0:04

Listen to supported WNYC

0:06

studios. Hey,

0:09

it's Latif from Radiolab. Our goal

0:11

with each episode is to make

0:13

you think, how did I live

0:15

this long and not know that?

0:18

Radiolab adventures on the edge of what

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we think we know. Listen, wherever you

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get podcasts. Just

0:27

below the surface, the ocean is

0:29

bursting with sound. Wow,

0:32

there's this whole thing going on

0:34

underwater. These fish are meeting and

0:36

they're humming and I

0:38

would never know. You would never know. It's

0:41

Thursday, June 13th and you're listening

0:43

to Science Friday. We sci-fi producer

0:46

Shoshana Buxbaum. I've always thought

0:48

about the ocean as a quiet and

0:50

serene place. Take a dip underwater and

0:52

the sounds above you just melt away.

0:55

But in reality, the ocean is

0:57

quite a noisy place. Think whale

0:59

songs or echolocation, which whales

1:02

and dolphins use to communicate. Cephalopods

1:04

can make and hear sounds too,

1:06

even without ears. And

1:08

then there's the human made noise like the

1:10

giant shipping containers that crisscross the

1:13

globe. Here's Ira with more.

1:16

Joining me is Amarena Kingdon, science

1:19

journalist and author of the

1:21

book, Sing Like Fish, How

1:23

Sound Rules Life Underwater. She's

1:25

in Victoria, British Columbia. Welcome

1:27

to Science Friday. Thank

1:29

you so much. I'm so eager to

1:31

talk about this because as somebody who considers himself

1:34

close enough to a fish, I

1:36

love the water. I'm a scuba diver. And

1:38

I want to know what inspired you to write this

1:40

book. Well,

1:44

I, like most humans, kind of

1:46

thought that the ocean and underwater

1:48

was a silent world. And,

1:50

you know, when I was a kid, I remember

1:52

swimming and putting my head underwater and kind of

1:54

thinking that sound didn't really work there. And

1:57

then I was working on a story. for

2:00

Hakai magazine here in Victoria. And

2:03

it was about the relationship between

2:05

cleaner wrasse and their client fish. And

2:07

so cleaner wrasse are these little tiny

2:10

fish that live on various

2:12

reefs. And they set up these stations

2:14

where they clean larger fish and they bite

2:16

parasites off of them. And in

2:18

exchange, the larger fish doesn't eat them. It's kind

2:20

of a symbiotic relationship. And the

2:23

study found that when there was motorboat

2:25

noise around that that whole relationship dynamic

2:27

kind of changed. Like the cleaner wrasse

2:30

would try to take more bites

2:32

or they cheat more often. And the rate

2:34

at which the bigger fish caught them would

2:36

change. And I just kind of had

2:38

this moment where I realized that, you

2:41

know, sound and noise, it doesn't just

2:43

affect obvious things like hurting your ears

2:45

or something like that. It can change

2:47

the minutiae of like the behavior of animals.

2:50

And then I started to think, okay, now

2:52

I start to see how sound can impact

2:54

all these different like facets of

2:57

life underwater. So then I started really digging in.

3:00

So where did this idea of the ocean

3:02

being a quiet place come from?

