(soft upbeat bass music) - [Voiceover] If you were a scallop or muscle, this would be terrifying.

Meet Pycnopodia helianthoides, the sunflower sea star.

It's the largest sea star on earth, boasting an arm span of up to three feet and growing as many as 24 limbs.

Sunflower stars are a keystone species for ecosystems along the West Coast, which means they play a critical role in the surrounding habitats.

But there's a big problem.

Sunflower stars are at risk of becoming endangered and their declining numbers has had a cascading effect on kelp forests.

- It's important to think about these top predators as maintaining the structure and health of a biodiverse ecosystem.

- [Voiceover] These are baby pycnopodia, and the fact that they even exist is a minor miracle.

Through trial and error, scientists had to basically figure out how to do IVF, or in vitro fertilization, for sea stars.

No small task, but Jason Hodin, who runs the world's first pycnopodia captive breeding program, is up for the challenge.

- It's, like, the most enjoyable thing that I could possibly imagine.

Like, being able to see these stars grow from embryos to these incredible larval stages that undergo this incredible metamorphosis.

I mean, this is an amazing thing to be able to witness.

- [Voiceover] For the past three years, they've been meticulously caring for this first generation born in the lab from wild caught parents, and today's the first attempt to see if these lab born stars can successfully breed.

(audience cheering) Something that before now, has never been attempted.

- We are about to select six stars that were born in 2019 and that are now a little bit over three years old, and we're going to attempt to spawn them for the first time.

We think they might be reproductive this year.

All right, let's bring them in.

Bucket of stars.

- Bucket of stars.

- My God, you weren't kidding.

- And the males that spawned last time.

- Okay, these guys are just under 1,000 milliliters, this one is.

- Yeah.

- Come here.

- There we go.

- I really, oh, okay, don't do that.

- The way to spawn a sea star is to inject it with its native spawning hormone, 1 methylamine.

And so we made up a solution yesterday of that.

- Sea stars, from the outside, I couldn't look at one in the wild and say, "This is a male, "this is a female."

They look exactly the same, so you have to rely on when they spawn because that's going to be pretty obvious.

- All right, I would go central on the central disc and don't inject yourself.

Okay, that's good.

And that's injecting in arm four.

- All right, buddy.

- [Voiceover] In just a few hours, if the sea stars are ready, the hormone will trigger the release of eggs or sperm.

- The males will hopefully start to spawn in about an hour and a half, then a bit later, the female spawns.

- [Voiceover] At one point, hundreds of millions of sunflower stars flourished throughout the West Coast, but in 2013, a mysterious disease known as wasting syndrome led to mass die-offs, killing over 90% of the sunflower stars in North America.

- They'll just start, without prompting, losing arms, and this can happen to one arm, to many, the majority of the star even.

- We lost somewhere around 90% of the sunflower stars, which is hundreds of millions of animals.

As horrible as that is, what that suggests is that the ones that didn't die probably had a little bit of resistance to it.

And if two of those stars breed, like the two stars that we breed in our captive breeding program, we think that their offspring are likely to be even more fit in response to the disease too.

- [Voiceover] The goal of the captive breeding program is to raise stars that are more resistant to wasting.

These stars will eventually be released into the wild, and begin a gradual process of rebuilding their population.

But before all that can happen, Jason needs sperm and eggs.

- Well, I mean, there was just the ever tiniest little bit of sperm.

I'm sure he's going to spawn a little more, but you see the cloudiness in that?

We'd like to keep track of who spawns, and by separating the males and females, then we can control the fertilization.

Okay, I'm just going to pick him up real quick.

Trying not to get it spilled in the female tank there.

But I also want to take a quick look at this.

(machine humming) You can see that it's getting concentrated down there at the bottom and I'm just pulling it off up to the part that it's concentrated.

Oh, yeah.

Lots of swimming sperm.

It's a good sign.

Looks like this is a boy too.

- Ariagne's a boy.

- We are, so far, getting only males.

- You kind of need two to tango.

