Another North Atlantic right whale was found dead Thursday in Canada, meaning six of the critically endangered species have died this month in the frigid waters of the Gulf of Saint Lawrence.
The spate of deaths, a significant blow to a species with a little more than 400 animals left, prompted Canadian officials to impose more speed restrictions for large vessels in the Gulf of Saint Lawrence.
“The government of Canada takes the protection, conservation, and recovery of endangered species very seriously,” Marc Garneau, minister of Transport Canada, said in a statement.
Officials at Fisheries and Oceans Canada reported that the latest right whale was found dead on the shore of Anticosti Island in Quebec. They did not say when the whale had died.
Four whales were found dead this week alone in the Gulf of Saint Lawrence. Until 2017, when 12 right whales were found dead there, few of the animals were seen so far north.
But in recent years, as the surrounding waters of the Gulf of Maine have warmed faster than nearly any other patch of ocean on the planet, the whales’ primary source of food, a fatty, rice-sized copepod known as calanus, collapsed in their traditional feeding grounds.
As a result, scientists say, the whales have ventured to the Gulf of Saint Lawrence, where calanus was plentiful but where there were few regulations to protect the whales.
Most of the deaths in 2017 — which reduced the species’ population by 3 percent — were attributed to ship strikes or entanglements in fishing gear.
A paper published last week in the journal Diseases of Aquatic Organisms found that 88 percent of right whales, in cases where a cause of death could be determined between 2003 and 2018, had died from ship strikes or entanglements.
Of the six right whales found dead this month, Canadian officials said they have been able to determine the cause of death for just one so far.
Preliminary results of a necropsy conducted Tuesday of a female known to scientists as Punctuation, believed to be around 40 years old, suggest the mammal was fatally injured by a passing ship.
A necropsy of the first whale found dead this month, a 9-year-old male known as Wolverine, did not yield enough information for any quick conclusions about its cause of death, officials said.
They plan to conduct a necropsy of Comet, a 34-year-old male found earlier this week, on Prince Edward Island. No necropsies had been planned for the other two whales, one of which, an unnamed 11-year-old female, was considered too decomposed for such an examination.
The latest right whale was found dead Thursday drifting off Gaspé Peninsula in the Gulf of Saint Lawrence.
After the large number of deaths in 2017, Canada took action to protect the species, which can live as long as 100 years. They required ships to reduce their speeds in certain parts of the Gulf of Saint Lawrence and closed thousands of square miles to fishing.
But after no right whales were found to have died there in 2018, Canadian officials eased some of the restrictions. This year, they reduced by one third the areas where fishing had been banned during the time whales are present. They allowed fishermen to set their traps in shallower waters and lifted speed restrictions in other areas.
Now, with so many right whales dead in such a short time, environmental advocates are urging Canadian and US officials to do more.
“The loss of [six] more whales, and at least two breeding females, is catastrophic,” said Erica Fuller, a senior staff attorney at the Conservation Law Foundation, which has sued the National Oceanic and Atmospheric Administration to force it to take more aggressive action to protect right whales. “Both countries need to treat this like the emergency that it is.”
Scientists at the New England Aquarium, which closely monitors the species, say there are about 90 breeding females left.
Fuller and others urged the two countries to increase surveillance flights.
On a conference call with reporters Thursday, Canadian officials said several flights a day are now patrolling shipping lanes in the Gulf of Saint Lawrence. They said they have also expanded their surveillance flights to other areas, including the waters off Newfoundland and Labrador, in search of other large numbers of right whales.
“Governments on both sides of the border are taking the issue very seriously,” said Adam Burns, director general of fisheries resource management at Fisheries and Oceans Canada.
Canadian officials also ordered an “interim precautionary speed restriction of 10 knots” on vessels larger than 65 feet as they travel through the Gulf of Saint Lawrence in two shipping lanes north and south of Anticosti Island.
The maximum penalty for violating the speed restrictions is equivalent to about $19,000. No violations have been issued so far this year. Last year, only four citations were issued, each for the minimum of about $4,500, according to Transport Canada.
“While we commend the minister of Transport for swiftly enacting speed restrictions . . . more needs to be done,” said Patrick Ramage, director of marine conservation at the International Fund for Animal Welfare, an advocacy group based on Cape Cod. “Immediate action is needed to address all the causes of right whale mortality.”
John R. Ellement contributed to this report. David Abel can be reached at email@example.com.