3:04

Is it just that humans are not good at

3:06

hearing sounds underwater? I mean, if you put your

3:08

head underwater in the ocean, you really don't hear

3:10

much. Yeah, I mean, I

3:12

think that's a part of it. Even

3:14

if you stick your head underwater in

3:16

the bathtub to rinse shampoo when you're

3:18

a kid, like most people have some

3:20

moment where they just kind of think,

3:22

oh, there's nothing here. There's nothing to

3:24

sense. And actually for like decades of

3:26

scientific exploration until fairly recently, people

3:29

even specifically studying sound underwater would just put

3:31

their head underwater. And if they didn't hear

3:33

much, then they would just assume that there

3:35

wasn't much to hear. But actually

3:38

a lot of the scientists I spoke to

3:40

recently have said that, you know, the trope

3:42

of the silent world kind of came about

3:44

when Jacques Cousteau in the 1950s did

3:46

his very famous film about all the animals

3:49

in the ocean, the coral, and

3:51

it was called The Silent World. And

3:53

so I think that image just kind of stuck. So

3:57

how does sound move differently? Underwater

4:00

versus on land. I know there's a

4:02

different density water and air right to

4:05

make a long story short Sound is a pressure

4:07

wave and it can move through anything that compresses

4:09

even a little bit and like you said water

4:11

is a lot denser Than air and

4:13

sound actually moves pretty easily through water like

4:15

almost more easily than air and it moves

4:17

four and a half times faster So

4:20

in air, it's about about three hundred

4:22

and thirty meters per second in water.

4:24

It's about fifteen hundred meters per second

4:27

Wow, and the other thing that happens

4:29

underwater is that sound loses energy less

4:31

quickly so it travels a lot farther

4:33

a lot faster and when it gets

4:36

there it's For

4:38

lack of a better word kind of decayed or distorted

4:40

maybe a little bit less than it would in here

4:43

Mm-hmm. You're right about the

4:45

plainfin mid shipment a Very

4:48

strange looking fish with

4:50

a strange way of producing very loud

4:52

sound So let's play for our audience

4:54

what that fish sounds like I

5:00

thought that was a ship horn I've

5:03

heard I've heard a ship horn Like

5:05

yes, it's almost mechanical sounding isn't it?

5:08

Yeah, it is, but it's not Nope,

5:11

it's um, it's extremely extremely fast

5:13

muscles and that that's the male

5:15

and he's got these really really

5:17

bulked up Massive muscles right alongside

5:19

his swim bladder, which is sort

5:21

of an air-filled Bladder

5:23

in his body that normally a fish

5:25

uses to control his buoyancy and

5:27

he's vibrating that muscle like really really really hard

5:29

against that swim bladder and just making that hum

5:32

and He's actually

5:34

doing that like almost onshore So plainfin

5:36

midshipman will in the spring they'll come

5:38

up the males will come up and

5:41

they'll make a nest Right

5:43

at the tide line sometimes when the tides low

5:45

They'll actually be out of the water and they'll

5:47

go under a rock and they'll sit in a

5:49

little pool and they will Make

5:51

this hum they will make this really really

5:54

loud very

5:56

droning Perhaps not immediately

5:58

interesting sounding to us hum and what

6:00

it does is it travels out into

6:02

the water and It

6:04

reaches female midshipmen who are kind of

6:06

out out in the more open water

6:08

and they hear that sound and

6:11

in the spring their ears actually become more

6:13

sensitive to the frequencies in that hum and

6:15

so they hear this sound and they go

6:17

and they find the male with the loudest

6:19

hum the biggest muscles the

6:22

Presumably the best ability to guard the eggs and

6:24

they go and try to find him and

6:27

you went along with some researchers Studying them right?

