THE ocean may seem deep and vast - even limitless - but it's not immune from our influence.
A new documentary aims to raise awareness about the dire state of affairs just off our shores before it's too late.
Blue is the Australian equivalent of Al Gore's An Inconvenient Truth, highlighting the immense changes and decline in health of the world's ocean ecosystems.
Filmmaker Karina Holden and her passionate ocean guardians argue that now is a critical time for the conservation of a rapidly declining resource.
Studies show half of all marine life has been lost in the past 40 years, and researchers project that at current rates of pollution there will be more plastic in the ocean than fish by 2050.
Marine biologist Lucas Handley is one of the faces of Blue, covering issues like fisheries management, coral bleaching and keystone species protection. "I give a general perspective of the ocean as a freediver and marine scientist, having spent my life exploring the most remote places in the world I can get to," he tells Weekend.
Growing up in Byron Bay, Lucas fell in love with the ocean and learned how to explore it for minutes at a time on just one breath of air.
"One of the greatest things about Byron was that we were pushed to have an open mind about different things," he says.
"When I grew up there it wasn't a marine park (at Cape Byron) and we were able to fish there. When the marine park came in there was a lot of resistance to change, but as those things changed people realised that there were many benefits to having a marine park. The greatest thing that came out of the park was not necessarily the blanket conservation in terms of numbers of fish; it was the mentality shift... now we're seeing people take pride in their natural environment."
From surfing the waves of Bells Beach to hand-feeding wild sharks over an active underwater volcano, escaping whirlpools in the Malacca Strait and hunting with his indigenous friends to free diving deep sea pinnacles in the Andaman Sea, Lucas spends as much time underwater as on land.
"I've spent a long time living with an indigenous community in the Solomon Islands, where we need to hunt our food every day," he says.
"I don't want to be one of those people who says we have to lock everything up to conserve it."
He believes the majority of the population has been given a false sense of the seemingly limitless productivity of the oceans thanks to documentaries, tourism campaigns and travel stories.
"Even though we see these images of incredible abundance, it's not necessarily like that," he says. "When people see beautiful images of huge schools of fish they think 'Wow, they must be everywhere' but the science is showing it's a false perception of abundance."
But it's not all doom and gloom. Blue proposes a range of small- and large-scale changes that can help marine ecosystems recover. Lucas believes Blue should appeal to a wide range of viewers and hopes it's not dismissed as a "greenie'' film.
"One of the important things here is we're not pushing an extreme, change your entire life to save the planet agenda," he says. "We're saying there are all these issues and you can do your own small thing, from the way you eat to what you choose to consume and the throwaway plastics you're using.
"It doesn't mean you have to go quit your job and become an activist. What the film hopes to do is empower people to make one small change in their life."
Blue screens in select cinemas from Thursday.
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