There was no decline in algae in the Caribbean Sea in July, said Chuanmin Hu, an optical oceanography professor who helps draft the reports.
“I was scared,” he recalls the feeling when he saw the historic figure for June. He noted that it was 20% higher than the previous record set in May 2018.
Hu collected additional data for The Associated Press that showed sargassum levels for the eastern Caribbean near record highs this year, second only to levels reported in July 2018. Levels in the northern Caribbean are at their third highest, after July 2018 and July 2021, he said.
Scientists say more research is needed to determine why the region’s sargassum levels are reaching new highs, but the United Nations’ Caribbean Environment Program says possible factors could be a rise in water temperature from climate change and nitrogen-laden fertilizers and fertilizers. are sewage. encourage algal blooms.
“This year was the worst year on record,” said Lisa Krimsky, a researcher and faculty member with Florida Sea Grant and a regional water resource specialist at the University of Florida. “It’s absolutely devastating to the region.”
She said large amounts of seaweed have a serious impact on the environment, with decaying algae altering water temperature and pH balance and leading to declines in seagrass, coral reef and sponge populations.
“They’re essentially being suffocated,” Krimsky said.
The “golden tide” has also hit humans hard.
The concentration of algae is so high in some parts of the eastern Caribbean that the French island of Guadeloupe issued a health warning in late July. It warned some communities about high levels of hydrogen sulfide from huge rotting clumps of seaweed, which can affect people with respiratory problems, including asthma.
The Biden administration has declared a federal emergency after the U.S. Virgin Islands last month warned of “unusually large amounts” of sargassum affecting water production at a desalination plant near St. Croix struggling to meet demand during a drought.
“We are currently consuming as much as we can produce,” said Daryl Jaschen, director of the islands’ disaster response agency. “We are very concerned about that.”
In addition, the U.S. Virgin Islands power plant relies on ultra-pure water from the desalination plant to reduce emissions monitored by the U.S. Environmental Protection Agency. The loss of such water would force the government to use a type of diesel fuel that is more expensive and scarcer, officials said.
Experts first noticed large amounts of sargassum in the Caribbean Sea in 2011, which Hu and other scientists believe were created by stronger-than-normal wind and currents. The problem has worsened as the clumps multiplied, nourished by nutrients and strong sunlight.
“In the tropical Atlantic, everything just clicked,” Hu said. “Everything is growing fast.”
In moderation, Sargassum helps purify water, absorb carbon dioxide and is an important habitat for fish, turtles, shrimp, crabs and other creatures. But it is bad for tourism, the economy and the environment if too much accumulates just off the coast or on the beach.
A carpet of brown algae recently surrounded an uninhabited island near the French-Caribbean territory of St. Martin that is popular with tourists, forcing officials to suspend ferry service and cancel kayaking and snorkeling trips. The normally translucent water around Pinel Island turned to a spiky brown mud.
“This is definitely the worst we’ve ever seen,” said Melody Rouveure, general manager of a tour company in the Dutch Caribbean territory of St. Maarten, which shares an island with St. Martin. “It ruined my personal beach plans.”
On Union Island, which is part of St. Vincent and the Grenadines, the seaweed invasion has forced some resorts to close for up to five months in the past.
Masses of sargassum have also strangled the fishing industry in the Caribbean. It damages boat engines and fishing gear, prevents fishermen from reaching their boats and fishing areas and leads to a decrease in the number of fish caught. Barbados has been hit particularly hard since flying fish make up 60% of the island’s annual catch, according to the University of the West Indies.
An abundance of sargassum has been blamed for the recent deaths of thousands of fish on the French Caribbean island of Martinique. It also has activists concerned about the plight of endangered turtles, some of which die at sea, entangled in seaweed or unable to lay their eggs because of the algae mat covering the sand.
In the Cayman Islands, a thick carpet of sargassum had prompted officials to start a pilot program in which crews pumped more than 268 square feet of seaweed from the water. But on Tuesday, the government announced it was suspending removal efforts because the level of decomposition made it impractical.
“The sargassum stranding in the North Sound is unlike anything we’ve experienced before in terms of location, weather conditions and scale,” officials said.
Other island states have chosen to use heavy machinery to remove seaweed from beaches, but scientists warn that this causes erosion and could destroy the nests of endangered turtles.
Efforts to use sargassum as fertilizer, food, biofuel, building material or medicine continue, but many Caribbean islands are unable to remove the vast amounts of seaweed due to financial difficulties and limited resources.
US Virgin Islands Governor Albert Bryan said he had asked President Joe Biden to declare a federal emergency for the entire three-island area, not just St. Croix, but it didn’t. Bryan said he is now trying to find local funds to clean up beaches, “but a lot of things now require money.”
Large amounts of sargassum have invaded the Caribbean every year since 2011, except in 2013 — an anomaly that scientists believe may be the result of a lack of nutrients and a change in wind strength and direction. And the record amounts reported in recent years are even more worrisome for scientists and island governments.
“We don’t know if this is a new normal,” Krimsky said. “This has been devastating for over a decade.”