Season 5: Episode 2

Unk Boop Kwa

Beneath the water lies a whole world of sound: snorts, boops, croaks, grunts. Fish, it turns out, have a lot to say, and they’ve been communicating for a long time. In this episode, we take a dive with some of the planet’s oldest vertebrates.

Guests

Extras

FishSounds.net is a great resource for exploring the world of fish. Here are the fish sounds we used in the episode:

Parsons, M. J. G., Salgado-Kent, C. P., Marley, S. A., Gavrilov, A. N., McCauley, R. D. 2016. Characterizing Diversity and Variation in Fish Choruses in Darwin Harbour. ICES Journal of Marine Science, 73(8): 2058-2074.

Picciulin, M., Calcagno, G., Sebastianutto, L., Bonacito, C., Codarin, A., Costantini, M., Ferrero, E. A. 2013. Diagnostics of Nocturnal Calls of Sciaena umbra (L., Fam. Sciaenidae) in a Nearshore Mediterranean Marine Reserve. Bioacoustics, 22(2): 109-120.

Pine, M. K., Wang, D., Porter, L., Wang, K. 2018. Investigating the Spatiotemporal Variation of Fish Choruses to Help Identify Important foraging Habitat for indo-Pacific Humpback Dolphins, Sousa chinensis. ICES Journal of Marine Science, 75(2): 510-518.

Parsons, M. J. G., Kent, C. P. S., Recalde-Salas, A., McCauley, R. D. 2017. Fish Choruses off Port Hedland, Western Australia. Bioacoustics, 26(2): 135-152.

Di Iorio, L., Raick, X., Parmentier, E., Boissery, P., Valentini-Poirier, C., Gervaise, C. 2018. ‘Posidonia Meadows Calling’: A Ubiquitous Fish Sound with Monitoring Potential. Remote Sensing in Ecology and Conservation, 4(3): 248-263.

Bolgan, M., Soulard, J., Di Iorio, L., Gervaise, C., Lejeune, P., Gobert, S., Parmentier, E. 2019. Sea Chordophones Make the Mysterious /Kwa/ Sound: Identification of the Emitter of the Dominant Fish Sound in Mediterranean Seagrass Meadows. Journal of Experimental Biology, 222(11).

Kaschner, K. 2012. The SOUNDS table in FishBase. FishBase (R. Froese and D. Pauly). World Wide Web electronic publication, www.fishbase.org, version (08/2012).; Tiepelt, H. 2005. Fish Sounds, Unpublished Data. FishBase SOUNDS Table.

Anderson, K. A., Rountree, R., Juanes, F. 2004. The Distribution and Behavior of Soniferous Fishes in the Hudson River: Focusing on Striped Cusk-Eel, Ophidium marginatum. Final Reports of the Tilbot T. Polgar Fellowship Program (J. R. Waldman and W. C. Nieder, eds.). Hudson River Foundation.; Rountree, R. A., Juanes, F., Blue, J. E. 2002. Soniferous Fishes of Massachusetts. Listening to Fish: Proceedings of the International Workshop on the Applications of Passive Acoustics to Fisheries, 77-84.; Stolkin, R., Radhakrishnan, S., Sutin, A., Rountree, R. 2007. Passive Acoustic Detection of Modulated Underwater Sounds from Biological and Anthropogenic Sources. OCEANS 2007, 1-8.

Staaterman, E., Ogburn, M. B., Altieri, A. H., Brandl, S. J., Whippo, R., Seemann, J., Goodison, M., Duffy, J. E. 2017. Bioacoustic Measurements Complement Visual Biodiversity Surveys: Preliminary Evidence from Four Shallow Marine Habitats. Marine Ecology Progress Series, 575: 207-215.; Staaterman, E., Brandl, S. J., Hauer, M., Casey, J. M., Gallagher, A. J., Rice, A. N. 2018. Individual Voices in a Cluttered Soundscape: Acoustic Ecology of the Bocon Toadfish, Amphichthys cryptocentrus. Environmental Biology of Fishes, 101(6): 979-995.

