Ed Gullekson / Scientific Progress
Cutaneous lesions are the first sign that something is wrong. Then the limbs fall apart and the body collapses and collapses as soon as it liquefies. Eventually, what once was a sea star is just a puddle on the ocean floor.
Since 2013, the starfish loss disease has killed so many starfish along the Pacific Ocean that scientists say it is the largest epidemic of disease ever seen in wild marine animals. Where dozens of stars were, the divers reported not seeing any.
And while the epidemic itself is a naturally occurring phenomenon, newly published research suggests that climate change can worsen the mortality of the disease.
"What do we think that hot water anomalies cause these starfish to become more susceptible to an existing disease," says Joe Gaydos, University of California Science Director, Davis & SeaDoc Society and one author of today's study in the journal Scientific progress.
He and co-authors analyzed the data gathered by divers and found that divers were less likely to see living marine stars when the water temperatures were abnormally high.
"Thinking that the warmer water temperature may cause the animals to have a more rapid illness, or make them more sensitive, it's like one and two strokes," says Gaydos. "It's a little nervous."
Worldwide, temperatures on the surface of the sea are steadily increasing as the Earth heats up due to climate change caused by humans.
The study has not explored why warmer water can cause marine stars to be more susceptible to disease. The authors assume that a relatively simple animal immune system may be weaker when sea stars get worse.
Same dive survey data also confirms previous findings: that mass starvation of marine stars causes a cascade of further ecosystem changes. Sea urchins that starfish usually eat will proliferate with abandonment. All the rocks that were once covered by the sea stars are now covered in the apocalypse.
Keeps eating algae.
"We see these whales where barley passes and they eat all the kelp," says Gaydos. Kelp forests, like tree forests, are the place of many different species that can be lived and fed.
"We have higher biodiversity when we have more lashes, so the cascade begins," he adds. "If you looked at the mainland, it would be almost like resolving the forest."
It is unclear whether the sea star population will recover in the coming years. Research published last year suggested that some sea stars might be able to survive the disease, offering the hope that the animals will bounce back over time.