The mass deaths of sea stars off the Pacific coast of Canada and the United States could be part of a cycle that’s occurred in the past, and not a cause for alarm, says a Canadian scientist.

“They’ve been known to have blooms and die-outs,” says Donna Gibbs, a research diver and taxonomist with the Vancouver Aquarium. “It’s the magnitude of this that has everyone shocked.”

Gibbs, who monitors the waters off Howe Sound, B.C., says that over the last few years she’s seen a large increase in sunflower sea stars. But in September 2013, divers noticed that large numbers of sea star species, including the sunflower, were dying off.

Scientists believe that a wasting syndrome, the underlying causes of which remain unknown, is to blame. Gibbs says that the overabundance of sea stars in some areas could have caused the condition to spread quickly. Samples of the dead stars have been sent for testing to determine what is killing the animals.

Meanwhile, Gibbs says she’s noticed the sea returning to normal. She says the sunflower sea star build-up in particular had squeezed out some species that have since started to return around Howe Sound, including other types of sea stars, snails, seaweed and barnacles. Even the sunflower sea star itself could recover, says Gibbs. “This could be healthy. The rock is clean and we’re seeing babies of the sunflower species now. Hopefully they’ll survive and we’ll get back to a normal balance.”

Check out our story from earlier this year to find out how this problem with the starfish was first discovered and see a video showing the sea star disintegrating.

Photo: Courtesy of Vancouver Aquarium

Photo: Courtesy of Vancouver Aquarium

Photo: Courtesy of Vancouver Aquarium