So many people think they have to travel to the other side of the world to see fantastic, exotic species

Colin Speedie Shark Trust

The human psyche may be conditioned to send a shiver down the spine when seeing a large shark but the gargantuan beasts that patrol British shores every summer are totally benign.

Armed with an underwater camera, I set out from Falmouth to see for myself these somewhat mythical beasts.

It seems extraordinary that such massive fish, known to grow up to 13 metres or 40 feet, can be found right on our doorstep yet so little is known about them - like so much of our undersea heritage.

Photo identification

For the past three years, Colin Speedie, chairman of the Shark Trust, has been trying to unravel some of the mysteries of the basking shark (Cetorhinus maximus).

John McIntyre saw eight sharks in two days

He won the backing of both the World Wildlife Fund (WWF) and the Wildlife Trust for a research programme which uses photo identification to identify individual animals.

He has now built up an impressive catalogue of photographs to help study the creatures' behaviour patterns, especially those sharks that are sighted in the same locations every year.

Most have unique markings on their dorsal fins, either naturally occurring or caused by accidents with boat propellers.

To the casual observer, basking sharks appear almost prehistoric looking, with mouths that gape like giant vacuum cleaners.

Beautiful creatures

But as Colin Speedie says: "They are beautiful creatures.

"So many people think they have to travel to the other side of the world to see fantastic, exotic species.

"But you don't, they're right around our shores."

Colin Speedie: Unravelling the mysteries of the basking shark

When the southwesterlies finally died down and the seas off the Lizard in Cornwall had calmed, I spent just a few hours scouring the horizon for those all important tell-tale dorsal fins.

We finally caught up with one large shark and it was not long before three others appeared.

It is an awesome spectacle getting within a matter of a few metres of a five to six-metre basker when its cavernous mouth is at full stretch, siphoning some of the tiniest critters in the ocean by the million with every gulp.

Over two days, we saw eight different sharks.

Endangered species

Many environmental organisations list the basking shark as an endangered species.

We know little about population sizes and therefore just how badly damaged they have been by hunting in some parts of the world.

To the casual observer, basking sharks appear almost prehistoric looking, with mouths that gape like giant vacuum cleaners

John McIntyre

Their enormous dorsal fins are sold for small fortunes as trophies or for shark fin soup. Their liver oil is also especially sought after.

Shark conservation is slowly but surely starting to win over hearts and minds, whether in favour of the sharp-toothed variety or the harmless plankton eaters.

Colin Speedie's research for the European Basking Shark Project is still in its early days but his initial hunches about where they live now seem to have scientific credence.

Local populations

More and more, he is seeing the same sharks in the same locations.

Most sharks have unique markings on their fins

This coupled with historical detail about hunting and fishery, he believes, suggests a strong possibility that baskers are residents of British shores rather than summer visitors.

One possibility is that they simply disappear from the shallows, heading off into deeper water in winter.

"We are actually seeing the same sharks year in year out which makes me think we're looking at local populations.

"If that's the case they're extremely vulnerable to hunting in an aggressive nature," said Mr Speedie.

Basking sharks of course have a degree of protection in Britain.

While many more years' research is needed to corroborate these theories, Mr Speedie is hopeful that marine parks can be established where sharks are most regularly sighted.

Eco-tourism could in turn, he says, generate much greater interest in sharks and help create a better understanding of these native primeval giants.