Sea star (noun): A multilimbed carnivorous invertebrate that can regenerate its own arms if its central nervous system is intact. Though commonly called a starfish, it is not a fish.

Sea stars are known as a keystone species, an integral link in the food chain, because they’re both predator and prey. If they disappear, the whole ecosystem will be impacted.


The Disease
 

Step 1: White lesions form on the stars, usually at the joints where the arms meet the body.

Step 2: The lesions grow, and some stars lose their appendages. “The arms start ripping away from the body,” Miner says. 

Step 3: The stars deteriorate into a pile of goo. Once lesions appear, all the stars in an area can die within weeks. Miner says juvenile stars fare better than older ones, but often whole populations are wiped out.


The Cause

No one knows what causes sea star wasting. The strongest theories from researchers: 

Temperature Warming waters could be a factor since past die-offs have occurred in El Niño years, when the Pacific temperature is elevated. 

Environmental insult Something in the water, like a chemical, could be triggering the deaths. Initially the Fukushima nuclear spill was blamed, but it has since been ruled out. 

Pathogen: A disease could be responsible, and scientists are currently looking at how one might spread along the coast in such a sporadic manner.

All of the above There are also theories about interrelated causes, like that increased temperatures could have activated a pathogen.

 

By the Numbers
 

30: Number of sea star species in Washington

20: Number of species affected
 


35 years: Maximum lifespan of a sea star

2 weeks: Average lifespan of a star with wasting syndrome'

 

Timeline
 
June 2013: Steve Fradkin, an Olympic National Park ecologist, first spots dying stars at, where else, Starfish Point. Fall 2013 Die-offs are reported as far south as Orange County, California, and as far north as Anchorage, Alaska. The disease appears at points along the coast without any apparent pattern. October 2013 The syndrome is observed in Puget Sound along Hood Canal and in Bellingham Bay. Populations in those areas are decimated.


April 2014 Oregon reports its first sick stars.


Summer 2014 Stars in the San Juan Islands show signs of wasting.


July 2014: The Seattle Aquarium loses all its captive Sunflower sea stars (Pycnopodia helianthoides).
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