Fishing as a Cause of Evolution in Fishes

Abstract

This paper discusses the degree to which fishing causes evolution in fishes and how to detect and measure it. Fishing mortality is often very high and nonrandom with respect to several life-history traits that are at least partly heritable. Therefore. it seems likely that fishing causes evolution in fishes. Selective harvest of experimental populations has produced genetic changes in them. and natural selective agents. especially selective predation. have also caused genetic changes in populations of various species. However. the action of many other factors makes the detection and measurement of evolution difficult. so many observations that show changes in life-history traits of exploited fish populations are not sufficient by themselves to establish the occurrence of evolution. The difficulty of detecting and measuring evolution by observation alone should not be interpreted as evidence that evolution is not occurring; instead. it provides a oppommity for experimental research that has theoretical and practical importance. Some experimental approaches. which should be accompanied by simulations. are discussed.