Severyn Korneyev/California Department of Food and Agriculture
Millions of tons of sargassum wash up on beaches across North America every year. Exposure can lead to breathing problems, and it costs millions to clean it up.
Amy Siewe
Picture by Tambako the Jaguar/Getty Images
Rodger Mallison/Fort Worth Star-Telegram/Tribune News Service/Getty Images
Anadolu Agency / Contributor / Getty Images