“It’s an exceptional event for the region,” said Jacky Karpouzopoulos, president of the CMNF mammal preservation association and head of its “marine stranding” team.
He said tractors would pull the massive animal, weighing 20 to 25 tonnes, away from the coastline to make sure it is not swept out by the tide, “because it could be dangerous for boats” in the busy shipping lane.
An autopsy will be carried out directly on the beach, he added.
The cause of the animal’s death was not immediately clear although experts said it could have been caused by unfamiliarity with shallow waters off France’s northern coast.
“This type of stranding is quite rare on our coast – the cetacean migration passage is usually north of Britain,” said Yoan Demassieux of the League for Protection of Animals (LPA).
The whale “died only a few hours ago. It is possible that she was surprised by the numerous sandbanks here on the beaches of eastern Calais” and “that she died of suffocation under her own weight.”
He also did not rule out the possibility that the whale was suffering from an illness.
In November, a 19-metre fin whale washed up at the port of Calais after being injured.