Geoscience Reference
In-Depth Information
er waters; in the case of the St. Lawrence population, the birthing territory is the Saguenay estuary. The fresh-
water environment also stimulates accelerated growth of the epidermis, or molting.
Although belugas are a circumpolar species, found in all the northern seas, they have been in the St.
Lawrence environment for a very long time, as demonstrated by the discovery of bones in marine deposits of
the ancient Champlain Sea dated to 10,500 years ago. The whales were hunted by the indigenous Montagnais
Indians, but large-scale exploitation began with European settlement. Brush weirs, first erected at Kamouraska
at the beginning of the 18th century, proved deadly. Five hundred belugas were captured on a single tide at
Rivière-Ouelle in 1880, and eighteen hundred in one season at this same site. At the time, the population was
estimated at five thousand animals. As late as the 1930s, a bounty was placed on belugas (which were erro-
neously thought to be depleting commercial fish stocks such as cod and salmon), leading to the death of nearly
two thousand whales. Although intensive hunting was banned in the 1950s, the population was officially pro-
tected only in 1979; by then, however, it had been reduced to five hundred animals, probably one-tenth of his-
torical levels. Current estimates place the population at a thousand animals.
The slow recovery of the species has been attributed to several factors. Their range has contracted in recent
decades because of the loss of critical habitat. Hydroelectric development on the Bersimis, Manicouagan, and
Outardes Rivers has altered the temperatures and biological productivity in their estuaries, which once fur-
nished one-third to one-half of the species' summer habitat.
Today, belugas are largely confined to the confluence of the Saguenay and St. Lawrence, where local up-
welling creates ice-free waters in winter and near Arctic conditions in summer conducive to belugas. Some be-
lugas disperse as far as the limits of the estuary environment at the mouth of the St. Lawrence.
Formerly, they also congregated along the coast of the Gaspé in spring and the lower North Shore of the
Gulf in summer, but they now appear at these sites only sporadically.
Chemical contamination may be another factor limiting population growth. The St. Lawrence beluga habitat
is downstream of the highly populated and industrialized Great Lakes watershed. Autopsies of stranded indi-
viduals have detected a veritable cocktail of contaminants, including high levels of fifteen toxic chemicals and
nine heavy metals—in some cases, twenty-five to one hundred times the levels found in Arctic populations.
Among the pollutants that have been found are pcbs and pahs, ddt and other pesticides, and the heavy metals
cadmium, mercury, cobalt, and lead. The source of these contaminants seems to be the whales' prey, including
the American eel, which migrates downstream from the industrialized regions of the Great Lakes and the up-
per St. Lawrence on its way to breeding grounds in the Sargasso Sea. The stranded whales also had unusually
large numbers and types of lesions, ulcers, and tumours, which, if they did not cause death, might have affec-
ted the belugas' overall health and reproductive capacity.
The natural rate of recruitment of St. Lawrence belugas is only half that of the other populations in Arctic
waters, and it could be that the population of St. Lawrence belugas had already fallen below a critical level to
allow it to compensate for the natural rate of mortality. Now chemical pollution, loss of habitat, and accidental
deaths due to high traffic levels on the river may well be exacerbating an already perilous condition.
North Shore Blues and Daughters of the Sea
Jacques Cartier's description of the North Shore of the Gulf of St. Lawrence, which he reconnoitered on his
first voyage to the New World, is anything but charitable. “If the soil were as good as the harbours, it would be
a blessing,” he writes, “but the land should not be called the New Land, being composed of stones and horrible
rugged rocks; for along the whole of the north shore [of the gulf] I did not see one cart-load of earth and yet I
landed in many places . . . I am rather inclined to believe that this is the land God gave to Cain.”
