Understanding how released fish recover following capture is vital information for researchers examining the effects of angling on exploited populations. This information is virtually non‐existent for fish angled through the ice in winter, despite the popularity of ice‐angling in many northern areas. To address this gap, 60 northern pike, Esox lucius L., were angled through the ice from an impoundment in eastern Wisconsin, USA, and subjected to one of ten combinations of handling and recovery duration. Plasma samples were collected and analysed for cortisol, lactate and glucose. The results showed a delayed response in the elevation of plasma variables, and a significant interaction between air exposure and recovery time for plasma lactate. No fish suffered mortality during the period of holding. Collectively, these data suggest that northern pike are physiologically resilient to ice‐angling capture stress as long as air exposure times are kept at 4 min or less.

We quantified physiological disturbance and reflex impairment in ice-angled bluegill and yellow perch. Rises in plasma cortisol and lactate following capture were lower than those found in prior studies done in summer. Recovery of plasma metrics did not occur within 4 h of capture, however, reflex responsiveness levels did recover.

Differences in behavior and physiology amongst individuals often alter relative fitness levels in the environment. However, the ideal behavioral/physiological phenotype in a given environment may be altered by human activity, leading to an evolutionary response in the affected population. One example of this process can be found in fisheries (including recreational freshwater fisheries), where selective capture and harvest of individuals with certain phenotypes can drive evolutionary change. While some life history traits and behavioral tendencies influencing capture likelihood have been studied, the physiological mechanisms driving this vulnerability remain poorly understood. To address this, we assessed how two major physiological characteristics (hormonal responsiveness to stress and metabolic phenotype) and one behavioral characteristic (boldness) impact the likelihood of an individual being captured by anglers. Largemouth bass, Micropterus salmoides, derived from a population artificially selected for differential angling vulnerability were assessed for boldness and for stress responsiveness (as indicated by plasma cortisol levels) following an air-exposure challenge. Largemouth bass were then stocked into a pond where experimental angling trials took place, and a subset of captured and uncaptured fish were afterwards assessed for metabolic phenotype. The results showed that stress responsiveness was the primary driver of angling vulnerability, with individuals that experienced lower rises in cortisol following the air-exposure challenge more likely to be captured. Neither boldness nor metabolic phenotype influenced capture probability. The results from this study indicate that fisheriesinduced selective pressure may act on physiology, potentially altering stress responsiveness and its associated behaviors in populations exploited by recreational anglers.

Many recreational anglers practice catch‐and‐release; however, research indicates that capture and handling has the potential to adversely affect fish. Numerous catch‐and‐release studies have been conducted during warmer months, but little work has been done during the winter when ice‐anglers in temperate regions target fish. We conducted an ice angling simulation that quantified the impacts of air temperature and air exposure duration on swimming performance and gill physiology of Bluegill Lepomis macrochirus and Largemouth Bass Micropterus salmoides. In all experiments, fish were first subjected to a simulated angling bout in water at 5°C, followed by 30 s or 5 min of air exposure at above freezing (3–8°C) or subfreezing (−7°C) temperatures. The fish were then assessed for critical swimming speed (Bluegill), oxygen consumption (Bluegill), burst swimming (Largemouth Bass), or gill damage (Largemouth Bass). Results showed that Bluegill subjected to 5 min of air exposure at −7°C suffered impaired swimming, with a 47% loss in critical swimming speed (Ucrit) compared with the controls. Treatment had no impact on burst swimming or gill damage in Largemouth Bass. The results demonstrate the possible impacts of air exposure on fish, and we recommend that ice‐anglers make an effort to minimize air exposure duration, especially when air temperatures are low.

When fish are brought to the surface quickly during angling, barotrauma is a concern (Butcher et al., 2012). Barotrauma results from rapid decompression due to sudden decreases in the external pressure of the surrounding water (Carlson, 2012). Numerous studies in warmer, open waters found capture depth of fish is correlated with barotrauma onset and severity, as water pressure is greater at deeper depths and the decrease in external pressure upon retrieval is larger (Butcher et al., 2012;

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Catch-and-release (C&R) ice fishing is a popular form of recreational angling. At present, there is a considerable deficiency in our understanding of how ice angling affects the physiology, behavior, and survival of fish. Thus, the purpose of this review was to summarize our current knowledge of the consequences of winter C&R fishing on fish biology and to identify key knowledge gaps. Our synthesis revealed that in addition to the typical stressors encountered from C&R fishing during the open-water season, fish that are caught through the ice are subject to several unique challenges, including exposure to subzero air temperatures upon landing as well as unique gear types that are not commonly used in the summer (i.e., passive angling techniques). We currently understand that while C&R angling causes a generalized stress response, cold environments may mute or delay these effects and may also come with additional deleterious consequences, such as tissue freezing. Interestingly, reported mortality can be low following release but can be influenced by gear type, barotrauma, and hooking location. Postrelease behaviors and the spatial ecology of ice-angled fish are poorly understood, but technologies such as telemetry and biologgers and an intensification of research on the topic are starting to produce new insights in this area. As it stands, research on the consequences of winter C&R angling is largely restricted to a handful of popular sport fish species, and these consequences are likely

Fish that strike angling lures often have a set of characteristics that predispose them to capture. Vulnerable fish may then be removed from a population, either through harvest or incidental mortality, and in turn leave individuals in a population that are less vulnerable to angling. Over time, the removal of vulnerable individuals can erode capture rates, possibly resulting in evolutionary changes if traits that result in capture correlate with characteristics such as fecundity or growth. We sought to define the mechanisms driving individual angling vulnerability in Muskellunge Esox masquinongy, with the intent of informing management activities to conserve populations. The behavior of individually identified Muskellunge (n = 68; mean TL = 310.2 mm; range = 229–350 mm) was assessed using standard open‐field tests; the fish were then stocked into earthen‐bottom ponds to assess angling vulnerability. After angling, all captured fish and a subset of uncaptured fish were assessed for metabolic parameters. Results indicated that larger Muskellunge displaying low levels of exploration and aggression were preferentially captured. Behaviors such as boldness and activity did not influence capture, and metabolic parameters did not differ between captured and uncaptured fish.