Researchers with the U.S. government and the New England Aquarium have developed a new model they say will provide better estimates about the North Atlantic right whale population — and the news isn't good.

The model could be critically important to efforts to save the endangered species, which is in the midst of a year of high mortality, said Peter Corkeron, who leads the large whale team for the National Oceanic and Atmospheric Administration's Northeast Fisheries Science Center.

The agency said the analysis shows the probability the population has declined since 2010 is nearly 100 per cent.

"One problem was, are they really going down or are we not seeing them?" Corkeron said. "They really have gone down, and that's the bottom line."

DEEP TROUBLE | Right whale in peril

After an unprecedented number of deaths this summer, CBC News brings you an in-depth look at the endangered North Atlantic right whale. In a series called Deep Trouble, CBC explores the perils facing the right whales.

NOAA said in a statement about the new model that it's using a new statistical method to get a "clearer and timelier picture" that's less affected by changes in whale distribution, less reliant on frequency of whale sightings and better at accounting for animals that are still alive but are seen infrequently.

The agency said the number of whales declined from 482 in 2010 to 458 in 2015. That follows a period of slow recovery for the animals, which increased from about 270 in 1990, the agency said.

Right Whale Deaths

This April 2017 photo provided by the U.S. Coast Guard shows a young right whale that was found dead in Cape Cod Bay. The right whale is one of 14 to die in the United States and Canada in 2017. (R. Miller/U.S. Coast Guard via AP)

Right whales appear off the coasts of New England and Atlantic Canada every spring and summer to feed. They are also showing a worrisome, widening population gap between males and females, NOAA said. Females declined from an estimated 200 in 2010 to 186 in 2015, the agency said.

The new model is being unveiled during a disastrous year for the whales, which were hunted to the brink of extinction during the commercial whaling era. There were 14 known deaths of North Atlantic right whales so far in 2017, and reproduction has been poor, scientists say.

This summer, Transport Canada imposed a mandatory speed limit on vessels in the Gulf of St. Lawrence where 11 of the 14 right whales were found dead this year. At least two of the whale deaths this year have been attributed to ship strikes.

Deep Trouble right whales

Right whales appear off the coasts of New England and Atlantic Canada every spring and summer to feed. (Center for Coastal Studies)