Non-random mortality associated with commercial and recreational fisheries have the potential to cause evolutionary changes in fish populations. Inland recreational fisheries offer unique opportunities for the study of fisheries induced evolution due to the ability to replicate study systems, limited gene flow among populations, and the existence of unexploited reference populations. Experimental research has demonstrated that angling vulnerability is heritable in Largemouth Bass Micropterus salmoides, and is correlated with elevated resting metabolic rates (RMR) and higher fitness. However, whether such differences are present in wild populations is unclear. This study sought to quantify differences in RMR among replicated exploited and unexploited populations of Largemouth Bass. We collected age-0 Largemouth Bass from two Connecticut drinking water reservoirs unexploited by anglers for almost a century, and two exploited lakes, then transported and reared them in the same pond. Field RMR of individuals from each population was quantified using intermittent-flow respirometry. Individuals from unexploited reservoirs had a significantly higher mean RMR (6%) than individuals from exploited populations. These findings are consistent with expectations derived from artificial selection by angling on Largemouth Bass, suggesting that recreational angling may act as an evolutionary force influencing the metabolic rates of fishes in the wild. Reduced RMR as a result of fisheries induced evolution may have ecosystem level effects on energy demand, and be common in exploited recreational populations globally.

Annual tournament‐associated mortality of largemouth bass Micropterus salmoides and smallmouth bass M. dolomieu (≥30 cm) was quantified at Mansfield Hollow Reservoir and Gardner Lake, Connecticut, during 2001 and 2002 to determine the effects of tournaments on black bass populations. Nontournament and tournament anglers followed a 30‐cm minimum length limit during both years. Tournament anglers—but not nontournament anglers—were exempt from new, more restrictive regulations (a 30–41‐cm protected slot length limit at Mansfield Hollow Reservoir; a 41‐cm minimum length limit at Gardner Lake) imposed in 2002. Annual tournament‐associated mortality of largemouth bass was 2.4–8.4% of total annual mortality, 1.0–3.2% of the population size, and 2.0–20.8% of annual fishing mortality. For smallmouth bass, tournament‐associated mortality was approximately 7% of total annual mortality, 4% of the population size, and 29–52% of annual fishing mortality. Based on the levels of total annual mortality, annual fishing mortality, and annual tournament‐associated mortality, impacts of tournament angling appeared low in these two lakes. Tournament‐associated impacts would have been lower if anglers were prohibited from exemptions. If exemptions were prohibited year‐round or only during the summer, 80–94% of the tournament catch would have been immediately released. Relative to fishing effort, tournament anglers in Connecticut contributed a greater proportion of annual fishing mortality than nontournament anglers. In lakes where tournament‐associated mortality is high, prohibiting exemptions (especially during summer) may help to reduce tournament‐associated mortality. In lakes with low tournament impacts, allowing exemptions (except during summer) may protect tournament angling opportunities for most of the fishing season, while at the same time decreasing tournament‐associated mortality during the warmest months.

Factors related to the initial and delayed mortality of largemouth bass Micropterus salmoides and smallmouth bass M. dolomieu were determined at small club tournaments held at two Connecticut lakes during April–October of 2001–2002. Organizational characteristics of tournaments, environmental conditions, and initial mortality data were collected from 58 tournaments at Mansfield Hollow Reservoir and 41 tournaments at Gardner Lake. Delayed mortality at 72 h was also determined for 29 tournaments at Mansfield Hollow Reservoir and 25 tournaments at Gardner Lake. In total, 3,290 largemouth bass and 1,035 smallmouth bass were observed for initial mortality; 1,784 largemouth bass and 647 smallmouth bass were observed for 72‐h delayed mortality. Initial and delayed mortality rates were 2.2% and 1.0% for largemouth bass and 4.8% and 2.8% for smallmouth bass. Logistic regression indicated that initial mortality was significantly greater (P < 0.0001) for smallmouth bass than for largemouth bass, and that initial mortality was positively related to water temperature (P < 0.0001), total handling time (P < 0.0001), and fishing‐day length (P = 0.0357). Delayed mortality was positively related to water temperature (P < 0.0001), and there was a significant species × lake interaction (P = 0.0152). Initial mortality began to increase sharply at water temperatures greater than 25°C. Delayed mortality showed differential responses to water temperature depending on the species and lake. Our results suggest that tournament‐associated mortality may be reduced by limiting tournament activity during the hottest months and by increasing the efficiency of weigh‐in procedures at small club tournaments.

Emotional stress is often followed by increased susceptibility to infections. Natural killer (NK) cells play a major role in the immediate immune response controlling this susceptibility. In this study on 45 first-time parachutists, it is demonstrated that highly controlled psychological stress increased psychophysiological variables, enhanced the secretion of sympathetic-adrenal hormones and also led to a significant increase of NK cells and their cytotoxic activity followed by a decrease below starting values. This immunological alteration is correlated with the secretion of noradrenaline during the emotional strain. Quick mobilization of these cytotoxic effector cells is suggested as a major mechanism for the effective adaptation of the immune system to stress situations.

Recreational fishing represents a coupled human and natural system subject to complex feedback processes. Learned lure avoidance represents one feedback process that may influence a fish population's vulnerability to angling. In the present study, naïve Largemouth Bass Micropterus salmoides originating from fished and unfished populations were raised in a pond and subjected to standardized angling. Our objectives were to evaluate the initial angling vulnerability and the rate at which naivety to angling was lost for fished and unfished populations. While no difference in initial angling vulnerability existed among fish from fished and unfished populations of origin, individuals from fished populations learned lure avoidance faster than individuals from unfished populations. Cumulative catch events, a metric that incorporates the number of opportunities individuals had to directly and indirectly experience angling, best predicted declining daily catch rates for both fished and unfished populations, suggesting a social learning component of learned lure avoidance. That individuals originating from fished populations learned lure avoidance more quickly than unfished individuals suggests that angling selected for increased learning ability in fished populations of Largemouth Bass. Received February 4, 2016; accepted May 18, 2016 Published online August 12, 2016