Catch and release (C&R) is routine for bass anglers concerned about the quality of their sport. Several studies have shown that most released bass survive, many are recaptured, and that C&R leaves more quality-size bass to support future angling. But few field studies have addressed the effect of releases on the growth of bass in natural waters.
A 27-year mark-recapture study of largemouth bass caught and released in Wisconsin provides insight into how released bass fare.* A total of 1,054 bass averaging about 10 inches in length were landed using barbless hooks and briefly held in livewells prior to weighing, measurement, tagging, and release. Recaptures totaled 1,066 and occurred between one and 98 days after initial release. About 39 percent of all fish captured were never recaught, 20 percent were caught only once again, and 8 percent twice; but the remaining 27 percent were re-landed between 4 and 22 times. Near-adult largemouths weighing about a pound or more had significantly longer recapture intervals than juvenile bass, suggesting that bass learned angling-avoidance with age.
Recaptured bass initially suffered a slight weight loss that lasted about 6 days. Then growth resumed, and there appeared to be a compensatory period of more rapid growth whereby bass regained weight to match bass from the same water that were not caught. The authors conclude that C&R angling had little impact on overall growth patterns of largemouth bass. However, larger bass likely have higher metabolic losses and longer recovery times following capture, so additional studies of C&R effects on larger largemouth bass are needed.
*Cline, T. J., B. C. Weidel, J. F. Kitchell, and J. R. Hodgson. 2012. Growth response of largemouth bass (Micropterus salmoides) to catch-and-release angling: a 27 year mark-recapture study. Can. J. Fish. Aquat. Sci. 69:224-230.