Record levels of sargassum threaten Caribbean tourism and coastal ecosystems
- A record amount of sargassum, 38 million metric tons, was reported across the Caribbean in May 2025.
- The unusual volume has raised concerns for coastal ecosystems and impacted tourism-dependent local economies.
- Experts caution that without adequate measures, the continuing growth of sargassum could worsen in future years.
In May 2025, Puerto Rico and the surrounding Caribbean regions faced an unprecedented influx of sargassum seaweed, totaling 38 million metric tons. This amount marks the highest recorded since the monitoring of the Great Atlantic Sargassum Belt began in 2011. The drastic increase from the previous year's record of 22 million metric tons has raised concerns among biologists and environmentalists regarding the factors contributing to this phenomenon. Although the precise causes remain uncertain, hypotheses include climate change, agricultural runoff, and alterations in local ocean currents and winds. Despite serving as a vital ecosystem for marine life in the open ocean, the sargassum's encroachment on shore poses significant challenges for coastal communities. As the seaweed clogs beaches and produces foul odors when decomposing, it disrupts tourism, a critical economic driver for numerous Caribbean islands. Regions like Punta Cana in the Dominican Republic have taken precautionary measures such as installing barriers to mitigate the arrival of sargassum, while other areas have initiated emergency clean-up operations to address the situation. The impact extends beyond environmental concerns; local governments are pressured to allocate funds for cleanup efforts, further straining resources in regions that already struggle financially. Some hotels are taking an active role in mitigating effects by offering guests alternative beach options, reflecting the operational upheaval within the tourism sector. Additionally, in St. Maarten, residents experienced severe fumes related to the seaweed's decay, highlighting health concerns associated with significant sargassum influxes. As summer approaches, experts continue to monitor the situation, forecasting an ongoing rise in sargassum amounts during June, particularly within the western Caribbean and Gulf regions. This pattern of frequent sargassum blooms has prompted discussions about the environmental and economic sustainability of tourism-dependent regions, as both experts and local authorities grapple with diminishing resources for adapting to and managing this natural phenomenon. The context of the increasing sargassum in the Caribbean emphasizes a need for broader conversations about climate-related changes impacting marine ecosystems and coastal economies.