The Saguenay River may be getting too loud for beluga whales to communicate with each other, causing calves to lose their mothers and putting their lives at risk.
An increasing number of whale carcasses that turn up in Quebec belong to pregnant females, mothers and newborn calves. Experts in the area called the situation an "epidemic."
Of the 14 carcasses recovered in 2015, six were newborn calves and three were pregnant. In 2014, 11 beluga carcasses were recovered, and six of them were babies. In 2013, 17 dead belugas were found, and four of them were babies.
That has prompted a team of researchers affiliated with the Group for Research and Education on Marine Mammals (GREMM), based in Tadoussac, to spend the summer exploring what is behind the spike in whale deaths.
Between a city street and a jackhammer
The researchers are working from the theory that beluga calves have soft calls, which may be drowned out by the noise from ships, ferries and boats in the Saguenay and St. Lawrence rivers.
Belugas rely on their hearing to "see," so too much noise pollution could hamper efforts of female beluga to find their offspring.
"In fact, the noise of boat motors in certain areas of the St. Lawrence is so loud that, if humans were exposed to the same sound levels, they would be required to wear safety equipment," Peter Scheifele, a professor at the University of Connecticut, observed back in 1998.
He compared the noise levels then in certain parts of the St. Lawrence to somewhere between a city street and a jackhammer.
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Drones and underwater microphones
The director of the marine research group at GREMM, Robert Michaud, said there has been a recent increase in traffic around Cacouna, about 200 kilometres north of Quebec City, which could be having a negative impact on mothers and their offspring.
GREMM is using drones and underwater microphones to investigate their hypothesis.
"This strategy will help us understand in what context calves use their cries and how those cries can be masked by the passing boats," Michaud said.
Quebec's $9-billion maritime strategy, which seeks to invest in projects along the St. Lawrence River, worries Michaud. He hopes the government will back protected areas for the belugas along with any economic development.
The organization is asking the provincial and federal governments to create a protected area in the river that will be free from noise.