In what has become an unwelcome annual event, mats of sargassum again are bobbing off the coast of Cayman and blanketing local beaches and seafronts.
According to a report by the University of South Florida Optical Oceanography Lab, using satellite images from the NASA space agency, the amount of sargassum increased across the Caribbean Sea and the central west Atlantic in recent months.
The images show the total sargassum amount increased from 10.1 million tons in March to 10.6 million tons last month, over an area of 644 square miles. Between 2011 and 2018, the historical mean of coverage was about 31 square miles.
The April 2021 bloom was the second-largest amount recorded for that month. The largest amount in April was in 2018, when 12.6 million tons were recorded.
Looking ahead, both the eastern and western Caribbean Sea are likely to experience increasing amounts of sargassum from May to July, the latest report stated. The Gulf of Mexico is expected to see more of the seaweed being transported from the Caribbean Sea well into the summer months, with the overall bloom intensity likely to be higher than in 2019.
The overall bloom extent in 2019 was significantly higher than most of the years from 2011-2018 for the Caribbean and the central west Atlantic, according to the researchers, who stated that the reasons behind this record-high bloom and the strong decrease since September 2019 are yet to be determined.
In 2020, the numbers dropped compared to 2019, at 4.3 million tons in March and 5.8 millions tons in April.
Sargassum is a type of free-floating seaweed which can reproduce on the high seas. The Sargasso Sea, in the middle of the Atlantic Ocean, near Bermuda, was named in the early 15th century after the seaweed that is commonly found there.
While it is considered a seasonal nuisance in beaches across the Caribbean, the floating mats of seaweed are home to an array of marine creatures, including turtle hatchlings, crabs, shrimp and fish.