Science Friday - DIY Masks, Neanderthal Diet, Symbiotic Worms. April 3, 2020, Part 2

Episode Date: April 3, 2020

During the global COVID-19 pandemic, hospitals across the country are running low on PPE—personal protective equipment. This includes masks, gowns, face shields, and other important gear to keep healthcare workers safe. These supplies are the first line of defense between healthcare workers and potentially sick patients. Cloth masks are usually only advised as a last resort for healthcare workers, but an increasing number of hospitals are seeking them out. Some hospitals, including Barnes-Jewish Hospital in St. Louis—the largest hospital in Missouri—are anticipating a tsunami of COVID-19 cases in the weeks ahead. To get ready, it’s watching and taking lessons from the experiences of hospitals in coronavirus hotspots, like New York City. One big example is turning to homemade cloth masks to fill oncoming PPE shortages. A homegrown effort called the Million Masks Challenge has sprung up amidst the crisis. Volunteers are pulling out their sewing machines and extra fabric to make masks that are sent to healthcare providers. And a new website, GetPPE.org, has launched to connect crafters with hospitals across the country that are asking for homemade face masks. Joining Ira to talk about the PPE crisis and how hospitals are preparing are Rob Poirier, clinical chief of emergency medicine at Barnes-Jewish Hospital and Jessica Choi, founder of GetPPE.org. Why did Neanderthals disappear so quickly after the arrival of early modern humans in Europe, 40,000 years ago? Paleoanthropologists have long wondered whether it was some inferiority that allowed our ancestors to outcompete with Neanderthals for resources—whether that was intelligence, complexity, or some other measure of fitness.  Over the last two decades, the image of the dumb, primitive Neanderthal has broken down. Researchers have found evidence of Neanderthal jewelry and art in European caves, as well as signs they may have buried their dead. But the question remains: Why, when human ancestors finally made it to Europe, did Neanderthals vanish? One persisting theory is that getting Omega-3 fatty acids from diets rich in seafood enabled human ancestors to develop more advanced brains than their Neanderthal cousins. Stashes of fish bones and shells in South African caves have been taken as evidence that early modern humans ate from the sea—and until now, there’s been no evidence that Neanderthals in Europe also did so. But, in a seaside cave in Portugal named Figueira Brava, researchers writing for the journal Science last month found a treasure trove of fish bones, mussel shells, and other remnants of dining from the sea—all older by tens of thousands of years than the first arrival of early modern humans in Europe. Lead author João Zilhão explains how this find expands the growing picture of Neanderthals as complex, intelligent hominins. About 1,800 meters below the ocean surface off the western coast of Costa Rica, methane seeps dot the seafloor. These are places where methane and other hydrocarbons slowly escape from beneath the earth’s crust. Like more well-known hydrothermal vents, methane seeps are home to an unusual array of wildlife, relying on the seeps’ enriched chemistry for energy and nutrients. Writing this week in the journal Science Advances, researchers describe two species of tube worms that live in a symbiotic relationship with methane-oxidizing bacteria that live on their crowns. The researchers collected some of the worms via deep-sea submersibles and then exposed them to carbon-13-labeled methane, showing that the worms were able to assimilate the methane into biomass. The team believes that the symbiosis allows these worms to rely on methane for much of their nutrition. Shana Goffredi, an associate professor of biology at Occidental College in Los Angeles and one of the authors of the report, explains the research and what remains to be learned about the environment around these undersea methane seeps. Writing this week in the journal Science Advances, researchers describe two species of tube worms that live in a symbiotic relationship with methane-oxidizing bacteria that live on their crowns. The researchers collected some of the worms via deep-sea submersibles and then exposed them to carbon-13-labeled methane, showing that the worms were able to assimilate the methane into biomass. The team believes that the symbiosis allows these worms to rely on methane for much of their nutrition. Shana Goffredi, an associate professor of biology at Occidental College in Los Angeles and one of the authors of the report, explains the research and what remains to be learned about the environment around these undersea methane seeps.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Iroflato. A bit later in the hour, we'll talk about how some hospitals are preparing for an unexpected flood of patients and how they're dealing with a shortage of personal protective equipment. Just a note, we won't be taking calls during this recorded hour. Up first. Since they were first discovered, Neanderthals, our much maligned ancient cousins, have been cast as inferior. After all, they quickly disappeared from Europe after the arrival. of human ancestors from Africa 40,000 years ago. But over the last couple of decades, the stereotype of the dumb, primitive Neanderthal has been broken.

