Sharks are in serious trouble. Research this week has revealed that more than half the world's ocean-going sharks face extinction in the near future. I first became aware of their plight in 1999, on an assignment in the Galapagos Islands. Instead of photographing them, I wound up cutting dying sharks from illegal long lines. The experience led me to investigate the huge demand for sharks - even in the best-protected national parks on earth.
The simple reason is shark fin soup. Through much of Asia, this is a symbol of wealth, served as a sign of respect. A single pound of shark fin can sell for more than $300. Shark bodies don't have substantial value, so fishermen started discarding the bodies and keeping only the fins. People have also been falsely led to believe that shark cartilage can cure conditions such as arthritis and cancer. In fact, it has been proved that shark cartilage has no disease-beating properties.
Each year, 100 million sharks are killed and no one bats an eyelid, largely because the public is petrified of sharks. The reality, as most divers know, is that sharks are mostly harmless to humans. Of the 350 known species, only a few pose a hazard. In 2002, I set out to make a film that would bring people closer to sharks. I thought if people could understand them, and see them as beautiful, necessary animals, they wouldn't be afraid. I joined Paul Watson, founder of the Sea Shepherd Conservation Society, on an expedition to deter poaching in the ill-protected Cocos Island reserve.
This journey shifted the focus of the project from a beautiful underwater film to a drama full of corrupt governments, attempted murder charges and machine-gun chases, all because of the demand for shark fin and cartilage. Studies by scientists of Dalhousie University, in the Canadian city of Halifax, suggest that Atlantic shark populations have declined as much as 89% since 1972. This week's study, from the International Union for the Conservation of Nature, confirms the crisis.
Only in 2004 was the first fish placed on the Convention on International Trade in Endangered Species, followed by some sharks, which just happen to be the most recognisable - the great white - or those like the basking and whale sharks that support thriving tourist industries. Protection is much more difficult to acquire for less charismatic, but equally or more gravely endangered species such as Borneo, snaggletooth, angel and whitefin topeshark.
Our failure to protect the oceans is largely because we don't see underwater exploitation the same way we see it on land. We waste 54bn pounds of fish every year, and all fisheries worldwide are expected to collapse by 2048. We are, however, capable of great change if made aware of the issue. We have turned the situation for whales around through public pressure, creating the International Whaling Commission. In the same way, sharks can be saved.
Big strides were made earlier this year when Whole Foods Market announced it would stop selling shark cartilage products. Legal precedent was set in the US when another company selling cartilage was forced to refund customers' money. The fact that huge organisations are taking notice is the first step to saving sharks from extinction.
I still run into people who hang on to the misconception that sharks are the frightening, man-eating monsters portrayed in the movie Jaws. But since the release of my film - Sharkwater - I've been thrilled to meet so many people who now understand that humans are in fact far more dangerous to sharks than sharks are to us.
The killing of tiger, panda or elephant is now taboo, and the same can be done for sharks. It comes down to an issue of awareness.
Rod Stewart, the director of Sharkwater.