But certain fish species, such as those described below, are considered prey or forage fish for their entire lives. The term prey fish is actually a loose term used by people to refer to certain non-game fish species that are the main food items for popular sportfish. As a rule, a fish is considered a prey fish if it remains small enough in size during its entire life cycle and it occurs in large enough numbers to adequately feed a predator fish population. In addition, these fish are generally not used by people other than for bait. But while prey fish are mostly considered a significant food source for popular gamefish, it is important to remember that they are also an essential and integral part of a healthy fish community.
Prey fish help maintain balance in the fish community.
They play the role of predator by eating the larvae of other fish species, including young sportfish, as well as play the role of competitor by eating the same foods as other fishes. If something happens to the prey fish population, the entire fish community is affected. The alewife is a small river herring with a gray-green back and silvery iridescent sides. It occurs in open water areas of large lakes and can be found as deep as 300 feet. A schooling fish, the alewife forms large groups in midwater.