Wednesday, March 08, 2023

The creeping threat of the Great Atlantic Sargassum Belt

 


Seaweed has been having a moment. Eco-influencers and columnists rave about its benefits, in everything from beauty products to biofuels. Jamie Oliver has embraced it as a recipe ingredient; Victoria Beckham uses it to keep off the pounds. And they’re right: seaweed is packed with nutrition, it sucks up carbon and is an amazingly versatile addition to the green economy.

But one type of seaweed is not a benign force. Vast fields of sargassum, a brown seaweed, have bloomed in the Atlantic Ocean. Fed by human activity such as intensive soya farming in the Congo, the Amazon and the Mississippi, which dumps nitrogen and phosphorus into the ocean, the sargassum explosion is by far the biggest seaweed bloom on the planet. The Great Atlantic Sargassum Belt, as it’s known, is visible from space, stretching like a sea monster across the ocean, with its nose in the Gulf of Mexico and its tail in the mouth of the Congo.

Sargassum’s appearance can be deceiving. It is beautiful, layered like golden mats on the surface of the open ocean. Distinguished by bubble-like formations in its stems that keep it floating on the surface, pelagic sargassum has sloshed about in the Atlantic since well before Christopher Columbus sailed across the wide Sargasso Sea: in 1492, he wrote that he feared his boat would be trapped in it. But even early witnesses recognised its value: it provides a safe harbour and breeding ground for fish, turtles and other marine life. Under the surface it teems with life, like an upside-down reef.

 What is alarming, is the rate at which it is growing....more

No comments: