“We will have done the maximum and the best possible”, estimated in front of the journalists the general secretary of the prefecture of Eure, Isabelle Dorliat-Pouzet.

This operation, which is not “winned in advance” according to Ms. Dorliat-Pouzet, will begin on Tuesday evening and will mobilize 80 people.

The cetacean, held since Friday in a lock on the Seine in Saint-Pierre-la-Garenne, about 70 km from Paris, will be placed in “a kind of hammock” then in a refrigerated truck which will transport it out of water , “on straw or another element of comfort”, bound for the coast.

A basin of seawater, in a lock in the port of Ouistreham (Calvados), was made available to receive the animal, which will remain there for three days, “the time that we organize its repatriation in the open sea and that ‘we observe his state of health,’ according to the sub-prefect.

“Today is a great day for this beluga whale and for everyone involved in its rescue,” Sea Shepherd, the ocean advocacy NGO, said on its website.

“He will be taken out of the water and transported to a salt water basin where he will be placed under surveillance and will benefit from treatment, in the hope that his illness is curable. He will then be released at sea, with, it is hoped, the best chance of survival,” added Sea Shepherd.

The NGO spoke of “an obstacle course” to manage a situation “still very unprecedented in France and for which no one is prepared”.

– Risk of “stress” –

A member of the Marineland team in Antibes (Alpes-Maritimes), who arrived Monday evening at the largest marine zoo in Europe, estimated with AFP that the operation was “out of the ordinary”, in particular in reason for the site.

The banks of the Seine “are not accessible to vehicles” at this location and “everything must be transported by hand”, explained Isabelle Brasseur. For the specialist, “the priority is to put it back in seawater”.

On Tuesday, the beluga was still feeding “very little” and its state of health was “stationary”, said Ms. Dorliat-Pouzet.

This delicate operation could induce stress in this cetacean, “which is a factor of death or discomfort for the animal” including for those in “very good shape”, she underlined.

The purpose of the operation, at the end of its stay in Ouistreham, will be to lead the beluga to the high seas, “far enough from the coast”. “And to let nature take back “its rights”, estimated Ms. Dorliat-Pouzet.

The emotion aroused by the fate of the animal led to a wave of donations, minimizing the cost of this rescue attempt.

A killer whale had already been observed in the Seine in May, between Rouen and Le Havre. She had finally been found dead and an autopsy had favored death by starvation.

“I pity this poor animal,” lamented Annie, 74, who came to see the lost cetacean in the lock of her childhood, where she came to walk before the site became an industrial area closed to the public. “We took too long to act,” said this former farmer who became a truck driver.

According to the Pelagis observatory, which specializes in marine mammals, the beluga has an arctic and subarctic distribution.

It is, according to these experts, the second beluga known in France after a fisherman from the Loire estuary had brought one up in his nets in 1948.