Exploring The 'Wild And Haunting World Of Dolphins'

Aug 4, 2015
Originally published on August 4, 2015 4:28 pm

Dolphins tend to strike a deep emotional chord in many people who encounter them. Famous for their intelligence and physical ability, there have been reports that the marine mammals have come to the rescue of humans at sea.

Writer Susan Casey tells Fresh Air's Dave Davies about an instance in which a scientist who was watching dolphins hunt noticed that they suddenly bolted for deeper water. He followed them and found that the dolphins had formed a circle.

"In the center of the circle there was a young girl floating with a suicide note," Casey says. "And she was very close to dead, but she wasn't dead. ... The girl was saved."

In her book, Voices in the Ocean, Casey describes the world of dolphins and addresses the myth that dolphins have healing powers. She also details the threats the animals face from man-made sounds in the ocean.

"Underwater noise in the ocean is a big, big problem and it's growing," she says. "The good news is there seems to be more awareness of how harmful it is, particularly to animals that live and die by their acoustic senses, like dolphins and whales."


Interview Highlights

On dolphins' ability to understand word order

One of my favorite facts about dolphins is that ... they understand that if I say "Take the hoop to the surfboard, then get the ball," it's different than "Take the ball to the surfboard, then get the hoop," or any number of complex changes in sentences. Any number of quick changes with wording that changes the meaning of a sentence, the dolphins were able to pick that up very quickly.

On controversial dolphin researcher John Lilly

This was the '50s. He was able to experiment on dolphin brains in a way that we would find extremely awful now. ... The '50s was a pretty rude time for brain research; it was vivisection, it was experimenting on live animals. His first outing with dolphins, he killed dolphins basically in one long session, because at the time nobody understood that they won't breathe involuntarily like we do. They take in breath as a decision because they're underwater, they need to be able to time when they breathe. ...

The real colorful part began when he got a lab in the U.S. Virgin Islands ... with these buildings that were set up to observe dolphins and in some cases half-flooded with water so that humans and dolphins could be there together, and he began this wild period of experimentation with dolphins, and at some point along the way picked up LSD to try to better commune with the dolphins.

On a co-habitation experiment with Margaret Howe

She believed, like [John Lilly] did, that if you had enough contact with the dolphin, particularly if it was a young dolphin, in the same way that a mother might raise a young child, then you could eventually teach them our language, you could teach them to speak English.

So after a little bit of theory and experimentation, they set up an environment where Margaret lived with a young male dolphin named Peter for 10 weeks in a house that was flooded with 24 inches of saltwater, so they were always together. And there was a very strict schedule; there were math lessons, pronunciation, grammar, even manners, and things went sideways pretty quickly in the flooded house. Margaret was made aware very quickly of the dolphin's needs, he began to pursue her sexually. ...

At one point she writes, "He does not go away" and she italicized it and underlined it, and so she said, "I carry a broom handle with me to ward him off," but the dolphin was innovative and he knew what he wanted and after a while Margaret decided, "Well, this would certainly create a closer inter-species bond," so she began to address his desires in probably very creative ways. It doesn't get that specific in the notes, but we probably can imagine.

On the notion that dolphins have healing powers

I think that where the problem is with this notion of dolphins healing people is this idea that you can come with a child who may have autism or may be otherwise ill and you pay $5,000 or some extraordinary amount of money and they get into a swimming pool with a dolphin and somehow they're going to be fixed, and that is not supported by science at all. It's of course a novel experience, it's a charismatic animal, it's something that would be fun to do under any circumstance, but this idea of putting more dolphins into concrete tanks and charging astronomical fees and promising something that is really not being delivered, it really is kind of shameful.

On dolphins being slaughtered in organized hunts

In Taiji [Japan] it's very clearly motivated by money. It's one of the largest traffickers of live dolphins in the world. They have often said that it's a tradition, this hunt. It is not a tradition. It began in 1969. They do have a whaling tradition, but they did not have a dolphin-hunting tradition until then, so it's really relatively recent. When you go there you see this small group of fishermen that are rounding up dolphins ... in this cove ... and there are dolphin brokerages and there's a whaling museum there that brokers dolphins for sale to marine parks around the world. There's also a large number of dolphins that are killed and sold for meat. ...

