Selectively removing fish based on particular traits, such as body size, may shift trait abundance in the remaining population, resulting in a phenomenon called fisheries-induced evolution. Recently, there is growing interest in evaluating the effects of fisheries-induced evolution on fish behaviour. Aquatic protected areas (APAs) have been designated in some habitats in efforts to prohibit harvesting and maintain natural ranges of phenotypic variation for impacted species. Here, we attempted to test whether APAs that prohibit all forms of fishing have an evolutionary influence on adult largemouth bass (Micropterus salmoides) behaviour by investigating the relationship between capture method and behavioural type. Fish, caught via active (angling) and passive (hoop net) capture techniques in both protected (70+ year old APAs in eastern Ontario) and adjacent nonprotected areas, were subjected to standard tests of boldness (refuge emergence, general activity, and flight-initiation-distance). A behavioural syndrome characterized by consistent within-individual variation and correlation of boldness behaviours (activity and refuge emergence) was present. Our results provide evidence that APAs may promote behavioural diversification and protect traits selectively targeted by recreational angling.

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Fish are commonly sedated to render them immobile and thus easier to handle for research, veterinary, and aquaculture practices. Since sedation itself imposes a significant challenge on the targeted fish, the selection of sedation methods that minimize physiological and behavioral disturbance and recovery time is essential. Two popular sedation methods include the chemical tricaine methanesulfonate (MS‐222) and electrosedation. Although many studies have already investigated the physiological consequences of these methods, there is limited research examining the latent behavioral effects on fish. Using Largemouth Bass Micropterus salmoides as a model species, we compared the postsedation behaviors of fish that were sedated with either MS‐222 or electrosedation to those of a control group exposed to the same handling protocol. Immediately after sedation, fish exposed to either treatment demonstrated lower reflex scores than the control group. Time to resume regular ventilation did not differ between chemically sedated and electrosedated fish; however, electrosedated fish regained equilibrium faster (mean ± SE = 154 ± 20 s) than fish that were exposed to MS‐222 (264 ± 30 s). Locomotor activity and swimming performance were assessed at 5‐, 30‐, or 60‐min intervals, beginning after individuals had recovered from sedation sufficiently to regain equilibrium. For all postsedation intervals, locomotor activity was two times greater in the electrosedated group than in the control and MS‐222 groups. Other behavioral measures (refuge emergence time, activity level, and flight initiation distance) and swimming performance did not differ at 5, 30, or 60 min postrecovery for any of the treatment groups. Our results indicate that while both chemical and electrical sedation methods result in impairment (i.e., sedation) immediately after treatment, these behavioral effects do not persist beyond 5 min postrecovery, and the two methods have similar impacts on Largemouth Bass. However, we caution that these results cannot be extrapolated to other fish species without further study. Received September 27, 2016; accepted January 17, 2017 Published online April 3, 2017

Individuals travelling through landscapes may use the presence of conspecifics to evaluate habitat quality. Juvenile Atlantic salmon (Salmo salar L., 1758) are usually territorial and exhibit some degree of density-dependent regulation in wild populations. They are also vulnerable to heat stress and may need to locate a thermal refuge to offset metabolic costs above certain temperature thresholds. During July 2010, a heat wave resulted in water temperatures in the Miramichi River system exceeding 30 °C. During this period, salmon parr were observed aggregating in cold-water refugia at densities several orders of magnitude greater than usual. We tested whether groups of wild-caught salmon parr held at high densities (160 parr/m2) would have an attractant effect on free-swimming parr at three sites differing in temperature between 16.5 and 24 °C. Although neither temperature nor site influenced the number of parr that we observed, there were significantly more parr in close proximity (<1 m) to the artificial aggregations than to the controls. These results suggest that social cues from high-density aggregations of conspecifics during extreme temperature events may advertise the location of thermal refugia to others. Understanding how heat-stressed salmon locate refugia may prove valuable to ongoing conservation efforts given the likelihood of increasingly frequent and extreme high-temperature events.