Sargassum problem spreads

The Cayman Islands is not the only place in the region suffering from the scourge of sargassum. The problem is concentrated on North Side but a record amount of seaweed is smothering Caribbean coasts from Puerto Rico to Barbados as tons of the brown algae kill wildlife, choke the tourism industry and release toxic gases.

More than 24 million tons of sargassum blanketed the Atlantic in June, up from 18.8 million tons in May. July saw no decrease of algae in the Caribbean Sea, said Chuanmin Hu, an optical oceanography professor who helps produce reports. “I was scared,” he recalled feeling over the historic number for June. He noted it was 20 percent higher than the previous record set in May 2018.

Sargassum levels for the Eastern Caribbean are at a near record high this year, second only to those reported in July 2018. Levels in the northern Caribbean are at their third highest, following July 2018 and July 2021.

Scientists say more research is needed to determine why sargassum levels in the region are reaching new highs, but the United Nations’ Caribbean Environment Program says possible factors include a rise in water temperatures as a result of climate change and nitrogen-laden fertilisers and sewage waste fuelling algae blooms.

“This year has been the worst year on record,” said Lisa Krimsky, a researcher and faculty member with Florida Sea Grant and a water resources regional specialised agent at University of Florida. “It is absolutely devastating for the region.”

She said large masses of seaweed have a severe environmental impact, with decaying algae altering water temperatures and the pH balance as well as leading to declines in seagrass, coral reef and sponge populations.

“They’re essentially being smothered out,” Krimsky said.

The horrible trend has also has hit humans hard. As the sargassum washes up on shores, it begins to rot, releasing noxious gases such as hydrogen sulphide gas, which smells like rotten eggs. The CDC warns that hydrogen sulphide gas exposure can cause irritation to the eyes and respiratory system.

Some countries – like the Cayman Islands - have tried using heavy machinery to remove the problem from beaches, but scientists warn that this can destroy sea turtle nests and cause erosion. It’s also an expensive and totally efficient method.

Larger than normal amounts of sargassum in the region were first noticed in 2011, and it has become a recurring problem annually. Aside from the impacts on local wildlife and risks to human health, the sargassum boom has also hit local economies that make money from tourism this time of year.

The concentration of algae is so heavy in some parts of the Eastern Caribbean that Guadeloupe issued a health alert in last month.

The Biden administration declared a federal emergency after the US Virgin Islands warned last month of “unusually high amounts” of sargassum affecting water production at a desalination plant near St. Croix that is struggling to meet demand amid a drought. It is also ruining the flying fish industry in Barbados.