In the Solomon Islands they're hunting dolphins in a traditional way, they really do have a tradition of hunting dolphins. It's a really rough place ... and very poor, they do eat dolphins there, but they also use the teeth as a currency. The teeth are used to buy brides and cigarettes and things.

On military sonar and harmful underwater noise

Some of the loudest noises are the military combat sonar, which in certain species of dolphins has caused beaching, it's caused hemorrhage of the brain, embolisms, it's killed a lot of dolphins when they're close to it. In particular, it affects some of the deepwater species that it's so loud they end up rushing to the surface, and even though they are very adapted to being at depth they can still get the symptoms that we would associate with the bends. ... Several environmental groups have taken the Navy to court a couple of times, most recently successfully, in California and Hawaii, when the Navy said they were going to start using the sonar a lot more in that region.

Copyright 2015 NPR. To see more, visit http://www.npr.org/.

Transcript

DAVE DAVIES, HOST:

This is FRESH AIR. I'm Dave Davies, in for Terry Gross, who's off this week. If you wanted to find my guest, Susan Casey, the first place you'd probably look is in the water. She spends a lot of time on the ocean, where she researched a best-selling book about sharks and another about huge ocean waves and her latest about the remarkable lives and abilities of dolphins. Dolphins are marine animals of great intelligence and physical ability who've been known to come to the rescue of humans at sea in some pretty surprising circumstances. And, Casey writes, they strike a deep emotional chord in most people who encounter them.

In her new book, she shares some fascinating research about dolphins and describes new threats they face, from organized dolphin kills to man-made sounds in the ocean that wreak havoc with the animals' highly sensitive echolocation systems. Susan Casey's work has appeared in Sports Illustrated, Outside, National Geographic and other publications. Her books include "The Devil's Teeth," about sharks, and "The Wave." Her latest book is "Voices In The Ocean: A Journey Into The Wild And Haunting World Of Dolphins." Well, Susan Casey, welcome to FRESH AIR. I thought we'd begin with a remarkable experience that you have, and you begin the book with this. Why don't you just describe what was happening when you were taking this swim and then do this reading for us?

SUSAN CASEY: I was by myself, at a time in my life when I felt very lost - extremely alone. I had lost my father very suddenly. He died of a heart attack, and it had set my world just back on its heels in such a big way that I didn't really know how to proceed. But the one thing that always makes me feel better is to go into the ocean. That's my place of solace. That's my church. So I had driven to a part of Maui. I was visiting the island, and it's a place I'd been before, a long way away from where was staying. And when I got there, the weather was uninviting. The water would look kind of choppy and surly. There were gray clouds, but I decided to go for a swim anyway. So it wasn't very comforting that I saw a big dorsal fin attached to a large shadowy body next to me, and that's the passage I'll read.

DAVIES: Go ahead.

CASEY: It was a pod of spinner dolphins - 40 or 50 animals swimming toward me. They materialized from the ocean like ghosts, shimmering in the ether. One moment they were hazily visible, then they were gone, then they reappeared on all sides, surrounding me. I had never been this close to dolphins before, and I was amazed by their appearance.

One of the bigger spinners approached slowly, watching me. For a moment, we hung there in the water and looked at one another, exchanging what I can only describe as a profound cross-species greeting. His eyes were banded subtly with black, markings that trailed to his pectoral fins like an especially delicate bank robber's mask. I wondered if he was the pod's guardian, if others followed his lead.

The dolphins were traveling in small but distinct clusters - couples, threesomes, klatches of four or five - and within those little groups, they maintained close body contact. I saw fins touching like handholding, bellies brushing across backs, heads tilted toward other heads, beaks slipped under flukes. The entire group could have darted away in an instant, but they chose instead to stay with me.

