Science Friday - Cat Purrs, AI Darth Vader Voice, Deathcaps, Eating Jellyfish. Oct 28, 2022, Part 2

Episode Date: October 28, 2022

Why Do Cats Purr? An Investigation Into A Purr-fect Mystery Science Friday recently received a voicemail from a listener named Violet from Maui, Hawai’i, who wanted to know: Why do cats purr? We wanted to see what other cat lovers knew about cat purring. So we sent our talented SciFri colleagues Diana Montano and Kyle Marian Viterbo to the Meow Parlor, a cat cafe in New York City to find out. Guest host Katherine Wu, who recently wrote about why cats purr for The Atlantic, also talks with Robert Eklund, professor of language, culture, and phonetics at Linköping University in Linköping, Sweden. He explains what we do and don’t know about how and why cats purr.   How To Digitally Recreate Darth Vader’s Voice From A War Zone James Earl Jones played Darth Vader for 45 years. But this September, he officially stepped down from the role. Fear not, Star Wars fans—the villain isn’t gone for good. Instead, the filmmakers have teamed up with the Ukrainian AI company Respeecher to recreate his voice. Respeecher can convert one person’s speech into the voice of another. The company’s work has appeared in the Star Wars canon already, as Young Luke Skywalker in “The Mandalorian” and “The Book of Boba Fett.” And just last month, they debuted their Darth Vader mimic in the T.V. show “Obi-Wan Kenobi.” They always knew that it would be challenging to recreate Vader’s iconic voice. But their job got a whole lot harder when Russian troops invaded their nation. Respeecher chief technology officer Dmytro Bielievtsov and sound engineer Bogdan Belyaev join guest host Kathleen Davis to talk about their work.   Toxic Death Cap Mushrooms Take Root In The Mountain West Toxic mushrooms are not unusual in the Mountain West. “This is probably a lepiota,” said Susan Stacy, looking at a mushroom on a recent afternoon in a Boise, Idaho, neighborhood not far from downtown. “See that little dark nub in the middle and little flecks around here?” Stacy turned to her mushroom identification book. “Edibility: to be avoided. Perhaps poisonous,” she said. While this little mushroom could be problematic for a curious dog or child, it doesn’t compare to one of the world’s deadliest mushrooms – which Stacy discovered in Boise last September. She remembers that it was a hot day, and she decided to take a detour from her normal route to check out a busier area where many lawns were “generously” watered. “And here I come upon this mushroom, and I knew it was an Amanita because I had seen them before. And an Amanita, to my mind, is a gorgeous, statuesque, elegant creation. They’re just stately,” she said. The genus Amanita includes, incidentally, the species on which the red and white mushroom emoji is likely based, which also happens to be poisonous. Read the rest of this story on sciencefriday.com   Will A Hotter World Make Jellyfish Haute Cuisine? The ocean is filled with delicious ingredients, but our favorite seafood items might not stick around on menus forever … thanks to climate change taking its toll on fisheries. As a result, scientists are thinking more and more about what the future of food is going to look like—what ingredients we should eat more, and what we should eat less. That could mean we’ll eat more items like kelp, oysters, and mussels, which are a great source of nutrients, since they can be sustainably harvested. But there’s another seafood that’s being encouraged as a food of the future. But it’s a little more unfamiliar—and maybe surprising—to most of the world. It’s jellyfish. Although it’s a fairly common ingredient in several countries, like China and Vietnam, it hasn’t quite broken into the international market yet. Guest host Katherine Wu talks with Agostino Petroni, a journalist based in Rome who reported on the topic for Hakai Magazine, and Dr. Antonella Leone, a researcher at the Italian National Research Council’s Institute of Sciences of Food Production, based in Lecce, Italy. They talk about the benefits of jellyfishing, what it’s going to take to catapult jellyfish into the international seafood market, and their favorite jellyfish recipes.   Transcripts for each segment will be available the week after the show airs on sciencefriday.com.   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 Catherine Wu, and I'm Kathleen Davis. A few months ago, we got a voicemail from a listener asking a very important scientific question. Why is the reason cats purr? I'm just very interested with that because my eight-month-old cat is like always purring. I wonder why they purr. Wow, what a great question. And today, we're going to try to get to the bottom of it. Last month, I actually looked into why cats per for a piece in the at least. Atlantic. I was inspired by my own two cats, Calvin and Hobbs. When I have bad insomnia, their purrs are pretty much one of the only things that can wool me to sleep. Wow, so soothing. Katie. Katie, Katie, wake up, wake up. Oh my gosh, Kathleen, I am so sorry. That just put me right to sleep. Oh, all right. I'm here. Kathleen, you're a cat person too, right? Have you thought about why your cat Miguel purrs? Yes, I have thought about why my cat purrs. He purrs when he's happy, but he also

