Jonathan Balcombe, What A Fish Knows


Jonathan Balcombe HeadshotJonathan Balcombe is the director of animal sentience at the Humane Society Institute for Science and Policy and the author of four previous books, including Second Nature and Pleasurable Kingdom. Visit his website at and follow him on Twitter at @Jonathanpb1959.

Caryn Hartglass: Hello, everybody! I’m Caryn Hartglass, and it’s time for It’s All About Food! It’s all about food. Ah, how long can you go without food? That’s how important it is. I know I’ve spoken about fasts before. It just came to my mind, how long can you go without food? I know that I can go at least three weeks without food because I did a three-week water-only fast probably about 15 years ago or so. And it was a fascinating experience, but I’m not saying that we should go without food.

Unfortunately, there are many people who do go without food and they’re not doing it for any intentional reason. They’re hungry and there are many people who get very little food. And we talk a lot about food on this program. I love talking about delicious food, healthy food, and I know that I am very fortunate and privileged to have access to an abundance of healthy, delicious food. And I know that there are many that don’t. I’m aware of that, when I encourage you to eat healthy, delicious food and to enjoy the recipes that we put together at

But I always keep in mind that there are those that don’t have this privilege. And it’s always fascinating to think every time we sit down to eat – and I know most of us don’t do this, and I don’t do it enough – to really think about where our food comes from. It’s a fascinating journey to take, and I repeat suggesting to go through this because it’s something that we can easily take for granted and it’s fascinating.

Hello, Jonathan! Are you there?

Jonathan Balcombe: Hi, yes I’m here.

Caryn Hartglass: Great, yes, good. So I’m glad that I got you. I was just talking while waiting for you and I need to give you the appropriate introduction; how important it is to think about where our food comes from, and it’s so easy to take for granted when we have access to healthy, delicious food all the time, for those of us who do, to not realize the long chain, the long journey, all the people and nonhuman animals that are involved in getting the food on our plate to our mouths.

Jonathan Balcombe: Yes, indeed.
Caryn Hartglass: I like to say tune in live and tune in love – that’s what we do during this program.

Jonathan Balcombe: Very nice.

Caryn Hartglass: I imagine that you are extremely busy today because your new book, What a Fish Knows, was released today. Congratulations.

Jonathan Balcombe: Thank you. It’s nice to – after four years of work, it’s nice to finally actually have it fully in the public eye.

Caryn Hartglass: Now just so my listeners know, Jonathan Balcombe is my guest and he is the director of Animal Sentience at the Human Society Institute for Science and Policy and the author of four previous books, including Second Nature and Pleasurable Kingdom. And he has a website, And you can follow him at Twitter @jonathanpb1959. I’ve read your book, and it’s been an absolute pleasure to read it. Every page brings magic and wonder. It really exposes us to the greater – it’s like there’s another universe here on our own planet, which is the ocean. Something we know so little about and we’re just starting to discover, and you shared so much of the little that we know today, about the life underwater.


Jonathan Balcombe: Well I can tell you, Caryn, one of the delights of writing this book was the discoveries that came along on the way. I wrote the book for two primary reasons. One of the key reasons was that there’s so much great science on the inner lives of fish now, but most of it never makes it to the public eye. It’s buried away in scholarly journals and once I started working on it, there were just so many more discoveries, as I went along, that were very exciting. It was exciting to discover a new study of individual recognition or social behavior or sexual behavior or personalities in fish and know that I would be able to work that into my book and that I was going to putting something together that the people could see and just, hopefully, just open their eyes and realize just how rich these animals’ lives are, and how we underestimated them.

Caryn Hartglass: Well, let’s put the idea of eating fish aside for a moment. I want you to know I am vegan and I promote a plant-based diet and we talk about eating nonhuman animals and what that does to the planet all the time on this program. But putting that aside, why is it that a lot of this research has been unheard of and doesn’t get a lot of media attention? Because I really think people would love to hear this information. It’s fascinating!

Jonathan Balcombe: Well, I guess it sort of works in my favor that it has been shrouded in a bit of mystery. It’s a great question, and I don’t have an immediate answer because the press, certainly these days, you see more and more really cool animal stuff in the news. I mean, I can mention two animal studies that have come across my desk in the last week on fish themselves. One is, a couple of days ago I saw a new published study, which is pretty sad and tragic, that farmed salmon become severely depressed. It’s very common. There’s these dropout fish; they give up. They just float to the surface, and they’re listless and they don’t eat. The other fish are three times as big. They basically wither and die. The scientist measured the cortisol levels in these fish – that’s a hormone associated with stress, and you could say misery – and the cortisol levels were way higher in these dropouts, these apparently depressed fish. They showed all the hallmarks behaviorally and physiologically of what we define as depression in mammals. And I do write about emotions in the book. So that’s one study.

The other study that just came to light, just today, is a new study of archerfish, which are really cool and I dedicate several pages of my book to them. They’re called archerfish because they hunt by – they catch food in the water, but they also, if the opportunity arises, they’ll squirt water out of their mouths into the air and actually pick off flying insects or insects perched on a leaf with great accuracy. And they learned this by observing other fish doing this. It’s pretty remarkable, but they’ve just been found to recognize human faces. It frankly doesn’t surprise me, Caryn, that they can do this because, as I describe in my book, individual fish are very good at recognizing individuals in their society. They have their soul mates; they have their preferred individuals to hang out with. They’re very visual in many cases, and so not surprisingly to me, they can recognize a human face and distinguish that face from another human face.

Caryn Hartglass: There are too many things that we have assumed as humans – that we have assumed as we think being the most intelligent things around – that other living species cannot do all the wonderful things that we can do. And it’s really a very ignorant assumption, and an arrogant assumption, and every page in your book talks about the amazing things that we’ve taken for granted about the life underwater. You just mentioned recognizing faces. You’ve shown – and the studies have shown – that fish can recognize their own, their community, as well as when they’re in a tank, they can recognize some of us. I’ve just been fascinated by this book, and the fact that fish use tools.

Jonathan Balcombe: Do you want me to elaborate on that?

Caryn Hartglass: I would love you to because that’s one of the things that has been exploding these days with land animals using tools. That was supposed to be the evidence that we were so superior to everything.

Jonathan Balcombe: I want to preface that by just saying there absolutely is a huge amount to celebrate about humans. We are a remarkable species, we have a number of characteristics that I think are fairly unique to us, but we have to realize that other creatures also have their wonderful characteristics, and they also have their uniquenesses, if you like. In fact, I think we should celebrate the fact that fish are so vastly different from us, and yet they are our cousins – I deliberately use cousins in the subtitle of the book to provoke, but also to remind readers that, they are members of the vertebra clan. They are direct links to us. I was about to say “ancestors”; I actually don’t like that word because evolution is ongoing. It’s not as if fish stopped evolving when the first ancestor of mammals and birds and terrestrial animals crawled out of the water a couple hundred million years ago. No, they have continued to evolve and flourish. In fact, we are in an age of fish. The age of mammals is long past. The fish are the ones who are most diverse today.

Let me speak about tool use. It’s something that we don’t generally associate with fish, and I try to present a number of – I present a number of things in the book that might raise eyebrows when you consider that fish actually can do these things. But fish that have the disadvantages of not having grasping limbs and fingers and such, they are limited in the kind of tool use they can express, but in fact they can use their mouths. They can also blow water with – well, I already mentioned the archerfish – their mouths, shoot water out of their mouths and catch things. That’s a form of tool use. But they can also push water with their mouths or gills, and they can uncover mollusks that way.

So an example of tool use would be triggerfish or a wrasse or some other species of fish – tusk fish – who will deliberately blow water, either with their mouths or their gill covers to uncover the sand and uncover the mollusk and then pick the animal up with their mouths and then swim very deliberately to a rock that they will use as an anvil with a series of well-coordinated, well-timed head flicks and releases, which is not easily done, they are able to smash the unfortunate mollusk against the rock to get the soft insides. It’s a very deliberate sort of behavior – you can watch YouTube videos of this – and it’s being published. There are other examples of tool use in fish that are being published now. It seems to involve planning. I present it as such in the book, that the fish actually thinking ahead, knows exactly what he or she is doing, knows the ultimate goal, but there are several steps to get there. So it’s more than tool use, it’s planning and wherewithal and consciousness and all those other things that we often forget that fish have.

Caryn Hartglass: What I learned in your book about community or all of the cultures that are going on underwater and how the fish interact with their same species and different species; It was all wonderful to read, but at the same time I was a little frustrated to know that the same negative traits that we have in our own human communities, you can see them underwater as well. There are positive traits, and not so positive traits.