Spinners are known for their athletics, rocketing out of the water in aerial leaps whenever the urge strikes, but these dolphins were relaxed. They showed no fear, despite the presence of several baby spinners tucked in beside their mothers, replicas the size of bowling pins. The dolphins had simply enfolded me in the gathering, and I could hear their clicks and buzzes underwater, their cryptic aquatic conversation.

I dove 10 feet down, and the big dolphin appeared beside me again, even closer. He had coloration like a penguin's - dark on top and tuxedo white on his belly, with a long slender beak. At eight feet long, he was a powerful animal, but nothing in his body language suggested hostility. We stayed together for maybe 10 minutes, but the meeting felt eternal, as though time were suspended in the water with us.

DAVIES: And that's our guest, Susan Casey, reading from the beginning of her book, "Voices In The Ocean: A Journey Into The Wild And Haunting World Of Dolphins." So let's talk about these animals. Where do they come from in the evolutionary chain?

CASEY: They are such old animals. The last ancestor that we had in common with them - us being primates - was 95 million years ago. Then we - at 55 million years ago, they came off the land and went into the ocean. And at the time, when they were land mammals, they looked like, apparently, small, hoofed wolves, so I found that a kind of an interesting combination to begin with. But then these small, hoofed wolves slipped into the water and began a completely different evolutionary trajectory.

Thirty five million years ago, their brains changed size dramatically and became much larger. At the same time, their bodies became much smaller, and they developed all the equipment that they needed to live full-time underwater. And this has been going on - their evolutionary journey - odyssey, really - has been going on for so long that, at this point, they've just got it down. Everything they need to be in the ocean, to be perfectly adapted to the ocean - they have it now.

DAVIES: You encounter some interesting characters. I mean, dolphins are interesting, and you encounter some interesting characters as you set out to learn more about them. And you look through the files of a researcher named John Lilly. I think he passed away in the early 2000s. Tell us a bit about his work.

CASEY: His career trajectory was unusual. He started off in a really sort of rigorous scientific way, with being a neuroscientist, a commission surgeon. He was trained in psychology and, when he saw his first dolphin brain, had found his grail. It was - here was a big, interesting brain. It was built differently than the human brain, but it was clearly - meant serious business, and they were available. These animals were available. This was the '50s. He was able to experiment on dolphin brains in a way that we would find extremely awful now and was extremely awful then, too. But he started working with dolphins, and within a very short period of time, sort of reeled at how sophisticated, how intelligent and, you know, how unusual they were in his sort of pantheon of animals that he had had in his lab. They were completely different. They were always wanting to communicate with him. And that began a phase of his career where he really kind of went off the reservation.

DAVIES: You said that some of his methods would've troubled us today. What did he do to their brains to learn about them?

CASEY: Well, in the '50s - the '50s was a pretty rude time for brain research. It was vivisection. It was experimenting on live animals. He had - his first outing with dolphins, he killed five dolphins in basically one long session because at the time, nobody understood that they don't breathe involuntarily like we do. They take in breath as a decision because they're underwater. They need to be able to time when the breathe. So when you anesthetize a dolphin you basically are killing it unless you can somehow put in a breathing apparatus, and nobody knew that. So he would - wanted to experiment on their brains. He would try to give them anesthesia or Nembutal, and they would die. And then, once they figured that out, actually, his method was to hammer steel sleeves into their skulls.

DAVIES: He popularized images of dolphins a lot. I mean, he wrote books which were widely read and developed a public, you know, kind of affinity for these animals, but he also got kind of weird (laughter).

CASEY: Yeah.

DAVIES: What are some of the other things that he did that were a little more notorious?

