All right. Can everybody hear me? All right. Very good. Well, welcome to the 2017 annual Montana State University's Library's Trout and Salmonet Lecture. My name is James Thull and I'm the Special Collections Librarian here at MSU. I work primarily with our Trout and Salmonet collections and endeavors. The lecture series is one part of our overall efforts to develop the world's preeminent research collection for all things related to Trout and Salmon. In addition to the lecture series, we house a 13,000-volume collection of books and periodicals, the world's largest. Our home to the archival papers of Craig Matthews, Bud Lilly, George Grant, John Garrock, Dave Hughes, and many more. Again, the world's largest collection of angling-related archival collections. We create in an open-access database housing images of trout angling rivers and salmon from the 16th century through modern times, and have created the most comprehensive and ambitious Angling Oral History Project ever initiated. All oral histories are housed in open-access databases, and an open-access database that anglers, researchers, and conservationists the world over can access for free at any time. Some of the people we have interviewed are here tonight, including Craig and Jackie Matthews, Esther Lilly, and most recently, of course, Jeremy Wade. All right. Others include Lefty Craig, Joan Wolfe, and Ed Engel. We've conducted interviews across the U.S. as well as in Indian Nepal. This coming year, thanks to funding from the Willow Springs Foundation, we'll expand the project to be able to conduct interviews with anglers, fish farmers, conservationists, politicians, artists, and more on every continent where trout and salmon prowl the waters. Our materials are used by the students, faculty, and staff at MSU and researchers of the world over. I encourage everyone here tonight to check out our online materials and come into the Special Collections Library for a tour. I can guarantee you'll be impressed. With the sheer volume and range of materials we hold at your MSU library. And if you come in, I'll even let you experience a unique connection to the history of angling by letting you hold, in your hands, provided their Cheeto barbecue sauce-free book signed by none other than Isaac Walton. So a real true connection to history. So I want to dedicate tonight to the memory of a great friend of mine and a great friend of MSU, Bud Lilly. Bud passed away this past January. Can we get in? Thank you. Bud's list of accomplishments and awards and people he inspired would take more than one evening to cover. I know one of Bud's favorite legacies is the trout and salmon collection here at MSU. The collection, oral history project, and this lecture series that we are all here for tonight would not exist without Bud's vision and his tireless efforts. We at MSU, Citizens of Montana, and Anglers Everywhere owe Bud a debt of thanks. What I'd like to ask now is for Esther, Bud's widow and an angling legend in her own right to please stand up and be acknowledged. So Bud was also a die-hard Packer fan. We always enjoyed talking about the Packers and other teams, and he was a bobcat through and through. So what I'd like to ask everyone here to do for us tonight is in Bud's honor, I'd like to get a go-kats. So can we do give them a nice loud go-kats that'll put a smile on Bud's face wherever he is now? All right. Let's go one, two, three. Go-kats! Thank you everyone. Now it is my pleasure and my honor to introduce Dr. Kathy Whitlock, Professor of Earth Sciences and Director of the Institute on Ecosystems, who will be also introducing our speaker tonight. Thank you for your time. Well, thank you all for coming tonight. This is a real treat. Jeremy Wade, as you know, is a writer and TV host of River Monsters on the Animal Planet channel. And those of you who have watched River Monsters know that Jeremy has a special interest in rivers and freshwater fish and that he's traveled to some of the most remote rivers in the world and he's shared those adventures with the rest of us. Jeremy grew up in Southeast England and he says that his fascination with the underwater began as a kid in Suffolk where he developed a desire to always see what's around the next bend. He earned a degree in zoology from Bristol University and a teaching certificate in biological sciences from the University of Kent. Before his occupation as a TV host, Jeremy worked as a secondary school biology teacher, a tour leader, a motorcycle dispatch writer, a supply teacher, an art tutor, a translator, a public relations consultant, and a newspaper reporter. His first overseas trip was to India in 1982 and this was followed by expeditions to the May Kong, Congo, and Amazon rivers. His 1994 book, Somewhere Down the Crazy River, co-authored with Paul Arthur Boote, tells the story of the perils faced by these two angler adventurers as they rediscover the Indian, Maasier, and the Goliath tiger fish of the Congo. This book is considered to be a classic of the angling literature. Jeremy became a TV personality in 2002, hosting his first show Jungle Hooks, a