purrs when he's hungry and when he thinks he's about to get food. So I have a lot of questions about what's actually going on in his little body when he purrs. But, I mean, listen to these good vibrations. So we wanted to see what other cat lovers knew about cat purring. We sent our talented sci-fri colleagues, Diana Montano, and Kyle Mary in Batarbo, to the meow parlor, a cat cafe in New York City to find out. I have heard the cats purr when they are happy. I also know that sometimes they do it when they're unhappy because it suits them. I know that they purr if they're like, should be satisfied or happy?

But then I also know there's a morbid one where like if they're about to die, they also purr. I mean, I have a friend whose cat, Haku is constantly purring. Like every second, sometimes if you're quiet at night, you'll hear him purring. As he's walking down the hall, he's so loud. I would say that the kittens purr a lot more. I notice a lot more purring from just like you touch them and they're like, oh, my God. And the adults are like, okay, what are you doing? Could not tell you scientifically why that is happening, though.

What an emotional roller coaster, too. There's happy theories. There's kind of not so happy theories. I feel like it's time to dig into the science. So joining me now to talk more about what we do and don't know about why and how cats purr is my guest. Robert Eklund is a professor of language, culture, and phonetics at Lynn Sherping University in Lin-Shirping, Sweden. Dr. Eklund, welcome to Science Friday. Thank you, so happy to be here.

Yeah, it's great to have you. So let's start with the basics of purring. What exactly is a purr? And how is it different from another cat vocalization like a meow? If you use a stringent definition, it should be a continuous alternating aggressive and aggressive sound produced by the lungs. And that means that the lungs push and draw air in and out of the lungs and through the voice poics. It sounds like purring is the ability to sort of vibrate one's vocal cords while both inhaling and exhaling. Yeah. And to be exact, inhale.

and exhaling using the lungs. So if you listen to purr or even try to mimic it, it would be like, where every second phase is done by exhalation and every second phase is down by inhalation. Not all cats purr, lions, tigers, leopards and jaguars definitely don't purr, but they can roar instead. And the opposite goes for the cats that purr. They can purr, but they can't roar. Not only cats per, it's been proven that Jenets per, pole cats, purr, and possibly even the Fossa, which is endemic to Madagascar.

How come some of them don't purr, like the four big ones I mentioned before, and the smaller ones all purr as far as we know? And already in 1833, the very famous zoologist or biologist Richard Owens, he noticed that if you dissect at voice boxes, you will find the difference. One of the sort of structures in the voice box is made out of cartilage in the bigger cats, the roaring cats. Whereas that same structure is ossified. It's made out of bone in the smaller cats that do purr.

And he made that the explanation, and another solomagist sort of draw the conclusion. So if you have a cartilage, you can stretch the voice box. And if you can stretch it, you can roar. And if it's solid as in bone, you can't stretch your voice box. And that results in the drum roll, as it were, that is called purring. The thing is that it's agreed right now that that can't be at least not the only explanation. There are other differences as well. And so when we're talking about the animals that can do the bona fide purr,

I understand that cheetahs are among them, among the big cats that are able to do this. And you've recorded this, right? So I did a small paper. I recorded the cheetah, the huge and very kind Cheetah. It's one of the biggest cats I've seen. And then I recorded my girlfriend's tiny little domestic cat and produced wrote a paper with Gustav Peters. What was funny is that although the little cat weighed around seven pounds and the cheetah weighed in at 180 pounds. the frequency, the sort of the tone where purring was produced, was about the same.

If you translated to a key on the piano, it would be basically the same keys, despite this huge difference in size. I want to get to the big central question here. Why do cats purr? Most of us who have been around a purring cat, I think, have this connection between purring and happiness. But that's not always the case, right? And that is actually one of the things that is established. Cats can purr also when they are in pain, when they give birth, when they are about to die, and then they are very nervous or uncomfortable. Cheetahs who are really prominent purrs, they purr like crazy, at least if they are tame. Why cheetahs?

