This first official sign of interest in the belugas' fate was followed by some startling discoveries in the early 1980s, by scientists Daniel Martineau and Pierre Beland. The beluga population was showing signs of being even more seriously affected by human activities than had previously been thought. In particular, the scientists found that the whales were suffering from a variety of unexpected dieseases.
Autopsies conducted on whales washed ashore along the banks of the St Lawrence revealed an extraordinary array of disorders. One young beluga, aged two and a half years, had a perforated gastric ulcer with peritonitis, broncho-pneumonia, dermatitis associated with a herpes-like virus, and chronic hepatitis.
Some of the reported disorders had never been recorded in toothed whales before, including bladder cancer, rupture of the pulmonary artery, and skin fibrosis.
Many of the whales were found to have been polluted by a mixture of some two dozen contaminants including polychlorinated biphenyls (PCBs) and the pesticides Mirex and DDT. PCBs in their blubber were recorded at levels as high as 576 parts per million (ppm). (Many countries consider fish too contaminated for human consumption if they contain levels of just 2 ppm.) The milk of some nursing females was found to be contaminated with PCB levels up to 3,400 times higher than is considered safe in drinking water.
The instance of bladder cancer was considered particularly interesting because, in the late 1970s, it had been discovered that in the region directly adjacent to the territory in which the belugas lived, there were 60 percent more cases of bladder cancer in human residents than was statistically likely.
A study of workers at the Alcan aluminum smelter (the region's largest employer) outside the town of Jonquiere, situated bewteen the Saguenay river and Lac St-Jean, revealed 73 cases of bladder cancer. The number of cases reported had risen to more than 130 by early 1990.
Most of these occurred in employees working on the 'potlines' were alumina powder is cooked into ingots. The study noted that such workers, who were exposed to extremely high levels of a group of chemicals known as polycyclic aromatic hydrocarbons (PAHs), were five times more likely to develop bladder cancer or tumours than other workers at the plant.
The high incidence of bladder cancer is not the only major health problem in the region. According to a federal government health study, the area also has the highest rate of birth defects in Canada. A study by the Quebec Department of Health found that the Saguenay/Lac St-Jean region had the province's highest rate of deaths as a result of malignant tumours, cardiovascular and cerebrovascular dieseases, and the second highest rate of stomach, lung and respiratory tumours.
In the search for a link between the precense of PAHs and the belugas' problems, brain tissue from three of the autopsied whales were sent to biochemist Lee R. Shugart at the Oak Ridge National Laboratory in Tennessee for analysis. The tissue was indeed found to have metabolized quantities of the carcinogenic PAH compound benzo-a-pyrene in concentrations that, according to Shugart, 'would produce cancer in other laboratory animals under similar conditions.'
The revelations about the health of the St Lawrence beluga population generated a great deal of media interest which significantly increased the public's awareness of the belugas' plight, but the action necessary to save these creatures and ensure their future survival has still not been forthcoming. Both national and provincial governments, while engaging in a great deal of rhetoric, and some research, have refused to take action until there is scientific proof of the specific cause of the belugas' decline.
In this respect, the story of the St Lawrence beluga is representative of the problems faced by all who are concerned about the future of small cetacean populations. By the time scientific proof is available, if indeed such proof is possible, it may be too late.
For the St Lawrence beluga, this may already be the case. Recent autopsies have continued to uncover new disorders: cancer of the liver, abdomen and mammary gland; a hermaphroditic beluga, (with both male and female genital organs); and a type of bronchial pneumonia associated with profound immunosuppression, similar to that found in human AIDS sufferers.
The latest evidence suggests that the birth rate of these belugas is not keeping pace with the mortality rate. Furthermore, as already noted, beluga calves are ingesting high doses of contaminants through their mother's milk. Even more disturbing is the discovery that carcinogenic PAHs have become attached to the belugas' DNA and have altered its genetic structure. The damage is thus passed on from generation to generation.
In the words of Dr Joseph Cummins, a geneticist at the University of Western Ontario, the St Lawrence belugas are, 'to all intents and purposes, absolutely doomed. I don't see how they can possibly survive, bearing the gene damage they do.'
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