Beluga deaths in St. Lawrence worry whale researchers
Marine biologists in Quebec are trying to figure out what's behind the alarming increase in dead beluga whale calves washing up on the shores of the St. Lawrence River since 2008.
In 2012, researchers associated with a Tadoussac-based marine mammal research group, the Groupe de recherche et d'éducation sur les mammifères marins (GREMM), found 17 dead beluga calves either drifting in the water or washed up on shore. That's a record, according to GREMM's scientific director Robert Michaud.
In a typical year, based on data dating back to the early 1980s, fewer than three dead baby belugas washed up on shore each summer, Michaud said..
"Since 2005, we've seen an increase in the mortality of calves [and] a new kind of mortality in females — a lot of females are dying in neonatality conditions, either just before, during or after giving birth," Michaud said.
In 2008, GREMM recorded eight dead beluga calves. In 2010, scientists documented 11 deaths.
Two newborn calves were found dead in July. Scientists are in the process of determining the age of a juvenile, which died after getting stranded last weekend.
"For now, we have no simple explanation to account for [this increase]," Michaud said. "We don't know either what will be the impact of this mortality on the recovery of this population."
There are about 1,000 beluga whales living in the St. Lawrence River near the mouth of the Saguenay River — the southernmost population of belugas in the world.
It's an isolated population, far from their nearest neighbours in northern Quebec. They were nearly hunted out of existence by the 1950s, and only became protected in the late 1970s.
For years, that population was considered to be stable, and Michaud worries it may now be on the decline.
However, researchers rely on data collected by Fisheries and Oceans Canada to monitor the health of the beluga population through aerial surveys. Cuts to the federal department's budget have left holes in the data.
"2005 is the last year for which we have the numbers," Michaud said. Before that, the surveys were conducted every three or four years, dating back to 1988.
Researchers are still waiting for the analyses of data collected in 2009 — and there have been no surveys since.
"When we are tracking a small endangered population, we want to be able to detect significant change in the population," Michaud said. "If something is going wrong with the population, we should be able to detect that rapidly. Not five, 10 years afterwards."
Michaud said scientists and crew are facing difficult choices with funding cuts.
"We've been out there for 30 years, tracking belugas," Michaud said. "Most of the programs are there and running. But we're losing some now."
For the first time in 2013, researchers will not have access to data from a program that monitored the impact of contaminants on the health of belugas. That's due to the closure of the DFO ecotoxicology lab.
Michaud said the loss of that lab comes at a time when the monitoring is more critical than ever, because changes in the environment have been accelerated by climate change.
"What will be the impact on the beluga?" he asks. "Unless we're able to monitor every component of the ecosystem, we won't be able to answer that."
