A study of food competition between fish species inhabiting a marginal trout stream.

Abstract

The author's intent in this study was to obtain quantitative data on food competition relationships between nongame fishes and Salmonoids inhabiting a stream considered marginal for the Salminoids. The approach was to determine the fish community's food selection habits by species and length group in order to find the amount of competitive overlap. For the purposes of this paper, competition was considered to occur when the same food organisms were eaten by several species of fish. In conclusion it must be emphasized that overlapping food habits do not prove that in a broader sense, competition exists. Many adjustments, such as time or place of feeding, may serve to reduce this element. Furthermore, overlapping food habits on a forage animal this is superabundant may not be true competition (Keast, 1965). This then is but one aspect of a competition study.