© Wessex News Agency/Clare RileyConcern: A dolphin found at Smeaton's Pier in St Ives, Cornwall is the tenth discovered dead along West Coast beaches in as many days, prompting fears over what could be killing them.
Pollution, trawler nets, inclement weather and jet skiers have all been cited as likely causes for the demise of these marine animals.
Clare Riley was among those who found the latest dead dolphin on the beach near Smeaton's Pier in St Ives, Cornwall.
'It was sad to see - I've been in Cornwall for six years waiting and hoping to see dolphins and I was finally rewarded two weeks ago with an awesome display of a pod playing and surfing the waves at Gwithian,' she said.
Another resident, Tony Mason, said: 'I saw them at Gwithian last Sunday, swimming around jet skiers. To then find that one dead was so sad. Such a beautiful creature.'
Between January and March last year, 61 dolphins, porpoises and whales were found dead around Cornwall's coast, the steepest rise in the death toll since 2006, according to the Cornwall Wildlife Trust.
They said previous post-mortem tests showed creatures washed up on the shores had died from a number of causes, including pollution, illnesses, natural causes and after being caught in fishing nets.
Comment: Last month in two separate incidents, thousands of dead fish were discovered on Pentewan and Marazion beaches in Cornwall.