Tourists sit on a beach near Sargassum algae in Cancun, August 11, 2015. The Sargassum algae contains biting sand fleas and releases a pungent smell as it decomposes. It has choked beaches in resorts throughout the Caribbean including Cancun this season, prompting local authorities to launch a large-scale clean-up operation. (Photo by Edgard Garrido/Reuters)