For example, jewelry and art have been found in caves, all too old to belong to anyone but Neanderthals. And then there's the fact that they interbred with human ancestors and traces of their genetic material live on in our genes. Yet the big question remains. Where did they go? Why, when human ancestors finally made it to Europe, did Neanderthals vanish? One persistent theory? Omega-3 fatty acids from a seafood diet of our human ancestors allowed them to develop more advanced brains than their Neanderthal cousins. But here's where things get interesting. Because in a cramped cave in Portugal, named Fagira-Ber. Brava. Evidence has been discovered that Neanderthals 2 ate from the sea. The news was published in the journal Science Friday producer Christy Taylor spoke to Dr.

Zhao Zalau, a research professor for the Catalan Institute for Research and Advanced Studies at the University of Barcelona in Spain. Welcome to Science Friday. Hi, good morning or good afternoon or good evening, wherever you are, depending on the time zone. So the first thing I want is for you to take us to this cave. What is it like there? The cave is at the edge of the sea these days.

So when you're there, you're at the edge of the terrace in front of the cave itself. There's a five-meter step, and the sea is just down there. And you can bathe. You can watch the fish and the dolphins swim by. But it's actually a bit misleading. an image that is a bit misleading if you want to think about the site in terms of what it looked like 100,000 years ago when it was used by Neanderthals. At that time, the sea level was lower, and as a result, the shore was some distance away, between 750 and 2,000 meters away. So you have to picture the site as being halfway on a side.

on a slope along the side of something like a Norwegian Fjord. And like you said, that cave was once occupied by Neanderthals. So you went there looking for more evidence of their lives? Yeah, what triggered this, our project was that a previous investigation at this site had returned to radio combatants suggestive of the site being, being inhabited by Neanderthals as recently as 30,000 years ago. And this was an interesting scientific problem because if true, it would represent a persistence of Neanderthals in our part of the world for about 10,000 years longer than elsewhere in Europe. So we were intrigued by this

and decided to build a project, you know, aim that proper dating of the site. And so it was in the process of this that we realized that the part of the site that had not yet been excavated, that was extremely rich in the remains of marine foods. So when the first dating results that we obtained using the different method, uranium series, showed that the site was of last interglacial age, so that it was contemporaneous with the famous middle stone age sites of South Africa like Blombos, Claesus River, and others. You said this dates to the last interglacial. How long ago exactly was that?

The last interglacial is a period of broadly similar climate to the present, which began about 135,000 years ago and ended about 72,000 years ago. It's a long period of time, about 60,000 years. Our site was occupied towards the end of this period between about 86,000 years ago. On land, the environments were pretty similar to present time. So a Mediterranean landscape as we have today. You mentioned this trove of marine food, including a shark vertebrae, which was the first one, the first bone that you found.

How did you know that this was a significant finding? People in places like Southern Africa at this time had been harvesting seafoods in significant amounts, particularly limpets, muscles, and also doing some seal hunting and some fishing. But this was not known in Europe. And because the people living in South Africa at this time are, designated as early modern humans. Whereas in Europe, we are talking about the Neanderthals, who for most people are, you know, like at that end

and a non-fully human, at least, side branch of human evolution. This was not known, okay? And so the hypothesis was put forth by some colleagues, and this is a hypothesis that became very influential, show that it had been the consumption of marine foods because they are rich in fatty acids like omega-3 and such stuff that would have favored the development of brain tissue and somehow resulted in higher cognitive abilities among the people,

so-called early anatomically modern people living in southern Africa. African. And as a result of these enhanced cognitive capabilities, they would have been able to grow in population numbers. Their societies would have become more complex. Their technology evolved faster and to higher levels of efficiency than elsewhere in the world. And so these populations as a result expand. And because they are superior, eventually wipe out everybody else as they expand to Europe and Asia by everybody else, obviously, including the Neanderthals. For Neanderthals to feed on marine resources was a key aspect of this model. And what we have shown, and this is why as soon as we started finding lots of fish remains and large crab remains, it became obvious to us,

that this was an artifact of sampling. And what this tells us, is that as often is the case, absence of evidence is not evidence of absence. You just have to look in the right place and what he thought did not exist or could not exist, in fact, does. You know, so this business of consumption of marine foods cannot serve as an explanation for what happened when people of ultimate African origin began to spread into Eurasia. If there were no fundamental differences between these two groups of human ancestors, do you think we'll ever figure out why they died out? So we're talking of a population imbalance in terms of numbers of like one to 100. For each Neanderthal living in Europe, there would be 100 Africans.

