Open this photo in gallery A right whale and its calf are shown in a handout photo. Over the past year, fishing gear entanglements and ship strikes have killed 4 per cent of the right whale population. Georgia Wildlife Resources Division

Scientists are questioning the federal government’s decision to allow more ship traffic and underwater noise from an offshore-drilling project, warning it could inflict more harm and contribute to the extinction of the critically endangered North Atlantic right whale.

Last month, the federal Environment Minister approved an offshore-drilling project off southeast Nova Scotia that a Canadian Environmental Assessment Agency (CEAA) report says increases the risk of death and habitat quality from ship strikes and underwater noise to six at-risk whale species, including the right whale, which could be present in the project area.

The approval came less than four weeks before the federal budget earmarked spending $167-million over five years to save endangered whale species and months after the government closed the snow crab fishery two days early, temporarily lowered speed limits for vessels travelling in the Gulf of St. Lawrence and imposed new rules on the snow-crab fishery to protect the right whales.

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Unlike ship strikes and fishing-gear entanglements, noise doesn’t directly kill right whales, but it makes life more difficult for the acoustically sensitive marine mammals, said Halifax biologist Lindy Weilgart, who has spent 25 years studying underwater acoustics.

“It’s like adding more fog. If there’s a lot of traffic accidents anyway and you add more fog, you’re certainly going to make the situation worse, right,” Dr. Weilgart said.

Over the past year, fishing gear entanglements and ship strikes have killed 4 per cent of the right whale population. The bulk of the deaths – 12 of 18 – were discovered in Canadian waters in the Gulf of St. Lawrence last summer, which is approximately 500 kilometres from where the new exploratory drilling has been proposed. Only 450 right whales remain in the world, and adding to their decline is recent news that no new calves were spotted in their usual birthing grounds this year.

Dr. Weilgart said right whales don’t typically congregate in the location where the drilling is set to take place, but the distribution of right whales may be changing. Last summer, one-quarter of the world’s population was recorded in the Gulf of St. Lawrence, although in previous years, their main habitat was in the Bay of Fundy. To get to the gulf, the whales would have to migrate past the site of the drilling project, between 230 and 370 kilometres southeast of Halifax. Platform supply vessels would make the round trip between Halifax and the drilling base up to three times a week.

On Feb. 1, Environment Minister Catherine McKenna announced her approval of BP Canada’s proposal to start exploration drilling of up to seven wells on its exploration licences starting this April through to 2020, saying it’s not likely to cause significant adverse environmental damage.

In a statement, she said she based her decision on the CEAA’s 243-page report, which concluded the project may adversely affect marine mammals and sea turtles, including species at risk through supply-ship strikes and noise pollution, but that the impact would be “low to moderate” and “reversible.”

“The legally binding conditions set out in my decision statement will help keep our environment safe for future generations while ensuring the growth of Canada’s economy,” the minister said.

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The agency report notes that normal routes for platform-supply vessels would not pass near or through the right whales’ critical habitat in the Roseway Basin off southern Nova Scotia, and “the slight increase in shipping traffic due to the project is unlikely to substantially increase the probability of collisions” because BP Canada has committed to limit the speed of platform-supply vessels to 12 knots or lower in case a whale is spotted.

This may not be the only offshore drilling happening in the area. Off the west coast of Newfoundland in the Gulf of St. Lawrence, where two dead right whales washed up last summer, there are also currently three exploration licences, two of which don’t expire until 2021, according to an environmental assessment update published in 2014 by the Canada-Newfoundland and Labrador Offshore Petroleum Board.

Sean Brillant, a biologist with Dalhousie University and the Canadian Wildlife Federation, said there’s no question that adding a large industry to the centre of the ocean will further compound the dire health of the species.

“I wouldn’t go so far as to say this will be a tipping point, but what really needs to be considered here is that we’re dealing with a species that is totally on the brink,” Dr. Brillant said. “Within the next 20 years, these animals could be extinct.

“If something has been assessed as having a moderate risk to these whales, it really needs serious consideration about the value of it, and balancing that value with the very real, and very soon, loss of a large, unique species on the planet.”

Noise may not be a direct threat to right whales but it is considered a major threat to the species in addition to ship strikes and entanglements, according to the federal Fisheries and Oceans Department.

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Underwater noise drowns out right whales’ low-frequency upcalls, Dr. Weilgart said. The calls are used to communicate about food, mating, migration and take care of their calves, which remain with their mothers for a decade. The calls can travel up to 30 kilometres and are also how the whales guard against danger, such as approaching ships.

“You take away their main sense in which they orient and sense their environment, that’s a major handicap,” Dr. Weilgart said. “They can’t handle any extra stressors – none.”

Dr. Brillant said business just can’t be done the way it used to be. “Even at low levels, this noise drastically changes the behaviour of the animal and knowing so little about what’s important to these animals, we need to be very attentive to how we affect their behaviour and how they use different habitats,” he said. “Over all, we need to just stop disrupting their lives in the way that we do.”

Before any drilling can take place, BP must get authorization from the Canada-Nova Scotia Offshore Petroleum Board, which regulates the offshore oil and gas industry. CNSOPB spokeswoman Stacy O’Rourke said the board is currently reviewing BP’s proposal to start drilling one well to ensure regulatory compliance. She said the timing of a decision is unknown as it depends on what’s found in the review.

In response to scientists’ concerns that the project could further imperil the right whale, a BP spokeswoman said the company works diligently to minimize environmental impacts wherever it does business.

“Mitigation and monitoring commitments made during the environmental assessment process will be carried forward into operational plans and implemented by BP and its contractors during drilling program activities. Marine mammal observers and passive acoustic monitoring will be employed during operations,” Anita Perry said in an e-mail statement, adding that the company expects to begin the drilling in April. The company expects it will be spending $1.04-billion on the exploratory drill sites over the life of the project.

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Vance Chow, a spokesman for Fisheries and Oceans Canada, said the Fisheries Minister, Dominic LeBlanc, has yet to determine whether the project will require a Fisheries Act authorization or Species at Risk Act permit. The decisions are expected in a few weeks.

In a statement, the department added that it “has been working closely with the Canadian Environmental Assessment Agency and the Canada-Nova Scotia Offshore Petroleum Board over the last several years during the federal environmental assessment of the Scotian Basin Exploration Drilling Project, providing expert advice on fish and fish habitat, as well as on aquatic species at risk.”