Richard Pyle dives the reef's Twilight Zone

This is the first of two rather extraordinary photographs I'm going to show you today. It was taken 18 years ago. I was 19 years old at the time. I had just returned from one of the deepest dives I'd ever made at that time, -- a little over 200 feet -- and, I had caught this little fish here. It turns out that that particular one was the first live one of that ever taken alive. I'm not just an ichthyologist, I'm a bona fide fish nerd. And to a fish nerd, this is some pretty exciting stuff. And more exciting was the fact that the person who took this photo was a guy named Jack Randall, the greatest living ichthyologist on Earth, the Grand Poobah of fish nerds, if you will. And so, it was really exciting to me to have this moment in time, it really set the course for the rest of my life.

But really the most significant thing, the most profound thing about this picture is that it was taken two days before I was completely paralyzed from the neck down. I made a really stupid kind of mistake that most 19-year-old males do when they think they're immortal, and I got a bad case of the bends, and was paralyzed, and had to be flown back for treatment. I learned two really important things that day. The first thing I learned -- well, I'm mortal, that's a really big one. And the second thing I learned was that I knew, with profound certainty, that this is exactly what I was going to do for the rest of my life. I had to focus all my energies towards going to find new species of things down on deep coral reefs.

Now, when you think of a coral reef, this is what most people think of: all these big, hard, elaborate corals and lots of bright, colorful fishes and things. But, this is really just the tip of the iceberg. If you look at this diagram of a coral reef, we know a lot about that part up near the top, and the reason we know so much about it is scuba divers can very easily go down there and access it.

There is a problem with scuba though, in that it imposes some limitations on how deep you can go, and it turns out that depth is about 200 feet. I'll get into why that is in just a minute. But, the point is that scuba divers generally stay less than 100 feet deep, and very rarely go much below this, at least, not with any kind of sanity. So, to go deeper, most biologists have turned to submersibles. Now, submersibles are great, wonderful things, but if you're going to spend 30,000 dollars a day to use one of these things, and it's capable of going 2,000 feet, you're sure not going to go farting around up here in a couple of hundred feet, you're going to go way, way, way, down deep. So, the bottom line is that almost all research using submersibles has taken place well below 500 feet.

Now, it's pretty obvious at this point that there's this zone here in the middle and that's the zone that really centers around my own personal pursuit of happiness. I want to find out what's in this zone. We know almost nothing about it. Scuba divers can't get there, submarines go right on past it.

It took me a year to learn how to walk again after I had my diving accident in Palau and during that year I spent a lot of time learning about the physics and physiology of diving and figuring out how to overcome these limitations. So, I'm just going to show you a basic idea. We're all breathing air right now. Air is a mixture of oxygen and nitrogen, about 20 percent oxygen. About 80 percent nitrogen is in our lungs. And there's a phenomenon called Henry's Law that says that gases will dissolve into a fluid in proportion to the partial pressures which you're exposing them to. So, basically the gas dissolves into our body. The oxygen is bound by metabolism, we use it for energy. The nitrogen just sort of floats around in our blood and tissues, and that's all fine, that's how we're designed. The problem happens when you start to go underwater.

Now, the deeper you go underwater, the higher the pressure is. If you were to go down to a depth of about 130 feet, which is the recommended limit for most scuba divers, you get this pressure effect. And the effect of that pressure is that you have an increased density of gas molecules in every breath you take. Over time, those gas molecules dissolve into your blood and tissues and start to fill you up. Now, if you were to go down to, say, 300 feet, you don't have five times as many gas molecules in your lungs -- you've got 10 times as many gas molecules in your lungs. And, sure enough, they dissolve into your blood, and into your tissues as well. And of course, if you were to down to where there's 15 times as much -- the deeper you go, the more exacerbating the problem becomes. And the problem, the limitation of diving with air is all those dots in your body -- all the nitrogen and all the oxygen.

There're three basic limitations of scuba diving. The first limitation is the oxygen -- oxygen toxicity. Now, we all know the song: "Love is like oxygen./ You get too much, you get too high./ Not enough, and you're going to die." Well, in the context of diving, you get too much, you die also. You die also because oxygen toxicity can cause a seizure -- makes you convulse underwater, not a good thing to happen underwater. It happens because there's too much concentration of oxygen in your body.

