BLACKFISH, a documentary about an orca, or killer whale, that literally becomes a killer, offers a powerful insight into the lives of these majestic creatures and the consequences of what can happen when they are ripped apart from their intricate family structures to provide amusement for humans in theme parks.

Produced by Dogwoof, the same company responsible for Food Inc and The end of the Line, and billed as “a mesmerising psychological thriller, which shows how nature can get revenge on man when pushed to its limits”, BLACKFISH was never going to be easy to watch, and there are plenty of confronting scenes.

Premiering at the Sundance Film Festival in the US earlier this year to critical acclaim, BLACKFISH tells the story of Tilikum, a performing whale captured as a two-year old who was ultimately responsible for the deaths of three people while in captivity.

It follows his path from capture to placement in various Sea World theme parks, revealing how his treatment ultimately caused the psychosis that led to the attacks on the park’s trainers.

Director Gabriela Cowperthwaite has, through a combination of archival footage and numerous interviews with both whale experts and Sea World trainers, past and present, made a taut and compelling documentary which gives the viewer a vivid insight into the extraordinary nature of these animals, the horror of their captivity and the pressures brought to bear on the trainers in the multibillion-dollar sea park industry, whilst also challenging the viewer to consider our relationship with nature as a whole.

It also reveals just how little was known about orcas and the complexity of their communities when the theme park industry sprung up in the 70s. The footage of ORCA, KILLER WHALE, released at roughly the same time as JAWS, did about as much for the understanding of orcas as JAWS did for sharks. In fact, as one whale expert pointed out, there is actually not one reliable documented case of an orca harming a human in the wild.

But place one in an oversized bathtub 20 metres wide by 30 metres deep when they are used to roaming up to 180 kilometres a day and a case such as Tilikum’s was bound to ensue.

Some of the more challenging footage in the film involved the marks left by Tilikum’s fellow whales which were constantly attacking him, the result of the tiny spaces they were confined in and the fact that they were effectively left in darkness for two thirds of their lives.

And whilst there will be the inevitable comparisons with 1993’s Free Willy, BLACKFISH succeeds by packing a lot of information into a genuinely thought-provoking narrative, viewing the tragedy from a number of angles.

One of these is the often-complex nature of the relationships between the trainers and the whales. The film contains numerous interviews with ex trainers who genuinely believed they had made real and lasting bonds with the whales. Some undoubtedly had, yet the real tragedy of Tilikum’s story is how, with all the best intentions in the world, even the most faithful of handlers were powerless against the unpredictability of wild animals kept in these conditions, borne out by shocking footage of the physical injuries suffered by the males, virtually all of which had collapsed dorsal fins.

For its part, Sea World plays the role of evil, heartless multinational to perfection, with everything from the appalling treatment of the whales to its equally awful treatment of the trainers, to its denial that there was anything amiss in courtroom statements following the tragedies involving the deaths of the trainers.

According to one interview with an ex-trainer, there were at least 70 documented cases of training accidents and mishaps involving Sea World trainers that was never disclosed to him when he accepted his position.

To her credit, Cowperthwaite goes out of her way to debunk the lies spread by Sea World such as the one that killer whales actually live longer in captivity, something which research has shown to be blatantly false.

There is a lot to like about BLACKFISH in the way in which it exposes this industry for what it is. Having said that, it seemed almost a shame that it took these human tragedies, as awful as they were, to bring attention to the shameful exploitation of these highly intelligent, sentient fellow mammals.

As one of the experts interviewed said, in 50 years time people will look back at these theme parks and wonder at their barbarity.

BLACKFISH opens nationally on Thursday November 21. It has received an M rating and has a running time of 79 minutes.