‘Like a 40-metre pizza’: the seaweed farms that could feed us all – at a cost

Mammoth efforts to grow seaweed are springing up in the Philippines and beyond, and they’re in line for Elon Musk’s ‘largest incentive prize in history’. Meddling with the ocean to grow them, however, has some scientists troubled

A white metal platform on the surface of the Pacific Ocean faces another, smaller one some distance away. Sam Donohue stands on the big platform, Gorio Pepito on the small one. They press buttons, and a high-pitched whirring sets in.

Pepito and Donohue release the buttons. The whirring stops. They communicate by walkie-talkie. Everything’s OK. A crab walks across the big platform: that’s their pet, Donohue says. They press the buttons again.