Get Ready for an Awful Season of Seaweed

FLORIDA – As if the late-season red tide bloom that continues to plague Florida beaches well into winter were not bad enough, scientists say that we are in for a similarly awful seaweed season as a bloom twice the size of the contiguous United States makes its way toward Florida’s Gulf Coast.

The 5,000-mile-wide seaweed bloom known as the Great Atlantic Sargassum Belt stretches from West Africa to the Gulf of Mexico and impacts Florida beaches each spring, usually around May. Satellite imagery suggests that this year's bloom could be the largest in history.

"It’s incredible," Brian LaPointe, a research professor at Florida Atlantic University’s Harbor Branch Oceanographic Institute, recently told NBC. "What we’re seeing in the satellite imagery does not bode well for a clean beach year."

Some Key West beaches are already starting to see signs of the algae. In deeper waters, the giant mat of seaweed is eco-friendly, providing habitat for marine life while absorbing carbon dioxide. When it hits the shore, however, it can become destructive to the local ecology, and the more that washes up, the worse the impact, which is why this year's bloom is of particular concern to coastal communities whose economies rely on tourism.

Most Florida beachgoers are familiar with the occasional beach outing spoiled by massive mounds of malodorous seaweed piled in the sand and cooking under the Florida sun. It seems as though we are likely to be in for more of those days than usual this year, and the fact that we are experiencing a longer-than-usual red tide season could make for a devastating one-two punch to coastal economies.

Scientists say that the phenomenon has been increasing steadily and that in 2011, the giant mass became visible from space for the first time. Blooms in 2018 and 2022 have been the largest ever recorded, while this year's bloom seems poised to set a new high.

There are many factors that can contribute to the phenomenon, according to LaPointe, who told NBC News, "You have the Congo, the Amazon, the Orinoco, the Mississippi – the largest rivers on the planet, which have been affected by things like deforestation, increasing fertilizer use and burning biomass. All of that is increasing the nitrogen concentrations in these rivers and so we’re now seeing these blooms as kind of a manifestation of the changing nutrient cycles on our planet."