A Giant Destructive Blob Is Headed For Florida, And It Stinks

It's not believed to be a deadly entity from space intent on consuming everything in its path.


Rachael Funnell


Rachael Funnell

Digital Content Producer

Rachael is a writer and digital content producer at IFLScience with a Zoology degree from the University of Southampton, UK, and a nose for novelty animal stories.

Digital Content Producer

sargassum blob in florida

Swimming in Florida could be about to take a dramatic turn. Image credit: JTang/

Steel yourselves, Florida: something massive might be about to beach itself on your shores. Reports are forecasting that a gargantuan blob of sargassum seaweed has accumulated in the Atlantic Ocean and is headed for the US state, bringing with it millions of tons of odorous seaweed.

Sargassum is a genus of brown macroalgae (the fancy word for seaweed) that’s found in temperate and tropical oceans across the globe. It can form giant clumps like floating islands that stretch for miles, providing shelter and food to birds, fishes, sea turtles, and crustaceans. 


These gargantuan seaweed islands are the exclusive home for some species like sargassum fish, and act like nursery grounds for juvenile animals including mahi mahi and turtles. Eventually, these islands lose their buoyancy and sink to the seafloor where they become a primary food source in the food webs of the deep sea, so they are an important habitat for many species across different zones of the water column.

However, in recent years sargassum has become increasingly nomadic as warming ocean temperatures have seen it blossom in unfamiliar waters. It’s also thought to have experienced a boom in growth as a result of climate change and nutrient runoff from the Amazon and Mississippi. Its emigration and boom in growth means that it can sap the nutrients and oxygen out of the reefs it engulfs, and things only get worse when it makes ground.

“Golden tides” like the sea of sargassum that’s currently floating towards Florida can stink to high heaven of a potent blend of rotten eggs (thank you hydrogen sulfide gas) topped off with a salty sea tang. As it decomposes, it releases its stored carbon into the air, contributing towards the planet’s already-too-high CO2 emissions.

2022 was a record-breaking year for sargassum and 2023 may be an even bigger year, as old seaweed acts like seeding material to get the next crop off to a bumper start. Mangroves, docks and canals are particularly affected by sargassum as they provide a place for it to bottleneck, creating dead zones in which other life can’t thrive.


According to Southern Living, the vast stretch of sargassum currently dominating the Atlantic Ocean has doubled for two months consecutively, now sitting at around 8.7 million tons. That’s roughly 3,000 Olympic-size swimming pools for context, and makes for a frightening day at the beach.

“Our beach could literally be clean at 8 a.m. and three to four hours later a giant mat of sargassum the size of a mall will come in like the blob, like a Stephen King movie,” Tom Mahady, city of Boynton Beach (Florida) Ocean Rescue chief, told USA Today. "It's not pleasant for swimmers."

Elsewhere in the world, scientists have got to work trying to develop sustainable ways to tackle golden tides. The goal is to find an effective way to pre-process seaweed piling up on beaches so it can be turned into something useful.

“It’s free and there’s so much of it, so it makes sense to convert it into useful products. But converting marine biomass like seaweed usually requires removing it from salt water, washing it in fresh water and drying it,” said Professor Mike Allen of the University of Exeter and Plymouth Marine Laboratory, who’s leading the processing project, to The Guardian. “That’s very expensive, so we needed to find a method that would be both economically and environmentally viable.”


Keep a weather eye on the horizon, Florida. Something stinky this way comes.


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  • ocean,

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  • florida,

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  • marine,

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  • sargassum