An overview on seaweed uses in the UK: Past, present and future

The UK has a coastline in excess of 31,400 km and has macroalgae growing off-shore for the majority of its length (Fig 1). An estimated 10 million tonnes of seaweed surrounds the Scottish shores alone. Seaweed grows rapidly and is capable of yielding more kg of dry biomass m-2 year-1 than fast growing terrestrial crops such as sugarcane, due to its ability to take up nutrients over its entire surface and a lack of lignin-like energy-intensive supporting tissue which is necessary for land plants. Seaweed also has a number of significant benefits over terrestrial crops including not being a food, not requiring land or fresh water and having rapid growth. Despite this, seaweed is not currently used to its full potential in the UK with factors for this including the availability of cheap imports and a lack of mechanical harvesting processes. Historically, though, seaweed has been used much more extensively for a number of purposes.