6:29

What was that like? Well, I

6:31

found that the plainfin midshipmen when you

6:34

meet it face to face is a

6:36

very funny looking fish It's actually it's

6:38

very slimy. It doesn't have scales It's

6:40

skin is very smooth and it has

6:43

this really big triangular head and they

6:45

do not they do not look particularly

6:48

impressive especially not during the daytime or in

6:50

the morning, but And

6:52

I actually went to quite a

6:54

few different places around southern Vancouver Island Trying to

6:57

trying to listen to them trying to find them

6:59

I had a little dip hydrophone that I bought

7:01

when I started working on this project and everywhere

7:03

I went whenever I was on the coast. I

7:05

just put it in the water and see what

7:08

I could hear Cool. I

7:10

was trying to find this fish for

7:12

for years and I couldn't quite find

7:14

it where they were they were going and

7:16

then It was

7:18

actually just last year. It was a spring night

7:20

I had actually got a broom handle to help

7:22

fish the cord of the hydrophone off the dock

7:24

and I managed to get it into the Water

7:26

and as soon as it plunked into the water,

7:29

I could hear this hump It was

7:31

it was really loud in my headphones and as

7:33

soon as I pulled the hydrophone back out of

7:35

the water It vanished I couldn't

7:37

hear it above the water at all and

7:39

I was looking around and there was sailboats

7:41

moored And there was a you know us

7:43

little town over there and some condos and

7:46

I was just thinking wow There's this whole

7:48

thing going on underwater. These Fisher are

7:50

mating and they're they're finding each other

7:52

and they're humming And I would

7:55

never know you would never know if we

7:57

hadn't gone out with a broom handle and

7:59

dip this hydrophonic water. Let's

8:01

talk a bit about something really fascinating

8:03

too. And that's how

8:06

invertebrates perceive sound underwater, yet

8:09

they don't have ears. Yes.

8:12

And this was one of the most

8:14

mind blowing things that I learned. And

8:16

there's a structure that evolved really, really

8:19

early in the history of animals that

8:21

actually evolved underwater back

8:23

before animals even had bones.

8:26

And it's a hair cell. And essentially,

8:28

that is at its simplest

8:30

description, a cell that has a little

8:32

protrusion on it called a hair. And

8:35

when that hair bends, or is bent

8:37

by something, it fires a

8:39

signal into an attached neuron. And

8:41

so that is the basis. It's

8:44

kind of like a transducer, it transduces a

8:46

mechanical force into an electric

8:48

signal. If you remember, sound

8:50

is a pressure wave. And so it's actually moving the

8:53

molecules. So whenever you have a hair

8:55

cell, you have at least the potential for

8:57

detecting a sound. And so

9:00

in animals like squid, or a lot

9:02

of other invertebrates that evolved pretty early,

9:04

they don't have ears and ear being

9:07

a structure that's specifically designed to

9:09

hear sound. But what they

9:11

do have are balance organs, for example,

9:14

which are called in some animals, a

9:16

statusist. And to take for

9:18

an example, a statusist, it's basically a chamber

9:20

lined with hair cells, and there's a little

9:23

stone or a thing of sand in the

9:25

middle. And as the animal kind of

9:27

moves through the water, pitches, yaws, turns

9:29

right, left, up, down, the

9:31

mass and the inertia of the mass will

9:33

move against the hair cells and it'll tell

9:35

the animal what direction it's

9:37

oriented. And that structure

9:40

seems to be able to also perceive

9:42

low loud sounds. And it seems to be

9:44

the case, at least with squid

9:46

or other shellfish. And these hair

9:49

cells are not just in statusists,

9:51

they can be in organs and

9:53

shellfish called abdominal sense organs, they

9:55

can be in crustacean antenna, tons

9:59

of different structures. that aren't purpose-built

10:01

for hearing sound or detecting sound,

10:03

but they can still tap into

10:05

that stimulus wherever it's in the

10:07

water. Wow. You

10:10

start off the book shadowing researchers who

10:12

were studying kelp forests. I'm particularly fond

10:14

of kelp forests because we're growing kelp

10:16

right here in Long Island Sound where

10:18

I live. What a

10:21

fascinating way to start the book.

10:23

How does kelp affect how sound

10:25

travels underwater? Well,

10:27

that's actually exactly what they were trying

10:29

to research. The thing

10:31

that I thought was fascinating about that study, obviously

10:33

we have a lot of kelp here too on

10:36

the west coast all up and down, is

10:38

that those scientists by their

10:40

own admission, they're not

10:42

sound scientists. They're not acousticians. They're

10:45

not physicists. They're community ecologists and

10:47

biologists who are studying the kelp

10:50

ecosystem as a whole. They're looking

10:52

at how it may change

10:54

in the future because kelp doesn't really like

10:56

warm water. If there's warming from climate change,

10:59

it's going to diminish. There's

11:01

tons of baby animals that live in

11:03

kelp. Kelp's a nursery. It's a refuge.