The nitrogen has two problems. One of them is what Jacques Cousteau called "rapture of the deep." It's nitrogen narcosis. It makes you loopy. The deeper you go, the loopier you get. You don't want to drive drunk, you don't want to dive drunk, so that's a real big problem. And of course, the third problem is the one I found out the hard way in Palau, which is the bends. Now the one thing that I forgot to mention, is that to obviate the problem of the nitrogen narcosis -- all of those blue dots in our body -- you remove the nitrogen and you replace it with helium. Now helium's a gas, there're a lot of reasons why helium's good, it's a tiny molecule, it's inert, it doesn't give you narcosis. So that's the basic concept that we use. But, the theory's relatively easy. The tricky part is the implementation.

So, this is how I began, about 15 years ago. I'll admit, it wasn't exactly the smartest of starts, but, you know, you got to start somewhere. At the time, I wasn't the only one who didn't know what I was doing -- almost nobody did. And this rig was actually used for a dive of 300 feet. Over time we got a little bit better at it, and we came up with this really sophisticated-looking rig with four scuba tanks and five regulators and all the right gas mixtures and all that good stuff. And it was fine and dandy, and it allowed us to go down and find new species. This picture was taken 300 feet deep, catching new species of fish. But, the problem was that it didn't allow us much time. For all its bulk and size, it only gave us about 15 minutes at most down at those sorts of depths. We needed more time. There had to be a better way. And, indeed, there is a better way.

In 1994, I was fortunate enough to get access to these prototype closed-circuit rebreathers. Alright, closed-circuit rebreather -- what is it about it that makes it different from scuba, and why is it better? Well, there are three main advantages to a rebreather. One, they're quiet, they don't make any noise. Two, they allow you to stay underwater longer. Three, they allow you to go deeper. How is it that they do that? Well, in order to really understand how they do that you have to take off the hood, and look underneath and see what's going on.

There are three basic systems to a closed- circuit rebreather. The most fundamental of these is called the breathing loop. It's a breathing loop because you breathe off of it, and it's a closed loop, and you breathe the same gas around and around and around. So there's a mouthpiece that you put in your mouth, and there's also a counterlung, or in this case, two counterlungs. Now, the counterlungs aren't high-tech, they're just simply flexible bags. They allow you to mechanically breathe, or mechanically ventilate. When you exhale your breath, it goes in the exhale counterlung: when you inhale a breath, it comes from the inhale counterlung. It's just pure mechanics, allowing you to cycle air through this breathing loop. And, the other component on a breathing loop is the carbon dioxide absorbent canister. Now, as we breathe, we produce carbon dioxide, and that carbon dioxide needs to be scrubbed out of the system. There's a chemical filter in there that pulls the carbon dioxide out of the breathing gas -- so that, when it comes back to us to breathe again, it's safe to breathe again. So that's the breathing loop in a nutshell.

The second main component of a closed-circuit rebreather is the gas system. The primary purpose of the gas system is to provide oxygen, to replenish the oxygen that your body consumes. So the main tank, the main critical thing, is this oxygen gas supply cylinder we have here. But, if we only had an oxygen gas supply cylinder we wouldn't be able to go very deep, because we'd run into oxygen toxicity very, very quickly. So we need another gas, something to dilute the oxygen with. And that, fittingly enough, is called the diluent gas supply. In our applications, we generally put air inside this diluent gas supply, because it's a very cheap and easy source of nitrogen. So that's where we get our nitrogen from. But, if we want to go deeper, of course, we need another gas supply. We need helium, and the helium is what we really need to go deep. And usually we'll have a slightly larger cylinder mounted exterior on the rebreather, like this. And that's what we use to inject, as we start to do our deep dives. We also have a second oxygen cylinder, that's solely as a back-up in case there's a problem with our first oxygen supply we can continue to breathe. And the way you manage all these different gases and all these different gas supplies is this really high-tech, sophisticated gas block up on the front here, where it's easy to reach. It's got all the valves and knobs and things you need to do to inject the right gases at the right time.