five-part series set in the Amazon for Discovery Europe. In 2005 this was followed by the series Jungle Hooks India and in 2009 by River Monsters. River Monsters has now completed nine seasons and achieved the largest ever audience in the history of the animal planet channel. In addition to catching fish on his world travelers, Jeremy's had the misfortune of catching malaria, he's been jailed as a suspected spy, he's almost drowned, he survived a plane crash, had a close encounter with an Alaskan bear, and he found himself facing the wrong end of a gun. One can't help but wonder what perils and adventures lie ahead for this gentleman. So please join me in welcoming Jeremy Wade. This is working, you can hear me in the back, can you? Wonderful to see such a great crowd. I was expecting maybe half a dozen people to be able to get a fire-side chat. Obviously I'm very honored to be asked to speak here. To be honest as well, I'm also a little bit surprised because when you look at the art of angling as it is practiced here in Montana, I'm sort of right at the other end of the spectrum. Here you go off to these beautiful jewel-like creatures, and you're using, you know, you're using something like that. I think I can hardly even see it from here. That apparently is a number 16 betis. Is that right? Is it? Number 16 betis. Whereas I tend to fish for these big brown things with teeth and tentacles, and I'm normally using something like that. This is a size 10 hook. It's crimped to 135-pound multi-strand wire. I think I'll swivel there. I've normally got 100-pound monofilament on there. Bait is normally something like, it's normally a lump of dead fish, and I sort of put about anything between four ounces and a pound of weight on there. And instead of doing what you do, I'm not skillfully presenting my offering to the likely lies. I just chuck it out, and I just sit back and wait. Montana also, of course, is synonymous with sublime angling literature. Whereas I come from the sort of the noisy, shouty end of the TV, of the entertainment spectrum. I've even got my own catchphrase, and you don't get any tackier than that. So what could I possibly have to say that might be of interest here? Well, as anglers know, you have the surface of things, and then you have what goes on beneath the surface. And that's a reality, and below the noisy surface of the TV program that I present, the distracting flashy ripple, there's another level of content which we smuggle in there, and which many viewers tap into. It's a celebration of fish, the places where they live, and much more. Perhaps there's something from these deeper depths that I could fish up and talk about. But then I had another thought. This could be a good time and a good place to make a public apology. The first thing I should apologize for is this talk does have a very long preamble. But when we do finally get to the subject, the health of the world's rivers, you'll see why the preamble was necessary, because it explains why I came to choose this topic. I could also very quickly, while I'm here, apologize for that catchphrase, although it is off topic. But if I explain why I do that... See, it's so popular that it's not... I don't even have to say what it is. Anyway, if I explain this catchphrase thing, it might make you more likely to see me as a serious person with a serious message. So while I publicly cringe with embarrassment, somebody please quote my catchphrase to me, or even yell it out if you like. Anyway, fish on. The reason I do that, of course, is partly to inject some drama into the occasion. But more functionally, it is to wake the cameraman up. If you can imagine, we've been sitting there for hours and hours, and everybody's attention is wandering, apart from mine, of course. And even with my super heavy gear, I do actually like to sit there with a finger on the line, because it's amazing what you can feel coming up the line.  And sometimes you get a very gentle, early warning before a take. But the thing is, when that take comes, we want to get that moment on camera. Now, some of you might be scratching your heads now. I can't see any physical scratching of heads, but some of you might be a bit puzzled, because how can the camera record something that happened before the cameraman woke up? The answer is this magical feature called pre-roll. The camera is always rolling, but instead of storing everything, all those hours of nothing happening, which some poor editor has got to go through, it only holds on to the last seven seconds in a temporary cache. Hit the record button, and in effect you reach back in time, and those seven seconds are front loaded onto your clip. This does have its downside. Somebody might say something about somebody back in the production office, and suddenly we're all silently counting.  