Science Friday - A vast whale graveyard + Zombie sea cucumbers

Episode Date: June 16, 2026

Researchers just published details of a massive undersea graveyard of whales deep in the Indian Ocean. Spanning about 1,200 kilometers (745 miles), it contains whale remains dating back more than 5 million years—and at least five active whale fall sites still teeming with life. Fossil whale expert Nick Pyenson joins Host Flora Lichtman to discuss these findings. Then, marine biologists Rachel Sipler and Sara Jobson join Ira Flatow to describe an unusual discovery in certain species of sea cucumbers: If a foot or tentacle becomes detached, the parts don’t wither up and rot away. Even without a stomach, these parts appear to directly extract nutrients from the surrounding seawater. “Zombie” sea cucumber parts have been observed surviving for more than three years. Guests: Dr. Nick Pyenson is curator of fossil marine mammals at the Smithsonian National Museum of Natural History. Dr. Rachel Sipler is a senior research scientist in the Bigelow Laboratory in East Boothbay, Maine. Sara Jobson a PhD student at the Memorial University of Newfoundland in St. Johns, Canada. Other episodes you may enjoy: Remembering Roger Payne, Who Helped Save The Whales Can A Microbe Conservation Movement Take Off? Transcripts for each episode are available within 1-3 days at sciencefriday.com. Subscribe to this podcast. Follow our show on Instagram, TikTok, Facebook, and Bluesky @scifri and sign up for our newsletters. Got a science question that’s keeping you up at night? Call us: 877-472-4374 Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

Hey, it's Flora and you're listening to Science Friday. Researchers discovered a vast whale necropolis deep in the Indian Ocean, a.k.a. a massive undersea graveyard for deceased whales. Stretching around 745 miles, it contains whale remains dating back over 5 million years. And it's not a dead and quiet place. There are at least five active whale fall sites in the sea. zone, teeming with life. Joining me now to talk about it is Nick Pionson. He studies fossil whales and excavated an ancient whale graveyard in Chile's Atacama Desert. Hey, Nick, thanks for being here. Thank you so much. Really happy to be here. Okay. You were not involved with this new find,

but was it big news in your world? Oh, yeah. I was so happy to see this paper, and it kind of blew my mind for a bit. And there's several reasons for that. One is the incredible logistics it takes to get the scientific infrastructure out into the ocean to find this kind of site. They conducted at least 32 dives to go document the site. And I have expected to hear about these kinds of discoveries because we know about these whale super highways that cross-cut the world's oceans. You're chances of seeing a whale in the ocean is not equal everywhere. Whales seem to prefer certain corridors. I didn't know that. There are whale superhighways. Yeah. And that's a result of decades and decades of work of tracking whales, where they go to feed, where they go to eat to mate,

all through the course of maybe a migration cycle. And you kind of expect to find the remains of those super highways on the seafloor underneath. So there should be places around the world that you expect to find the remains of whales. And I think this is probably one of them. The other thing that's really spectacular about this finding is just the extent. I mean, we're talking about an area that in one linear distance might measure the same distance from New York to Chicago. So imagine driving from New York to Chicago, and there were just whale bones littered all across the highway. That's a bit mind-bending, I think. Can you help me picture it?

Yeah. So they found two different categories of whale sites. They found the remains of fossil whales, and then they also found a whale fall that is kind of like a whole ecosystem that colonizes on the carcass of the remains from a living whale. And from that group, they found baling whales and a lot of other beaked whales. Most of the fossil sites seem to just be beaked whales. I think that the experience the researchers must have had was just coming across whale skeleton after whale skeleton as they cruised in their submersible along the seafloor. And that's why the researchers said, you know, this is a megacite. This is a density that we have not seen anywhere else in the world.

This sounds like this is one of these whale super highways, but is it also like the Bermuda triangle? Why are they dying here? Right. It seems like that there is a preponderance of deathly remains of whales, right? And that's why I think the researchers use the word necropolis to describe the megacite. And I kind of went back and forth about in my head whether necropolis was the right word, because necropolis implies human intent, right, of concentrating remains. It's also a whale necropolis is also a fantastic band name.

So that's out there for somebody to grab. But what we're really seeing is that it's an exposure on the seafloor that has skeletal remains that accumulate over hundreds of thousands of years. I mean, think of it this way is that some of those bones on the seafloor have been exposed sitting there for the entirety of our own evolutionary history. So the geologic time span of our own species is encompassed by those lonely set of bones on the seafloor. So if you have enough time, then you can accumulate a lot of skeletal material. You can think of it like a cave site or like a tar pit. These are places that end up recording a lot of remains from the outside environment, including the bones of animals that happen to live nearby or even in the cave itself or fall into a

carpet. And these will accumulate over a long period of time. And clearly, this is still happening today. That's what those active whale fall sites tell us is that whales are still falling to the seafloor and being colonized and forming entire ecosystems that are supported by the nutrients from their bones. Where does this kind of find rank on a paleontologist's bucket list? I have such a long bucket list of places I want to go. And fossils I would love to collect. I think this created a new category on my bucket list because I didn't realize that we would have a chance of documenting the remains of these super highways on the seafloor. And it seems like because whale fall sites, you know, bring a lot of other animals to the yard, is it possible that there's like lots of other cool fossils to find two to?

I bet there are shark teeth down there. I bet there are parts of smaller whales that are just not easily seen. So you're collecting what you can see from a submersible, and that tends to be the bigger stuff. The researchers report a preponderance of beaked whales. And beaked whales are among the most species-rich group of whales on the planet. And we hardly know anything about them. And I think that's one of the big messages I take away is that if you're talking about being on the edge of scientific discovery, oh my gosh. The seafloor is where it's at. You will find more surprises just like this one, but it takes a bit of effort and knowing where to look. Oh, that's the perfect place to land. Dr. Nick Pineson is curator of fossil marine mammals at the Smithsonian National Museum of Natural History. Nick, thanks so much for talking with me today.

So happy to be here, Flora. After the break, you don't need a graveyard if you never die. Stay with us. Imagine if you were to lose a body part, let's say a toe. You'd hurry to get medical care right, but that lost toe would eventually shrivel up and decompose. But researchers have found that in some species of sea cucumbers, that lost body part may be a tentacle or a tube foot, that part can keep on living without the rest of the organism. So far, they've observed what they are calling zombie sea cucumber parts, living for at least three years.

Pretty wild stuff. Joining me now to talk about it, Rachel Sippler, a senior research scientist in the Bigelow Laboratory, that's in East Booth Bay, Maine, and Sarah Jobson, a Ph.D. student at the Memorial University of Newfoundland in St. John's, Canada, two authors on a recently published report on this phenomena. Welcome to Science Friday. Thank you for having us.

Thanks for having us. You know, you're quite welcome. Let me get right into this because it sounds really weird. It looks like this discovery was sort of. of serendipity made by keen observation, not expected. Take me through the discovery, please. Yeah, so I have to first give credit to one of the collaborators in the paper, Emmy Montgomery, who was a graduate student just before Sarah,

and Emmy was the one to first say, why are there still feet in this space? The feet became detached from the organism, and they stayed in their general state for extended periods of times, days, weeks, months, and really they shouldn't. So in marine systems, they should degrade. Bacteria should attack them, and they should pretty much disappear. That didn't happen. So when M.E. Montgomery discovered that these feet were still here, we wanted to understand why.

And why did they not disappear? Yeah, that's part of the question that we're still trying to discover is what factors within the tube feet and the organism themselves allow them to persist under pretty significant bacterial pressure. Sarah, do these body parts do anything? or they're just sitting there on the glass or the side of the tank? So the tube feet are pretty stationary. They don't move around, but they do restructure and reform a little bit. The tentacles, on the other hand, when they were healing and surviving in natural seawater, they were actually continuing to move around and respond to their natural environment.

It almost looked kind of like they were trying to continue feeding. and when we would poke them or move the water around them, then they would retract into themselves as though they were responding to maybe predator pressure or something like that. So it seemed as though there was still a bit of neural function going on in these tentacles, almost a little bit like thing from the Adams family.

That's why you're calling them zombie parts. Yes, they kind of straddle that line between what is alive and what is dead. Well, let's get into that. a little bit more. Why would they not be alive? Why would they not be dead? Oh, man. I think this is opens up a lot of questions that still need to be explored. And it honestly took us in a lot of maybe philosophical directions because they kind of defy some of those boundaries that we've put on why organisms want to be alive or the evolutionary advantage. The fact that these organisms are

persisting, they're demonstrating some of the key fundamental processes that keep tissues alive, but they don't reproduce, which is something we expect to see in living organisms. And so they kind of exist in the gray zone a little bit. Yeah, I think that the understanding that we can gain from this is pretty impressive. I mean, think about when you have an organ transplant or something like that, you're rushing so that the tissue doesn't die and nothing happens. If we can learn more about how a tissue is able to survive outside of the organism, maybe we can understand how to preserve it for longer for our benefit. How are these body parts, so to speak, able to fight off being eaten, fight off bacteria,

microorganisms in the ocean? I mean, did they have an immune system to fight off infection? Yes. So one of the things that we looked at in this study was the presence of their immune cells, which in sea cucumbers are called selimocytes. And so we used histology to look at the internal organization of their tissues. And we saw that their immune cells were still there. And they were actually migrating through the tissues to specific sites.

