Amy Martin: 00:00:00

The time is a few 100 million years ago. The place

Amy Martin: 00:00:05

is the ocean, any ocean, and you are a fish, one of the planet's

Amy Martin: 00:00:11

first vertebrates. You have emerged into a very quiet world.

Amy Martin: 00:00:18

There's the snap and crackle shrimp and other invertebrates,

Amy Martin: 00:00:22

but usually the loudest sound in the sea is the water itself,

Amy Martin: 00:00:27

washing up against your fins and scales. But then one day, you

Amy Martin: 00:00:34

feel it, an urge to be heard, to declare your presence. You

Amy Martin: 00:00:40

squeeze the muscles around the little balloon inside your body,

Amy Martin: 00:00:44

your swim bladder, and a call rings out into the darkness, and

Amy Martin: 00:00:53

to your surprise, somebody calls back.

Amy Martin: 00:01:05

Fish were among the first marine animals to use sound for

Amy Martin: 00:01:09

communication. Of course, this ability evolved gradually, not

Amy Martin: 00:01:14

all at once, like I was playing with here, but still, after more

Amy Martin: 00:01:18

than 4 billion years of very quiet oceans, fish began to fill

Amy Martin: 00:01:24

the sea with their voices. It was the dawn of a new era, the

Amy Martin: 00:01:29

birth of dialog, conversations made of clicks and thumps,

Amy Martin: 00:01:34

croaks and whoops and whatever you'd call this.

Lauren Hawkins: 00:01:41

Ah, this is my favorite one.

Amy Martin: 00:01:44

Welcome to Threshold, I'm Amy Martin, and

Amy Martin: 00:01:46

this is marine biologist Lauren Hawkins.

Lauren Hawkins: 00:01:49

So just like many other animals in the ocean

Lauren Hawkins: 00:01:52

that we know of, like whales and dolphins, fish also produce

Lauren Hawkins: 00:01:55

sound to communicate.

Amy Martin: 00:01:58

This season, we're listening to our fellow

Amy Martin: 00:02:01

earthlings, roughly in the order in which they evolved. And fish

Amy Martin: 00:02:05

are way, way back in that timeline, after microbes, corals

Amy Martin: 00:02:10

and some other invertebrates, but long before almost

Amy Martin: 00:02:13

everything else. And the earlier a creature emerged in that

Amy Martin: 00:02:18

story, the wider the gap between them and us, at least in our own

Amy Martin: 00:02:23

minds. But Lauren says listening to fish communicate, even just

Amy Martin: 00:02:28

knowing that they can and do communicate, starts to open up a

Amy Martin: 00:02:32

portal between our two worlds.

Lauren Hawkins: 00:02:35

Yeah, listening to fish has definitely given me

Lauren Hawkins: 00:02:38

a very different view into how to value life other than human

Lauren Hawkins: 00:02:44

life.

Amy Martin: 00:02:45

Fish are an essential food source for

Amy Martin: 00:02:48

everything from otters to osprey to the dolphins we met in our

Amy Martin: 00:02:52

last episode, and for us humans too. A world without fish would

Amy Martin: 00:02:57

be a world in which food webs collapse and billions of people

Amy Martin: 00:03:01

go hungry, so it is very much in our own interest to pay

Amy Martin: 00:03:06

attention to what they have to say. But also, fish are our

Amy Martin: 00:03:12

neighbors. They don't look like us or act much like us, but that

Amy Martin: 00:03:16

doesn't mean they're not worth getting to know. In fact, those

Amy Martin: 00:03:20

differences are a big part of what makes fish conversation so

Amy Martin: 00:03:24

fascinating and useful. These animals have stories to tell

Amy Martin: 00:03:29

about some of the parts of our planet that are the most

Amy Martin: 00:03:32

mysterious to us. In this episode, we're going to meet

Amy Martin: 00:03:36

people who are figuring out how to listen to these fish tales

Amy Martin: 00:03:40

and learn from them.

Amy Martin: 00:04:09

It's early spring, and I'm standing on a frozen lake in

Amy Martin: 00:04:13

northern Sweden. The ice is at least two feet thick, maybe

Amy Martin: 00:04:17

three, but I know there's a little hole drilled through it

Amy Martin: 00:04:20

here somewhere, hiding under a thin layer of crusty snow. I'm

Amy Martin: 00:04:24

using my cross country ski pool to find it.

Amy Martin: 00:04:27

Ah, there it went.

Amy Martin: 00:04:29

This is an ice fishing hole just big enough to drop a line down

Amy Martin: 00:04:32

into. But I have a different purpose in mind.

Amy Martin: 00:04:35

I'm going to hook up a hydrophone, which is basically

Amy Martin: 00:04:39

just a microphone at the end of a long waterproof cord, and the

Amy Martin: 00:04:44

microphone itself is waterproof, and I'm gonna plunk it down

Amy Martin: 00:04:47

there into this very cold lake and see if we can hear any fish

Amy Martin: 00:04:51

or any other signs of life.

Amy Martin: 00:04:55

So what you're listening to here is the beginning of a passive

Amy Martin: 00:04:58

acoustic monitoring session. That sounds kind of fancy, but

Amy Martin: 00:05:03

it's not. The basic idea is you take a microphone, connect it to

Amy Martin: 00:05:07

a recorder, and leave it running while you exit the scene.

