Grenada explores the ways to turn sargassum seaweed into biofuel, fertilizer and cosmetic

Caribbean nations are grappling with extensive blooms of sargassum—a type of brown algae that has transformed from a rare occurrence into an annual challenge exacerbated by climate change and water pollution. Typically seen as a nuisance that impedes tourism and fishing and incurs substantial cleanup expenses, sargassum is now being reconsidered as a potential resource for generating renewable fuel, fertilizer, and other value-added products.

In Grenada, where annual seaweed influxes have imposed financial and operational strains since 2011, government officials and private companies are actively developing projects to harvest sargassum before it reaches the beaches. The strategy aims not only to alleviate the economic burden of constant beach-clearing operations but also to repurpose algae as an alternative energy source and soil amendment. Grenada’s special envoy for oceans, Jerry Enoe, emphasized the importance of viewing sargassum as an opportunity rather than merely a menace.

At a recent conference hosted in October, Caribbean representatives and European Union officials discussed collaborative measures to convert sargassum into a green industry. Grenadian Prime Minister Dickon Mitchell announced an ambitious target to process 10,000 tons of seaweed into useful products by 2026. The initiative has attracted pitches from 33 companies, with several projects slated for summer funding.

The applications under consideration are diverse. Scientists and start-ups across the region, including efforts in Mexico and international academic institutions, are exploring ways to transform biomass into bricks, biofuels, and even pharmaceuticals. One notable initiative, led by the start-up SarGas founded in 2023, involves a digester that uses bacteria to convert sargassum into methane. This methane, rather than being released into the atmosphere, is harnessed for local energy needs—initially to fuel a bakery’s oven and potentially to generate electricity for Grenada’s power grid. This approach is particularly significant in a setting where imported diesel currently dominates the energy mix, inflating costs and environmental impacts.

The rationale behind these initiatives is multifaceted. Beyond providing an alternative source of fuel, utilizing sargassum may reduce greenhouse gas emissions associated with diesel generators and the unmanaged decay of seaweed in landfills. The biogas generated could also serve as a reliable complement to solar power, especially during nighttime hours, thereby contributing to a more stable local energy grid.

However, the challenges are nontrivial. The unpredictable nature of sargassum blooms complicates the planning and investment required for collection infrastructure. Moreover, converting seaweed into fertilizer is hindered by its high salt content and accumulation of toxic metals such as arsenic, necessitating additional processing before it can be safely applied to agricultural fields.

In addition to energy and fertilizer applications, there is an interest in chemically extracting compounds from sargassum for use in cosmetics and pharmaceuticals. Although this represents a longer-term and capital-intensive venture, firms in Mexico and proposals for Grenada’s establishment of a biorefinery underscore the breadth of potential opportunities that this abundant natural resource might offer.

Overall, while the path to turning sargassum from an environmental burden into a sustainable asset remains complex, regional cooperation and innovative technological solutions are charting a course that could yield significant environmental and economic benefits for Caribbean nations.