Casaretto, L., Picciulin, M., Olsen, K., Hawkins, A. D. 2014. Locating Spawning Haddock (Melanogrammus aeglefinus, Linnaeus, 1758) at Sea by Means of Sound. Fisheries Research, 154: 127-134.

Amorim, M. C. P., Vasconcelos, R. O. 2008. Variability in the Mating Calls of the Lusitanian Toadfish Halobatrachus didactylus: Cues for Potential individual Recognition. Journal of Fish Biology, 73(6): 1267-1283.; Amorim, M. C. P., Simões, J. M., Fonseca, P. J. 2008. Acoustic Communication in the Lusitanian Toadfish, Halobatrachus didactylus: Evidence for an Unusual Large Vocal Repertoire. Journal of the Marine Biological Association of the United Kingdom, 88(5): 1069-1073.; Amorim, M. C. P., Simões, J. M., Mendonça, N., Bandarra, N. M., Almada, V. C., Fonseca, P. J. 2010. Lusitanian Toadfish Song Reflects Male Quality. Journal of Experimental Biology, 213(17): 2997-3004.

Fish, M. P., Mowbray, W. H. 1970. Sounds of Western North Atlantic Fishes, A Reference File of Biological Underwater Sounds. The Johns Hopkins Press, Baltimore, MD.; Kaschner, K. 2012. The SOUNDS table in FishBase. FishBase (R. Froese and D. Pauly). World Wide Web electronic publication, www.fishbase.org, version (08/2012).

Rountree, R. A., Juanes, F. 2017. Potential of Passive Acoustic Recording for Monitoring invasive Species: Freshwater Drum invasion of the Hudson River via the New York Canal System. Biological Invasions, 19(7): 2075-2088.

Rowell, T. J., Schärer, M. T., Appeldoorn, R. S. 2018. Description of a New Sound Produced by Nassau Grouper at Spawning Aggregation Sites. Gulf and Caribbean Research, 29(1): 22-26.

Credits

Transcript

[00:00] INTRODUCTION

AMY: The time is a few hundred million years ago. The place is the ocean. Any ocean. And you are a fish—one of the planet's first vertebrates.

You have emerged into a very quiet world. There's the snap and crackle of shrimp and other invertebrates, but usually, the loudest sound in the sea is the water itself, washing up against your fins and scales. But then one day, you feel it. An urge to be heard. To declare your presence. You squeeze the muscles around the little balloon inside your body, your swim bladder, and a call rings out into the darkness.

TOADFISH (Staaterman, “boop-grunt-swoop”)

 And to your surprise, somebody calls back.

UNKNOWN (Parsons, “unknown single call 1”)

Fish were among the first marine animals to use sound for communication. Of course this ability evolved gradually, not all at once like I was playing with here. But still, after more than four billion years of very quiet oceans, fish began to fill the sea with their voices. 

FISH SOUNDS

AMY: It was the dawn of a new era—the birth of dialogue. Conversations made of clicks and thumps, croaks and whoops, and….whatever you'd call this.

FISH RISING CALL

LAUREN: Ahh, this is my favorite one….

AMY: (laughter)

AMY: Welcome to Threshold, I'm Amy Martin, and this is marine biologist Lauren Hawkins. 

LAUREN: So just like many other animals in the ocean that we know of, like whales and dolphins, fish also produce sound to communicate.

AMY: This season, we're listening to our fellow Earthlings roughly in the order in which they evolved. Fish are way, way back in that timeline: after microbes, corals, and some other invertebrates, but long before almost everything else. And the earlier a creature emerged in that story, the wider the gap between them and us, at least in our own minds. But Lauren says listening to fish communicate—even just knowing that they can and do communicate—starts to open up a portal between our two worlds.

LAUREN: Yeah, listening to fish has definitely given me a very different view into how to value life other than human life.

