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It’s silly season, but there is a real shark threat to fear

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Posted August 13, 2013

Each summer, for several years in a row, a tabloid would send me a picture of a shark fin photographed off Cornwall and ask if it was a Great White.“No,” I would patiently explain, “it is a harmless basking shark which feeds on plankton from the seawater”.

“Ah, but could there be Great Whites in the UK?” would be the next question.

“Yes,” I would say. “It is not too cold, we have seal colonies off Cornwall which could attract sharks, and they have a wide oceanic distribution. But numbers of all sharks have been severely depleted worldwide so the chances of seeing a Great White in our waters are rather slim.”

The result of this short interview is invariably the publication of the standard photo of a gaping shark jaw filled with rows of teeth, and a caption that Ken Collins, University of Southampton, says there are Great Whites around our coast. On one occasion this was accompanied by a splendid account from the trembling, fearful reporter of being taken diving off Cornwall and surviving to tell the tale. (This regular nonsense puzzled me until I learnt that the summer shark scare story was worth about £50,000 in increased sales of the paper.)

I administer the UK Shark Tagging Programme which supplies sport anglers around the country with tags and record cards. Over the past 13 years they have tagged and released nearly 10,000 sharks from the few dozen species found in British waters. The most popular are Tope sharks, which grow up to 2m long and appear around the entire coast, Blue sharks, open ocean sharks which can grow up to 3m or more and are more commonly found around the south west, and Smoothound sharks, which can grow to around 1m, prefer inshore southern waters towards France and Spain, and have no teeth.

Occasionally we receive word of impressive catches of larger sharks such as Threshers and Porbeagle sharks. The plastic streamer tags, anchored at the base of the dorsal fin carry a unique number and my contact details so that when the shark is recaptured it is possible to tell how long it has been at sea and how far it has travelled, at minimum, since it was tagged.

The shortfin mako is among the larger sharks occasionally straying into British waters. Credit: Mark Conlin/SWFSC/NOAA

The recapture rate is low, however, about 400 to date and sadly mostly by Spanish and French commercial fishermen, by which time the shark is invariably dead and the weight is reported after gutting. There is a real need for the multinational protection of sharks. Just last month, the long campaign by the Shark Alliance finally resulted in the adoption of an EU regulation that bans, without exception, the removal of shark fins at sea.

The real threat is to sharks, not from them. Many species are now threatened, largely due to the demand for dried shark fins in Southeast Asia. Longline fishing for tuna world wide results in a massive by-catch of sharks which supplies this demand for fins, with an estimated 100 million sharks killed every year – almost 11,000 every hour. Conversely the threat of sharks to humans is trivial: sharks attack and kill only a handful of humans a year, fewer deaths than caused by falling coconuts or vending machines.

Most sport anglers understand the need to conserve the fish they love to catch and are happy to become involved in catch-and-release tagging programmes. And the programme is yielding answers to very basic but little understood matters such as what species occur around the British Isles (more than 30 species of sharks, dogfish, and also rays, which are closely related to sharks), and where and when they appear.

The big threat to sharks has been the demand for dried shark fins in southeast Asia. Longline fishing for tuna results in a massive by-catch of sharks which supplies this demand for fins, estimated somewhere in the region of 100 million sharks per year. Conversely the threat of sharks to humans is trivial – worldwide there are only a handful of human deaths from shark attacks each year, less than from falling coconuts or vending machines.

Selling the conservation message to the general public and the press is more difficult. My starting point is to discuss cod, which most folk are aware of being in decline in UK waters. Cod mature at one year old and can produce a million eggs while the typical shark matures at 10 years old and only produces 10 young; so which is more sustainable, harvesting cod or sharks? Which should be a priority?

Source: The Conversation, story by Ken Collins

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