Bacteria Blamed for Devastating 90% Decline in Sunflower Sea Star Populations

In the past decade, a mysterious sea star wasting disease has sparked a mass die-off of more than 20 species of sea stars, or starfish, along the Pacific coast of North America. The epidemic, which began in 2013, has been particularly devastating for the sunflower sea star, a species that lost around 90% of its population in the outbreak's first 5 years.

Researchers have now identified the cause of this deadly disease - a bacteria called Vibrio pectenicida. The findings, published in the journal Nature Ecology and Evolution, solve a long-standing mystery about the epidemic that has ravaged sea star populations from Mexico to Alaska.

The disease causes sea stars to develop lesions and eventually lose their arms, leading to a gruesome demise. Scientists say the loss of these voracious predators has had a cascading effect on coastal ecosystems, allowing sea urchin populations to explode and decimate kelp forests that provide critical habitat for a wide range of marine life.

With the cause of the disease now known, researchers are hopeful they can develop interventions to help restore sea star populations and, in turn, revive the damaged kelp forests that are often referred to as the "rainforests of the ocean."