Nature Features

Last year only 26 sightings of basking sharks were recorded off Cornwall's coast. This year a team of 40 volunteers working with the Cornwall Wildlife Trust have provisionally recorded 972.

The volunteers have also recorded sharks breaching the surface of the water, which is rare.

Basking shark by Colin Speedie

Mike Langshaw, who co-ordinates the volunteers, says: "It is rare to see them breech. At one time there was a lot of doubt as to whether they did it or not.

"A lot of people did not believe they breeched but there is now no doubt they do. We have no idea why they do it. It could be associated with courtship behaviour.

"But we have seen single animals just jumping out of the water. Some believe they are trying to get rid of parasites but we just don't know."

Experts from the Cornwall Wildlife Trust believe recent hot weather is the reason for the large number of basking sharks in our waters. Sunshine boosts the levels of their favourite food - zooplankton.

Two years ago off Sennen there were sightings of groups of between 3-400 basking sharks.

Basking Shark by Ollie Chambers.

Mike Langshaw says: "We're not seeing groups of that size. At the beginning of June were were seeing groups of between 20-30."

"They are all age ranges and measure up to 6-7 metres long."

Although basking sharks can measure up to 12 metres long and weigh up to 7 tonnes they are harmless to humans, and are known as "gentle giants".

The fin of the endangered basking shark.

The basking shark is an internationally recognised endangered species with legal protection. It is hunted for its highly valued enormous fins, which are a delicacy in the Far East, and hunting remains the single biggest threat to its future.

Little is known about the basking shark, which makes effective conservation very difficult.

Send us your pictures of basking sharks. Email us at cornwall@bbc.co.uk. Remember to following the basking shark code of conduct at all times.