Mac the knife

Coral reef sharks face a catastrophic world-wide population collapse if present fishing levels remain unrestricted, say scientists from James Cook University. Even on the relatively well protected Great Barrier Reef major shark species survive at just a fraction of prior levels, and they say numbers are declining.

The global picture beyond reefs may be even worse. A recent study by Shelley Clarke and colleagues at the University of Hawaii found that at least four times as many sharks are killed for their fins as are reported in official figures. That may mean 73 million per year.

By contrast, sharks are estimated to kill not much more than a dozen people world wide every year. It is said that ten times as many people are killed by falling coconuts.

Australian researchers William Robins and Sean Connolly say there are three reasons that sharks are more valuable alive than dead: tourist dollars, a sustainable fishing industry and reef protection. The third of these -- reef protection -- is not obvious to non-specialists, and a clear explanation of the role of reef sharks in reef ecology would be helpful.

Western popular imagination, insatiable in externalising its monsters, groans under a mountain of cliche about sharks. But now that many species are endangered could the conservation advocacy of the likes of Peter Benchley in his last years outlast his pulp fiction?

Not all mythology about sharks is antipathetic. See, for example, this brief oultline of traditional Hawaian beliefs.

So a combination of clear science, and old and new stories may help to change the picture.

It may even be the case that demand for shark fin soup in some East Asian countries can be reduced. Campaigns by organisations such as Wild Aid in countries such as Thailand, working with celebrities to drive home the message that eating shark is not cool (and may even stunt male virility), have had some impact.

"Und der Haifisch, der hat Zähne
Und die trägt er im Gesicht
Und MacHeath, der hat ein Messer
Doch das Messer sieht man nicht."

("And the shark, he has teeth
And he wears them in his face
And MacHeath, he has a knife
But the knife you don't see.")

Photograph copyright Warner Bros Entertainment Inc. Photo by Peter Kragh shows Howard Hall and Bob Cranston with the 3D IMAX camera system taken during the filming of the IMAX 3D film Deep Sea 3D