Now, normally you don't have to do that because all of it's done automatically for you with the electronics, the third system of a rebreather. The most critical part of a rebreather is the oxygen sensors. You need three of them, so that if one of them goes bad, you know which one it is. You need voting logic. You also have three microprocessors. Any one of those computers can run the entire system, so if you have to lose two of them, there's also back-up power supplies. And of course there're multiple displays, to get the information to the diver. This is the high-tech gadgetry that allows us to do what we do on these kinds of deep dives. And I can talk about it all day -- just ask my wife -- but I want to move on to something that's kind of much more interesting.

I'm going to take you on a deep dive. I'm going to show you what it's like to do one of these dives that we do. We start up here on the boat, and for all this high-tech, expensive equipment, this is still the best way to get in the water -- just pfft! -- flop over the side of the boat. Now, as I showed you in the earlier diagram, these reefs that we dive on start out near the surface and they go almost vertically, completely straight down. So, we drop in the water, and we just sort of go over the edge of this cliff, and then we just start dropping, dropping, dropping. People have asked me, "It must take a long time to get there?" No, it only takes a couple of minutes to get all the way down to three or four hundred feet, which is where we're aiming for. It's kind of like skydiving in slow motion. It's really a very interesting -- you ever see "The Abyss" where Ed Harris, you know, he's sinking down along the side of the wall? That's kind of what it feels like. It's pretty amazing.

Also, when you get down there, you find that the water is very, very clear. It's extremely clear water, because there's hardly any plankton. But, when you turn on your light, you look around at the caves, and all of a sudden you're confronted with a tremendous amount of diversity, much more than anyone used to believe. Now not all of it is new species -- like that fish you see with the white stripe, that's a known species. But, if you look carefully into the cracks and crevices, you'll see little things scurrying all over the place. There's a just-unbelievable diversity. It's not just fish, either. These are crinoids, sponges, black corals. There're some more fishes. And those fishes that you see right now are new species. They're still new species because I had a video camera on this dive instead of my net, so they're still waiting down there for someone to go find them. But this is what it looks like, and this kind of habitat just goes on and on and on for miles. This is Papua, New Guinea.

Now little fishes and invertebrates aren't the only things we see down there. We also see sharks, much more regularly than I would have expected to. And we're not quite sure why. But what I want you to do right now is imagine yourself 400 feet underwater, with all this high-tech gear on your back, you're in a remote reef off Papua, New Guinea, thousands of miles from the nearest recompression chamber, and you're completely surrounded by sharks.

Video: Look at those ... Uh-oh ... uh-oh! I think we have their attention. (Laughter)

Richard Pyle: When you start talking like Donald Duck, there's no situation in the world that can seem tense.

(Laughter)

So, we're down there, and this is at 400 feet -- that's looking straight up, by the way, so you can get a sense of how far away the surface is. And if you're a biologist and you know about sharks, and you want to assess, you know, how much jeopardy am I really in here, there's one question that sort of jumps to the forefront of your mind immediately which is --

Diver 1 (Video): What kind of sharks?

Diver 2: Uh, silvertip sharks.

Diver 1: Oh.

RP: Silvertip sharks -- they're actually three species of sharks here. The silvertips are the one with the white edges on the fin, and there're also gray reef sharks and some hammerheads off in the distance. And yes, it's a little nerve-wracking.

Diver 2 (Video): Hoo! That little guy is frisky! (Laughter)

Now, you've seen video like this on TV a lot, and it's very intimidating, and I think it gives the wrong impression about sharks. Sharks are actually not very dangerous animals and that's why we weren't worried much, why we were joking around down there. More people are killed by pigs, more people are killed by lightning strikes, more people are killed at soccer games in England. There's a lot of other ways you can die. And I'm not making that stuff up. Coconuts! You can get killed by a coconut more likely than killed by a shark. So sharks aren't quite as dangerous as most people make them out to be.

Now, I don't know if any of you get U.S. News and World Report -- I got the recent issue. There's a cover story all about the great explorers of our time. The last article is an article entitled "No New Frontiers." It questions whether or not there really are any new frontiers out there, whether there are any real, true, hardcore discoveries that can still be made. And this is my favorite line from the article. As a fish nerd, I have to laugh, because you know they don't call us fish nerds for nothing -- we actually do get excited about finding a new dorsal spine in a guppy. But, it's much more than that. And, I want to show you a few of the guppies we've found over the years.

