5,000 miles seaweed seen from space threatens the beaches of Florida and Mexico

An enormous carpet of seaweed stretching 5,000 miles is set to cause problems along the beaches of Florida and Mexico as scientists become increasingly concerned about the impacts of the algae.

The "Great Atlantic Sargassum Belt" is a massive bloom of brown algae that stretches from the coast of West Africa to the Gulf of Mexico. It is the largest seaweed bloom in the world, weighing approximately 20 million tons, and is visible from outer space.

Seaweed is usually fairly innocuous and has benefits like providing habitats for fish and absorbing carbon dioxide. But the sargassum spanning about twice the width of the US could wreak havoc on beaches as ocean currents push it toward land.

This year's boom

While the consequences of the Sargassum Belt have concerned scientists for the past decade, experts say this year's bloom is particularly alarming, according to an NBC News report published Saturday.

Furthermore, as beached sargassum dies and rots, it has a "distinct rotten-egg smell," Insider previously reported, which has caused a huge problem for tourism in both Mexico and Florida.

Brian LaPointe, a Research Professor at Florida Atlantic University's Harbor Branch Oceanographic Institute, informed NBC that, "It's incredible. What we're seeing in the satellite imagery does not bode well for a clean beach year."

Seaweed is growing each year

The mass of seaweed is thought to be growing each year — with 2018 and 2022 having record-breaking increases, Brian Barnes, an assistant research professor at the University of South Florida's College of Marine Science, told NBC News.

Despite the piles typically washing ashore in May, he explained that beaches in Key West are already covered in algae. Beaches in Mexico, including those in Cancun, Playa del Carmen, and Tulum, are gearing up for a significant sargassum buildup this week. 

Negative effects

The negative effects of the mass of algae are manifold — it can destroy coastal ecosystems, suffocate coral, harm wildlife, threaten infrastructure, and decrease air and water quality, according to Sky News.

One study in 2019 suggested that deforestation and fertilizer use might be responsible for the mass' alarming rate of growth—the effects of which are all exacerbated by climate change.