There were much less people in Europe than in Africa, but there are very few people everywhere anyway. Okay. So as soon as that is the situation, the different phenotypes maintain their characteristic features. Neanderthals continue being Neanderthal. People living in Africa continue to be whatever they, you want to call them, right? But as soon as populations on both sides grow along the frontiers or the boundaries that existed before and across which gene flow always existed, even if in limited amounts. Exchange of all kinds become more frequent and more intensive. What you had before as two reservoirs effectively merge into one. And when you do that, you know, and the imbalance is 100 to one,

what's going to happen to the one? It's going to be absorbed. That's what happened to the Neanderthals. They did not die out. They were incorporated in the last. if you want to call it that way, modern human population that as a result, that formed as a result of these of these admixture events. And that is what 70% of their genome is still around. Last question. And that's just what is your dream find? You know, what is the cave or other

site that you would love to unearth? Like what's the data in there? What does it tell us? us, what, what are the bones, what's in there? I've been fortunate enough in the course of my professional career to have found the earliest anatomically modern humans in Europe. I excavated the best air cuas in Romania where we found these fossils that have been subsequently studied by geneticists and before the burial of the Lagarvalio child in Portugal, which was actually the first hard evidence for a mixture between Neanderthals and modern humans published 22 years ago already. And I've been involved in the dating of

cave art showing that Neanderthals were cave artists and now this business with the marine foods, I don't think I can, I have the right to expect anything else. Satisfied. more than satisfied. I consider myself extremely lucky to have been involved in these findings. Well, congratulations, and thank you so much for being with us today. My pleasure. Thank you for your interest and attention. That's producer Christy Taylor, speaking with Dr. Zhao Zalau, a research professor for the Catalan Institute for Research and Advanced Studies. He's based at the University of Barcelona in Spain.

When we come back, we'll hear how hospitals are gearing up for the wave of coronavirus headed their way and how they're facing a shortage of PPEs and welcoming homemade masks. Stay with us. This is Science Friday. I'm Irafledo. Due to COVID-19, hospitals across the country are running low on PPE. You know them as personal protective equipment. This includes the masks, the gowns, and those little boot.

that cover shoes. PPE is important because as the first line of defense, health care workers have, between themselves and potentially sick patients. Currently, Missouri has reported over 1,300 cases of COVID-19. Barnes Jewish Hospital in St. Louis, the largest hospital in Missouri, is anticipating a tsunami of cases to arrive in the next few weeks. And to get ready, it is watching and taking lessons from the experience. of hospitals in coronavirus hotspots like New York City. Joining me today to talk about how his hospitals preparing for a PPE shortage is Rob Poirier, clinical chief of emergency medicine at Barnes Jewish Hospital and the Washew School of Medicine in St. Louis, Missouri. Welcome to Science Friday, Rob.

Thank you, Ira. Give us the status of coronavirus in your region? Sure. So each day we're beginning to see more patients with COVID-19 showing up in our emergency department. Currently, we're seeing about 40 to 60 patients a day. This is kind of a little bit of the lull before the storm. We see what's happening on the coast. Of course, we're very concerned.

But it is giving us some time, crucial time, to prep and get ready and make sure we can do the best job we can. for our community. And that's what I wanted to ask you about, how do you actually prep? You see the storm on the horizon. You see it coming. What does the hospital do? So it's really getting out the education and also making sure our staff feel comfortable working in the emergency department. And a big part of that is making sure they feel comfortable with the PPE or the personal protective equipment that they're given because that PPE not only protects us as health care work, and we don't want many getting sick. It also protects our families, our colleagues, and our coworkers, and definitely protects the patients.

So how do you make sure you're going to get enough of it? I mean, what are you doing for that? Yeah, that's the biggest concern. And we have a lot of PPE on order. And most hospitals purchase through what are called GPOs or group purchasing organizations. And they've run out a lot of their supply that they get. from the major national wholesalers and companies from in the U.S. and around the world, a lot of those supplies are now being diverted to the coast and where the breakouts are.

And so our orders are going unfilled at the moment. So what do you do to make up for that? I mean, do you have to recycle or are you planning on recycling some of the PPE that you have? We do. So we have to conserve and reuse PPE. We are following the CDC guidelines, which are different. than what we normally follow because this is a pandemic and with the shortages of the PPE. So we're now learning how to reuse the PPE.

