A giant blob of seaweed twice the width of the continental United States is headed for the shores of Florida and other coastlines throughout the Gulf of Mexico, threatening to dump smelly and possibly harmful piles across beaches and dampening tourism season.

Sargassum — the specific variety of seaweed — has long formed large blooms in the Atlantic Ocean, and scientists have been tracking massive accumulations since 2011. But this year’s bloom could be the largest ever, collectively spanning more than 5,000 miles (8,047 kilometers) from the shores of Africa to the Gulf of Mexico.

https://www.cnn.com/travel/article/sargassum-seaweed-blob-explained-florida-scn/index.html