Displaying items by tag: Baskingshark

Wednesday, 26 May 2010 17:38

Tag Team !

While many of us were relaxing on the beaches around the coast of our Atlantic washed Island, a team of Irelands leading marine biologists were hard at work hunting one of Irelands most iconic marine species, the Basking shark. These sharks are no ordinary creatures, growing up to 10m in length and often weighing over 3 tons one would think they are pretty hard to miss. However, miss them we do, for 8 months of the year the basking shark disappears with little trace only to return to our shores in what appears to be ever increasing numbers. Scientists have been baffled for centuries by this creature's habits and life cycle.

The scientific team with the Irish basking shark project, has been operating for only three years, hopes to unravel the behavioural mystery about the second largest fish in the Oceans. The 2010 season started with a splash as the team managed to deploy 100 individual tags on sharks in one weekend off the coast of Malin head and the Inishowen peninsula. Last year the team deployed 106 tags through out the whole season of May - September, and hopes are now high that they can build on this success with further deployments through out the country in Cork, Kerry, Galway and Mayo.

The Irish based team who have quickly become world leaders in the shark research field and are aiming to gather enough robust data on the species to see it gain protection around the Irish coast. Although the E.U. has imposed a zero fishing quota on the basking shark, it is not protected in Irish territorial waters under Irish legislation. The project, which has received assistance from the Heritage Council, works closely with a number of universities including GMIT. This year the team intends to deploy a number of prototype tags, which use satellite and VHF radio waves to track the sharks under and above the water. It is believed these electronic based tags will give the team an increased arsenal in their quest to discover the elusive shark's habits.

For more information log onto www.baskingshark.ie

Published in News

100th Basking shark tagged this season

The 7m Basking shark was tagged off the Blasket Islands, Co Kerry on Sunday 9 August. This was the 100th shark tagged this season, an astonishing success rate. Prior to this year only eight tags had been deployed on basking sharks in Ireland and les than 50 worldwide.

The tagging study, funded by a Heritage Council Wildlife Grant, aims to determine the movements and migration patterns of basking sharks in Ireland and determine growth rates, longevity and other essential life-history characteristics. The deployment of individually coloured numbered tags have been complimented by two satellite tags. “these two different types of tags compliment each other” explained Project Leader Dr Simon Berrow. “the satellite tags are set to track the movements of the sharks for up to seven months and will provide high quality data on location and depth during this period. We hope the coloured tags will remain on the sharks for much longer enabling us to get much longer distance recoveries and see if the sharks return to Ireland the following or in future years”.

At a recent conference on basking sharks in the Isle of Man, the Irish researchers learnt that les than 50 tags have been deployed on basking sharks throughout the world so the Irish tagging project is leading this research.

“Obviously the more tags we deploy the better chance we have of getting a recovery. Already we have eight recoveries from local movements around the tagging sites to over a recovery from Scotland, over 150km away” reported Dr Simon Berrow. Mariners are requested to look out for tagged sharks which have individually numbered green, yellow and red tags on them. Even if you cannot read the number the colour is very useful as they are specific to a county.

The research team also had another significant breakthrough when they showed that basking shark DNA could be extracted from the slime which coats the sharks body. Tissue samples for genetic analysis are hard to obtain as you require a dead shark or invasive biopsy techniques which do not work well on sharks due to their tough skin. By simple rubbing an oven scourer along the sharks body enough slime can be collected to extract shark DNA. This new technique pens up huge possibilities for shark researchers around the world which is very important as basking sharks exhibit surprisingly low genetic diversity.

The research on basking sharks season has been a resounding success and the team are already looking for funding to continue the work next year

Published in News