Fishful Thinker: Defining The Playing Field Part I

In my opinion, fish are not terribly difficult to catch. I mean, geez, they have tiny little brains and great big mouths - how hard could it be to trick them into eating? Not very in many cases, but the real trick and ultimate key to consistent success lies not in getting them to bite. Nope, not even close. The real trick is finding them in the first place. It won’t matter how perfect your bait and presentation are if you’re not deploying it around fish. So, let’s talk about finding fish, fast.

There are lots of things to consider when locating fish. Seasonal effects on their movement must be considered at the macro level, along with daily or even hourly effects caused by weather. Water temperature and clarity must be considered, along with available forage, wind or current direction, water level fluctuation and a slew of other variables. But before any of those decisions can be intelligently made in a real-world circumstance, you have to understand the playing field, otherwise known as the lake or river you are considering. We need a system to apply to the decision making process and to be effective, it needs to be rooted in the lowest common denominator of fish location - structure. If 90% of the fish are in 10% of the water, obviously, you need to locate that 10% pretty quick and it starts with the structure.

Structure “IS” the playing field. It defines the outline of the lake or river, shapes the bottom thereby defining depth and becomes the basis from which all other angling decisions are made. If you don’t understand the structure of a body of water, everything else is conjecture.

How is that? Well for instance, you may know that it’s nearing spawning season for your beloved largemouth bass and even that they like to spawn on flat banks. But, if you don’t know how to quickly locate those banks and even more importantly (especially on big lakes) how to eliminate some of them based on overriding structural elements, the fact that you know they are thinking spawn is worthless information. Or let’s say you do know exactly where they like to spawn on your lake, but they aren’t quite there yet. Where are they staging or what route might they use to get there such that you can intercept them?

Structure is “NOT” cover and cover is not structure. Despite anglers commonly interchanging those terms, structure is far more important than cover. Structure defines the shape of the waterway in three dimensions. It is the actual bottom of the lake and dictates the shoreline at any given water level. Cover is anything that sticks up off the bottom or out from the shoreline. In short, cover gives detail and texture to structure. Structure trumps cover, such that good structure will always have potential, but even the best cover is basically worthless if it’s not located on or very near good structure.

How do we learn the structure of a lake? Topographical maps are the best place. As much as I rely on my Lowrance SONAR and Genesis Insight mapping, I still prefer a paper map for big picture study. I like to lay it out and get a “feel” for my destination. Is it a canyon style reservoir like Lake Powell or perhaps a highland impoundment like Table Rock Lake or maybe a lowland reservoir like Sam Rayburn? Each have their own structure styles. I like to compare the paper map to online aerial imagery; this is the first chance to see what cover may be around what structure. There might be a dozen similar small pockets just off the main lake, but two of them have boat docks. I’ve instantly narrowed my fish search. I might be looking for defined creek channels (they are the fish highways), points, breaks or humps based on the habits of my preferred species and their season preferences, but regardless, it starts with the structure.

Once I launch the boat, I can verify with SONAR what the map lead me to. On the water, I can determine which great structure has the best cover and start fishing there. Once I find my target fish, I can then extrapolate to other similar areas I observed on the maps and navigate there using the mapping in my Lowrance unit. Pattern fishing 101.

I’ve often said that river fish are easier to catch than lake dwellers of the same species because the structure of the river bed is so much easier to analyze. In most cases I can see it clearly or at least read it from the current flow. Here again, structural elements can be easily scouted ahead of time with maps and aerial imagery. In this case, I’m looking at runs, flats, pocket water, large pools, falls, etc. Once I determine trout are concentrated in, say, fast riffles, I can easily concentrate my fishing in productive water.

Knowing the structural and cover preferences of your favorite species is a major part of this puzzle. But regardless, you still have to understand the structure first to apply that knowledge. In next month’s column, I’ll address cover; how to assess what makes good cover and how it relates to structure for best results. I’ll leave the fish preference study to you, because once you understand structure and cover, the fun part of the sport becomes the fish hunt.