Disappearance of right whales from winter breeding grounds a mystery for scientists – Nova Scotia

Scientists are at a loss to explain one of the biggest mysteries surrounding the critically endangered North Atlantic right whale — why the animals are disappearing from their usual breeding grounds off the southeastern United States. 

Usually, right whales spend the winter in their breeding grounds off Florida and Georgia. 

Before 2011, more than 200 right whales were spotted in the area each year. In 2017, there were just seven. 

“How tough can it be to find 200 whales? Apparently pretty tough,” said Jim Hain, associate scientist at Woods Hole Oceanographic Institution, located near Falmouth, Mass.

It’s just one of the many puzzles these leviathans present to researchers.

Spike in deaths

North Atlantic right whales have been in the spotlight this year after at least 14 were found dead off the East Coast of Canada and the U.S. The latest dead whale was discovered Friday morning in the Gulf of St. Lawrence.

At least 14 right whales have been found dead in Canadian and U.S. waters this year. At least 11 of those were found in Canadian waters and it’s not clear whether some of the carcasses that washed up in Newfoundland had drifted from where they were first spotted in the Gulf of St. Lawrence. (CBC)

“We’re only getting reports of a percentage of the known deaths, and there’re right whales that are dying and sinking out of sight and unreported. So the mortality figure is probably larger than we are seeing,” said Hain.

40% drop in birthrate another mystery

The birthrate of these creatures has dropped by 40 per cent from 2010 to 2016, and scientists don’t know why. 

Scientists who monitor the whales’ migration path between Canadian waters and the southern U.S. spotted just five calves born in 2017, as opposed to the 20 to 25 researchers saw every year through much of the 2000s. 

“That’s the average that we would be looking for, so it’s quite a dramatic drop-off,” said Hain, who is also project leader for the Marineland Right Whale Project in Florida and editor of Right Whale News.

The birthrate of North Atlantic right whales has dropped by 40 per cent since 2016. (Center for Coastal Studies/NOAA)

“We’re up to five calves born this year. But we have triple, just about triple, the number of mortalities. So this is a year where the deaths are three times the number of calves born, which, again, gets your attention.”

Hain said the low birthrate combined with high mortalities this year is a real concern for the…

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