From providing a green alternative to plastics to reducing methane emissions and sucking carbon dioxide out of the atmosphere, seaweed could be the secret ingredient we need to clean up our planet
13 May 2020
AS A CHILD in South Wales, I was dimly aware that laverbread was a treasured cultural asset. Nobody I knew ate any, though, and it never turned up on my plate. I would probably have turned my nose up at it if it had. Far from being bread as most of us know it, this traditional Welsh foodstuff consists of seaweed boiled into a mushy paste, often dipped in oatmeal and fried before serving. Not my childhood self’s ideal dish.
For many people, seaweed is something we trip over on the beach, not take there in our lunch boxes. But for thousands of years, humans have harnessed seaweed in extraordinary ways. Our ancestors ate it, farmed it and used it as fertiliser. When humans first entered North America from Asia more than 13,000 years ago, their survival may have depended on fish that were plentiful thanks to coastal kelp.
Today, we still rely on seaweed’s many benefits. We use it as a delicacy to wrap round sushi, extract its chemicals for use in industry and turn it into recyclable plastics. But its potential doesn’t end there. Large-scale seaweed farms could clean up Earth’s oceans, restoring biodiversity and increasing the productivity of aquaculture. They could suck carbon dioxide from the air, and help curb the emission of other greenhouse gases. According to some researchers, it could even be crucial to saving civilisation.
Seaweed still has a long way to go to fulfil those lofty ambitions. Some wild populations have been overharvested, and the potential for farming has barely been tapped. But even if it fails to meet …