Critical Size and Maximum Yield for Chinook Salmon (Oncorhynchus tshawytscha)

Publisher Website
Google Scholar
Abstract
Instantaneous natural mortality rate is estimated from tagging and recovery data and compared with instantaneous relative growth rates for each life history type of chinook salmon. It is demonstrated that critical size is not attained prior to maturity, hence, juveniles should be protected from fishing if maximum yield in pounds is desired. Yield cannot be increased by a minimum size regulation, for losses due both to direct injury and hyperactivity reduce critical size to levels not ordinarily encountered by existing fisheries. A further complication arises in that size is not a reliable indicator of maturity. The most feasible alternative to a minimum size regulation appears to be spatial and temporal restriction of the fishery to known concentrations of maturing fish, together with the encouragement of non-size-selective gear.

This publication has 4 references indexed in Scilit: