Jason Hodin hauls up a rope that's hanging from a dock in the waters off San Juan Island in the Pacific Northwest. At the end is a square, sandwich-size Tupperware container, with mesh-covered holes in the sides to let water flow through. Hodin pulls off the lid and peers inside at some crushed bits of shell. He points to some reddish-orange dots.
"See that? That little dot right there in front of my finger?" Hodin says. "That's a juvenile sea star that's about a month old."
It's only the size of a poppy seed. But when this baby is all grown up, it could be as big as a manhole cover. That's because this is Pycnopodia helianthoides, aka the sunflower sea star. It's one of the biggest sea stars in the world, with an arm span that can be more than 3 feet across, and it used to be a common sight in the waters off the West Coast.
Now, though, it's critically endangered and is being driven toward extinction by a mysterious, devastating disease.
This is why Hodin and his colleagues at the University of Washington's Friday Harbor Laboratories have spent the last two years figuring out how to raise this species in captivity. It's an act of desperation born out of the hope that someday, lab-grown sunflower sea stars could be reintroduced into places where this species has disappeared.
This voracious predator used to prowl the waters across a nearly 2,000-mile range, from Alaska to Baja California. Their brightly colored bodies — which come in vivid shades of orange, pink, blue and green — would move along the seafloor on as many as 24 arms, gobbling up mussels and scallops and sea urchins. Their consumption of sea urchins, in particular, helped to protect vital forests of kelp, which are home to numerous marine species.
In recent years, however, populations of the sunflower sea star have declined by 80% to 100%. In California, "sunflower sea stars are more than 95% gone," Hodin says. "Some people think that they are entirely extinct in the wild down there. I've heard scattered reports of people maybe seeing a few."
This species seems particularly susceptible to a wasting disease that's hit more than 20 sea star species since 2013. Hodin says the sick sea stars are horrible to behold. "I witnessed it, and it's not pretty," he says. "They really do kind of like dissolve into a pile of goo."
In 2019, Hodin says, the Nature Conservancy approached him about the possibility of setting up a program to breed sunflower sea stars. He'd already been interested in the basic science of sea stars because of the way they are able to transform themselves from bilaterally symmetrical larvae to juveniles with five-sided symmetry. He agreed to try raising large numbers of sunflower sea stars to adulthood, even though no one had tried to do anything like this before.
"For this species in particular, there were very few published efforts to raise them at all, even through embryo or larval stages," Hodin says.
He didn't know the answer to some of the most basic questions, such as what did this species eat early on? And how fast could it grow?
"Nobody knows how to age a sea star, so you see something in the wild and you have no idea how old it is," Hodin says. "It could be 2 years old. It could be 50. It could be 100."
His team started by taking some sunflower sea stars from the wild. About 30 of these giants now live outside the lab in large, burbling tanks.
"I didn't really anticipate how exuberant their behaviors are," Hodin says. "You get to know them, and you get to know them individually. We noticed early on that we could tell them apart by their color patterns. And we gave them names."
A lot of their names are linked to their colors. Prince, for example, has arms with tips that are purple.
"This here's Deep Blue, and she's our biggest," researcher Fleur Anteau says as she feeds the sea stars by gently tucking mussels under their arms. "Some of them, when I open the cage, will basically really start moving their arms to the surface, like Olga here. Some of them are a little shyer."
Even the shy ones suddenly come to life once they clutch a mussel. They hunch over the prey so they can swallow it whole. "When food comes, then you really see the predator come out," Anteau notes.
Pointing to the red eye spot at the end of each arm, she adds, "They're looking at you. They don't have eyes like us, but they can see a light-and-dark kind of vision."
This lab has figured out how to get sperm and eggs from the wild-caught adults and grow up their offspring. The oldest sea stars they've produced are now nearly a year and a half, and they are about 3 inches across.
The lab only has about a dozen young sea stars that have reached this stage. But considering how little was known at the start — and the fact that they had to work out their techniques during a pandemic that restricted who could go to the lab — Hodin says he feels lucky to have gotten that many.
"We're assuming that by next year, they might be reproductive, based on ones that we've seen in the field," Hodin says. "It's good news that they can grow relatively quickly."
Having learned the tricks needed to raise these sea stars, the research team's new goal is to produce up to 1,000 more young stars. The lab is full of glass pickle jars that contain larvae, and food containers that hold the poppy seed-size juveniles.
Hodin says that first, lab-grown sea stars could be put into the local waters, where their parents came from, to test how well they fare in the wild. If that goes well, it might be possible in the coming years to try to restore populations off the California coast.
But the danger of sea star wasting disease could still be out there.
"I would say at the outset that it's critical to understand more about what's killing them before trying to put them back," says Drew Harvell, a professor emeritus with Cornell University who is also a researcher at the Friday Harbor Laboratories.
Currently, she says, scientists disagree on the nature of the killer. Some blame an infectious agent, such as a virus, while others point to warming oceans or other environmental changes.
"It's extremely controversial," says Harvell, author of a book called Ocean Outbreak: Confronting the Rising Tide of Marine Disease. She believes there's a lot of evidence that sea star wasting disease is infectious.
This month, she and her colleagues are starting new lab experiments to test that idea. In a fish pathogen lab, extracts from sick sea stars will be injected into seemingly healthy ones. She'll be using sunflower sea stars since they are so susceptible.
"These are difficult experiments to get to run consistently, and so if you try to do them with a species that is somewhat resistant, sometimes just nothing happens," Harvell says.
