Washington: A 5,000-mile seaweed belt lurking in the Atlantic Ocean is expected in the next few months to wash onto beaches in the Caribbean Sea, South Florida, and the Yucatán Peninsula in Mexico.
The Great Atlantic Sargassum Belt — as the biomass stretching from West Africa to the Gulf of Mexico is called — contains scattered patches of seaweed on the open sea, rather than one continuous blob of sargassum. It’s not a new occurrence, but satellite images captured in February showed an earlier start than usual for such a large accumulation in the open ocean.
Once it washes ashore, sargassum is a nuisance — a thick, brown algae that carpets beaches, releasing a pungent smell as it decays and entangling humans and animals who step into it. For hotels and resorts, clearing the stuff off beaches can amount to a round-the-clock operation.
Here’s a look at this year’s sargassum seaweed bloom:
What is Sargassum?
A leafy brown seaweed festooned with what look like berries. The seaweed floats on the open ocean and — unlike other seaweeds — reproduces on the water’s surface, helped by air-filled structures that give it buoyancy.
Sargassum originates in a vast stretch of the Atlantic Ocean called the Sargasso Sea, which lies well off the southeast U.S. The Sargasso has no land boundaries; instead, four prevailing ocean currents form its boundaries.
The matted brown seaweed stretches for miles across the ocean and provides breeding ground, food and habitat for fish, sea turtles and marine birds, according to the National Oceanic and Atmospheric Administration.
“It’s a dynamic, constantly changing set of pieces of this large mass,” said Rick Lumpkin, director of the Physical Oceanography Division at NOAA. “It’s not one big continuous blob heading straight to South Florida.”
Why is it a problem?
Sargassum piles up on beaches where it quickly decomposes under hot sun, releasing gases that smell like rotten eggs.
In recent years, sargassum has carpeted beaches on some Caribbean islands and Mexico’s Yucatán Peninsula in the spring and summer months. Beach towns and cities and hotels have struggled to keep up with the huge amounts of seaweed that wash ashore.
Is Sargassum harmful to human health?
It can be. When sargassum decomposes, it releases ammonia and hydrogen sulfide, which accounts for the rotten-egg stench. Brief exposure isn’t enough to make people sick, but prolonged exposure — especially for those with respiratory issues — can be dangerous, scientists say.
Hu said it could be an issue for hotel workers and others who may spend hours removing the decomposing sargassum from beaches.
Left to rot on the beach, sargassum can turn into a problem. It can harm coastal marine ecosystems and also supports the growth of fecal bacteria.