AlgaRay to collect and dispose of invasive sargassum

According to the Falmouth-based company, sargassum has been increasing each year due to excess fertiliser, raw sewage and soil runoff. Throughout 2022 record amounts of sargassum are said to have washed up on the shores of Florida, the countries bordering the Gulf of Mexico, Caribbean islands and West Africa.

In a statement, Seaweed Generation’s Chief Science Officer, Professor Mike Allen of Exeter University, said “Unwanted sargassum has increased explosively over the last decade. When these invasive sargassum rafts come ashore they impact coastal ecologies and can lead to significant negative economic consequences.

“The best thing about what we’re doing is that it’s a dual benefit - we can reduce sargassum beaching and remove carbon dioxide at the same time. And we can do it in a way that is incredibly well documented to show its benefits and uphold high environmental standards.”

Seaweed Generation initially plan to deploy two AlgaRays from a support vessel. Travelling through the water at around 3knts, a full forward AlgaRay will descend to a depth beyond 135m where the sargassum is released and is negatively buoyant. The rear AlgaRay then takes over collection and the process is captured on video and recorded with a blockchain.

The company added that AlgaRay ‘s open structure means there is ‘no need for complicated and expensive pressure resistant submarine-like engineering’. A large-scale underwater glide version of the AlgaRay is in development that will carry out the same task ‘with additional capabilities’ including full autonomy.

Seaweed Generation CEO, Paddy Estridge, said: “Carbon removal with seaweed could really scale, and we can do that with cultivation, but there are questions that need to be answered first. Sargassum gives us an amazing opportunity to solve a known problem, whilst conducting the monitoring, reporting and verification that we know carbon removal needs.”

Seaweed Generation raised the funding through AeraVC and Graph Ventures. Derek Handley, founder of Aera VC, said: “We’ve seen a lot of seaweed start-ups trying to tackle CO2, but what convinced us to back…the Seaweed Generation team is that they are solving a significant problem with existing seaweed while being able to sink enormous amounts of carbon autonomously and at scale.”