By Reeves Wiedeman
The walls of seaweed first started washing over the white-sand beaches of Tulum, Mexico, in 2015. They came from deep in the Atlantic and across the Caribbean, darkening the neon-blue water. Some of the seaweed was puke brown, while the rest was dark red, and in the summer it was so thick that swimming was impossible. Dead fish and other sea creatures were mixed in, and the piles on the beach smelled like rotten eggs. Where was it coming from? Development in the Amazon was leaching more fertilizer into increasingly warmer oceans — maybe that was it. But some residents of Tulum, which has long attracted visitors predisposed toward the mystical, thought that Mother Nature had simply had enough: The first time one local remembered seeing the seaweed was after one of Tulum’s many oceanfront venues hosted a wild party and put up a barrier to close off the beach.
“Look at that black wave,” Eugenio Barbachano, Tulum’s director general of tourism, said one afternoon in January, staring at the brackish sea. “That’s my biggest fucking enemy.” He was eating octopus tacos at Be Tulum, one of the poshest hotels on Tulum’s five-mile strip of beach. Rooms at Be Tulum were going for $2,000 a night, which, Barbachano noted, with…
