Article

Can smartphones kill Trout? Mortality of memorable-sized Bull Trout (Salvelinus confluentus) after photo-releases

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Abstract

Mortality associated with catch-and-release (C&R) fisheries is typically estimated as a single value associated with fish that are immediately released after capture. However, with the widespread use of smartphones by anglers, memorable or rare fish may be subjected to prolonged handling time for photographs and measurements, resulting in increased air exposure and subsequent increased potential for post-release mortality. In situations of overfishing, large fish become rarer and their memorable status may increase. This may create a depensatory cycle of additional handling and mortality. The combination of mortality from prolonged handling, immediate release, and illegal harvest is a cumulative C&R-related cryptic mortality that may have population level effects in high-effort sport fisheries. We investigated the potential post-release mortality of memorable sized (average length of 60 cm) bull trout after simulating prolonged handling (involving photographing and measuring) and immediate release in a controlled angling study at a remote Albertan lake during summer. We found that handling time and air exposure of large bull trout subjected to photography and measurement was long (112 s) and associated post-release mortality was high (10 dead / 30 fish; 33 % after 24 h observation). Immediate release mortality was also high (3 dead / 20 fish; 15 %). These levels of mortality, combined with high angler effort, can potentially lead to population-scale declines at C&R fisheries. The complexity and difficulty of population-scale and field-level measurements of cryptic mortality suggest that adaptive management experiments in reductions in angling effort and improved fish handling may be effective in increasing understanding of sustainable angling.

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... Salmonid fishes are an important target of recreational fishers around the world, and the effects of C&R on salmonids has been the focus of extensive research in lake and lotic environments, particularly anadromous species making spawning migrations Joubert et al., 2020;Kerr et al., 2017;Lennox et al., 2015). In contrast, relatively few studies on C&R have looked at the biophysical responses of anadromous salmonids caught in coastal waters (Whitlock et al., 2016). ...
... Air exposure after extended fight times has been shown to increase mortality in O. mykiss and has been demonstrated to be a component of delayed mortality in bull trout Salvelinus confluentus (Suckley 1859) (Ferguson & Tufts, 1992;Joubert et al., 2020). It has also been shown to increase sublethal behavioural impacts in S. salar, measured as downstream movement after release (Thorstad et al., 2003). ...
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This study investigated the biophysical responses of sea run brown trout Salmo trutta to catch‐and‐release in the coastal fishery around Gotland, Sweden. It used information recorded on individual angled S. trutta (n = 162) including fight time, handling time, total air exposure time, injury, bleeding, fish length, body condition, spawning status, water temperature, hook location and difficulty of hook removal. Reflex action mortality predictors (equilibrium, operculum beats, tail grab response, body flex response, and vestibular‐ocular response), tests of blood glucose and lactate, and observation of hooking injury to measure the relative impact of the angling event on the fish's physical state and stress experienced. The results of this study suggest low rates of post release mortality and generally limited stress responses to angling events, and relatively high post release survival supported by the recapture of many tagged S. trutta. However, a number of scenarios were identified in which stress responses are likely to be compounded, and where anglers should take additional action to reduce sub‐lethal physiological disturbances and the risk of delayed mortality. Particular care should be taken to limit cumulative total air exposure to <10 s, reduce handling time, and risk of additional injury in angling events with extended fight times, when water temperatures >10 °C, or where S. trutta show evidence of being physically compromised by injury or having recently spawned. The results also indicate the importance of using appropriately sized single hooks, rather than larger treble hooks to reduce hooking injury and handling time during unhooking. This article is protected by copyright. All rights reserved.
... This is reflected in the relationship between respondents favouring release of sea trout and a greater likelihood of them photographing the catch. However, taking a photo has the potential to negatively influence the success of the release through increased handling time and possibly increased air exposure if best practices are not followed (Cook et al., 2015;Joubert et al., 2020). Awareness of possible unintended negative impacts from photographing catches may be another important knowledge gap in this fishery, particularly for anglers that always or often photograph their catches of sea trout. ...
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... PDF p. 32: Under incidental harvest, note that post-release angling mortality can reach 33% from excessive handling and delayed release of large fish (Joubert et al. 2020). Also, it is claimed that scientific sampling is a low-risk threat. ...
