A team of researchers from Washington and British Columbia has solved a deadly mystery affecting sea stars along North America’s West Coast for over a decade. The pathogen behind the disease, known as Vibrio pectenicida, was identified as a strain of bacteria that sicken corals and shellfish.
A mass die-off of ocean-shaking proportions began in 2013 among sea stars from Alaska to California, with over 5 billion sunflower stars, or 90% of their global population, affected. The disease is caused by the proliferation of key predators, sea urchins, which lead to widespread losses of productive kelp forests.
The researchers avoided microbial contamination and used foot baths and ultraviolet-treated seawater to study the disease. They found large amounts of Vibrio pectenicida in sick sunflower stars and were able to isolate the bacteria and grow it in the lab.
The discovery is a significant breakthrough, as it confirms that Vibrio was the cause of the wasting disease. The research team has already started testing 15 other species and developing probiotics to help healthy stars ward off the disease.
This finding is timely, given the sunflower star’s critically endangered status. The U.S. government proposed listing the species as threatened in 2023, and researchers are hopeful that with this new information, they can start monitoring programs to restore sunflower star populations and kelp forests.
However, the future of labs like Marrowstone Marine Field Station is uncertain due to budget cuts and proposals to eliminate biological research arm. The discovery highlights the importance of continued funding for scientific research and conservation efforts.
Source: https://www.opb.org/article/2025/08/05/northwest-scientists-crack-case-melting-sea-stars-after-decade