Holiday crowds at Martin Beach spent Memorial Day weekend dodging heaps of seaweed instead of waves, as thick mats of brown sargassum rolled ashore, piled up along the high-tide line, and sent a strong, rotten shoreline smell drifting over the sand. Photos and on-the-ground reports showed the seaweed stretching in solid bands from the dry beach right into the surf.
Where the Seaweed Comes From
Sargassum is a free-floating brown algae that scientists say formed a new belt in the tropical Atlantic after 2011 and now drifts toward Florida on ocean currents, building seasonal mats that occasionally wash up on beaches, according to the University of South Florida. A recent SaWS bulletin from the university found record-high amounts in April and warns that 2026 could be another major, possibly record, sargassum year, with beaching events likely to ramp up through the summer.
Martin County’s Messy Holiday
Locally, lifeguards and beachgoers reported dense mats blanketing Martin County shorelines and piling above the tide line. “It’s a lot out here, more than I’ve seen in a while,” one visitor told reporters, while Capt. Derick Brown of Martin County Ocean Rescue cautioned that sargassum can rub against the skin and cause rashes, as reported by WPTV.
Why This Season Looks Worse
Satellite monitoring and risk maps show large swaths of sargassum across the tropical Atlantic and Caribbean, and NOAA’s experimental Sargassum Inundation Risk product highlights southeast Florida as vulnerable to beaching in the coming weeks, according to NOAA. Local reporting and analysis also point to mounting cleanup costs, with the Miami Herald noting that Miami-Dade spends nearly $4 million a year raking and hauling sargassum, and researchers warning the scale this year could be worse…