Amy Martin: 00:05:12

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

Amy Martin: 00:05:15

My technical assistant for the day is a handsome fellow named

Amy Martin: 00:05:20

Sigge with big brown eyes, a distinctive profile and a strong

Amy Martin: 00:05:24

desire to chew on my gear. As I lower the hydrophone down into

Amy Martin: 00:05:29

the lake, he decides to do some energetic digging up on the

Amy Martin: 00:05:33

surface, and I can hear every scratch of his paws through the

Amy Martin: 00:05:37

hydrophone. It's shocking how well the sound translates down

Amy Martin: 00:05:42

into the water through this thick layer of ice. It makes me

Amy Martin: 00:05:46

realize that every noise we make up here on the surface impacts

Amy Martin: 00:05:50

the acoustic environment in the water below.

Amy Martin: 00:05:53

You're being very helpful with this recording Sigge.

Amy Martin: 00:05:59

I cover up the recorder in case it starts to snow, clip into my

Amy Martin: 00:06:04

cross country skis and head out across the lake. I want to get

Amy Martin: 00:06:09

myself and my dog as far away from the microphone as I can so

Amy Martin: 00:06:13

none of our noise interferes with whatever might feel like

Amy Martin: 00:06:16

coming in to visit. We'll check back later to see if anyone

Amy Martin: 00:06:20

decided to talk.

Amy Martin: 00:06:26

Fish live almost everywhere we find water, and that's 70% of

Amy Martin: 00:06:31

the surface of the earth. We are utterly dependent on these

Amy Martin: 00:06:36

aquatic parts of our planet, but many of them are really hard to

Amy Martin: 00:06:39

access, like the dark, frigid layer of water under a frozen

Amy Martin: 00:06:43

lake or the depths of the ocean. Lauren Hawkins says fish can

Amy Martin: 00:06:48

serve as emissaries from those places.

Lauren Hawkins: 00:06:51

We have to find ways to monitor the health of

Lauren Hawkins: 00:06:54

our marine environments, and fish are very good indicators

Lauren Hawkins: 00:06:57

for that.

Amy Martin: 00:06:58

I visited Lauren at Curtin University in Perth,

Amy Martin: 00:07:01

Australia, while she was working on her PhD in fish acoustics.

Lauren Hawkins: 00:07:05

Acoustically, we know very little. We hear all

Lauren Hawkins: 00:07:09

these sounds, and we're like, oh, yeah, that sort of is most

Lauren Hawkins: 00:07:13

likely a fish because it's got these characteristics. But we

Lauren Hawkins: 00:07:18

don't 100% know, and we also don't know what fish they are.

Amy Martin: 00:07:23

People have known that fish make sounds for a very

Amy Martin: 00:07:27

long time. You can see it in the names we've given some of them:

Amy Martin: 00:07:31

croakers, grunts, trumpeters. But even so, Lauren says people

Amy Martin: 00:07:36

are often confused when she tells them she studies fish

Amy Martin: 00:07:39

acoustics. We don't really think about fish making sounds. In

Amy Martin: 00:07:44

fact, many people, myself included, don't think about fish

Amy Martin: 00:07:49

that much at all. Lauren says we don't even know precisely how

Amy Martin: 00:07:54

many fish species exist on Earth.

Lauren Hawkins: 00:07:56

Yeah, and you know so much of the ocean is

Lauren Hawkins: 00:07:59

still unexplored. We're still finding new species of fish.

Amy Martin: 00:08:02

That surprised me. I mean, I'm as interested in

Amy Martin: 00:08:05

finding extraterrestrial life as the next person, but we don't

Amy Martin: 00:08:09

even know all the life forms we have on this planet. So one of

Amy Martin: 00:08:14

the many uses of passive acoustic monitoring is just

Amy Martin: 00:08:17

answering the basic question of what animals live on Earth, and

Amy Martin: 00:08:22

once we know who's talking, we can start to ask about what

Amy Martin: 00:08:26

they're saying and how they're saying it, and why. Lauren says

Amy Martin: 00:08:30

there are two main ways that fish produce sound.

Lauren Hawkins: 00:08:33

So the first is through sort of strumming or

Lauren Hawkins: 00:08:37

stridulation of bony body parts. So that's like, you know, they

Lauren Hawkins: 00:08:40

flick their fin rays against their pectoral girdle and things

Lauren Hawkins: 00:08:43

like that.

Amy Martin: 00:08:46

That's a freshwater fish known as a zander, or a

Amy Martin: 00:08:49

pike perch, doing this kind of percussive sound-making.

Lauren Hawkins: 00:08:54

But the second is using their swim bladder, and

Lauren Hawkins: 00:08:58

they use it as sort of like a resonator. So there's like sonic

Lauren Hawkins: 00:09:02

muscles that contract the swim bladder, and it produces a range

Lauren Hawkins: 00:09:09

of different noises.

Amy Martin: 00:09:11

That is a Lusitanian toadfish making a sound that

Amy Martin: 00:09:15

scientists call a boat whistle, which is not the first thing

Amy Martin: 00:09:19

that came to mind when I heard it.

Amy Martin: 00:09:30

Swim bladders are internal sacks that help fish swim, or at least

Amy Martin: 00:09:35

float. They're filled with air, and most living fish species

Amy Martin: 00:09:40

have them by letting air in and out of the bladders. Fish can

Amy Martin: 00:09:44

move up and down in the water. People have swim bladders too,

Amy Martin: 00:09:49

sort of. We call them lungs, and when we're in the water, we can

Amy Martin: 00:09:54

also use them to help control our buoyancy. We are actually

Amy Martin: 00:09:58

descendants of a branch of very early fish that never developed

Amy Martin: 00:10:03

swim bladders. Instead, they held onto their proto lungs, and

Amy Martin: 00:10:07

some of them evolved into the creatures that eventually

Amy Martin: 00:10:10

crawled up out of the sea and became the first vertebrates on

Amy Martin: 00:10:13

land. But that part of the story comes way later. For millions of

Amy Martin: 00:10:19

years, fish were the most complex life forms on the

Amy Martin: 00:10:22

planet, and likely the noisiest. When scientists record these

Amy Martin: 00:10:29

sounds, they give them fun names like sneaks, unks, snorts and

Amy Martin: 00:10:34

boops. This is one of my favorites, an unknown fish

Amy Martin: 00:10:39

creating its own little dance rhythm using a sound that

Amy Martin: 00:10:42

someone called a kwa.

