Short Wave - Sea Camp: Is Better Human Health Hidden In The Sea?

Episode Date: July 21, 2025

For this week's Sea Camp, we're diving below the ocean's surface to explore the sunlight zone, the portion of ocean that's 0-200 meters deep. Here, we zoom in on some spineless inhabitants envied for their "superpowers." Marine biologist Drew Harvell tells us about stealthy sea slugs, sea stars with super strength and life-saving sponges. Also, exciting news!! WE HAVE A NEWSLETTER! It lets you go even deeper with the marine research each week of Sea Camp. Sign up here!Want to hear more stories about underwater marvels? Email us and let us know at [e-mail] to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey everyone, Regina Barbara here. It's Monday, which means sea camp, our summer series where we share science stories from the ocean diving a little deeper each week. And today, we're finally going to take our submersible downwards to the sunlight zone, also known as the epipelagic zone of the ocean, which is zero to 200 meters. That is where a sunlight is penetrating the ocean. This is marine biologist Noel Bolin, who's worked for the National Oceanic and Atmospheric Administration, or NOAA. Noel is going to be our ocean zone guide for the rest of the series. And the thing that you need to know about the sunlight zone is that.

The things that happen at the surface are very important for every zone. And that's the photosynthesis that happens. Courtesy of phytoplankton, the plants of the sea. They eat sunshine, poop out food for other critters, and generate oxygen. The ocean makes about half of Earth's oxygen and plankton are responsible for a big share of that. So this zone is essential to our planet's health. And it's a place that Drew Harville has seen up close, as a diver who studies marine invertebrates, creatures without a backbone, who have been around for a long, long time.

They've been on our planet for over 600 million years, so they are some of the most ancient of our animals. Drew so fascinated with these spineless creatures of the sunlight zone that she wrote a whole book about these ancient creatures and how their long evolutionary histories have led to some interesting biology. I think of them as kind of biological impossibilities, sort of like, you know, Superman flying or having invulnerable skin, right? For an animal to photosynthesize, that's legitimately a superpower. And it's not the only one. Across these marine invertebrates, there's a whole bunch of superpowers. everything from regeneration to super strength, and even stealing other animal's abilities. Drew says understanding these animal's superpowers not only helps researchers understand the rules of life, the lesson scientists learn from them can transform our medicines.

Every one of the ones that I talk about in my book also has an important application for humans. So today on the show, the strange world of the ocean's spineless creatures, what their ancient superpowers are, and how they continue to inspire human human. human innovation today. I'm Regina Barber. You're listening to Shortwave Sea Camp, the Ocean Science series from NPR. Okay, Drew, we're talking about the superpowers of marine invertebrates from your book, The Ocean's Menagerie. And we're going to talk about a few starting with sponges, which I have trouble imagining. What should I imagine? They're amazingly beautiful. They come in all colors and sizes and shapes from vases to runners to huge barrel sponges and they're brown and yellow and green and red and

purple. That's amazing. And so, I mean, I just get lost when I'm diving just watching them because they're so beautiful. And, you know, functionally, they seem to be very, very simple. But then when you look deeper, they have amazing functions and sponges have been of great interest to natural products chemists because it was found that the highest hit rate for anti-cancer drugs was from tropical sponges. Oh, wow. We thought the sponges themselves made the chemicals, but we've learned that often it's the bacteria, particular species of bacteria that are housed within the sponge that actually do the chemical synthesis of these compounds. Can you give me an example? I love this one because a sponge that's bright green, it's in the inner tidal everywhere, halocondria panacea, very common.

It houses a strain of streptomyces bacteria that produces a chemical, and that is now being used in clinical trials for a whole range of different cancers, melanoma, pancreatic cancer, and renal cancer. It's being used now. It's being used now. They don't actually pull it out of sponges now. They've actually learned how to create a synthetic derivative. I could go on and on.

And I kind of do in the book, I talk about quite a few examples of cancer drugs that have actually been discovered and produced from sponges. Let's talk about sea slugs next. Introduce us to these critters. What should we know about sea slugs? Oh, my God. Sea slugs are just, they're the most enchanting of the environment. vertebrates in many ways, just because they're a ridiculous circus of colors and shapes. You know, black backgrounds with lime green stripes and polka dots or yellow or pink.

They have these beautiful projections that look like flowers all over their backs. I mean, I think everybody who's seen a neuterbrank falls in love with it just because they're so beautiful. A neuterbank being like another name for sea slugs. Right. Yeah. And I've learned sea slugs are a relative of snails, but instead of having a shell, they have these like chemical defenses in which they can eat other animals and steal their powers. Can you tell me more about like one of those? We have a neuterbank that lives in the Pacific Northwest that eats sea anemones.

