For centuries beluga population of the St. Lawrence Estuary did not demonstrate any significant reduction. However, nowadays the specie is disappearing from the location rapidly and there are many reasons for that. Pollution, maritime traffic, and diseases might be influential factors to cause this problem, but the climate change poses the greatest threat.
Currently volunteers keep monitoring beluga and the conditions they live in St. Lawrence Estuary. Numerous analysis and examinations were conducted and it was determined that nearly 40 per cent of the beluga deaths were caused by various diseases, infections and bacteria. Lungworms are the most damaging for the specie and representative of the animals can carry more than 12, 000 of them, affecting its airways, and experiencing problems with air breathing and diving.
Other parasites which are the most frequently indemnified to cause death are morbillivirus, marine Brucella, etc. The last one causes reproductive problems in beluga, making their population even lesser. Moreover, beluga does not have any antibodies to fight various viruses, so they die because of infections more frequently than seals, for example.
Contaminants are also among the factors to cause death in the animals. DDT and PCBs have been eliminated by the government, while many new chemicals still affect beluga.
Despite the fact that these factors and contaminants pose a great threat, the greatest risk is created by the climate change. It is suggested that past predators might return to the St. Lawrence Estuary and with no ice beluga will not have any opportunity to escape killer whales.
The climate change also affects beluga’s food supply because the conditions of oceanography are changed, so there might appear new competitors who are also expected to bring new infections (What’s killing the white whales of the St. Lawrence?).
Thus, it is possible to conclude that belugas face numerous factors which reduce their population, such as infections and contaminants. However, the climate change is the most serious threat and it is expected to take away beluga’s opportunity to become protected from killer whales or find any food.
Works cited
What’s killing the white whales of the St. Lawrence? Fisheries and Oceans Canada. 7 March, 2011. Web. 26 Oct., 2012, < HYPERLINK "http://www.dfo-mpo.gc.ca/science/Publications/article/2007/27-07-2007-e ng.htm" http://www.dfo-mpo.gc.ca/science/Publications/article/2007/27-07-2007-en g.htm >.
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