You've also got to be careful what you do. Locked away in this secret cupboard somewhere, there's footage of me and the cameras behind me, but in my right hand I've got this screaming rod, and let's just say I'm multitasking. Anyway, so that's my catchphrase, apology even. But what's the big thing that I want to apologize for? Well, it has been said that I make people unnecessarily scared of what's in the water, that I paint a picture of a dystopian world where all the finned creatures have got it in for the human race, and given half a chance they'll employ whatever means they have at their disposal to inflict pain or death, preferably both, on any unfortunate biped that comes their way. If they're too small to bite off a limb, not equipped to stand or electrocute, they'll swim up an orifice and devour us from the inside. Well, that can be the impression from a distracted viewing of the show, but anyone properly paying attention will not come to this conclusion. The death or injury incidents that we report, and we lovingly reconstruct them in vivid gurgling technicality, because this is TV after all, are for the most part extremely rare.  But more correctly, it's not really about luck. It's about being in the wrong place at the wrong time. And that's something you can largely avoid by being aware of what's living in the water and the behaviour of those creatures. In other words, a so-called attack by a fish is not normally the fish's fault, but the fault of the human victim for going too close to a snakehead's young, for standing on a stingray, or for cooling off in an unfamiliar river without bothering to ask or wonder why nobody else is in the water. This is why, when I catch a potentially dangerous fish, like a 10-foot bull shark up a small river in South Africa, as I did once, I don't beat it to death, but I put it back into the water. Any danger is almost all down to the human behaviour, not fish behaviour. And intelligent viewers seem to get that without us laboring the point. I think I've heard about free emails in nine years. Why do you put those fish back in the water? Most people get it. I do accept, though, that the programmes are very much about fear, and that's what helps us to hook viewers, because we've all been programmed by generations upon generations of natural selection to pay attention to things out there in the environment that could harm us. For most of human history, that meant predators. Cavemen who didn't pay attention to saber-toothed tigers didn't leave descendants. So this fascination with predators is genetically hard-wired into us. But playing to that fascination is not gratuitous. There's an important lesson here. Keeping ourselves safe is about being vigilant and understanding what's out there. And that applies to anything that could hurt us. We all live in very close proximity with speeding automobiles, for example. But we know how to cross the road without getting hit. It's the same principle with toothy fish. So I'm not apologising for demonising fish, because I don't do that. Having said that, there was that time when I said that salmon could be possible man killers. I don't know if you saw that episode. Surely that was stretching things a little bit too far. This was in an episode set in Alaska. And I was talking about a hypothetical set of very specific circumstances. Somebody is wading on the edge of powerful flow. A big fish takes. The fisherman stumbles on a slippery rock. Cold water starts to fill up his waders. The next thing he knows, he's being swept away downstream and slowly sinking under. Now, there's an obvious way to avoid this ending badly, and I can imagine all the non-anglers shouting at their TV sets. But to anglers, it all makes perfect sense, because the one thing we all know, which they told me in Alaska, and which I know from personal experience, is we're never going to let go of that rod, are we? So I'm not apologising for hypothetical killer salmon. What I feel compelled to apologise for is something much more serious. What I do in my programmes is portray a false reality. Not in the way that many people might think when watching a so-called reality show.  But something much wider than this.  If you watch the programmes I make, you'll get the impression that pretty much every river that you go to, particularly in wilder parts of the world, you're going to find fish capable of biting your leg off or dragging you under. Okay, that's a slight exaggeration, but you're going to find large predatory fish. This couldn't be further from the truth. Most places you go, if you were just going to stick a pin in the map at random and travel at random, you're not going to find anything. To make sure that I have a realistic chance of getting a result in the course of a three-week shoot, during which I have a maximum of 11 days fishing, but it's more commonly just four or five, we have to do our research very thoroughly indeed. Because without a fish, we don't have a programme, and that really concentrates the mind. If I kept going to different exotic places and catching nothing, nobody would watch and I'd be out of a job. So I'm extremely selective about where I go. So finding big fish is hard. Is that all I'm saying? Every angler knows that. There are fewer medium-sized fish than there are small fish. There are even fewer big fish than medium-sized fish. But it's not just big fish being hard to find