A Method of Estimating Minimum Size Limits for Obtaining Maximum Yield

Abstract

When the rate of growth and rate of mortality of fishes are expressed in instantaneous or exponential terms, they can be directly compared and a "critical size" detd., at which they are equal. Such a detn. ordinarily applies to a year-class as a whole, but it is probably also fairly applicable to the fish individually, in which event it can be used to estimate the best minimum size at which they should be taken, in order to achieve max. production at the existing rate of fishing. The best min. size varies with rate of fishing, being zero when the latter is very small, and approaching the critical size as fishing is increased indefinitely.