The Wildlife Trusts' Basking Shark Project

This gentle giant is the largest fish to be found in the coastal waters of the British Isles. Measuring anything up to 12 metres long, and weighing up to 7 tonnes, it feeds on animal plankton, filtering 1,000 to 2,000 cubic metres of seawater per hour to extract its tiny prey. During the summer months, it favours Cornish, Devon, Manx, Irish and Scottish waters as its regular feeding grounds. The basking shark is an internationally recognised endangered species with legal protection. Its main attraction now lies in 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. Without accurate population numbers it is difficult to tell whether populations are in recovery or decline. Without a clear idea about their most favoured feeding sites, it is difficult to know what conservation strategies will be the most effective, or which sites need further protection.

Over the last 10 years, Colin Speedie and his team of dedicated researchers have carried out The Wildlife Trusts Basking Shark Survey, sailing the entire length of the west coast of the UK, from the southwest to the Hebrides, in Scotland. Crewed by changing teams of volunteers, the survey vessel covered each area as effectively as possible in the time allowed. New areas were studied where the cruise route permitted, including the Outer Hebrides, finding sharks around offshore frontal systems. During this time, hundreds of images have been obtained using digital still and video recording of individuals to establish matches with previously sighted sharks, using a technique known as photo-identification. A database (www.baskingsharks.co.uk) containing identifiable characteristics of individual basking sharks has benefited over the years from the large number of images contributed from the survey. Colin Speedie, skipper of 'Forever Changes' said, "The database helps us to identify individuals far more accurately. In one case, we had one basking shark that we successfully photo-identified, that we re-sighted on two further occasions in the Hebrides".  

In addition to this the project has also advanced our understanding of the sharks distribution along the west coast, identifying hotspots of activity and areas which could benefit from further protection. As the main prey species of basking sharks is zooplankton, the survey has also investigated the effects of climate change, with the basking shark being an indicator species, so heavily reliant on the plankton for it's survival. The final survey report, examining the effects of climate change should be available soon.

After 10 years of survey it is however, time to move on. We have addressed all of our original aims and objectives and have taken the project, in its current form, as far as possible. It is now time to re-assess where our efforts should be focused. As we do this, we wish to say a huge THANK YOU to all of the volunteers and crew who took part in the survey and made the crucial research which we carry out possible. We are currently planning new means of research and investigation into the basking shark, which will appear on this site very soon!