Gray whales continue to wash up dead and emaciated, but causes remain elusive.
A group of three whales, each more than 50 feet, washed ashore in a remote area of northeastern Canada on March 12, as they were about to return south from Alaska to Antarctica.
“We have no idea what killed these animals,” said Scott Vigeland, a spokesperson for the Alaska Department of Fish and Game. “There are some signs of trauma, but we have no idea of what killed them.”
While the exact cause of death is unknown, a few factors are likely to have played into their death.
In the days before the whales washed ashore in northern Quebec, a group of blue whales, that are usually found in the waters of the Bering Sea, had begun to spread north and west, likely in search of food or another breeding ground.
Blue whales feed on krill, the tiny marine crustaceans that are the main source of food for the whales.
The whales might have been feeding on the krill and became sick.
They also were not alone. A few blue whales were also found dead in the area over the past few days.
While blue whales are rare to find in the region, they are among the most common whale species to swim along coastal waters between southern Greenland and Newfoundland.
The whales were found dead and washed up on the beaches of the Mackenzie River delta, which connects the Mackenzie and Churchill rivers in northern Quebec.
“A blue whale can weigh 1,500-3,000 pounds,” said Vigeland. “And it can live for 50 years. So it’s tough to see that many whales dead from a single event.”
It is not known whether the whales died of natural causes or were killed by something from humans. The researchers involved in the study did not know what killed the whales.
A large group of killer whales, called orcas, have been spotted in the Mackenzie River delta over the past year, and they are not far from their summer breeding grounds at the mouth of the Churchill River near the Bering Sea.
As of March 28, more than 60 whales spotted in the delta were believed to be orc