The baffling, gruesome plague that is causing sea stars to tear themselves to pieces – ‘It’s the stuff of nightmares’Posted by Jim at Tuesday, June 30, 2015
By Nathaniel Rich
13 May 2015
(Vice) – Allison Gong is a marine biologist, so she knows perfectly well that a sea star has no blood, brain, or central nervous system. Still, she can't help thinking of the stars in her lab as pets. "Because of my weird personality," she told me, "I form an emotional attachment, even though obviously they can't reciprocate."
This attachment has deepened during the 20 years that she has worked in the Long Marine Laboratory at the University of California, Santa Cruz, where she exhibits the stars to undergraduates in her marine-biology classes. (One of her first lessons: The term "starfish" is a misnomer, because stars are not fish.) Until recently, Gong had 15 stars in her care: eight bat stars, five ochres, one leather, and a rainbow. She had developed a daily routine. Nearly every morning she entered her lab at 8:30 AM and saluted her menagerie with a cheerful "Hey, guys!" She checked "to make sure everybody's fine": If a star was climbing off the table, for instance, she'd prod it back into the water, with a gentle reprimand: "Guys! You know you need to get back in there." She recorded the temperature of the water, which is piped in from the shallows of Terrace Point, the reef on which the Long Marine Lab is situated; from the lab's windows it is common to see cresting dolphins, back-paddling sea lions, and breaching humpback whales in the surf below. Finally, Gong fed the stars frozen squid or lake smelt that she carefully diced into small, digestible bites. None of the stars, which typically live about 35 years in the wild and can survive more than three times as long in captivity, had ever died. At least not of natural causes. Some years ago Gong accidentally dropped a tank on a star, crushing it. "I thought it would recover, but it didn't. I felt bad about that."
Gong was therefore unprepared for the discovery she made during Labor Day weekend in 2013. No sooner had she greeted her charges ("Hey, guys!") than she realized that "somebody had died." The bat stars, aggressive scavengers, had glommed together in a single ball—an ominous sign. Gong peeled them off, one by one, until she found what they had been consuming: the corpse of an ochre sea star, their tablemate for the past five years.
Two days later she noticed that some of the other stars in the water table did not look well. "Their behavior was a little off," she said, putting it mildly. Some of their arms were twisted around their stomachs, as if the animals were trying to hug themselves. Healthy stars, especially ochres, have a rough texture and a firm consistency. But these looked "kind of mushy," like deflating party balloons. "It got to the point where I was afraid to open the door," she said. The next day a disturbed lab assistant reported that one of the stars had lost an arm. When Gong returned the day after that, the table looked "like an asteroid battlefield." The stars were squishy and pockmarked with pullulating white lesions. Sometimes their guts spilled out of the lesions. More arms had detached. The arms continued to crawl, disembodied, around the tank. […]
Today they are the only stars remaining in the lab. "It's the stuff of nightmares," Gong said. "I had never seen anything like that. I'd seen animals die, but it's just a one-off. Something dies, and you get on with your life. But there was no getting on." […]
This has been a familiar pattern along the Pacific Coast this winter. As the Wasting has persisted, stars have disappeared almost completely in many locations. In others, stars survived a brush with the epidemic and seemed to recover, as if having developed immunity—only to be wiped out months later. Raimondi estimates that between 1 and 10 million stars have died so far. In the intertidal region alone, the mortality rate averages about 75 percent. But smaller sea stars have been observed at a number of sites in which the larger ones have vanished. […]
Peter Raimondi, the chair of UCSC's Ecology and Evolutionary Biology Department —unflappable, seasoned, sober — said he is not especially concerned. "A lot people ask me, 'Are they going to go extinct? Is there going to be a catastrophe? Is the whole ecosystem going to collapse?' The answer is no. I've seen this before, and the system recovered."
Some of the younger scientists and volunteer surveyors I met were less sanguine. They have been traumatized by observing in their own lifetime extinction events and environmental calamities that are unprecedented in the history of human civilization. The idea that the sea stars might be evidence of some decisive, more profound transformation of the marine ecology does not seem to them so far-fetched. […]
"It feels apocalyptic," said Mary Ellen Hannibal. "Whatever is going on with the sea stars has the sense of an immersive event that's not visible to the eye, that's pulling species out from underneath." [more]