Largest ever mass of Sargassum seaweed drifts toward North America

Largest ever mass of Sargassum seaweed drifts toward North America
When the Sargassum mat washes ashore, it becomes a decaying mass that smells of rotten eggs
When the Sargassum mat washes ashore, it becomes a decaying mass that smells of rotten eggs
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A clump of Sargassum
A clump of Sargassum
Infrared satellite image showing Sargassum mats in red
Infrared satellite image showing Sargassum mats in red
When the Sargassum mat washes ashore, it becomes a decaying mass that smells of rotten eggs
When the Sargassum mat washes ashore, it becomes a decaying mass that smells of rotten eggs
View gallery - 3 images

ESA's Sentinel-2 satellite is tracking what may be the largest bloom of Sargassum seaweed ever recorded as it drifts toward the US East Coast, threatening to dump millions of tons of rotting vegetation on thousands of miles of beaches.

Famed in history and folklore, the Sargasso Sea is what at first seems to be a legend, but turns out to be a solid fact. First recorded in the logs of Christopher Columbus, who sailed through it in 1492, it's a huge calm patch in the middle of the Atlantic Ocean where the great sea currents flow around it, but not through. It's located in the doldrums latitudes where the winds may not blow for weeks at a time, leaving behind thousands of square miles of unmoving deep-blue water of remarkable clarity.

But what makes the Sargasso Sea worthy of raising the hairs on the back of the neck is the Sargassum weed that grows there. It's a form of rootless, leafy algae with grape-like bladders that keep it afloat. It turns the Sargasso Sea into a matted jungle where seahorses live and acts as the mating ground for the European and American eels, which was a mystery for thousands of years.

A clump of Sargassum
A clump of Sargassum

This weed was also a fearsome sight for sailors. Columbus thought he'd be tangled in it or that it indicated shallow waters and reefs. Over the centuries, it developed a mythical reputation as a graveyard of ships where, supposedly, fleets of rotting hulls floated in the clutches of the weeds long after their stranded crews had died of hunger and thirst.

It also inspired many works of fiction, including a Doc Savage novel, the works of Dennis Wheatley and Ezra Pound, and even an episode of the Jonny Quest cartoon series.

Today, the Sargassum poses a more realistic problem. As part of ESA’s Earth Observation Science for Society initiative. Sentinel-2, 3, and 6 have been monitoring and tracking the latest Sargassum bloom recorded, which extends over 5,500 miles (8,800 km) from the shores of Africa to the Gulf of Mexico and is estimated to have a mass of 10 million tonnes.

Infrared satellite image showing Sargassum mats in red
Infrared satellite image showing Sargassum mats in red

So long as it remains in the deep ocean, the Sargassum isn't much of a problem, but as it approaches the Florida Keys, the Yucatán Peninsula, and the eastern Caribbean, it could have a nasty impact. In shallow water, the Sargassum could reduce oxygen in the water to critical levels and disrupt fishing and the local ecology. Washing onto the beaches, it would soon rot in the tropical sun, emitting toxic hydrogen sulfide gas and the nauseating odor of rotten eggs.

The result could be economic damage in the millions, so ESA and other agencies are keeping a close eye on the giant mat's drift. Since it will have to cross through the Gulf Stream, it could be pushed north, and exactly where it may end up is still uncertain. But one thing is certain – a lot of people will be investing in nets to keep it off beaches, and rakes, pitchforks and power equipment to clear it away if it makes landfall.

Source: ESA

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Brian Beban
Can it be used for fertilizer ? Or to stop cows farting as seaweed has been shown to do.
Maybe this can be harvested to make biogas.
David F
As @Brian and @Kai have alluded, it is odd that landfall of thousands of tonnes of free, easily harvested, biomass is not welcomed as nature's bounty.
Rick O
Of course this should be used for biogas and/or fertilizer, and hopefully when it reaches land it's used for that. But since most sewer authorities don't take advantage of all the methane they have access too, I won't be surprised if this all just ends up in landfill. If it does, with any luck it'll be a place that collects the methane from the trash mounds for powering garbage trucks, etc.
Norm Ness

You have omitted to include a MAJOR conclusion and a related fact!!!!
HOW long has this been tracked????
WHEN is it predicted to arrive at the western Atlantic shores???
1 year?....1 decade?.....1 century?....
Isn't this seaweed pulling huge quantities of CO2 from the ocean/atmosphere as it grows? Another story suggested drying biomass and salting it to keep bacterial decomposition. Don't see why you couldn't sun dry the seaweed and bury it mixed with salt. https://newatlas.com/environment/crops-carbon-sequestrations-climate-crisis/
Don Rathburn
Somebody ask Elon Musk and the chat GPT bots what we should do with it. Will any birds, fish, or other animals eat it ? Years ago a friend in Georgia told me a story about kudzu, which has absolutely devastated the south. He said the plant was brought to the US to be used as feed for cattle. It was being tested in a lab, but then escaped. It was said that cattle did not like the taste of it and would not touch it. I don't know if any parts of the story are true, but it makes a good fiasco/disaster/ tragedy/ bad judgement legend.
When I was a kid on the westcoast of Sweden, we had occasions after storms with large masses of beached seeweed. Local farmers loved it as fertilizers. I can still remember the distinct smell of the seaweed.

See the seaweed as a possibility NOT a problem.
I read some article through the Seasteading Institute that mentioned a company in Vancouver, BC was compressing seaweed into building blocks that connect together too make building blocks. I think they float; talked about building structures at sea. If they can remove the sulfur to use for batteries, that would be useful. Sculpt buildings with sargassum mache.
Craig Sharp
Fertilizer: Sargassum seaweed is rich in nutrients such as nitrogen, phosphorus, and potassium, which make it an excellent fertilizer for crops and gardens.

Food: Sargassum seaweed is edible and is used in various dishes in Asian and Caribbean cuisines.

Cosmetics: Sargassum seaweed is used in skincare and cosmetic products due to its anti-inflammatory and anti-aging properties.

Biofuel: Sargassum seaweed can be converted into biofuel as it has a high content of carbohydrates.

Animal feed: Sargassum seaweed can be used as animal feed for livestock and fish.

Soil erosion prevention: Sargassum seaweed can be used to prevent soil erosion by acting as a natural barrier against waves and tides.

Water filtration: Sargassum seaweed can help in water filtration by removing excess nutrients and pollutants from the water.

Overall, sargassum seaweed has several potential uses in various fields, including agriculture, food, cosmetics, and environmental conservation.

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