Fish dominate the planet's waters through their astonishing variety of shape and behaviour. The beautiful weedy sea dragon looks like a creature from a fairytale, and the male protects their eggs by carrying them on his tail for months. The sarcastic fringehead, meanwhile, appears to turn its head inside out when it fights. Slow-motion cameras show the flying fish gliding through the air like a flock of birds and capture the world's fastest swimmer, the sailfish, plucking sardines from a shoal at 70 mph. And the tiny Hawaiian goby undertakes one of nature's most daunting journeys, climbing a massive waterfall to find safe pools for breeding.

An elegantly filmed documentary, Planet Ocean takes us on a beautiful adventure into the strangest domains of our planet - the oceans. The film features both the magnificence and the exposure of Earth's oceans. The dangers that threaten the whole planet also threaten us. We are guided through various series of events (sailfish relying on mackerel; mackerel relying on zooplankton; zooplankton relying on marine prairie) it is not simply to demonstrate the function of a food chain, but to illustrate the way in which all life is intrinsically interconnected. What happens to our oceans happens to our selves.