Technical Report
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Catch-and-release recreational angling has become very popular as a conservation strategy and as a fisheries management tool for a diverse array of fishes. Implicit in catch-and-release angling strategies is the assumption that fish experience low mortality and minimal sub-lethal effects. Despite the importance of this premise, research on this topic has focused on several popular North American sportfish, with negligible efforts directed towards understanding catch-and-release angling effects on alternative fish species. Here, we summarise the existing literature to develop five general trends that could be adopted for species for which no data are currently available: (1) minimise angling duration, (2) minimise air exposure, (3) avoid angling during extremes in water temperature, (4) use barbless hooks and artificial lures/flies, and (5) refrain from angling fish during the reproductive period. These generalities provide some level of protection to all species, but do have limitations. Therefore, we argue that a goal of conservation science and fisheries management should be the creation of species-specific guidelines for catch-and-release. These guidelines would take into account the inter-specific diversity of fishes and variation in fishing techniques. As recreational angling continues to grow in popularity, expanding to many developing countries, and targeting alternative species, it is important that reasonable data appropriate for specific fish and fisheries are available. The sustainable use and conservation of recreational fishery resources will depend upon the development and dissemination of effective catch-and-release angling strategies based upon sound science to stakeholders around the world.
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In many parts of sub-Saharan Africa community water points are provided through external support in the form of enhanced boreholes fitted with hand pumps. The external agency supplying the improved water source commonly provides maintenance training and assists in organising a governance plan for the water point. Despite its apparent virtues the Village-Level Operation and Maintenance model still experiences high levels of water point failures, even where the technical training and material conditions are adequate. There has been relatively little investigation of the institutional factors that may influence the cases where villages successfully maintain their shared water source infrastructure. This research investigated five villages in central Malawi where communities had maintained their water point hand pumps for periods exceeding 10 years. The results point to the importance of informal institutions giving primacy to ad-hoc 'rules-in-use' that suit the local context, and adapting forms of free-rider sanctions that are typically minor, low level and triangulated with local norms and behaviours. The findings highlight collective action that is successful through day-to-day adaption and that serves to institutionalise cooperative behaviour through appeals to norms.
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Catch-and-release regulations are among the most common types of fishing regulations. In recent years, concerns have arisen regarding the exposure of fish to air during catch-and-release angling. The purpose of our study was to quantify the length of time angled fish were exposed to air by anglers in a typical catch-and-release fishery and relate it to the lengths of time reported to produce negative effects. In total, 312 individual anglers were observed on the South Fork Snake River, Idaho, from May through August 2016. Fight time varied from 1.1 s to 230.0 s, and average fight time was 40.0 s (SD=36.8). Total air exposure times varied from 0.0 s to 91.8 s and averaged 19.3 s (SD=15.0). Though not statistically significant, a trend in reduced fight times was observed when anglers were guided and increased air exposure times when a net was used and a picture was taken. Results of the current study suggest that anglers expose fish to air for periods that are much less than those reported to cause mortality.
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Previous research has shown that social sanctions can catalyze and buttress conservation efforts; however, it is unclear how willing people are to confront (e.g., express verbal or nonverbal approval or disapproval) environmental transgressions. In the present study, willingness to sanction was measured with respect to recycling. Results showed that there was an asymmetry between approval and disapproval. That is, while participants expressed approval for the commission of a positive conservation behavior (recycling), they did not express disapproval for the omission of the same behavior. When asked about their willingness to sanction, participants were more willing to reward than punish and more willing to impose subtle versus overt sanctions. Willingness to impose each type of social sanction was correlated with the perceived effectiveness of that sanction. Overall, results showed that students were hesitant to confront environmental transgressors with social sanctions. It is proposed that creating a culture of conservation requires a willingness to confront and that the hesitation to impose social sanctions is due to a lack of metanorms that support the sanctioning.
