Shark Trust president Richard Peirce: 'Conditions here mirror those in parts of South Africa, Australia and northern California'
By Stephanie Darrall
British waters are an ideal hunting ground for great white sharks, who are already 'occasional vagrant visitors', claims a shark expert.
President of the Shark Trust Richard Peirce said that it is only a matter of time until his theory that the predators visit British shores is verified.
Mr Peirce believes he almost proved the presence of a great white in the UK with a photograph of a shark caught off the north-east coast of Scotland.
He said: 'I sent the photo to some of the world's leading experts but as soon as they heard it was caught off Scotland they started looking at what else it could be.'
'The real surprise is that we don't have an established white shark population, because the conditions here mirror those in parts of South Africa, Australia and northern California.
'The normal range of water temperature for great whites is between 14C and 20C which fits with British water in the summer.'
The shark expert has investigated more than 80 reported sightings of great whites in British waters over the last 14 years but only seven were found to be credible.
Fishermen in Cornwall have reported great whites sticking their heads out of the water, known as 'spy-hopping', and fishermen on three different boats described a sighting of a great white within three weeks of one another.
Mr Peirce said: 'The reason the evidence is so compelling is that it's from independent witnesses who do not know each other on different boats.
'The problem is these things happen in a flash. Unless the shark jumps right out of the water or is caught, all we'll see is a dorsal fin sticking out the water.
'The closest capture of a great white was off La Rochelle (in western France) about 200 nautical miles from UK shores which is no distance to them.'
There have been sightings of other sharks in British waters over the summer.
Earlier this month fisherman Jim Millar spotted a 15ft thresher shark off Dartmouth in Devon, where they are very rarely seen.
Another fisherman caught a 21 stone porbeagle shark off the coast of Donegal, Republic of Ireland, last month.
There have also been two separate sightings of what was believed to have been an oceanic whitetip shark, a species also known to attack humans, in St Ives, Cornwall, in June.
Mr Peirce believes it is only a matter of time before proof is found that the species at the top of the marine food chain, the great white shark - Carcharodon carcharias - is occasionally present in British waters.
He said: 'Great whites are highly nomadic in movement around the north Atlantic so it's reasonable to say there's a good chance they may stray into British waters.
'I do suspect we do get the occasional vagrant visitor.'
Global warming may have driven the sharks' prey further north, added Mr Peirce, which could further entice the great white to British shores.
He said: 'The water temperatures around Britain are well within the great white's tolerance range. So in theory there's no reason they shouldn't be here already without global warming.
'But what may be happening is that it may affect the distribution of shark's prey - meaning they may follow that.'
However Dr Russell Wynn, co-ordinator of the SeaWatch SW project and a senior marine scientist at the National Oceanography Centre in Southampton, said the odds of a great white being found in British waters were extremely low as the creatures are very rare in the northeast Atlantic.
The SeaWatch SW survey team has spent more than 5,000 hours scanning the seas off southwest England in the past five years but the only predatory sharks seen have been single blues and threshers.
Habitat: A map showing the global distribution of the Great White Shark
'The only large shark the public are likely to see is the harmless plankton-feeding basking shark, which can grow to over 10m long and is occasionally seen leaping out of the water,' he said.
But Dr Wynn accepted there was a small chance of a great white sighting off the British coast.
'It's certainly not impossible that a great white could be seen or caught in British waters one day, as we know they occur off southwest Europe in very low numbers.'
Spotted: In recent months both thresher (left) and porbeagle sharks have been seen around the British Isles
But despite the recent sightings, the opportunity of seeing sharks is decreasing year on year.
A study by Dalhousie University in Nova Scotia, Canada, concluded that the North Atlantic shark population had declined by more than 50 per cent between 1986 and 2000 due to overfishing.
Mr Peirce said: 'Unless we do something about shark mortality in the Atlantic we won't be having this conversation in 50 years time.'
The Great White: An expert claims these predators will soon be spotted in British waters