that I'm talking about. What I'm talking about is how they are much, much rarer now than they were in the past. Not the ancient past, but the very recent past. Fish have been around on this planet for about 530 million years. The decline I'm talking about has happened in just the last hundred years or so. In terms of the planet's lifetime, that's barely the blink of an eye. How do I know this? Because my research involves digging out historical reports and talking to the people who live on the river, asking them about how things are now and how they remember them in the past. It's a very patchy record. It's anecdotal and not very scientific. But the picture that emerges is clear and alarming. These are large animals, some of them larger than people, and they're disappearing before our eyes.  They're mostly invisible, and their disappearance is invisible. So there's no publicity. There are no campaigns to save them from whales, tigers, sea turtles. There's just a fragmented oral database, mostly unheard in the form of old people's memories, which cover a period more or less of this decline. But when the old fishermen pass away with their oral histories undocumented, there will be no meaningful record of how the world's rivers were before the fish went missing. And in the absence of earlier data, we end up taking the way things are now as baseline as normal. It's what's known as baseline shift. And its effect is to normalize the abnormal. Let me do a quick global roundup of how much things have shifted in this short time period that I'm talking about. My first trip after exotic fish was in 1982, as you heard a little earlier, to India. In India, the iconic river fish is the marcia. Now, I once got a clicker picture of marcia. So there we go. That's a marcia. There are two main species of marcia. The humpback marcia in the south, this is a humpback marcia, and there is the Himalayan or golden marcia in the north, which is more streamlined in shape. The marcia is a member of the carp family, characterized by its coat of large gleaming scales. Is there a weird effect going on when I get close to that microphone? Can I just keep away from that microphone? Or just do something? Maybe I'll just... There we go. Is that better? Right. So as a member of the carp family, large gleaming scales, powerful prehensile mouth, and its ability to live in raging white water. And although it might not look like it, it's a very effective predator. It does have teeth, but they're at the back of the throat. There's a lot of literature about marcia, written by British colonial officials who lived in India pre-independence in the early 1900s. The special collection here that you've been hearing about at MSU has a number of these volumes, including H.S. Thomas' classic, The Rod in India. These authors tell many tales of expensive salmon gear getting smashed up by unseen giants, but they also landed a lot and photographed their catches. Today, such catches are unimaginable. In most places that were written about, you'd be lucky to catch anything at all. By the time I went to India, big fish were confined to just a few last strongholds. I managed to catch this 58-pounder. I had another one of 66, another one of 92. But now, 30 years on from that, your chance of anything over 50 is practically zero. Apparently, I do need that there. I'm not a technical person.  I don't understand any of this stuff. How's that? Is that better? Is that good? Yeah, I think we are good. Okay. North Indian rivers are also home to the hideous Goonch catfish. Let's see if I can get this right. There it is. Goonch is the pronunciation. And there it is. And what a hideous thing. The fish is pretty ugly too. These were despised by the colonial colonels. And one writer described them as the vermin of the water. Nowadays though, you'd be very lucky to even hook one. A better description now would be the underwater yeti. Next, I went to Thailand looking for the Mekong giant catfish. This was the time I was arrested as a suspected spy for poking around where the river forms the border with Laos armed with a camera and notebook. Under interrogation, I told them that the reason I had travelled thousands of miles to this place was to try to catch a fish, which I was then going to put back. For some reason, they didn't believe this. They decided it was an elaborate cover story for something else and confiscated all my film. After they released me, I managed to lose my police escort and I made for the British Embassy in Bangkok where they told me to leave the country as soon as possible. In my film canisters were undeveloped pictures of what at the time was by far the biggest fish that I had ever seen. Longer than my outstretched arms and unbelievably deep-bodied, apparently with no eyes until I located them near the corner of the jaw, I'd found my Mekong catfish. Alive, I guess that fish would have weighed about 200 pounds, but this was just the stuffed shell of a fish, moth eaten and covered in dust. The Mekong giant catfish is unusual because it's not a predator or it's a herb before. They were once plentiful in the