Provincetown (USA) (AFP) – After hours at sea and some false hopes, here they are: three critically endangered North Atlantic right whales appear in front of a research vessel in a bay near Boston in the northeastern United States.
The captain of the Shearwater turns off the engine, and three marine biologists are busy taking notes and photographs to identify and track the whales and their injuries. Work is needed to protect this species, which, according to experts, there are only 336 individuals left.
Destroyed by 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 endangered even more than tigers or black rhinos.
“Unfortunately, their population has been declining since 2010,” said Kristi Hudak, head of the Center for Coastal Research, based in Provincetown, the fishing port in Massachusetts where the explorers’ boat left.
Using a small plane and drones equipped with cameras launched from a second boat, these scientists are trying to trace the reproduction of Eubalaena glacialis, their Latin name. Because the new rules on the speed of ships in protected areas or on fishing nets did not calm them down.
Climate change, by warming the waters of the North Atlantic, is depleting the stocks of small crustaceans Calanus finmarchicus, one of the elements that make up plankton and are necessary for the diet of southern right whales.
It is around Cape Cod, the peninsula at the tip of which is the very touristy Provincetown, that this species is often observed, the water warming up more slowly than anywhere else.
Here, biologists study, in particular, plankton by taking water at different depths, which allows them to estimate the dates of the arrival and departure of whales.
For hundreds of years, they have been a favorite prey of fishermen – Vikings, Basques, English, Dutch, and then Americans – because of their oil, used in lamps, and their whalebone, very practical before the advent of plastic.
According to David Leist, author of a book on the subject, the species numbered up to 20,000 prior to the start of large-scale fisheries. It was then destroyed in the early 20th century.
A rise in births in the early 2000s led to a peak of 483 animals in 2010, but that figure, which has since fallen, plummeted in 2017 due to the accumulation of deaths.
“Fourteen right whales died in a very short time as they made their way to the Gulf of St. Lawrence, where they rarely go and where they have been hit hard by the crab fishery,” says Charles Mayo, founder of the research center on the coast.
Climate change appears to be the reason for this shift in their foraging ranges due to lack of sufficient prey.
And because whales are already so rare, even a few deaths could be enough to trigger a dangerous decline in the species.
“It’s very worrying because their reproductive rate is very low and their mortality rate is very high,” said Charles Mayo, who was part of the first team to free the whale from its entangled net.
These sea giants breed in the spring and summer before traveling 1,000 miles south to give birth. This cycle, which typically lasts three years, now averages three to six years, according to the US National Oceanic and Atmospheric Agency.
Specialists believe that the stress that females are subjected to, in particular, due to entanglement in ropes or even ocean noise caused by human activities, is behind this decline in fertility.
– Playful whale –
These whales, the third largest in the marine kingdom, live as long as humans, sometimes up to a century.
Stocky – and therefore black – they are distinguished by the fact that they have no dorsal fin and are adorned with calluses on their heads covered with tiny crustaceans called “whale lice” that live in apparent symbiosis with their hosts.
Alerted by their colleagues flying over the area, the researchers find more whales, including a calf playing to imitate its mother, and then a group of cetaceans coming together on the surface to socialize.
During this type of gathering, Christy Hudak explains, the whales “turn over while touching others. The main purpose is to breed, but also to interact with other right whales. It’s not just for sex.”
The sea trip will allow watching ten whales, including two mothers with calves, as well as a socialization group. The survival of the species is far from guaranteed, but researchers allow themselves to hope.
New technologies aim to reduce entanglement in fishing nets by making ropes more brittle or by developing traps that can be brought to the surface by remote control without line.
Better acoustical detection of whales could also allow quick response to their presence by establishing speed limit zones for boats.
But it’s vital, Christy Hudak emphasizes, to raise awareness and build public support to protect “these incredible creatures.”
© 2022 AFP