Amy Martin: 00:10:51

The total number of fish species identified so far is around

Amy Martin: 00:10:55

35,000. Only about 1200 of those have been studied to see if they

Amy Martin: 00:11:01

produce sounds, but of those, more than 80% do. And that means

Amy Martin: 00:11:07

there are tons of species of fish out there whose voices we

Amy Martin: 00:11:10

either haven't heard yet or we can't yet identify.

Lauren Hawkins: 00:11:14

And even this morning, for example, I'm

Lauren Hawkins: 00:11:16

looking at a new data set, and I was like, what is that sound?

Lauren Hawkins: 00:11:21

I've never seen that sound before, and I was like, calling

Lauren Hawkins: 00:11:23

everyone in I'm like, whale people. Is this a whale sound?

Lauren Hawkins: 00:11:27

Like, is this a fish? Is this a whale? We don't know. So it's a

Lauren Hawkins: 00:11:30

privilege to be able to eavesdrop and actually be like,

Lauren Hawkins: 00:11:35

wow, what's, what's, what's happening here?

Amy Martin: 00:11:39

If an alien civilization wanted to study

Amy Martin: 00:11:41

human communication, they could scoop us up into their

Amy Martin: 00:11:44

spaceships and see how we react to different stimuli. Or they

Amy Martin: 00:11:50

could drop microphones down into our various habitats without

Amy Martin: 00:11:53

being detected, presumably, and just listen to us being human on

Amy Martin: 00:11:59

our farms, in our villages, in big, bustling cities. Scientists

Amy Martin: 00:12:05

interested in fish sounds face a similar choice. They can pull

Amy Martin: 00:12:10

animals out of the water and do things to them, often unpleasant

Amy Martin: 00:12:14

things to trigger responses. But Lauren says she was drawn to

Amy Martin: 00:12:19

passive acoustic monitoring because it opened up a different

Amy Martin: 00:12:22

way of getting to know these creatures.

Lauren Hawkins: 00:12:25

I wanted to be able to look at the natural

Lauren Hawkins: 00:12:28

world in a way where I didn't have to interfere with the

Lauren Hawkins: 00:12:31

animals. I didn't have to get in the water with them. I didn't

Lauren Hawkins: 00:12:34

have to take things out of the water and mess with them and

Lauren Hawkins: 00:12:38

things like that.

Amy Martin: 00:12:41

Taking this more receptive role means we get to

Amy Martin: 00:12:44

hear the sounds fish make when they're out there in the world

Amy Martin: 00:12:47

being fish, which is very different from anything that can

Amy Martin: 00:12:51

be produced in a lab.

Lauren Hawkins: 00:12:53

Acoustics is a really amazing way of, sort of

Lauren Hawkins: 00:12:56

seeing into their private lives that you usually wouldn't know

Lauren Hawkins: 00:12:59

anything about, and give you clues as to you know how they're

Lauren Hawkins: 00:13:04

going about their daily lives and what things are associated

Lauren Hawkins: 00:13:08

with that.

Amy Martin: 00:13:10

Lauren says all kinds of surprising things crop

Amy Martin: 00:13:12

up.

Lauren Hawkins: 00:13:13

This is the sound that I found this morning.

Lauren Hawkins: 00:13:16

And was like, what is this?

Amy Martin: 00:13:18

She pulls up the mystery sound on her computer so

Amy Martin: 00:13:21

we can listen to it.

Amy Martin: 00:13:22

Where was this recorded?

Lauren Hawkins: 00:13:23

This is recorded in South Australia.

Amy Martin: 00:13:26

And you just got this data.

Lauren Hawkins: 00:13:28

I just, well, I've had it for a while, but

Lauren Hawkins: 00:13:30

I've just processed it, but this is the first time I've looked at

Lauren Hawkins: 00:13:32

it.

Amy Martin: 00:13:33

Lauren gives me her headphones and hits play. At

Amy Martin: 00:13:36

first, I don't hear anything, but underwater hiss.

Lauren Hawkins: 00:13:41

So it's very low frequency.

Amy Martin: 00:13:44

But then out of that noise, a signal emerges.

Amy Martin: 00:13:52

Oh, do it again? That's so cool.

Lauren Hawkins: 00:13:58

Yeah, I know right, but I have no idea what

Lauren Hawkins: 00:13:59

it is.

Amy Martin: 00:14:00

It's a monster!

Lauren Hawkins: 00:14:01

It is.

Amy Martin: 00:14:01

You just discovered a sea monster.

Lauren Hawkins: 00:14:05

So you think about a lot of whales, they kind

Lauren Hawkins: 00:14:08

of sound like that, but it's just not whaley enough.

Amy Martin: 00:14:13

As it turns out, it was whaley enough. She learned

Amy Martin: 00:14:16

later it's some sort of baleen whale. So far, the species is

Amy Martin: 00:14:20

undetermined. So step one here is identification. Who's talking

Amy Martin: 00:14:27

or moaning. But then the question becomes, what are they

Amy Martin: 00:14:31

trying to say? Lauren says fish use sounds to communicate in all

Amy Martin: 00:14:36

kinds of contexts, breeding, feeding, raising the alarm.

Lauren Hawkins: 00:14:41

Aggregation, calling each other to come

Lauren Hawkins: 00:14:44

together, essentially, yeah.

