https://www.slashgear.com/2112936/africa-coast-brown-ribbon-scientist-alarm/
When you hear that something strange has appeared in satellite footage, it just sounds immediately ominous. When scientists raised the alarm about a brown belt that's longer than a continent, it definitely seemed alarming. But what exactly is the brown stripe that stretches across the Atlantic Ocean? And more importantly, should we be worried?
Satellites started detecting a brown stripe that stretches from the West African coast to the Gulf of Mexico. The strange object is actually 37.5 million tons of brown seaweed, a species called pelagic sargassum, once only found in the Sargasso Sea.
For the last 15 years, however, it's been spreading into the Atlantic — which is already at its "tipping point." Researchers at the Harbor Branch Oceanographic Institute at Florida Atlantic University have been analyzing four decades of satellite data, which has documented the seaweed's rapid growth in the Atlantic. The phenomenon is now called the Great Sargassum Belt, and it's not only disrupting ocean habitats and destroying beaches — it could be accelerating global warming.
Why is the pelagic sargassum spreading at such an alarming rate? Scientists have been researching this phenomenon since the 1980s and have found that the nitrogen content in the brown seaweed has increased by 55% between 1980 and 2020 — the nitrogen to phosphorus ratio also increased by 50%.
This means that the brown seaweed isn't only getting nutrients from natural ocean upwelling — a process where warm water is pushed off the coastline to allow more cold, nutrient-rich water from the deep ocean to rise to the surface. Due to human activity — like agricultural runoff and wastewater discharge — brown seaweed is getting its nutrients from land.
Pelagic sargassum is transported by ocean currents, especially when the Amazon River floods, into the Atlantic. Instead of dying off away from its safe haven of the Sargasso Sea, the brown seaweed is thriving in this new location thanks to the added nutrients.
Over the past few decades, the rapid increase in thriving brown seaweed in the Atlantic has caused some shocking incidents. "These nutrient-rich waters fueled high biomass events along the Gulf Coast, resulting in mass strandings, costly beach cleanups and even the emergency shutdown of a Florida nuclear power plant in 1991," noted Brian Lapointe, Ph.D., the Lead Author and a Research Professor of Florida Atlantic University's Harmful Algae study.
While the brown seaweed is not harmful as a species — and even acts as a habitat for over 100 species of fish, invertebrates, and turtles — this new brown belt has massively disrupted the ecosystem. Large amounts of sargassum wash ashore and begin to rot, releasing toxic hydrogen sulfide gas as it decomposes. The rotting seaweed damages coral reefs, reduces oxygen around the beach, and emits harmful greenhouse gases that could disrupt climate feedback loops.
Researchers are monitoring the brown belt and warning that humans should reduce nutrient runoff from the shore. If nothing changes, the brown seaweed may create similar phenomena in other regions, meaning more Great Sargassum Belts across the ocean. According to recent satellite footage, there's still time to combat climate change if changes are made.
(Score: 2) by ls671 on Tuesday March 03, @11:52AM (1 child)
My first guess before I read TFS was that the Potomac river spill made it to the ocean and then the Atlantic Meridional Overturning Circulation (AMOC) took it to Africa.
https://www.npr.org/2026/02/07/nx-s1-5705313/broken-pipe-sewage-spill-potomac-river [npr.org]
Everything I write is lies, including this sentence.
(Score: 1) by khallow on Tuesday March 03, @01:25PM
I hope that was a joke. The AMOC goes the wrong way (north first) and takes an estimated 1000 years [wikipedia.org] to complete a cycle. In addition, the leak in question is about one part in ten billion by volume. It will be diluted fast once it hits ocean.
(Score: 2) by looorg on Tuesday March 03, @12:37PM (3 children)
So just like every other piece of vegetation that floats ashore then. A better question is perhaps can it be harvested? And eaten? By humans? It's normally not bad, some do contain a bit to much salt. But it can usually be harvested and dried and then eating more or less like salad.
(Score: 4, Interesting) by quietus on Tuesday March 03, @12:56PM
Given that it tends to fix nitrogen, eating it will not necessarily be the best option [nih.gov]; harvesting for use as fertilizer [wikipedia.org] is a better idea.
(Score: 5, Informative) by JoeMerchant on Tuesday March 03, @02:37PM
On the one hand, this is just nature doing its thing, exploiting food sources and reproducing to consume new excesses.
On the other hand, this is us dumping continent scale sources of new food into the ocean and creating artificial blooms of growth that the ecosystem has had nowhere near enough time to evolve into graceful integration with the food web. You get bloom and rot and death. The Florida coasts have had red tide and algae blooms forever, but their frequency and intensity have jumped way up with our screwing around with damming the waterflow out of Lake Okeechobee and our spreading of phosphate (and other) fertilizers in fields with runoff to the Gulf (the Atlantic is mostly protected by the Gulf stream sucking away our pollution, but that has its limits too...)
So, when one of these "natural blooms" happens, the algae and other microbes go wild, overpopulate, physically choke off access for other species, then they die en-masse and their decomposition microbes suck up all the oxygen and release toxins, so higher life forms like fish, occasionally up through marine mammals, also die off en-masse due to the extreme disruption of the the ecosystem. It's bigger than a forest fire and harder to escape.
And, it stinks, which is your first clue that we're doing something wrong.
🌻🌻🌻🌻 [google.com]
(Score: 3, Interesting) by ikanreed on Tuesday March 03, @03:12PM
Sometimes quantity has a quality all if it's own.
There's a lot of increasing environmental problems with exactly that character.
The atmosphere has always had co2, but doubling it in a century is basically unprecedented in geological history. Mercury is a natural element, but it's typical entry rate into ocean ecosystems is a tiny fraction of what humans have dumped in in the last 50 years, and now children can't eat tuna
(Score: 0) by Anonymous Coward on Tuesday March 03, @04:58PM (1 child)
I saw this for years in the new color weather satellite pics. I always thought it was dust being blown across from the Sahara.
I guess this is our chance to refine the stuff into oil or something
(Score: 0) by Anonymous Coward on Tuesday March 03, @05:01PM
Damn it! That's brown cloud!