So for example, the N95 mask, we have to reuse that mask until it gets soiled until it's no longer functioning well. We don't get a good seal with it. What does visibly soiled mean? What does it look? look like? So that will start seeing maybe there'll be blood on it. If there's mucus on it, if somebody coughed and sneezed on us and mucus came out. So we have to use the device until we see that it's visibly soiled. We know that if we changed this PPE out between every single patient, we would, with the number of patients we're seeing, the number of staff we have working, we would quickly run out of the supplies in probably a couple of days.

By conservation strategies and reuse strategies, we can extend the equipment we have for several more days until we get a reshipment or a new supply comes in. Speaking of a new supply, is your hospital accepting homemade masks? We are accepting donations from both industry and public in the public. We are accepting homemade masks, but those cannot be used as our primary protection for PPE. We're still mandated to use the PPE that's certified and approved by the CDC and FDA. But we always want to have a backup. If for some reason we run out of all the hospital supplies, we would definitely use the homemade supplies if it came to that.

What is the morale at the hospital like? Is it like on a war footing? You can hear the guns in the distance and you're waiting for it to attack? Yes, we are banding together. In the emergency department, we face crisis every day, every shift. So we're used to working in high-performing teams under a lot of stress and pressure. We are doing the best we can to keep morale up with all the staff members. You need to make sure that you give them the confidence that they can do their

job safely and appropriately as well. I know that hospitals watch the goings-on of other hospitals and how other hotspots have handled this crisis. What have you learned? What do you watch at, let's say, New York or Detroit or other hotspots? What does your hospital staff and what do you learn about how to deal best with this? What are the lessons there? I think we're learning that cohorting Some of the patients is more helpful. So COVID and COVID-related patients trying to put them, if you're working in a large emergency department, putting them in certain parts of the emergency department, making sure the staff in that area, the emergency department have all the supplies they need and the supplies are close by for when emergencies come in.

We're learning how to better handle what we call aerosolizing procedures. These are procedures where the virus can be aerosolized or put in very fine particles in the air. And we're working on using different equipment and using different techniques when we have to intubate patients or put airway tubes into their lungs. That's a point in time where we could get infected easily. And so learning various techniques how to manage the high volumes that we're seeing is. helpful as well. Well, we wish you and your staff all the safety you can have and all the contributions you can get. And we'll be checking in with you later on. How about that? See how things are going. Excellent. Thank you for having me on. And one last thing I wanted to mention, we are crowdsourcing face shields from

local 3D printers. So I think there are some innovations out there that the public can help us with. Those do have to be approved by our COVID command center. But being able to crowdsource face shields that we can use in health care from our local 3D printers is very innovative and is going to help us as we conserve and reuse our PPE. Thank you for joining us, Dr. Porrier. Thank you. Rob Porrier is Clinical Chief of Emergency Medicine at Barnes Jewish Hospital and the Washington University School of Medicine in St. Louis. Some hospitals like Barnes Jewish are turning to homemade cloth masks to fill their PPE shortages. Cloth masks are usually only advised as a last resort for health care workers,

but an increasing number of hospitals are seeking them out. A homegrown effort called the Million Masks Challenge has sprung up amidst this crisis. Volunteers are pulling out their sewing machines and extra fabric to make masks that are, are sent to health care providers, a website has launched to connect crafters and hospitals across the country that are asking for homemade face masks. Here with us now to talk about it is Jessica Choi, founder of get ppe.org. Welcome, Jessica. Hi, thank you for having me. Now, your organization helps hospitals find PPE they need. There are a lot of hospitals on your website asking for PPE right now, correct? That's right. We actually,

have close to 500 hospitals that are going to be on our website, and they have requested for PPE as well as handmade items such as masks. Wow. So volunteers make this stuff? Actually, we have a very large pool of volunteers. So we have about 25,000 volunteers right now across the U.S. And so they are helping, they're coming together and we're mobilizing them to help all these hospitals and facilities in need right now. And you find there's a big need? There is. We've seen that a lot of hospitals, when they initially came to our site, they were requesting for traditional PPE. But over time, even in the last week or so, we've started to see more and more hospitals open up to the idea of accepting these homemade masks. And a lot of health systems

have also publicly announced that they are calling on volunteers to come and support them. And what does the CDC say about these cloth masks? Do they think it's a good idea? The CDC actually said that in cases in which traditional PPE is not available, that health care providers can actually use homemade masks. And in times, they've also recommended that these professionals can use bandanas or even scarves. And this is a re-evaluation of their former stance. That's right. Say I have a sewing machine, right, and I have some extra cloth. I want to make a mask or a bunch of them.

