Long-term nearshore subtidal sea star observations pre and post Sea Star Wasting Disease (SSWD) in the central US Strait of Juan de Fuca.

In June of 2013 sea stars (asteroids) on the Northeast Pacific Coast began to experience an outbreak of sea star wasting disease (SSWD), which caused mass die-offs from Alaska to Baja. Scuba surveys to assess pre and post Elwha River dam removal effects on benthic macroalgae, macroinvertebrates, and fish, in the Elwha subtidal region were conducted in July and August from 2008 to 2015. Two control sites to the east and west of the Elwha were also surveyed. Surveys include a comprehensive data set of densities for 14 species of sea stars. Symptoms of SSWD were not observed in any sea star during the 2013 surveys and densities were consistent with the 2008-2012 surveys. However, densities dropped dramatically in 2014 for most species except blood stars (Henricia spp.) Sea stars exhibiting SSWD symptoms (lesions, loss of turgor, limb autotomy) were also observed at multiple sites. Results from the 2015 surveys show continued low densities or a complete absence of some species (vermillion star, Mediaster aequalis), but evidence of recovery was also observed for the sunflower star (Pycnopodia helianthoides). While no Pycnopodia adults were encountered, numerous juveniles were seen at many locations. These surveys will continue and therefore provide the opportunity to assess effects of SSWD on sea stars and, in turn, how sea star population changes affect other components of the shallow subtidal community