Mekong River, but hardly any are caught there now, a mere handful each year and they're never caught on a line or not on the Mekong anyway. You do find pockets of them in captivity though. This is a sort of captive fish. Commercial fishing lakes, which serve as unofficial aquatic wildlife reserves, but because of their rarity in the wild, they're listed now as critically endangered. In Africa, there's the Goliath tigerfish. I first read about this fish in a book chapter written by a Belgian doctor in the 1940s. He caught them up to 87.5 pounds and lost many more because these bony mouth creatures are masters of spitting the hook. Including one, he lost one that he put at 200 pounds. Since then, infrastructure in the Congo has crumbled away almost to zero. Time in many respects has moved backwards in this part of the world. So you'd think this is one fish population that is still at true baseline levels. Not so. It took me three expeditions over six years to catch my first Goliath tigerfish. And when we took the gamble to make an episode about them, we caught that fish two weeks for four takes and landed just this one. So even in one of the world's most inaccessible jungles, the picture is of undeniable decline. In South America, the iconic freshwater predator is the Arabima. When you talk about the Amazon River, you're talking about a very dynamic and changeable thing. In some places, the water rises and falls by as much as 50 feet. 50 feet, twice the height of this room, over the course of a year. For half the year, huge expanses of forest are semi-submerged and fish swim through the trees. Then as the water drains, it leaves a multitude of flood plain lakes of all shapes and sizes, some of which become very shallow and de-oxygenated. This is where the Arabima used to rule. Because they can extract oxygen from the air, they gulp at the surface. They're actively hunting when other fish are going barely up. So as long as there are small fish to eat, you can get very high densities of big Arabima in small volumes of water, limited by their need for territory, personal space, rather than oxygenation. Many fishermen have told me of seeing Arabima surfacing one after another in places where now you won't see a single one. In the moving water of the Amazon, the river channels, the top fish is, or was, the Paraiba catfish. This is, although it's a catfish, this is not a slow-moving scavenger, but a streamlined beast in some ways reminiscent of a shark. And it's the same story. Fish of any size are very rare now, from just a few very selective, very select parts of their former range. What about North America? For me, the fish here that most absolutely fits the description of River Monster is the alligator gullop. This is another air gullopper, and it used to be found in the Mississippi as far as St. Louis, way up the Ohio, up the Illinois, the Missouri as far as Kansas City, and much of the Arkansas system. Now it's pretty much confined to Texas, Louisiana, and a corner of Mississippi. Meanwhile in Europe, where I come from, we have our own giant river fish, the Wells catfish, also known as the Danubian catfish, because the River Danube is its historical home. But when I went to the Danube Delta in Romania about 15 years ago, I caught just a couple of baby ones, about this kind of size, a few pounds each. I've recently heard there's a place upstream where you might catch a 50-pounder, but that's still small when compared with how big they can grow. If you want to catch a big one now, you've got to target the introduced population in the real Ebro and Segre in Spain or the Poe in Italy. But forget the Danube for Danubian catfish. It's a similar story with Nile Perch, sturgeon species around the world, Chinese paddlefish, the list goes on. Building a global picture that's pretty clear, one of dramatically shrunk ranges and the big fish much rarer. But what does it matter if the big fish are disappearing beyond making things hard for me? You heard earlier that I used to be a biology teacher and that's still there in the background. It wasn't until just the last few years that the wider significance of this started to sink in. The fish that I go for are mostly apex predators. That is to say they're at the top of the food chain or more correctly at the apex of the food pyramid. And as any Egyptian architect will tell you, you can't have an apex without having the supporting structure underneath it. What this means is that there are two ways to check for the presence of a healthy food pyramid. You can either sample for all the individual components of the food pyramid, all the fish species, all the crustaceans, the mollusks and the insects, the plants and algae, or you can take a shortcut, sample for the apex predator. In a river, the presence of the apex predator is a great indicator of the health of the river as a whole. So what does the increasing absence of apex predators tell us? It would seem to tell us that the world's rivers are in a bad way. It has been said many times that rivers are the arteries of our planet. It's a nice poetic analogy to the point of being a