Scientists discover bacteria behind mass sea star deaths

In recent years, scientists have made significant progress in understanding a devastating epidemic that has decimated sea star populations off the Pacific coast of North America. Marine ecologists discovered that the wasting disease responsible for killing over 5 billion sea stars, including various species, was linked to a specific bacterium known as Vibrio pectenicida. This discovery came after a decade of research that began when this epidemic first emerged, leading to a notable decline in several species including the sunflower sea star, which suffered a 90% population loss in its initial years. The research revealed that earlier investigations misidentified the cause of the epidemic, initially suspecting a virus. Further analysis, however, focused on the coelomic fluid of the sea stars, providing insight into the bacterial presence that exacerbated the disease and caused the sea stars to grow lesions and lose limbs. The findings were published in the journal Nature Ecology and Evolution, shedding light on the ongoing crisis affecting marine ecosystems. With the extinction of large numbers of sea stars, the imbalance in the ecosystem has led to a surge in sea urchin populations, which in turn devastated kelp forests vital to marine life. Researchers believe that restoring sea star populations not only is critical for the species itself, but also for the health of the entire ecosystem. Current efforts include testing remaining sea stars for natural immunity and exploring the effectiveness of potential treatments. The hope is to revitalize both sea star populations and the kelp forests, akin to rainforests of the ocean, critical for housing numerous marine animals like fish, seals, and sea otters. The impact of the findings is substantial, offering pathways for conservation and restoration of these crucial marine habitats.