This one's -- you know, you can see how ugly it is. Even if you ignore the scientific value of this thing, just look at the monetary value of this thing. A couple of these ended up getting sold through the aquarium trade to Japan, where they sold for 15,000 dollars apiece. That's half-a-million dollars per pound.

Here's another new angelfish we discovered. This one we actually first discovered back in the air days -- the bad old air days, as we used to say -- when we were doing these kind of dives with air. We were at 360 feet. And I remember coming up from one of these deep dives, and I had this fog, and the narcosis takes a little while to, you know, fade away. It's sort of like sobering up. And I had this vague recollection of seeing these yellow fish with a black spot, and I thought, "Aw, damn. I should have caught one. I think that's a new species." And then, eventually, I got around to looking in my bucket. Sure enough, I had caught one -- I just completely forgot that I had caught one. (Laughter) And so this one we decided to give the name Centropyge narcosis to. So that's it's official scientific name, in reference to its deep-dwelling habits.

And this is another neat one. When we first found it, we weren't even sure what family this thing belonged to, so we just called it the Dr. Seuss fish, because it looked like something out of one of those books.

Now, this one's pretty cool. If you go to Papua, New Guinea, and go down 300 feet, you're going to see these big mounds. And this may be kind of hard to see, but they're about -- oh, a couple meters in diameter. If you look closely, you'll see there's a little white fish and gray fish that hangs out near them. Well, it turns out this little white fish builds these giant mounds, one pebble at a time. It's really extraordinary to find something like this. It's not just new species: it's new behavior, it's new ecology it's all kind of new things.

So, what I'm going to show you right now, very quickly, is just a sampling of a few of the new species we've discovered. What's extraordinary about this is not just the sheer number of species we're finding -- although as you can see that's pretty amazing, this is only half of what we've found -- what's extraordinary is how quickly we find them. We're up to seven new species per hour of time we spend at that depth. Now, if you go to an Amazon jungle and fog a tree, you may get a lot of bugs, but for fishes, there's nowhere in the world you can get seven new species per hour of time. Now, we've done some back of the envelope calculations, and we're predicting that there are probably on the order of 2,000 to 2,500 new species in the Indo-Pacific alone. There are only five to six thousand known species. So a very large percentage of what is out there isn't really known. We thought we had a handle on all the reef fish diversity -- evidently not.

And I'm going to just close on a very somber note. At the beginning I told you that I was going to show you two extraordinary photographs. This is the second extraordinary photograph I'm going to show you. This one was taken at the exact moment I was down there filming those sharks. This was taken exactly 300 feet above my head. And the reason this photograph is extraordinary is because it captures a moment in the very last minute of a person's life. Less than 60 seconds after this picture was taken, this guy was dead. When we recovered his body, we figured out what had gone wrong. He had made a very simple mistake. He turned the wrong valve when he filled his cylinder -- he had 80 percent oxygen in his tank when he should have had 40. He had an oxygen toxicity seizure and he drowned.

The reason I show this -- not to put a downer on everything -- but I just want to use it to key off my philosophy of life in general, which is that we all have two goals. The first goal we share with every other living thing on this planet, which is to survive. I call it perpetuation: the survival of the species and survival of ourselves, because they're both about perpetuating the genome. And the second goal, for those of us who have mastered that first goal, is to -- you know, you call it spiritual fulfillment, you can call it financial success, you can call it any number of different things. I call it seeking joy -- this pursuit of happiness. So, I guess my theme on this is this guy lived his life to the fullest, he absolutely did. You have to balance those two goals. If you live your whole life in fear -- I mean, life is a sexually transmitted disease with 100 percent mortality. So, you can't live your life in fear.

(Laughter)

I thought that was an old one.

(Applause)

But, at the same time you don't want to get so focused on rule number two, or goal number two, that you neglect goal number one. Because once you're dead, you really can't enjoy anything after that. I wish you all the best of luck in maintaining that balance in your future endeavors. Thanks.

(Applause)