More on the Greenland Sharks Story.
There was a big reaction from BBC Wildlife readers following the publication of a story in the October issue on the mysterious, fatal ‘corkscrew’ injuries that have been inflicted on British seals in the past two years.
This was followed by the transmission of a programme on Channel 5 about grey seals off Sable Island (a 44km sandbar about 150km off the coast of mainland Novia Scotia) that were also dying from mysterious ‘corkscrew’ wounds.
The programme, eventually, fingered the Greenland shark, better known as a cold-water Arctic scavenger than a hot-blooded predator.
Were the two cases related? Could Greenland sharks be taking out British seals?
Well, a bit of digging has revealed some interesting facts. First of all, British scientists do not consider the Greenland shark to be a credible answer to the mystery of our seal deaths.
They are only largely found under the polar ice cap, so a migration to the North Sea would take one well out of its usual range.
Second, not everyone agrees that Greenland sharks are behind the Sable Island seal deaths. BBC Wildlife has contacted two scientists who appeared in the Channel 5 film and who are two of the world’s experts on Greenland sharks.
In brief, they don’t believe that Greenland sharks are found around Sable Island, and they don’t see why they should attack and mutilate the seals without then eating them.
But according to Zoe Lucas, a naturalist who lives on Sable Island and the person who has done more than anyone to investigate this issue, Greenland sharks are still top of her agenda, and she and other scientists working on the issue have eliminated ships’ propellers as a possible cause.
You would have thought that it would be easy to determine how such extraordinary wounds are inflicted, but it appears not. In the meantime, BBC Wildlife will keep you up-to-date with any developments.
2. Zoe Lucas
Claims to be a biologist and went to Sable Island to study the horses that live there. In an interview on her work by CBC Television she was asked what she did for a living ( how she sustained herself in such a remote place) clearly she was not funded by a grant from any research establishment. Her reply was as follows.
‘I work as a biologist conducting research and monitoring programs. If by "living" you mean what do I do for income, I conduct environmental monitoring programs for the offshore energy industry’
The offshore industry in question is as follows.
Shell Canada Ltd.
Esso Imperial Oil.
Pengrowth Energy Trust.
Mosbacher Operating Ltd.
These companies form a consortium that operate several gas platforms just offshore from Sable Island ( I didn’t see them in the channel 5 Program did you?) Here is an extract from their web site.
‘The Sable Project is the largest construction project ever undertaken in Nova Scotia. We’re proud of what we’ve accomplished. We’ve established an infrastructure that will be the basis of our production efforts for the future. Those efforts are changing the face of the Nova Scotia economy, and providing an alternative energy resource to consumers throughout the Maritimes and the Eastern United States.
‘The Sable Offshore Energy Project is divided into two 'tiers' of offshore development. The first tier was completed in December 1999 and involved the development of the The baud, North Triumph, and Venture fields, as well as the construction of three offshore platforms, an onshore gas plant and an onshore fractionation plant. Gas production commenced on December 31, 1999. Alma, the first Tier II platform came on stream in late 2003 while production from South Venture, the second field began late in 2004.’
3. Finally an extract from this web site.
These scientists were involved in and clearly misrepresented by the Channel 5 program.
The actual cause of the corkscrew wound is probably mechanical. If this is the case, the culprits are almost certainly dynamic positioning thrusters used by vessels associated with offshore drilling or construction. Such operations are present off all sites reporting corkscrew wounds. Seals are curious creatures often seen diving near shipwrecks and other man-made objects. The powerful suction effect produced by a thruster would easily overpower a seal that got too close. Unlike regular ship propellers that run continuously while a ship is at sea, thrusters operate on a need-only basis and thus turn on and off sporadically.
A curious seal inspecting the intake side of this odd tunnel-like object would have no chance if the power were suddenly turned on. Being sucked into the blades would either slice the hapless seal to death or produce the horrific wounds witnessed at Sable Island and in the UK. Some of the butchered seals may even survive and swim back to the beach to die.
The Greenland shark does leave a trademark wound on its victims but this most certainly isn't it. We therefore believe that corkscrew fatalities at Sable Island and in the UK are in fact unrelated to the Greenland shark.
Human activity is yet again the likely cause for these needless deaths. Who knows how many lifeless bodies didn’t actually make it to shore? Life is dangerous enough for seals without having to deal with giant underwater food processors. If I were a seal, I'd choose the shark. I would at least have a fighting chance to survive, and if I were defeated, my death would serve to sustain a fellow creature of the sea.
Godfrey Sayers 12/10/2010
Godfrey Sayers 12/10/2010