Using a bioenergetic model to assess growth reduction from catch-and-release fishing and hooking injury in rainbow trout, Oncorhynchus mykiss

A bioenergetic model was used to predict the potential effects of feeding cessation caused by catch-and-release capture and a reduction in feeding efficiency from hooking injuries on rainbow trout, Oncorhynchus mykiss (Walbaum), growth in southwest Alaska, USA. Simulations indicated that a 1-day feeding cessation for a rainbow trout captured one to two times during summer months resulted in deviations from expected growth of -3% to -15%. To represent debilitating hooking injuries, the proportion of the maximum feeding potential was decreased by 5-50% resulting in deviations from expected growth of -9% to -164%. Simulated growth effects were most prominent from captures during months when salmon eggs and flesh constituted the majority of the trout diet. Simulated growth effects from reduced foraging efficiency were most prominent when hooking injuries occurred early in the fishing season. These simulations suggest that rainbow trout are most vulnerable to decreases in growth when salmon are abundant and spawning and, coincidentally, during the months when most fishing occurs.