Behavioural and metabolic consequences after a single generation of angling selection in brown trout

Human induced selection, including mortality caused by recreational angling, can cause phenotypic changes in wild populations. Brown trout (Salmo trutta) is an intensively fished salmonid that is also impacted by unintended hatchery-induced domestication, and thus provides a relevant model to study both fishing- and hatchery-induced selection. We produced crosses of fish with high or low vulnerability to angling using two populations of brown trout, one wild and one reared in captivity for several generations, and reared the offspring in common garden conditions. We then assessed minimum and average metabolic rates, boldness and sensitivity to stress in juveniles at the age of 1 year. Our results show that angling selection had population-specific effects on boldness-related latency and exploration tendency, and that populations differed on average in several measured traits, which could be due to a combination of genetic and non-genetic effects. Our study provides evidence for angling induced selection in juvenile personality and suggests that metabolic rate and stress sensitivity may also be affected. The context-dependent effects of angling selection indicate that easy solutions for fisheries management and conservation purposes to mitigate these changes may not exist.