We know what you’re thinking. Der dud. Der dud. Der dud, der dud, der dud… But forget Jaws — if you’re confronted by a grey fin while splashing around the west coast this summer, there’s no reason to flee screaming from the water. The culprit is more likely to be a cruiser than a bruiser.
While the sight of a basking shark — the world’s second largest fish (the whale shark pips it to the title) — may set your heart racing, these 10m-long gentle giants really aren’t interested in human ready-meals. They are passive filter feeders, gliding through the water and using their 1m-wide mouth and five sieve-like gills to strain the plankton from up to 2,000 tonnes of water every hour.
The key to their feeding success is in their name. The sharks bask just below the surface, their dorsal and tail fins breaking through the water. This is the perfect depth for maximising their catch of tiny crustaceans and plants, which are abundant on our western seaboard in summer.
The majestic creatures are able to cruise at this level because of their enormous liver. The organ makes up 25 per cent of their weight — about 1.5 tonnes, roughly the same as an average car. It’s stuffed full of oil that is lighter than water, making the creatures particularly buoyant.
But travelling at this depth is a mixed blessing. It makes the docile sharks an easy catch, and susceptible to collisions with boats. Their numbers have declined rapidly since the 1950s, at first because of the high demand for their livers, which are used as an aphrodisiac by the Japanese and as a source of oil in the cosmetics industry. Today, the threat comes more from the Far East market for shark fin soup.
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The sharks’ problems are compounded by their slow maturation time and low reproduction rates, which make it hard for their dwindling population to recover. So bad has the problem become that the fish are classified as “endangered” in the northeast Atlantic.
But there’s one place where these magnificent animals can still bask in all their glory. They are now fully protected by law in UK waters and the Shark Trust has produced a code of conduct for swimmers and boat owners wanting to get a closer look (they say swimmers are safe just 4m from the animals). So this summer there’s no excuse not to get out and do a little basking yourself.
Jaws? Perhaps Dumbo is more appropriate.
All eaters great and small
(by stomach capacity)
Asian elephant 80kg
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Basking shark 600kg
Blue whale 1,000kg
Cow 120kg
Human (Joey “Jaws” Chestnut, hot dog eating world champion) 4.75kg
Lion 30kg
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Mayfly (adult) 0kg (it doesn’t ever eat)
Reticulated python 60kg
Water buffalo 130kg