Sargassum, long considered a scourge of the Caribbean, is now at the heart of an innovative project in Saint Vincent and the Grenadines. The archipelago is embarking on a pilot initiative to transform this brown seaweed into agricultural and economic resources. This approach illustrates the small islands’ determination to move from an environmental constraint to a sustainable development strategy, by focusing on the blue economy.
A phenomenon that's shaking up the Caribbean
Since 2011, the massive proliferation of sargassum has become a major problem in the region. This brown algae, mainly from the species Sargassum natans and S. fluitans, forms huge floating rafts every year, drifting from West Africa to the Caribbean coast and the Gulf of Mexico. In 2018, more than a million tons covered Mexican beaches, marking a turning point in regional awareness of this phenomenon.
The consequences are far-reaching: disruption to tourism, damage to fishing equipment, obstruction of harbours and a threat to public health. As they decompose, they release hydrogen sulfide, a toxic gas that can cause respiratory problems. For island states, managing this scourge represents considerable costs, making a value-added approach essential.
An international pilot project
Against this backdrop, Saint Vincent and the Grenadines has become the setting for an ambitious experiment. British company Seafields Solutions Ltd has teamed up with local company Private Refuse and Garbage Disposal (PRGD) to implement a pilot sargassum recovery project, scheduled to run from September 2025 to April 2026.
With funding of $15 million, this initiative is part of the “Unleashing the Blue Economy in the Caribbean” (UBEC) program, supported by the Organization of Eastern Caribbean States (OECS) and the World Bank. It combines advanced maritime technologies, supplied by Seafields, with PRGD’s operational know-how in the field.
The system includes specialized vessels, floating barriers and offshore storage areas to manage seaweed flows. Once harvested, they are processed locally, creating a value chain of direct benefit to the island’s economy.
From biochar to biostimulants: promising agricultural outlets
The central aim of this project is to convert sargassum into high value-added products, useful for sustainable agriculture. There are two main thrusts:
- 💡Biochar, obtained from the carbonization of algae, improves soil structure, increases its water retention capacity and promotes plant growth. Agricultural yields observed with biochar sometimes exceed those obtained with chemical fertilizers, reaching over 4 tonnes per hectare.
- 💡Biostimulants, extracted from algae, boost crop resistance to climatic stress and improve nutrient absorption. They also reduce the use of nitrogen fertilizers by almost 30%, contributing to more environmentally-friendly agriculture.
Economic and social benefits
The implementation of this pilot project has a direct impact on local communities. By creating jobs in harvesting, transporting, processing and marketing by-products, sargassum recovery generates new sources of income. It also reduces the costs associated with clean-up operations, which are often very burdensome for public finances.
As Seafields CEO John Auckland explains:
“This partnership demonstrates how sargassum, once seen as a costly burden, can become a valuable, job-creating resource.”
The aim is also to perpetuate this industry through the creation of a joint venture, Seafields SVG, which could become a model for other Caribbean territories facing the same challenge.
A growing regional dynamic
Saint Vincent and the Grenadines is not an isolated case. Across the Caribbean, entrepreneurs and institutions are exploring the valorization of sargassum. In January 2025, the Inter-American Development Bank (IDB) and its IDB Lab innovation laboratory launched the Sargassum Innovation Quest, designed to support the most promising projects.
In Barbados, entrepreneur Joshua Forte has been transforming sargassum into organic compost through his company Red Diamond Compost since 2014. In Guadeloupe, SUEZ is working on the production of organic fertilizers and the decontamination of chlordecone-contaminated soil. In the Dominican Republic, SOS Carbon is working with Origin by Ocean to develop fertilizers and animal feed. In Mexico, C-Combinator is exploring the production of ecological leather and biostimulants.
This regional effervescence shows that the Caribbean is gradually moving towards an integrated blue economy, where sargassum is no longer perceived solely as a threat.
An opportunity for the Caribbean
The pilot project launched in Saint Vincent and the Grenadines illustrates a change in approach to environmental crises. Rather than endure the massive arrival of sargassum, the archipelago has chosen to transform it into a lever for growth. This strategy is fully in line with the objectives of the blue economy, which aims to make sustainable use of marine resources while protecting ecosystems.
By leveraging technology, innovation and regional cooperation, Saint Vincent and the Grenadines is paving the way for a new way of looking at the future of sargassum in the Caribbean.
