Mass stranding of whales on Scottish beach caused by loyalty to their pod, report finds | Whales
A mass stranding and death of 55 whales on the Isle of Lewis in 2023 was due to the mammals’ loyalty to their herds, a report has concluded.
It was thought that the unusually large incident, which occurred at Tolsta’s Tràigh Mhòr beach, could have been caused by trauma, disease, or acoustic disturbance from military or industrial noise.
But, reportCiting a “combination of biological, behavioral and environmental factors”, the Scottish government’s Marine Directorate suggested long-finned pilot whales are a species. highly social speciesShe died because the group was pursuing a woman who was going through a difficult labor.
The chief scientist of the study, Dr. Andrew Brownlow Plan to Land Scottish Marine Animals (Smass) said: “The Tolsta incident is a reminder that mass strandings are rarely the result of a single cause, but rather occur at the intersection of individual physiology, group social behavior and external marine environmental conditions.
“Understanding how these factors interact is crucial if we want to improve our capacity to predict, interpret and, if possible, mitigate the impacts of a changing ocean.”
The report stated that the whales were in good health but had moved into shallow water following a “single threatened female”. Post-mortem examination showed that the female whale had experienced a long and difficult birth, which triggered the pod’s fatal movement into the shallow bay.
The whales were seen wandering near the shore before stranding. This type of behavior, in which a pod comes together to support a sick or injured member, may be crucial to survival in the open sea as a means of defense against predators, Brownlow said.
“If one member of the pod were in danger, the well-documented social cohesion of this species would lead others to assemble closely in a protective response,” he said.
“In this example, this behavior appears to have attracted the group to shallow, sandy bathymetry [the water depths] “The gently sloping seabed and fine suspended sediments in the bay may have created an ‘acoustic trap’ that weakened echolocation signals and reduced the group’s ability to return safely to deeper waters.”
Whales that could not return to the water had to be euthanized on shore to avoid further distress.
The scientists’ findings are particularly vital to efforts to understand why 77 more animals of the same species – one of the largest ever recorded off the British coast – were stranded on Sanday beach in Orkney almost a year later. This incident is still being investigated by Smass.
The organisation’s long-term monitoring data shows the scale and frequency of mass strandings of whales and dolphins in Scottish waters has increased by up to 300% in the last 30 years. Other latest reports The findings regarding pilot whale strandings support Smass’s conclusion that human-made sound is not a factor in strandings.
But 10 sperm whales washed ashore January and February in places including Cornwall, Denmark and Germany. The unusual stranding of large toothed whales has raised concerns among scientists that military or industrial noise pollution could drive deep-diving whales into shallow waters where they cannot feed.
Additional reporting: Jeroen Hoekendijk
