lunes, 7 de marzo de 2016

PICTURE Sharks in the UK


© BBC Wildlife Magazine
If you ask someone to picture a shark, they will probably think of a large, powerful apex predator such as a great white. Now tell them that up to a dozen big shark species – possibly including the great white – occur off British coasts. I bet their expression will swiftly change to surprise, then perhaps alarm or outright fear.
The UK’s roll call of large predatory sharks includes the blue, shortfin mako, smooth hammerhead, common thresher, porbeagle (a smaller version of the great white) and tope, not to mention less-familiar species such as the bluntnose sixgill and Greenland shark.
These fish are mostly seasonal visitors that have been using our seas for millennia, so when I read headlines saying that Jaws has been spotted off Cornwall, I despair.
As soon as anyone gets remotely near to a big shark (other than a basking shark) in UK waters, the media go into overdrive. The reporting of these ‘close encounters’ often does sharks a great disservice. In August, for example, a 2m-long porbeagle caught off the Inner Hebrides was widely described as a “bad, bad fish” in the press.
In September there was a story about a “ravenous” blue shark that “attacked” an angling boat off Cornwall. The way in which this incident was reported played upon the tired old Jaws cliché, misrepresenting the actual behaviour of the shark, which had been attracted by a bait bag (an onion sack of mashed-up mackerel). It was just doing what sharks do. Sensational news? Hardly.
Myth and reality
Our fear of sharks is based on three things. First, they hit basic human fear buttons: of being eaten, of being out of our natural element, and of the unknown. Second, they have always been regarded as mindless killers, even though attacks are rare – and fatal attacks even rarer. Finally, we love monsters, so seldom stop to reflect on the fact that, of nearly 500 shark species worldwide, only a handful are dangerous to us.
The ultimate headline creator is the great white, and scarcely does a British summer go by without another ‘sighting’. Concrete proof is lacking – the ‘evidence’ tends to be fuzzy photos or anglers’ eyewitness reports of hooked or netted sharks that escaped before they could be examined properly.
But this summer a lobster fisherman called me to say that he had found a huge, serrated, triangular tooth embedded in one of his creels off the coast of Scotland. Was this proof of a British great white?
When I saw the photo, I confirmed that it was indeed the tooth of a great white – but a fossil. Experts later confirmed it to be about 10,000 years old. Indeed, great whites are – or were – native to British waters.
It’s not surprising: conditions are perfect for them here – Britain’s seal colonies provide abundant prey, and the water temperature is similar to that off South Africa (in fact, great whites can cope with much colder water – they have been recorded in the Bering Sea, for instance.)
So do great whites still patrol our waters today? Is it too far-fetched to imagine them featuring on Springwatch?


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