After being boosted by the recent heat wave, massive amounts of zooplankton is now attracting record numbers of basking sharks into British and Irish waters.

Last year, 26 basking sharks were reported from the most southerly headland of Cornwall during a 10 week long period. This year, 900 sightings have been recorded since the beginning of June.

“Last year we had a really poor year because of the weather. But even though temperatures have obviously picked up, we never expected to see the sharks in such large numbers,” saysTom Hardy of Cornwall Wildlife Trust, coordinator of the south-west basking shark project.

Record breaking numbers of basking sharks are being reported from the other side of Irish Sea as well. In June alone, the Irish Whale and Dolphin Group reports having seen no less than 248 basking sharks.

“In a three-day period we tagged more than 100 sharks in just one bay in north
Donegal,” says Simon Berrow of the Irish Whale and Dolphin Group. “You only ever see five or six of these creatures on the surface, which doesn’t reflect what’s going on under the water.”

From the Isle of Man, 400 sightings have been reported since early May.

‘”We saw a lot more in May than is usual and after a couple of quiet weeks sightings are picking up again,” said Fiona Gell, marine wildlife officer for the Isle of Man government.

Very little is known about the basking sharks, but the Irish Whale and Dolphin Group is currently carrying out a pioneering tagging project in hope of furthering our understanding of these basking giants. Simultaneously, the 47 wildlife trusts found across the UK, the Isle of Man and Alderney are working to identify basking shark hotspots.

Scientists tagging sharks off the Irish coast have tagged a surprisingly high number of Basking sharks this year: 50 specimens in just three days.

“I would normally expect to be lucky if we tagged 50 in a whole year,” said Dr Simon Berrow of the Irish Whale and Dolphin Group.

Basking SharkA record

Together with National Parks and Wildlife Service conservation ranger Emmett Johnston, Dr Berrow set out earlier this week to tag sharks off Donegal, as part of a project funded by the Heritage Council.

“In two hours last Monday we tagged 23 sharks, and we found 19 the following day – four of which had been tagged the day before,” Dr Berrow said. By the third day, they had tagged their 50^th basking shark.

Basking sharks were once a significant source of income for Irish whalers and the coastal towns of Galway and Waterford did for instance have street lights lit with basking shark oil as early as the 18^th century.

The importance of Basking sharks in Irish culture is evident in the number of names and monikers give to these peculiar creatures. In Irish, this “monster with sails” is known under the names Liabhán chor gréine (Great fish of the sun), Liop an dá (unwieldy beast with two finns) and Liabhán mór (great leviathan) – just to mention a few. The epithets “Fish of the sun” and “Sunfish” both pertains to its fondness of swimming just under the surface.

In the mid-1970s the Irish stopped their whaling, but the problems weren’t over for these sharks since they frequently ended up as by-catch in drift nets; a fishing method now outlawed in Irish waters. In addition to this, Norwegian whalers continued to hunt for shark off the Irish coast until 1986.

The Basking shark (Cetorhinus maximus) is listed as Vulnerable on the IUCN Red List of Threatened Species, and is a protected species in Great Britain but not in Ireland. However, the European Union has just placed a moratorium on fishing for Basking sharks in these waters.

If you spot a Basking shark in Irish waters, the Irish Whale and Dolphin Group would very much like to know any details about the sighting. You can find more information at www.baskingshark.ie.

Want to know more about Basking sharks and where they head when the Northern Seas become too cold for comfort? Check out our earlier blog post on Sharks of the Caribbean.