Jonathan Balcombe: Indeed. And I think that’s another part of the beauty of the lives of fish, is that they are mirrors to us and vice versa. They are fallible, they fall for the same kinds of optical illusions that we do, for instance, and I present some of those in the book. They are sometimes mean to each other, there’s certainly predation that goes on. I do like to, having written a couple of books on animal pleasure, I do also often like to see animal behavior through a pleasurable lens and there’s plenty of that. I do describe cleaning stations on reefs where client fish line up to wait their turn to be serviced by cleaners of various species who pluck over them, removing parasites and sloughing skin and algae and that sort of thing. It’s a classic mutualism; the cleaner gets some food and the client fish gets a spa treatment, and they appear to love it. They sometimes change color; they will pause while the cleaner fish takes a break from cleaning and actually just fortuitously give them some caresses with their pectoral fins, which probably feels good. They’re not doing that for nothing because they want to curry favor with the clients because they want those clients to come back. So there are clear behaviors that are built on the capacity to feel pleasure.

But as you said in your question, I mean it’s Machiavellian under there. In fact the cleaners-client relationship is complicated because you get cheaters, you get cleaners who do not such a good job. Careful studies have shown that cleaners are very well aware of who’s watching them and how many other potential clients are watching them. Just as you might expect a better job or better service from a barber who has a number of people waiting to get a haircut later than if there’s no one there watching or waiting, you get better treatment from cleaner fish when they’re being watched by clients. And why is that? Well, clients are actually forming image scores and keeping a count of the cleaners performance – I’m not making any of this up, it’s all described in published literature – because they can go somewhere else, go to a different cleaner. And so, cleaners are more likely to nip off a little mote of mucus from the client if no one’s watching them because there’s less of a cost, because they’re not going to lose potential future clients if there’s no audience. So this is the kind of Machiavellianism – that’s the term that a biologist used, another biologist in one of his papers that I thought was a very appropriate term. There are pluses and minuses, there’s awareness of others, there’s reputations at stake, and not everyone always behaves well.

Caryn Hartglass: Now a lot of this information has come from studying fish in ways that cause them harm or cause them pain. And there’s some sort of – I don’t want to use the word balance; we learn a lot, but at the same time it’s quite cruel.

Jonathan Balcombe: Yeah, and I often get asked by audience members when I speak about animals. People ask me, “You know, I noticed you cite some studies that are not very nice,” and my response to that is, “Indeed, I wouldn’t really been keen to do those studies myself. In fact I’m a co-editor of an new journal called, Animal Sentience, in which we encourage authors to be mindful of not harming animals in their studies, and using positive reinforcement and rewards rather than punishment like starvation to motivate behaviors and that sort of thing; and to release animals back in the wild if they took them captive. This sort of thing. But nevertheless, given that other people have taken pains to do studies and they’ve maybe caused some fish to suffer, or even die in some cases, I feel that it honors fish more if I bring those studies to light, not as an endorsement but to hopefully use the information gleaned from those studies to advance the cause so that in the future we’ll have more in-line view of these creatures and be less inclined to do harmful things to them. So it’s a little bit tricky, but that’s just my view. It’s kind of utilitarian view.

I think that there’s a lot of studies that I also cite that are not harmful, and the people who did the study went to lengths to make sure they didn’t harm the fish. There’s a growing number of scientists reporting now that they are returning their creatures back to the wild and I’m very impressed to see that because I can tell you that’s still a rarity in science, that they even report on whether they do it or not.

Caryn Hartglass: Well, the analogy is doing tests on nonhuman land animals and then using that information to understand human health and all issues around humans as well. There’s that question of whether to use that information or not, and many people do because it’s available, not that we necessarily – some of us – encourage that sort of thing.

Jonathan Balcombe: Yes.

Caryn Hartglass: Okay, so how can we study what’s going on underwater without harming the life there? Are there some more organizations that are doing that?

Jonathan Balcombe: There’s a new organization called Fish Feel.

Caryn Hartglass: Oh, we just talked to Mary Finelli a few weeks ago.

