Marine biologists on Tuesday expressed deep concern over a spate of whale deaths on France’s western shores, amid suspicions the emaciated creatures were victims of a viral epidemic, starvation, or both.
Seven of the huge marine mammals have ended up beached in Brittany and further up the northwestern coast of France in the past six weeks. The latest was found on Monday.
All the victims are fin whales, the second-largest species after the blue whale.
The most recent fin whale corpse was found on Saturday near Saint-Hilaire-de-Riez. It measured nearly 16 metres and weighed an estimated 10 tons.
Researchers have had to resort to mechanical diggers and long knives to dissect the rotting carcasses, which can explode if left unattended due to a build of gasses.
Officials posted guards near the carcass at the weekend to keep curious locals at bay.
None of the cetaceans appears to have been the victim of a collision with a ship or fishing nets. One appears to have died of natural causes.
All the others suffered from the same apparent condition, according to Willy Dabin, a researcher from the Pelagis Observatory at La Rochelle, western France, who is in charge of handling beachings and has examined several of the whales.
“All the organs are in relatively good condition except the heart and lungs, which display swelling and important congestion which lead us to suspect a viral infection,” he told the Telegraph, saying distemper was the most likely culprit.
However, he said a viral epidemic did not appear to the be the sole cause of death as “they are all very skinny”.
“Viruses like distemper kill very fast and wouldn’t normally give the whale time to lose so much weight. Even if we do find this virus was present, we need to look further,” he said.
“We are wondering whether this migratory whale has suffered from environmental problems, from a form of famine that affected the creatures’ health over some time paving the way for pathogens to take hold and speed up the spike in deaths,” he said. “It may not have found enough food in its zone.”
The whales roam over a vast area up to 400km off the western coast of France, around Spain, Ireland and the UK, and have a particular penchant for feeding up the continental slope which rises towards the French coast from the deep abyssal plain.
Samples from all the dead whales have been sent to the University of Liège in Belgium for analysis and results are due in the coming days.
“For now we have many questions and few answers,” he said, adding that he had issued a call for help to all European whale experts for data suggesting there may have been a “collapse” in the food chain.
“One reason could be major upheaval due to climate change,” he said.
Regarding the issue of viruses, he said they “always express themselves for a reason, which goes for humans too – either it’s a question of population density or the weakness of organisms or both.”
“We’re leaving no stone unturned because it’s deeply concerning.”