AMY: Fish are an essential food source for everything from otters to osprey to the dolphins we met in our last episode. And for us humans, too. A world without fish would be a world in which food webs collapse, and billions of people go hungry.  So it is very much in our own interest to pay attention to what they have to say. But also, fish are our neighbors. They don’t look like us or act much like us, but that doesn’t mean they’re not worth getting to know. In fact, those differences are a big part of what makes fish conversation so fascinating—and useful. These animals have stories to tell about some of the parts of our planet that are the most mysterious to us. In this episode, we’re going to meet people who are figuring out how to listen to these fish tales, and learn from them. 

INTRO MUSIC

[04:08] SEGMENT A

AMY: It's early spring, and I'm standing on a frozen lake in northern Sweden. The ice is at least two feet thick, maybe three, but I know there's a little hole drilled through it here somewhere, hiding under a thin layer of crusty snow. I'm using my cross-country ski pole to find it.

SPLASHY SLUSHY SOUNDS

AMY: Ah, there it went.

AMY: This is an ice fishing hole, just big enough to drop a line down into. But I have a different purpose in mind.

AMY: I'm going to hook up a hydrophone, which is basically just a microphone at the end of a long, waterproof cord, and the microphone itself is waterproof. And I'm going to plunk it down there into this very cold lake and see if we can hear any fish, or any other signs of life.

AMY: What you're listening to here is the beginning of a passive acoustic monitoring session. That sounds kind of fancy, but it's not. The basic idea is you take a microphone, connect it to a recorder, and leave it running while you exit the scene.

AMY: Sigge's very curious about this. Don't eat my mittens.

AMY: My technical assistant for the day is a handsome fellow named Sigge with big brown eyes, a distinctive profile, and a strong desire to chew on my gear. As I lower the hydrophone down into the lake…

UNDERWATER GURGLE

AMY: …he decides to do some energetic digging up on the surface. And I can hear every scratch of his paw through the hydrophone. It's shocking how well the sound translates down into the water through this thick layer of ice. It makes me realize that every noise we make up here on the surface impacts the acoustic environment in the water below.

SIGGE: dig dig dig dig dig (hydrophone)

SIGGE: dig dig dig dig dig (regular mic)

AMY: You're being very helpful with this recording Sigge.

AMY: I cover up the recorder in case it starts to snow, clip into my cross-country skis, and head out across the lake. I want to get myself and my dog as far away from the microphone as I can, so none of our noise interferes with whatever might feel like coming in to visit. We'll check back later to see if anyone decided to talk.

AMY: Sigge, kom! (claps)

MUSIC

AMY: Fish live almost everywhere we find water—and that’s 70 percent of the surface of the Earth. We’re utterly dependent on these aquatic parts of our planet, but many of them are really hard to access, like the dark, frigid layer of water under a frozen lake, or the depths of the ocean. Lauren Hawkins says fish can serve as emissaries from those places.

LAUREN: We have to find ways to monitor the health of our marine environments. And fish are very good indicators for that.

AMY: I visited Lauren at Curtin University, in Perth, Australia, while she was working on her PhD in fish acoustics.

LAUREN: Acoustically we know very little. We hear all these sounds, and we're like, oh yeah, that, sort of, is most likely a fish because it's got these characteristics, but we don't 100% know. And we also don't know what fish they are.

AMY: People have known fish make sounds for a very long time. You can see it in the names we've given them: croakers, grunts, trumpeters. But even so, Lauren people are often confused when she tells them she studies fish acoustics—we don't really think about fish making sound. In fact many people, myself included, don't think about fish that much at all. Lauren says we don't even know precisely how many fish species exist on Earth.

LAUREN: Yeah, so much of the ocean is still unexplored. We're still finding new species of fish.

AMY: That surprised me. I mean, I'm as interested in finding extraterrestrial life as the next person, but...we don't even know all the life forms we have on this planet. So one of the many uses of passive acoustic monitoring is just answering the basic question of what animals live on Earth. And once who’s talking, we can start to ask about what they’re saying, and how they’re saying it, and why. Lauren says there are two main ways that fish produce sound.