Jonathan Balcombe: Good, yeah. So it’s nice to see that. There’s some organizations in Europe that are working to try to change laws about fish, particularly in reference to commercial fishing, which is something that’s going to be going on for some time yet, but it’s deeply disturbing what is done to the animals who are caught in that industry. Also the fish farming agriculture, which is the fastest growing food-production sector on the planet for the last number of years. There are changes in some practices going on. These are very much welfare-reforms. We’re not talking about someone acknowledging that fish have rights and they deserve to be left along, not exploited at all. But nevertheless, I do believe in an imperfect world that we need to work for changes on all fronts, at all times. So, welfare changes are better than no changes at all in my book. It’s important that we keep plugging ahead, and one of the things I try to do in the book is juxtapose the science of what we now know that reveals these creatures as individuals with rich lives, with not just biology but biographies. I juxtapose that with the really frankly appalling that we mete out on them, not because we’re cruel, but because we’re indifferent in the production of commercial fishing and recreational fishing, in many cases. It’s not nice, the way we treat them. It’s really nasty being hooked through the face, often through the eye, inadvertently, and then hauled up by your own body weight to the surface and then depending on what the situation is, worse things happen to you after that. It’s pretty awful. If we were doing that to mammals on land there would be quite an outcry. And of course, at our worse, we do horrible things to mammals as well. In any event, it’s my hope that people will see that these animals are aware, they’re alert, they’re individuals, they have personalities, they have lives worth living for them, and that because of that we have to start including them in our circle of moral concern. We’re a moral creature, we’re stuck to that, we have a sense of ethics, we know what right and wrong is, and right now how we treat them is wrong. We need to take that into consideration in our future behavior.

Caryn Hartglass: I not exactly sure how to describe how you do it, but with your writing you make this horrible information very real.

Jonathan Balcombe: It has to be. If people are disgusted or put off they’re going to put the book down, and they’re going to go no further. I mean, I can’t speak for everybody; we’re a very mixed bag. So just as the fish are a very mixed bag, so are we. But I want to reach as many people as I can and it’s important that there be levity, it’s important there be joy in the reading. And of course, if you’re writing about the way we treat fish in commercial fishing, it isn’t exactly joyous, but I try to keep it flowing and tell stories as well as relate the science because people have to be motivated to want to change. This world is a wonderful world and we have to make it better. This is not about, “Oh it’s so horrible. Let’s just throw our hands up and give up,” it’s about, “We can do so much better, and we shown that we can do that in the past.” That’s why it’s so important to keep a positive outlook on this stuff.

Caryn Hartglass: You mentioned the movie, Finding Nemo, a number of times in the book. You do have a lot of humor in the book, which I enjoyed very much. I love this film, Finding Nemo, and one of my favorite lines in the film is, “Fish are friends, not food.” Are there some things that are beneficial from this film? You mentioned a number of times that they took a lot of liberties, but somehow I think that just being able to see, even though it’s a cartoon, the possibility that the life under the water can work together, helps us understand that a little more.

Jonathan Balcombe: Yeah it’s a great question, and I’ve seen the film and this book is strategically timed to coincide with the release of the sequel, Finding Dory, which is coming out in about ten days time. I’d like to think that these films can improve our attitudes towards, in this case fish. Of course there are harms as well. There’s already a campaign with Humane Society at the national and tent watch, for instance to encourage people, or discourage them, from going and actually finding Dory, which is to say going to a pet shop and buying the tangs, which are featured in the film because blue tangs are very vulnerable in their natural habitats so most of them that are in the aquarium trade are taken from the wild. It’s grim. The aquarium trade, there’s a lot of mortality; the shipment conditions are often terrible, the conditions and the methods with which they catch them are really bad. So that’s the negative side, but I do like to thin that these films, because they personalize fish so much, that in juxtaposition with, hopefully my book, that people can see that actually, they are quite a bit like us in many ways. In a vacuum, they may not make that connection, but with the information that I hope people will get from the book, those who actually read the book and watch the film, that the film actually will help to advance attitudes and make people more sensitive and concerned with these creatures.

Caryn Hartglass: Other than reading your book, which I think everyone should do honestly, what can people be doing now to help underwater life, which really affects all life? Because without them, we can’t survive either.

Jonathan Balcombe: Yeah, well I think it’s important to meet people where they are and to get them moving forward. If people are say, Pescetarians – they’re vegetarians but they accept that they still eat fish, which are definitely animals – stop eating fish would be a great step. If they are fisherman, then consider stopping fishing or taking up bird watching, or if you’re going to keep fishing, replace your barbed hooks with barb-less hooks. Or take your barbed hooks and crimp them with a set of pliers so they are no longer barbed. There are steps anywhere along the spectrum that people can take to make things better for fish.

Caryn Hartglass: Well Jonathan Balcombe, thank you for joining me on It’s All About Food, and for writing this book, What a Fish Knows: The Inner Lives of Our Underwater Cousins. Congratulations on your release of this book.

Jonathan Balcombe: Thanks for having me, Caryn.

Caryn Hartglass: Okay, take care.

Jonathan Balcombe: Bye.

Caryn Hartglass: Bye.

Transcribed by KP, June 18, 2016

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