Sharkwater

Think of sharks, and you probably think of the monstrous, man-eating predators filling the screen with their fins and teeth in Steven Spielberg's Jaws (1975), Renny Harlin's Deep Blue Sea (1999) and Chris Kentis' Open Water (2003). Which is to say that sharks suffer from a severe image problem. They entirely lack the sort of charismatic qualities that we so readily project onto apes, elephants, penguins and pandas, and they have been traduced by a demonic mythology that bears little or no resemblance to reality. Championing their cause is akin to taking on PR work for, well, a cold-blooded killer.

Yet that is exactly what underwater photographer, biologist and ecologist Rob Stewart does in his documentary Sharkwater, playing advocate to the seemingly indefensible creatures armed only with a camera, a strong sense of self-dramatisation, and a raft of facts. His voice-over declaration of a life-long love of sharks, accompanied by footage of him embracing a no doubt surprised specimen in the waters, is hardly going to persuade everyone of the creatures' all-round toothsome cuddliness, but the arguments that Stewart and his interviewees offer for the shark's primary place in our planet's ecology are far more compelling and to the point.

You do not have to love sharks to acknowledge their evolution-shaping contribution to ecosystems beneath the ocean and above, or to recognise the danger that their fast-approaching extinction at our hands might pose to all life on earth (an infinitely greater danger, it turns out, than their presence in the water actually poses to humans).

In a sense, all this reflects precisely what is good and what is not so good about Stewart's film. The raw data on sharks that he has assembled, and his beautiful underwater photography, serve to tell their story with pellucidity – but it is precisely when Stewart inserts himself into this story that the waters begin to get muddied, as the film heads away from the deep and into the shallows.

Stewart's strategy is to show himself in constant danger – but, importantly, not from the sharks he is so determined to protect, but rather from a conspiracy of mercenary poachers, corrupt governments, shark-fin mafia, and freak illness. This is what might be called the Michael Moore effect, whereby a complicated argument is made palatable by being transformed into an adventure with the filmmaker at its centre. The problem with the approach is that it can often seem more of a distraction from, rather than an advancement of, the film's principal proposition. This is certainly the case with Sharkwater.

In 2002, Stewart joined conservation activist Paul Watson board the Ocean Warrior. Watson was heading for Cocos Island, where he had been invited by no less than the President of Costa Rica to patrol the shark-rich waters for any poaching activity. Stewart was tagging along to film some sharks. Yet before reaching their destination, they encountered a boat full of shark poachers in Guatemalan waters, and engaged it in a violent game of cat-and-mouse in an attempt to stop it fishing and to bring it to shore for the authorities.

Eventually reaching Costa Rica, the environmentalists found themselves facing seven counts of attempted murder, and were placed under house arrest pending the trial – but they sneaked out to make surreptitious recordings of illegal shark-fin processing plants organised by the Taiwanese mafia in private docks. Believing that they were unlikely to win in court, and that there were gangsters gunning for them in town, Stewart, Watson and the rest of the crew fled into international waters, aggressively pursued by the Costa Rican coast guard. And then, off the Galapagos Islands, Stewart was hospitalised for a week with 'flesh-eating disease', facing the possible loss of a leg, or even of his life. Will the intrepid cameraman ever get to swim with his beloved sharks again?

This gripping high-seas yarn, complete with defiant pirates, gunboat chases, narrow escapes and exotic illnesses, forms the backbone of Watson's film, as he dramatises the forces ranged not only against the world's rapidly dwindling shark population, but also against his own plans to make an underwater movie.

Upon reflection, however, Stewart's excitable narrative prompts many uncomfortable questions. No matter what one might think about illegal poaching or the cruelties of shark-finning, do Watson's strong-arm vigilante tactics not warrant some sort of judicial examination? Might, for example, deliberately ramming a small manned boat in open waters not reasonably be construed as attempted murder? Is it not just possible that the coast guard was pursuing Watson and company simply because they had breached the conditions of their house arrest and were attempting to evade trial on serious charges, rather than because, as Stewart suggests, they were getting too close to uncovering the links between government and poaching? Was the Taiwanese mafia really pursuing Stewart all over Costa Rica (the evidence that he adduces for this is all strictly hearsay)? And what exactly did Stewart's illness, for all its potential gravity, have to do with sharks?

Stewart's over-precious comment on the saline solution being fed into his ailing body speaks volumes: "Now that I couldn't be in the ocean, they were dripping the ocean into me." This is a filmmaker desperately trying – and failing – to find some sort of larger relevance in his own personal experience. A more experienced director would have cut this sequence out faster than ruthless poachers strip sharks of their valuable appendages.

At best, the 'reality drama' that unfolds on-screen takes viewers away from the real ecological issue (much as it took Stewart away from his diving), and at worst it tends to dilute Stewart's status and credibility as self-appointed champion of all that is right. At one point, Watson asserts that it was individuals such as Mahatma Gandhi who changed the world, the implication being that Watson and his fellow activists represent a similar force for good in a world that is wilfully destroying itself.

No doubt Watson and Stewart do have their heart in the right place, but unlike Gandhi, they are conspicuously reluctant to face up to the consequences, legal or otherwise, of their political actions, preferring flight to due judicial process - and that, I think, tends to undermine the moral validity of their position. Even worse, such undermining was entirely unnecessary – if Stewart had focused more on sharks and less on his own misadventures, then the sharks could have had their day in the court of cinema without any needless and unhelpful interjections from their own defence team.

When Sharkwater is providing an account of sharks based in history, evolutionary theory and observational science, when it is debunking popular myths about sharks, and when it is exposing the monstrously murderous predations that our own species has recently been perpetrating upon the shark at an unsustainable rate and at unquantifiable cost to all life on the planet, then the film is excellent. When, however, it is forced to enter the complications of international politics, it becomes a fish out of water, flailing about for a purpose that it is not sophisticated enough to fulfil. Which is a pity, because Stewart's main argument needs urgently to be heard, and has real teeth.