cliche and we normally leave it there. But let's dig a little deeper into this. If rivers are the earth's lifeblood, that makes me a kind of doctor or phlebotomist because what I've been doing for the last 35 years now is taking the planet's blood samples. Let's pursue this analogy a little further. Imagine you just had a blood test and suppose that came back with an abnormal result, something like an abnormally low white cell count. What would be your reaction? Would you just shrug and disregard it? I'm guessing that wouldn't be your reaction. First, that'd be a mixture of shock and disbelief because you would look fine and you feel fine. Then you might ask to be tested again to make sure there wasn't some mistake or mix-up with the samples. Then when it came back saying the same thing, you'd want more information.  Is it the early warning of something terrible? What caused it and can anything be done? You don't just cover your ears and hum. This should explain why I feel a growing sense of responsibility to pass on what I've heard and seen. Much of the complacency about our planet's health is down to shortage of information which in our so-called age of information is supremely ironic. What I've been telling you this evening is my attempt to address that information deficit. But let's not leave it there. Let's imagine for a moment that we decide to take these planetary blood test results as seriously as we take a personal health scare. How did it happen? What does it mean? Can we do anything about it? This is where I start to leave my area of expertise. But given the shortage of other information out there, let me fumble towards some answers. As to why these apex predators have gone missing, leaving just the crumbling ruins of the biological pyramids that once supported them, the obvious explanation is overfishing. That's harvesting at a rate that cannot be replaced. And from what I've seen, overfishing is certainly a big factor. Although freshwater fish don't feature as a huge part of the diet in Europe and North America, in other parts of the world, it's a different story. In the Amazon, eating fish is always used to make sense, given the amount of water and the small numbers of people. For a long time, aropima were left alone. What's the point of trying to catch one if you don't have a refrigerator unless you can eat 120 pounds at a sitting? But then came the Portuguese colonists with their tradition of eating salted cod. In the absence of cod, aropima became cod substitutes and a major cash crop for river dwellers. Every family would accumulate a stash of fillets like man-sized kippers, which they sold to travelling middlemen. The original way to catch aropima was with a harpoon, with a breakaway shaft and a strong cord attached to the head. This sounds like a very unproductive way to hunt fish. And it would be where it not for the aropimers' need to come to the surface every half hour or so to gulp air. Its secret weapon was now its Achilles' heel. But a harpoon becomes ineffective when the fish numbers start to fall, and the aropima population might have stabilised as a lower level had it not been for the arrival of nets. I've seen firsthand how teams of fishermen net aropima. If a lake is landlocked, they will drag and carry their canoes through the forest, sometimes a couple of miles. They will wait until they see a big fish surface and then in stealth mode, gradually pen it in. Eventually, they will try and make it bolt into the net. The fish are still no pushover. If they've been targeted before, they can show uncanny powers of evasion. I've seen them jump over a net. They can slip underneath if the fishermen have not made sure that it hangs cleanly all the way to the bottom. On one occasion, I witnessed a tiny bob of the net float, which signalled a fish inserting its snout into the mesh, then expanding its head to break a hole for its body to slip through. That fish deserved to live. But the fishermen are very highly motivated, and having seen them in action, I now understand why aropima have become almost non-existent in much of the Amazon. Cheap monofilament nets and the availability of ice have also allowed the large-scale harvesting of other Amazonian species. There's now a huge commercial fishing operation operating out of Manaus, the city of 2 million inhabitants at the heart of the Amazon, which was originally the global HQ of the rubber trade before becoming an industrial free trade zone to keep the Brazilian Amazon populated after the rubber boom ended. Not exactly most people's mental picture of the Amazon. And if there's overfishing in the Amazon, imagine the problems elsewhere. The demand for protein in India, for example, is so intense that some people fish with dynamite and insecticide. And yet there's something almost comforting about overfishing. If that's all it is, then it's all right. It's anemia, not cancer. It's reversible, we think. But there could be other factors at play. There is now growing awareness that dams can block breeding migrations and can alter a river's flow in other ways that have an impact on fish. Breeding can also be hit by the apparent effects of climate change. Most rivers have an annual cycle of high and low water, which varies somewhat from year to year in timing and levels, but it's broadly predictable. Fishermen whose livelihoods depend on the river watch this cycle more closely than any scientist and in places where no scientists ever go. And what they've been telling me, my success or failure in catching my target fish also depends very much on timing, is that these water cycles have been getting increasingly unpredictable. For example, I went fishing in the creeks off the quarantine river in Suriname and found the aggressive annumara, also known as the wolffish, far harder to catch than I'd anticipated.  