A mysterious disease that causes sea stars to disintegrate is exploding on the Oregon Coast.
Oregon State University marine ecologist Kristen Milligan said Wednesday that Oregon was largely spared last year as the disease known as sea star wasting syndrome spread in California, Washington, British Columbia and Alaska.
But monitoring of tide pools along much of the coast shows the number of sea stars affected has jumped from just 1 percent in April to as high as 50 percent. The greatest concentration is at Fogarty Creek north of Depoe Bay. One was found as far north as Seaside.
"This is an unprecedented event," Bruce Menge, a professor of marine biology at OSU, said in a statement. "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."
Milligan, research program coordinator for the Partnership for Interdisciplinary Studies of Coastal Oceans at OSU, says the cause of the disease is still unknown. Scientists are studying the disease.
In Oregon, the disease is primarily affecting ochre sea stars, the purple and orange creatures commonly seen in tide pools, but in all, it has affected 10 different species up and down the coast. Among them is the sunflower sea star, which has 16 to 20 appendages, grows as big as 3 feet in diameter, and lives close to shore in areas not exposed by low tides.
Losing so many sea stars — a major predator of mussels and sea urchins — could throw the marine ecosystem out of balance, Milligan said.
More mussels would crowd out other species, such as algae. More sea urchins would eat more kelp, reducing habitat for fish, she said.