By Jeanna Bryner
A mysterious disease that is turning sea stars to goo has taken off along the Oregon coast, with up to half or more of the creatures being infected in just the last few weeks, scientists say.
Until now, Oregon was the one state along the U.S. West Coast essentially spared from the disease. In April, researchers estimated less than 1 percent or so of the purple ochre sea stars (Pisaster ochraceus) living within 10 sites along Oregon’s intertidal zones — which provide an easily accessible place to monitor sea stars— were affected by the wasting disease. By mid-May that percentage had gone up slightly, and then after that it seemed to skyrocket.
“The percentages we saw last week, they were as high as 40 to 60 percent of the population that’s showing signs of wasting,” said Bruce Menge, a marine biologist at Oregon State University, who is studying the wasting disease in Oregon.
Turning sea stars to goo
Sea star wasting syndrome causes a sea star’s body to disintegrate, ultimately leading to death.
The disease tends to progress from no outward signs to behavior changes in which the sea stars cross their arms and seem to collapse on themselves. Then white lesions appear on the surface of the sea star’s body that turn into holes; those lesions are typically followed by the disintegration of skin around the lesion and the loss of a limb or several limbs, and in extreme cases the animal’s entire body is affected by the syndrome. Some of the creatures physically tear their bodies apart in the process, scientists say.
“We’ve seen a number of cases where all that’s left is a puddle of their skeletal parts and a bunch of bacteria eating away at the tissue,” Menge told Live Science. “It’s a pretty gruesome thing to see.”
The current outbreak of sea star wasting syndrome was first reported in June 2013 along the coast of Washington by researchers from Olympic National Park. Since that report, die-offs have been documented everywhere from California to Alaska and even along the East Coast from Maine through New Jersey.
“Wasting has been known for a long time, but usually it’s very localized to a single site or single region,” Menge said. When that’s the case, as it was last August just north of Vancouver, British Columbia, the chances for recovery are high since the plankton, or floating forms, of the sea stars from healthy, nearby populations can recolonize those areas that were hit.
“The thing that is worrisome now is that it’s happening pretty much all along the West Coast, even up into Alaska,” Menge said.