This group of Pisaster orchraceus was found on Orcas Island, WA.
This Pycnopodia helianthoides affected with SSWD immediately autotomized upon entering the lab.
This Pisaster ochraceus is at an extreme stage of SSWD.
In 2013, an epidemic (or an epizootic, if you'd like to be proper) swept up the North American west coast. Sea stars of over 20 different species were succumbing to what has been termed "Sea Star Wasting Disease" or SSWD (also termed SSW Syndrome by some research groups). Sea stars knot and twist erratically, develop lesions of exposed tissue, and in the later stages even autotomize - their arms break off and crawl away. In the Harvell Lab I worked with numerous researchers on SSWD. We have largely investigated the ecology of the disease (from temperature drivers to community impacts). I have so far been involved in two publications on the disease:
Montecino-Latorre, D., Eisenlord, M.E., Turner, M., Yoshioka, R., Harvell, C.D., Pattengill-Semmens, C.V., Nichols, J.D. and Gaydos, J.K., 2016. Devastating Transboundary Impacts of Sea Star Wasting Disease on Subtidal Asteroids. PLoS One, 11(10), p.e0163190.
Eisenlord, M.E., Groner, M.L., Yoshioka, R.M., Elliott, J., Maynard, J., Fradkin, S., Turner, M., Pyne, K., Rivlin, N., van Hooidonk, R. and Harvell, C.D., 2016. Ochre star mortality during the 2014 wasting disease epizootic: role of population size structure and temperature. Phil. Trans. R. Soc. B,371(1689), p.20150212.
Fuess, L.E., Eisenlord, M.E., Closek, C.J., Tracy, A.M., Mauntz, R., Gignoux-Wolfsohn, S., Moritsch, M.M., Yoshioka, R., Burge, C.A., Harvell, C.D. and Friedman, C.S., 2015. Up in arms: immune and nervous system response to sea star wasting disease. PloS one, 10(7), p.e0133053.
Efforts in understanding the disease and its pathogen are ongoing for the Hewson Lab, which first described the virus Sea Star associated Densovirus, or SSaDV. You can follow their work here. UCSC researchers are also driving forward of monitoring the disease and its ecology, see here. Although the disease event was massive, the research response was also huge, and unfortunately I can't list all the researchers moving these efforts forward here.
Sea Star Wasting Disease,
FRIDAY HARBOR, WA