CASEY: Well, in the - it started right at the beginning. He began to throw out a lot of pronouncements about dolphins - that they were most likely more intelligent than we were, that they had all kinds of abilities that could help us. Maybe they could teach us about space. You know, they could certainly be taught to speak English. They - once we could speak to them, they would probably do all kinds of stuff for us in the oceans, like bring deep-water species up for us to examine and maybe deliver rocket - deliver missiles. Or - I mean, he had this whole list of things that we would have dolphins do for us. And unfortunately for Lilly, he didn't really have any proof - scientific proof - to back up back up a lot of his boldest assertions.

The real colorful part began when he got a lab in the U.S. Virgin Islands. And somehow - I don't think you would see this happening today - but somehow it had an oceanfront property with these buildings that were set up to observe dolphins and, in some cases, flooded - half-flooded with water so that humans and dolphins could be in them together. And, you know, he just sort of began this wild period of experimentation with dolphins and, at some point along the way, picked up LSD to try to better commune with the dolphins. He had pointed out, rightly, that this was a mind that was completely different than our mind. It had evolved for a lot longer than ours had. It basically was working in very different ways. And in order to be able to understand anything about it, we would have to sort of throw off the ties of our own consciousness and our own restrictions and get in sync with, I mean, just sort of inner space (laughter).

DAVIES: So he would take LSD. And did he give the animals LSD, also?

CASEY: He did. He wrote an entire book about that, and he himself would float in his flotation tank, which he also had invented.

DAVIES: He also had a cohabitation experiment with a woman, Margaret Howe. What was that all about?

CASEY: This is - whenever I speak about my book, this is always what people want to talk about (laughter).

DAVIES: (Laughter).

CASEY: Margaret was a very game woman. She came to work in the Communication Research Institute, that was the name of his lab. And she believed, like he did, that if you had enough contact with the dolphin, particularly if it was a young dolphin, in the same way that a mother might raise a young child, then you could eventually teach them our language. You could teach them to speak English.

And so after a little bit of theory and experimentation, they set up an environment where Margaret lived with a young male dolphin named Peter for 10 weeks, in a house that was flooded with 24 inches of saltwater. So they were always together, and there was a very strict schedule. There were math lessons, pronunciation, grammar, even manners (laughter). And things went sideways pretty quickly in the flooded house. They - Margaret was made aware very quickly of the dolphin's sort of needs. He began to pursue her sexually.

DAVIES: This is a fascinating part of the story, and I don't know how graphic we want to be. But in the notes, it appears that the dolphin would follow Margaret Howe around, aroused. How did she deal with it?

CASEY: (Laughter) Well, her notes are - I mean, reading through her notes is both hilarious and horrifying at the same time. And at one point, she writes, he does not go away, and she italicized it and underlined it. And so she said, I carry a broom handle with me to ward him off. But, you know, the dolphin was - he was innovative, (laughter) and he knew what he wanted. And after a while, Margaret decided, well, this would certainly create a closer interspecies bond. So she began to - she just began to address his desires in probably very creative ways. It doesn't get that specific in the notes, but one can imagine.

DAVIES: And so did we learn something from that or from any of these experiments with, you know, mind-expanding drugs that advanced our understanding of dolphins?

CASEY: Well, I think, you know, Lilly is so fascinating because he's so polarizing. There's something so wonderful about his imagination in terms of - what could possibly be going on with an animal that's had a big brain for 35 million years and adapted perfectly in the dominant ecosystem on Earth? Something really cool could be happening in that brain. There is just no doubt about that, and we are just sort of starting to understand more about it. But at the same time, he was pretty freewheeling about the things he did and the things he said. And a lot of scientists believe that he set back research on dolphins quite a long way.

So there was this weird sort of polarization in Lilly's character where half the culture - the nonscientific culture - were just absolutely enchanted by the notion that dolphins were these others - these amazing - and this - they are. They are amazing alien species - highly intelligent - here on earth. And then the scientists, of course, you know felt that what he was saying was so very far away from anything we could prove that, you know, they basically - he was discredited. And his methods - his drug taking, his - some of the experiments that he did - you know, those weren't necessarily helping science in any way.

