Sea stars, also commonly called starfish, are among the most abundant animals along the U.S. West Coast. But now scientists say an epidemic spurred by warming ocean waters is decimating sunflower sea stars, a critical predator in kelp forests. The sea stars’ collapse could wipe out the shallow water ecosystems that provide a home for seals, sea otters and commercially important fish.

“The epidemic was catastrophic and widespread,” said Drew Harvell, a marine ecologist at Cornell Universit