The eastern shores of Cuba, particularly along the southern coast of Guantánamo, are facing a severe crisis as an overwhelming influx of sargassum transforms once pristine beaches into expansive fields of decomposing seaweed. Coastal communities such as Baitiquirí and El Guanal are witnessing their natural environments drastically altered. The Guantánamo Fishing Company issued a warning on social media about the scale of this event, which coincides with the start of summer, making fishing, beach leisure activities, and other marine endeavors highly unpleasant.
Local journalist Miguel Noticias has characterized this as a "sargassum strike," detailing the dire environmental conditions burdening the area. Residents are suffering from the stench produced by decomposing seaweed, experiencing respiratory issues, seeing the death of fish and other marine life, and noting corrosion on metal infrastructure and household items. "This natural phenomenon suffocates marine ecosystems, deters tourism, and jeopardizes local fishing," he warned.
The environmental devastation and social discomfort are exacerbated by a lack of resources to manage the cleanup. This influx of sargassum is not a new occurrence on Cuban shores. In May 2025, a historic accumulation of nearly 38 million tons of floating sargassum was recorded in the tropical Atlantic, far surpassing the previous record of 22 million in 2022. Some scientific forecasts suggest the global volume could exceed 40 million tons in the coming months, posing an unprecedented threat to the Caribbean.
The repercussions of sargassum extend beyond mere aesthetics. Upon reaching land, it decays, releasing hydrogen sulfide, a gas with a strong odor that irritates the eyes and respiratory system and degrades air quality. In the ocean, sargassum obstructs sunlight, elevates water temperatures, and depletes oxygen levels, severely impacting ecosystems such as coral reefs, seagrass beds, and populations of turtles, sea urchins, and fish.
The complexity of this phenomenon is tied to global processes. Nutrient discharge—like nitrogen and phosphorus—from rivers such as the Amazon, coupled with climate change and shifts in ocean currents, has excessively fertilized the Atlantic, driving the massive growth and migration of sargassum toward Caribbean shores. While countries like Mexico have launched special operations with marine barriers, collection vessels, and treatment facilities to mitigate the impact, Cuba's limited technical and logistical resources hinder an effective response.
In the Dominican Republic and other Caribbean islands, measures such as floating barriers, preventive closures, and health campaigns have been implemented. There are also emerging initiatives to repurpose sargassum into fertilizers, bricks, or bioplastics, though scalability remains a challenge. Experts agree that addressing this crisis requires a coordinated regional strategy. Satellite monitoring systems, offshore collection, investments in treatment infrastructure, and sustainable economic utilization models are needed. International cooperation—through organizations like Caricom, ECLAC, or the UN—will be crucial to tackling a phenomenon that is no longer merely seasonal but structural, and threatens to escalate in the coming years.
Meanwhile, in eastern Cuba, coastal communities continue to wait for a tangible solution as their beaches become natural dumping grounds, and their way of life is caught in the waves of sargassum.
Understanding the Sargassum Crisis in the Caribbean
What is causing the massive sargassum influx in the Caribbean?
The massive influx of sargassum is linked to global processes, including nutrient discharge from rivers like the Amazon, climate change, and changes in ocean currents. These factors have excessively fertilized the Atlantic, promoting the growth and movement of sargassum towards Caribbean coasts.
How does sargassum affect local ecosystems and communities?
Sargassum affects ecosystems by blocking sunlight, warming waters, and reducing oxygen levels, which harms coral reefs, seagrass beds, and marine species. For communities, it causes respiratory issues due to the strong odor of decaying seaweed and disrupts tourism and fishing activities.
What measures are being taken to address the sargassum problem?
Countries like Mexico are using marine barriers, collection vessels, and treatment plants to mitigate the impact. Elsewhere, floating barriers, preventive closures, and health campaigns have been implemented, along with initiatives to convert sargassum into useful products like fertilizers and bioplastics.