Video above: Sargassum is booming – this is the science behind Bloom (2023 report)
TAMPA, Fla. (WFLA) — Researchers at the University of South Florida said the amount of Sargassum Seaweed passing through the Atlantic and Caribbean in April reached record levels in April.
The university’s Optical Ocean Research Institute uses satellite data to track Salgassum, drifting off large mats between Africa’s Atlantic and Gulf coasts, sometimes washing out large amounts of Florida beaches, and stinking off foul when decomposed.
Sargassum is booming: this is the science behind Bloom
Thick blankets from Sargassum provide habitat for marine life, but can wreak havoc when winds push on land. In addition to chasing off beach fans, it can prevent light from reaching the coral and have a negative impact on the air and water quality as it breaks down.
USF researchers predicted earlier this year that 2025 will be a “major” year for Sargassum’s abundance. According to USF researchers, the total amount in the Eastern Caribbean and Western Atlantic has reached “surprisingly high” levels. They were 200% higher than historic records in April.
The total for all regions was “40% higher than the all-time high in June 2022, and 2025 was the new record year,” the researchers wrote.
The Institute of Optical Oceans has been tracking Sargassum since 2011 when seaweed became extremely abundant and could be observed by satellites. Researchers are not convinced that the 2011 event caused it to pass the threshold, resulting from the confluence of environmental factors. Research shows that excess nutrients poured into the ocean from rivers in the Atlantic Basin burn the blooms of giant algae.
“This is what you’ll get home: whether it’s Sargassum, red tide, blue-green algae, oxygen-dead zones, dying sea grass or manatees, it’s all related to an endless stream of nutrient contamination into our water. Until we fix it, algae blooms will continue to maintain blooms.
Looking ahead, USF researchers said they hope that more Sargassum will accumulate in the Caribbean and Atlantic.
“Salgassum flooding continues to occur in most of the Caribbean and the islands, as well as along the southeast coast of Florida,” the researchers wrote.
As for the Tampa Bay area, large quantities of sargassum usually do not wash the land thanks to currents. The loop current can carry seaweed from the Caribbean to the Gulf Coast north, but usually remains offshore.
