A super rare Greenland shark that stranded on a beach in Cornwall has been confirmed to have had an infection of the brain, believed to be the first recorded disease-related death of this elusive species.
The juvenile female shark, potentially around 100 years old and measuring 3.96m long, stranded just outside Newlyn Harbour temporarily on Sunday 13th March and was later recovered from the sea nearby on Tuesday 15th March. A post-mortem was conducted the next day by the Cornwall Marine Pathology Team, part of ZSL’s Cetacean Stranding Investigate Programme (CSIP).
Pathologists found evidence of meningitis in the juvenile female and believe this explains why the shark was out of her natural deep-water habitat, and the cause of her stranding - and eventual death.
James Barnett, pathologist from the Cornwall Marine Pathology Team said: “During the post-mortem examination, the brain did look slightly discoloured and congested and the fluid around the brain was cloudy, raising the possibility of infection. This was then confirmed on microscopic examination of the brain (histopathology). A species of Pasteurella, a bacteria, was isolated from the fluid and this may well have been the cause of the meningitis.
“The shark’s body was in poor condition and there were signs of haemorrhage within the soft tissue around the pectoral fins which, coupled with the silt found in her stomach, suggested she may well have live stranded. As far as we’re aware, this is one of the first post-mortem examinations here in the UK of a Greenland shark and the first account of meningitis in this species.”
Greenland sharks (Somniosus microcephalus) live in the deep waters of the Arctic and North Atlantic oceans up to 8,684 feet (2,647 meters) below the surface. They are still a very mysterious species with some individuals described as having the potential to live to over 400 years old.
Rob Deaville, ZSL’s Cetacean Stranding Investigation Programme (CSIP) project lead said: “This unfortunate and extraordinary stranding has allowed us to get an insight into the life and death of a species we know little about. Discovering that this shark had meningitis is likely a world’s first, but the significance of this in terms of any wider stressors is unknown. Ultimately, like most marine life, deep sea species such as Greenland sharks may also be impacted by human pressures on the ocean but there is not enough evidence at this stage to make any connections.
“Huge thanks are owed to the volunteers of Cornwall Wildlife Trust Marine Strandings Network and all those who spotted and brought the body to shore. This was an exceptional collaborative effort by all involved and was a unique opportunity to learn more about the life of this cryptic and endangered deep-water shark.”
A research paper looking more deeply at the team’s post-mortem investigation of the Greenland shark will be published in due course.
CSIP coordinates the investigation of all cetaceans, marine turtles and basking sharks that strand around the UK coastline. Since the launch of the CSIP in 1990, data on over 17,000 stranded cetaceans have been recorded in the UK and nearly 4,500 necropsies have been carried out, producing one of the world’s largest research datasets on strandings and causes of mortality. CSIP are reliant on the UK public to report strandings and urge anyone who spots a stranding to call the national hotline number on 0800 652 0333.