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March 16th, 2009
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FINDING THEM: The bottom line to all of the information in this paragraph is that fly fishing for bass is most successful (1) in the shallows (2) during the spring and fall. There are good reasons for this. Not all of any lake has identical scientific properties and conditions almost always differ from one area to another. Bass follow optimal conditions around a lake. Many variables are involved, most importantly: pH, Oxygen (O2), and temperature. The pH is a measure of acidity or alkalinity. The pH scale runs from 0 to 14, with 7 considered neutral; anything lower than 7 is acidic and anything higher than 7 is alkaline (or basic). Bass have blood that is slightly alkaline (7.6), but can survive in water with a pH ranging from 6.7 to 9.6. At the same time a bass can survive oxygen levels from 5 to 13 parts per million (ppm) and that is where they will be. Bass are cold blooded, which means that they reflect the temperature of their surroundings and they rely on their environment to provide comfortable conditions. Weather extremes reduce O2 levels, making bass lethargic, they become practically comatose below 50 degrees and similarly inactive above 90 degrees. Largemouth bass prefer warm (not hot) water and spawning begins around 60-70 degrees. Bass thrive in 80 degrees (adult) to 84 degrees (juvenile). In these waters O2 is plentiful and bass are aggressive. All of which just goes to prove that bass are not everywhere in a lake, and even if you know where they are, they may not stay at that location. Because bass are sensitive to these variables, possibly as much as 50-60 percent of your favorite lake is unsuitable as bass habitat at any given time which may be why you never caught one in that "fishy" looking spot. During the spawn they are generally found in shallow flats. As the spawn winds down, bass move into deep water, where they spend the dog days of summer. For many lakes, deep means deeper than a fly rod can fish. Both summer and winter bass usually hover at the thermocline (where water temperature changes subsurface) because it provides them with the best temperature for more oxygen, but there are a few bass which will always remain in the shallow flats areas (mostly juveniles) and around vegetation. Fishermen mistakenly think weeds and vegetation are simply ambush spots (which they are), but the truth is also that vegetation on the surface can absorb heat and transmit it to the water, consequently the shade under weeds may actually be warmer than surrounding waters and in cool weather is inviting to bass for that reason. On hotter days, water under vegetation may be unsuitably hot. Consequently, finding fly rod accessible bass is a matter of anticipating shallow water temperatures. When summer water temperatures cool, bass return to shallow-waters where they will feed before moving again to the deep water for the winter and when winter temperatures abate they return to the warm shallows to spawn. For this reason, the fly fisherman should concentrate on spring and fall. WHAT BASS EAT. For the fly fisherman, the critical components of a bass' diet are fish, insects, crawfish, and occasional special meals such as frogs, lizards, ducks and mice. Bass like big meals, and, given the choice, will opt for a large victim, even one that barely fits in its mouth. Essentially, no fly is too big. Consider that the largest fly it is feasible to cast on a 6-7 weight outfit will be small compared to something like a crankbait or buzzbait. On a sunny day at the local airport I stood on a small bridge and watched several dozen bream and a couple of healthy bass swim through the shadows. There were the bass, surrounded by easy to catch meals in a confined space, and they did little more than nudge the bream aside as they swam through. Until that time I considered bass a killing machine, gorging constantly. I have come to learn that bass use two clues to feed: (1) when they are hungry, and (2) when environmental conditions tell them to. If either of these is missing, they don't feed and bass conserve energy and prefer to move as little a possible to get a meal. As the time passed and I waited on the bridge, one of the larger hand-sized bream swam in front of and slightly above one of the bass. With a movement so quick I wasn't sure of what I saw, the bass snapped it's head up and to the side and the bream disappeared presumably in the bass. It was a big meal a bluegill in the wrong place, wrong time. [Bass eat plenty of sunfish, but, given the choice, will eat more streamlined easily swallowed fish shad, small bass instead. However, if a bass has never seen a shad, it will feed first on a familiar prey.]
WHAT BASS SEE BASS VISION AND FLY COLOR: Because of their field of vision, bass predominantly attack upwards. Like other predator fish species, bass have good vision 180 degrees for each eye. This allows them binocular vision in front and up where the 180 degrees of the eyes overlap. There is a small blind spot directly between the eyes and a large one from the side fins back and under the belly. In other respects, bass vision is complicated to explain. They can focus well at various distances. Because their lenses are spherical, this enables them to see underwater because there is what is called a higher refractive index to help them focus, which they do by moving the lens in and out. They can also see under various light conditions. A basses lens bulges through the iris so their pupils do not dilate or contract but they have a special pigment that shields the eye from bright light and structures which amplify the incoming light allowing for good vision in low visibility conditions. Consequently, it can be assumed that bass get a pretty good look at their prey.
