EXPLAINER: Behind big seaweed belt lurking for some beaches

There's a pesky problem in a wide stretch of the Atlantic Ocean that's likely to wash up on some beaches later this year: Seaweed. Lots of it. The Great Atlantic Sargassum Belt is a biomass of thick, brown seaweed in patches scattered across a 5,000-mile belt of the Sargasso Sea well off the southeastern U.S. coastline. The sargassum is expected to wash ashore in coming months on some Florida beaches, in the Caribbean islands and Mexico's Yucatán Peninsula. Sargassum blooms aren't new, but this year's appearance in February was an early start for such a large algae mass. On shore, sargassum is a nuisance — carpeting beaches and releasing a pungent smell as it decays. For hotels and resorts, clearing the stuff off beaches can amount to a round-the-clock operation.