Seaweed: the heart of a new bio-based economy

A zero-input crop

Mention macro algae to a friend and most likely you’ll get a puzzled look. Many will think of spirulina but a few will say — you mean seaweed? Yes! Seaweed is really a catch all term for a family of >10,000 macroscopic, multicellular red, brown and green marine algae.

These aquatic plants can grow up to 2m a day and come in a wild variety of shapes, sizes and colors. They contain a dizzying array of chemical and bioactive compounds which scientists are investigating for application in everything from human therapeutics and cosmetics to biopolymers and fertilizers.

Today, ~35 species of seaweed are commercially cultivated, with more than >98% grown in Asia (more data on this later). Unlike terrestrial crops, seaweed requires no land, no synthetic fertilizers or pesticides and no freshwater to grow. It is a zero input crop.

Towards a new blue/green economy

Seaweeds are the trees of the ocean. Like forests, they provide a range of beneficial ecosystem services. They cycle nutrients, sucking up excessive amounts of nitrogen and ammonia, whilst generating oxygen and reducing ocean acidification. They provide a rich habitat for fish and other marine life. Furthermore a recent study suggests seaweeds even help to sequester carbon at the bottom of the ocean.

In many developed countries, coastal communities and family businesses have been hard hit as fishing fleets scaled up and moved offshore. Growing seaweed offers a chance for local economic renewal, providing counter-seasonal jobs (in the northern hemisphere, seaweed is grown over the winter, counter cyclical to the fishing season).

Meanwhile, biorefining seaweed — a green manufacturing technique to convert seaweed biomass into higher value products such biopolymers, fertilizers, pharmaceutical compounds — promises to deliver the next generation of ecologically sound products. Using this approach we can build a new blue (ocean) / green (sustainable) economy.

Marine Minnow or Agricultural Superpower?

Yet if seaweed has so much potential, why is it more of a marine minnow than an agricultural superpower? In future posts we will explore how new investment flows and technologies are boosting production, how scientists and entrepreneurs are building new markets, and how a new playbook to convert raw biomass into sellable products at scale can unlock its true potential.