Another person has asked me to share his photo and observation from DuPont Beach just south of Juneau on April 28, 2019. He observed approximately 700 dead sea stars that could be Mottled Stars on the beach. Appendages were intact suggesting the die-off might be related to stormy weather that happened around the 22nd.
I haven't seen enough decent photos of this local event to diagnose SSWD (Sea Star Wasting Disease). This time of year (March-April) there can be mass strandings/die offs associated with spawning events but this has also been the time we have seen SSWD outbreaks in SEAK in last ~5 years. This particular location has some of the highest densities of sea stars I have ever seen and may have reached capacity or prime conditions for SSWD to have an outbreak (high densities and warm temps).
Comments from LEO Editors:
According to the Morro Bay Estuary Program, Sea Star Wasting Syndrome is a series of symptoms that lead to mortality. Typically, sea stars will develop lesions that eventually become surrounded with decay, causing a fragmentation of the sea star's body and eventual death. Erica Lujan