A sea star is missing two limbs.(Nate Fletcher / Pacific Rocky Intertidal Monitoring Lab)
Starfish up and down the West Coast are suffering from a strange disease known as “seastar wasting syndrome,” and scientists are unsure why it is happening.
Pockets of starfish decimation have been found from Southern California to Alaska. In some places the entire seastar population has been wiped out.
(And before you get confused, seastar and starfish are two names for the same animal and I’ll be using them interchangably.)
The seastar wasting disease begins as a small sore somewhere along the seastar’s body. The sore becomes infected, most likely with bacteria, causing the animal’s tissues to decay, one limb at a time. After a few days, all that remains of the seastar is a small pile of mush.
“Imagine a wound on your finger that you never treated,” said Pete Raimondi, a professor at UC Santa Cruz who has been tracking the seastar crisis. “The bacteria would continue to build up and just eat away the flesh until it fell off. That’s how this disease goes.”
This is not the first time that the seastar population on the West Coast has fallen prey to the wasting disease. There was a major starfish die-off in Southern California between 1983 and 1984, and a smaller die-off between 1997 and 1998. Both those events took place during El Niño years, when the ocean waters were especially warm. Since we are not currently in an El Niño year, and the waters are not particularly warm, it’s hard to know what is going on, Raimondi said.
“This time we have nothing in particular to point to as to what might be causing the disease, and we don’t know when it will end,” he told the Los Angeles Times. “If this was an El Niño year, I’d already be making predictions now about when it will end.”
The seastar crisis of 2013 was first detected over the summer. Now, scientists are working to get more information about how many seastar populations are being affected. UC Santa Cruz has created a map detailing where on the coast seastar populations have contracted the disease, but most of those reports are what Raimondi calls opportunistic - someone goes to the beach, checks out the tidepools and notices a bunch of starfish missing limbs.
To get a more accurate view of how widespread the disease has become, a team of researchers has been dispatched to drive up and down the coast on a seastar observing mission that may take months.
The good news is that just because the current seastar population is taking a serious hit, it does not mean that our coastline will be devoid of starfish. “They do come back pretty quickly,” Raimondi said.
Seastars are some of the most iconic and exciting animals to see in a tide pool, and they are essential to keeping biodiveristy in the tidal community.
“Here’s the deal,” Raimondi said. “Seastars are not eaten by anything, and their predation has a dramatic effect on the rest of the community. What they do is take out the mussels, and without seastars, the mussels would dominate the space.”
Here’s hoping they figure out what’s going on soon.
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