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The years go by and are worryingly similar in terms of recorded mortalities of St. Lawrence belugas. In total, 17 carcasses were found last year, the majority of which were females. A phenomenon that concerns experts on this endangered cetacean.
According to data just published by the Quebec Emergency Network for Marine Mammals (RQUMM), 10 females were among the belugas recorded in 2023, compared to 6 males. Another carcass could not be identified.
“The high proportion of females in the carcass count is of great concern to the scientific community. The cause of the death of the females is also a source of concern,” underlines the RQUMM.
In recent years, numerous cases of dystocia — complications during birthing — have in fact been recorded as part of the carcass recovery and necropsy program at the Quebec Wild Animal Health Center in Saint-Hyacinthe.
A report produced by the team of Stéphane Lair, full professor at the Faculty of Veterinary Medicine at the University of Montreal, has already concluded that difficult birthing had become “the most important cause of mortality of adult female belugas in the Saint Laurent”.
“Nevertheless, the reasons behind these complications still remain a mystery. A significant number of stressors currently affect St. Lawrence belugas and several could be responsible [de ces complications]», underlines the RQUMM.
For example, it is possible that the physical condition of female belugas does not allow them to have the energetic capacity to give birth. Certain chemical contaminants could also affect their health. For several years, researchers have suspected in particular that products used as flame retardants in various objects (textiles, computers, paint, etc.), but which are also endocrine disruptors, could harm birthing.
During 2022, 12 belugas were found dead drifting or on the banks, including 7 females. And no less than 19 individuals were found dead in 2021, including 6 newborns. Over a period of nine years, from 2016 to 2023, the toll reached 117 carcasses.
Threat
In the 1980s and 1990s, analyzes of carcasses found on the banks of the St. Lawrence revealed that these animals, which can live more than 60 years, had extremely high cancer rates, due to water contamination. of the river and the Saguenay river. Thanks to sanitation plans put in place over three decades, these cases have gradually decreased and the last case of cancer was reported in 2011.
The species nevertheless faces other threats, including noise pollution, the impacts of global warming and maritime traffic.
The Société des traversiers du Québec (STQ) is evaluating its options for the potential relocation of the ferry which provides the connection between Bas-Saint-Laurent and Charlevoix. The port of Gros-Cacouna, located in a key habitat for the beluga, is planned to accommodate it.
The Legault government also authorized last year the STQ to dredge and discharge sediments for the next ten years in an essential habitat of the St. Lawrence beluga, in the Rivière-du-Loup region. However, there is no scientific study to assess the effects of dredging operations on this endangered species.
The most recent assessment of this population, presented Friday during the 2023 Beluga Symposium, concludes at an average estimate of 1,850 belugas, with an interval established between 1,530 and 2,180 individuals. The objective of the federal government’s “recovery plan” is, however, still far away, since it aims to increase the number to more than 7,000 individuals.