Warning over swimming with dolphins
Holidaymakers have been warned not to swim with dolphins off the coast of Cornwall because of fears they are carrying a potentially harmful bacteria.
Scientists have warned that the population of bottlenose dolphins living around the South West coastline could die out because of the spread of the bacteria, which they believe is linked to chemical pollution.
Cornwall Wildlife Trust's Marine Strandings Network (MSN) said there could be a link between higher than usual instances of Brucella ceti found in dead animals washed ashore and polychlorinated biphenyls (PCBs), toxic chemicals added to paints, cement and other industrial fluids until it was banned 10 years ago.
A spokeswoman for the trust said that the risk to people was "very small indeed", but added: "Nevertheless, the AHVLA (Animal Health and Veterinary Laboratories Agency) recommends that people don't swim with dolphins or touch any bodies they find on the beach, just in case."
Scientists from the AHVLA in Truro, working with MSN, analysed samples taken from dolphins found dead on beaches in Cornwall over the last six years. They found more than half were carrying Brucella, something rarely found in bottlenose dolphins or any other species off Cornwall.
No other cases were found in 15 bottlenose dolphins found dead in the rest of England and Wales between 1989 and 2008, and only one found out of 36 dolphins examined in Scotland during the same period. The scientists also found the levels of bacteria in the Cornwall dolphins were "much higher" than in other species they had examined. It is carried by other water-born mammals including whales and seals. And scientists fear that pollution is to blame.
PCBs were banned under the UN Stockholm Convention in 2001 but they can still be found in ocean waters. They get into the fish the dolphins eat and are readily absorbed into fat, including dolphin blubber.
The wildlife trust said high exposure to PCBs may increase susceptibility of the bottlenose dolphins to infections, including Brucella ceti, and have also been linked to fertility and reproductive problems in the intelligent mammals.
Jan Loveridge, MSN co-ordinator, said: "Strandings and sightings data suggest that UK bottlenose dolphin populations, including ours in Cornwall, have declined markedly from historic levels and the loss of any individuals from such a small population will have a strong impact on its ability to survive.
"The bottlenoses are such a local icon; they're part of Cornwall's heritage and one of the reasons that people visit the county. It would be a tragedy if we lost those precious moments when we see them leap and flip in the air and I'd hate to think that our children and grandchildren might be denied that pleasure. We need to keep monitoring how they're doing, and do whatever we can to protect them."