Wide Sargasso seaweed: 5,500-mile algae belt keeps on growing

'Great Atlantic Sargassum Belt' now appears almost every year, forming largest record bloom

It weighs 20m tonnes, stretches from west Africa to the Gulf of Mexico, and washes up on beaches creating a malodorous stench. Now scientists say a vast swathe of brown seaweed could be becoming an annual occurrence.

Researchers say the explosion in sargassum seaweed first materialised in 2011. But new research shows it has appeared almost every year since then, forming the largest bloom of macroalgae ever recorded. What's more, the seaweed band - dubbed the Great Atlantic Sargassum Belt - seems to be getting bigger.