning the hunt, the government in the 1980s restricted the use of chemicals such as the toxic pesticide DDT and the industrial chemical PCB, which were found in beluga carcasses washed up on the Saint Lawrence’s banks.
These measures were supposed to allow the beluga population to grow by three percent a year. But 25 years on, the numbers in the river have not changed, staying at between 1,000 and 1,200, says Veronique Lesage, a researcher at the Canadian fisheries ministry.
Meanwhile, other chemical threats have flowed in.
“The beluga is currently accumulating the biggest load of persistent contaminants,” chemicals that do not break down quickly, said Michel Lebeuf, a specialist from the Maurice-Lamontagne research institute.
His team analysed the carcasses of beluga over 15 years and estimates that the traces in the fat of the whale of chemicals banned in the 1980s have fallen little — in fact, they remain “still very significant.”
This is partly explained by new knowledge about the mammals’ ages: belugas live up to 70 years, twice as long as previously thought, according to a recent report in the Canadian Zoology Review.
So belugas swimming around the Saint Lawrence today could have been alive in the 1970s, when dangerous chemicals were pumped intensively into the water.
“To these products are now added other persistent compounds, more and more commonly used,” such as chemicals used in plastics and solvents, said Lebeuf.
The poisonous cocktail is passing into the whales and via their placentas to their unborn young. The rate of cancer among male beluga in the Saint Lawrence river is at 25 percent.
“Previously, young belugas were arriving in a contaminated environment, but there wasn’t this legacy from the mother,” Lebeuf said.
“Today, beluga that reproduce transmit major contamination, in addition to being in an environment contaminated by new compounds.”
The species’ protected status in Canada forbids anyone from coming within 400 meters (yards) of them, but this is often ignored by visitors in boats who sail close for a view.
“You see lots of people getting too close,” says Jean Desaulniers, a local marine conservation official.
“There is no sign of recovery of this species in the Saint Lawrence,” said de la Cheneliere. At the beginning of the 20th century, there were an estimated 14,500 beluga whales here.