Fundamentals Of Fish Location

Understand the basic criteria that influence where fish live.

When asked why he robbed banks, famous outlaw Willie Sutton supposedly quipped, “Because that’s where the money is!” Whether or not he actually made the oft-quoted reply, the philosophy is sound. Even when it comes to fishing. If you want to catch fish, you have to go where the fish are. It’s often been said that 100 percent of the adult gamefish are located in 20 percent of the lake, no matter where you fish. That leaves an awful lot of empty water, so the quicker and more effectively you eliminate it, the faster you can locate and catch fish.

Largemouth Habitat
In the last segment of this series, we examined the different types of impoundments found throughout North America, and highlighted the characteristic environments they offer bass and other gamefish. We’ll do the same with natural lakes and rivers in the future, but for now, let’s focus on the primary types of habitat that host largemouths most of the time. In most waters where an appreciable number of bass are present, we know that we will find some amount of cover. In natural lakes, the best cover is typically weedgrowth. In reservoirs where the water levels fluctuate enough to prevent rooted weeds from developing, cover is more likely to take the form of flooded brush, trees, logs, stumps, or perhaps floating boat docks.

Now, that doesn’t mean you’ll never find them around rocks or boulders, because you will. However, those kinds of areas tend to be better habitat for smallmouth bass. Smallies typically thrive in waters, or areas within a lake, where a sandy bottom with scattered rock predominates. In waters where both species reside, that’s simply the way they co-exist. When sizing up a lake, river or reservoir for largemouth bass, we look at a number of primary locational criteria which are summarized in the accompanying chart. The combination of these factors determines where the fish live, what they feed on and how well they prosper. And ultimately, how and where you can catch them.

Criterion 1: Water Body Makeup
We’ll divide Criteria 1 into three categories, all of which are related to the physical environment. The first two are fairly obvious to most anglers, the third less so. Because largemouths are so coveroriented, the first of these categories is Vegetation or Cover Content. Weed cover varies throughout the course of a year, while wood cover tends to remain fairly consistent, though it slowly deteriorates over time. Rock, on the other hand, remains unchanged over a lifetime unless shifted by ice, strong currents or man’s intervention.

Next comes Structure and Bottom Content, meaning the physical shape, depth and bottom substrate of an underwater area. Structure in lakes changes only slowly over many years, while river structure is subject to the effects of floods and can change from season to season. Portions of reservoirs may experience siltation over a period of years, while others remain unaltered unless water levels change drastically, subjecting the surroundings to erosion. By and large, off shore humps, long extended points, slow-tapering drop-off s, inside bends and other structural characteristics in both lakes and reservoirs remain largely unaffected by wind, current or erosion. The third category in this section is Water Chemistry—characteristics like oxygen content, water clarity, fertility and acidity of the water itself. In general, a clear lake tends to remain fairly clear throughout the year, although spring runoff or excessive rain can temporarily reduce clarity. Likewise, algae blooms can cut light penetration, as can inflowing water from muddy or tannin-stained tributaries. Of the three categories mentioned, this is perhaps most impacted by outside factors, as explained in the next section.

Criterion 2: Outside Impact Factors
This set of criteria can be broken into three categories as well, all of which are outside influences that affect living conditions, at least temporarily, in a body of water. Seasonal Variations is the first and most obvious. They bring with them changes in air and water temperature, length of daylight and sunlight penetration, and a parade of constantly fluctuating weather conditions. Most of these are easily recognized by anglers as having some effect on fish location and their willingness to bite. Other factors, however, tend to be more subtle, and their effects underappreciated.

For example, a lake with darker water absorbs sunlight faster, warming more quickly than a nearby clear lake. Therefore, a bass’s prespawn, spawn and postspawn periods occur earlier, even if the clear lake is structurally equivalent. Insect hatches might occur earlier in the year as well, triggering summer patterns before the clear lake experiences them.

In the grand scheme, weather can be lumped in with seasonal variations. Local patterns, such as cold fronts and warm fronts, affect bass location and activity. For instance, warming weather raises water temperatures in early spring and triggers bass to move into prespawn areas. Cold fronts, however, do the opposite, causing them to retreat to adjacent deeper areas, reducing their feeding activity until weather conditions improve.

The effect of Human Usage on bodies of water, a second category, introduces an unnatural element to the environment. Heavy recreational traffic, fishing pressure, angling harvest, reduction of lakeshore habitat, runoff from agricultural or developed land, and other things combine to alter the places fish live, reproduce and feed. Seldom does fishing get easier or better as human activity increases; in fact, bass in heavily fished lakes typically become more reluctant to bite. Yet, they generally find ways to adapt to outside influences, such as feeding more at night or shifting to secondary, less obvious living areas that escape the brunt of fishing and boating pressure.

