HALF of all marine life has been lost in the last 40 years.
By 2050 there will be more plastic in the sea than fish.
Blue, a film by director Karina Holden, takes audiences on a journey into the ocean realm, witnessing a critical moment in time when the marine world is on a precipice.
The film features passionate advocates for ocean preservation.
One of them is Byron-raised Lucas Handley, a marine biologist worried about the ocean's future.
"The ocean has always seemed a place of limitless supply, infinitely bountiful," he said.
"No one ever imagined that we could do anything to harm the ocean: by what we put into it... or by what we took out of it."
Blue takes audiences into Handley's world, where the story of our changing ocean is unfolding.
Besides the marine biologist, the film features people defending habitats, campaigning for smarter fishing, combating marine pollution and fighting for the protection of keystone species.
At Pighouse Flicks from this Saturday. For details visit bbff.com.au.
Here is a short film about Handley's work in Tonga.