We don't know because they're out in the wild. And I've asked people working with cheetahs, you know, I've bred cheetahs for decades, and they have never heard a cheetah purr for any other reason than being very happy and content. Wow. So why do domestic cats purr for different reasons, or at least in different context, vocalizing is some kind of signaling to the outworld what's going on. And either within your species or to another species. And purring in this case could be labeled as some kind of signal.

to the outer world that leave me alone. I want things to stay the way they are. And above all, I don't pose a threat to anyone. If you're happy content, if you're afraid, if you're dying, if you're giving birth, you definitely don't post a threat to your surrounding fellow cats or other animals. And so, you know, part of this cat human connection, I think a lot of people have in recent years been floating around this very interesting claim that cat purring might have special healing powers either for the cats that are doing the purring or other animals around them, maybe even us? Have you heard about this? And is there any evidence to back up this magic healing power? No, there is no scientific evidence for it. On the other hand, it is known that cats are beneficial to

your health, at least. Having a purring cat on your chest definitely does good things for your own health. The specific claim here, which was made around 20 years ago, was that purring help, healing fractures. It was a suggestion it had never been tested, neither by the author nor by anyone else. And the problem here is that it would be, well, the problem actually, happily, it would be very hard to be allowed to perform. form such an experiment because how would you do it? You would take two cats, preferably siblings, you will break their bones and then you would prevent one cat from purring and get the other cat to purr as hell and then check whether the fractures heal faster in the purring cat. And of course you can't do that. No ethical committee in the world would approve such an experiment.

And the idea as such is not stupid. It sort of makes sense. And NASA did some vibration studies because astronauts being in space for a long time, they lose both muscle tissue and also bone structure. So they tried vibration plates and stuff like that to see whether that would be a way of sort of preventing this to happen. and I never saw anything published, and it just faded away without anything being published, which I take some kind of evidence that they didn't get results they wanted. All right.

So, I mean, you've just given a pretty key example of why it is pretty tough to study, you know, purring in general, its effects. And also, I imagine, you know, the mechanics are really hard to test. Why is it so hard to study purring? I mean, cats do it all the time. Why can't we just see what's going on? Exactly when I did this recording of Kane and wrote my comparison between the domestic cat and cane, I was affiliated with the Karolinsky Institute in Stockholm doing fMRI analysis of human brains. And I spoke to the professor there, who is one of Sweden's most famous scientists.

And we discussed this and he said, yeah, let's put the cheetah in the MRI board. and see how he does it. And the thing is, you've already guessed it, is that it would be impossible to get a cat to purr in one of these really loud, scary machines. And that's the thing. If it were humans who purred, we would know how we do it.

Because you would take students offer them a cinema ticket or something like that, to put them in the bore and ask them to purr, and they would do it. With animals in general, I mean, cats in particular, you can't tell them what to do and when. Right. This is seemingly the eternal problem with cats. So interesting, but so hard to study. My cat certainly don't do anything on command. That's sort of the definition. Right. Well, there is clearly so much more to learn about cat purring, and I look forward to your work and others' work. I'll be following all of this closely. I think that is all the time we have, but thank you so much, Dr. Eklund, for joining us today.

It's a pleasure to talk about cats. Absolutely. I fully agree with that. Robert Ecclund is a professor of language, culture, and phonetics at Lynn Sherping University in Sweden. If you or your kids have a science question that's been nagging at you, we want to know. Share it with us on social media or go to ScienceFriday.com slash contact to get in touch. We'll try our best to answer it on the show. We have to take a quick break now, but when we come back, we'll be talking about Star Wars. This is Science Friday from WNYC Studios.

This is Science Friday. I'm Catherine Wu. And I'm Kathleen Davis. I don't know about you, but when I think of famous cinematic moments, one of the first that comes to mind is Darth Vader's signature line. I am your father. James Earl Jones voiced the Star Wars villain for 45 years until last month when he officially stepped down. If you're wondering who's replacing him, well, that's complicated.

