Context and Importance
Since around 2011, massive seasonal blooms of the brown macro-algae Sargassum natans and Sargassum fluitans have been washing ashore across the Caribbean region, forming what is known as the Great Atlantic Sargassum Belt. Coastal and marine systems across the Organization of Eastern Caribbean States (OECS) are increasingly facing the recurrent challenge of influxes; a 54% increase in 10 years.
While sargassum plays an important ecological role offshore (providing habitat for marine life), when large volumes strand along coastlines it triggers multiple negative impacts:
The decomposition of stranded sargassum reduces oxygen, emits hydrogen sulfide and ammonia, alters pH, and can cause fish kills and coral/seagrass damage as well as allergic and respiratory diseases to people.
Coastal ecosystems (beaches, reefs, seagrasses, mangroves) suffer from smothering, reduced light penetration, and altered trophic dynamics.
For small island states, the influx presents serious economic, tourism, public health and operational challenges.
There is growing recognition that sargassum can be reframed as a resource rather than only a nuisance: by diverting stranded sargassum into value-chains (e.g., fertilizers, bio-bricks, packaging materials, bioenergy) the region has the potential to generate new jobs, drive innovation in the blue economy, and build resilience. For the OECS, this roadmap is thus both a crisis response and a strategic opportunity: aligning governance, preparedness and innovation to transform an external shock into a region-wide benefit.
