Something is killing starfish up and down the West Coast and no one knows what.
Amysterious illness that first appeared in June in Washington state hasnow spread from Sitka, Alaska, to San Diego. Starfish first waste awayand then "turn into goo," divers say. Whatever is causing it can spreadwith astonishing speed - a healthy group of starfish can die in just 24hours.
"It's widespread, it's very virulent and it's unlikeanything we've seen in the past," said Pete Raimondi, a marine ecologistat the University of California-Santa Cruz who is one of the leadresearchers in an international effort to track the outbreak.
Theailment seems to hit starfish the hardest, with smaller numbers of seaurchins and sea cucumbers reported falling to it. No one knows whatpercentage of the West Coast's starfish are affected but in some areasthey've been wiped out.
So far at least 12 different starfish species are known to be at risk, Raimondi said.
Marinebiologists call starfish "sea stars" because they are not actuallyfish, but invertebrates. They've dubbed the ailment "sea star wastingsyndrome."
The first case was reported in a tide pool inWashington state's Olympic NationalPark in June. Within weeks sea starsin the Vancouver Aquarium in British Columbia were dying, and sea starsnear Sitka, Alaska, also began to fall ill.
The animals first"look a little bit odd," said Mike Murray, director of veterinaryservices at the Monterey Bay Aquarium in Monterey, Calif. "Their armsmay be twisted or weirdly positioned."
They then develop what looklike tiny wounds on their surface and bits of whitish discoloration.Within days and sometimes hours, the animal begins to waste away andfall apart. "It's almost like they're melting," he says. "They turn intoslime or goo, they just kind of disintegrate."
Scientists areasking recreational divers to report outbreaks. Don Noviello is a memberof the Kelp Krawlers Dive Club in Olympia Wash. He and a dive partnersaw their first infected sea stars on Dec. 21.
"It's like they become zombies of the sea," Noviello said. "I saw a leg walking away by itself," he said.
Scientists are scrambling to find the cause. The National ScienceFoundation gave rapid response research grants over the summer so marinebiologists could begin intensively studying the problem. Groups far andwide are involved, including the National Wildlife Center in Madison,Wis., Cornell University in Ithaca, N.Y., and various universities inCanada.
Teams are now going up and down the West Coast looking foroutbreaks so they can develop an accurate map of affected areas. Thelist is ever increasing. "We had our first report in Santa Barbara onDec. 7," Raimondi said. "Last week, they found five affected areasthere."
Researchers believe the sea stars' actual disintegrationand death is caused by bacterial infection, but they have no idea what'ssuddenly making them susceptible.
Raimondi put it this way:"Suppose someone's walking down the street and they get stabbed in thearm and develop an infection and die. So the infection killed them, butthe real question is this: Who stabbed them in the first place?"
Therehave been previous, small scale sea star die-offs. While they lookedsimilar, "there are only certain ways starfish can look when they die. Amelting starfish is going to look like a melting starfish," Murraysaid.
The cause could be a toxins, a virus, bacteria, manmade chemicals,ocean acidification, wastewater discharge or warming oceans. "We're notruling anything out," Raimondi said.
The fact that the ailment isso widespread is what's most troubling, said Benjamin Miner, aprofessor of marine biology at Western Washington University inBellingham, Wash. "Every time you come up with what seems like areasonable hypothesis, it's challenged because other affected placesdon't match."
Whatever is killing the sea stars is highly lethal."We've had populations go locally extinct overnight. Literally. Somespecies go from completely fine to a mush ball in 24 hours," said Miner,who's organizing the mapping project.
Starfish may seem fairlyunimportant, but they're actually a keystone species in many marineenvironments. Most live near the shore, but some inhabit the bottom ofdeep seas. Few things eat them, but they are a top predator, eatingmussels, barnacles and sea snails.
"The niche they fill is vital.If they die off, the ecological communities they live in could changefundamentally," Raimondi said.
Sea stars aren't eaten by humans,and there is no danger to people who might come into contact with them,Murray said. However, "melting sea stars, or not, any time you handlewildlife, you want to wash your hands."
Asked for a bright spot,Raimondi could only think of one: "Sea stars don't feel pain," so deathby dissolving doesn't hurt them.