how do I get the pattern to make one and then use get ppe.org to make sure that they get into the right places? That's right. So on our site, we have all the information you'll need, information about patterns that are accepted at different hospitals. And please note that a lot of different hospitals are requesting specific patterns. So it's not that there's one pattern that's universally used by all the hospitals. So we've seen about a good number of five, six different patterns that are floating out there that hospitals are specifically requesting for. our website details all that information. It also has general FAQs, tips and tricks, as well as all the locations that are accepting these handmade masks. We also will have this feature to match volunteers to different hospitals in need. And so you'll be able to choose whether you want to be

matched to a hospital in your local region or a hospital in a hardest hit area. Are these like sewing circles in the old days? People get together in a circle and start sewing, but they're doing it in different places? Yes, we've seen these groups come up all over the U.S. and we have groups that are smaller, but we also have big groups like citywide. All together, we have about 25,000 volunteers that are part of our network right now.

Are there certain fabrics that we should be looking out for to use? So our group generally advises to use 100% cotton, and that's to ensure that the fabric is able to allow for it to have good breathing. Do the hospitals generally know that your organization exists? Yes. So we have different organizations that we've reached out to and are working. We also have different cities that have reached out.

And we are actively working on how we can partner to spread the message, to bring more volunteers as well as to have a comprehensive database of all these different facilities and hospitals that are in need. So tell us if I'm a hospital and I'm listening, how do I get your help? So please visit our site, get p.pe.org. And on there, you can fill in a request form. You can also email us. And then we, on a regular basis, are adding to our list of facilities that are accepting PPE.

We are also making sure, once you fill out that form, we will contact you back to make sure that these are verified requests. And from then, we will redirect a lot of our volunteers to these different facilities. This is Science Friday from WNYC Studios. I understand that get pPE.org is a partner in the Million Mask Challenge. Tell me about that. What is that? The Million Mask Challenge is a global soathon. And our goal is to hit 1 million masks across all different countries.

And right now we're assembling lots of volunteers to join us in that effort. Is there a way to keep track of when you get to? half million, three-quarter million, a million? Yes. So on our sites, we have this tallying system where different groups can come and tell us the progress that they have made. And this will help us keep track of which hospitals still need more supply, as well as highlight areas where we need more volunteers to focus on.

And what kind of responses have you gotten so far from the health care workers? We've gotten very positive response from them. I was just on a call today where I had told this lady that we have fabric masks for her. And she started crying because she had reached out telling us how in desperate need they were for any supply. And now that I was able to contact her, she was so grateful. And I think that's the story that we're hearing across the nation, across different countries, where all these volunteers are coming together and helping the local community, even areas, that they're not part of.

Wow, what a story. And this is a lot of coordination for a small group of volunteers. Do you think this is something that the federal government should be handling on a larger scale? Shouldn't the federal government be giving you a hand in something like this? One of the things that we'd really like for the federal government to help on is if they were to look out of these different patterns that are floating around, If they were to give us more guidance on which one we should all focus on, we'd be a lot more efficient. But what we see now is we have all these different facilities. We have about 500 facilities right now.

Each of them are giving us a different pattern that volunteers are supposed to. And that causes a lot of confusion, but also it slows down the process, right? Because we have a lot of volunteers who are willing to help, but just sorting out all these instructions become a bit of an issue. That's it. The preparation time could just kill your will. Yeah. And so what we're trying to do on the site, though, is provide a lot of guidance on that standpoint because we're able to highlight all the different patterns that are needed and specific instructions. We also have all these Facebook groups at the national level, as well as regional levels that are able to give more guidance to volunteers who are willing to sew and help out. Now, I know that getPPE.org also shares information about blood drives happening across the U.S. How does blood fit into the coronavirus crisis?

So what we're seeing is that because a lot of people are staying at home, they're not able to go and donate blood or they're not visiting different blood drives that originally were set up. And so what we know is that we've had thousands of blood drives that have been canceled. There is a big shortage of blood right now. And so what listeners can do, they can actually go schedule to do a blood donation. And so we have more information on our site as well for that. So you can feel safe. You will be done absolutely as safe as you can make it. That's right.

