A massive 8,850 km-long brown “algae belt” is spreading from Africa to the Gulf of Mexico, alarming scientists across the globe. Officially named The Great Atlantic Sargassum Belt (GASB), this floating mass of brown seaweed now weighs more than 37.5 million tons and is visible even from space.
Originally confined to the Sargasso Sea, it was first detected spreading widely in 2011 — and has since doubled in size almost every year.
What Is Sargassum and Why Is It Dangerous?
Sargassum is a type of floating seaweed (algae) that once served as a natural habitat for small fish and marine organisms. However, the balance broke when this algae began expanding beyond its original boundary.
Fueled by nutrient-rich waters loaded with nitrogen and phosphorus from agricultural runoff, sewage, and industrial waste, the algae now spreads uncontrollably across the Atlantic.
Scientists Sound Alarm: Nitrogen Surge and Climate Change
A study by Florida Atlantic University’s Harbour Branch Oceanographic Institute found that between 1980 and 2020, nitrogen levels in Sargassum increased by 55%, while the nitrogen-phosphorus ratio rose by 50%.
The Amazon River is believed to be the primary contributor, carrying industrial and agricultural waste into the Atlantic. From there, ocean currents like the Gulf Stream and Loop Current transport this “brown ribbon” all the way to Mexico.
Impact on Marine Life and Climate
When the algae mass accumulates on the sea surface, it blocks sunlight from reaching coral reefs, halting photosynthesis and damaging marine ecosystems. As it decomposes, it releases methane, hydrogen sulfide, and other greenhouse gases — accelerating climate change.
Beached Sargassum also produces toxic gases and unbearable odors, turning coastal tourist areas into health hazards.
Economic Fallout: Tourism and Power Disruptions
This ecological crisis is also an economic one. Beaches covered in Sargassum deter tourists, hurt the fishing industry, and force local governments to spend millions on cleanup operations.
In 1991, a nuclear power plant in Florida had to shut down temporarily after Sargassum clogged its cooling system — proving it’s not just a “marine weed,” but a full-blown environmental emergency.
Climate Change: The Perfect Growth Recipe
Scientists say climate change has created the “perfect temperature zone” for Sargassum growth. Rising sea temperatures, shifting winds, and altered ocean currents are helping this algae spread further north each year.
If unchecked, experts warn that this “Sargassum Monster” could soon engulf the entire Caribbean and US coastlines.
