St Lawrence Beluga Whale Population on Road to Extinction
Photos and story by Robert J. Galbraith for the Montreal Gazette, October 2013
Tadoussac, Quebec—Researchers gathered in St. John’s, N.L., this month for a series of Fisheries and Oceans Canada meetings to try to discover the cause of a huge rise in the number of infant beluga whales being found dead in and along the St. Lawrence River during the last five years.
They concluded that not only are the beluga calves dying in record numbers, but during the last decade, the St. Lawrence River Estuary (SLE) beluga population has fallen from 1,000 to about 900, after four decades of relative stability in the population. But no one really seems to know for certain how fast the population is declining, or why. What they do know is that the future is bleak for the SLE beluga — one of the most contaminated and threatened marine mammals in the world.
In 1982, when researchers began studying this population of belugas — one of seven distinct populations in Canada — records showed an average of two or three dead calves might have been found each year, and that trend continued up until the early 2000s. But eight calves were found dead in both 2008 and 2010 — an alarming increase, according to researchers. Last year, a staggering 16 newborn bodies were recovered from the St. Lawrence and its shores.
It was hoped the October meeting could shed light on whether these mysterious deaths were an isolated series of events or the beginning of a disturbing trend. The conclusion was that it turned out to be the latter.
“The situation is very serious and tragic, and at this time, the picture is bleak for the St. Lawrence beluga,” said Robert Michaud, co-founder and director of research for the Tadoussac-based Groupe de recherche et d’éducation sur les mammifères marins (GREMM), one of numerous organizations — including the Université de Montréal and Parks Canada — that team to study the whales.
“This population was considered stable, but as of the October meetings, and after combing over all the available data, we believe the population is declining and has been since these phenomena of infant deaths started occurring around 2000. This is when we started to see a series of major changes in the ecosystem of the St. Lawrence,” the scientist said.
The SLE beluga was the catalyst of a very broad mobilization to clean and protect the St. Lawrence River during the early 1980s.
“Decontamination, stricter regulation of industrial emissions, creation of the Saguenay/St-Laurent Marine Park, a ban on exploration and exploitation of hydrocarbons in the estuary, many initiatives have originated from the alarm signal we launched about the beluga and the state of the St. Lawrence, its richness and fragility,” Michaud said, adding that the SLE belugas have reached a crucial point in their existence.
“Because it is such a small resident population, we may be looking at a very critical crossroads in the continued survival of the SLE beluga. This is extremely bad news,” he said.
“And at the end of the meetings, we realized the situation is alarming. The exercise failed to pinpoint the cause of mortalities in 2012, but it revealed a deeper problem: The population we considered stable up to now, has been declining since the early 2000s.”
Scientists can’t put their finger on a single culprit behind the calves’ deaths and drop in overall numbers, but agree it may be a combination of factors. Some of these include climate change, (such as warming water and reduced ice coverage), noise pollution from boat traffic, a lack of diversity in the breeding pool, a host of life-threatening viruses and bacteria, parasites, toxic algae blooms (evidence of which was found in some of the 2008 beluga carcasses), chemical contamination of prey and habitat loss.
Unlike other whale species found in the St. Lawrence Estuary, the SLE beluga is non-migratory. Any carcinogens or other contaminants dumped or leaked into the Great Lakes or the St. Lawrence end up flowing through the belugas’ habitat and can contaminate the whale population. The beluga can’t escape the contamination, as it is sedentary (other whales leave the region for extended periods during the autumn and winter, and therefore are exposed to less of the contaminants).
“Last year, when faced by these quite spectacular moralities, it raised the question of what is going on and if it would have any effect on the population trajectory,” Michaud said. “This forced researchers to go back and try to understand what was going on.”
“There is no smoking gun that can be easily described,” Michaud said. “Perhaps we are looking at a few causes coming together, like a perfect storm of events. What we discovered is actually very much more distressing than we expected.
“Inevitably, what will kill them off and take the population down will probably be related to climate change,” the researcher said. “Ice thickness in the estuary has been slowly decreasing for at least the last 10 years, and this lack of ice can change beluga behaviour, birthing success and have other complications. Climate change is a huge issue, and research has shown that changes in environment correlate with changes in animal populations, and perhaps this is occurring here.”
