Divers have stumbled across possible evidence of global warming off the Sussex coast.

They discovered a small shoal of 15 grey triggerfish, three miles south of Worthing.

Paul Parsons, 37, from Sompting, near Worthing, said: "They are living on the underwater chalk cliff that lies offshore.

"These creatures are unusual to this area and little is known about them. Any sighting of them is usually important.

"Basically, these fish are thought to travel on the Gulf Stream to UK shores and there are theories about whether they stay here over winter or group up before heading back to the Atlantic.

"Over the last few years, they have become more frequent but not enough to be a regular sighting so it is very unusual, especially for this time of year."

He believes it might be a sign that the sea is becoming warmer, although one other theory is that there are more divers exploring the seabed so the chances of finding rare species have increased.

Earlier this year, Mr Parsons found and photographed hundreds of potatoes on the seabed around the base of the Palace Pier in Brighton.

There were fears that the rotting potatoes might float to the surface and wash up on the beach during the holiday season.