Mid Level Predators
Perhaps no other fish generates more fishing interest in North American waters than the Mid-Level Predators. These are fish that are both strong, opportunistic, yet skiddish. At times regressive yet often subtle. Fish big enough to challenge one's equipment and savvy enough to challenge one's skills. Fish that can be challenged with a dizzying array or approaches and selective enough to evade them all (sometimes).
What is a Mid Level predator?
A mid level predator is an aggressive predator that eats fish and other organisms yet still lacks the size (even when mature) to be a dominant predator in the environmental. Due to its vulnerability in its environment it is both aggressive in the presence of prey yet remain skiddish and wary.
In North America, During the early part of the 20th century, Fishing progressed from an activity to supply supplemental food to a sport to outwit the savvy of fish by means of altering a hook to look like or act like prey. In this new sport, certain fish better met the desired characteristics and were called gamefish. Most of these original gamefish are midlevel predators. Increasing interest by fishermen led to stocking these fish throughout most of North America. There common characteristics need understood by anybody whom hopes to target them.
Common yet skiddish
Probably the biggest reason for many fishermen failing to catch gamefish is to be too careless in ones approach and technique. Many of these gamefish will pursue feeding activities in shallow water in loose to dense schools (or groups) of fish. This can be some of the most exciting non-step action an angler can experience. It will quickly change however if an angler betrays his position by vibrations, motions, or sudden splashes. Furthermore It is very careful that an angler both approaches the fish, carefully and uses tackle that doesn't betray his purpose.
Diverse in technique yet selective
Gamefish are nearly by definition opportunistic. Usually they are too common to survive merely on baitfish and will feed on crustaceans, amphibians, and insects to make up for the heavy demands of fighting the rivers current. Thus many different lures and baits might create a feeding response. Gamefish are most likely to be tempted by an approach that imitates its dominant food. The feeding style can change drastically over the season. For example, when large stoneflies begin to stir on a rivers bottom. Large imitation nymphs can catch even large predators like big walleyes and bass; however later in the year, such an approach might be fruitless. Gamefish often go on feeding binges where they will unselectively attack many different lures, if the lure is worked at the right place and at the right depth. Sometimes the differences between an effective approach and an uneffective one defy understanding; but often an experienced angler has widely experimented with his technique and has a set of techniques and lures that are successful under many different conditions. The idea that experimentation and technique might catch gamefish that evade most other fishermen's approaches has created the sport of competitive fishing.
Keeping up with the crowd
The reality of this new emphasis on sports fishing, is that especially in certain places, gamefish are repeatably caught and released. This is a favorable force upon fish density, allowing many anglers to share a resource that is lightly stocked (if not entirely self reproducing). The other side of this ,though, is that fish populations tend become a lot more wary. After the first few catches; fish adapt to the human threat as they do for other formidable predators. Often these fish become highly selective and become resistant to common approaches. Lures become markedly less effective and experienced fishermen often have to experiment widely with new technique to catch fish. In extreme cases these fish can not be regularly caught with lures
Catch and release rates (versus harvest) have gotten so high that midsized individuals dominate ecology and overpopulate. In some waters, it would be an ecological kindness to harvest a few midsized individuals. Nearly all gamefish are delicious and anglers should be conscientious in deciding their policy about keeping gamefish (and of course, follow all applicable state laws regarding that).