Seaweed overruns some Caribbean beaches as Sargassum hits record levels

FILE – Will smelly Sargassum seaweed make a comeback along Florida beaches?

We’re well into the summer season and people continue to flock to beaches to catch some rays and take a dip in the ocean. One thing people aren’t missing, however, is the smelly Sargassum seaweed that has littered beaches across the U.S., including Florida, which saw a record-breaking invasion of the Sargassum last year. FOX Weather Correspondent Brandy Campbell was in Fort Lauderdale on Wednesday and spoke to some beachgoers about their concerns.

PONCE, Puerto Rico – As Sargassum levels surge to unprecedented amounts across parts of the Atlantic basin, some beaches in the Caribbean have already been overwhelmed by the thick, smelly seaweed. 

Photos and videos taken throughout the Caribbean show extensive accumulations of the smelly algae along the southern and eastern coasts of Puerto Rico, as well as in parts of Cozumel and Mexico’s Yucatán Peninsula. 

In some locales, the buildup appeared to be so significant that residents and tourists stayed away from the shoreline entirely, leaving some beaches relatively empty.

The uneven impact of the seaweed means one area may be spared while a nearby location experiences the brunt of the activity. Much of the variation appears to be driven by ocean currents that either direct or protect the seaweed from reaching specific locations.

RECORD-BREAKING SARGASSUM INVASION IN ATLANTIC, CARIBBEAN THREATENS TO FOUL BEACH RESORTS

Ceiba, a coastal community on Puerto Rico’s eastern shore southeast of San Juan, appeared to be one of the hardest-hit areas. 

Photos taken in the coastal community showed beaches blanketed by the brown algae.

Remarkably, the beaches located less than a 20-minute drive away looked pristine, which underscores the unpredictable nature of the event. 

Unlike the photos from Ceiba, images from tourist-heavy areas along Mexico’s Yucatán coast revealed that some areas had benefited from cleanup operations, which helps to temporarily mitigate the unwanted sight.

The Mexican government previously stated it was taking a more proactive approach in 2025, dedicating resources to both monitor and manage the seaweed.

The government’s efforts appeared to be focused on protecting the region’s critical tourism industry, which can suffer when unpleasant coastal events arise.

Photos from Cancun, Mexico on June 7, 2025.

(Ayuntamiento de Benito Juárez / FOX Weather)

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While the seaweed might look unpleasant, health experts advise beachgoers that the Sargassum isn't usually harmful to humans. However, tiny creatures that bury in the globs can produce rashes and blisters if contact is made with the skin.

For some species of marine life, the brown algae are considered to be helpful, and biologists believe that the buildup provides food and refuge for small fish, crabs, shrimp and other organisms.

Monthly updates from the University of South Florida’s Optical Oceanography Lab are expected to show that the Sargassum will remain at significant levels at least through the summer.

Experts at the Tampa-based university warn that increased amounts could lead to problems along the U.S. Gulf Coast and Florida, but it remains to be seen whether volumes will rival what was experienced during the 2023 season.

Map showing Sargassum population as of May 2025.

(University of South Florida’s Optical Oceanography Lab / FOX Weather)