Last week, if anything, would have been even harder. It had been raining at a time of year when normally it never did. So low water was two feet above what it was normally with the result that the fish were spread far into the forest rather than being concentrated in the creek mouths. In Guyana, I saw turtle eggs being uncovered then washed away from their nests in the sandbars when the water, which had been well into its annual fall, started to rise again prematurely. In the far east of Russia, I arrived on the Amur River to find huge numbers of floating dead salmon. Nothing unusual about that, except these were still full of eggs. A heat wave, unlike anything in living memory, had raised the temperature of the river water and they basically cooked to death. Here's something more shocking. These physical changes that fishermen worldwide have been telling me about have taken place not over the last century, but over just the last 15 years or so. There's one other possible factor which fits more closely with our 100-year time scale. And this is something that's rather dropped off the public radar. That thing is pollution, contamination of the water by two categories of human waste, sewage and chemicals. Pollution is the dirty secret of our shiny industrial age. While the rhetoric we hear is all about competition, innovation, efficiency and the discipline of the market, the reality is that in too many cases profits are generated by dumping some of the costs on an unknowing public. In less prosperous countries, water pollution can be very evident if you happen to be near its source.  Sometimes the effects of pollution are very obvious. Last year, a slurry from a farm was released into my small local river in the UK and the result was hundreds of dead fish floating on the surface. A couple of months ago, in Asia, I saw an animal that was being skinned alive by chemicals in the mud where it wallowed. Meanwhile, downstream, people collected that water for drinking. But normally pollution is invisible which helps to explain why so many of us are complacent about it. So those are my four suspects for the chronic bad health of our rivers. Overfishing, dams, climate change and pollution. How, if at all, do these affect us and can anything be done? With overfishing, the answer has to lie partly with tougher regulations. In the oceans, it's estimated by the UN Environment Programme that there will be no commercially viable seafood by 2050 if nothing is done. Imagine that. If that's the prognosis for the immensity of the oceans, surely rivers which comprise less than 0.01% of total water are doomed. Or maybe not. Unlike the oceans where things are largely free for all, in rivers there is a far clearer jurisdiction. And there are some success stories where the trajectory has been reversed. Like the recovery, for example, of the white sturgeon population in the lower Columbia River. It's probably time we also took some personal responsibility and looked at fish consumption. Wild fish are now a luxury item. We should try to eat only fish that come from sustainable sources. Of course, aquaculture could be part of the answer as long as environmental harm doesn't cancel out any of the benefits. Recreational fishing also has a part to play. I am somewhat uncomfortable about the beaches of river in poorer nations being protected in order to become playgrounds for rich foreigners but this can bring some real local benefit. And in developed nations, catch and release angling demonstrably helps to keep our rivers healthy and beautiful. For proof of that, just look at Montana. What about dams? In our innocence, hydroelectric power was such a beautiful idea. Free, clean energy thanks to the sun and gravity. But it turns out nothing's free. There are costs to be weighed. Fish such as salmon, sturgeon and eels find their migration routes blocked. Now that we have a fuller understanding some steps are being taken to make dams that are more fish friendly and to retrofit existing dams with fish ladders. But if migratory fish are disappearing don't leave it too long to restock. It turns out that with some fish knowing where to go when they get the urge to migrate it's not totally innate. It's something they learn from other fish. If there are no older fish around to show them the way they won't know what to do when the time comes. What to do about climate change is the subject