- Writing
- BBC News World
image source, Getty Images
A huge mass of algae is approaching the Caribbean and Mexico.
Its regarding Atlantic sargassum beltwhich travels year-round, from West Africa to the Gulf of Mexico, and which has grown more than ever.
This year it has a length of approximately 8,800 kilometers and weighs 10 million tons.
The mass of sargassum is so large that the only way to see the entire belt is from space.
“Almost every year we are seeing a bloom that It’s like nothing we’ve seen before, because it’s getting bigger and bigger.“Brian Barnes, from the University of South Florida (United States), told the BBC.
Sargassum is a “brown macroalgae that floats on the ocean’s surface,” according to the University of South Florida’s Laboratory of Optical Oceanography.
However, it is not a “contiguous mass,” Barnes explains. The smallest sargassum patch seen in satellite imagery is the size of a football field, though the largest can reach up to 2.5 square kilometers.
According to the Quintana Roo Sargassum Monitoring Network, in the Mexican Yucatan peninsula, where Cancun, Playa del Carmen and Tulum are located, among other tourist sites, only four of 80 beaches were without sargassum this Thursday, although only 12 they had an “excessive” amount.
image source, Optical Oceanography Laboratory of the University
Satellite images show the scale of the kelp belt.
“We have seen a increase in quantity (of sargassum) in the first half of March. Most of the sargassum layers are still entering the Caribbean Sea from the east and continue to move west to reach the Mexican Yucatan coast. In general, some beaches in the Caribbean Sea have received and will receive variable amounts of sargassum, but not all beaches will see that“explained Chuanmin Hu, a professor at the University of South Florida.
“It is to be hoped that sargassum impacte the eastern part of the Yucatan peninsula (both Belize and Mexico) and the beaches of the Greater and Lesser Antilles. The size and frequency of that sargassum buildup offshore may increase in the coming months,” Barnes added.
Sargassum is an important habitat for marine life, but following 48 hours on shore, the algae begin to emit toxins like hydrogen sulfide that, in small amounts, smells like rotten eggs.
In environmental terms, sargassum “can smother sea turtle nests on the beach” and release “plumes of dissolved organic matter, which can impact nearshore environments and their inhabitants,” Barnes said.
Worse than the smell, hydrogen sulfide can cause headaches, eye irritation and stomach upset if present in large amounts, according to the US Centers for Disease Control and Prevention.
The exact reason for the growth of sargassum is still being studied.
Hu said seaweeds need “sufficient sunlight, warm water and enough nutrients from different sources” to grow rapidly. He added that the “elongated belt is formed due to ocean currents and surface winds.”
One contributing factor, Barnes noted, might be the Amazon basin, which has seen an increase in nitrogen that then fertilizes the sargassum.
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