Amy Martin: 00:14:46

Party over here?

Lauren Hawkins: 00:14:47

Yeah, pretty much, yeah, or let's stay in a

Lauren Hawkins: 00:14:50

group so we don't all get eaten. Who's in the middle? Dave, are

Lauren Hawkins: 00:14:54

you in the middle?

Amy Martin: 00:14:59

These collective communications are what really

Amy Martin: 00:15:02

captivates Lauren. They're called fish choruses.

Lauren Hawkins: 00:15:07

Fish choruses happen when lots and lots and

Lauren Hawkins: 00:15:10

lots of fish all call at the same time, and they produce

Lauren Hawkins: 00:15:14

sound continuously, and in doing so, they can dominate

Lauren Hawkins: 00:15:20

soundscapes. So it's a big acoustic event.

Amy Martin: 00:15:27

Fish choruses are the rock concerts of the marine

Amy Martin: 00:15:30

world. They can actually be louder than rock concerts or

Amy Martin: 00:15:34

airplanes taking off. People in Malaysia, Thailand and some

Amy Martin: 00:15:38

other countries, have traditions of listening out for fish

Amy Martin: 00:15:41

choruses to help them figure out where to drop their lines and

Amy Martin: 00:15:45

nets. This is a chorus of eels which I would definitely rather

Amy Martin: 00:15:50

not encounter while I'm out for a swim.

Amy Martin: 00:15:52

These choruses happen all over the world among a wide variety

Amy Martin: 00:16:02

of species. Some fish chorus a few times a year, in sync with

Amy Martin: 00:16:06

the seasons. Other kinds of fish make choruses as part of their

Amy Martin: 00:16:09

daily commute between different layers of ocean water.

Lauren Hawkins: 00:16:13

What happens every evening is fish move up

Lauren Hawkins: 00:16:18

from the depths up to the surface to feed at night time.

Lauren Hawkins: 00:16:23

There'll sort of be this lead up to the chorus. They start

Lauren Hawkins: 00:16:27

getting a little bit closer together, more animals start

Lauren Hawkins: 00:16:31

chiming in, sort of like being like, oh, you're calling, I'm

Lauren Hawkins: 00:16:34

gonna start. And it just builds and builds and builds until

Lauren Hawkins: 00:16:38

there's so many fish calling that it just can sound like a

Lauren Hawkins: 00:16:42

just white noise.

Lauren Hawkins: 00:16:50

So they feed, feed, feed, feed, over through the night, and then

Lauren Hawkins: 00:16:54

they drop back down around dusk, and then happens again the next

Lauren Hawkins: 00:16:58

night. It's actually the world's largest migration. It's huge.

Amy Martin: 00:17:04

The sounds of these mass migrations can tell us

Amy Martin: 00:17:07

things about how the fish themselves are doing, obviously.

Amy Martin: 00:17:10

But not only that. A fish chorus is almost like a secret language

Amy Martin: 00:17:15

that can tell us other things going on in the ocean too.

Lauren Hawkins: 00:17:18

Things like temperature, moon phase, tidal

Lauren Hawkins: 00:17:22

range, salinity. So again, the rhythms of these are

Lauren Hawkins: 00:17:27

intrinsically linked to how the ocean is working, essentially.

Lauren Hawkins: 00:17:31

So we can actually use these as indicators for what's happening

Lauren Hawkins: 00:17:34

environmentally over large areas, which is really, really

Lauren Hawkins: 00:17:37

useful.

Amy Martin: 00:17:38

You just said moon phase. I'm like, wait a minute.

Amy Martin: 00:17:42

Do fish howl the mood? That is the coolest thing ever.

Lauren Hawkins: 00:17:47

Well, actually, if you put it that way, yes,

Lauren Hawkins: 00:17:49

some of them do.

Amy Martin: 00:17:52

One of my favorite terrestrial animal sounds is

Amy Martin: 00:17:57

when a group of coyotes lifts their voices in chorus, filling

Amy Martin: 00:18:01

up the stillness of the night. And I love knowing that as these

Amy Martin: 00:18:08

families of furry mammals throw back their heads and sing into

Amy Martin: 00:18:13

the darkness, somewhere, thousands of miles away in the

Amy Martin: 00:18:17

ocean, groups of fish might be doing the same thing, in their

Amy Martin: 00:18:21

way.

Amy Martin: 00:18:22

And of course, people have always responded to the waxing

Amy Martin: 00:18:37

and waning of the moon too and the turning of the seasons,

Amy Martin: 00:18:41

sunrises and sunsets, just like the fish, these transitional

Amy Martin: 00:18:46

times are often when we gather and sing. The rhythms of human

Amy Martin: 00:18:51

culture are resting on patterns that stretch way back in time

Amy Martin: 00:18:57

and way down into the ocean and down into rivers and lakes too.

Amy Martin: 00:19:05

Back in Sweden, after a 30-minute ski on the lake, Sigge

Amy Martin: 00:19:09

and I have returned to the place where I left the hydrophone. I

Amy Martin: 00:19:12

pull it up...

Amy Martin: 00:19:15

That's the sound of a dog licking a hydrophone.

Amy Martin: 00:19:17

...And tucked the gear away. Phase one of my listening

Amy Martin: 00:19:21

experiment is over. Now it's time to go inside, put a log on

Amy Martin: 00:19:25

the fire and listen back to hear if anyone decided to swim up to

Amy Martin: 00:19:29

the mic and say hello. We'll find out after this short break.

Dallas Taylor: 00:19:36

Hi, I'm Dallas Taylor, host of 20,000 Hertz, a

Dallas Taylor: 00:19:48

podcast that reveals the untold stories behind the sounds of our

Dallas Taylor: 00:19:51

world. We've uncovered the incredible intelligence of

Dallas Taylor: 00:19:54

talking parrots.

