It’s been a record year for sargassum, which has hit not only the Yucatán Peninsula but also beaches from Texas to the Carolinas in the United States, as well as the Caribbean islands.
Masses of brown seaweed are clogging bays and piling up on beaches in the Gulf and Caribbean.
Sargassum is a free-floating weed that forms large mats moved by wind and ocean currents. A massive bloom is now appearing almost every year in the tropics, causing big problems where tourism and fishing are economic drivers.
In the Riviera Maya, state officials said the mats of sargassum seaweed are likely to continue washing up — in volumes never previously reached — at least until September.
Officials told The Associated Press that workers are removing an average of 1,100 cubic meters/1,439 cubic yards of sargassum per day. The seaweed is not harmful, but it often smells when it decays.
In Playa del Carmen, it started washing up in 2014, three years after other regions began noticing a problem. First thought to be a trivial matter, a general sense of alarm followed increasingly grotesque mounds washing ashore. Today, the city has a tractor that sifts the beach sand. But not every beach gets cleaned every day, reports Everything Playa del Carmen.
Beach clubs or hotels dispatch staff armed with rakes. They dig a hole on the beach, and bury it so it can break down. When they run out of places to bury it, staff cart it away.
Bad for ecosystems
In Barbados, a fisheries biologist says sargassum is a national emergency. Hazel Oxenford, of the University of the West Indies, told National Public Radio that the seaweed piles up on the shoreline 10 to 12 feet high. Even worse, she says, masses of the weed cover the water near the beaches.
“It creates tremendous problems for the natural ecosystems,” Oxenford says. “We’ve had significant loss of endangered sea turtles that have actually drowned because they can’t get to the surface because the sargassum above them is so high.”
“Sargassum had always been present in the Caribbean,” says Jim Franks, a marine biologist at the University of Southern Mississippi, “but never in such large quantities.”
Sargassum is named for the Sargasso Sea, an area in the Atlantic north of the Caribbean, where it was first thought to originate. Researchers later traced the seaweed to a massive bloom off the coast of Brazil.
The cause of the sargassum bloom is up for debate, but Oxenford attributes it to nutrients dumped into the ocean by farming and development worldwide.
“We’re talking about mass increase in nutrient levels from deforestation in the Amazon, from urbanization in the Congo,” she says. “Plus climate change, particularly an increase in surface water temperatures. Because the two things that plants or this floating seaweed will respond to is an increase in nutrients and an increase in water temperature.”
NASA and Texas A&M scientists have developed a website that offer forecasts of the floating mats of seaweed. On the SEAS (Sargassum Early Advisory System) home page, find the forecast section and the dropdown to “Quintana Roo North.”
It’s good to know where blooms are headed, but as with hurricanes, nothing stops them once they develop.
Sources: AP, NPR
{ Related: Sargassum can be a valuable farm resource }
