Rare dolphin found at Porthtowan

20th December 2006

The body of a bottlenose dolphin, a rare animal in Cornwall, was retrieved by volunteers yesterday from a cove at Porthtowan on the north coast.  The male dolphin was reported to the Marine Strandings Network of the Cornwall Wildlife Trust by one of its new volunteers, Dominique Strover, who lives nearby.

Measuring just under 3 metres, the male dolphin presented a real challenge for the Strandings Volunteers as it weighed around 200kg.  As Gary Hawkins, one of the volunteers explained, “It was found in a small cove to the west of Porthtowan and it would have been really difficult to carry the dolphin off the beach, even though there were six of us to help lift it.  Luckily, a Reserves Officer from the Cornwall Wildlife Trust was able to provide a 4x4 vehicle and trailer to enable us to get around the rocks at low tide and remove the dolphin from the beach.  It was then taken to the Veterinary Laboratories Agency at Polwhele for autopsy.”

Stranded Bottlenosed dolphin with volunteers photograph by Jan Loverage

Ruth Williams, Marine Conservation Officer of the Trust said, “We were very keen to secure the dolphin for post mortem examination.  The resident population of bottlenose dolphins around Cornwall is now so small that any loss, for whatever reason, is of vital importance.  We need to get as much information from the animal as possible to support our work for the long-term conservation of this well-loved species.  I examined the animal on the beach but couldn’t find any obvious external injuries to indicate cause of death, although it was covered in rake, or tooth, marks from other bottlenose dolphins, which can often be a sign of aggression.  It didn’t appear to have been caught in nets, but a post mortem will hopefully tell us why it died.”

The Marine Strandings Network has recorded only six dead bottlenose dolphins in the last five years.  This may seem like good news but the reason for the low number is more likely to be that there are so few left and there are real concerns that their numbers in Cornwall are dropping too low for the population to carry on.

Local cetacean scientist, Nick Tregenza commented, “This species is the one so many people have seen and love.  We estimate that there are perhaps only between 12 and 20 animals of this species in the inshore waters of Cornwall and the south-west. 

“They were lost from the south west in the 1960s, probably as a result of pesticide pollution, and they then re-colonised Cornish waters in 1991.  There has been great progress on the pesticide issue and we hoped this inshore group would multiply back up to the numbers of old, but actually it has dwindled slowly for several years.  Bottlenose dolphins are remarkable animals with a huge brain and are one of the tiny handfuls of species that are intelligent enough to recognise themselves in a mirror.  They live for up to 40 years, possibly more, and the group around Cornwall could not sustain a death rate of even one animal per year, long term.  The loss of an adult is particularly serious, and the biggest single risk to them is probably inshore gill netting.  In their very precarious state it is vital we continue to monitor their numbers and movements and try to identify all causes of death.”

This dolphin brings the number of dead cetaceans recorded by the Network in 2006 to 170, a 70% increase on 2005 and, as the year draws to an end, the worst time for dolphin deaths is about to begin so the figure is expected to rise. The public is urged to continue to report dead stranded dolphins, seals and other marine life to the Marine Strandings Network’s 24-hour Hotline on 0845 201 2626.  To find out more about the work of the volunteers visit www.cwtstrandings.org or www.cornwallwildlifetrust.org.uk.