Dallas Taylor: 00:19:55

Basically, bird brain was a pejorative term, and here I had

Dallas Taylor: 00:20:00

this bird that was doing the same types of tasks as the

Dallas Taylor: 00:20:03

primates.

Dallas Taylor: 00:20:05

We've investigated the bonding power of music.

Unknown: 00:20:07

There's an intimacy there in communicating through

Unknown: 00:20:10

the medium of music that can be really a powerful force for

Unknown: 00:20:15

bringing people together.

Dallas Taylor: 00:20:16

We've explored the subtle nuances of the human

Dallas Taylor: 00:20:19

voice.

Unknown: 00:20:19

We have to remember that humans, over many hundreds

Unknown: 00:20:22

of thousands of years of evolution, have become extremely

Unknown: 00:20:25

attuned to the sounds of each other's voices.

Dallas Taylor: 00:20:28

And we'ce revealed why a famous composer

Dallas Taylor: 00:20:30

wrote a piece made entirely of silence.

Unknown: 00:20:33

I think that's a really potentially quite useful and

Unknown: 00:20:36

quite profound experience to have.

Dallas Taylor: 00:20:38

Subscribe to 20,000 Hertz right here in your

Dallas Taylor: 00:20:41

podcast player. I'll meet you there.

Amy Martin: 00:20:44

Hey, I want to take a minute to thank you for

Amy Martin: 00:20:46

listening to Threshold and to explain how important you are in

Amy Martin: 00:20:50

getting the show made. Most podcasts raise money by selling

Amy Martin: 00:20:54

advertising, and that pushes them to make a lot of episodes

Amy Martin: 00:20:58

as quickly as possible. But that's just not who we are. Our

Amy Martin: 00:21:03

show is about thinking deeply about how humans are fitting

Amy Martin: 00:21:07

into the rest of the web of life. We take you places and

Amy Martin: 00:21:11

craft stories that are intellectually challenging and

Amy Martin: 00:21:14

emotionally rich. That's the kind of show we want to make,

Amy Martin: 00:21:18

and that's the kind of show you've told us you want to hear.

Amy Martin: 00:21:22

That's why we created an independent, non-profit media

Amy Martin: 00:21:25

company, and why nearly all of our funding comes from listeners

Amy Martin: 00:21:29

like you. This is not the easiest way of funding a show,

Amy Martin: 00:21:35

but it is the way that's most aligned with our mission, and

Amy Martin: 00:21:38

it's worked so far, thanks to people who decide to support it.

Amy Martin: 00:21:44

Our year-end fundraising campaign is happening now

Amy Martin: 00:21:47

through December 31 and each gift will be matched by our

Amy Martin: 00:21:51

partners at NewsMatch. That means, if you can give $25 we'll

Amy Martin: 00:21:56

receive 50. You can make your donation online at

Amy Martin: 00:21:59

thresholdpodcast.org. Just click the donate button and give what

Amy Martin: 00:22:04

you can and again, thank you so much for listening.

Amy Martin: 00:22:17

Welcome back to Threshold, I'm Amy Martin, and I have a little

Amy Martin: 00:22:20

challenge for you: as you move through your next few days, see

Amy Martin: 00:22:25

if you can identify spaces you live in close proximity to but

Amy Martin: 00:22:29

that you can't actually access, like inside the walls of your

Amy Martin: 00:22:34

house or apartment or maybe a locked closet at your office or

Amy Martin: 00:22:38

school. For me, one of these places is the dark layer of

Amy Martin: 00:22:44

water under this frozen lake. It's just beneath my feet, but

Amy Martin: 00:22:48

I'm cut off from it. Sure, I could dip in and out, but it's

Amy Martin: 00:22:53

not like I can actually hang out down there, but when I pull up

Amy Martin: 00:22:57

the recording I made on my computer and put on my

Amy Martin: 00:23:00

headphones, it's the closest I've ever been to being there

Amy Martin: 00:23:04

inside that cold, quiet world. Again, this was early spring, 70

Amy Martin: 00:23:12

miles below the Arctic Circle. For much of the winter, the sun

Amy Martin: 00:23:16

barely crosses the horizon here, so I don't expect any fish in

Amy Martin: 00:23:20

this lake to be feeling particularly chatty. But then

Amy Martin: 00:23:25

faintly I hear something. It's very subtle, but it's definitely

Amy Martin: 00:23:31

there. Something is talking. The sound gets louder as the fish

Amy Martin: 00:23:39

gets closer, I can picture it swimming toward the hydrophone,

Amy Martin: 00:23:43

wondering what this odd thing in the water could be, and then it

Amy Martin: 00:23:48

swims right up to the mic and introduces itself. And I feel

Amy Martin: 00:23:53

sort of honored. Someone decided to talk to me! And now this lake

Amy Martin: 00:24:00

doesn't just have some fish in it. It has this fish. This

Amy Martin: 00:24:05

animal that survived here under the ice all winter long. It was

Amy Martin: 00:24:11

a moment of contact, not just with this creature, but with a

Amy Martin: 00:24:15

whole world that in many ways, feels alien to me, even though

Amy Martin: 00:24:20

it's right there, right under the surface. I actually think

Amy Martin: 00:24:27

this might be the most important use of this kind of listening,

Amy Martin: 00:24:31

the way it expands our capacity to connect with our planet

Amy Martin: 00:24:34

mates. But beyond that, what can I do with this fish sound I've

Amy Martin: 00:24:39

recorded? If I was a scientist studying fish or this ecosystem

Amy Martin: 00:24:44

overall, why would I go to the trouble to make an underwater

Amy Martin: 00:24:48

recording?