DAVIES: Susan Casey is our guest. Her book is "Voices In The Ocean." We'll continue our conversation in just a moment. This is FRESH AIR.

(SOUNDBITE OF MUSIC)

DAVIES: This is FRESH AIR, and if you're just joining us, our guest is writer Susan Casey. She's written a lot about about the ocean. Her latest book is about dolphins. It's called "Voices In The Ocean." OK, now, serious researchers have, you know, documented some pretty remarkable things about these animals and what they can do and learn. For example, language - tell us about some of that.

CASEY: One of my favorite facts about dolphins is that they understand syntax in sentences. They understand that if I say take the hoop to the surfboard, then get the ball, it's different then take the ball to the surfboard, then get the hoop or any number of complex changes in sentences. Any number of quick changes with wording that changes the meaning of a sentence - the dolphins were able to pick that up very quickly. And the experiments that I'm speaking of were done in Honolulu by a scientist named Lou Herman, and these were phenomenal experiments. They took place from around 1980 to the early 2000s, and he was very rigorous. He proved a lot about dolphins being able to understand and communicate to us in ways that Lilly hadn't because he attacked it so rigorously.

And he, you know, some of the things that he was able to determine were that they can understand concepts like presence and absence. Or, you know, they could listen to eight sounds in a row, and then they would use their flippers to press paddles to say whether - yes or no - the ninth sound had been played previously. They could discern all kinds of things. When they were asked to innovate, they immediately began to do behaviors that they haven't done before. They understood what that meant. So there were these subtle conceptual things in language that they understood, and they pick them up fast. So...

DAVIES: And I love that there was another one where he would ask them to do something that was completely impossible, like take me into the tank or something. And they would just stare back, like - what? Are you kidding me? (Laughter).

CASEY: Right. When they were given instructions that they could not execute or that were not possible to execute, they wouldn't even try. They could - they could - at the end, I believe they understood something like 2000 sentences. And, you know - and he also noted that when new instructions were given - brand new instructions that they had never heard before - their performance wasn't any different than rote instruction. So they picked up new things quickly, as well.

DAVIES: There are some remarkable stories of them coming to the assistance of humans in the ocean. You want to share a couple of them?

CASEY: My absolute favorite story comes from a scientist who was studying a pod of bottlenose dolphins along the coast of Los Angeles. One gray foggy morning, she was in her research boat, trailing along as they were just doing their average hunting, looking for fish. And they hunt in a kind of formation, and when they find the fish, then they - every dolphin has a role to try to work cooperatively to make sure that all the dolphins get to eat.

So they found a large group of fish, and they were finally going to get to feed. One dolphin broke away and started just swimming at top speed out to sea. The other dolphins followed, and they went for quite a while. And the scientist followed them because it was unusual behavior. You don't see dolphins hunting for fish, finding them up and then taking off very often.

So they got about three miles out to sea in the fog, and the dolphins had formed a circle. And the scientist looked, and in the center of the circle, there was a young girl floating. She had a plastic bag wrapped around her neck with a suicide note and her ID. And she was very close to dead, but she wasn't dead. And the dolphins had basically led the scientist directly to her. And it was far enough offshore that it was just one of those, how do you describe - how do you explain that? I - it's thinking about that story and knowing that it was a scientist observing it. That to me is enough to really make me want to understand more of what's going on with these animals.

DAVIES: The girl was saved. The suicide was averted.

CASEY: The girl was saved.

DAVIES: Yeah. A lot of people believe that they have enormous healing powers, right?

CASEY: Yes. People do tend to believe this, and I think any time you're in the wild with a beautiful animal, you're going to feel good. It certainly was wonderful for me to have this sort of encounter that I had. Did they do something special with their sonar that zapped me and make me happy? I don't think so. I think it was the whole environment. This notion that there were these others, particularly in the ocean - it was this unexpected encounter with some sort of intelligence that I could sense and that seemed to be sensing me.