So early on during the wound healing and regeneration, the immune cells migrated to the wound site and seemed to be helping with cleaning, degrading tissues and possibly preventing invasion by bacteria and things like that. Now, I know that sea cucumbers have mouths and stomachs. How does a zombie foot or a tentacle part stay alive while not eating? That was one of our questions. So we actually added some nutrients in the form of amino acids. So we added supplemental amounts of that to the water.

And we found that the podia or the tube feet were actually able to take up those nutrients without needing a digestive tract or mouth. So would you say that it's still growing? And you see it expanding and growing, Sarah? So they did grow in size a little bit, but I would say the most striking change was in their appearance. So they went from looking, as you would expect a two foot to look, if you know what those look like, to reforming into a spherical shape. It looked almost like something from outer space after a couple of years because they became perfectly circular and almost transparent around the outer space.

around the outer edge and all of the red pigmentation that the sea cucumber is known for migrated into the center to create this scarlet nucleus. And so we were able to see how these tissues were changing and restructuring their internal tissues to a kind of better suit the life that they were currently living. Were they trying to become the whole animal again or not? It's hard to tell from an early stage, but there's There's no indication from what we can see that they were regenerating into a new sea cucumber, which is, I think, one of the more confounding or bizarre parts of this research is that it's not a form of cloning or fragmentation that we would see in other marine species. It's actually these tissues just finding a way to best survive and best function in their current state as kind of a new biological unit.

And Sarah, you know, this sounds like it was a surprising result. So what did it take to convince you that what you thought you saw happening was actually happening? Absolutely. I think we were all a little, we were just like, how can this be true? This is so bizarre. And it took a long time, I think, to convince ourselves that this is actually what we were seeing. And so we, as Rachel mentioned, we kind of started with just. I mean, seeing how long these tissues will survive in natural seawater conditions.

And then once they were surviving, we're like, okay, well, there must be mechanisms supporting this. So is cellular proliferation happening? Is their immune system functional? How are they fueling their cells? Where are they getting their nutrients from? And I think every new discovery just propelled us into a new question. And even though I think we've learned a lot, it really has just opened up, I would say, multiple careers worth of questions going forward. You know, as a science reporter, we're always taught back in science reporting school to ask this question. So I'm going to ask it because it seems relevant here. What practical value does this research give us? There's a number of different areas of research that will benefit.

I'm thinking of healing and regeneration for damaged tissues, tissue aging and longevity studies, tissue engineering to help keep these tissues alive, stable and functional outside of the body, what we can learn for our own tissues or other tissues. Providing this ethical and more accessible research model. Again, we think of helic cells and all of these different forms of mammalian cells that are harder for researchers to access. So this would give them a different model to use that without those biosecurity or access restrictions. Again, like Sarah mentioned before, the study of a immune.

immune systems. There's just this huge wealth of opportunity for these organisms. You know, I'm struck, Rachel, by in the literature, calling it zombie sea cucumber parts. It's like having fun with it. Does that help communicate what's going on? I think it really does. And we've been using that since the origin of the study. And it really brings life in a little bit of reality to what we're looking at here. And with science, you need a little bit of connection, and this helps us connect to what these really are. It's that dismembered part, the thing from the Adam's family, all of these different connections, this living tissue that is very on brand for a zombie discovery in 2026. Sarah, are you going to be known as the zombie researcher here?

I mean, are you going to study this now? I'm hoping to be done grad school in the next month or so. And as in everything with academia, we're going to pursue funding opportunities to keep working on this and just see where we can take it. I think for me, I would be really interested in looking at what the evolutionary purpose of this type of weird adaptation would be because, as I mentioned, they're not reproducing entities. And so what types of environmental drivers are maintaining this regeneration? So is somebody going to be assigned to watching how long these organisms live? I mean, they're now, what, three years or so? Yeah, I mean, we always have people in the lab keeping an eye on what's going on,

and we try and keep things going for as long as possible, because, as Rachel had mentioned, without people that are making these observations and continuing to study them, we never really know what's going to come out of it. Well, I want to thank you both for taking time to be with us today. Rachel Sippler, senior research scientist in the Bigelow Laboratory, Sarah Jobson, Ph.D. student at the Memorial University of Newfoundland. Thank you both. Fascinating work. Good luck to you. Thanks. Thanks for having us.

This episode was produced by Charles Berkwist. And if you have an unusual observation about the world or maybe a question, we'd like to know about it. Give us a call. The number is 8774-Sye-Fri. That's 877, the number four, sigh-fry. Thanks for listening. We'll see you again. I'm Ira Flato.