Record Sargassum Bloom Hits Florida, Caribbean Beaches

Quintana Roo, Mexico — A record-breaking bloom of toxic sargassum seaweed, now spanning 5,500 miles across the Atlantic Ocean, is advancing toward the beaches of Florida and the Caribbean. The massive algae invasion, estimated at 31 million tons, has already surpassed the previous record set in June 2022 by 40%, according to researchers.

A Growing Ecological and Economic Crisis

The sargassum bloom, while a natural phenomenon, has reached unprecedented levels in recent years, damaging ecosystems and local economies dependent on tourism. Floating in dense brown mats, the seaweed emits harmful gases as it decomposes on shorelines, creating a foul odor and deterring visitors.

Brian LaPointe, a research professor at Florida Atlantic University’s Harbor Branch Oceanographic Institute, explained the severity of the issue: “What we’ve seen since 2011 are excessive flooding events across the Caribbean, the Gulf, and southern Florida. Sargassum transitions from a beneficial resource in the North Atlantic to what we call a harmful algal bloom when it reaches the coast in excessive biomass.”

Climate Change and Agricultural Runoff Fuel the Bloom

Rising ocean temperatures due to human-caused climate change have accelerated sargassum growth. However, LaPointe identified another critical factor: excess nitrogen from agricultural fertilizers. These nutrients, washed into the Mississippi and Amazon rivers, eventually flow into the Atlantic, feeding the algae’s explosive expansion.

“Severe droughts in large watersheds dry out organic matter. When rain returns, it flushes concentrated nitrogen and phosphorus into the ocean, fueling massive sargassum growth,” LaPointe noted.

Impact on Tourism and Coastal Communities

The seaweed has already appeared along Florida’s east coast, from the Keys to St. Augustine, and is spreading across popular destinations in Mexico, Barbados, and beyond. In Miami, boats at Dinner Key Marina were recently surrounded by thick mats of sargassum.

Quintana Roo’s government is collaborating with the Mexican Navy to remove the algae from coastal waters. Governor Mara Lezama emphasized the urgency of mitigation efforts to protect the region’s tourism-driven economy.

A Historical Phenomenon with Modern Consequences

Sargassum has existed for centuries—Christopher Columbus encountered it in the Sargasso Sea—but its current scale is unprecedented. “What we’re seeing now goes far beyond historical levels,” LaPointe said.

As the bloom continues to grow, coastal communities brace for further disruptions, highlighting the need for long-term solutions to address the intertwined challenges of climate change and nutrient pollution.