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The assumption that animals released from fishing gears survive has frequently been scrutinized by researchers in recent years. Mortality estimates from these research efforts can be incorporated into management models to ensure the sustainability of fisheries and the conservation of threatened species. Post-release mortality estimates are typically made by holding the catch in a tank, pen or cage for short-term monitoring (e.g. 48 h). These estimates may be inaccurate in some cases because they fail to integrate the challenges of the wild environment. Most obvious among these challenges is predator evasion. Stress and injury from a capture experience can temporarily impair physiological capacity and alter behaviour in released animals, a period during which predation risk is likely elevated. In large-scale commercial fisheries, predators have adapted their behaviour to capitalize on impaired fishes being discarded, while in recreational catch-and-release fisheries, exercise and air exposure can similarly impede the capacity for released fish to evade opportunistic predators. Owing to the indirect and often cryptic nature of this source of mortality, very few studies have attempted to document it. A survey of the literature demonstrated that <2% of the papers in the combined realms of bycatch and catch-and-release have directly addressed or considered post-release predation. Future research should combine field telemetry and laboratory studies using both natural and simulated predation encounters and incorporate physiological and behavioural endpoints. Quite simply, predation is an understudied and underappreciated contributor to the mortality of animals released from fishing gears.
Article
Over the past 20 years, there has been a dramatic increase in the use of physiological tools and experimental approaches for the study of the biological consequences of catch‐and‐release angling practices for fishes. Beyond simply documenting problems, physiological data are also being used to test and refine different strategies for handling fish such that stress is minimised and survival probability maximised, and in some cases, even for assessing and facilitating recovery post‐release. The inherent sensitivity of physiological processes means that nearly every study conducted has found some level of – unavoidable – physiological disturbance arising from recreational capture and subsequent release. An underlying tenet of catch‐and‐release studies that incorporate physiological tools is that a link exists between physiological status and fitness. In reality, finding such relationships has been elusive, with further extensions of individual‐level impacts to fish populations even more dubious. A focus of this article is to describe some of the challenges related to experimental design and interpretation that arise when using physiological tools for the study of the biological consequences of catch‐and‐release angling. Means of overcoming these challenges and the extrapolation of physiological data from individuals to the population level are discussed. The argument is presented that even if it is difficult to demonstrate strong links to mortality or other fitness measures, let alone population‐level impacts of catch‐and‐release, there remains merit in using physiological tools as objective indicators of fish welfare, which is an increasing concern in recreational fisheries. The overarching objective of this paper is to provide a balanced critique of the use of physiological approaches in catch‐and‐release science and of their role in providing meaningful information for anglers and managers.
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The sport fishery for walleyes Stizostedion vitreum in Alberta, Canada, has declined severely because of high angling pressure relative to the low productivity of northern fisheries. Following extensive public consultation, highly restrictive length and bag limits were implemented on all walleye fisheries, clearly increasing the opportunities and temptations for anglers to illegally harvest fish. An estimate of illegal harvest was derived from data gathered at 29 sport fisheries in Alberta from 1991 to 1998. The technique involved counting protected-length fish in anglers' creels and comparing these numbers to the numbers of protected-length fish released. I avoided anglers' exaggeration of released walleye numbers by comparing the ratios of the lengths of fish caught by test angling to those of fish retained and reported by anglers, as recorded by creel clerks. The average illegal harvest level was high; 18.4% (range = 0.2–68.8%) of protected-length walleyes caught were kept. Illegal harvest was lowest at fisheries with catch-and-release regulations and highest at fisheries managed with slot-length limits. Of particular importance to fisheries managers, illegal harvest was inversely related to catch rate, thereby creating a strong depensatory response to a fishery decline. Other indices of compliance (creel clerks' reports of illegal harvest, the percentage of protected-length fish in anglers' creels, and angler infraction rates) were less useful indicators of illegal harvest. To counteract the negative effects of illegal harvest, managers should (1) avoid using length limits at lakes expected to have high illegal harvest levels, (2) use slot-length limits only at lakes where catch rates are expected to be high, and (3) not rely on low infraction rates or low percentages of protected-length fish in creels to imply high levels of compliance.
