The St. Lawrence beluga population would have at least doubled the individuals previously thought. However, this new assessment does not mean that the population has increased, but that the analysis of the data has improved significantly, emphasize the experts consulted by Le Devoir. In addition, this whale is still not on the mend and the high mortality rate of both females and juveniles is jeopardizing its future.
The most recent assessment of this population, presented Friday at the 2023 Beluga Symposium, concludes with an average estimate of 1,850 belugas, with a set interval of between 1,530 and 2,180 individuals. This rating is much higher than the previous one, published in 2013 and based on a population of approximately 880 animals. However, the goal of the federal government’s “reconstruction plan” is still a long way off, because it wants to increase the workforce to more than 7,000 people.
This upward correction doesn’t mean belugas are more numerous, warns Véronique Lesage, whale specialist at Fisheries and Oceans Canada. “Our analytical methods for estimating population size suggest that we have historically underestimated their abundance. It hasn’t doubled, but the methods we can use to estimate its actual size are better,” she explains to Le Devoir.
In addition, the population, which numbered around 10,000 people at the beginning of the 20th century, shows no signs of increasing or even recovering. It remains rather “stable”, emphasizes Ms. Lesage. And without scientific evidence, it is difficult to predict the “trajectory” of the next few years.
The scientific director of the Group for Research and Education on Marine Mammals, Robert Michaud, is also very reluctant to interpret the data, which has not yet been officially published by Fisheries and Oceans Canada. “The portrait we have is a little less worrying because we’ve seen a brake on the decline. But in the long term we are talking more about stabilization of the population,” he summarizes.
In terms of good news, experts have indeed noted that the decline in these resident St. Lawrence River whales has halted. The most plausible explanation links this phenomenon to the decline and then disappearance of cancer cases in belugas. In the 1980s and 1990s, analyzes of carcasses were found on the banks of the St. Waters of the River and the Saguenay River.
Thanks to recovery plans implemented over the past three decades, these cases have gradually declined, and the last cancer case was reported in 2011. Véronique Lesage sees this as an example of the “benefits” of decontamination programs. However, Robert Michaud adds that “the overall load of pollutants remains very high” in belugas, particularly due to the emergence of new pollutants.
Issue
Scientists remain “very concerned,” Ms. Lesage points out, about the significant increase in mortality among female and very young whales. The many cases of women who have died in childbirth since 2010 constitute a real “dark series”, according to Mr Michaud. Specifically, these belugas can no longer contribute to the recovery of the population. The cubs found dead in the last decade are unable to start breeding. “These premature deaths are jeopardizing the ability of this isolated population to reproduce over the next few years,” argues Véronique Lesage.
In addition, there are possible effects of global warming on the Saint Lawrence River, which are currently difficult to predict. For example, we know that rising temperatures can impact the fish stocks that belugas feed on. And we’re already seeing a significant decline in winter ice cover in the estuary and gulf. However, these arctic animals need it to protect themselves from winter storms.
The question of the constant “disturbance” of these whales in the estuary also remains relevant. Whether it is commercial shipping, boating, cruise liners, kayaking, or industrial work in the species’ habitat, all of these factors can affect foraging, communication, or shedding.
In short, emphasizes Robert Michaud, “in the long term, the Beluga has not emerged from murky waters.” A healthy population should double every 30 years, says the man who has been studying the species for four decades. In this case, however, we are only talking about “a certain degree of stabilization”.
“We had a tremendous impact on this population, first with hunting, then with pollutants and stressors. And it’s now a fraction of where it should be. She needs our good care. We do not have the luxury of changing the status of populations currently considered vulnerable. We must show wisdom and caution,” concludes Robert Michaud, recalling the importance of the Saguenay – St. Lawrence Marine Park expansion project. Quebec and Ottawa have pledged to complete the project, which will protect all of the small whales’ summer habitat, by 2025.