Sea Stars Wasting Away in Oregon, Threatens Entire Population

Just in the last two weeks, purple ochre sea stars along the Oregon Coast have been hit especially hard by sea star wasting syndrome - an illness causing these marine creatures to literally disintegrate - threatening the entire population and local ecosystem.

Oregon was largely spared last year when the epidemic was sweeping through the West Coast, spreading in California, Washington, British Columbia and Alaska.

The ochre sea star, the species most heavily affected by the debilitating disease in the intertidal zone, may possibly experience localized extinction in Oregon according to researchers at Oregon State University (OSU) who have been monitoring the outbreak.

Less than one percent of the ochre sea stars in Oregon were affected in April, and only slightly more than that by mid-May. Now, 30 to 50 percent of ochre sea stars are suffering from the syndrome. This is the largest incident of sea star die-offs researchers have ever seen.

"This is an unprecedented event," Bruce Menge, the Wayne and Gladys Valley Professor of Marine Biology in the Department of Integrative Biology of the OSU College of Science, said in a statement. "We've never seen anything of this magnitude before."

"We have no clue what's causing this epidemic, how severe the damage might be or how long that damage might last," he said. "It's very serious. Some of the sea stars most heavily affected are keystone predators that influence the whole diversity of life in the intertidal zone."

Sea stars are considered a "keystone" predator because they control local population growth of other marine animals, such as mussels and sea urchins, and their absence could threaten the local ecosystem.

So far, the disease has affected 10 species of sea stars along the West Coast, and biologists still don't understand what's causing it. Sea star wasting syndrome is a terrible illness too. Over the course of a week or less, the sea stars begin to lose legs, disintegrate, ultimately die and rot, sometimes tearing themselves apart.

OSU researchers are continuing to study the local outbreak, hopefully finding an explanation soon.