Discovery of the Decade” – so proclaimed Drew Harvell, the disease ecologist at the University of Washington who co-led the research unveiling this critical breakthrough.
After years of uncertainty, scientists have finally solved the mystery behind sea star wasting disease (SSWD) – a devastating epidemic that began in 2013 and has wiped out billions of sea stars along the Pacific Coast. The most affected species? The sunflower sea star (Pycnopodia helianthoides), whose population dropped by over 90% and is now listed as critically endangered.
🧪 The Culprit Revealed: Vibrio pectenicida Strain FHCF‑3
This previously under‑the‑radar bacterium has been identified as the pathogen behind the disease. Researchers analyzed coelomic fluid – essentially sea star blood -and found massive loads of V. pectenicida in sick individuals, while healthy stars showed only low or no presence. In lab experiments, sea stars exposed to the cultured strain developed wasting disease and died within about 12 days.
🧬 Why It Matters
Ecological ripple effects: Sunflower sea stars help keep sea urchins in check. With their collapse, sea urchin populations exploded – leading to a loss of over 95% of kelp forest canopy in northern California, which in turn degraded coastal ecosystems worldwide.
Powerful path forward: This discovery enables detection of disease in both wild and captive sea stars, investigation of natural resistance, and even experimental therapies like probiotics or bacteriophages.
🔭 What’s Next
Test archived samples from regions like California to confirm V. pectenicida presence in those die-offs.
Investigate whether warmer ocean water contributes to outbreaks, since Vibrio bacteria thrive in warm temperatures.
Explore breeding and transplant programs using potentially resistant individuals – hosted in quarantine facilities like UW Friday Harbor and USGS Marrowstone – toward ecosystem restoration.