LAUREN: So the first is through sort of strumming or stridulation of bony body parts. So that's like, you know, they flick their fin rays against their petrol girdle and things like that.

ZANDER: scrape

AMY: That's a freshwater fish known as a zander, or a pikeperch, doing this kind of percussive sound-making.

ZANDER: scrape

LAUREN: But the second is using their swim bladder.

LUSITANIAN TOADFISH: boatwhistle

LAUREN: And they use that as sort of like a resonator so there's like sonic muscles that, you know, contract the swim bladder.

LUSITANIAN TOADFISH: boatwhistle

LAUREN:  And it produces a range of different noises.

AMY: That is a Lusitanian toadfish, making a sound that scientists call a boatwhistle. Which is not the first thing that came to mind when I heard it.

LUSITANIAN TOADFISH: boatwhistle

AMY: Swim bladders are internal sacs that help fish swim, or at least float. They're filled with air, and most living fish species have them. By letting air in and out of the bladders, fish can move up and down in the water. People have swim bladders too...sort of. We call them lungs, and when we're in the water, we can also use them to help control our buoyancy. We are actually descendants of a branch of very  early fish that never developed swim bladders. Instead, they held onto their proto-lungs, and some of them evolved into the creatures that eventually crawled up out of the sea and became the first vertebrates on land. But that part of the story comes way later. For millions of years, fish were the most complex lifeforms on the planet—and likely the noisiest.

LOTS O'FISH

AMY: When scientists record these sounds, they give them fun names, like sneaks, unks, snorts, and boops. This is one of my favorites—an unknown fish creating its own little dance rhythm, using a sound that someone called a kwa.

UNKNOWN: kwa

AMY: The total number of fish species identified so far is around thirty-five thousand. Only about twelve hundred of those have been studied to see if they produce sounds—but of those, more than eighty percent do. That means there are tons of species of fish out there whose voices we either haven't heard yet, or we can't yet identify.

LAUREN: And even this morning, for example, I'm looking at a new dataset and I was like, what is that sound? I've never seen that sound before. And I was like calling everyone in, and I'm like, whale people! Is this a whale sound? Like, is this a fish? Is this a whale? We don't know. So it's a privilege to be able to eavesdrop and actually be like, wow, what's happening here.

AMY: If an alien civilization wanted to study human communication, they could scoop us up into their spaceships, and see how we react to different stimuli. Or, they could drop microphones down into our various habitats—without being detected presumably—and just listen to us being human. On our farms, in our villages, in big, bustling cities. Scientists interested in fish sounds face a similar choice. They can pull the animals out of the water and do things to them—often unpleasant things—to trigger responses. But Lauren says she was drawn to passive acoustic monitoring because it opened up a different way of getting to know these creatures.

LAUREN: I wanted to be able to look at the natural world in a way where I didn't have to interfere with the animals. I didn't have to get in the water with them. I didn't have to take things out of the water and mess with them and things like that.

AMY: Taking this more receptive role means we get to hear the sounds fish make when they're out there in the world, being fish, which is very different from anything that can be produced in a lab.

LAUREN: Acoustics is a really amazing way of sort of seeing into their private lives that you usually wouldn't know anything about and give you clues as to, you know, how they're going about their daily lives, and what things are associated with that.

AMY: Lauren says all kinds of surprising things crop up.

LAUREN: This is the sound that I found this morning and was like...what is this?    

AMY: She pulls the sound file up on her computer so we can listen to it.

AMY: Where was this recorded?

LAUREN: This was recorded in South Australia. Yeah.

AMY: And you just got this data.

LAUREN: Well, I've had it for a while, but I've just processed it. But this is the first time I've looked at it.

AMY: Lauren gives me her headphones, and hits play. At first I don't hear anything but underwater hiss.

