Sea Star Wasting Syndrome

ARTICLE intro SSWS by RL 512x219

All along the North American Pacific coast, sea stars are succumbing to a poorly-understood malady known as sea star wasting syndrome (SSWS). First twisting into odd, tortured positions, otherwise healthy-looking individuals soon develop lesions on their body and arms, which whiten with rot as their tissues degrade. Afflicted stars may appear to deflate or “waste away” as the malady progresses, their arms and skin may slough off, and most die in a matter of days.

Since June 2013, when the first confirmed case of this SSWS episode was reported in Ochre Stars on Washington’s Olympic Peninsula, thousands more sightings have poured in, affecting numerous echinoderm species from Alaska to the Baja Peninsula. Some of these echinoderms, such as Ochre Stars and Sunflower Stars, are considered keystone species—they exert an outsized influence on their respective habitats, serving to guide ecological processes through their behavior. The rapid decline of such species could trigger a cascade of unforeseen consequences.

This sea star die-off is not without precedent, though. Similar events have been recorded in past decades on the Pacific coast, presumably from SSWS or something very much like it, but the magnitude and geographic scope of this episode are without parallel. Researchers are scrambling to first determine what causes the wastinga viral component is strongly implicated—and then find a way to stop its spread.

To learn more about SSWS and how citizen science is helping to track its devastating extent, visit the Pacific Rocky Intertidal Monitoring site. Or go to Partnership for Interdisciplinary Studies of Coastal Oceans’ SSWS page.