In North America, PCBs, DDT and other toxins took their toll on belugas and by 1970, cancer became the leading cause of death in the SLE population. But since the manufacturing and importation of these toxins were banned in Canada and the U.S., toxicity levels in the mammals’ bodies have stabilized and even showed a slight decrease. However, the SLE beluga whales remain among the most contaminated marine mammals in the world, according to a Fisheries and Oceans Canada news release last October.
And there is a newer class of chemical that might threaten the belugas’ future. PBDEs are used as flame retardants in such everyday items as furniture, computers, cars and toasters. They have increased dramatically in the environment since the 1980s, but their use has since been regulated in Canada. These compounds are known to disrupt thyroid gland activity, which is crucial for mammals during the birthing process.
Scientists suspect PBDEs may be linked to the increased mortalities, but there is no concrete evidence. “It’s another stressor in the system that has accumulated in the belugas’ body tissues,” Michaud said.
Véronique Lesage is a leading researcher with Fisheries and Oceans Canada who specializes in whales and ecology, and is in the first year of a three-year study looking at pregnancy rates in SLE belugas.
“We all agree there has been a decline, but the rate of that decline is uncertain,” she said. “Using all the data and based on a model, the present population would be about 900 individuals.
“Even if the population of belugas in the St. Lawrence was considered stable or increasing slightly before the 2000s, it must be remembered that the growth rate was well below what is normal for a (healthy) population of belugas. The population was therefore already subject to pressures that limited its growth, and these pressures have not disappeared.”
Stéphane Lair, a professor with the Université de Montréal’s faculty of veterinary medicine, has directed beluga necropsies for 30 years at the faculty and has noticed one recent change in the mammals.
“After conducting necropsies on some of these calves (from 2008 to 2012), the only finding is the presence of subtle changes in the lung, suggesting some levels of distress during the birthing process,” the pathologist said. “We feel that the mortality of these calves (was related) to their failure to thrive or nurse, either because they were too weak or because their mother was too weak, sick or dead.”
But, Lair noted, the cause of the calves’ problematic births can’t be conclusively determined.
“The mechanics of why newborns are dying is where it becomes hazy,” Michaud agreed. “But the changes we see in the environment are clearly evident. That’s for certain.”
Further complicating the situation is the fact that, during the past decade, there has been a large increase in the number of pregnant belugas that have been dying before, during and after giving birth. Lesage is involved in a study of pregnancy rates and hopes to get a clearer understanding of the cause of these deaths.
Scientists said they’re witnessing just the tip of the iceberg, concerning whale mortality rates, and that the actual number of deaths is in fact much higher. Most dead whales are never recovered, because the carcasses sink or disappear into the vast estuary. Those that are found are transported to the Université de Montréal’s faculty of veterinary medicine in St-Hyacinthe.
Researchers are not only trying to make sense of a long list of potential physical threats; they also have to contend with federal budget cuts and department closings, which impede consistency in the studies and leave gaps in the research.
“For about 30 years, we’ve been able to maintain a pretty intense study of the beluga,” Michaud said. “However, during the last 10 years it has become more and more difficult to maintain the same level of monitoring. The frequencies at which aerial surveys have been conducted have been reduced, and that is a major impediment to our research.”
While the budget cuts hamper research, they also reduce the amount of information getting out to the public. Part of Fisheries and Oceans Canada’s Recovery Plan for the belugas is that the public and media be kept abreast of the mammals’ struggle and this information be made available. However, budget reductions have led to the loss of important information links.
In 2012, for example, GREMM was forced to discontinue the English translation for its informative website because of budget cuts. So much of the recent information on the beluga is only available in French, hindering researchers, media and the public outside Quebec who want to know about the whales.
“Every year, we are not sure if the surveys will be funded,” Michaud said. “We had the closing of an ecotoxicology lab that analyzes contaminants in tissue samples. So we have to be out there and have a more formal commitment from the federal government to keep the studies going. We have to take the situation more seriously, as we are currently losing the capability to understand what is going on.”