During the summers of 2013 and 2014, populations of sea stars along the west coast from Alaska to Mexico were decimated by the sea star wasting disease (SSWD) epizootic. Two of the most highly affected species along this range were Pisaster ochraceus (the Ochre Sea Star), the most common intertidal species, and Pycnopodia helianthoides (the Sunflower Sea Star), the most common subtidal species, both of which are endemic to the US western coast. REEF Volunteer Fish Survey Project were used to evaluate populations of the Sunflower Star as part of this study (REEF surveyors do not monitor Ochre Stars because they are intertidal). The REEF data showed an extraordinary decimation of Sunflower Sea Stars, with no sign of recovery three years after the SSWD epizootic. In contrast, data collected by the authors on Ochre Stars in the San Juan Islands revealed high fatality rates (over 90%) associated with SSWD during the summer of 2014, followed by low levels of disease in the summers of 2015, 2016, and 2017. Population levels of Ochre Stars following the epizootic remained stable but small, and shifted in size structure from larger to smaller stars. Extremely low population size of Sunflower Stars raises concern about the capacity of this species to recover, as well as to resist other stochastic events in the future. These findings were presented at the Salish Sea Ecosystem Conference in Seattle, WA, in 2018.

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