Now, I think that where the problem is with this notion of dolphins healing people is this idea that you can come with a child who may have autism or who may be otherwise ill, and you pay $5,000 or some extraordinary amount of money. And they get into a swimming pool with a dolphin, and somehow they're going to be fixed. And that is not supported by science at all. It's, of course, a novel experience. It's a charismatic animal. It's something that would be fun to do under any circumstance, but this idea of putting more dolphins into concrete tanks and charging astronomical fees and promising something that is really not being delivered is - it really is kind of shameful.

DAVIES: Susan Casey's new book is called "Voices In The Ocean." Later on, we'll hear about some people who think dolphins come from outer space, and she'll share some other stories with us, including a frightening encounter she had with a tiger shark. I'm Dave Davies, and this is FRESH AIR.

(SOUNDBITE OF MUSIC)

DAVIES: This is FRESH AIR. I'm Dave Davies in for Terry Gross, who's off this week. We're speaking with Susan Casey, who writes a lot about the ocean and whose new book is about the remarkable lives and abilities of dolphins. It's called "Voices In The Ocean: A Journey Into The Wild And Haunting World Of Dolphins." When we left off, we were talking about how some people believe dolphins have special healing powers, but many of their claims aren't supported by science.

Some dolphin enthusiasts have some pretty - what would we say? - unorthodox views of who they are and what they represent. You went to this place in Hawaii - Dolphinville - where there was an interesting gathering. You want to tell us about that?

CASEY: Well, Dolphinville is more a state of mind than a place, but it is sort of centered along the Kona coastline, where there's a really regular population of spinner dolphins that come into the bays during the day. And there are a lot of people that come into the water to swim with them because they're pretty reliably found there. And among them is a group of people who sort of loosely refer to themselves as Dolphinville who spend as much time in the water with the dolphins as they can.

And they're basically bonded by New Age beliefs about dolphins and - that dolphins are sort of highly evolved beings that have messages of wisdom and love and all kinds of different things to teach us. And they gather. They meditate. They swim with the dolphins. And I wanted to go spend some time with them because one of the big questions that I had when I began my reporting was, what is it about dolphins in particular that has so attracted the New Age movement?

DAVIES: It's clear people feel a connection. You have felt that connection in the water. And as you note, some of these folks that you encountered actually believe that they're aliens, right? I mean, there was talk of alien pods under the water, right? What was your reaction to hearing - I mean, you know, you're there. I mean, you've had these remarkable experiences with these animals. What was your reaction to hearing some of these things?

CASEY: You know, these people are really conscious in the water. I - I mean, they're actually very respectful and very loving and, you know, they're not doing anything to harm dolphins whatsoever. So I found it really enchanting to hang out with them. And there were only a few times when I sort of thought, well, that's clear nonsense. If you hang out with these people long enough, you'll hear a lot of talk about, well, maybe the dolphins came from another solar system. They aren't from this planet. Their sonar actually (laughter) encodes dormant DNA, and they can send messages through it and things like that. They can heal us. There's a lot of that type of belief. And it's, of course, just personal belief - very colorful, personal belief that a lot of people have when they come to hang out with Dolphinville.

DAVIES: Dolphins are dying in a lot of places for a lot of reasons. Most dramatically, there are these dolphin kills, which occur in the Japanese village of Taiji and in the Solomon Islands, as you wrote. What are these motivated by, where villagers herd dolphins into shallow pools and kill them?

CASEY: Well, there's two really different examples. In Taiji, I think it's very clearly motivated by money. It's one of the largest traffickers of live dolphins in the world. And when you go there, you see this sort of small group of fishermen that are rounding up dolphins. It's about a six or seven-month hunting season that starts in September in this cove. And, of course, it was the cove that was in the movie "The Cove," the Oscar-winning documentary. And there are dolphin brokerages, and there's a whale museum there that brokers dolphins for sale to marine parks around the world.