LAUREN: (listening) So it's very low frequency, it'll be like mmmmm…

AMY: But then, out of that noise, a signal emerges.

MYSTERY SOUND

AMY: Oh, do it again.

MYSTERY SOUND

AMY: That's so cool!

LAUREN: Yeah, I know, right? But I have no idea what it is.

AMY: It's a monster!

LAUREN: It is.

 AMY: You discovered a sea monster.

 MUSIC

LAUREN: So you think about a lot of whales, they kind of sound like that, but it's just not whaley enough. (laughter)

AMY: As it turns out, it was whaley enough. Lauren later learned it is some sort of baleen whale. So far, the species is undetermined. 

MUSIC

AMY: So step one is identification—who’s talking. Or…moaning. But then the question becomes: what are they trying to say? Lauren says fish use sounds to communicate in all kinds of contexts: breeding, feeding, raising the alarm….

LAUREN: Aggregation...calling each other to come together essentially.

AMY: Like, party over here?

LAUREN: Yeah, pretty much. Or, let's stay in a group so we don't all get eaten. (laughter) Who's in the middle? Dave, you in the middle?

AMY: These collective communications are what really captivates Lauren. They're called fish choruses.

UNKNOWN FISH CHORUS 

BLACKSPOTTERD CROAKER CHORUS 

LAUREN: Fish choruses happen when lots and lots and lots of fish all call at the same time. And they produce sound continuously and in doing so they can dominate soundscapes. So it's a big acoustic event.

BLACKSPOTTED CROAKER CHORUS 

BROWN MEAGER CHORUS 

AMY: Fish choruses are the rock concerts of the marine world. They can actually be louder than rock concerts, or airplanes taking off. People in Malaysia, Thailand and other countries have traditions of listening out for fish choruses, to help them figure out where to drop their lines and nets. This is a chorus of eels, which I would definitely rather not encounter while I’m out for a swim.

EEL CHORUS 

STRIPED CUSK-EEL

UNKNOWN CHORUS

AMY: These choruses happen all over the world, among a wide variety of species. Some fish chorus a few times a year, in sync with the seasons. Other kinds of fish make choruses as part of their daily commute between different layers of ocean water.

LAUREN: What happens every evening is fish move up from the depths up to the surface to feed at night time.

MULLOWAY CHORUS 

LAUREN: There'll sort of be this lead up to the chorus. They start getting a little bit closer together, more animals start chiming in, sort of like being like, oh you're calling, I'm going to start. And it just builds and builds and builds until there's so many fish calling that it just can sound like just white noise.

MULLOWAY CHORUS  

LAUREN: So they feed, feed, feed, feed over through the night and then they drop back down around dusk. And then, you know, happens again the next night. It's actually the world's largest migration. It's huge.

MUSIC

AMY: The sounds of these mass migrations can tell us things about how the fish themselves are doing, obviously. But not only that. A fish chorus is almost like a secret language that can tell us other things going on in the ocean too.

LAUREN: Things like temperature, moon phase, tidal range, salinity. So again, the rhythms of these are intrinsically linked to how the ocean is working, essentially. So we can actually use these as indicators for what's happening environmentally over large, large areas, which is really, really useful.

AMY: When you just said moon phase, I'm like, Wait a minute, do fish howl at the moon? That is the coolest thing ever.

LAUREN: Well actually, if you put it that way. Yes, some of them do, yeah.

AMY: One of my favorite terrestrial animal sounds is when a group of coyotes lifts their voices in chorus, filling up the stillness of the night.

COYOTES

AMY: And I love knowing that as these families of furry mammals throw back their heads and sing into the darkness, somewhere, thousands of miles away in the ocean, groups of fish might be doing the same thing. In their way. 

COYOTES

BLACKSPOTTED CROAKER CHORUS (Parsons)

AMY: And of course, people have always responded to the waxing and waning of the moon too. The turning of the seasons. Sunrises and sunsets. Just like the fish, these transitional times are often when we gather, and sing. The rhythms of human culture are resting on patterns that stretch way back in time and way down into the ocean. And down into rivers and lakes, too.

