Turning the Tide:
A Startup’s Mission to Restore Balance to Coastal Ecosystems

Thalasso’s technology harvests invasive sargassum seaweed, while its micro-biorefineries turn the ecosystem-disrupting material into a circular-economic revenue generator for affected communities.

By Scarlett Buckley | Published 4 months ago | About a 5 minute read

Image: Thalasso

When it comes to sustainability innovation, seaweed has become a hero on many fronts: From its carbon-sequestration ability to its potential as next-generation packaging materials, methane-reducing livestock feed, sustainable dyes and more, the marine superplant offers innumerable environmental benefits and practical, circular applications.

However, one type of seaweed has not received the same appreciation for its potential: sargassum — a prolific alga that plagues beaches across the Caribbean, USA, Mexico and West Africa. Known for its buoyant, brown, leafy appearance, this relentless invader devastates coastal environments and ecosystems — smothering vital habitats such as coral reefs and seagrass beds, and depleting oxygen levels in the water. To add insult to injury, the pungent odor emitted by decaying sargassum repels tourists — turning once-vibrant beaches into malodorous landscapes — which is devastating for coastal communities reliant on tourism revenue.

These algal blooms thrive in the vast expanse known as the Great Sargassum Belt — a sprawling stretch of oceanic territory where up to 100 million tonnes grow annually. The relentless growth is exacerbated by climate change — which alters ocean currents and temperatures, providing optimal conditions for its proliferation. Additionally, the influx of synthetic fertilizers into the Atlantic Ocean contributes to nutrient-rich waters that further fuel sargassum blooms. Despite global efforts, eradicating sargassum remains a daunting endeavor.

Thalasso

Enter Thalasso — a Norwegian startup whose Ocean Harvester technology and micro-biorefineries offer a circular solution for both harvesting sargassum from affected coastal areas and transform it into valuable products. Co-founded by serial entrepreneur Frode Sønstebø and Paulina Zanela — an international relations expert with a background in marine-ecosystem management, social impact, NGOs and government affairs — in 2019, Thalasso was born from a shared epiphany at the intersection of global water solutions.

“We were among 10 companies attending a World Bank, Panama government and IE Business School Madrid event focusing on global water solutions. After the event, Paulina and I realized that we had synergies to pursue the sargassum issue with the knowledge we had from each part,” Sønstebø told Sustainable Brands® (SB). “A few months later, leveraging Paulina’s connection with the Mexican government and the experience of the Norwegian company I worked with — which specialized in assembling technology on boats — we decided to join forces and establish a company dedicated to finding solutions for harvesting and sustainable management of sargassum seaweed.”

Harvesting sargassum

Thalasso’s autonomous Ocean Harvester is being developed to harvest sargassum in a way that is both sustainable and applicable. Powered by electricity and equipped with battery-driven systems, the harvester will integrate solar panels into its design to partially fuel its energy needs. The harvester will be equipped with the technology to detect nearby sargassum, tracking its movement, and is also designed to minimize harm to marine life, incorporating features to prevent bycatch. Each harvester boat will be able to collect 20-40 tons per hour.

With the influx of sargassum more pronounced than ever across thousands of kilometers and hundreds of beaches, solutions such as Thalasso’s can’t come soon enough. The Ocean Harvester is in final stages of development, with Sønstebø anticipating that it will be ready for testing early next year and a vessel equipped with its packing solution to follow shortly after: “Developing innovative solutions takes time, especially when parts of the technology need to be invented. We have been focusing on trials for our automatic packing solution, which has been built partly and tested,” he explained.

From menace to resource

After the Ocean Harvester has collected the sargassum, Thalasso's network of mobile micro-biorefineries can convert the unwelcome seaweed into valuable chemical compounds for industries including agriculture, pharmaceuticals, cosmetics, food, feed, fashion, textiles and bioplastics.

“The micro-biorefinery is still in development; but we've conducted previous laboratory tests, which have provided us with valuable insights and experience,” Zanela told SB. “Given the vast amount of sargassum available, amounting to millions of tons, it represents a significant source of biomass — making it highly valuable, regardless of individual yields. Where some may perceive it as waste, we see it as a game-changing opportunity.”

Unlike traditional biorefineries, Thalasso's micro-biorefineries are easy to install — making them suitable for remote seaweed farms. By enabling on-site conversion of seaweed into high-value products, these refineries promote sustainable utilization of marine resources while mitigating transportation emissions.

“The pilot refinery currently processes 1.5 tons of sargassum per day, but we’re hoping to scale it in terms of capacity and amount of refineries very soon. Plus, the sun-drying protocol is expected to dry and store many more tons,” Sønstebø explained.

Along with the environmental benefits of removing the invasive algae from the affected ecosystems, the micro-biorefineries will support economic growth and job creation in the affected areas. By engaging local communities, Thalasso aims to create jobs in harvesting, processing and research — driving inclusive, sustainable economic development in affected coastal regions.

“We envision the combination of innovation, sustainability and community empowerment shaping the overarching narrative of ocean conservation and economic development,” Zanela asserted. “Our harvester and micro-biorefinery illustrate this vision by utilizing sargassum as a valuable resource across multiple industries, supporting both innovative and sustainable practices.”