'Fishing to blame' as dolphin deaths soar

2:05am Monday 7th July 2008

Industrial fishing is largely to blame for soaring numbers of dead whales, dolphins and porpoises being washed up on Cornish beaches, say scientists.

Strandings of the marine mammals have risen sharply in number since the expansion of large-scale fisheries, a study found.

Researchers analysed records of cetacean strandings around Cornwall's north and south coasts and the Isles of Scilly from 1911 to 2006.

A marked increase was seen after the early Eighties, mostly involving common dolphins and harbour porpoises.

Fewer than 50 strandings a year occurred in the Eighties, but since 2000 the numbers have ranged from 100 to 250 per year.

Cornwall's south coast has experienced the largest number of strandings, especially around Mount's Bay, near Penzance, and two of the county's most popular beaches, Looe Bay and Whitsand Bay.

In total, the team from the University of Exeter and Cornwall Wildlife Trust looked at 2,257 cases of cetaceans found dead on beaches, 862 of which were common dolphins.

Since 1990, at least 61 per cent of the incidents were confirmed as being caused by fishing, with the animals accidentally being caught up in trawlers' nets and drowned as "bycatch".

The seas around Cornwall are now one of the major hunting grounds for large scale fishing fleets from European Union countries.

The new findings, published in the journal Biodiversity and Conservation, come only a month after the mysterious death of 26 dolphins found stranded in a shallow river estuary near Falmouth.

Experts are still puzzling over the mass death of so many apparently healthy animals.

Theories include pursuit by a predator, such as a killer whale, and disruption of the creatures' echo location sense by military sonar.

Researcher Dr Brendan Godley, from the University of Exeter's Cornwall Campus, said: "Many people were shocked by the recent graphic images of the mass dolphin strandings in Cornwall, the cause of which is still a matter of conjecture.

"We feel that the important message is that strandings have increased in recent years and that the majority are attributable to bycatch in marine fisheries.

"This is clearly a major issue that needs to be addressed by the Government and the fishing industry in addition to conservation organisations."

Another reason for increasing numbers of stranded whales and dolphins could be climate change, the scientists acknowledge.

Warmer waters may be attracting more cetaceans from southerly regions to the seas around Cornwall.

Joana Doyle, of the Cornwall Wildlife Trust, called for the establishment of a network of marine conservation zones and an EU wide ban on pair-trawling for sea-bass.

Pair trawling involves two vessels working together dragging a huge net between them.

Greenpeace says UK and French pair trawling fleets alone could be killing more than 2,000 dolphins a year.

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