Researchers say they have identified the mysterious killer of more than 5 billion sea stars

Researchers say they have identified the mysterious killer of more than 5 billion sea stars Science Aug 7, 2025 7:30 PM EDT

WASHINGTON (AP) — Scientists say they have at last solved the mystery of what killed more than 5 billion sea stars off the Pacific coast of North America in a decade-long epidemic .

Sea stars – often known as starfish – typically have five arms and some species sport up to 24 arms. They range in color from solid orange to tapestries of orange, purple, brown and green.

Starting in 2013, a mysterious sea star wasting disease sparked a mass die-off from Mexico to Alaska. The epidemic has devastated more than 20 species and continues today. Worst hit was a species called the sunflower sea star, which lost around 90% of its population in the outbreak’s first five y