It's not an actor, but an AI mimic, one that recreates James Earl Jones's voice from nearly 50 years ago. The Star Wars filmmakers teamed up with a Ukrainian AI company called Respeacher. Respeacher converts performances from one actor into the voice of another. Take a listen. Hey, this is James. I'm an actor and this is my real voice. In this video, I'll demonstrate a couple of new features of re-speechers speech-to-speak's voice-cloning engine. Obviously, I can speak with another person's voice, but notice that now the sound is 44.1 kilohertz.

The company's work has appeared in the Star Wars canon already, as Young Luke Skywalker in the Mandalorian and the Book of Boba Fett. And just last month, they debuted their recreation of Darth Vader in the TV show Obi-1 Kenobi. Check this out. What you made me. Pretty uncanny, right? The company's path to the big screen has not been easy. Sure, they knew it would be hard to make a perfect mimic of such a legendary actor, but what they didn't expect was to have to do so under air raids and gunfire

as Russian troops invaded their nation. Joining me to talk about all of this are my guests. Dmitro Bia Levitzov, Chief Technology Officer at Respe. based in Kiev, Ukraine, and Bogdan Belayev, sound engineer at Reespeacher, based in Levyu, Ukraine. Welcome both of you to Science Friday. Yeah, thanks for having me. Yeah, hello. Bogdan, let me start with you.

Are you a Star Wars fan? I'm a fan from my childhood. When I was a kid, I watched the second episode of Star Wars. I didn't start from the first one. After the premiere, I was into it, let's say. Yeah. I imagine it would be really exciting to learn that you would be working on the Star Wars shows then. Oh, yeah.

I won't believe it if I knew that, like, you know. So what materials do you need to recreate a voice? Basically, we need recordings of the source speaker. It's like the actor who is going to be converted into the target voice and the target recordings, which are recordings of the voice that are we going to convert to. And where do you actually get these target voice samples from? Yeah, that really depends on the situation. So there are projects where we could just take ideal recordings, like from ADR,

if we're working on a movie. But if we're working on a historical character or someone whose young voice we want to make instead of their current voice, well, in that case, we'll have to go back and look for old recordings. And for big movie projects, usually the client would have some internal, like, archival recordings that we would end up using. And how much tape is enough to build a good replica of a person? Yeah, it really depends on how good the data is.

If we have like great ADR recordings, then we would be totally fine with 20 to 30 minutes of recordings. But in practice, especially with these characters that we don't have a good homogeneous recordings of, like for those cases, we would have to use as much data as we can. And like an hour or two hours would be great in these cases because, you know, some data is corrupted. some data has some noises, but we could still kind of pick out a half an hour of good material out of it. Okay, so you're using this tape to build a model of a target voice, and you have the performance of an actor whose voice you want to change. What aspects of speech does this model retain from the original source performance,

and what might get changed during that conversion? We take content, we keep the content. and we keep the performance, like the intonations, the level of arousal, whether the voice is whispering or half whispering or the projection. So we take all that from the source and then we replace their vocal apparatus in a way and we change the timbre. Also, we change slight phonetic kind of habits. So when someone tends to have like a very peculiar S or F, the network would, uh, replace that. So you don't need to actually try to mimic that as an actor. So it sounds like you still need at the core of this performance a great performance.

You still need that source actor to put on a show, right? Oh yeah, for sure. So you just need to, you know, use the linguistics and use the intonations and the style of acting, but you don't need to try to imitate any physical aspects of how that person sounds. Interesting. So as we heard a little bit earlier, your product really does sound like a real voice. I think if I were watching that Star Wars show, I might not even realize that it is a clone voice. Can you, as the creators of this technology, tell the difference between a real voice and your conversions? Yes, but I was hoping that Bogdan would say yes immediately, but... I was hoping that you would have been saying.

Okay, so yeah, I just wanted to say that our ears are having like the lower threshold of like detecting the conversions. But I had a few times when I miss the files and listened to our conversions as the real recordings and didn't notice the difference. So yeah, it's sometimes tricky. Yeah, I mean, it does sound a little bit scary. And in the news, I would say here in the U.S., we hear a lot about AI deep fakes that are used in scams or political propaganda. How does Respeecher make sure that this technology doesn't get abused for those more nefarious purposes? Right. Yes, there are two components of this. One is that we never give anyone the actual code so that they can run the technology.

