(CNN) A gigantic mass of algae that has formed in the Atlantic Ocean is heading towards the shores of Florida and other shores throughout the Gulf of Mexico, threatening to dump fetid and potentially dangerous heaps on the beaches and put a major damper on the tourist season .
The kelp, a species called sargassum, has long formed large blooms in the Atlantic, and scientists have been tracking massive accumulations since 2011. But this year’s Sargassum mass could be the largest on record – stretching more than 5,000 miles from the coast of Africa to the Gulf of Mexico.
The blob is currently pushing west and will migrate through the Caribbean and as far as the Gulf of Mexico in the summer, with the algae, according to Dr. Brian Lapointe, a researcher at Florida Atlantic University’s Harbor Branch Oceanographic Institute, is expected to be widespread on Florida beaches in July.
Lapointe said this year’s sargassum blooms started forming early, doubling between December and January. The crowd “was larger in January than at any time since this new region of Sargassum growth began in 2011,” Lapointe told CNN’s Rosemary Church.
“This is an entirely new oceanographic phenomenon that is creating such a problem — truly a catastrophic problem — for tourism in the Caribbean region, where it’s piling up on beaches as deep as 5 or 6 feet,” Lapointe added.
He noted that Barbados locals “use 1,600 dump trucks a day to clean the beaches of this seaweed to make it suitable for tourists and beach recreation.”
What is sargassum
Sargassum is a collective term that can be used to refer to more than 300 species of brown algae, although Sargassum is natans and Sargassum is fluitans the two most common species in the Atlantic.
The algae have their advantages when floating at sea.
“This floating habitat provides food and shelter for fish, mammals, seabirds, crabs and more,” according to the website of the Sargassum Information Hub, a collaborative project of various research institutions. “It serves as a critical habitat for endangered loggerhead turtles and a nursery for a variety of commercially important fish such as mahi mahi, jacks and amberjacks.”
The problems arise when Sargassum hits the beaches, not only piling up into hills that are physically difficult to navigate, but also releasing a gas that can smell like rotten eggs. And it can quickly go from being an asset to a threat to ocean life.
“It’s coming in in such large quantities that it’s basically sucking the oxygen out of the water and creating what we call dead zones,” Lapointe said. “These are typically fishing habitats … and once they’re deoxygenated, we’ve lost that habitat.”
Sargassum can also be hazardous to human health, Lapointe noted. The gas released by the decaying algae, hydrogen sulfide, is toxic and can cause breathing problems.
“You have to be very careful when cleaning the beaches,” he warned.
The seaweed itself also contains arsenic in its flesh, making it dangerous when ingested or used as fertilizer.
“If you’re somewhere where you’re harvesting this to use as a fertilizer … you have to be very concerned, especially if you’re using it on a food and fiber crop for human consumption,” Lapointe told CNN on Thursday.
Cleaning up seaweed piles on beaches costs millions of dollars, the Sargassum Information Hub notes.
Why 2023 has a sargassum problem
Just like plants and crops on the ground, the spread of seaweed may shift from year to year depending on ecological factors influenced by changes in nutrients, precipitation and wind conditions, said dr Gustavo Jorge Goni, oceanographer at the Atlantic Oceanographic and Meteorological Laboratory of the National Oceanic and Atmospheric Administration.
Likewise, ocean currents can alter sargassum’s annual growth and how much accumulates, Goni added. Phosphorus and nitrogen in the sea can also serve as food for the algae.
After sampling the area where sargassum formed and comparing it to old samples from the 1980s, Lapointe found that nitrogen levels had increased by 45%. Researchers believe the increase is a likely cause of the flower’s massive growth.
These elements can be released into the ocean from rivers that receive concentrations of phosphorus and nitrogen from human activities such as agriculture and fossil fuel production, according to the Environmental Protection Agency.
Right now, researchers are looking at ways to thwart its impact on beaches, possibly by sinking the seaweed to the bottom of the ocean or harvesting it for use in commercial products like soap, Goni said.
Goni also warns that research into these sargassum clusters is new, and it’s likely that scientists’ understanding of how the algae grow will change over time.
“What we believe, we know today, it may change tomorrow,” he said.
Taylor Nicoli contributed to this story.