ECOLOGY
HUMANS AND THE BIOSPHERE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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chemical and pollutant runoff into the ocean
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average temperatures increased in the region
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depletion of natural prey from the ecosystem
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increased levels of carbon dioxide in the atmosphere
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Detailed explanation-1: -The researchers link the whales’ alarming cancer rates to polycyclical aromatic hydrocarbons, carcinogens produced by aluminum smelters at the source of the Saguenay River. Dr. Martineau said the same contaminants help explain the higher-than-average rates of cancer among people living near the belugas’ habitat.
Detailed explanation-2: -SLE beluga and their environment are contaminated by polycyclic aromatic hydrocarbons (PAHs) produced by the local aluminum smelters.
Detailed explanation-3: -The estimated annual incidence rate (AIR) of cancer in St Lawrence beluga whales, a minimum figure of 233/100, 000 animals, is much higher than that reported for any other population of cetaceans, and is similar to that of man, and of hospitalised cats and cattle.
Detailed explanation-4: -Beluga whales are vulnerable to predation by polar bears (Ursus maritimus) when they are near ice and killer whales (Orcinus orca). Their propensity to return to the same estuaries year after year makes them vulnerable to human hunting, disturbance and pollution from agricultural and industrial runoff.