HALIFAX -- For years, fishermen off the U.S. east coast have faced tight restrictions on fishing gear and vessel speed restrictions to ensure their activities do not harm marine mammals, including the endangered North Atlantic right whale.

But in Canada, it was only after right whales began turning up dead in large numbers in 2017, many of them tangled in fishing gear and struck by vessels, that authorities brought in emergency measures, and by then it was too late to avoid a record number of deaths.

After another summer of high mortality for right whales in Canadian waters, questions are being asked about whether Canada's slow response to the crisis could still be taking a toll. And with a deadline approaching for exporting countries to respect new marine mammal protection legislation in the United States, the inaction could end up harming Canadian fisheries.

Sean Brillant, a senior conservation biologist at the Canadian Wildlife Federation, says Canada's response prior to 2017 -- and the 20 right whales found dead in Canadian waters in the past three years -- could be a concern for Canadian fisheries. He said the conservation of marine mammals is not only a "feel-good" issue but a political one.

"The conservation of these whales is relevant to the conservation and sustainability of our fisheries," Brillant said in an interview. "Within the conservation and scientific community, we'd seen this coming for some time."

Brillant said the United States legislated in 2016 to prevent the entry into the country of seafood that does not meet strict standards around the incidental killing of other species, including whales.

The new legislation added provisions under the U.S. Marine Mammal Protection Act, giving countries that export seafood to the United States five years, beginning Jan. 10, 2017, to comply with the new rules.

"Harvesting nations are expected to develop regulatory programs to comply with the requirements to obtain a comparability finding during this time period," the legislation says.

That means a harvesting country must prove it has adopted regulations about incidental mortality and injury of marine mammals in its commercial fishery comparable "in effectiveness" to the U.S. regulatory program.

It must also provide detailed data such as the number of vessels, gear type, species, fishing area, and death and injury rates of marine mammals. It is then up to the United States to determine if the measures to protect marine mammals are sufficient.

Brillant says the comparability finding is key, but it remains uncertain how it will be evaluated by the U.S. government.

Asked whether the eight North Atlantic right whales found dead in Canadian waters this summer could affect a decision on Canada's compliance with the new regulations, the National Oceanic and Atmospheric Administration -- the U.S. government agency that oversees ocean resources and habitat -- declined to comment.

John Ewald, NOAA's director of public affairs, said that Canada is expected to submit a progress report on "efforts to mitigate marine mammal bycatch in their export fisheries" by Sept. 13.

Brillant says there was evidence the endangered marine mammals were heading into the Gulf of St. Lawrence to feed prior to 2017.

A 2018 study entitled "Mass human-caused mortality spurs federal action to protect endangered North Atlantic right whales in Canada," which Brillant co-authored, says the government's reaction to the dead whale crisis in 2017 was unprecedented -- but it came too late.

Commercial fisheries in Canada are obliged to incorporate marine conservation strategies -- including objectives to protect marine mammals like the right whale -- in their fisheries management plans, Brillant's study says.

Despite several studies prior to 2017 by scientists -- including some who worked for the DFO -- pointing to an increased presence of right whales in the Gulf of St. Lawrence and the threat posed by fishing gear, "no mandatory regulations for fisheries had been implemented to mitigate potential interaction between fishing gear and right whales," says Brillant's study.

On the contrary, in 2017, the Canadian snow crab fishery saw a significant increase in quota in the Gulf of St. Lawrence, which meant more traps -- and more rope -- were used.

As the number of dead whales rose that year in Canadian waters, the federal government moved to protect the animals, reducing commercial shipping vessel speeds and closing a snow crab fishery, the study says. But by the time the measures were implemented, the damage was done.

"The pace of this process was commendable, but most of the mortalities and injuries had already occurred by the time the measures were in place," the study says. When the snow crab fishery in the region was closed, after eight whale carcasses and four live entanglements were discovered over 46 days, fishermen had already caught their annual quota, the study notes.

The Department of Fisheries and Oceans, one of four government departments responsible for the management of human activities that can harm marine mammals, says it was aware of the increasing presence of right whales in the Gulf of St. Lawrence before 2017.

"Canadian and U.S. research groups have been working together to monitor and study right whales in Canada and the U.S. for decades," Robin Jahn, a DFO communications officer said in an email. "Monitoring and research in the Gulf of St. Lawrence increased significantly since 2017. Such research has contributed to the understanding of the species, its natural history, its habitat use and patterns of injury and mortality before and since 2017."

Jahn said planning and implementation under federal legislation protecting species at risk had begun for the right whale before 2017, involving input from Indigenous groups, representatives of the fishing and shipping industries and other experts.

But in 2018 Canada's auditor general published a report on the protection of marine mammals, looking as far back as January 2012, and concluded the government had not adequately tried to protect the whales .

"Overall, we found that Fisheries and Oceans Canada, Environment and Climate Change Canada, Parks Canada, and Transport Canada had not fully applied existing policies and tools to proactively manage threats to marine mammals from commercial fishing and marine vessels, such as entanglements, bycatch, depletion of food sources, noise and disturbance, oil spills, and collisions with marine vessels," the report said.

In April 2018, the Canadian government, with the help of scientists and non-governmental organizations, implemented mandatory regulations -- fishery closures in areas with a high number of whales, reduced snow crab quota, shipping lane management and reduced vessel speed limits.

Marine mammal protection in Canada is covered in the Fisheries Act and the Species At Risk Act, introduced in 2003. Patrice McCarron, the executive director of the Maine Lobstermen's Association, says some U.S. restrictions date back to the 1970s, and Canada has lagged behind when it comes to regulating fisheries to protect whales.

"All U.S. fixed gear fisheries from Maine to Florida have gear modifications in place so that if a right whale did encounter the gear, we are increasing the likelihood that the whale will get out of the gear without being seriously injured or killed," McCarron said. Canada does not have those same regulations, she said.

"We have vessel speed restrictions in place along the entire U.S. coast, either static areas or dynamically if whales are sighted," McCarron said.

"That plan has been in place for probably 10 years and has had significant positive impact on reducing vessel strikes here in the U.S."

Brillant's study concludes that if the Canadian government had taken actions in response to the scientific evidence presented to them before 2017, the right whale fatalities that year would have been significantly reduced.

"Conservation action is not always drastic, but prolonged ignorance of evidence makes drastic, crisis management action more likely," it says.