An expert has sought to allay the fears of fishermen after they reported seeing a shark off the County Durham coast.
It is possible the shark could be a Mako
A number of anglers have reported seeing fins in the water off Seaham, with one even heading back to shore because of his concerns.
It is thought it could be a Mako or Porbeagle shark.
Shark conservationist Richard Peirce said there were no reports of attacks by either species in waters off the British coast.
Fisherman Norman Conn, who is secretary of the Seaham Environmental Association, said: "There have been at least four sightings that I know of.
"I think given the weather throughout July - the calm and clean conditions - has given the boats an opportunity to get out more often inevitably resulting in more sightings throughout July.
"The sightings have been within about 500 metres of Seaham North Pier. Also the longest sighting eight miles out over a wreck - a group of anglers fishing saw this 18 ins fin come towards them, circle the boat and disappear. The lads obviously got a bit of a shock."
Mr Peirce said it was possible it was a Mako shark but also agreed it was likely to be a Porbeagle.
He said: "If you look at Mako records since records began, it works out to one Mako attack in the entire world about every 50 years. So the chances of being run over by a runaway pram are probably slightly greater.
"So I just think we need to get this fear thing into perspective.
"They have been on record attacking man but the chances are so remote it's infinitesimal. They also are a British resident and have been for tens of thousands of years and there isn't a Mako attack recorded around Britain at all."