Amy Martin: 00:24:50

Dr. Miles Parsons: There's a number of reasons. Purely

Amy Martin: 00:24:51

listening to all of the diverse sounds that you've got provide

Amy Martin: 00:24:55

you with a measure of the health of that area.

Amy Martin: 00:24:57

I'm back in Perth, Australia, talking with Dr.

Amy Martin: 00:25:00

Miles Parsons now. He's a researcher with the Australian

Amy Martin: 00:25:04

Institute of Marine Science. I talked to him the morning after

Amy Martin: 00:25:08

he'd flown back to Australia from the UK, where he grew up,

Amy Martin: 00:25:11

and he was understandably tired.

Amy Martin: 00:25:14

Dr. Miles Parsons: Last time I was tired in an interview, I

Amy Martin: 00:25:16

told him I was going to do a Christmas album made up of fish

Amy Martin: 00:25:18

calls.

Amy Martin: 00:25:19

Can you do a little demo?

Amy Martin: 00:25:20

Dr. Miles Parsons: No.

Amy Martin: 00:25:22

I think this is a brilliant idea. Do it Miles. But

Amy Martin: 00:25:26

collecting sounds for what would definitely be a hit album is

Amy Martin: 00:25:30

just one of many reasons to record the sounds of fish.

Amy Martin: 00:25:34

Dr. Miles Parsons: You can start to get an idea of what is the

Amy Martin: 00:25:36

essential fish habitat that they're going to, how many of

Amy Martin: 00:25:40

them are going there, and what else is driving them being

Amy Martin: 00:25:44

there.

Amy Martin: 00:25:45

Fish sounds can help tell us if an area has been over

Amy Martin: 00:25:48

fished, or if it's polluted, or if it's on the road to recovery.

Amy Martin: 00:25:53

Dr. Miles Parsons: You go from completely dead, no sounds to

Amy Martin: 00:25:56

healthy, lots of different sounds. So if we can tease out

Amy Martin: 00:26:00

what's going on in that sliding scale in between, then you've

Amy Martin: 00:26:04

got a nice metric of being able to monitor biodiversity and

Amy Martin: 00:26:08

health.

Amy Martin: 00:26:09

So if I was doing a study of that Swedish lake, my

Amy Martin: 00:26:12

recording could become one little tile in a mosaic of sonic

Amy Martin: 00:26:16

information that together would help tell the story of its

Amy Martin: 00:26:19

history, its future, its current state of health. But only if I

Amy Martin: 00:26:24

can identify which species of fish responded to my request for

Amy Martin: 00:26:28

an interview. Was it a grayling, a perch, an Arctic char? Miles

Amy Martin: 00:26:33

says scientists need new tools to help them answer these kinds

Amy Martin: 00:26:37

of questions.

Amy Martin: 00:26:38

Dr. Miles Parsons: So in an ideal world, you'd have

Amy Martin: 00:26:40

something that would be the equivalent of Shazam for music.

Amy Martin: 00:26:43

Shazam is an app that you can use to identify

Amy Martin: 00:26:45

music. You hold your phone up record a few seconds of a song,

Amy Martin: 00:26:49

and it spits out a title, and it's usually right.

Amy Martin: 00:26:52

Dr. Miles Parsons: The analog for science is you have say,

Amy Martin: 00:26:56

I-Naturalist, where you take a photo of a plant, it shows you

Amy Martin: 00:26:58

what the plant is. Or BirdNet, you can record a bird, or you

Amy Martin: 00:27:03

can try and do an impression of a bird, and it will tell you

Amy Martin: 00:27:05

what probability it is of what species.

Amy Martin: 00:27:08

Another great bird sound app is called Merlin.

Amy Martin: 00:27:12

Miles is working on a project that might someday allow us to

Amy Martin: 00:27:15

do the same thing with fish. It's called...

Amy Martin: 00:27:18

Dr. Miles Parsons: The Global Library of Underwater Biological

Amy Martin: 00:27:21

Sounds. GLUBS. Which is onomatopoeically, I think it's

Amy Martin: 00:27:25

fantastic.

Amy Martin: 00:27:26

It's brilliant. It's truly brilliant.

Amy Martin: 00:27:28

Dr. Miles Parsons: I love it. There were two of us that

Amy Martin: 00:27:30

independently came up with that acronym. I mean, it does kind of

Amy Martin: 00:27:34

lend itself anyway. We we were looking at creating a reference

Amy Martin: 00:27:39

library, and we're all focused on underwater biological sounds.

Amy Martin: 00:27:43

Researchers from close to 30 institutions around

Amy Martin: 00:27:46

the world are involved in GLUBS. Miles says this kind of platform

Amy Martin: 00:27:51

is needed to help collect and organize the massive number of

Amy Martin: 00:27:55

sounds that are now being recorded all over the globe.

Amy Martin: 00:27:58

Dr. Miles Parsons: There's a lot of things that have happened

Amy Martin: 00:28:00

recently. The sensors that we used to have back in, let's say,

Amy Martin: 00:28:03

2000 you'd be going out recording with, say, your hand

Amy Martin: 00:28:07

held recorder and a DAT tape, and recording for one or two

Amy Martin: 00:28:12

hours. And now you can find a recorder that will go out, you

Amy Martin: 00:28:16

can deploy it, and it can record for six months or so, even a

Amy Martin: 00:28:20

year and pick up a wealth of data, and it may be a quarter of

Amy Martin: 00:28:23

the price.

Amy Martin: 00:28:24

The quality the audio we're able to record has

Amy Martin: 00:28:27

also grown exponentially, so we can now record in more places

Amy Martin: 00:28:31

for longer periods of time in much higher fidelity than ever

Amy Martin: 00:28:35

before. And that means it's possible to conceive of a day

Amy Martin: 00:28:39

when we have good recordings of all the fish on earth.

