When will sargassum – the smelly, brown seaweed blob – hit Florida beaches in 2024?
Many in South Florida are probably already looking ahead to spring break and thinking about making more frequent trips to the beach.
But like clockwork during the warmer months, many beachgoers encounter an accustomed nuisance on our shores: a massive, smelly blob of brown seaweed.
It’s called sargassum, and scientists say the blob is growing and already making its way to Florida.
What is sargassum?
Sargassum seaweed is a brown macroalgae that can be found floating on the ocean surface and consists primarily of two species, S. natans and S. fluitans. According to the Univesity of South Florida’s satellite-based Sargassum Watch System (SWS), it provides food, shade and shelter to fish, crabs and turtles. It may also serve as fertilizers for sand dunes, protects shoreline stability, and is a marine resource for biomass for food, fuel, and as a possible resource of pharmaceutical materials.
Sargassum is made of up a variety of leafy appendages, but round, berry-like structures called pneumatocysts that are filled with oxygen are what allow it to float to the surface, according to the National Oceanic and Atmospheric Administration.
Not only is the seaweed abundant in the Atlantic, but it’s also found in the Gulf of Mexico, the Caribbean Sea and even along the coasts of the British Isles and mainland Europe.
Why can sargassum be problematic?
When these clusters of Sargassum make their way to the shoreline, it can create an unpleasant experience for beachgoers.
When sargassum decomposes on beaches, it not only smells bad, but it attracts insects and can cause many environmental problems such as fish kills and smothering turtle nesting sites, according to the SWS.
Where is the sargassum bloom now?
During January of this year, 5.5 million metric tons were detected in the central Atlantic — a slight increase from what was observed in December 2023, scientists wrote in a monthly bulletin for the SWS.
“Even though this increase is less robust than the change from November to December, the current Sargassum abundance remains quite high for the month of January – only surpassed by the quantities in January 2018 and January 2023,” scientists wrote.
The largest aggregations of the sargassum are in the interior central Atlantic basin and have been advancing westward for the past several months. Scientists said small portions are approaching the Lesser Antilles, larger ones are still a few hundred kilometers to the east, and short-lived clusters are offshore northeastern parts of South America.
When will Florida start seeing sargassum?
Good news for spring breakers: scientists said the southeast coast of Florida, including the Florida Keys, will be largely free of sargassum until at least late April or May.
