Critics reviews

The beauty of Chasing Coral enhances the tragedy of its findings, and when the team's time-lapse cameras prove ineffective the emotions hit hard. Underwater camera technician Zack Rago, a self-professed "coral nerd", begins manually taking photos each day to create a time-lapse of the Great Barrier Reef. His pain at seeing a once thriving underwater habitat crumble is palpable, and the image of him swimming through a desolate wasteland will stay with you long after the credits roll.

No doubt most people have read the occasional news story about the world's coral reefs disappearing at an alarming rate, but so far this has been the very definition of an "out of sight, out of mind" problem. By all indications, "Chasing Coral" could be a game changer in terms of public perception. Like Al Gore's "An Inconvenient Truth" and Louis Psihoyos' "The Cove" in years past, the film makes a powerful case less through argument than by using cinema's most basic tool: visual proof.

This film, more than its predecessor, frequently adopts the soporific rhythms of reality TV, cutting back and forth between preparations and explanations. But [it] has a cogent, timely argument to make—and, crucially, it's an argument that demands visual presentation. For once, reading a book or in-depth article on the subject wouldn't be remotely as persuasive (except perhaps regarding the question of whether human activity is primarily responsible). If your eyes work, your heart will sink.

The journey takes Orlowski and others — including former ad exec Richard Vevers and young camera technician Zack Rago, a coral buff who plays an increasingly prominent role in the film — all over the world as they try to find a way to document and lay bare the horrifying sight of a mass global-bleaching event. Spoiler alert:They succeed, and the final act of this film is one of the most harrowing things I've ever seen.

What makes it play as more than just another activist doc is its focus on the power of images as a way to inspire change.

The documentary "Chasing Coral," which has its premiere on Netflix on Friday, July 14, opens, appropriately enough, with images of coral — formations in various shapes and sizes, all of them stunning, charged with an array of colors so vivid they seem to pulsate. Other formations are a uniform hybrid of purple, green and gray. This isn't stealth coral, or coral donning camouflage. It's dead coral. Which is a problem.