After 13 Years, No End In Sight For Caribbean Sargassum Invasion; Toxic Air, Buried Beaches, Clogged Rivers

Schools evacuated due to toxic gas. Smelly tap water at home. Tourist operators and fishers struggling to stay in business. Job losses. Power outages affecting tens of thousands of people at a time. Dangerous health problems. Even lives lost. uch crises were some of the consequences of sargassum in the islands of the Caribbean in 2023, and they have become common in the region since 2011 when massive blooms began inundating the shorelines in the spring and summer months.

On April 18, 2023 in Guadeloupe, the air-quality monitoring agency Gwad’Air advised vulnerable people to leave some areas because of toxic levels of gas produced by sargassum. Six weeks later, about 600 miles to the northwest, sargassum blocked an intake pipe at an electricity plant at Punta Catalina in the Dominican Republic. One of the facility’s units was forced to temporarily shut down, and a 20-year-old diver named Elías Poling later drowned while trying to fix the problem. In Jamaica, during the months of July and August, fishers found themselves struggling through one more season as floating sargassum blocked their small boats and diminished their catch. “Sometimes, the boats can’t even come into the creek,” said Jamaican fisherman Richard Osbourne. “It blocks the whole channel.” In the British Virgin Islands (BVI), most of Virgin Gorda’s 4,000 residents had to deal with sporadic water shutoffs and odorous tap water for weeks after sargassum was sucked into their main desalination plant last August. And in Puerto Rico, a highly unusual late-season influx inundated the beaches of the Aguadilla area for the first time, leaving residents like Christian Natal and many others out of work for a week when it shut down businesses including the jet ski rental company that employs him.

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Sargassum is not a bad thing in itself. Nor is it new to the Caribbean, where it has always washed ashore in modest quantities in the spring and summer, providing habitat for marine life and helping build beaches as it decays. But 2011 brought too much of a good thing. Way too much. Without warning that year, sargassum suddenly swamped shorelines. It piled several feet high on some beaches. It stank like rotten eggs as it decomposed. It shut down resorts, dealing a major blow to a tourism sector in some areas of the Caribbean still struggling to recover from the 2008-2009 global recession. It gave coastal residents headaches, nausea and respiratory problems. It disrupted turtle nesting sites and threatened reefs and mangroves.

As sargassum continued to flood the Caribbean and the western coast of Africa 8,000 miles away, scientists made a surprising discovery. Historically, most of the seasonal influx in the Caribbean had come from a two-million-square-mile gyre in the northern Atlantic Ocean: the Sargasso Sea. “The Sargasso [Sea] has been around for hundreds of thousands of years, and it’s an ecosystem that was perfect, so to speak,” said Dominican Republic oceanographer Elena Martinez. “It was there surrounded by four oceans gyres, or currents, that kept it perfect.” But scientists soon learned that most of the new Caribbean influx wasn’t coming from the Sargasso Sea anymore: It was coming from a new sargassum ecosystem that had formed in the southern Atlantic Ocean.

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https://www.dailyclimate.org/caribbean-sargassum-invasion-2667851246/the-great-atlantic-sargassum-belt