Sick killer whale stranded in France’s Seine river dies
An orca swims in the Seine river at Duclair in Normandy, France after straying into the river from the sea and swimming from Le Havre to Rouen on May 26, 2022. © Pascal Rossignol, Reuters file photo

A gravely sick orca which became separated from its pod and swam dozens of miles up the river Seine in France has died of natural causes, the campaign group Sea Shepherd said on Monday, after attempts to guide it back to sea failed.

"We found him late this morning," Lamya Essemlali, head of Sea Shepherd France, told Reuters.

Scientists concluded over the weekend that the 4-meter (13-foot) killer whale was terminally ill and likely suffering from mucormycosis, a rare fungal infection.

During an attempt on Saturday to lure the whale back out to sea with a drone emitting orca sounds, the animal behaved incoherently and emitted distress calls, local officials said.

By Monday, it resembled nothing more than "a ghost of an orca", Essemlali said, and it died before any attempt at euthanization could be made.

The whale's body will be moved to the shore of the river and an autopsy will be conducted, local officials said in a statement.

The orca was first spotted at the mouth of the Seine on May 16 between the port of Le Havre and the town of Honfleur in Normandy, before it swam miles upstream west of the city of Rouen.