The captain of the Shearwater cuts the engine and three marine biologists are busy taking notes and photos to identify and track the whales and their injuries.

Essential work for the protection of this species of which there are only 336 individuals left according to experts.

Decimated by the now banned whalers, the right whale, or right whale, of the North Atlantic remains today under the threat of collisions with boats and fishing nets.

This species of large marine mammals - about twenty meters long and weighing 70 tons - is even more in danger of extinction than tigers or black rhinos.

"Unfortunately, their population has been declining since 2010," said Christy Hudak, head of the Coastal Research Center based in Provincetown, a fishing port in Massachusetts, where the researchers' boat left.

Using a small plane and drones equipped with cameras launched from a second boat, these scientists are trying to follow the reproduction of Eubalaena glacialis, their Latin name.

Because the new rules on the speed of ships in protected areas or on fishing nets have not reassured them.

Climate change, by warming the waters of the North Atlantic, is depleting the stocks of a small crustacean, Calanus finmarchicus, one of the elements constituting plankton and essential to the diet of right whales.

A whale and her calf appear on the surface in Cape Cod Bay, off Massachusetts, April 5, 2022 Joseph Prezioso AFP

It is around Cape Cod, the peninsula at the tip of which is the very touristy Provincetown, that the species is often observed, the waters warming up less quickly than elsewhere.

Here, biologists study plankton in particular by taking water at different depths, which allows them to estimate the dates of arrival and departure of whales.

Decimated

They were for hundreds of years the favorite prey of fishermen - Vikings, Basques, English, Dutch and then Americans - for their fat, used in lamps, and their baleen, very practical before the arrival of plastic.

A member of the scientific expedition photographs a whale in Cape Cod Bay, off the coast of Massachusetts, April 5, 2022 Joseph Prezioso AFP

The species numbered up to 20,000 individuals before the arrival of large-scale fishing, according to David Laist, author of a book on the subject.

It was then decimated at the beginning of the 20th century.

A rise in births in the early 2000s led to a peak of 483 animals in 2010, but the figure, which has since fallen, plunged in 2017, due to an accumulation of deaths.

“Fourteen right whales died in a very short time, as they moved to the Gulf of St. Lawrence,” where they rarely go and where crabbing has hit them hard, says Charles Mayo, founder of the research center on the coastline.

Climate change seems to be the cause of this shift in their feeding area, due to a lack of sufficient prey.

And with right whales already so rare, even a handful of deaths could be enough to trigger a dangerous decline for the species.

"It's very worrying because their reproductive rate is very low, while the mortality rate is very high," said Charles Mayo, who was part of the first team to free a whale from a net. in which she had become entangled.

A member of the scientific expedition takes a plankton sample in Cape Cod Bay, off the coast of Massachusetts, April 5, 2022 Joseph Prezioso AFP

These marine giants breed in spring and summer, before traveling up to 1,000 miles south to give birth.

This cycle, which normally lasts three years, currently spans three to six years on average, according to the US National Oceanic and Atmospheric Agency.

Specialists believe that behind this declining birth rate lies the stress suffered by females, in particular because of entanglements in ropes or even ocean noise caused by human activities.

- Playful whale -

These whales, the third largest in the marine kingdom, live as long as humans, sometimes up to a century.

Marine biologist Christy Hudak searches for whales using binoculars during a scientific expedition in Cape Cod Bay, off the coast of Massachusetts, April 5, 2022 Joseph Prezioso AFP

Stocky -- and black, therefore --, they have the particularity of not having a dorsal fin and of being adorned, on their heads, with calluses covered with tiny crustaceans nicknamed "whale lice", living in apparent symbiosis with their hosts.

Warned by their colleagues flying over the area, the researchers found new whales, including a calf playing to imitate its mother, then a group of cetaceans close together on the surface to socialize.

During this type of gathering, explains Christy Hudak, the whales “roll over, touching others. The main objective is to reproduce but it is also to interact with other right whales. it's not just for sex."

The sea trip will have allowed the observation of ten whales, including two mothers with their calves, and a socialization group.

The survival of the species is far from certain, but researchers allow themselves to be hopeful.

New technologies aim to reduce entanglement in fishing nets, whether by making the ropes more fragile or by designing traps that can be brought to the surface by remote control without a line.

Better acoustic detection of whales could also make it possible to react quickly to their presence by establishing limited speed zones for boats.

But it is vital, stresses Christy Hudak, to raise awareness and get the public's support for the protection of "these incredible creatures".

© 2022 AFP