SOUND: WINDY LAKE

AMY: Back in Sweden, after a thirty-minute ski on the lake, Sigge and I have returned to the place where I left the hydrophone. I pull it up—

AMY: And it's out. Nej, nej. That's the sound of a dog licking a hydrophone.

AMY: —and tuck the gear away. Phase one of my listening experiment is over, now it's time to go inside, put a log on the fire, and listen back, to hear if anyone decided to swim up to the mic, and say hello.

We'll find out after this short break.

Break

[19:45] SEGMENT B

AMY: Welcome back to Threshold, I'm Amy Martin, and I have a little challenge for you: as you move through your next few days, see if you can identify spaces you live in close proximity to, but that you can’t actually access. Like, inside the walls of your house or apartment. Or maybe a locked closet at your office or school. For me, one of these places is the dark layer of water under this frozen lake. It’s just beneath my feet, but I’m cut off from it. Sure I could dip in and out, but it’s not like I can actually hang out down there. But when I pull up the recording I made on my computer, and put on my headphones, it’s the closest I’ve ever been to being there. Inside, that cold, quiet world.

QUIET LAKE

AMY: Again, this was early spring, 70 miles below the Arctic circle. For much of the winter, the Sun barely crosses the horizon here. So I don’t expect any fish in this lake to be feeling very chatty.

 QUIET LAKE

AMY: But then, faintly, I hear something.

 DISTANT FISH NOISE

AMY: It's very subtle, but it's definitely there. Something is talking.

CLOSER FISH NOISE

AMY: The sound gets louder as the fish gets closer. I can picture it swimming toward the hydrophone, wondering what this odd thing in the water could be. And then it swims right up to the hydrophone and introduces itself.

CLOSEST FISH NOISE

AMY: And I feel…sort of honored. Someone decided to talk to me! Now this lake doesn't just have some fish in it. It has this fish. This animal that survived here, under the ice, all winter long. It was a moment of contact, not just with this creature, but with a whole world that in many ways feels alien to me, even though it's right there, right under the surface.

MUSIC

AMY: I actually think this might be the most important use of this kind of listening—the way it expands our capacity to connect with our planet mates. But beyond that, what can I do with this fish sound I've recorded? If I was a scientist studying fish, or this ecosystem overall, why would I go to the trouble to make an underwater recording?

MILES: Ahm, there's a number of reasons. So purely listening to all of the diverse that the rich sounds that you've got provides you with a measure of the health of that area.

AMY: I'm back in Perth, Australia talking with Dr. Miles Parsons now. He's a researcher with the Australian Institute of Marine Science. I talked to him the morning after he'd flown back to Australia from the UK, where he grew up, and he was, understandably, tired.

MILES: Last time I was tired in an interview I told them I was going to do a Christmas album of fish calls.

AMY: Can you do a little demo of that?

MILES: No! (laughter)

AMY: I think this is a brilliant idea. Do it Miles. But collecting sounds for what would definitely be a hit album is just one of many reasons to record the sounds of fish.

MILES: You can start to get an idea of what is the essential fish habitat that they're going to, how many of them are going there, and what else is driving them being there.

AMY: Fish sounds can help tell us if an area’s been overfished, or polluted—or on the road to recovery.

MILES: You go from completely dead—no sounds—to healthy, lots of different sounds. So if we can tease out what's going on in that sliding scale in between, then you've got a nice metric of being able to monitor biodiversity and health.

AMY: So if I was doing a study of that Swedish lake, my recording could become one little tile in a mosaic of sonic information that together would help tell the story of its history, its future, and its current state of health. But only if I can identify which species of fish responded to my request for an interview. Was it a grayling? A perch? An Arctic char? Miles says scientists need new tools to help them answer these kinds of questions.

MILES: So in an ideal world you'd have something that would be the equivalent of Shazam for music.

