The Wildlife Trusts' Basking Shark Project

The Basking Shark

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.

Basking shark hotpots in the UK 

The report launched in at the end of 2008 was the culmination of more than eight years’ boat-based study of the UK’s largest fish. The report identifys basking shark hotspots – places where sharks congregate at the surface - revealing a remarkable change in shark distribution over the study period with a marked decline in sightings in the south west of England.

To date it has been difficult to identify practical measures to address these threats and ensure the survival and recovery of basking sharks in UK seas. However, the conclusion is now clear: appropriate protection of basking shark hotspots may be critical to the survival of this threatened animal.

Click here if you wish to download a copy of The Wildlife Trusts report, published 2008.

Click here to download a copy of the Natural England Research Report, published 2008.

Click here to download a copy of the Environment and Heritage (now Northern Ireland Environment Agency) Report, published 2004. 

Click here to download a copy of the Scottish Natural Heritage Report, published in 2009.

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. 

After 10 years of survey it is however, time to move on. The work will continue through Cornwall, Devon and Manx Wildlife Trusts, all of whom have ongoing shore and smaller boat-based studies. As we move on, 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 NEED YOUR HELP!

Cornwall Wildlife Trust is looking for volunteers to assist with its continued annual basking shark monitoring with its 2010 Seaquest Basking Shark Project, thanks to funding from British International Helicopters.

If you have an interest in marine life, love the outdoors and aren’t afraid of spending long hours in the field then we need your help! We are looking for committed volunteers to join the survey; anyone over 16 years old can get involved and are welcome to join us. To find out more please email us on baskingshark@cornwt.demon.co.uk or call Tom Hardy, Marine Conservation Officer on (01872) 273939 ext 208.