It's in your yoghurt, your toothpaste and possibly your next pair of boots. Dominique Olivier explains how seaweed moved from slimy beach nuisance to one of the planet's most valuable - and greenest - economies.

Beneath the waves, a silent collapse is underway. As fish stocks dwindle, so do the jobs, meals and communities built around them. But it’s not too late for us to make a meaningful change. Dominique Olivier explains how to balance conservation with people whose livelihoods depend on the ocean.