Cause of 5 Billion Sea Star Deaths Finally Discovered

Scientists have finally discovered the cause behind one of the most devastating marine die-offs in recent history: a strain of bacteria called Vibrio pectenicida.

For over a decade, researchers have been searching for the reason behind the mysterious and gruesome death of more than 5 billion sea stars, particularly the sunflower sea star, which has lost over 90% of its population from Mexico to Alaska.

The epidemic, known as sea star wasting disease, caused starfish to twist, develop lesions, and eventually disintegrate. While early theories pointed to viruses, a new study published in Nature Ecology and Evolution has confirmed that a novel strain of Vibrio pectenicida found in the sea stars’ coelomic fluid, their version of blood, is the true culprit.

This discovery has major ecological implications. With sea stars gone, sea urchins exploded in number, destroying up to 95% of Northern California’s kelp forests, vital underwater habitats often called the “rainforests of the ocean.” Scientists now hope this breakthrough can help restore both sea star populations and balance in fragile marine ecosystems.