Amy Martin: 00:28:42

Dr. Miles Parsons: Now that's going to take a while.

Amy Martin: 00:28:44

Again, scientists have so far documented that

Amy Martin: 00:28:47

about a thousand fish species make sound out of around just

Amy Martin: 00:28:51

1200 studied.

Amy Martin: 00:28:52

Dr. Miles Parsons: We expect somewhere between 15 and 25,000

Amy Martin: 00:28:57

species of fish produce sound of some kind. So we got a long way

Amy Martin: 00:29:01

to go.

Amy Martin: 00:29:03

But recording all of this sound is one thing, using

Amy Martin: 00:29:06

it is another. In just 30 minutes, I captured quite a few

Amy Martin: 00:29:10

sounds in that Swedish lake. If I were a scientist, each of

Amy Martin: 00:29:14

those sounds would need to be identified, labeled, organized,

Amy Martin: 00:29:18

stored. And 30 minutes is nothing really. What if I had 30

Amy Martin: 00:29:24

hours of recordings or 3000? It wouldn't take long for me to

Amy Martin: 00:29:28

record more acoustic data than I could ever listen to. This is

Amy Martin: 00:29:33

the situation that a lot of bioacoustics researchers are in

Amy Martin: 00:29:37

right now. The rate at which we're able to acquire data has

Amy Martin: 00:29:41

far outpaced the rate at which we can process it.

Amy Martin: 00:29:44

Dr. Miles Parsons: We're moving into an era where artificial

Amy Martin: 00:29:45

intelligence can start to analyze these huge volumes of

Amy Martin: 00:29:49

data that we're collecting.

Amy Martin: 00:29:51

Scientists are already using AI to search

Amy Martin: 00:29:54

through thousands of hours of recordings at lightning speed

Amy Martin: 00:29:57

and say, here are all the sounds that seem to be alike.

Amy Martin: 00:30:01

Dr. Miles Parsons: And then we can build up these data sets

Amy Martin: 00:30:03

that AI algorithms can then search for in other recordings,

Amy Martin: 00:30:08

but that will take time.

Amy Martin: 00:30:11

Later this season, we'll learn about efforts to use

Amy Martin: 00:30:13

AI to actually decode what other animals are saying, kind of like

Amy Martin: 00:30:18

the universal translator in Star Trek, but for dogs or dolphins.

Amy Martin: 00:30:23

But we can't translate a voice we've never heard or never paid

Amy Martin: 00:30:27

attention to. Someone still needs to do the foundational

Amy Martin: 00:30:31

work of pairing the singers with the song. That's why researchers

Amy Martin: 00:30:36

like Lauren Hawkins are manually listening through hour upon hour

Amy Martin: 00:30:41

of recordings, making notes, talking to other researchers,

Amy Martin: 00:30:45

helping to assemble an accurate reference catalog of sounds.

Lauren Hawkins: 00:30:49

Like I'm at the real basic stages of just being

Lauren Hawkins: 00:30:52

like, that's a fish chorus that that was found there, these are

Lauren Hawkins: 00:30:55

the parameters of what it looks like, and this is what it does.

Lauren Hawkins: 00:30:59

Okay, that's one. And then the next and then the next one and

Lauren Hawkins: 00:31:02

the next one and the next one. But that's a really good

Lauren Hawkins: 00:31:05

foundation for someone to then go in and go, well, how does

Lauren Hawkins: 00:31:08

this fish course change over time?

Amy Martin: 00:31:12

Then we can ask questions about things like

Amy Martin: 00:31:15

population size and health, changes in ocean currents, the

Amy Martin: 00:31:19

status of associated predators and prey, including the highest

Amy Martin: 00:31:24

impact predator in the sea, us. Overfishing is the biggest

Amy Martin: 00:31:29

global threat these animals face. Simply put, we're pulling

Amy Martin: 00:31:34

fish out of the water much faster than they can reproduce.

Amy Martin: 00:31:38

It's an unsustainable level of consumption with a host of

Amy Martin: 00:31:41

complex factors at play, from illegal fishing to harmful

Amy Martin: 00:31:45

fishing practices, wasteful bycatch and more, and that's

Amy Martin: 00:31:50

before we even get into climate, pollution and other impacts.

Amy Martin: 00:31:54

Lauren says all of this brings real urgency to her work.

Lauren Hawkins: 00:31:58

So by the time we get our hydrophones out, you

Lauren Hawkins: 00:32:01

know, what used to be there might not be there anymore. So

Lauren Hawkins: 00:32:04

it's really important that that we we start getting those

Lauren Hawkins: 00:32:07

baselines, but then we also use that to inform how we need to

Lauren Hawkins: 00:32:10

monitor into the future.

Amy Martin: 00:32:13

It's not all about tracking problems. She says it's

Amy Martin: 00:32:16

also about measuring success. If we try out a new management

Amy Martin: 00:32:20

strategy in the effort to bring a species back from decline, and

Amy Martin: 00:32:24

it works, then we need to know that.

Lauren Hawkins: 00:32:27

We've got to have some way to measure it. You

Lauren Hawkins: 00:32:30

don't know you've won unless you've got a score. And using

Lauren Hawkins: 00:32:34

acoustics and using fish is a way of scoring it.

Amy Martin: 00:32:37

So fish sounds can be put to use in very concrete,

Amy Martin: 00:32:41

specific projects, but they can also be part of the larger quest

Amy Martin: 00:32:46

of our era, bringing ourselves into better relationship with

Amy Martin: 00:32:50

our planet mates. As mammals, we tend to bond most deeply with

Amy Martin: 00:32:57

other mammals, even species that look really different from us,

Amy Martin: 00:33:01

like whales or elephants, form relationships that we recognize

Amy Martin: 00:33:06

and can relate to.

