For two years, a mysterious disease has been melting sea stars along the West Coast into a gooey mess. Scientists suspect a virus caused the epidemic, which they call one of the largest marine disease outbreaks ever recorded. But after millions of sea stars died, they are now seeing sea star baby booms in some areas, offering a sense of hope for a comeback.

The purple and orange baby sea stars Moritsch found are about the size of a quarter. She says their size dates them to being born during the mass die off from the wasting disease.

“We’ve seen more babies in the last 12-ish months than we have had in the previous 14 years combined,” says Pete Raimondi, a professor of ecology and evolutionary biology at UCSC. His office overlooks Terrace Point, and Moritsch is a student in his lab.

“Now, that’s not characteristic of all sites, but it is an indication that there is substantial recruitment occurring,” he continues.

...So what’s going on? Experts at NOAA say that the culprit is rising ocean temperatures. (On a call with reporters Wednesday, a NOAA climate expert said that they do not believe the stranding increase is tied to climate change.) The warm temperatures are somehow affecting the squid, sardines and other animals that are the core diet of sea lions, perhaps driving the prey deeper into the water or farther offshore. So when mothers swim off to forage from the Channel Islands, where pups are weaned every year, they are having to stay away longer before they can come back to nurse. With less frequent nursing, pups are losing weight at unprecedented rates, and experts suspect that these weak, under-grown animals are being driven to look for food on their own before they are ready.

“They’re not really capable of diving deep or traveling far,” says Sharon Melin, a NOAA wildlife biologist. “They’re not really capable of being out on their own.” And so the pups are washing up on shore, emaciated.

The root cause of the crisis, officials believe, is the odd wind patterns that aren’t cooling the ocean like they normally do. They aren’t certain of what’s behind the lack of cold winds, but they believe the patterns are creating a ripple effect through the food chain. The sea lions, at the top of that chain, are signaling that bigger things may be amiss among the larger marine food web. “There are a lot of puzzles here that we’re trying to put together,” says Nate Mantua, a NOAA climatologist. “We don’t understand it. It’s a mystery.”