Huge mats of seaweed washing up on some of Cayman’s beaches and floating near shore are presenting major challenges for beachgoers, boaters and fishermen.
Cayman is not the only island in the Caribbean being impacted by this tangled mess of seaweed. It is an issue on coasts throughout the entire region, according to the Gulf and Caribbean Fisheries Institute.
“There have been a lot of questions about the volume of sargassum [seaweed] this year and the past few years as compared to the past,” said Billy Causey, regional director, National Oceanic and Atmospheric Administration office of National Marine Sanctuaries.
“What we have been told is that the sargassum is not the same species as what we find in the Sargasso Sea and the blooms seem to be originating off South America in the vicinity of Venezuela,” said Mr. Causey. “Some attribute the blooms to the warm waters we are having and others point to the nutrients from runoff.
“I suspect it is a combination of both and other environmental factors.”
He said those who promote beaches for tourism don’t care for the rafts of sargassum, but it is a natural process that serves an important biological and ecological function both off- and on-shore.
The Sargasso Sea is located within the Atlantic Ocean and is the only sea without a land boundary. Mats of free-floating sargassum, a common seaweed found there, provide shelter and habitat for marine life.
According to the Cayman Islands Department of Environment, anyone finding the seaweed washing up on their beaches should either step over it or rake it up, disposing of it. for example, as plant fertilizer. The department asks people to avoid the use of a backhoe because it can lead to problems for turtles. It is currently turtle nesting season, when turtles come ashore to dig nests and lay eggs. The brown sargassum seaweed stands out on Cayman’s white sandy beaches after it has dried out.
In East End, one resident said a pile of seaweed is so high she could not see the sea from her house. In Bodden Town, visitors to Coe Wood Beach are finding it a nuisance.
“When will it ever end?” asked one fisherman, as he cast his line only to quickly haul in a catch of seaweed.
However, visitors to Seven Mile Beach, one of Cayman’s most popular beaches, have not reported a major issue with the seaweed this year.
While it may be a bane for fishermen and swimmers, sargassum seaweed provides a home to a variety of marine species. Turtles use sargassum mats as nurseries, where hatchlings have food and shelter. It also provides an essential habitat for marine species such as shrimp, crab and fish, that have adapted specifically to this floating environment.
“It’s just a natural occurrence that happens every once in awhile,” said Captain Paul Hurlston. When he was a child, he said there would be huge mats of seaweed floating around the island, especially during southerly winds.
“In fact, when we were fishing and towing in the catboats for queen fish, the seaweed would get caught up in the tow lines,” Mr. Hurlston said. “It’s nothing new. Lots of people used it as fertilizer, some even say it has lots of iodine. But this year, I must say, it is a lot,”
Billy Adam said the seaweed can be used as a fertilizer. “Some years ago,” he said, “instead of carting it off to the dump, a contractor sold it to different farmers and they used it on their plants.
“It’s very good and the reason why it’s so good is the elements on the periodic table … Seawater has about 90 of the 92 basic elements that make up everything on Earth. The seaweed in itself has agar, which is used at the hospital when they take a blood sample. The substance in the petri dish that they put the sample in is agar. It is good for growing bacteria.”