So we keep everything in-house and we always make sure to obtain a permission from the actor whose boys were cloning. Interesting. So let's talk a little bit about the timeline for this Darth Vader project. So if I have done my math right and I have my dates correct, your team was working on this Obi-Wan Kenobi TV show right around the time that Ukraine was invaded by Russia. What sort of precautions and accommodations did you have to make to keep everybody safe? Right. Yeah. So probably like one of the most important parts of it happened exactly when the invasion happened. So what we did as a company is a couple of weeks before the invasion, we pretty much decided to kind of distribute the team a little bit. So we relocated part of the team to a different city to Lviv and.

But Dan also went to Lviv to work from there just in case, you know, something bad happens, which unfortunately did happen. Did either of you personally have to relocate? Yes, I had to, I think I stayed in Kiev for some time after this happened. But then I went to my parents' place for a couple of weeks, I think for four weeks or something. And then I came back. Yeah, I had to relocate. live because currently I cannot come back to my hometown because of occupations. Yeah, and Bogdan, I heard that your hometown was actually invaded. Do you remember what was going

on what you were doing when you heard that news? I mean, what was that day like for you? Yeah, I remember that I woke up at around like four or five o'clock because I heard that my wife was talking with our family members and I heard that her voice is shaken and I just directly understood that it happened. We were shocked as everyone for the first half of the day, but yeah, we were prepared. I think that in a situation like this, a lot of people would not be thinking about work, but did you keep working during this time on this project? Yeah. Yeah, it's surprise a lot of people. But yeah, every time when I think about these days, the first weeks of full-scale invasion, I still have more yes, that no, not to do that. Yeah. I mean, for me, I would almost feel like it's the one thing that I would be able to control, right, is like what I'm doing with my work. Is that something that maybe you were thinking about?

Yeah, exactly. Yeah. The thing that came in. to my mind that like our army is working at this moment and like we have electricity and we have internet connection and you could you can even go outside and get some bread or water or whatever so everything is working and for me it was like you know light when everything is dark around well all of your hard work on this project really paid off last month when this Darth Vader voice actually aired on the Obi-1 Konobi TV show. I mean, Bogdan, as the resident Star Wars fan, how did it feel to watch these voices air?

It's a big mixture of feelings, like, with happiness and, you know, some kind of fear and excitement and all of this stuff. My wife said, like, do you understand that it's like forever? And like, oh, come on, yeah. It's like, you know, it's saved and captured. and yeah, it will be somewhere like in 20, 30, 100 years. So now that you have seen that your product works, are you getting interest from other Hollywood productions?

Yeah, definitely. It's kind of a confirmation or sanity check for other companies that we're not messing around and we're making a technology that's worth their attention. Dmitrio Bogdan, thank you so much for sharing your stories with us today. Thanks a lot for having us here as well. Thank you. Dmitro Bia Levitzov, Chief Technology Officer at Respeacher, based in Kiev, Ukraine,

and Bogdan Believ, sound engineer at Respeacher based in Lvivu, Ukraine. And now it's time to check in on the state of science. This is KERNO, St. Louis Public Radio News. Iowa Public Radio News. Local science stories of national significance. The next few days are the peak of spooky season, and we couldn't ask for a better pallet cleanser than the death cap. It's an invasive mushroom that's been spreading across the world and has recently been found in the Mountain West. With me here to discuss the death cap is Madeline Beck, a reporter with the Mountain West News Bureau.

She's based in Boise. Madeline, welcome to Science Friday. Great to be here. To start us off, what exactly is a death cap mushroom? That sounds very scary. Yeah, it definitely does. But when you look at it, it doesn't look scary. I mean, some of the mycological folks and people that are really into funguses will be like,

oh, that looks like a very stately mushroom. Or they have these lovely descriptions, but really, like, for the layman, it looks like a mushroom. It's got, you know, it's a couple inches tall. It's got a little cap. It's got gills. The cap is a little greenish, yellowish with a little bit of a metallic sheen to it. It's got a thick stock. I mean, it looks like your standard issue mushroom.

But for those in the know, obviously, this is the potentially deadliest mushroom for humans in the world. It's largely credited with killing more people than any other mushroom. Gotcha. And so where are these death caps usually found? And is that starting to change? They've been found a little bit on the East Coast, but they really make the rounds on the West Coast. So they'd been initially identified there in the 30s or 40s in California. and now we just, this last year, found the first death cap in the mountain west.