And a lot of these facilities are aware of the concerns that, that people may have, and so they're doing their part to keep everyone safe. You know, that's one of the unintended consequences. Who would have thought, now that I think about it, yeah, there's going to be a blood shortage because people are there in their homes. They're not leaving. Yeah. Well, good for you.

Thank you very much for taking time for us. Give us one more time, the website that we can all visit. It's get p.pe.org. And please come and join our effort to helping all the community, health providers out there. I hope we've done our little part for you, Jessica. Thank you for doing what you do and taking time to tell everybody else about it. Thank you so much. Jessica Choi is the founder of getppe dot org. And if you want a tutorial on how to make a mask, you can go to million mask challenge.com slash information and also get ppe.org will help you out with all of your patterned questions.

This is Science Friday. I'm Iroflato. About 1,800 meters down off the western coast of Costa Rica. There's a feature called a methane seep on the seafloor. It's a place where methane and other hydrocarbons slowly escape from within the Earth's crust. And like the more well-known hydrothermal vents, methane seeps are home to an unusual array of wildlife. Writing this week in the journal Science Advances, researchers describe two species of tubeworms that live in a symbiotic relationship with bacteria, and that relationship allows them to rely on methane for their nutrition.

Sci-Fright director Charles Burkwrest spoke with Shana Gofredi, an associate professor of biology at Occidental College in Los Angeles, one of the authors of the report. Thank you for joining me today. Thank you, Charles. Set the scene for us. What do these worms look like? When you descend in the submersible, you know, it's pitch dark and you land on the seafloor.

And when you flip on the lights, you see that there are these amazing, almost thicket-like congregations of these worms. And they make these really beautiful white calcium carbonate tubes. And so they're quite obvious. And you also see a lot of other animals that live only in these habitats all kind of piled on top of each other. It's actually quite a stunning scene on the seafloor. So there's this mineral-looking tube with the worm inside it, and then at the top is a fern-fron-like structure that's the top of the worm? Yes, right. So these are all tube-dwelling worms, and so they either make a tube out of minerals or they can make a tube out of mud.

And in all cases, they stick out this really frilly, beautiful head that they use for, primarily for respiration or breathing, but also in the same. in some cases, feeding. And then in the case of the worms that we reported on, they're actually using them as a surface to grow bacterial symbionts. And that's special to these worms in particular, or do other worms do this too? Well, there are many examples of worms that have formed beneficial partnerships with bacteria that are unrelated to these worms. And sometimes they keep them on the outside of their body and sometimes they provide a special organ or tissue inside their body to host them. But this is the first time that we've seen this kind of worm that hosts methane-oxidizing bacteria on the outside of their heads, essentially.

Is it as simple as bacteria eats the methane, worm eats the bacteria, or is it a more complicated relationship? Yeah, I'd say that in simplicity, that's a reasonable statement to make. However, there is a lot of negotiation that goes on with these relationships. So you can think of them as beneficial reciprocity or beneficial exploitation, you know, mutual exploitation, however you want to see it. But there's a lot of complicated communication that goes on between the partners. So this worm does not have any other bacteria on its body besides this special bacteria. And so there is, there must be some kind of what we would call a molecular handshake

that they can recognize each other from all the other possible partners down. there. And so I suspect that the relationship is much more complicated and that there's a lot of subtle things going on in the background that we don't yet have a good idea about. Would it be accurate to say that there's somehow farming the bacteria, or is that not the right term to use in this relationship? No, I think that's a farming is actually a great term to use. And whenever an animal teams up with bacterial partners, they do one of two things in order to get nutrients from them. They can either milk them. so just sort of slowly encourage them to leak nutrients to them.

