Scientists still don't know what causes a mysterious disease responsible for widespread sea star die-offs, but they do know it has spread to a new area: the Oregon Coast.
Sea stars infected with the disease physically deteriorate before they die. In some cases, afflicted arms break off from the sea star's body and walk away before dissolving completely. Scientists suspect a bacteria or virus is causing it, but they don't know for sure. Until April, there had only been a few cases reported in Oregon.
More: PBS NewsHour.