No calves have been seen in North Atlantic right whale breeding areas so far this winter, which raises concerns about the survival of the species, which could be completely lost in about 20 years. years.
Clay George, a biologist with the State of Georgia’s Department of Natural Resources in the United States, says right whales tend to give birth in the waters off Florida and Georgia from December to March.
But no mothers and calves were seen this year, not even during the peak period of activity in these areas in January and February.
“With each passing day, it becomes a little more disturbing,” says George. “And it is worrying especially because of the high degree of mortality observed in the last year”.
At least 17 right whales in the North Atlantic have died in Canadian and US waters in 2017, including 12 in the Gulf of St. Lawrence. Autopsies performed on seven of them showed that four died from a collision with a ship, while three died after being trapped in a fishing net.
There are about 450 right whales in the world, including about 100 females.
Fisheries and Oceans Canada has announced several measures to help North Atlantic right whales .
“When the number of deaths begins to exceed that of births, the population begins to decline. That seems to be the situation with right whales right now, “says George.
Philip Hamilton, a researcher at the Anderson Cabot Center for Ocean Life, a non-profit organization in New England, believes the absence of calves could be due to a number of factors, including lack of food.
Mr. Hamilton has been observing right whales since 1986 and says he has never seen a year without a whale.
“It’s sad,” he says. He is concerned that the situation is prolonged, or becomes permanent.
He explains that migration patterns of North Atlantic right whales have changed in the last 30 years. Many head for the Gulf of St. Lawrence, the Bay of Fundy or Cape Cod Bay in the spring and summer. The hypothesis that comes to mind is that they are heading to places where zooplankton, their main source of food, is more abundant.
Scientists suspect that food, more rare in recent years, has changed whales’ migratory patterns, affecting their quality of life and lowering calving rates. Female fertility may be reduced if they are undernourished or in poor health.
Mr. Hamilton also wondered whether the high risk of entanglement in fishing nets, or the noise generally caused by marine activity, would not make cattle more stressed, and females less fertile.
Formerly, he says, whales gave birth every three years, on average. Today it would only be once every seven years.
Clay George reports that the birth rate of Atlantic right whales has declined sharply since 2011. The number of calves observed annually increased from 20 to a dozen during this period.
On the other hand, he argues that the number can fluctuate greatly. Towards the end of the 1990s, there was only one birth one winter, then the next.
Last year, five calves were observed. It is not impossible that 2018 is ultimately an anomaly, but the trend of recent years does not bode well for the survival of the species, which is endangered.