But in this case, they're probably farming, and many animals do do that. And we might even do that in our own digestive systems. We digest a lot of bacteria that are in our digestive system for nutrients, and these animals are doing the same thing, these worms in the deep sea. Are they actually eating the bacteria in the way that we would think of with a mouth and a gut, or is there some other process going on here? Well, we do see that these worms have a digestive system, but it is not. filled with these bacteria, and we suspect, based on microscopy, that these animals are actually

digesting them, or engulfing them, you can think of it as a better term, across their skin, essentially. And it's the skin or the epidermis of their crowns, which are their heads. And so we can see in microscopy that they're actually engulfing these cells and that those bacterial cells end up further down in the tissues, and we suspect that's how they're being incorporated. And we know that this happens rather quickly because in our shipboard experiments, within 24 hours, we could trace carbon that comes from methane molecules that we offered to them into their bodies. And so within 24 hours, there's a substantial signature of methane in their tissues. How do you tell that it's your methane that's going in? How are you tracing its process? That's a very good question. So we actually

label the methane with a special isotope. So most carbon exists. in the carbon 12 form, and we gave them carbon 13 methane, so we can track the amount of carbon 13 into the animal tissues. Are they getting all their nutrition from the bacteria and the methane, or are they consuming other things, too? Yeah, so we currently believe that this is what's called a facultative relationship, so the worms benefit from it, but they, they're not completely dependent on it. And there are many examples of animal microbes and bioses that are facultative, but there are many that are obligate, meaning that the animal must have their bacterial symbionts to survive. So we think in this case that the animals, the worms do retain an ability to feed.

We don't think that that happens very often in the cold seep environment because they've got plenty of methane around to fuel their symbionts. But for example, we transplanted some of these worms about a kilometer away from the active seeping area, and they survived for 16 months without methane, and we suspect that in that case they were feeding on their own, and their tissue suggested that. So we do think that they retain some ability to feed on their own. I feel like people might be familiar with the idea of hydrothermal vents, but maybe less so about these cold methane seeps. Can you describe them for us? What's going on there? Most continental margins around the world have these habitats close by, and those are called

methane seeps. And we think of them as a kind of a cold water analogy of hydrothermal vents in that there's a lot of reduced chemicals like methane and hydrogen sulfide that are fueling the communities, whether they're microbial or animal communities. And they exist along the continental margins because there's a lot of primary productivity that occurs there. And that organic matter gets buried and it gets converted into to these reduced chemicals. So methane and hydrogen sulfide results from the activity of other microbes that are living in the sediments. And then there's a geological phenomenon along the continental margins where there is subduction of the earth's plates under the continents, and that squeezes these chemicals out

from the seafloor or shaves off whole, you know, sea mounts and then reveals those chemicals as a possible source that's more at the surface. When we talk about methane down there, is there a large reservoir that potentially a petrochemical company would be interested in drilling for, or is it more of a gradual process sort of coming out of my compost pile or something? I think there are probably a number of ways to think about that.

So there is methane seeping out like might be on your compost pile. But also there are methane hydrates. So this is methane tied up in sort of an ice, like molecule, molecular structure. And that has been discussed as being mined. And there are some estimates that the methane hydrates on the planet equal all the fossil fuel reserves that still exist. And then, of course, there is oil and gas in these areas as well.

So they do coexist in the same habitat as these methane seeps and these very unique and diverse biological communities. Do you see actual bubbles of methane, or is it not in that quantity? It's a more dissolved in the water process. Oh, yeah, no, you see streams of methane bubbles. It is very forcefully coming out. It's not like a hydrothermal vent, like volcanism, but it's definitely streams of bubbles. And when we take samples of sediment by something we call push core, we often liberate a whole bunch of bubbles that will emerge.

and those are all filled with methane. And I should make a point to say that it is possible. So not much methane ends up in the water column. A lot of methane is being produced in the sediments by microbes, but there's also many more microbes that are consuming methane in the sediment. So very little of it reaches the water column and even less reaches the atmosphere. And we have some of these animals maybe to thank for that because they're hosting methane oxidizing or methane-eating bacteria

that are essentially consuming that methane before it has a chance to reach the atmosphere. And methane is quite a potent greenhouse gas. And so we consider them to be providing an ecosystem service for the rest of us, for sure. Where are these communities geographically? Are they in one specific place? Or can you find these all over the world? Well, methane seeps are found all over the world along continental margins. So, you know, along the West Coast of the Americas, but also on the East Coast.

all around, basically all continental margins. But if you are asking about these worms in particular, we discovered them off of Costa Rica, but we suspect that they are worldwide based on reports of the same genus of worms and other habitats, not just cold seeps, but also hydrothermal vents. And so we suspect this phenomenon of using methane-eating bacteria as a beneficial partner probably extends beyond the seeps in Costa Rica.

And how far down do they live? These were at 1,800 meters depth, so approximately a mile, but there are many other examples of them living deeper than that. To look at these, you obviously, I mean, they're a mile down. You weren't free diving to look at these. How did you study them? Yes, so we were lucky enough to be able to have a project funded by the National Science Foundation where we could use the human-occupied vehicle, the Alvin.