![]() MASK HUMAN SCENTS: The sense of smell (chemoreception) is very well developed in bass, which rely upon this sense to detect prey, to avoid harmful PH conditions or harmful chemicals, and to find suitable oxygen content. Largemouth bass have paired nostrils (nares) on each side of their head between the eyes and upper lip. The olfactory rosette (epithelium), consists of complex folds that line the nostrils. Within the epithelium, odor activates olfactory receptor nerve cells. Older bass have a larger number of olfactory folds with a larger diameter. Consequently, older bass can smell better and can detect odors 20-30 feet away that are equivalent to a few parts per million in the water. Using fish attractants and scents is not commonly associated with fly fishing, but there are reasons to consider making limited use of them. Primarily, attractants mask human scents that are repulsive to bass. A fly that smells like human sweat, sunscreen, cologne, tobacco, beer, gasoline or head cement may not be effective for just that reason. But while spraying a fly with attractant seems sacrilegious, a simple solution is to apply fish attractant to your hands then handle the fly. The downside is that fish attractant is usually oily, making many fishing tasks more difficult. [Make-your-own scent options usually involve baby oil and anise, or WD40.] Many attractants use some form of anise (licorice) as the primary masking agent. Non-oily anise is available in liquid form on food seasoning aisles and a drop rubbed on your fingers will usually suffice to mask offensive smells. Picking up and tying on the fly should transfer enough anise to the fly to do the job without affecting performance. DELIVERING THE FLY: Because it's important, it bears repeating: bass don't move around unless they have to because of environmental conditions or instinct (e.g. spawning). Usually, catching bass means working a fly near the bass. Anywhere in the line of vision has potential, but six inches takes less work on the bass' part than six feet. As opposed to many species, a delicate delivery is not required. Mice falling into the water panic, baby ducks swimming by have quickly paddling webbed feet, frogs have an elongated moving profile as they swim, an injured fish will thrash or jerk or move erratically, and all of these make ripples, vibrations or splashes. A fly splashing onto the water signals to a bass that something has fallen in, not that something is out to get her. Remember that fishing birds are either greatly patient and statuesque, or dive bombers that only splash an instant before eating. If a bass hears a splash and has not been eaten, it considers the source food. Bass have ears located behind the gill plate together with a lateral line system. A bass' ears are divided into an upper section (that gives the bass its sense of balance) and a lower section that translates vibrations felt by the bones and tissues surrounding the ear into sound. Most important, however, is the lateral line system. Within the lateral line are sensory structures (neuromasts) and each neuromast contains hairs covered by a gelatinous cupula which is the component that extends into the lateral line canal where it is exposed to water. Vibration in the water causes the cupulae and enclosed hairs to bend allowing a bass to precisely determine the direction of the vibration source. In this way bass can identify the presence of prey (perhaps even distinguish species) at considerable distance. WORKING THE FLY: In nature, creatures do not perform synchronized swimming. Movements of prey are often erratic, sometimes panicked, and frequently unpredictable. For this reason, the movement of a fly should not be consistent or unchanging. It is easy to fall into a lazy cycle where every movement of a single retrieve is identical and every retrieve is like every other. Stupid fish can be caught this way, but smart fish live longer and get bigger. Bass baits should make noise and resemble something scared or hurt. Mice have tiny legs not made for swimming. A mouse in the water is practically helpless and knows it, and shows it with a flurry of movement toward the nearest cover. Hence, a mouse fly should be retrieved with a lot of racket but not too rapidly and toward cover, not open water. Large bugs freak when they hit the water, then are exhausted quickly, then freak again. This is best reflected in the strip-pause-strip-pause retrieve. Frogs are used to the water but don't like spending time in open waters. The best retrieve for a frog fly is strip-strip-strip all the way and fairly fast. Minnows are most appealing to bass when they are injured. Minnow replicas should get a strip-strip-pause type of approach causing the bait to move through the water in spurts then fall as an injured fish might. Expect the strike on the fall. Smaller insect replicas should be retrieved very slowly unless the bait is a dragonfly nymph (which jets through the water in short spurts). Small bugs do not move fast through the water even with a lot of effort and generally go where any movement of the water sends them. If it happens to bring them near a hungry bass, well, not all luck is good. CRAWFISH: Crawfish get their own heading here because there are almost no hard and fast rules for fishing crawfish flies. Yes, biologists have found that crawfish (particularly young crawfish) are a common food for bass. Actually, some studies indicate that where crawfish are prevalent, they may compose 75 percent of a bass' diet. Why? Because when they are around there are a lot of them, they are high in protein (instinct tells bass it is good for them) and they are easy to catch (bass don't have to spend energy finding them). The average lifespan for crawfish is one to two years and they produce young in every season but winter (sometimes then in warm winters). With thousands of small crawfish readily available, bass will still take the big meal large crawfish if it is available. (Consider the effectiveness of the "jig and pig" traditional bait, a huge crawfish replica offering that consistently takes bass.) Consequently, the fly fisherman is initially faced with a critical choice: replicate the smaller more prevalent young crawfish, or the big meal older crawfish. In large part, the decision may be dictated by the fisherman's choice of equipment. Large heavy crawfish flies take larger rods.
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