As well as being farmed for human consumption, animal feed and biofuels, seaweed plays a role in carbon sequestration. In short, carbon is stored in the tissues of seaweed and, when plants die and sink to the ocean floor, the carbon dioxide from the atmosphere is buried along with the biomass.
According to one international study, 48 million km2 of the world’s seas and oceans could be suitable for growing seaweed. By using just 0.001 percent of that area, we could offset the carbon emissions from the entire aquaculture industry.
Seaweed can be a valuable element of a multi-trophic aquaculture system, a sustainable circular production model which is increasingly being used. The process mimics the nutrient flows in natural systems, with seaweed cultivated alongside shellfish such as mussels, oysters and scallops, absorbing some of the otherwise wasted nutrients.
The adoption of new technology can also help the sector to overcome some of the barriers to growth – for example, by gathering valuable information such as light levels in neighbouring waters – to help producers to make informed decisions about the location and set-up of future sites. Technology is undoubtedly becoming a necessary investment to help our aquaculture industry to grow sustainably.
Climate change is, of course, a global challenge but by sharing knowledge from each of these research projects, from company to company, the aquaculture industry can seize new opportunities to improve sustainability. The role of the humble seaweed in mitigating environmental impacts is just one piece of a much larger puzzle, but there is a clear opportunity to integrate it into our aquaculture sector.