11:05

It's food. It's a really

11:07

critical ecosystem in the ocean. What

11:10

I thought was fascinating was that people

11:12

who don't study sound are now

11:15

including sound as just a

11:17

basic parameter of marine ecosystems that should

11:19

be studied because we're starting to realize

11:22

more so than ever before just

11:24

how central sound is underwater. Like

11:27

when I dove into that kelp forest, we saw

11:29

urchins and we saw fish and we

11:31

saw invertebrates and we saw nudibranchs and

11:33

all of these animals could

11:36

detect the sound of my swimming

11:38

even though none of them had

11:41

necessarily what we

11:43

would recognize as like an ear or a human

11:45

ear. Aside from the sea

11:48

life that lives there, the ocean makes

11:50

its own sounds, right? Oh yes,

11:53

yes. The ocean is not a quiet place at

11:55

all. It's very

11:57

– even before animals, the wind and waves

11:59

– waves make sounds. There's bubbles that

12:01

form at wave crests and they pop.

12:03

They oscillate and make a sound and

12:06

then ice makes a sound. So in

12:08

the Arctic regions, you have cracking and

12:10

booming and melting and ice quakes. And

12:12

then icebergs can drag along the

12:14

sea floor and they make sounds as they

12:17

melt. And there's

12:19

also mudslides, there's earthquakes.

12:21

The, like an earthquake can

12:23

often be picked up hundreds and hundreds of

12:26

kilometers away. How about rain? Rain

12:28

makes a sound. Yeah. And you can

12:31

actually tell, if you listen very carefully

12:33

with the right instruments, you can tell

12:35

the drop size from the sound underwater.

12:37

You can track storms. Even snow makes

12:40

a sound. I thought this was beautiful.

12:42

Snow makes a sound. Snow makes a

12:44

sound. A snowflake falling on water creates a kind

12:46

of a double sound. It's like a

12:48

plink when it falls. And then as it melts

12:51

underwater, it creates this kind of high

12:53

shrieking hiss noise. And it's very, very subtle.

12:55

But yeah, and this was actually discovered completely

12:57

randomly about 100 kilometers north of me on

13:00

a lake in 1985. One of the researchers

13:04

was listening to rain and it turned

13:06

into snow and he just kept recording

13:08

and discovered the sound that snow makes.

13:10

So the ocean is absolutely full of

13:12

noise. A journalist gives up his

13:14

disinformation beat to buy a site

13:16

of satirical fake news. The

13:18

Onion. We often hear from journalists that

13:21

running a media outlet shouldn't be complicated

13:23

and yet the suits make it so.

13:25

You're now a suit, Ben. Yeah,

13:28

that's right. Is

13:30

it complicated? You can't say this,

13:32

but I'm in two tuxedos right now. It's one tuxedo

13:34

inside of another tuxedo. On this week's On

13:36

the Media from WNYC, find

13:39

on the media wherever you get your

13:41

podcasts. And if

13:43

we make some of that noise, we humans, don't

13:45

we? Yes, we do. Some

13:47

loud, some soft, but yes, a lot of it.

13:50

And are the animals aware of this? Oh,

13:52

yes, yes. Now, it does depend on

13:55

the animals hearing range, the frequencies that they hear at.

13:57

But humans. make

14:00

noise, all different kinds of

14:02

noise. Broadly speaking, you could classify it

14:04

into sort of two camps. They're sort

14:06

of very loud, very impulsive

14:08

noises that tend to come from

14:10

things like pile driving or close

14:12

up to air guns or things

14:15

like that. And then you

14:17

get kind of this more chronic droning

14:20

noise that comes from ships and shipping

14:22

lanes. And that

14:24

second one has pervaded pretty much the entire

14:27

ocean. You can hear ships at the bottom

14:29

of the Mariana Trench. You can hear ships

14:32

basically everywhere in the ocean. The amount

14:34

of shipping in the world has really

14:37

risen recently. I believe that

14:39

the energy from shipping

14:41

noise in the ocean actually doubled each decade from about

14:43

the 1960s to about the 2010s. And that's

14:47

doubled each decade. How can scientists

14:49

then study how these loud

14:51

human-made noises are affecting marine

14:53

life? Well, we've

14:55

done a lot of the first initial studies

14:57

were on marine mammals because a lot of

14:59

that was a little bit more obvious to

15:01

study. So they have some tags that you

15:03

can put on a whale that stick on

15:06

with the suction cup and they can follow

15:08

a whale and study how it reacts to

15:10

sound, how it responds, does it run away?

