Jack Pearson talks to Amorina Kingdon about her new book, Sing Like Fish, which breaks misconceptions about the “silent world” of water – and why your next bit of swim kit might be a hydrophone.
I grew up in Ontario, and I grew up on a lake. So I spent my life swimming, like I knew how to swim before I knew how to probably talk. Ever since I moved out to BC [British Columbia] the ocean obviously is a little bit colder, so it’s not quite as easy to just jump in. But in the last couple of years, some friends and I have formed what we affectionately refer to as the Great Lakes Swimmer Society. And here in Victoria there’s quite a lot of little lakes and little ponds and stuff. And we also find, you know, beaches or inlets or rivers, where we can swim in the summer. So yes, I am an avid swimmer.
Well, for a very long time I didn’t really think about it at all. I always found that it was extremely peaceful underwater, if I held my breath and went underwater and just sat there. It was this profoundly peaceful moment, partly because you could almost hear nothing. There were motorboats on the lake that I grew up on. If you were above the water, you’d see a boat going by and the motor in the air would make this noise. Then you’d put your head underwater, and it would be quieter. It just drove home this idea that sound didn’t work underwater, like there wasn’t anything there. And so I think for me, it was this weird sensory deprivation thing that I found very beautiful. So to discover that that was because my ears weren’t supposed to work there, and not because there was nothing there to hear was like another level of wonder. But before that, it was the wonder of silence and the wonder of peace, if that makes any sense.
I was assigned a story about the cleaner wrasse fish. This fish sets up a symbiotic relationship where it sits on a spot on the reef, and a bigger fish come by, and the wrasse will eat parasites off the bigger fish. So it gets a meal and, in exchange, it doesn’t get eaten. If you watch them for a while, the cleaner wrasse will, when it thinks the bigger fish might be distracted, take a scale off the fish because the scale is bigger and juicier than a parasite. But if the big fish notices, it chases the cleaner wrasse. Researchers found that when there was motorboat noise around the wrasse would try to take bites of the bigger fish, more often, and it seemed like [the larger fish] were more distracted because they didn’t chase them quite as much. The dynamic changed.
It just really made it clear to me that we can have impacts on animals that we don’t immediately notice, but that can really affect their day-to-day life in ways that can compound over months and months. Then I got the chance to go on a reporting trip up to Cook Inlet in Alaska to look at beluga whales. And I remember sitting there on the ocean and hearing this whole pot of beluga whales that come up and make sounds above the water – then put a hydrophone in the water, and you could hear a whole other set of sounds below the water. Until I reported on those two stories, I had this cognitive gap in my head between sound and underwater, because I’m a human and I just didn’t think it was a thing. So I got really interested in trying to just understand that gap.
I wonder what other animals are perceiving when I move past them, for sure. I wonder, can they hear my heartbeat? They can definitely hear the splashes. I wonder if I’m scaring them. I wonder if I look like a predator to them, or sound like a predator to them.
It was a slow thing. But the belugas were really fascinating precisely because the water in Cook Inlet is opaque, like chocolate milk. It’s very silty. It drove home really viscerally and visually–because humans are more visual than audio in a lot of ways–that there is no way these animals could keep in touch with each other without sound. [On the boat] we couldn’t see the whales, but we could feel them bump the boat. We didn’t want to keep the depth finder on too much, because it uses little pings of sound, and we didn’t want to bother the whales. But we did turn it on every once in a while, just to make sure we weren’t going to strand in the mud. On the depth finder we could see the shape of a beluga drifting under the boat and you could see this little shape under it. The scientist that I was with said, “Oh, that’s a that’s a mom, and its calf.” If they get separated they can be stranded on these mud flats. The only way they have to keep in touch with each other is sound.
When I started working on the book, I bought a little dip hydrophone. I could go out to paddleboard and canoe and every time I put it in the water, I would just hear so much that I could never hear on my own: fish and crabs and invertebrates and waves. You put it in on a dock, and you can hear the ores off the side of a sailboat across the strait. Every time I did, it was like a whole new world.
I wonder what other animals are perceiving when I move past them, for sure. I wonder, can they hear my heartbeat? They can definitely hear the splashes. I wonder if I’m scaring them. I wonder if I look like a predator to them, or sound like a predator to them. Also, a whole bunch of other animals underwater perceive sound with something other than an ear. Crustaceans have organs in their joints that can detect sound. So, I wonder if they’re perceiving me as a sound, or if I feel like a vibration to them.
And then I wonder what it is that I’m not able to tap into that’s going on around me. If I’m in the ocean, I wonder whether there is ship and boat noise that I can’t hear? Or, if I’m in a lake, I wonder if there are insects chewing. So, when I don’t have a hydrophone and I’m just swimming, I feel like I’m on the other side of a piece of glass. Just like, Oh, I wish I could be in there with the cool kids.