Lauren Hawkins: 00:33:07

So, you already have that sort of emotional

Lauren Hawkins: 00:33:10

connection, and you can empathize with the plight of

Lauren Hawkins: 00:33:12

these animals.

Amy Martin: 00:33:14

Fish are different, and often we tend to turn away

Amy Martin: 00:33:18

from difference, to recoil from it or fill the gap with

Amy Martin: 00:33:22

assumptions and fictions. We tell ourselves that fish are

Amy Martin: 00:33:26

stupid or that they don't feel pain. But Lauren says it's not

Amy Martin: 00:33:32

so easy to disregard fish when you listen to them.

Lauren Hawkins: 00:33:38

These animals are, they are communicating.

Lauren Hawkins: 00:33:41

They are animals. They have a life. You know, if they're

Lauren Hawkins: 00:33:46

animals that can talk to each other during their daily lives,

Lauren Hawkins: 00:33:50

they're communicating. There is intelligence there.

Amy Martin: 00:33:56

Maybe fish pose a special challenge to our

Amy Martin: 00:33:58

intelligence. Are we smart enough to drop our

Amy Martin: 00:34:02

preconceptions and comprehend the sounds they make on their

Amy Martin: 00:34:05

own terms? Lauren's hopeful that bioacoustics can be more than a

Amy Martin: 00:34:13

scientific tool, that it can open people up to the wonder of

Amy Martin: 00:34:17

the conversations happening around us all the time. Not only

Amy Martin: 00:34:21

among fish, but all kinds of creatures.

Lauren Hawkins: 00:34:24

Oh, I love it. I love I love the research that I

Lauren Hawkins: 00:34:27

do. I could easily do it for the rest of my life. I never lose

Lauren Hawkins: 00:34:33

that sense of like, how lucky I am to be able to listening in

Lauren Hawkins: 00:34:38

and to hear things that people don't hear and people don't

Lauren Hawkins: 00:34:41

know. Like, there's recording locations close to shore, which

Lauren Hawkins: 00:34:44

people use very regularly, and I'm like, you would have no idea

Lauren Hawkins: 00:34:48

that underneath the surface there's a blue whale going past,

Lauren Hawkins: 00:34:52

and there's, you know, fin whales, and there's humpback

Lauren Hawkins: 00:34:55

whales, you know, screaming around.

Amy Martin: 00:35:00

And these fish choruses.

Lauren Hawkins: 00:35:02

And these fish chrouses. Yeah, these guys are

Lauren Hawkins: 00:35:03

calling, and all this life is happening that, yeah, if you

Lauren Hawkins: 00:35:08

didn't pop your, your head down in the water, you wouldn't, you

Lauren Hawkins: 00:35:11

wouldn't know.

Lauren Hawkins: 00:35:20

Dr. Miles Parsons: There are an amazing variety of different

Lauren Hawkins: 00:35:24

sounds that are absolutely fantastic. I've played piano

Lauren Hawkins: 00:35:27

from like four years old, so have a strong connection to

Lauren Hawkins: 00:35:31

music. And as far as I'm concerned, the fish noises and

Lauren Hawkins: 00:35:34

the marine noises and soundscape is all a form of music.

Amy Martin: 00:35:44

There are few things more comforting than

Amy Martin: 00:35:47

understanding another person and feeling understood. We can pick

Amy Martin: 00:35:52

familiar voices out of a crowd. We're hardwired to pay attention

Amy Martin: 00:35:56

to communication from those we know and love, but talking to

Amy Martin: 00:36:00

Lauren and Miles and feeling their excitement about tuning

Amy Martin: 00:36:04

into creatures who communicate so differently from us, makes me

Amy Martin: 00:36:08

wonder if we're also hardwired for listening across huge

Amy Martin: 00:36:12

divides. Yes, we humans can be close minded and arrogant and

Amy Martin: 00:36:19

fearful of the unknown, but we can also find connection and

Amy Martin: 00:36:23

sheer delight in the mystery of the unks and boops and kwas.

Amy Martin: 00:36:39

This episode of Threshold was written, recorded and produced

Amy Martin: 00:36:43

by me, Amy Martin, with help from Erika Janik and Sam Moore.

Amy Martin: 00:36:47

Music by Todd Sickafoose. Post-production by Alan Douches.

Amy Martin: 00:36:52

Fact checking by Sam Moore. Special thanks to Lauren

Amy Martin: 00:36:56

Hawkins, Miles Parsons and Tim Lamont for many of the fish

Amy Martin: 00:37:00

recordings you heard in this episode. Clara Amorim and Raquel

Amy Martin: 00:37:04

Vasconcelos recorded that Lusitanian toadfish. Herbert

Amy Martin: 00:37:08

Tiepelt recorded the pikeperch percussionist and Marta Bolgan

Amy Martin: 00:37:12

provided the "unknown kwa" I love so much. Additional

Amy Martin: 00:37:17

recordings came from more than a dozen other scientists, many of

Amy Martin: 00:37:21

whom have contributed sounds to the website fishsounds.net.

Amy Martin: 00:37:25

Check the show notes or our website for links to many of

Amy Martin: 00:37:28

these sounds and the scientists who recorded them. This show is

Amy Martin: 00:37:32

made by Auricle Productions, a nonprofit organization powered

Amy Martin: 00:37:36

by listener donations. Deneen Weiske is our Executive

Amy Martin: 00:37:40

Director. You can find out more about our show at threshold

Amy Martin: 00:37:43

podcast.org.