AMY: Shazam is an app that you can use to identify music. You hold your phone up, record a few seconds of a song, and it spits out a title. And it's usually right.

MILES: The analog for science is you have say, I-Naturalist, where you take a photo of a plant, it shows you what the plant is. Or BirdNet. You can record a bird or you can try and do an impression of a bird, and it will tell you what probability it is of what species.

AMY: Another great bird sound app is called Merlin. Miles is working on a project that might someday allow us to do the same thing with fish. It's called...

MILES: The Global Library of Underwater Biological Sounds. GLUBS.

AMY: (laughter)

MILES: Which is...onomatopoeically, I think it's fantastic.

AMY: It's brilliant! It's truly brilliant.

MILES: I love it. There were two of us that independently came up with that acronym. I mean, it it does kind of lend itself, anyway. We were looking at creating a reference library and we were all focused on underwater biological sounds.

AMY: Researchers from close to thirty institutions around the world are involved in GLUBS. Miles says this kind of platform is needed to help collect and organize the massive number of sounds that are now being recorded all over the globe.

MILES: There's a lot of things that have happened recently. The sensors that we used to have back in, let's say, 2000, you'd be going out recording with, say, your handheld recorder and a DAT tape and recording for one or two hours. And now you can find a recorder that will go out, you can deploy it, and it can record for six months or so, even a year, and pick up a wealth of data. And it may be a quarter of the price.

AMY: The quality of the audio we're able to record has also grown exponentially. So we can now record in more places, for longer periods of time, in much higher fidelity than ever before. And that means it's possible to conceive of a day when we have good recordings of all the fish on Earth.

MILES: Now that's going to take a while.

AMY: Again, scientists have so far documented that about a thousand fish species make sound, out of around twelve hundred studied.

MILES: We expect somewhere between fifteen and twenty-five thousand species of fish produce sound of some kind. So we've got a long way to go.

AMY: But recording all of this sound is one thing, using it is another. In just thirty minutes, I captured quite a few sounds in that Swedish lake. If I were a scientist, each of those sounds would need to be identified, labeled, organized, stored. And thirty minutes is nothing, really. What if I had thirty hours of recordings, or three thousand? It wouldn't take long for me to record more acoustic data than I could ever listen to. This is the situation that a lot of bioacoustics researchers are in right now: the rate at which we’re able to acquire data has far outpaced the rate at which we can process it.

MILES: We're moving into an era where artificial intelligence can start to analyze these huge volumes of data that we're collecting.  

AMY: Scientists are already using AI to search through thousands of hours of recordings at lightning speed, and say: here are all the sounds that seem to be alike.

MILES: And then we can build up these data sets that AI algorithms can then search for in other recordings. But that will take time.

AMY: Later this season, we'll learn about efforts to use AI to actually decode what other animals are saying, kind of like the universal translator in Star Trek, but for dogs or dolphins. But we can't translate a voice we've never heard, or never paid attention to. Someone still needs to do the foundational work of pairing the singers with the song. That's why researchers like Lauren Hawkins are manually listening through recordings; making notes, talking to other researchers, helping to assemble an accurate reference catalog of sounds.

LAUREN: I'm at the real basic stages of just being like, that's a fish chorus that that was found there, these are the parameters of what it looks like, and this is what it does. Okay, that's one. And then the next and then the next one and the next one in the next one. But that's a really good foundation for someone to then go in and go, well, how does this fish chorus change over time?

AMY: Then we ask questions about things like population size and health, changes in ocean currents, the status of associated predators and prey—including the highest-impact predator in the sea, us. Overfishing is the biggest global threat these animals face. Simply put, we're pulling fish out of the water much faster than they can reproduce. It's an unsustainable level of consumption, with a host of complex factors at play, from illegal fishing, harmful fishing practices, wasteful bycatch, and more. And that's before we even get into climate, pollution, and other impacts. Lauren says all of this brings real urgency to her work.

