The Frankenstein Effect: impact of introduced fishes on native fishes in North America

There is a long tradition of tinkering with fish faunas by introducing new species to improve on nature. Modern fisheries biologists take measures to solve immediate and/or local problems without considering the long-term or broad-scale effects that are usually negative. Too often the introduction of new fish species is made to improve local fisheries without consideration of their effects on the native fish communities. The usual result is the extirpation of native aquatic organisms, especially other fishes. The purpose of this paper is to see whether some of the recent advances in ecological theory can be applied to understanding and predicting the impact of introductions on native organisms. This paper asks the questions: 1) What is the extent to which introduced species have become part of the fish faunas of North America? 2) What kinds of effects have introduced species had on native species? 3) What are the ecological mechanisms that allow introduced species to become established or dominant in new environments? 4) Do introduced species fill vacant niches or how can ecological theory help us to predict the potential impact of introductions?