"Why do fish jump?" one angler asks another. "Because they don't have fingers," the second angler replies. While this time-worn joke is just that, a joke, it is based, at least to some small degree, on actual observation. This is more than can be said for most, if not all, of the other theories I've heard over the years trying to explain this phenomenon. We'll get back to the observations that provide the genesis for this hackneyed joke in a bit. First, though, let's establish the boundaries of this discussion and debunk a few myths.

I am not talking about why fish jump once they are hooked. I think most of us agree that a chunk of sharp steel lodged unforgivably in the mouth and the resistance provided by a tight fishing line probably offer all of the reason necessary for a fish to jump and fight once it's hooked. From lots of experience over the years I know that getting impaled by a hook is not a pleasant way to spend your time. In actual fact, it isn't getting hooked that hurts so much, at least in my case. What hurts, and can lead to PTHD (Post-Traumatic Hook Disease) is the client yanking repeatedly as hard as they can on a fishing line attatched to a hook that's imbedded in my flesh while exclaiming, "Dennis, it's hung-up! I can't break it free! And my wife wonders why I occasionally wake up in the middle of the night shaking with cold sweats and muttering un-printable curses at people she has never met). There is, as I have been known to point out, a reason we in the guide business refer to it as 'Chuck and Duck'.

I am talking about why otherwise unmolested fish rocket out of the water, for no apparent reason, and then crash, splash or dash back beneath the surface. Often, only to jump again and yet again.

Every angler has probably seen this happen. Over the years on Oregon's north coast, where I live and guide, I have seen thousands of salmon, trout, steelhead and sturgeon jump out of the water for no obvious reason. While guiding in Alaska I have witnessed, in addition to all five Pacific salmon species, as Dolly Varden, pike, grayling and even whitefish do the same. At one time or another over a fishing career that now spans more than forty years I have watched virtually every species of gamefish on the planet do exactly the same thing. From bass to barracuda, from sailfish to sunfish, everywhere I go fish seem to be jumping. I am sure you have seen the same thing.

Here in salmon and steelhead country the two most often cited "scientific" reasons fish jump are either: 1) They are trying to loosen the eggs in their skeins prior to spawning or 2) They are trying to rid themselves of sea-lice. (All three of the local dominant sport fishing species - salmon, steelhead and sturgeon - are anadromous. That is, they are born in freshwater, migrate to the sea as juveniles, reach maturity in the ocean and return to freshwater to spawn. This accounts for terms such as "sea lice" although these small parasites are not limited to the ocean and are commonly found in freshwater rivers and lakes as well). Not only have these two common responses been promoted by otherwise reasonably bright people, many of whom actually work in the fishing industry in one capacity or another and should therefore know better, but they also assume facts not in evidence. Let me explain what I mean.

Based on the reasoning described above every fish that has ever jumped out of the water has to have been either a female preparing to spawn or a fish of either sex infested with parasites. I find it extremely difficult to believe that only female fish, caught in the throes of an ancient urge to procreate, or only fish of either sex, whether ocean-going or landlocked, suffering the inconsequential itch of a parasitic stowaway are prone to jump. Frankly, my credulity just doesn't stretch that far. From lamprey eels, often a foot or more in length, on both ocean-going salmon and landlocked lake trout to barnacles on whales and marlin - often numbering in the hundreds, even thousands - any number of fish species provide a free ride for parasites far more uncomfortable than water-borne "lice".

There is yet a third common explanation for the jumping behavior of many fish. Although based on frustration some anglers, taking the "because they don't have fingers" explanation a step further, will tell you each of those fish is simply jumping out, rolling over and flipping them the fin. While as an angler I agree there are few things quite as frustrating as casting endlessly, with few if any hook-ups, to show for the effort, to fish you know are there because you can see them jumping. I just don't take it personally.

There is also the AFL-CIO hypothesis. I have heard some anglers comment that some species of fish, particularly salmon and steelhead, must be union fish. The reason these 'affliated' fish jump, they reason, is to check the time by the angle of the sun on the horizon to see if their coffee break is over yet. While I must admit this theory, at least at first glance, has possibilities - after all, I at least have never caught a fish that was wearing a timepiece (although I did catch one once that had swallowed a pocketwatch) - upon further investigation I am afraid this otherwise engaging piece of logic simply doesn't hold up to the cold, hard, observable facts. Yes, I know that many fish travel in 'schools' but we have no scientific data indicating that telling time is a subject covered in these schools. Besides, ask yourself this: What about Daylight Saving Time? Huh? How would any fish know, regardless of how far they might have progressed in school, when to 'Jump Forward' or when to 'Fall Back'?

Having deflated the 'spawning female-only', 'parasite-encrusted' , 'no fingers' and 'union organized' explanations for why fish jump, let's return to simple observation for a hint or two concerning why so many species of fish, in so many varied environments, engage in this activity.

In both science and philosophy there is a general rule known as "Occam's Razor". This rule states that an explanation for an unknown phenomena should first be attempted in terms of what is already known about it. Simply put, this means that when all else fails let what you already know about something lead you to an answer relating to something you don't yet have an answer for. Using Occam's Razor as a guideline we arrive at an answer regarding why fish jump that is simple, yet elegant, and deeply satisfying as well.

Have you ever watched from a deer stand or on a nature show as deer frolic? Have you ever seen chimpanzes chase each other just for the joy of it? Have you ever seen bear cubs tumble and rough house? Did you watch as your youngster, in that never-never land between toddler and teen, ran pell-mell at the speed of light playing with friends simply because it felt good? If you have, then you already know why fish jump.

I am convinced that Mother Nature sees to it that every organism above a certain point in the food chain is blessed with enough sense of self to enjoy being what they are. One universal expression of this joy is the exuberance of physical activity. The whole-body rush as adrenaline and endorphins flood the system. The invigorating flush of heat and motion. The stretch and play of supple muscles, the dynamic tension between skin and ligament, bone and tendon as we each discover our physical limits. The range of emotions your face undergoes as you fight a fish leads us to the same conclusion. First surprise, followed in short order by confusion, concentration, determination and finally pride and joy as you bring the fish to net, all point to the same reason.

Fish jump because they can. Because it feels good. It's that simple.

Dennis is a well known veteran professional fishing guide, writer and outdoor skills instructor. He guides in rivers and bays and the ocean along Oregon's north coast for sturgeon, salmon, steelhead and trout and in Alaska for salmon and trout. His popular articles have appeared in a variety of outdoor publications, both national and regional, and on a growing number of respected websites. He is currently working on on a book of humorous stories detailing his experiences as a fishing and hunting guide and a murder mystery featuring a fishing guide as the hero. Go figure. Copyright Dennis Dobson, Oregon Outdoors. Email Dennis at [email protected] or visit his website at http://www.oregonoutdoors.org.