Scientists Identify Bacterial Culprit Behind Massive Sea Star Die-Off

Since 2013, a mysterious wasting disease has led to the mass mortality of over 5 billion sea stars along the Pacific Coast of North America, from Mexico to Alaska. The epidemic has affected more than 20 species, with the sunflower sea star experiencing a population decline of approximately 90% within the first five years.

Researchers have now identified the bacterium Vibrio pectenicida as the cause of this devastating disease. The study, published in Nature Ecology & Evolution, details how the bacterium was found in the coelomic fluid of infected sea stars. When healthy sea stars were exposed to this bacterium, over 90% succumbed to the disease within a week.

The discovery offers hope for intervention strategies. Scientists are considering testing the health of remaining sea stars, breeding them in captivity, and potentially reintroducing them to areas where populations have been decimated. Additionally, research into natural immunity and probiotic treatments is underway.

The decline of sea stars has had significant ecological impacts. Sunflower sea stars are key predators of sea urchins; their loss has led to a surge in urchin populations, resulting in the destruction of kelp forests. These kelp forests are vital habitats for numerous marine species and play a crucial role in coastal ecosystems.

Understanding the cause of the disease is a critical step toward restoring sea star populations and the broader marine environment. Researchers are optimistic that this knowledge will guide future conservation efforts.