If I’m in the ocean, I wonder whether there is ship and boat noise that I can’t hear? Or, if I’m in a lake, I wonder if there are insects chewing. When I don’t have a hydrophone and I’m just swimming, I feel like I’m on the other side of a piece of glass. Just like, ‘Oh, I wish I could be in there with the cool kids’.
Cristian Palmer via Unsplash
Oh, I know. You think about how 90% of the species in the ocean are invertebrates that don’t have an ear, but they’re still perceiving sound somehow. And you just think to yourself, we have no idea what it’s like to be these other animals, at least acoustically. Touch at a distance is not my term, it’s from a paper that came out decades ago. But it is functionally touch at a distance: an animal has a set number of senses that help it figure out what’s going on in its environment and the only difference between sound and touch is distance, and a wave is energy moving through a medium from one place to another. So, it’s basically bringing that touch to you.
I was seeing that there were more and more articles coming out in the mainstream media about sound pollution underwater. And I found, personally, that when I would read these stories about sound underwater and noise pollution underwater, there was that conceptual gap in my head. Because I can’t perceive sound underwater the way that a marine animal does, I just don’t totally understand what it means. If somebody publishes a story about an oil spill and gives me a picture of a bird soaked in oil. It’s pretty clear to me, that’s a problem, right? But when people would talk about noise pollution I couldn’t quite picture it, I couldn’t quite understand it, I couldn’t relate to it.
Though I didn’t want to write a book that was focusing on those negatives alone. I wanted to write a book that would explain as much as I thought I could about why sound underwater is so important to animals, so that people would be amazed. Because it’s just really cool. I hope that people who read the book will have a deeper understanding. And then if they learn about a shipping lane causing problems for right whales, or why we should map the soundscape of deep-sea mining efforts, then they’ll have that extra level of connecting the dots, of why that’s important.
I think one of the coolest things you could do is, if you’re swimming in the wild, figure out what fish are in your favorite swimming spot, and look them up on a website of fish sounds. See whether or not they make sound, and if so, when and where and why. Hydrophones are weird to try to come by. It may not be feasible for everybody to just go out and buy one. They are minimum $200, but if you are part of a group, I think it’d just be fun to pool your funds and get one. And just go out and listen, every once in a while, and listen to different times of day and times of year, because a lot of animals only make sounds in particular circumstances.
Here in BC, there’s a fish called the plainfin midshipman. And it only sings between 10 and midnight, between April and June. And other than that, you won’t hear it. I spent like, two years trying to listen to this fish. And I was, like, creeping around on coasts, like with this hydrophone. Like, come on, where are they? And like, finally I heard them last year. I find it really amazing to just put some headphones on, if you do have access to a hydrophone, and just listen to the soundscape of the water. It’s the space, the acoustic space, of that water, and you hear like little crunches and ripples. And it just makes you more aware that it’s a living ecosystem that is, you know, doing its thing.
…if you are part of a group, I think it’d just be fun to pool your funds and get [a hydrophone]. And just go out and listen, every once in a while, and listen to different times of day and times of year, because a lot of animals only make sounds in particular circumstances.
Oh, totally, totally. Like fish sound listening! That’d be amazing. You’re in a river or a lake that has anything with the catfish family, that’s always interesting. A lot of soniferous species are catfish. And if you’re in a river or a lake that has deep water and marsh or weed beds or something they’ll have different soundscapes. Weed beds often are home to a lot of insect larvae which will chew and eat the weeds. Even if you can’t listen in, you can be aware of it. Usually, a sheltered, weedy place is like a nursery for larvae and baby fish. And they’re usually like eating and chewing and making a certain amount of noise.
I wanted to illustrate why we started to look deeper. It’s all fascinating, the fact that we even started listening underwater and how much it was driven by Victorian gentleman scientists trying to figure out the speed of sound and then the massive influence of wars and submarines, and how that kind of drove this weird arms race to listen for the enemy. I was struck by how often we rediscovered the same sorts of things, like Aristotle thought that fish made sounds and had voices.
It’s both interesting and strange. I think it was like 10 or 20 years ago; there was a bunch of papers that came out that were talking about [fish singing], and it was kind of in the popular press for a while, like ‘Oh, fish sing like birds, they have evening and morning choruses on these reefs’. And [that phrase] was such a reminder that when you are learning about these things you have never heard about before every little assumption can be upended. And if you think about it, it’s true. Ears evolved in the water. Fish evolved the first ears. Birds do sing like fish. And it just was such a cool reminder to always keep asking questions. Every time I’m in or near the water, it just makes it so much richer.