And when it eats the sea anemone, it uptakes the stinging cells that sea anemones use in their. own defense. They select the immature stinging cell so they don't explode when they're eating them. They pass them all the way through their digestive system and into these little packages on their back. The stinging cell completes its development and is then used as a harpoon by the neuterbrank. Wow. And the diversity of this particular group of neuterbranks that does this is very high. They've been very successful, particularly in our shallow waters in temperate and tropical ecosystems. So the beauty of the bright colors is a warning to fish and other predators that don't eat me. I'm dangerous.

I've got explosives and I'll use them. It's almost as if I were to eat a venomous snake, then somehow I could have venom or something like that. So like what lessons can humans learn from that? Yeah, I think the lessons we can learn from the ability of neuterranks to uptake these foreign organs from other groups is in transplantation surgery. It's very hard for us to transplant kidneys, for example, even among different humans, let alone what we try to do from pigs to humans. And the way we do that now is we try to suppress our immune systems. That's not what neuterranks are doing. They're playing around with the recognition process.

And so it strikes me that there's a real opportunity there to really think a little bit outside the box about other ways to go in and optimize our transplantation surgery. All right. Last but not least, my favorite. Maybe yours are C-stars? You know, Gina, I think we share that. Okay. They are certainly one of my favorites because, I mean, first they're like Martians.

They have multiple arms. They have thousands of tube feet for running around. They have eyes on each end of each one of their arms. Yeah, all their arms are heads. I remember doing a story about that. Right. Yes. Yeah.

And so, you know, just as an animal, they're very, very strange. And yet the thing that just as a marine ecologist blows my mind is they're incredibly important ecologically. We think of C-Stars as ecosystem engineers because of their power. They're predators. So they eat prey and they eat a lot of their prey, whether it's muscles or clams or sea urchins. Recently, we've been studying one that lives in deeper waters that used to eat all the urchins and control them, but it was decimated by a huge outbreak of disease. I kind of call it the COVID of sea stars because it affected...

It's the wasting disease, right? It's the C-SER wasting disease and it affected over 20 species in addition to the sunflower star, which is the biggest and fastest in the world. I mean, this thing is three feet across. It's huge and it eats a lot of urchins. When you remove all those sunflower stars, the urchins explode and they've decimated our kelp meadows. And so along the entire west, coast from San Diego up to Washington, we've had declining kelp beds partly due to the removal of just

this one species of sea star. And weirdly, for such a big, powerful critter, it was the most susceptible to this disease. And so it's now on the endangered species list. And we've been working for a decade on a recovery program for it. I really like this. You're talking about how these sea stars, they're eating these urchins. They also eat a lot of clamps. So how are C-Stars doing this? The trick, the superpower, is that it takes them a long time and they can hang on without spending much energy.

And they hang on because they have hundreds of two feet, which are like little suction cups that grip incredibly strong. And then the other part of the superpower is their smart skin. they can basically crosslink the microtubules in their skin to make it stiff under nervous control. And then hold that without it costing them anything. And so that's how they win by hour after hour just hanging on and pulling until the clam is opened. So what could humans do with this superpower of like neural control? Well, there's been a lot of interesting research trying to use the ideas in the smart skin

of C-stars and C-cucumbers in tendon replacement therapies because of the ability to change under neural control. So all of these organisms, and they tend to be invertebrates that have these so-called smart tissues, are a lot of interest in transplantation therapy. In the epilogue of your book, you write, the most precious resource on our planet is not oil or metal. It's the deep secrets that string our web of life together. What would you like to see in the future in how humans care for the ocean, like in honor of the statement? You know, I think that the first step is to try to help people understand just the incredible wonder of these resources and their extreme value. and then from there to take the next step of protecting them.

These spineless invertebrates have been on our planet for over 600 million years. They're phenomenal adaptations to change to a changing climate. There are secrets and mysteries that they have solved that are going to be of a lot of use to us. Thank you so much for talking with me today, Drew. I had a wonderful time. Thank you. This has been a really fun session, Regina. I loved it, too.

Drew Harvel's book, The Oceans Menagerie, is out now, where you can read about other invertebrates like jellyfish, octopi, giant clams, sea fans, and corals. And if you like Nudabranks, check out our past episode all about these fascinating creatures. We'll link it in our show notes. Shortwavers, if you want to go deeper with Seacamp, by learning and seeing bonus content and even getting fun puzzles,

sign up for our special limited run newsletter. It's at npr.org slash Seacamp. This episode was produced by Burley McCoy. It was edited by our showrunner Rebecca Ramirez and fact-checked by Tyler Jones. The audio engineer was Jimmy Keely. Beth Donovan is our senior director and Colin Campbell is our senior vice president of podcasting strategy. I'm Regina Barber. Thank you for listening to Shortwave from NPR.