Meeting Abstract
Recent work suggests that fisheries-induced selection may act on directly on behavioral characteristics in addition to life history traits. These behavioral tendencies, which may include correlated levels of boldness and activity as well as underlying stress-hormone responsiveness, are often referred to as “behavioral syndromes” or “stress coping styles”. It was the goal of this study to measure boldness and cortisol responsiveness to stress in largemouth bass Micropterus salmoides taken from an experimental population selected for differential vulnerability to angling, and to determine if these traits influenced the likelihood of capture. Fish were subjected to an open-field test to evaluate boldness, then had blood drawn to determine levels of plasma cortisol in response to an air-exposure challenge. The fish were then stocked into an experimental pond where a week-long series of angling sessions took place. Binary logistic regression modelling was run following these trials to evaluate the effects of fish size, selected line, boldness, and baseline/post-stress cortisol levels on the probability of capture. Of these, post-stress cortisol levels emerged as a significant negative predictor of whether the fish was captured (p<.03). Cortisol levels (baseline and post-stress) were not correlated with boldness levels in bass in this study. Our findings that fish with higher post-stress cortisol levels were less likely to be captured provides further evidence that fisheries-induced selection may act on behavior and physiology in addition to life-history traits.
