More than 50 pilot whales died on Sunday after they have been stranded alongside a seaside on the Isle of Lewis in northwest Scotland. It was the biggest mass stranding occasion in Britain since 2011, marine rescuers say.

The coast guard, police and rescue volunteers discovered 55 whales — each adults and calves — stranded on the seaside on Sunday morning, in accordance with the British Divers Marine Life Rescue charity, which coordinated the response. By the time responders arrived on the seaside to manage first help to the surviving whales, a majority have been already lifeless, the charity added. By 3:30 p.m. native time, rescue groups determined to euthanize the surviving animals “on welfare grounds,” after it was decided that tough waves and shallow seaside situations made it unsafe to refloat them.

Only one of many 55 whales survived, a spokesman for the Western Isles Council, the native authorities, stated in an electronic mail. The whale was one among two that had been efficiently helped again out to sea. The different whale restranded itself and subsequently died, British Divers Marine Life Rescue stated.

It can take a frantic effort to avoid wasting a whale’s life after it’s stranded. Pilot whales — which come from the identical household as dolphins and porpoises — can develop to 24 ft in size and weigh as much as 6,600 kilos. When beached, they’ll steadily crush themselves or their blood circulation might be minimize off, releasing toxins that poison the animal, marine biologists say.

“They were likely all in the same family, a unit traveling together for decades,” stated Daren Grover, normal supervisor of Project Jonah New Zealand, a charity that responds to whale strandings in New Zealand.

The Cetacean Strandings Investigation Program from the Zoological Society of London has logged over 17,000 stranded cetaceans, referring to the category of animals that features pilot whales, dolphins and porpoises, since its founding in 1990. Last fall, 230 pilot whales have been beached on the western coast of Tasmania.

In 2011, roughly 70 pilot whales have been caught in shallow waters off the coast of Sutherland in Scotland. But a fast response led to the profitable refloating of 20 of the whales. This time, the rescue efforts confronted “major obstacles” from the outset, stated Dan Jarvis, director of welfare and conservation on the rescue charity.

“They basically found one of the worst places to strand: in a remote island on a remote beach on a Sunday,” he stated.

Roughly 30 miles from the northwest coast of Scotland, the Isle of Lewis is accessible solely by ferry or airplane. The rescue charity was quick on volunteers and tools was scarce. With no cellphone sign inside a two-mile radius of the seaside, new communication channels wanted to be arrange. It amounted to a large-scale coordination effort of greater than 50 responders together with volunteers, the coast guard, the police and the Scottish Fire and Rescue Service.

The charity stated the whale pod may need adopted one of many whales ashore after it had issue giving beginning. “Pilot whales are notorious for their strong social bonds,” the charity’s assertion stated. “So when one whale gets into difficulty and strands, the rest follow.”

Pilot whales, that are extremely social creatures, are the species “most prone” to changing into stranded, in accordance with Scottish Marine Animal Stranding Scheme, or S.M.A.S.S. But the causes of their unintended isolation differ extensively, marine biologists say. Whales might be thrown off by sonar or led astray by one sick or injured whale.

On Monday, a crew from S.M.A.S.S. was working to gather tissue samples to find out the reason for the stranding. A last conclusion might take weeks or months to find out, Mr. Jarvis stated.