Even if scientists never are able to figure out what causes this illness, she says, eventually it could still be worth trying some kind of reintroduction of captive-bred sea stars to the wild.
"At some point we would just have to probably go forward," Harvell says, "even though scientifically that wouldn't be the very best plan."
Hodin wishes he knew whether the sea stars his lab is raising are susceptible to the disease. He's constantly on the lookout for any signs that his beloved animals are falling ill. "We hope they don't get it obviously," he says.
He uses a pair of tweezers to tenderly feed a tiny mussel to one of the young sea stars. It curls its arm around the treat.
"Their adult-like behaviors are starting to emerge at these small sizes, and that's been really fascinating to watch," says Hodin, who adds he feels a deep attachment to all of the animals that he's raised. "I think of myself as their foster parent. I'm caring for them and trying to optimize their growth and watching them grow."
He says he even dreams about them. Just the night before, he'd dreamed of being surrounded by water in a house-size version of one of their tanks.
A MARTINEZ, HOST:
The sunflower sea star can be as big as a manhole cover. It could also have up to 24 armed. Now, the species used to be common off the west coast of the United States. I stress used to be because in recent years, it's nearly disappeared, the victim of a deadly wasting disease. NPR's Nell Greenfieldboyce went to an island off the coast of Washington to see how researchers are trying to save it.
NELL GREENFIELDBOYCE, BYLINE: Jason Hodin hauls up a rope that's hanging off a dock into the water. At the end is a square, Tupperware container, the kind you might use for a sandwich. This one has holes cut into the sides that are covered with a fine mesh to let water flow through. Hodin pulls off the lid. And we peer inside. There's some crushed shells and some tiny, reddish-orange dots.
JASON HODIN: Like that guy right there. See that little dot right there in front of my finger? That's a juvenile sea star. He's about a month old.
GREENFIELDBOYCE: It's the size of a poppy seed. Baby sunflower sea stars like this one are what Hodin and his colleagues are figuring out how to raise here on San Juan Island in the Pacific Northwest at the University of Washington's Friday Harbor Labs. In the wild, sunflower sea stars are being wiped out. For example, Hodin says, in California...
HODIN: Sunflower stars are more than 95% gone. Some people think that they're entirely extinct in the wild down there. I've heard scattered reports of people maybe seeing a few.
GREENFIELDBOYCE: The culprit is a mysterious wasting disease. No one knows what causes it. Since 2013, it's been hitting a bunch of sea star species hard on both the West and the East Coast. Hodin says the sick sea stars are horrible to behold.
HODIN: They really do kind of, like, dissolve into a pile of goo.
GREENFIELDBOYCE: And sunflower sea stars seem to be the most affected. So in 2019, the Nature Conservancy approached Hodin about setting up a program to breed this species in captivity with a goal of someday reintroducing it into locations where it's disappeared. He and his colleagues first took some sunflower sea stars from the wild. About 30 of these giants now live at the lab in burbling outdoor tanks. Researchers like Fleur Anteau recognized them as individuals.
FLEUR ANTEAU: This here's Deep Blue, and she's our biggest.
GREENFIELDBOYCE: A lot of their names are linked to their colors. Like Prince has arms with tips that are purple. These sea stars can be orange, pink, green. The colors are so bright, they almost glow like the creatures are lit from within.
ANTEAU: So some of them, when, you know, I open the cage, will start moving their arms to the surface, like Olga here. And some of them are a little shier.
GREENFIELDBOYCE: Even the shy ones suddenly come to life as she tucks tasty mussels under their arms. They hunch over the prey so they can swallow it whole.
ANTEAU: When food comes, then you really see the predator come out.
GREENFIELDBOYCE: Sunflower sea stars are predators, voracious ones. They normally crawl along the sea floor and gobble up sea urchins, keeping their populations in check and helping to protect kelp forests. This lab has figured out how to get sperm and eggs from the wild caught adults and grow up their offspring in the lab. The oldest they've produced are nearly a year and a half. They're about three inches across.
HODIN: We're assuming that by next year, they might be reproductive. Based on ones that we've seen in the field, the smaller ones that we know are reproductively mature.
GREENFIELDBOYCE: Hodin's lab is working to produce hundreds of young sunflower sea stars like these. He says, these could first be tested in local waters, where their parents came from, to see how well they fare in the wild. Then someday, maybe they could go into places where sea star populations have vanished. But the danger may still be out there.
DREW HARVELL: I would say at the outset that it's critical to understand more about what's killing them before trying to put them back.
GREENFIELDBOYCE: Drew Harvell is a research scientist at Friday Harbor Labs and professor emeritus at Cornell University. She thinks the cause could be an infectious agent. Other scientists blame warming ocean waters or other environmental changes.
HARVELL: It is extremely controversial. There is not agreement.
GREENFIELDBOYCE: She's starting new lab experiments this month to test the idea that it's infectious. Extracts from six sea stars will be injected into seemingly healthy ones. She'll be using sunflower sea stars since they're so susceptible. Meanwhile, at Hodin's lab, he's constantly on the lookout for any signs that his beloved animals are falling ill. I watch him use a pair of tweezers to tenderly feed a tiny mussel to one of the young ones. It curls its arm around the treat.
HODIN: They're our foster kids. And we're responsible for them. We take a lot of care in trying to make sure that they stay alive.
GREENFIELDBOYCE: He says he even dreams about them. The night before, he dreamed of being surrounded by water in a house-sized version of one of their tanks.
Nell Greenfieldboyce, NPR News. Transcript provided by NPR, Copyright NPR.