By Felicia J. Persaud in Barbados

News Americas, BRIDGETOWN, Barbados, Weds. June 18, 2025: The turquoise waters and white-sand beaches of Barbados – long celebrated as a jewel of the Caribbean – are under siege. A thick, brown tide of sargassum seaweed now dominates many of the beaches, turning once-pristine shores into foul-smelling, uninviting sands of discontent.

Seaweed pile up outside the beach infront the Sands hotel in Christ Church. (Felicia J. Persaud image)

Outside The Sands Hotel, tourists are greeted not by white sand and clear, blue waters, but by huge dark piles of rotting, smelly algae. Fresh sargassum is washing up daily, tainting the water and spoiling the scenic charm that draws visitors from across the globe. The same scene is unfolding on Barbados’ east coast in Bathsheba as well as the remote beach at Skeetes Bay, and across the Caribbean, from Saint Lucia to Puerto Rico.

Rotting seaweed on the beach infront the Sands Hotel in Christ Church, Barbados. (Felicia J.Persaud image)

The decomposing algae is producing toxic gases, including ammonia and hydrogen sulfide, both of which pose a threat to human health.

Scientists warn the invasion is far from over.

The seaweed has turned the usually pristine clear turquoise waters brown. (Felicia J. Persaud image)

According to a new report from the University of South Florida’s Optical Oceanography Lab, a record-breaking 38 million metric tons of sargassum was observed across the Caribbean in May 2025—shattering the previous record of 22 million tons set in 2022. Even more is expected in June.“Sargassum has experienced a robust population so far this year,” said Barry Rosen, professor of ecology at Florida Gulf Coast University.

“Sargassum has experienced a robust population so far this year,” said Barry Rosen, professor of ecology at Florida Gulf Coast University.

The phenomenon is fueled by a complex mix of nutrient-rich runoff from South American rivers, warming ocean temperatures, and changing weather patterns. Droughts in the Amazon in 2023 and 2024 allowed nitrogen and phosphorus to accumulate, and recent floods triggered a massive release into the Atlantic—a “first flush” that scientists believe ignited this year’s explosion of sargassum blooms.

“Sargassum has experienced a robust population so far this year,” said Barry Rosen, professor of ecology at Florida Gulf Coast University.

“It came out of the drought with a vengeance,” said Brian Lapointe, a veteran marine ecologist

While sargassum in open waters helps support marine ecosystems, its arrival in nearshore zones is destructive. The seaweed smothers coral reefs, depletes oxygen, and blocks fish spawning grounds, jeopardizing fragile marine life and island economies. When it rots, it emits hydrogen sulfide gas, which smells like rotten eggs and can cause respiratory problems and skin irritation.

Communities in Saint Lucia report health issues tied to long-term exposure. Fisheries officials report that sargassum is blocking fishing grounds and reducing fish stocks but recent readings show gas levels haven’t yet reached hazardous thresholds, concern is growing.

Meanwhile, the United Nations Development Programme (UNDP) has pledged support for the region, including feasibility studies on reuse strategies and specialized cleanup equipment to help countries like Barbados combat the growing crisis.

Still, officials warn this is not a short-term problem.

Crashing waves bring more seaweed to the shores daily. (Felicia J. Persaud image)

“It came out of the drought with a vengeance,” said Brian Lapointe, a veteran maWe’re exploring how we can utilise sargassum for productive purposes,” said Keith Nichols of the Caribbean Community Climate Change Centre. “But the volumes we are seeing now are unprecedented—we haven’t even fully quantified the impact.”

French Caribbean territories have started using containment booms to control the algae offshore before it hits land—a strategy that Saint Lucia and others may adopt. But the financial burden, ecological damage, and tourism fallout pose steep challenges.

With peak summer tourism around the corner, the Caribbean’s most valuable asset – its beaches – is under threat. Unless coordinated regional action takes hold soon, what was once paradise may quickly become uninhabitable for visitors and residents alike.