There are also a large number of dolphins that are killed and sold for meat. And dolphins are still eaten in Japan but not a lot. It's not a really popular thing to eat, and it's also very toxic, dolphin meat. It's got a lot of mercury in it. It's got a lot of sort of persistent organic pollutants. Even if you wanted to eat it, it would be very bad for you. So the meat is not a major source of income for the hunt. It's all about selling the dolphins to marine parks. In the Solomon Islands, they're hunting dolphins in a traditional way that they really do have a tradition of hunting dolphins. It's a really rough place - the Solomon Islands - and very poor. And they do eat dolphins there, but they also use the teeth as a currency. The teeth are used to buy brides and, you know, cigarettes and things.

DAVIES: You write about a lot of things that are threats to dolphins, including pollution, including overfishing, which degrades their habitat, and underwater noise, including military sonar. You want to talk a bit about that and why it's so harmful to these animals?

CASEY: Underwater noise in the ocean is a big, big problem, and it's growing. The good news is there seems to be more awareness of how harmful it is, particularly to animals that live and die by their acoustic senses, like dolphins and whales. And some of the loudest noises are the military combat sonar, which in certain species of dolphins has caused beaching. It's caused hemorrhage of the brain, embolisms. It's killed a lot of dolphins when they're close to it. And in particular, it affects some of the deep water species that it's so loud, they end up rushing to the surface. And they're - even though they're very adapted to being at depth, they can still get the symptoms that we would associate with the bends, you know, if you come up too quickly when you're diving.

And several environmental groups have taken the Navy to court a couple of times, most recently, successfully, in California and Hawaii when the Navy said that there were going to start using the sonar a lot more in that region. And the Navy seems really hesitant to set any precedent about exclusion zones. So this is - when the noise is that loud - the military sonar can be as loud as 236 decibels, which is - if we were listening to a sound like that on land, our eardrums would break. It could even cause death. So it's a really painful, loud sound to hear in the water. And, of course, sound travels much faster in the water and much farther in the water than it does on land. The only thing that's louder than the military sonar are the air guns that are used for oil and gas prospecting underwater. And those can do all kinds of damage to all the animals underneath them.

DAVIES: We're speaking with Susan Casey. Her new book is "Voices In The Ocean: A Journey Into The Wild And Haunting World Of Dolphins."

You know, for another book that you wrote - "The Devil's Teeth" - you spent a lot of time with huge white sharks - great whites. You said you encounter sharks out in the ocean, and you love those encounters. Did I get that right? I mean, most of us would be terrified.

CASEY: Yeah. I know. I mean - but, you know, I...

DAVIES: Why aren't you?

CASEY: Well, I was just swimming open-water swim last weekend, and I saw a white-tipped reef shark. It was maybe 5 feet long. It was on the bottom. You know, it was 20 feet down. And there's nothing threatening about it. I did have an encounter with a tiger shark one time that was - it was a little dicey. But at the time, I mean, I did manage to marvel at how beautiful it was (laughter). It looked pretty angry, and it looked - I have to say, I would probably be fine seeing other species of sharks than tigers (laughter).

DAVIES: What happened with that tiger shark?

CASEY: I was swimming with a couple other people, and we interrupted it. It had killed a turtle. And we were swimming in deep water, and we just swam right into it as it was feeding. So it dropped the turtle, and - we saw the turtle first. It looked like a turtle, but it was - there was something wrong with it, clearly. And then we saw the shark right next to us. And it had its back hunched up and its pectoral fins pulled down and its eyes rolled back, which is what they do when they're about to launch themselves at you.

But we just stopped. We looked at it because it's obviously better to see it than not. And the shark sort of angrily swam next to us and around us, but it didn't stay. Two other people swam up behind us and saw that we were stopped, and then they saw the shark. And when there were five of us there, it got a lot less sure of itself. And it dropped down, and it took its turtle, shook it a couple times and swam away. It was a really clear case of a pissed off animal (laughter). And I guess we ran right into its dinner.

DAVIES: You wrote a book about waves and write about these huge, rogue waves out in the ocean, which I didn't realize scientists weren't so sure really existed for a long time. What kind of stories did sailors tell?

