Scientists from the Zoological Society of London have examined a 12.44-meter-long (41-foot) sperm whale that was recovered from the Thames Estuary having stranded in Swale, Kent. Swift investigations on the cetacean’s carcass aimed to uncover the cause of death and assess how this usually deep-sea dwelling creature found itself in shallow UK waters.
Sperm whales are the largest of the toothed whales, a group that includes beaked whales, dolphins, and porpoises. With a roaming range that spans the globe, sperm whales migrate seasonally to breed and feed. Females will stick with their calves to provide nursing and protection for over a decade and will even cooperate with other females during this time, but males, known as bulls, roam solo outside of the mating season.
The young male sperm whale was first spotted off the coast of Whitstable, Kent, three days before it was recovered from the water. The sighting drew much attention from locals amid fears it would get trapped in the shallow waters and eventually beach on the mudflats at low tide. When the whale eventually passed, it was recovered from the water and taken to Peel Ports London Medway for investigation. The contents of its many stomachs, of which sperm whales have four, were checked with fears the growing crisis of ocean plastics could be to blame, but researchers from the Cetacean Strandings Investigation Program (CSIP) at ZSL instead found them to be completely empty.
Squid are the favorite food of sperm whales and recent feeding is usually indicated by the presence of squid beaks. This unfortunate whale, however, had none in any of its stomachs, indicating it would have been severely malnourished. Starvation as the cause of death was further supported by bile stains throughout much of the intestinal tract, suggesting the whale had likely been in the southern North Sea for some time. Working through the night, specialists dissected the carcass at Peel Ports London Medway, sending off tissues for analysis to try and further understand what brought this young whale to UK shores.
In a statement to ZSL, Rob Deaville, CSIP project manager, said: “The findings are consistent with live stranding of an out of habitat individual. Sperm whales are normally found resident in much deeper waters and the southern North Sea can be considered an abnormal habitat for the species as they are unable to feed there.”
This isn’t the first time a sperm whale has sprung up in southeast England, with a similar case happening in Kent in February 2014. In January of 2019, “Benny the Beluga” was spotted several times in the Thames Estuary. Despite being alone, the individual appeared to be healthy and is believed to have returned to the open ocean later the same month.
While an unfortunate fate for this young whale, the information gathered from the CSIP’s investigations will help shed light on the life of this individual, the condition of our oceans, and inform future conservation efforts. If you think you might have sighted a cetacean in UK waters, you can reach out to the CSIP here.