Schottland was faced with several unusual stranding clusters during the last month. Now, post-mortem reports point to noise-mediated decompression sickness. To investigate possible causes, the Ministry of Defence was asked for their naval sonar data to find possible causes.
The main evidence comes from two Sowerby’s beaked whales stranded only one day from each other on the Lothian coast. Both sub-adult males were in reasonable body condition with no sign of underlying diseases, entanglement or boat strikes. An immediate cause of death was, therefore, more likely. Concordantly, they both had an unusually high number and distribution of gas bubbles in their tissue, suggesting decompression sickness. Since the deep-diving species is unusual in the area and highly sensitive to underwater noise, the investigators from the Scottish Marine Animal Strandings Scheme (SMASS) assume that the whales might have been frightened by the sonar waves and surfaced too quickly, leading to decompression sickness as immediate cause of the stranding.
Additionally, three subadult northern bottlenose whales were found in the Western Isles and in the Clyde sea lochs. Similarly to the previous cases, no evidence of disease, entanglement or ship strikes could be found. However, the carcasses were reasonably decomposed which limited the diagnostic range.
SMASS explains that “given this was an obvious cluster of unusual cases, we are keen to gain what information we could.” Thus, the Ministry of Defence was asked whether their recent Nato war games event around the coast of Sutherland might have been responsible for the cluster of events. Underwater military activity has previously been shown to have been the cause of Scotland largest stranding event in 2011. Since then, the Ministry of Defence says that “the Navy does all it can to ensure sonar is not damaging marine life.”
The full article can be found here: https://www.northern-times.co.uk/news/ministry-of-defence-asked-for-naval-sonar-data-after-whales-stranded-216492/
Comentarios