for a whole other talk. What much of the world seems to be doing right now is hoping that the effects will all land on somebody else. Like the Greenlanders I stayed with last year who are having to shoot their sled dogs because the sea ice is fast disappearing. But if you start to consider for example the global ramifications of say the civil war in Syria which was preceded by the country's worst drought in 900 years then the head in the sand approach doesn't make an awful lot of sense. We seem to be equally complacent about pollution. In more prosperous developed countries we have the comforting belief that effluence are kept to safe levels safe for fish and safe for us. But who decides how much of a pollutant is safe? Is there a consensus? This takes us into another big subject. Even in so called democracies the amount of contaminants that are present in water is largely determined by the people who put them there people with a vested interest in business as usual.  And although it's easy to point the finger at dirty industries, large swathes of the public collude in this process by buying into the belief that regulation is always a dirty word and the almost religious belief that ever increasing levels of consumption and hence waste production is the only way to avoid economic doom. There's also something else working here operating at a deep mental level that hit me with particular force a couple of months ago. I was in a car driving through a city in Asia and out the window I saw this huge expanse of trash and it just went on and on in the form of a strip maybe 30 feet wide for a couple of miles and the thing was it was right in front of people's houses and I knew that if I was to go into any of those houses I would be expected to remove my shoes and I would find people who prided themselves on their cleanliness and as I stared transfixed at this river of trash I realized what a disconnect there now is in the world between private space and public space you don't always see it so dramatically but it's always there the mental boundary between us and the world out there perhaps we erect this barrier because it's the only way we can deal with the increasing complexity of the world it enables us to think not to think about the world too much about the air, the soil, the rivers about our effect on them and their effect on us we tell ourselves there's nothing much to do with us but rivers are everything to do with us even those of us who don't fish we think of rivers as channels bounded by their banks but this is a limitation imposed by language in reality they are boundless and they circulate by multiple channels not just the textbook one down to the sea then up into the atmosphere where vapor becomes rain and snow they also flow through us as deep as it is possible to go across every cell membrane into every cell into every nucleus of every cell where the delicate chemistry that controls our bodies takes place and if you think about this it gets quite scary now we've suddenly jumped from abstract environmental stuff to personal mortality because what happens when the delicate chemistry of cell division goes wrong what happens is the class of diseases that is becoming stubbornly more prevalent worldwide which will affect one in three women one in two men in the US a friend of mine from university days who now works in cancer research once said to me we know what causes cancer it's all the chemicals we put into the environment this of course is an oversimplification there are other factors too but the chemical intruders in our deep internal waterscape which have never been there before have to be of concern to any thinking person people often ask me if I'm scared of the fish that I catch and the answer is yes but if I pay attention and take the trouble to understand the fish we can both come away from the encounter unscathed what scares me is the stuff in the water that you can't see and the fact that what it can do to us is not fully understood and the fact that people keep unthinkingly putting it there anyway the trouble is it's impossible to prove that a specific molecule or a pollutant from a specific source caused a specific harmful effect in a specific body cell in a specific person there's no smoking gun my fear is just a gut feeling but just last week in a trawl of scientific literature I came across some fascinating circumstantial evidence an epidemiological study by Hit and Hendricks in 2010 found a correlation between the ecological impairment of streams as measured by a number of indicators not just what I've been doing the apex predator correlation between that and human mortality rates in the surrounding areas from certain cancers this appears to confirm that we are as dependent on healthy river water as any fish for this reason disappearing river fish should be of the utmost concern to us all in particular avoidable pollution of river water should be seen for what it is not an inevitable by-product of economic progress but a personal affront to every one of us I think the fish are telling us something the question is will we listen thank you