The giant blob of Sargassum that stretches 5,500 miles across the Atlantic from Africa grew larger than ever last month, scientists report. It’s already hitting beaches in Florida and Mexico, and much more is on the way.
Researchers from the Optical Oceanography Laboratory at the University of South Florida have been studying satellite images of the blog, taken by NASA and other agencies, and measuring its size and direction. They report that it weighed in at 13.5 million tons in March, an all-time-record for that month.
“These blooms are getting bigger and bigger and this year looks like it’s going to be the biggest year on record,” Dr. Brian Lapointe, a research professor at Florida Atlantic University who’s spent his career studying Sargassum algae, told The New York Times.
Each year, ocean currents carry Sargassum from the west coast of Africa up through the Caribbean and into the Gulf of Mexico and south Florida. Scientists started measuring abnormally large amounts of the toxic seaweed in 2011, and the blob has grown every year since then.
On the water, the Sargassum provides shelter and breeding grounds for some marine life, including fish, crab and sea turtles. When it lands as a mat on shore, however, it begins to rot, emitting fumes of ammonia and hydrogen sulfide that smell like rotting eggs. It also can irritate eyes, ears and throats of human beings.
In Key West, officials are reporting a heavier amount of Sargassum so far this year than ever, while in Mexico it has choked beaches south of Cancún. Last year, the blob was so bad that the U.S. Virgin Islands declared a state of emergency, and algae clogged the desalination plant in St. Croix.
For the tourist industry, Dr. Lapointe says, “It’s having catastrophic effects.”
See the video below from a tourist in Mexico:
