ANKARA 

A beluga whale that was lifted out of France's Seine River was put to death after an extraordinary rescue effort failed to improve its precarious health, authorities said on Wednesday.

“Despite an unprecedented rescue operation for the beluga, we are sad to announce the death of the cetacean,” the prefect of the Calvados department said on Twitter.

“It is with heavy hearts that we announce that the beluga did not survive the translocation which was risky, but essential to give an otherwise doomed animal a chance. Following the deterioration of his condition, the veterinarians took the decision to euthanize him,” tweeted NGO Sea Shepherd, which was involved in the rescue operation.

Earlier on Wednesday, the whale was removed from the water following an ambitious rescue operation at the Saint-Pierre-la-Garenne basin in Eure, Normandy.

It was later transferred to a refrigerated truck to be carried 160 km away to the port of Ouistreham in Calvados. There it was due to spend three days in the seawater basin under observation, in preparation for its release. But during the journey it developed breathing difficulties.

The beluga, which is found in the freezing waters of Arctic and sub-Arctic seas, had strayed in the English Channel and was stuck in the Seine river for a week. Its health had deteriorated after it refused food.

In May, an ailing 4-metre (13-foot) orca, spotted in the same river, died after an attempt to guide it back to the Channel failed.