- Yeah, you need two to tango and the backup plan is going to be that tomorrow, I might take one of the adult females and spawn her, so that we can get some eggs.

But it's exciting right now.

I mean, they're clearly reproductive.

They're spawning on cue and it's great.

- [Voiceover] There's another crucial step in the effort to restore sunflower star populations, and it's happening at the Oregon Coast Aquarium.

- We have our oldest and biggest pycnopodia right here.

If I just very gently touch her, she's going to reach up and touch me back.

And this responsiveness is something that we like to see because it indicates that they're doing well.

- [Voiceover] This is Aquarist, Tiffany Rudick, and she's come up with a clever way to treat wasting disease.

- This is one of our seastar treatment patients.

He dropped all of his arms and is now growing them back.

- [Voiceover] The treatment starts with giving the stars in iodine bath to kill harmful bacteria, fungus, and parasites on their skin.

Then they're put in a water solution that contains nutrients and a special probiotic to help the stars heal and regenerate lost limbs.

Last, the water temperature is lowered to 50 degrees, which is ideal for sea stars, but too cold for harmful bacteria to spread.

- That's kind of the really huge benefit of this treatment is they're able to just use their immune system fully for healing and regeneration and to get strong again.

It gives them a unique chance at recovery.

- [Voiceover] Back at Friday Harbor, the lab-raised females still haven't spawned and may need more time to mature.

So Jason's moved to plan B.

- So this is Prospero.

Prospero, as a female, has spawned a couple of times for us in the past.

If she spawns, then we can at least get offspring that are half from the wild and half from our brood stock, which would be the first time that's ever happened too.

So that's still worthwhile.

- No, I just looked, like a minute ago.

- Okay.

- That's so awesome.

- It's sort of building up there.

Prospero is spawning.

Now, we have some eggs that we can use with the sperm that we got from yesterday.

We're about to fertilize, okay?

- Okay.

- Yep.

15, 16, 17, 18, 19, 20.

I think it'll be enough, we can always add more later.

Can't take sperm away, just add more.

- That's what I always say.

(both laugh) - I'm seeing fertilization, exciting.

At least now, we have the capacity for the first time to close the loop on the lifecycle.

In other words, to raise a batch of larvae where at least one of the parents was born in captivity themselves.

So it's pretty exciting.

- [Voiceover] For the scientists, this is a true milestone.

But before they can start releasing stars along the West Coast, one final consideration remains, figuring out whether or not these lab-raised stars can survive in the wild ocean.

- I have 29.

- Sweet.

- Okay, you guys ready?

- Let's do it.

(water splashing) - [Voiceover] This is Joey Oman.

He's the dive lead for the sunflower star breeding program.

Joey's job is to transition the lab-grown stars into the ocean, to see whether they can survive on their own.

By keeping them in cages, he's able to closely track their progress over time.

- So this is ensuring that our captive reared stars don't immediately succumb to wasting.

We do have our eyes on this idea of releasing into the wild, and we want to make sure that the stars that we release out there are fit and that they're going to survive in that context.

- [Voiceover] So why go through all this trouble to begin with?

Why is it so important that sunflower stars survive?

- When you lose pycnopodia from the environment, you are losing the predator that keeps the population in check.

Urchin populations have exploded and they have just been decimating kelp forests.

- The kelp forest ecosystem in the West Coast, it's really worthwhile to think of it as a forest.

It's literally like a tropical rainforest of the ocean.

- Kelp forests are rather important because they create a lot of oxygen and they suck up a lot of CO2.

The hope is that maybe the reintroduction of pycnopodia will help take down the urchin population and help flip that back over to a kelp forest environment.

A species shouldn't have to justify to you why they need to exist.

We've altered the planet in a lot of ways that have made it rather inhospitable for many species, and we've lost a lot of them.

And I think whether or not something is relevant to medical research or to, like, the greater environmental impact, all species deserve to have that fighting chance to continue existing.

(gentle upbeat music) - Getting inspiration for your next adventure.

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