ABCs of Structure Bassin

Since the word structure is often misused and misunderstood, let's try to pin it down. A definition of structural elements could read: changes in the bottom depth or shape from surrounding bottom areas. One of the most obvious examples of a structural element is a creek channel. Creek channels are particularly important because most of our lakes are impoundments. As you know, an impoundment is created by building a dam across a creek or stream. The dam holds back the flow of water. The water floods the creek banks and forms a lake. Although you can no longer see it, the original creek channel is still down there, with its twists and turns and steep banks. It is a major structural element. Of course, there will be a dropoff on each side of the creek channel where the bank drops into the stream bed. In the terminology of structure fishing, this dropoff is called a breakline. A breakline is an underwater edge, and an edge is something that a bass likes to relate to. Contour maps of your favorite lakes will clearly show the creek channel. If you don't have such maps, acquiring them should be your first step in learning structure. The maps will have contour lines, often in five foot depth intervals, outlining the shape of the bottom. In addition to the creek channel, other obvious structural elements you should be able to find on the maps are points and dropoffs. Some lakes will also have underwater islands. You will find a point wherever the map's contour lines curve out towards midlake (see diagram A). A dropoff is indicated when several contour lines are bunched close together (see diagram B). Sunken islands could look like irregular circles on the map (see diagram C).

In addition to lake maps, you will need a depth finder. With this tool, you can locate and see the structural elements you find on your maps. Also, it will help you turn up much additional structure not shown on the map. This treasure hunt for structure is fun and will teach you a great deal about your lakes. Although your depth finder will give you a good idea of what your bottom is like, nothing beats actually feeling the bottom. To do this, tie a jig (3/8 oz. or heavier) with a weed guard to your line. The jig is an excellent bass lure, and it is likely to be taken by a walleye, pike, or any other predatory species that lives in the lake. It will give you a good idea of what kind of gamefish, if any, are using a particular structure. Moreover, the jig is an unbeatable reconnaissance tool. The hard lead head clearly telegraphs up the line whatever it bumps into. It will take practice, but once you tune into your jig, you will easily be able to tell: whether the bottom is gravel, rock, or boulders: if there are weeds present and, if so, how thick they are; and if there are stumps, trees or stickups cover. Feeling the bottom is important. It will better etch in your mind the shape of the structure. It will, also, let you know if there is cover on the structure. Cover is crucial. You may find a piece of structure that has a distinct breakline, but if it doesn't have cover on or near the breakline, it will produce few, if any, bass. Cover is what holds the bass. They use it as a resting place and as an ambush point. Without cover, there is nothing to invite the bass to stay. Consequently, they just pass on by. Bass love wood cover, and seem to prefer it on many impoundments. But on some lakes, weeds are the dominant cover, and on others boulders may be more prominent. The bass will make use of whatever cover is available, so be sure the structural elements you fish have some type of cover capable of holding fish. One thing that confuses beginning structure fishermen is that they think structure only occurs in deep water. Deep water is generally referred to as depths greater that eight feet. The key is to find structural elements with cover that are in the proper depth zone for the lake you are fishing. As a general guideline, the darker the water, the more shallow the fish. If your lure disappears after it sinks two feet, you may be wasting your time plying the depths. In such murky water, you are more likely to find bass shallow. Remember, just because a dropoff only goes from four to eight feet instead of 12-25 feet, it is still a structural element with a breakline. If it has cover, it is capable of holding bass. Since many impoundments have stained water, you'll catch most of your fish no deeper than 15 feet. Keep in mind, however, that different areas of a lake will have different water clarity. You will have to change your depth according to where you are fishing. (For example, you are fishing far up a lake near the main feeder creek. The water here, as in most lakes, is the least clear. You'd probably fare best by fishing shallow. If you were to boat several miles to the deep water near the dam, the water color would probably be much clearer. The productive depth here could be as much as 12-18 feet). Another important consideration is the season. In spring, when the bass are motivated by spawning urges, they will move to structure close to shallow spawning bays and flats. During the summer, you may find the largest concentrations of bass holding on structure near flats or points that taper gradually from shallow water to the breakline. These flats, if they have cover that will attract forage species and hold the bass, could be major feeding areas. In the cold months, the fish may move to structure that drops more sharply into deep water. They do not have the energy then to make long movements from deep to shallow or vice versa. A steep drop allows them to move up or down quickly and with little effort. Once you've located structure that you believe hold bass, you must present your lures in a manner that will attract the most stikes. One basic and high percentage presentation is parallel casting. To cast parallel, position your boat right on the breakline and cast parallel to it (see diagram D). This will put your lure in productive water throughout the retrieve. You'll find this presentation particularly effective when fishing stump rows. Another basic presentation is to cast towards shallow water and bring your lure towards deep water (see diagram E). If there is any cover, such as weeds or stickups in the shallows above the breakline, be sure your lure comes into contact with it before you bring it out. At times you will be more successful if you position your boat in shallow water and cast out over the breakline to deep water. Then bring the lure back in over the breakline (see diagram F).

The lures you use with these presentations depends on the depth of the structure you are fishing, the cover, and on how active the bass are. In deeper water than 10 feet, you could fish effectively with jigs or Texas rigged plastic worms, perhaps even a fast sinking spinnerbait. Along a shallow breakline with cover, you might try a spinnerbait near the surface. If the bass are not in an active mood, a plastic worm may coax strikes. If you've found active bass along a stump row eight feet deep, a fast retrieve with a crankbait could do the job. If the bass are lethargic, a slow retrieve, or switching to a bottom bumping lure may be necessary. As you can see, finding structure does not guarantee that you'll catch bass. Structure is part of the overall picture. If you are to progress as a bass angler, it is imperative that you learn the rudiments of finding and fishing structure. Hopefully the basics presented here will get you on the right track.