A "spooky disease" causing starfish to lose their limbs and die in a matter of days in record numbers is raging along the US west coast. Scientists are struggling to determine the reach and source of the deadly syndrome known as ‘star wasting disease’.
Since June, wasting sea stars have been spotted in dozens of
coastal sites ranging from southeast Alaska to California. In one
surveyed tide pool in Santa Cruz, 90 to 95 percent of starfish
were killed by the disease.
Sea star wasting syndrome usually starts with white lesions on the arms of the starfish that spread inward, causing the animal to dissolve in less than a week. The disease was previously linked to a rise in seawater temperatures, which is not the case this time.
"It's pretty spooky because we don't have any obvious culprit for the root cause even though we know it's likely caused by a pathogen," chair of the Department of Ecology and Evolutionary Biology at the University of California at Santa Cruz's Long Marine Lab, Pete Raimondi, told Reuters.
Although starfish have suffered from the deadly syndrome on and off for decades, the disease never hit such record-breaking numbers of sea creatures. According to Raimondi, the mortality rates have been higher than ever before.
"Their tissue just melts away," a biologist and researcher with the Multi-Agency Rocky Intertidal Network that monitor tidal wildlife and environment along the West Coast, Melissa Miner, told Reuters.
The syndrome primarily affects the mussel-eating Pisaster ochraceus, a large purple and orange starfish which is considered an important indicator for the health of the intertidal zone. Marine biologists from the Long Marine Lab say, however, that at least 10 species of sea stars have also shown signs of the disease since the outbreak of the disease in June.
Meanwhile, if the numbers of Pisaster ochraceus, which feeds on mussels, begin to decrease, mussels could crowd the ocean, disrupting biodiversity.
It’s hard to estimate how many starfish on the West Coast have already been killed by the fatal disease or could be in the future.
"We're way at the onset now, so we just don't know how bad it's going to get," Raimondi said.