Something’s killing off the starfish. From Maine to New Jersey researchers have been noticing a decline in starfish populations – more properly known as sea stars – and a group of scientists from Rhode Island are trying to find out why.
“It’s one of those mystery detective stories,” Marta Gomez-Chiarri, a biology professor at the University of Rhode Island, told the Providence Journal.
Just a few years ago, there had been a boom in starfish populations, to the point that they were regarded as a pest to clam diggers, oystermen, and fishermen. Now there are hardly enough left to study.
The mystery disease was first observed by URI graduate student Caitlin Delsesto. In 2011, she had been collecting sea stars to study the effects of ocean acidification but found it difficult to keep them alive in an aquarium.
“If you pick up a healthy sea star,” said DelSesto in a URI press release. “They’re pretty firm, but sick ones are slimy and mushy and you might see white lesions on them that are eating away the tissue.”
Now, thanks to a $40,000 grant from the Rhode Island Science and Technology Council, scientists from URI, Brown University and Roger Williams University will collaborate to try to find out more about the disease.
Die-offs of sea stars have been known to happen from time-to-time, but this one seems particularly severe, and the disease causing it has not been observed until now.
“Often when you have a population explosion of any species you end up with a disease outbreak,” said Gomez-Chiarri. “When there’s not enough food for them all it causes stress, and the density of the animals leads to increased disease transmission.”
“This one seems particularly severe,” DelSesto said. “And climate change may be making it worse.”
The effect of climate change on the disease outbreak is just one aspect the team will be studying. Other questions they hope to answer include identifying the pathogen causing the disease and whether or not environmental changes have altered the food chain.
There is no threat to humans.
“The outbreak isn’t something people need to worry about contracting because we don’t eat sea stars,” Gomez-Chiarri said. “ And most diseases of marine animals are not transmitted to humans. It’s primarily a worry about the health of the ecosystem and whether the disease is an indicator of something else.”