Rise in sightings of exotic sea life enchants Devon and Cornwall

Seeing exotic marine life no longer requires journeys to far-flung corners of the globe.

Seeing exotic marine life no longer requires journeys to far-flung corners of the globe. Instead, head for Cornwall and Devon where sightings of sea creatures more associated with tropical or Mediterranean waters – and birds of the Antarctic and Pacific Latin America – are creating a buzz of excitement among naturalists.

The evidence seems to contradict fears that the Gulf Stream and the North Atlantic Drift, which keep Britain's climate warm with water from the Caribbean, may be slowing down due to melting polar ice caps caused by global warming.

And Stella Turk, of the Cornwall Wildlife Trust, believes a rise in sea temperatures may be benefiting wildlife spotters. "It appears the sea is becoming generally warmer and it could be that such creatures are staying close to Britain throughout the year. An unusually wide range has already been reported this summer and it's still only mid-July – there could be many more surprises over the coming weeks."

One spectacular result has been the sight of hundreds of root-mouthed jellyfish, Rhizo-stoma octopus, up to 3ft across and with thousands of tiny mouths. Each mouth is armed with sting cells to paralyse plankton food.

A more widespread occurrence has been of by-the-wind sailors, Velella velella. This jellyfish-like hydrozoa is not a single creature but a colony of tiny polyps suspended from a sail-like floating comb.

In Newquay, the Blue Reef Aquarium has become home to the fourth slipper lobster, Scyllarus arctus, to be found in local waters in two years. Only 13 of these small creatures from the Mediterranean had been recorded over the previous 250 years.

The aquarium is also caring for two loggerhead turtles, which drifted to Britain on currents possibly after suffering flipper damage at their mid-ocean feeding area. It is hoped they will be fit enough to be returned to the wild later this month.But the aquarium manager, Richard Smith, stressed that they would not be put back into the sea locally as the water temperature is still too low for such cold-blooded animals. The likely result is a flight to the Canary Islands for a warmer re-launch. Three other loggerheads that reached south-western waters did not survive. Two leatherbacks, also found on the Cornish coast, are thought to have followed rhizostoma jellyfish, on which they feed.

Sunfish, Mola mola, which are large, flat and disc-like, have been spotted increasingly in recent summers but Ms Turk said this year's sightings began earlier, in May. Another surprise is a report of a 6ft bluefin tuna, Thunnus thynnus.

Yesterday, a school of up to 40 basking shark was spotted a mile off Perranporth, north Cornwall. A pilot whale was also seen with them. A spokesman for Falmouth Coastguard said: "The sharks are huge – they go up to 30ft. When the water warms up we do get basking sharks here, but it is unusual to get so many."

Other big marine mammal happenings have included a sperm whale and its calf off Portherras Cove, north of Land's End, last month, while a Sowerby's beaked whale stranded on Praa Sands also attracted attention.

The Channel region's main whale concentrations are noted from ferries sailing between Portsmouth and Bilbao, in Spain. On a recent crossing, experts logged a fin, two sperm, two Cuvier's beaked, 34 pilot and five minke whales – as well as 508 striped, 49 common and four bottlenose dolphins.

Unusual birds, thousands of miles from their typical haunts, are also appearing. An elegant tern, reported last Monday at Dawlish Warren, near Exmouth, was a first for Britain. Normally this species occurs in Californian waters and along the Pacific coasts of Central and South America.

Boatloads of birdwatchers are being ferried almost daily up to eight miles south of the Isles of Scilly to see Wilson's petrels – small seabirds, a little bigger than sparrows, which have flown more than 8,000 miles from Antarctica.

Fascinating foreigners drawn to the Cornish Riviera

*Two sperm whales were recently spotted in the English Channel from a ferry sailing between Portsmouth and Bilbao in northern Spain. Adult males reach lengths of up to 60 feet (18m) and weigh up to 45 tons (41,000 kg).

*Newquay's Blue Reef Aquarium is caring for two loggerhead turtles which probably drifted to Britain after damaging their flippers in mid-ocean. They may have to be flown to the Canaries to be released.

*Sun fish, Mola mola, are normally seen in the coastal regions of North America. They have been spotted off south-west England more regularly over recent summers, but this year they arrived earlier.