Senior News Writer
sargassum seaweed covers a beach

Sargassum seaweed in Martinique, one of the islands affected by record blooms in 2018. This year’s accumulation is forecast to be even bigger. Photo: Shutterstock

The Inertia

We knew the sargassum seaweed raft headed for Florida was big, but new observations suggest that by the time it arrives in the coming months, it could be the biggest ever to hit the state.

Researchers with the University of South Florida are tracking the encroaching bloom. From west Africa to the Gulf of Mexico, the team’s mapping technology shows there’s more seaweed than ever in the so-called Great Atlantic Sargassum Belt.

How much? About 13-million tons of it, the team estimates. That’s a “record abundance” for this time of year, and peak seaweed season doesn’t usually occur until June. And in short, it means Floridians and Caribbean dwellers are in for a sloppy summer.

“Major beaching events are inevitable around the Caribbean, along the ocean side of [the] Florida Keys and east coast of Florida, although the exact timings and locations are difficult to predict,” the team’s report said.

Sargassum is a genus of brown seaweed that flourishes in temperate and tropical oceans around the world. As it clumps and accumulates, floating islands of it can grow to miles wide — in this case, around 5,000 miles across. That’s wider than the United States.

As the weed complex rides prevailing currents westward, it will act as a habitat and food source for birds, fish, sea turtles, and crustaceans.

Then it will engulf the Sunshine State and surrounding areas. And when that happens, a general gross-out will ensue.

As it stagnates on the sand, the algae will rot and release chemicals like hydrogen sulfide gas, which smells like rotten eggs. When inhaled, the gas can also cause headaches and irritate the mucous membranes — people with asthma or other breathing problems may experience increased sensitivity to its effects, according to the Florida Department of Health.

Florida Atlantic University oceanographer Brian Lapointe told Scientific American that 2018 was the record year for the Great Atlantic Sargassum Belt. In the same interview, he said “[t]his is the new normal, and we’re going to have to adapt to it.”

As The Inertia reported in a previous seaweed blob story, those adaptations could prove critical to preserving coastal infrastructure. And even though the “blob” is a huge floating habitat itself, it can smother existing beach ecosystems where it washes up.

Dr. Chuanmin Hu and the University of South Florida oceanography team promised to keep monitoring this year’s seaweed flotilla in their recent update. The team plans to publish its next report before the end of April.

In the meantime, you can watch the blob yourself in “near real-time” on the Sargassum Watch System’s website.


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