First Basking sharks of the season seen off UK coasts.

29/06/2007 00:00:00 Divers – we need your basking shark records

April 2007. One of the most unforgettable sights in the summer months, off the western coasts of the United Kingdom and Ireland is that of the slow majesty of a group of basking sharks feeding on the surface of a still sea - their noses, dorsal fins and tails breaking the surface of the water.

The first three sightings reports for 2007, (22nd March, in Cardigan Bay, West Wales; 24th March, near Douglas on the Isle of Man; and 7th April, near Falmouth in Cornwall). Basking shark numbers will increase dramatically over the next few months, and there is every chance you might spot one from a beach, cliff top, boat or surfboard. The Marine Conservation Society (MCS) is appealing to everyone to report their sightings of these wonderful and endangered creatures, the largest wild animal to regularly visit the UK. Despite being a protected species, these fabulous animals still suffer from a variety of threats such as harassment by inquisitive water users, collisions with boats, and entanglement in fishing gear and marine litter. Such threats continue to take a toll on these animals, but we need to know more to be able to take action and give them the full protection they deserve.

Cornwall Wildlife Trust, together with other partners working towards conserving basking sharks, believe that many sharks die as a result of becoming entangled in fishing net but we do not have the evidence to back this theory up as many go unseen and unrecorded. We are therefore asking for your help to tell us what you see while diving.

Basking sharks can grow up to 11 metres long and weigh in at 7 tonnes, about the same size and weight as a double-decker bus. They are the second largest fish in the world - the largest being the whale shark - and like their bigger cousin, they are filter feeders. They filter out tiny zooplankton using modified gill rakers as they swim with their enormous mouths wide open, processing up to 6,000 litres of sea water, the equivalent to an Olympic sized swimming pool, every hour. When these sharks find a concentration of zooplankton they cruise back and forth - sometimes in groups of over a hundred.

Ruth Williams, Marine Conservation Officer for the Trust said, ‘Basking sharks appear off the coast of Cornwall in April with the highest numbers appearing in May and June. What determines these sharks behaviour is not fully understood. We know that they, like other sharks, use an acute sense of smell and detection of electrical activity to track their tiny prey. But many aspects of their life remain a mystery and they continue to be a subject for ongoing survey and research.’ In one case recently, a group of divers were able to free a female shark that was caught in a net on the seabed - not an easy task and one that should only be attempted by experts, but a happy ending for that particular shark.

Ruth continued, ‘Divers also have the same responsibilities as other water users to respect these wonderful creatures so we urge you to abide by the Basking Shark Code of Conduct. Slow down or ideally cut your engines, don’t get too close, and don’t chase or harass them. Please remember that it is illegal to kill, injure or recklessly disturb basking sharks and other protected marine wildlife. Though these sharks do not normally present a threat to humans they can do a lot of unintentional damage with their tails so we advise people not to swim close to them if possible.’

You can report your basking shark records by either phoning Joana or Ruth on 01872 273939 ext 207 or via our website at www.cornwallwildlifetrust.org.uk/nature/marine/record

Please report any incidences of entangled sharks to Cornwall Wildlife Trust's Marine Strandings hotline number on 0845 201 2626.

Courtesy of the Marine Conservation Society and Cornwall Wildlife Trust