The third category in this section is Other Factors, which are basically not caused by man on a daily or weekly basis, yet are attributable to human influence or behavior. For example, the introduction of invasive species such as zebra mussels, Eurasian milfoil, spiny water fleas, rusty crayfish, Asian carp and other alien organisms presents a real danger to fisheries. Whereas natural changes like erosion and siltation tend to take place over hundreds or thousands of years, invasive species can rapidly alter the food chain, water clarity and fertility, feeding locations and strategies, and even the balance of species, in a few short years.

Prior to the introduction of exotic weed species, the extent and pattern of weedgrowth in natural lakes primarily depended upon water color and chemistry, and bottom type. If the lake had dark water, weeds were restricted to the shallows; if the lake was clear, they grew much deeper. Yet the introduction of invasive weeds like hydrilla and milfoil generally displaces a large portion of the natural growth in quick order. Likewise, clearing water attributable to the filtering action of zebra mussels can cause weeds to grow deeper than they otherwise would. As a result, angling patterns can change radically, especially for species like largemouth bass that readily adapt to these new weeds as prime habitat.

Criterion 3: Community Living Conditions
Once you begin to understand a body of water—its makeup, how it functions on a day-to-day and seasonal basis, and how fishing pressure might affect fish location and behavior—you need to take into account one additional component: Namely, how fish like largemouth bass live in harmony with their “neighbors.” The neighborhood includes not only other bass, but the prey they feed upon, as well as other predators with whom they compete for territory and food. Three categories in this section are all basically part of the natural environment. The first is Population Density. Obviously, the greater the number of bass in a body of water, the easier they should be to catch. It’s not always true, but it tends to be.

Lakes can support only a finite number of pounds of gamefish; this is known as “carrying capacity.” In trophy bass waters, large adults tend to dominate the population. Either because the conditions for growth are optimum, or there is little fishing pressure that removes adults from the system. Other waters—notably those with heavy fishing pressure—tend to host many small bass, but relatively few big ones. And of course, many waters fall somewhere in between.

The second category in this section is Type and Availability of Prey. This, too, plays a huge role in the number of fish present, their average size and their potential for achieving trophy status. If food is scarce, or the primary forage is of poor nutritional value, size will suffer. For example, if bass are limited to eating small minnows or insects, rather than more nutritious forage like shad or bluegills, they may be numerous, but are likely to be stunted. At the opposite extreme, having large, highly-nutritious prey available, as do bass in lakes that are routinely stocked with trout, is conducive to growing giants—although perhaps not in vast numbers. Again, as you might expect, the majority of waters fall somewhere in between.

In all cases, however, the location of the forage determines the location of the bass. As forage levels seasonally peak and ebb—and as bass switch to other sources of forage that nature makes available on a seasonal basis—the fish change location and feeding strategy to take advantage of the newfound bounty. As they do, fishing locations and angling patterns are likely to change as well. The third category in this section is Interspecies Competition, which takes into account how bass share their habitat and food sources with other major predators such as stripers, pike, muskies or walleyes. In southern or western impoundments with relatively few predator species, interspecies competition is often limited and bass can pretty much go wherever they want. But competition is a major factor in northern natural lakes that hold multiple predator species, and gamefish often share the same space for feeding.

Finding Fish
Now that we’ve examined these intriguing factors, how do they help us locate and catch more and bigger fish? Bass are part of an aquatic community, and must adapt to all the conditions they face, not just a select few. As such, they must locate in areas where sufficient food and cover is available, relating and adapting to local structure and circumstances. Where necessary, they may need to share the available food and habitat with other species. And in many cases, try to avoid being caught or eaten along the way.

The ability to pinpoint and interpret underwater structure is certainly a big part of fishing success, and with the help of technologies like GPS, on-screen contour maps and detailed side-imaging, it’s quicker and easier to zero in on good fishing spots than ever before. Even so, there remains a critically important component to determining bass location: The better you understand the living conditions that bass face, the more likely you will be to find and catch them.

Considering the three Primary Locational Criteria—Water Body Makeup, Outside Impact Factors, and Community Living Conditions— allows you to complete the location portion of the angling puzzle. After that, it’s time to establish the proper lures and methods for catching the bass you’ve found.

You might be interested in this tool that will help you locate more fish.

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