Since mid-January, 25 sperm whales have been found beached on the British, Dutch and German coasts. The reasons for these strandings are being studied.
On January 24, five sperm whales are found stranded on the east coast of England, one of which was still alive. According to researcher Rob Deaville of the Zoological Society of London, they were young males that may have belonged to the same herd as the twelve juvenile sperm whales beached a few days earlier, on January 11 on the Dutch island of Texel and on the German islands of Wangerooge and Helgoland. More recently, on February 1, eight other sperm whales are found dead on a beach in northern Germany, bringing the number to 25 cetacean carcasses found in the North Sea in one month (see map of strandings).
Despite the state of decomposition of some carcasses, autopsies and sampling were performed on the most accessible specimens. In five cases, the fact that the whales were beached alive is the cause of death. The stranding must have considerably affected their internal organs and muscles under their weight, which can reach some thirty tonnes. Male sperm whales usually spend their winters in the North Atlantic waters to feed. During migration, males sometimes venture into the shallow waters of the North Sea. Researchers therefore speculate that the sandy, gentle-sloped beaches might explain the beaching of these whales, who may have been disoriented. For the other carcasses washed up on the banks, the cause remains a mystery. The sperm whales stranded in the Skegness region in the county of Lincolnshire will be picked up in the coming days. The animals have become an attraction for local residents who carve graffiti in their flesh and collect pieces of their skulls and jaws.
The causes behind mass strandings can be diverse. The presence of toxic algae in the food chain can affect whales’ health and disorient them. Acoustic disturbances such as oil exploration and the use of military sonar may affect the sound waves that cetaceans use to navigate. As pointed out here, cetacean strandings might also be attributable to the particular topography of the seabed.
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