Saving Sunflower Stars

Though they may not look like it, sunflower stars are voracious predators. Their many arms help them move quickly to catch sea urchins, crabs, snails, and other prey. “They’re pretty much the top dog on the seafloor,” says Hodin. Predators are especially important in kelp forests. By eating the urchins that eat the kelp, sunflower stars keep the underwater forest healthy. Kelp forests provide food and shelter to thousands of species, including fish, birds, otters, whales, and more.

Many kelp forests in the Pacific had been struggling for years. Then, in 2013, sea star wasting disease started spreading in northern California and Oregon. Infected stars first develop white patches on their skin. Then their muscles and other tissues start wasting away. “They essentially melt,” says Hodin. Sick sea stars look gooey and deflated. Not many survive.

The outbreak tore along the coast. For reasons scientists still don’t understand, sunflower stars were hit the worst. Since then, more than 5.5 billion died, and they almost disappeared from the coastal waters along Oregon and California. In 2020, scientists declared the species critically endangered.

Sunflower stars don't look threatening. But they're fierce predators. Their many arms help them move quickly to catch prey. Sunflower stars eat sea urchins, crabs, snails, and more. "They're pretty much the top dog on the seafloor," says Hodin. Predators like sunflower stars are important in undersea kelp forests. Sea urchins eat kelp. Sunflower stars eat the urchins. This keeps the kelp forest healthy. Kelp forests provide food and shelter to thousands of species. Fish, birds, otters, whales, and more live in kelp forests. 

Many kelp forests in the Pacific had been struggling for years. It got worse in 2013. That year, sea star wasting disease started spreading in northern California and Oregon. Infected stars first get white patches on their skin. Then their muscles and other tissues start wasting away. "They essentially melt," says Hodin. Sick sea stars look gooey and deflated. Not many survive.

The disease spread along the coast. Sunflower stars were hit the worst. Scientists still aren't sure why. More than 5.5 billion sunflower stars died. They almost disappeared from the waters along Oregon and California. In 2020, scientists declared the species critically endangered. 

Back in 2019, Hodin got a call from scientists at the Nature Conservancy in California. They wanted to help their local kelp forests by bringing back sunflower stars. But it had been three years since a sunflower star was spotted in the wild in California. They knew the Salish Sea had more survivors and wondered if Hodin could gather some and breed them in captivity.

He knew it would be a challenge: Because sunflower stars had been so common, no one had studied how to raise them in a lab. Hodin didn’t know how often adults reproduced or what to feed baby larvae. But he was willing to give it a shot.

Hodin’s team found 35 adult sunflower stars around San Juan Island and got to work. The first time Hodin bred them in captivity, most of the poppy seed-sized babies died. He spent months experimenting with different foods and tank setups. Hodin discovered that their favorite food was baby sea urchins—but the sea stars also ate each other sometimes! So he had to separate the baby sunflower stars when they reached a certain size.

When the stars reached young adulthood, Hodin’s team gave them names like Muddy and Flapjack. Over the next few years, they raised more than 200 sunflower stars.

Back in 2019, Hodin got a call. It was from scientists at the Nature Conservancy in California. They wanted to help California's kelp forests. Could they bring back sunflower sea stars? It had been three years since one was spotted in California. They knew the Salish Sea had more survivors. The scientists asked if Hodin could gather some and breed them in his lab.

He knew it would be a challenge.  Sunflower stars were once so common, no one had raised them in a lab. Hodin didn't know how often adults reproduced. He didn't know what to feed the babies. But he was willing to give it a shot.

Hodin's team found 35 adult sunflower stars near his lab. Then they got to work. The first time Hodin bred them, it didn't go well. Most of the poppy seed-sized babies died. He spent months trying different foods and tank setups. Hodin discovered that their favorite food was baby sea urchins. But sometimes, the baby sea stars ate each other! So he had to separate them when they grew to a certain size. 

When the stars became young adults, Hodin's team gave them names like Muddy and Flapjack. Over the next few years, they raised more than 200 sunflower stars.