Seastar wasting syndrome

2013 is turning out to be a bad year for seastars (starfish) along the west coast of North America. As documented by this UC Santa Cruz monitoring webpage, a wasting disease of unknown origin (possibly caused by bacteria or a virus) is causing seastars of several species to fall apart. The map provided by the monitoring group shows all of the places where affected seastars have been found. Seastars on the seashore and below the surface are being found with the disease.

I happened upon a Pisaster ochraceus in the mid-intertidal zone at Hopkins Marine Station today that was exhibiting symptoms of the wasting syndrome. As shown below, one of the arms was “melting” off and was covered in white, gooshy lesions. Those lesions were also present on two of the other arms.

A Pisaster ochraceus seastar exhibiting symptoms of the wasting syndrome. Lesions and "melting" tissue are circled in red.

A Pisaster ochraceus seastar exhibiting symptoms of the wasting syndrome. Lesions and “melting” tissue are circled in red.

Another view of the unhappy seastar.

Another view of the unhappy seastar.