And we were out there on three different expeditions. with Alvin over the course of three years. And it's quite an exciting experience to be in a submersible. I liken it to being in the front seat of your car with three other people for nine hours. And when you get to the seafloor, it's pitch dark. And there's all kinds of amazing bioluminescence of the animals that are, you know, bouncing off the submersible reacting to the electricity that is given off by the submersible. And then you flip on the lights.

And like I said, it's like an incredible world down there that we hardly ever get to see. Is it completely alien or is there any environment or community on Earth that would be somehow analogous on the surface? I'd say it's completely alien. And the reason why I say that is not just the types of animals that are there, but the speed at which life exists. It's probably the most peaceful place I've ever been. in terms of just the, yeah, the pace seems just so slow and peaceful. You're listening to Science Friday from WNYC Studios. I'm Charles Berkwis talking with Dr. Shana Gofredi of Occidental College in Los Angeles

about her research into deep sea tube worms. So an undersea expedition with the Alvin and all of the support crew doesn't sound like a minor undertaking. No, certainly not. It's years in the making. There's usually a handful of scientists that are the lead principal investigators on a research proposal. Sometimes it's funded. Luckily, we were funded. And this was a collaboration by at least five different universities in the U.S. and then also some Costa Rican colleagues. And then on top of that, about 40 different scientists came on board the ship with us over many years, the three different expeditions,

and also had a role to play. And each of us has a different skill. And it's an amazing collaboration between many different people that have these different expertise. And that allows you to do interdisciplinary science where you can really see these problems or approach these problems from different perspectives, which then, of course, gives you the whole picture eventually.

So it was a really exciting international collaboration. among scientists. What is it that amazes you most about these worms? Is it just the methane relationship, or is there something deeper or larger? I'd say what amazes me the most is that these worms have been studied for a long time, or at least known to exist in these habitats, and we've overlooked them in terms of the possible novel nutritional strategy. And I think that's the case for a lot of animals in the deep sea, especially, as we can assume one thing about them, but they might surprise us and are doing something completely different. And so it's important to look closely and expect novel processes from them. I'm also fascinated by this idea. There has been on earth records of 200 million

year old fossil seeps that have large congregations of these surpulids. And this has been a mystery to scientists for a long time. And I think we finally solved the mystery of why we see all of these fossil tubes of serpulids when they weren't ever suspected to be tied to the seeping chemicals at all. And we have finally realized that they actually were relying on the methane that was coming out of these seeps. And they were there as a natural endemic member of those communities. So they've been around for over 200 million years and they're down there today. It's just that it's pretty hard to explore the deep sea and find these new ways of life that has been occurring all this time. So I think we often think about the world as in a sort of survival of the fittest or sort of

exploitive relationship. Is it possible that there are a lot more of these symbiotic relationships than we know about that they're just going on in the background behind us all the time? Yes, you actually hit on one of my favorite things to discuss with regard to symbiosis is that we are taught that life is competitive and it is survival of the fittest. And I would argue that there are many more cooperative relationships that get a lot further in life than there are competitive relationships. And I think for the longest time studying symbiosis between animals and bacteria was considered just sort of an exotic thing to study. Maybe wasn't that relevant for more disciplines. But now we realize even with the human body and the human microbiome, that actually

symbiosis is probably the norm. And to not have any bacterial symbionts would be quite rare. And so it took a lot of pioneers in the research field of symbiosis to show us that. What's the next thing that you want to learn? The next goal for the next big dive? Well, we are hot on the trail of another very interesting symbiosis that we discovered in the Gulf of California. And these are at the deepest known hydrothermal vents in the Pacific at 3,800 meters depth. and I may not tell you much more about that, but we are currently writing the manuscript. Well, good luck with that. And thank you for joining me today. Of course. Thank you, Charles.

That was SciFri Director Charles Berkwist speaking with Shana Goughradi, Associate Professor of Biology at Occidental College in Los Angeles. If you missed any part of this program or you would like to hear it again, subscribe to our podcasts or ask your smart speaker to play Science Frighton. Every day now is Science Friday. And on the SciFri Vox Pop app, we're looking for the sounds of spring in your neighborhood. Bird song, things growing, planting your garden, we want to hear it. That's on the Science Friday Vox Pop app wherever you get your apps.

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