Wildlife groups have made fresh calls for a ban on pair trawling after more than 20 dead dolphins washed up on Westcountry beaches.
A total of 21 dolphin carcasses have been found on Cornwall's beaches, and two in Devon, in the past five days.
Wildlife groups say that number is certain to rise over the next few weeks, with French and Scottish pair trawlers moving up the Channel as the annual bass fishing season gets under way. Joanna Doyle, marine conservation officer for the Cornwall Wildlife Trust, said: "Yet again, the slaughter of dolphins has begun."
Many of the dolphins bear scars which environmental groups claim come from fishing nets.
The Cornwall Wildlife Trust said its 120 volunteers have struggled to keep up with the sheer number of carcasses washed on to the beaches.
Maddi Precious, who covers the special 24-hour strandings hotline for the trust, said: "The phone has not stopped ringing. Distressed members of the public keep calling to tell us of yet more bodies and we send out our dedicated volunteers right away. It's been hard to keep up."
The Devon Wildlife Trust say two dead dolphins were found near Plymouth, and the Cornwall Wildlife Trust said carcasses have been found all along the south coast of Cornwall, including at the Roseland Peninsula and St Austell Bay.
Post-mortem examinations will be carried out on some of the dolphins to officially determine what caused their deaths, but many believe the results are a foregone conclusion.
It was hoped a ban on using pair trawler techniques, which are widely blamed for dolphin deaths, within 12 miles of the shore would spare the animals but it does not appear to have curbed the problem.
Joanna Doyle said it was apparent a recent Government ban on pair trawlers fishing within the 12-mile shore limit is not working. While most of the dolphins have so far been found on Cornish beaches, Lindy Hingley, founder of Brixham Sea Watch, says it is only a matter of time before Devon sees a big rise in the problem. She said: "The pair trawling fleets always start the season off the coast of Cornwall and then move our way, which is a grim prospect. It is an absolute disgrace this has been allowed to carry on and it needs to stop. I'm surprised there are any dolphins left to wash up on the beach."
Greenpeace have also claimed the number of dolphins washed up on beaches represents only 10 per cent of those actually killed by fishing nets, as most of the carcasses sink.
Jim Portus, chief executive of the South Western Fish Producers Association, said: "The fishermen responsible for this unintentional by-catch of dolphins are highly likely to be from outside of the UK.
"It goes to show that this kind of disruption won’t be stopped until there is international agreement. So far this has not happened, and that is very frustrating for everyone concerned with the welfare of dolphins."