An unprecedented influx of sargassum is smothering Quintana Roo’s shores—35 of 100 monitored beaches report high levels—emptying beachfront restaurants and straining cleanup crews as authorities scramble to protect the tourism-dependent economy.

An unprecedented influx of sargassum is smothering Quintana Roo’s shores—35 of 100 monitored beaches report high levels—emptying beachfront restaurants and straining cleanup crews as authorities scramble to protect the tourism-dependent economy.