UW News

November 24, 2014

Sea-star wasting culprit is virus

Disintegrating sea stars – a process described as melting, with the arms detaching and crawling away from each other – is being caused by a virus that’s been detected in West Coast waters for more than 70 years.

That’s according to new findings published this week in the Proceedings of the National Academy of Sciences by 24 co-authors including the University of Washington’s Carolyn Friedman, a professor of aquatic and fishery sciences, and Colleen Burge, who earned her bachelor’s and doctorate from UW and is now back as a postdoctoral researcher here after four years of postdoc work at Cornell University.

woman leans over water tank working on sea star

Colleen Burge at work in lab.Morgan Eisenlord

Following earlier observations that suggested the disease was contagious, Burge led experiments that confirmed it was transmitted from infected sea stars to healthy individuals. It was an important piece of the puzzle pointing to a virus.

The work is the first to pinpoint a densovirus as the likely culprit behind the current episode of sea star wasting that has killed millions of the animals along the West Coast and up into Alaskan waters. Scientists don’t, however, understand why the virus – which isn’t new – is causing such widespread devastation.

The PNAS paper, for example, reported that the virus was found in museum specimens of sea stars collected in 1942, suggesting that, like many marine pathogens, it was already present in the environment before the outbreak. Indeed, it’s also been detected in plankton, sediments and sea star brethren such as basket stars.

It remains to be seen what triggers outbreaks and how the mass sea star mortalities will alter the near-shore communities throughout the North American Pacific Coast, the co-authors say.