A record amount of algae is choking the caribbean shoresfrom Puerto Rico to Barbados, with tons of brown sargassum that kill wildlifeaffect tourism and release toxic gases.
More than 24 million tons of sargassum blackened the Atlantic in June, compared to 18.8 million tons in May, according to a monthly report from the Optical Oceanography Lab at the University of Florida, which described that figure as “a historical record”.
And in July the presence of algae in the Caribbean Sea did not decrease, according to Chuanmin Hu, a professor of optical oceanography who collaborates on these reports.
“I was scared,” Hu said, recalling how he felt when he saw the June statistics. He said they were 20% higher than the previous record set in May 2018.
Hu compiled more information for the Associated Press agency, according to which the accumulation of sargassum in the Eastern Caribbean reached near-record levels this yearsurpassed only by those of july 2018. Algae levels in the northern Caribbean are the third highest ever recorded, lower only than in July 2018 and the same month in 2021.
Scientists say the reasons why sargassum levels are so high need further investigation, although the United Nations Caribbean Environment Program says possible factors include a increase in water temperature as a result of climate change, as well as nitrogen filled fertilizers Y sewage water that feed the reproduction of sargassum.
“This year was the worst that we have on record,” said Lisa Krimsky, a researcher at the University of Florida. very devastating for the region”.
He added that large masses of sargassum have a strong environmental impactas decomposing algae alter water temperature and pH balance, as well as reduce populations of seagrasses, coral reefs, and sponges.
“Basically, they are being suffocated,” Krimsky said.
It also affects humans
In some places in the eastern Caribbean, the concentration of algae is so strong that the French island of Guadeloupe issued an alert at the end of July. He noted that there were communities where large masses of decomposing algae released hydrogen sulfide, which can affect people with respiratory problemsincluding asthmatics.
The US government declared a federal emergency after US Virgin Islands reported “unusually high amounts” of sargassum last month affecting water production at a desalination plant near St. Croix, which is struggling to meet demand amid a drought.
“We consume everything we can produce,” said Daryl Jaschen, director of the islands’ emergency management office. “This worries us a lot.”
The US Virgin Islands power plant, on the other hand, uses ultrapure water from the desalination plant to reduce emissions monitored by the US Environmental Protection Agency. The loss of that water would force the government to use a type of diesel fuel that is more expensive and scarce, officials said.
A problem that was born in 2011
Experts first noted an increase in the amount of sargassum in the Caribbean Sea in 2011, which Hu and other scientists believe was caused by stronger-than-normal winds and currents. The problem was aggravated by the multiplication of large masses of algae, in a process driven by nutrients and strong winds. “In the tropical Atlantic, everything was favorable,” Hu said. “Everything grows fast.”
Moderate amounts of sargassum help They purify water, absorb carbon dioxide, and are a key part of the habitat of fish, turtles, shrimp, crabs, and other creatures. But they are not good for tourism, the economy and the environment if they accumulate too close to coasts or on beaches.
A carpet of brown algae recently surrounded an uninhabited island off the French territory of Saint Marten popular with tourists, forcing authorities to suspend a ferry service and cancel kayaking and diving excursions. The normally translucent waters of Pinel Island they took on a brownish hue.
“It’s the worst we’ve seen around here, without a doubt,” said Melody Rouveure, manager of a company that organizes tours on the Dutch part of the island, Sint Maarten. “It messed up my plans for the beach.”
On Union Island, which is part of Saint Vincent and the Grenadines, algae invasion forced some hotels to close for up to five months in the past.
The masses of sargassum also hit the fishing industry. They damage boat engines and fishing gear, prevent fishermen from reaching their boats and fishing grounds, and reduce fish catches. Barbados was among the hardest hit, with flying fish accounting for up to 60% of its annual catch, according to the University of the West Indies.
It was attributed to an excess of sargassum recent death of thousands of fish on the French island of Martinique. Activists are also concerned about endangered turtlessome of which die when they get entangled in the algae or cannot lay their eggs in the sand because it is covered with sargassum.
In the Cayman Islands, a thick carpet of sargassum prompted the government to experiment with a program that cleaned 268 square meters of algae. On Tuesday, however, the government said suspended the program because the level of decomposition of the algae made it impractical.
“Sargassum in the North Sound area is something we’ve never seen before because of its location, climatic conditions and its scale,” authorities said.
Other islands decided use heavy machinery to remove sargassum from beaches, but scientists say that causes erosion and can destroy the nests of endangered turtles.
How to use sargassum
Given this situation, efforts continue to use sargassum as fertilizer, food, biofuel, construction material or medicinal products, but several Caribbean nations cannot remove large amounts of algae because they face financial problems and have limited resources.
US Virgin Islands Governor Albert Bryan asked President Joe Biden to declare a federal emergency on all three of its islands, not just St. Croix, but that didn’t happen. Bryan said that he now tries to raise funds on the islands themselves to clean up the beaches. “But we need money for a lot of things right now,” he said.
Since 2011, large amounts of sargassum have invaded the Caribbean every year except 2013, an anomaly that scientists attribute to a nutrient shortage and a change in the strength and direction of the winds. The large quantities recorded in recent years raise the concerns of scientists and authorities.
“We don’t know if this has become the norm,” Krimsky said. “But it has been something devastating for over a decade”.