Tuesday, July 14, 2009

Shark Cage-diving


Ecotourism might well be a way of saving some of the sharks. If living animals are more valuable to locals than dead ones, they might survive.

Jaws - What Great White Sharks Eat

The Great White Shark (Carcharodon carcharias) was made famous by Steven Spielberg's film ‘Jaws’, where it is portrayed as a rather malevolent creature intent on eating humans. This is probably not true, and it is thought that Great Whites bite humans ‘by mistake’ more often than not. Their preferred prey (seals and large fish) have much more fat than the average human swimmer, and it has even been suggested that they cannot easily digest humans!

The normal hunting strategy of the Great White Shark is to attack once, and then wait around until the prey becomes a bit weaker before going in for a meal. Humans usually manage to get out of the water before the final stage, and many survive. Biologist Douglas Long has been quoted as saying that ‘more people are killed in the U.S. each year by dogs than have been killed by great white sharks in the last 100 years’. (This does not help if you are one of the few!).

Intelligence of Great White Sharks

All predators have complex behaviour, and many seem to have some sort of intelligence. Great Whites are quite social (for sharks) and are very curious. They are one of the very few species of shark that will ‘spy-hop’ to look around. This behaviour lifts the head out of the water and is something that Killer Whales also do. Since Great Whites rarely survive long in captivity there have been few studies of their mental capacities, but observation in the wild seem to suggest that they might be one of the few animals that will ‘play’ – by dragging bits of seaweed along behind themselves.

Great White Sharks' Enemies

Only Humans and Killer Whales pose any real threat to Great White Sharks, and, of course, other Great Whites! While they can be social at times, they can also be cannibals. Killer Whales rarely attack them, but humans often do – a set of jaws can be worth as much as £20,000, and the fins are quite valuable too. Great Whites will eat Dolphins, but Dolphins have also been reported as ‘mobbing’ Great Whites on occasion, and even killing them with repeated ramming.

Cage-diving

Rather like whale watching, cage-diving attracts enthusiasts. Here divers go down inside robust metal cages and sharks are lured to the scene. This form of ecotourism gives the diver/tourists an immense adrenaline rush, and incidentally makes shark conservation worthwhile. Jaws might be worth £20,000, but a single boat can make as much every day there are paying tourists.

Shark Conservation

Many species of shark are endangered. Maybe ecotourism can help by making the living animal more valuable to local fishermen than the fins or teeth? When a single species, such as the Great White is actively conserved huge numbers of other species, and the habitat, are also saved. So, if you enjoy having yourself scared almost-to-death, then ‘go for it’ – you might be helping preserve one of nature’s most misunderstood predators.