Scientists on the U.S. West Coast are at a loss to explain what's killing sea stars, also known as starfish. In some places, 95 percent of the sea star population has died, causing changes to coastal ecosystems. Photo: CBS News

By Ben Tracy
12 November 2013 SANTA CRUZ, California (CBS News) – Scientists on the West Coast are at a loss to explain what’s killing sea stars, also known as starfish. In some places, 95 percent of the starfish population has died. Marine biologist Pete Raimondi showed CBS News the tide pools along California’s Monterey Bay. Thousands of bright sea stars usually line these shores. In less than two months, they’ve vanished. Raimondi said the mystery of what is happening to the sea stars is “immense.” “I mean, that’s probably, from a scientific point of view, one of the most intriguing things,” he said. “We have no obvious culprit.” His University of California Santa Cruz research team is finding sick sea stars underwater, their limbs falling off, their bodies disintegrating. “Sea stars can go from perfectly health to completely decomposed overnight,” Raimondi said. A timelapse video shows a sea star infected with white lesions. One by one, it loses each of its arms. It happens in just seven hours. This wasting disease is typically caused by bacteria. It often happens during El Niño years when ocean temperatures warm and bacteria grows more quickly. But there is no El Niño now. The disease is more widespread than ever, stretching from Alaska to Southern California. Last year, a healthy sea star population near Vancouver, Canada, covered the sea floor. Now, they are nowhere to be found. “We’ve never seen it like this, never,” Raimondi said. [more]

What’s wiping out the starfish in California?