LAUREN: So by the time we get our hydrophones out, you know, what used to be there might not be there anymore. So it's really important that we start getting those baselines. But then we also use that to inform how we need to monitor into the future.

MUSIC

AMY: It's not all about tracking problems, she says. It's also about measuring success. If we try out a new management strategy in the effort to bring a fish species back from decline, and it works, then when we need to know that.

LAUREN: We've got to have some way to measure it. And you don't know you've won unless you've got a  score. So we've got to somehow have a score. And using acoustics and using fish is a way of scoring it.

AMY: So fish sounds can be put to use in very concrete, specific projects. But they can also be part of the larger quest of our era: bringing ourselves into better relationship with our planet-mates. 

MUSIC

AMY: As mammals we bond most deeply with other mammals. Even species that look really different from us—like whales or elephants—form relationships that we recognize and  can relate to.

LAUREN: So you already have that sort of emotional connection and you can empathize with the plight of these animals.

AMY: Fish are different. And often, we tend to turn away from difference—to recoil from it, or fill the gap with assumptions and fictions. We tell ourselves that fish are stupid. Or that they don't feel pain. But Lauren says  it's not so easy to disregard fish when you listen to them.

LAUREN: These animals are, they are communicating. They are animals. They have a life. You know, if they're animals that can talk to each other during their daily lives. They're communicating. There is intelligence there.

AMY: Maybe fish pose a special challenge to our intelligence. Are we smart enough to drop our preconceptions, and comprehend the sounds they make on their own terms?

MUSIC

AMY: Lauren’s hopeful that bioacoustics can be more than a scientific tool; that it can open people up to the wonder of the conversations happening around us all the time. Not only among fish, but all kinds of creatures.

LAUREN: I love the research that I do. I could easily do it for the rest of my life because it's just this something new every single time. I never, I never lose that sense of, like, how lucky I am to be able to listening in and to hear things that people don't hear and people don't know. Like there's recording locations close to shore, which people use very regularly, and I'm like, you would have no idea that underneath the surface there's a blue whale going past, and there's, you know, fin whales, and there's humpback whales, you know, screaming around…

AMY: And these fish choruses.

LAUREN: And these fish choruses. Yeah, these guys are calling, and all this life is happening that, yeah, if you didn't pop your head down in the water you wouldn't know.

MUSIC + FISH

MILES: There are an amazing variety of different sounds that are absolutely fantastic. I've played piano from like four years old, so I have a strong connection to music. And as far as I'm concerned, the fish noises, and the marine noises, and soundscape is all a form of music.

AMY: There are few things more comforting than understanding another person and feeling understood. We can pick familiar voices out of a crowd—we're hard-wired to pay attention to communication from those we know and love. But talking to Lauren and Miles, and feeling their excitement about tuning in to creatures who communicate so differently from us, makes me wonder if we're also hard-wired for listening across huge divides. Yes, we humans can be close-minded, and arrogant, and fearful of the unknown. But we can also find connection, and sheer delight in the mystery of the unks and boops and kwas.

CREDITS

AMY: This episode of Threshold was written, reported, and produced by me, Amy Martin, with help from Erika Janik and Sam Moore. Music by Todd Sickafoose. Post-production by Alan Douches. Fact-checking by Sam Moore. Special thanks to Lauren Hawkins, Miles Parsons, and Tim Lamont for many of the fish recordings you heard in this episode. Clara Amorim and Raquel Vasconcelos recorded that Lusitanian toadfish, Herbert Tiepelt recorded the pikeperch percussionist, and Marta Bolgan provided the “unknown kwa” I love so much. Additional recordings came from more than a dozen other scientists, many of whom have contributed sounds to the website FishSounds.net. Check the show notes or our website for links to many of these sounds and the scientists who recorded them. This show is made by Auricle Productions, a non-profit organization powered by listener donations. Deneen Wiske is our executive director. You can find more about our show at thresholdpodcast.org.