Article
Length‐limit regulations and promotion of catch‐and‐release fishing have become increasingly important management approaches for recreational fisheries. We review‐studies on catch‐and‐release (hooking) mortality gathered from the existing fisheries literature and from a survey of fisheries management agencies in all 50 states, the U.S. government, all Canadian provinces, and selected academic and research institutions. We identified hooking mortality estimates for 32 taxa. Most studies dealt with salmonids, centrarchids (especially black basses, Micropterus spp.), and percids (especially walleye, Stizostedion vitreum). Within and among species, differences in percent mortality were reported in association with bait type (artificial vs. natural), hook type (number of hooks, hook size, and barbs), season/ temperature, water depth (depressurization), anatomical location of hook wound, and individual size. Although most hooking mortalities occur within 24 h, the use of initial plus delayed mortality provides a more complete estimate of mortality. Single hooks (especially when used in conjunction with natural baits) resulted in higher mortalities than treble hooks. Environmental conditions (notably high water temperature and low dissolved oxygen) are important to overall mortality related to hooking, playing, and handling. Mortalities were highly variable; occasionally exceeding 30% among red drum (Sciaenops ocellatus), smallmouth bass (M. dolomieu), largemouth bass (M. salmoides), cutthroat trout (Oncorhynchus clarki), and catfishes (Ictaluridae), and 68% among spotted seatrout (Cynoscion nebulosus), bluegills (Lepomis macrocbirus), crappies, (Pomoxis spp.), striped bass (Morqne saxatilis), and coho salmon (O. kisutch). Lake trout (Salvelinus namaycush) and pikes (Esoddae) had mortalities under 15%. The many variables potentially affecting hooking mortality may make optimal management of particular species and water bodies difficult using regional‐level (e.g., statewide) management regulations.
Article
Most research on catch-and-release (C&R) in recreational fishing has been conducted from a disciplinary angle focusing on the biological sciences and the study of hooking mortality after release. This hampers understanding of the complex and multifaceted nature of C&R. In the present synopsis, we develop an integrative perspective on C&R by drawing on historical, philosophical, socio-psychological, biological, and managerial insights and perspectives. Such a perspective is helpful for a variety of reasons, such as 1) improving the science supporting successful fisheries management and conservation, 2) facilitating dialogue between managers, anglers, and other stakeholders, 3) minimizing conflict potentials, and 4) paving the path toward sustainable recreational fisheries management. The present work highlights the array of cultural, institutional, psychological, and biological factors and dimensions involved in C&R. Progress toward successful treatment of C&R might be enhanced by acknowledging the complexity inherent in C&R recreational fishing.
Article
The bull trout Salvelinus confluentus is believed to be among the most thermally sensitive species in coldwater habitats in western North America. We conducted a comprehensive field assessment of thermal habitat associations throughout the southern margin of the species' range. We developed models of thermal habitat associations using two data sets representing a geographically diverse range of sites and sampling methods. In both data sets, maximum temperature was strongly associated with the distribution of bull trout. In spite of the potential biases in these data sets, model predictions were similar. In both cases, the probability of the occurrence of bull trout exceeded 50% when the maximum daily temperature was less than 14-16°C, a result that is consistent with recent laboratory-based thermal tolerances. In one data set, we modeled the association between the distribution of bull trout and environmental variables, including temperature, instream cover, channel form, substrate, and the abundance of native and nonnative salmonid fishes. Only temperature was strongly associated with the distribution of bull trout. Our results and related studies of landscape habitat associations suggest that conservation efforts for bull trout would benefit from a focus on maintaining and restoring large and interconnected coldwater habitats.
Article
A length-categorization system was developed to assess structure of fish stocks with greater precision than is possible using Proportional Stock Density (PSD). Three new size categories - preferred, memorable, and trophy - were developed to accompany previously established stock and quality lengths. Like minimum stock and quality lengths, minimum lengths for the new categories are defined as percentage lengths of the all-tackle, world-record fish. Length ranges from or near which minimum stock, quality, preferred, memorable, and trophy lengths should be selected were computed for all freshwater fish species having a world-record length listed by the International Game Fish Association in 1982. Minimum lengths corresponding to each of the five size categories are proposed for several species. By arraying samples of fish population data or angler catch data according to the five size-group categories, a length-frequency distribution can be easily assessed and verbalized. Relative Stock Density (RSD) or models for catch rates also can be developed to set management objectives that are easily understandable, yet reflect recruitment, mortality, and growth functions of fish populations and communities. Desirable percentages and catch rates for size-group categories may differ among individual waters or geographic regions depending upon management objectives and the capacity to produce the species of interest.
