Seaweed: marine life coming ashore

British seaweeds are among our most underrated resources and hugely important for the ecology of the seas, but they get nothing like the recognition that, say, a wild meadow or ancient woodland gets.

There are more than 700 species of seaweed growing in British waters and some have long been harvested for food. Probably the best known is the seaweed Ulva that is made into laverbread. British seaweeds are still harvested in Scotland, Wales and Cornwall, and the potential for cultivating seaweed in British waters is vast.

Even though seaweeds for food fell out of fashion until recently they are now enjoying a renaissance in restaurants and supermarkets, though many of these are imports.

Apart from food, the demand for seaweed – for biofuels, pharmaceuticals, toothpaste, fertiliser and industrial gels – is booming. The industry is worth more than £5bn worldwide. There is interest in finding new drugs from seaweed. In the food industry alginates are used in ice cream, they also improve the foaming head on beer and allow fast setting in puddings. They are used too in cosmetics, medicines, paints, and lots more besides.

There is particular interest in seaweed farming for biogas and that could become a significant renewable energy for the west coast of Scotland in particular. Seaweed would be harvested and broken down in digesters to release methane gas for heating and electricity – all without using fresh water, chemical fertilisers or valuable farmland.

The cultivation of seaweed fights climate change, soaking up carbon dioxide and locking carbon away. And for added benefit, seaweed grows far faster than land plants, making it even more efficient at getting rid of carbon dioxide.