Beginning in the spring of 2013, researchers, residents, and visitors began to see sea stars (starfish) that had been killed by sea star wasting syndrome (SSWS) – also known as sea star wasting disease (SSWD). This sickness has affected over 20 different species of sea stars, causing lesions (sores) and the sea star to essentially fall apart and ‘melt’ in a few days. First recorded along the coast of Washington state, this disease has since spread up through Alaska and down to the southern tip of California and into Mexico.
Researchers at Cornell, in collaboration with many others, collected and genetically tested starfish samples to try to determine what was causing SSWS; Ian Hewson et al (2014) identified a virus (which they named sea star associated densovirus – SSaD) which could be the culprit.
The current epidemic is not the first outbreak of SSWS, two others occurred in the 70’s and the 90’s; but, this outbreak is by far the worst and the most widespread. Since beginning in 2013, the disease has swept through and decimated sea star populations. There is hope that the outbreak is winding down, since the numbers of observed sick starfish has declined according to Pacific Rocky Intertidal Monitoring at the University of California Santa Cruz. However, researchers are worried about the impacts this die-off will cause in the sea stars’ habitat because they are viewed as a keystone species.
Another spark of hope is babies! Juvenile starfish no bigger than your thumbnail have been seen in areas of Washington, California, and Oregon where the disease first hit (click here for a map of current baby starfish sightings). These little stars may be immune to SSaD, and their presence could mean sea star populations are recovering.
For more information visit:
National Geographic: Why are millions of starfish ‘melting’?
Proceedings of the National Academy of Sciences – Inner Workings: Sea star wasting