Article
Few studies have assessed catch-and-release mortality of salmonids at water temperatures of 23 degrees C or above, despite predictions of warming stream temperatures due to climate change. The primary objective of this study was to measure the catch-and-release mortality of rainbow trout Oncorhynchus mykiss, brown trout Salmo trutta, and mountain whitefish Prosopium williamsoni in three water temperature treatments, namely, when daily maximum water temperatures were cool (<20 degrees C), warm (20-22.9 degrees C), and hot (>= 23 degrees C). A secondary objective was to assess the catch-and-release mortality of salmonids angled in morning and evening within the water temperature treatments. These objectives were related to Montana Fish, Wildlife and Parks' drought fishing closure policy. Angling (fly-fishing only) occurred in the Gallatin and Smith rivers. All angled fish were confined to in-stream holding cages and monitored for mortality for 72 h. Mortality of rainbow trout peaked at 16% in the Gallatin River and 9% in the Smith River during the hot treatment. Mortality of brown trout was less than 5% in all water temperature treatments in both rivers. Mountain whitefish mortality peaked at 28% in the hot treatment in the Smith River. No mortality for any species occurred in either river when daily maximum water temperatures were less than 20 degrees C. Mortality of rainbow trout peaked at 16% in the evening hot treatment in the Smith River. Mortality rates of brown trout and mountain whitefish were not related to time of day. The catch-and-release mortality rates presented here probably represent fishing mortality given that most anglers in southwestern Montana practice catch-and-release angling. The mortality values we observed were lower than predicted (<30%) given reports in the literature. The difference is probably related to the in situ nature of the study and periods of cooler water temperatures between peaks, which facilitated recovery from thermal stress.
Article
We searched major electronic databases to identify peer-reviewed literature investigating the role of temperature on the stress response and mortality of captured and released fish. We identified 83 studies that fit these criteria, the majority of which were conducted in North America (81%) on freshwater fish (76%) in the orders Perciformes (52%) and Salmoniformes (28%). We found that hook-and-line fisheries (65% of all studies) were more commonly studied than all net fisheries combined (24%). Despite the wide recognition for many species that high water temperatures exacerbate the effects of capture on released fish, this review is the first to quantitatively investigate this problem, finding that warming contributed to both mortality and indices of stress in 70% of articles that measured each of those endpoints. However, more than half (58%) of the articles failed to place the experimental temperatures into a biological context, therefore limiting their broad applicability to management. Integration of survival and sublethal effects to investigate mechanisms of fish mortality was relatively rare (28%). Collectively, the results suggest that capture–release mortality increases at temperatures within, rather than above, species-specific thermal preferenda. We illustrate how knowledge of ecologically relevant high temperatures in the capture and release of fish can be incorporated into management, which will become increasingly important as climate change exerts additional pressure on fish and fisheries.
Article
a b s t r a c t Research on a wide range of fish species has revealed that deep hooking is perhaps the single most important determinant of injury and post-release mortality in recreational fisheries. However, there is little information on the best option for dealing with deeply hooked fish that are to be released; should the line be cut or should the hook be removed? Using bluegill sunfish (Lepomis macrochirus) as a model we investigated sublethal (e.g., swimming performance, physiological condition, injury levels) and lethal consequences associated with removal of deeply ingested hooks versus cutting the line and leaving the hook embedded in the esophagus, relative to shallowly hooked controls. Neither hook retention nor deep hook-removal altered the swimming performance of the fish in this study relative to controls. However, there was evidence of short-term physiological disturbance. For example, hematocrit was reduced for fish that had hooks removed, consistent with visual observations of bleeding. In addition, blood glucose levels tended to be higher and plasma Na + levels tended to be lower in deeply hooked fish that had hooks removed indicating stress and ionic imbalance even 24 h after capture. During holding experiments we noted the highest mortality levels in fish for which the hook was removed (33% after 48 h and 44% after 10 days). Mortality rates were lowest for the controls (0% after 48 h and 4% after 10 days) and intermediate for the line-cut treatment (8% after 48 h and 12.5% after 10 days). After 48 h, 45.5% of the fish from the line-cut treatment group were able to expel the hook originally embedded in their esophagus, and at the end of the 10 day study, 71.4% had expelled the hook. Even with the hook left in the esophagus, fish were able to feed although at lower rates than controls during the first 48 h of holding. By 10 days post-capture, there were no differences in feeding rates as evidenced by growth patterns among the treatment groups, nor were there differences in the hepatosomatic index. Collectively, the findings from this study demonstrate that cutting the line is a more effective release method than removing the hook when fish are deeply hooked. As such, angler education efforts should focus on disseminating this message to anglers as well as encouraging the use of gear and techniques that minimize incidences of deep hooking (e.g., circle hooks, non-organic bait).