And so that was here in Boise, Idaho. And now this year, the mushrooms are back again. That doesn't sound so great. And it sounds like just by appearances alone, it's pretty hard to tell whether you're looking at a death cap or something pretty harmless. Yeah, so it was originally identified by a woman named Susan Stacey here in Boise. she was part of a group called the Southern Idaho Micological Association. She found it, you know, just on a walk. And she realized, you know, what it was, brought it back to her group and said like, oh, this is cool. Like I found it in my book. It's, you know, an amina Faloides or a death cap. And people there were saying like, no, it's not. That's a lot. Like, that's not real. And they went over and looked at it and they're like, oh, Susan, you found a death cap. But like, what is going on here? But as far as how they were for sure certain, an actual former pathologist is part of the group.

His name was Mickey Meyer. And he helped confirm it using DNA analysis. We got between 99.85% and 100% match on the DNA sequence. And so by anybody's criteria, it would be a good, solid match. All right. Well, you have me convinced. And what is the leading idea on how these mushrooms managed to migrate into the region? These kinds of mushrooms tend to have a symbiotic relationship with specific kinds of tree roots.

And so in Boise, as in other places like Salt Lake and Denver, they imported trees from California decades ago as little saplings. But this specific kind of mushroom doesn't fruit, does not produce actual mushrooms above ground until trees are fully mature. So for these kinds of trees, it can take 30, 40, 50 years for that to happen, for them to actually reach maturity. So now all of a sudden, under these big old oak trees that were imported from California decades ago, that's where they're finding these mushrooms here now. The question is, you know, will they spread to other native tree species? We really don't know how they're going to behave in this area. So what I'm hearing is that this is our parents and our grandparents' fault.

Exactly. I mean, always blame them. Always. No, but in all seriousness, what are people supposed to do now that these mushrooms are starting to pop up in the area? How do people avoid them? Can anything be done to get rid of them? Yeah, so I wanted to be very clear just to start with that when it comes to, you know, this has popped up all around like Vancouver, British Columbia. and there they tried pretty much everything to get rid of it, including like fungicide, and really nothing they've done has helped. That just adds more poisons to their environment and kills healthy, nice fungus. So what we've really been talking with all the people in mycological associations have said is

you need to just know that it's here and know how to identify it. And with death caps, you can touch them. That's not going to hurt you. The concern is obviously ingestion for people or even pets like dogs. So, yeah, you can just pluck the mushrooms, throw it away. Not a problem. But if it is an actual death cap and it comes back year after year, you're probably going to have to do that year after year. Madeline Beck is a reporter with the Mountain West News Bureau. She's based in Boise. Thank you for being with me today. Great to be here.

We have to take a break. And when we come back, we're talking about seafood, specifically one ingredient that some people say the world should be eating more of. jellyfish. We'll be right back after this short break. This is Science Friday. I'm Kathleen Davis. And I'm Catherine Wu. Okay, Kathleen, for the rest of the hour, we're taking a deep dive into seafood. Well, that is excellent news because I love seafood. If we are ever at a party together, Katie, you can find me by the cocktail shrimp platter. Not if I get there first. And it's true. The ocean is filled with delicious ingredients. But sadly, some of our favorite seafood might not be around forever, thanks to climate change taking its toll on fisheries and all kinds of wild marine life.

So scientists are thinking about what the future of food is going to look like, what ingredients we should be eating more or less of. And we've talked about this on the show before here at Science Friday. For the ocean, that could mean eating more items like kelp or oysters or mussels, which are all a good source of nutrients and they can be sustainably harvested. And there's another seafood that's being encouraged as a sustainable food of the future. It's just a little more unfamiliar and maybe surprising to most of the world. It's jellyfish. I have to say I have never eaten jellyfish before, and it's never really crossed my mind as something that I could be eating. I'll admit I have heard of this being a thing because my parents have definitely eaten jellyfish.

They're from Taiwan, but I have not partaken myself. Jellyfish is actually pretty common in several countries. countries in Asia, like China and Vietnam, but it hasn't quite broken into most of the Western world. Researchers in Italy are trying to change that. Here to tell us more about jellyfish cuisine are my guests. Agostino Patroni, a journalist based in Rome, he recently reported on this topic for Hackeye magazine. And Dr. Antonella Leone, a researcher at the Italian National Research Council's Institute of Sciences of Food Production, based in Leche, Italy. and Antonella, welcome to Science Friday.