15:12

Does it make sounds? Does it make sounds

15:14

differently? And so a lot of that has

15:16

helped start the process

15:18

of figuring out how we affect these animals.

15:20

But there's also a lot

15:22

of animals that we just haven't even thought to

15:25

study, like the fish and the invertebrates that we

15:27

thought didn't really care about sound until recently. It's

15:30

really difficult to study how they respond

15:32

to sound because we can't directly interview

15:34

them. And sometimes the effects are not

15:36

quite very obvious. So one

15:39

of the sort of unfortunate things about our

15:41

studies of impacts of things on animals is

15:43

that we tend to say, Oh, is

15:46

the animal still alive? Is it visibly

15:48

hurt? No, well, then it's probably fine.

15:51

But if you think about all the different ways that

15:53

sound can work with these animals'

15:55

lives, finding mates, finding food,

15:58

navigating, staying in touch each

16:00

other. If sound impacts those

16:02

things, you can, it's like

16:04

with the cleaner wrasse or the larger fish,

16:06

it's not an obvious impact, but it can

16:08

really ripple down through how it lives its

16:10

life and whether or not it has offspring,

16:12

whether or not it survives. So

16:15

we're just starting to understand how

16:17

invertebrates perceive sound and what matters

16:19

to them, let alone how human

16:21

noise affects them. So we

16:24

need to know more about how

16:26

they perceive sound before we start

16:28

talking about how we reduce our

16:30

own sound in the ocean. I

16:32

mean, should we be making boats quieter, things

16:34

like that? We definitely need

16:36

to know more about how these animals

16:38

perceive sound. And we're even discovering that

16:40

on the seafloor, there may

16:43

be animals that can tap into vibrations

16:45

the same way that they tap into

16:47

sound. I mean, we're just starting to

16:49

really look at this kind of thing.

16:51

There are actually some regulations that are

16:53

starting to be discussed right now. The

16:56

IMO is discussing underwater

16:58

sound. The International Organization

17:01

for Standardization, ISO, is

17:03

actually starting to put research into how

17:05

exactly you should measure a ship sound.

17:08

And that's actually a weird question. You would think,

17:10

oh, you just put a hydrophone in the water

17:12

and measure how loud a ship is. But it

17:14

turns out it's actually really complicated. So

17:16

something that big, most of the sound

17:18

comes from its propeller, and the sound

17:20

moves and spreads through the water totally

17:22

differently, whether the ship is high in

17:24

the water, low in the water, if

17:27

it's in deep water, if it's in

17:29

shallow water. So even just measuring a

17:31

ship noise, let alone how it affects

17:33

anything else, turns out to be this

17:35

really complex mathematical problem. And so we're

17:37

just studying that now to try to

17:40

figure out how we can fix that.

17:42

But there's also efforts to

17:44

engineer quieter ships. Naval architects are

17:46

figuring out how they can make different propellers,

17:48

different bow shapes that might reduce wash on

17:51

the hull, all that kind of stuff. We

17:53

could go on forever because I'm a water person like

17:55

you are. So well, we've run

17:57

out of time. This is such a great book,

17:59

Amareta. Thank you for taking time to be with

18:01

us today. Thank you so much. I'm

18:04

Marina Kingdon, science journalist and author of

18:06

the book, Sing Like Fish, How Sound

18:09

Rules Life Underwater. She's based

18:11

in Victoria, British Columbia. Of course,

18:13

that's in Canada. If you

18:15

want to read an excerpt of the

18:17

book, go to sciencefriday.com/likefish. That's

18:21

sciencefriday.com/likefish. That's

18:23

it for today. Lots of folks helped make the

18:26

show happen, including Jason

18:28

Rosenberg, George Harper, Kathleen

18:30

Davis. Tomorrow, a roundup of

18:32

the top science stories of the week. I'm

18:35

sci-fi producer Shoshana Buxbaum. Catch

18:37

you next time.