Meet the new US entrepreneurs farming seaweed for food and fuel

As the world grows and the climate changes, there's been fresh interest in seaweed - and a new breed of farmers are exploring how best to harness the humble plant's benefits

Michael Graham reaches into a bright blue tub of bubbling water and pulls out a handful of a dark brown curly substance. It's slippery to the touch, smells like the sea, and tastes a bit like salty kale.

It's live seaweed, and Graham - a kelp biologist and the creator of Monterey Bay Seaweeds - has been farming the stuff on a small scale in these big tanks in Moss Landing on the central coast of California for close to two years. Using more than a dozen of these big tubs and a couple of larger tanks, he produces between 50 and 100lbs of seaweed per week.