Hello. Hello, good morning. Wonderful to have you both. So can you tell us what exactly is the argument for jellyfish becoming a food of the future? More or less 10 years ago, we started to study jellyfish as a new resource for different uses. And we find that several species could be useful as as food. This was strange in our countries, but you know that jellyfish is largely used as food in

Asian countries. And there is an increase of population of jellyfish. Most could be suitable as a source of food or food ingredients. Got it. So it sounds

like this would kind of kill two birds or maybe two jellies with one stone. Jellyfish are taking over and we could eat them as a sustainable resource for ourselves. Antonella, you had mentioned that there is already a little bit of jellyfish cuisine going on in certain Asian countries. Agostino, how much jellyfish does the world consume as a whole right now? And is that expected to increase? At the moment, there is an estimate.

of 19 countries that harvest about 1 million tons of jellyfish every year. For a global industry worth about $160 million. Some say that this will grow, but it is not as easy as that, because, for example, in the European Union, in the Mediterranean, right now, jellyfish cannot be consumed and sold legally because they're not labeled as safe food yet. On this part of the world, especially in the Mediterranean and the European Union, we don't know yet what the market could be,

but as Antonella was explaining me, there is already some interest from some entrepreneurs that would like to take this on, right? Antonela? Yes, yes, there is a lot of interest. Fishermen and local industry, food industries are interested in exploit jellyfish, also because they represent for fishermen mainly an issue. They often are in the neck of fishermen and they cannot be used, cannot be told as a food. Many fishermen call us asking to be able to use this biomass, but also

chef and restaurants owners are interested in. The problem is, as Agostino rightly said, jellyfish are considered novel food in Europe. They cannot be consumed and fished for food until the European Food Safety Authority will authorise the consume of this biomass. Got it. So just one piece of this bigger puzzle. All right, Antonella, let's dive into some of the minutiae of actually cooking and eating jellyfish. So I understand that your lab is currently trying to learn how to do this in some optimal ways. What are some challenges that you've run into so far? And what have you learned? Regarding the type of jellyfish, the species of jellyfish that could be meat, and the studies about this.

Our role as a researcher is to study as much as possible the characteristics, the safety and quality characteristics of different jellyfish and provide scientific evidence that several species can be consumed, provide also information about the processing for food production, or processing for extraction of biotic compounds or to enhance characteristics of these products. That is our role as a researcher. After that, when we identified one or two species useful for food, we can contact chef and ask to improve or to check the feasibility of new recipes,

for example by using jellyfish as a main ingredient. And that was done with several chefs and publish a fun cookbook. It is really important to study the biology and ecology of all jellyfish, including species that are not human interest. Because we need to know as much as possible about the biodiversity present, in our seas. After that, we can study in particular for different topics. After that, we can transfer our knowledge to the stakeholder or public as we are doing now to communicate our results. Got it. But there is plenty of science to be had when you're studying how to cook a jellyfish,

how to preserve a jellyfish, even just how to prep a jellyfish. for something that's ultimately destined for a human stomach. Antonella, can you tell me a little bit more about how you can cook something that is 95% water like a jellyfish? And how do you preserve that for shipment and prep for cooking? There is different processing. The traditional system from Asia use alum, which is a mixture of salts of aluminum, to preserve jelly, to eliminate the water. This process is not so safe because aluminum can remain in the final products

and can have a bad effect on human health. So we patented a new process that use calcium salts. This is more safe and produce a new product, very different from the product from ASEAN. This helps also the chef to prepare a jellyfish from fresh jellyfish. I'm Catherine Wu and this is Science Friday from WNYC Studios. If you're joining us now, we're talking about jellyfish and if we should be eating more of them. What does it like to handle a jellyfish to prepare it? What does it feel like before you prepare it?

What does it feel like after? And I'm even wondering, is it the texture of celery, an apple, chicken? What is this like? So with Antonella, we went together to one of the restaurants that work with her to try new recipes in Leche. You know, Antonella went to the freezer of her lab and took two jellyfish. They were frozen because we didn't have time and it was not planned to go out at sea to fish them. And with a letter accompanying the box, who went to the restaurant and met the chef. And the letter was to allow the chef to cook it illegally as part of the research program.