CASEY: Well, people came back telling stories about these giant waves that appeared out of oceans in which technically speaking, or physically speaking, they shouldn't have appeared, and people thought those were just mariners' tall tales. That they were just, you know, exaggerations of the sea. Because the scientists will describe a rogue wave technically as a wave that's more than two times the size of the seas around it. And it doesn't seem in a lot of conditions as though that should be possible. But ships were getting damaged and in some cases even lost dramatically and instantly in conditions that nobody could really understand. And it was only a - I believe it was 1983 or so that we had definitive proof that it is possible for an 85-foot wave to leap out of 38-foot seas.

DAVIES: Do you have a particular dramatic story of a rogue wave?

CASEY: The story that I really like and that I began the book with is the story of a research cruise in the north Atlantic that was headed out just to do sort of a transect, doing water sampling from Scotland to Iceland. And the whole boat was ringed with instruments. And they had, of course, all the latest weather reporting equipment, everything in the - entire crew was scientists. So they had their weather forecast, and they set out. And somewhere off the coast of Scotland, they encounter this vortex of giant waves that went on for more than two days. And the waves had a mean height of 61 feet, and some of the waves were topping 100 feet. And this went on and on, and nothing in the satellite data, nothing in the weather data had predicted conditions like this.

And so at the end, they barely survived the experience. And they had all the data to prove that it had happened. And when this happened, it became clear that so many large ships were going missing, it could be that there were these conditions happening in the ocean that our climate models, our weather models, our best guesses at what's going on, we're not putting the right information into them. We don't understand the ocean at its most ferocious, and here is exhibit A.

DAVIES: Do we know now what causes rogue waves? I mean, is the science understood?

CASEY: Not completely. There is some understanding of why they generate under certain conditions. It's kind of a complicated answer because we do understand in a number of cases why and how, particularly when currents collide or when a storm comes up really fast and the seas become steep. When waves are further away from equilibrium, they have the chance of going what I call sort of haywire. One wave can pirate the energy of other waves around it, and all of a sudden, you have, instead of your typical wave, you have kind of what is, you know, I call a teetering monster, and it's unstable.

And then there were situations that were described to me by scientists that really have them scratching their heads where it just happens. And the scientist who told me about that particular instance, which is true random rogue waves, told me that he believes that the physics that will explain this will come from maybe another discipline, maybe light - physicists that are studying light. There's just something that they can't explain about rogue waves under certain conditions.

DAVIES: You know, a lot of the book is about surfers who seek and find these huge, towering waves in different places. And, you know, you can't catch waves of that speed and energy with a hand paddling, so they've developed these techniques to have a motorized tow of some kind. But can you describe what you heard from these folks about what's the experience like of riding down this speeding, 60-foot wall of water?

CASEY: I spent a long time, you know, watching them and talking to them and being out in those conditions myself. And I tried every way I could. I mean, I think it's a situation where, you know, people might spend 30 years meditating to get to that place. It's just you're entirely present. Every cell in your body is present in that moment. You have to be in order to make it out. And at one point, I even had the chance to go down maybe a 40-foot wave myself on the back of a jet ski. And I understood the cocktail of chemicals that your body pumps out under that condition is pretty intoxicating.

DAVIES: Were you afraid?

CASEY: For a nanosecond. But the thing about fear that I think is so interesting is that when you're truly present, you can't feel it. It's a projection of fear about what might happen or what's going to happen or what happened in the past and you don't want to go through that again. But when you're really truly present, there isn't room for any fear. It's very strange. You can be terrified the second after, but in the moment, you were just in the moment.

DAVIES: Susan Casey, thanks so much for speaking with us.

CASEY: Thank you.

DAVIES: Susan Casey's new book is "Voices In The Ocean." Coming up, Ken Tucker reviews Daniel Romano's new album. This is FRESH AIR. Transcript provided by NPR, Copyright NPR.