The chef, first of all, lets the jellyfish defrost under the running water. And after about 20 minutes, he started handling them. You know, the first step that I saw was to put the jellyfish into boiling water, in order to cook them. And as I described that into the article, I received actually quite a few messages from readers on Twitter and other platforms asking, okay, yes, you're cooking it, but what about the venom, you know, that everybody's scared about? And so since we are here all together, I want to ask Antonella, what happens when you cook the jellyfish and what happens to the venom that stings people. How do we get rid of that?

Yes, we have to know what is the kind of venom of each species of jellyfish in order to consider what kind of process is able to eliminate or quench the venom. In the case of jellyfish that Agostino tried, it is Rizostomapulmo. Rizostomapulmo has a venom that we demonstrated was not stable. at high temperature. So the treatment with high temperatures is enough to eliminate the venom. But this is not the same for all species of jellyfish. Okay. Thank you. So which means people at home, please don't catch a jellyfish and cook at yourself boiling. No risk of that for me, I promise. Well, so Antonella, I understand you're the author of the European jellyfish cookbook.

Great bad name, by the way. Both of you, you know, tell me a little bit what it's like to eat jellyfish. You know, first, what does it look like on the plate? And what sorts of recipes does it end up in? Sweet, savory, salty? What is all that like? Jellyfish have a main characteristic, sensory characteristics. characteristics to be very salty.

We made also a study. Now it is published the study on the lexicon on the sensory analysis of jellyfish. We made the sensory analysis by professional panel. And the characteristic is to be very salty. And the other characteristic is the sea flower. but more similar to, for example, seafood like oysters. Yeah, I agree. It did taste like oyster.

You know, when we went to the restaurant, when the chef prepared the jellyfish in a kind of a tomato soup, I mean, it tasted just fine. It tasted great, and it tasted fishy, of course, if you are a fan of fish and chips, so you're looking for a fish which doesn't really taste like fish, then this might be a little bit of a problem when you try, you know, the jellyfish because it really tastes like the sea. But if you light instead, you know, kind of like stronger flavor, you might

appreciate jellyfish as well. And what was kind of interesting is that it is pretty crunchy, like a, I don't know, like a calamari. When you fry calamari and you, you know, bite into it. it's kind of like that or like a piece of fat from from a steak more or less yeah that's the that's the texture and but yes and of course one of the of the dishes that I tried was the fried jellyfish but of course you know as many of the people I interview that tried jelly fried jelly told me you know anything that is fried is good I can relate to that So I'm hearing about some crunchy, salty, fishy, oyster-ish food and it's delicious deep pride. I'm certainly curious.

Agostino, say we get a lot of people interested in this and say the jellyfish market really takes off. Could there be a downside to that? Could we end up overfishing jellies? Well, there are some cases where this actually happened. As I mentioned in the article, this actually happened in Mexico where fishermen turned to fishing jellyfish because there was high demand from Asia and all of a sudden they over-exploited the stocks of those jellyfish. Some collects consider jellyfish more sustainable of other fish or seafood because we catch only the adult's stage because jellyfish have two stages. One is the adult stage that is the belly fish and one is the polyp stage that remain on the bottom

of the sea and is able to produce more jellyfish. But this is not, it is not demonstrated that all the fishery is sustainable in all conditions. So we have to be very careful when we talk about sustainability because we need before to study the life cycle of each involved animal and the ecosystem in which the animal is and made studies along the years in order to consider how much we can fish of this particular species in order to maintain the species for the next generation.

Right. And certainly human practices that have led to overfishing for other species and human activities that have led to climate change are part of what got us into this situation in the first place. So we can't afford to make those same mistakes. Well, I think that is all we have tied for. I really hope I get to try jellyfish one day, but thank you both so much for joining me.

Thank you so much, Catherine. Thank you. Agostino Petroni is a journalist based in Rome. He recently reported on this topic for Hacke magazine. You can find a link to the story on our website. Dr. Antonella Leone is a researcher at the Italian National Research Council's Institute of Sciences of Food Production, based in Leche, Italy. If you missed any part of this program or would like to hear it again, subscribe to our podcasts, or ask your smart speaker to play Science Friday. You can say hi to us on social media, Facebook, Twitter, Instagram, or email us.

The address is SciFri at ScienceFriety.com. Send feedback and tell us what you'd like us to cover too. I'm Kathleen Davis. And I'm Catherine Wu. Have a great weekend.