Article
Relative body size has long been recognized as a factor influencing repro-ductive success in fishes, but maternal age has only recently been considered. We monitored growth and starvation resistance in larvae from 20 female black rockfish (Sebastes melan-ops), ranging in age from five to 17 years. Larvae from the oldest females in our experiments had growth rates more than three times as fast and survived starvation more than twice as long as larvae from the youngest females. Female age was a far better predictor of larval performance than female size. The apparent underlying mechanism is a greater provisioning of larvae with energy-rich triacylglycerol (TAG) lipids as female age increases. The volume of the oil globule (composed primarily of TAG) present in larvae at parturition increases with maternal age and is correlated with subsequent growth and survival. These results suggest that progeny from older females can survive under a broader range of environmental conditions compared to progeny from younger females. Age truncation commonly induced by fisheries may, therefore, have severe consequences for long-term sustainability of fish populations.
Article
Abstract The practice of catch and release (CR) as a fisheries management tool to reduce fishing mortality is widely applied in both freshwater and marine fisheries, whether from shifts in angler attitudes related to harvest or from the increasing use of harvest restrictions such as closed seasons or length limits. This approach assumes that for CR fishing policies to benefit the stock, CR will result in much lower mortality than would otherwise occur. There are many challenges in the design of CR studies to assess mortality, and in many practical settings it is difficult to obtain accurate and precise estimates. The focus of this article is on the design and quantitative aspects of estimating CR mortality, the need for a comprehensive approach that explicitly states all components of CR mortality, and the assumptions behind these methods. A general conceptual model for CR mortality that is applicable to containment and tagging-based studies with a slight modification is presented. This article reviews the design and analysis of containment and tagging studies to estimate CR mortality over both the short and long term and then compares these two approaches. Additionally, the potential population-level impacts of CR mortality are discussed. A recurring theme is the difficulty of designing studies to estimate CR mortality comprehensively and the need for additional research into both statistical model development and field study design.
Article
The literature on common property-based resource management comprises many important studies that seek to specify the conditions under which groups of users will self-organize and sustainably govern resources upon which they depend. Using three of the more comprehensive such studies, and with an extensive review of writings on the commons, this paper demonstrates that the enterprise of generating lists of conditions under which commons are governed sustainably is a flawed and impossibly costly research task. For a way out, the paper examines the relative merits of statistical, comparative, and case study approaches to studying the commons. It ends with a plea for careful research design and sample selection, construction of causal mechanisms, and a shift toward comparative and statistical rather than single-case analyses. Such steps are necessary for a coherent, empirically-relevant theory of the commons.
Article
At present, there is a reasonable understanding of the independent effects of catch-and-release (C&R) angling stressors, such as air exposure and water temperature, on endpoints such as physiological disturbance, behavioural impairment and mortality. However, little is known about the multiplicative or interactive nature of these different C&R stressors. This study used bluegill (Lepomis macrochirus) as a model to evaluate the combined effects of water temperature and air exposure on fish behaviour, equilibrium status and short-term mortality following C&R. Experiments were replicated over 3 days with different ambient water temperatures (18.3, 22.8 and 27.4 °C). On each day, fish were captured by standard angling techniques, exposed to a range of air exposure durations (0, 30, 60, 120, 240, 480 and 960 s), and subsequently monitored for behavioural changes (within the first 300 s) and short-term (48 h) delayed mortality. Additional fish were captured by seine net for use as controls. There was an interactive effect of temperature and air exposure, whereby fish exposed to the highest temperature and longer air exposure durations lost equilibrium more often and had depressed ventilation rates relative to fish exposed to minimal air exposure and the lowest temperature. Immediate mortality at the lowest temperatures was negligible. However, significant delayed mortality (up to 80%) was noted at the highest water temperature (27.4 °C) in fish exposed to the three longest air exposure groups. In addition, at 27.4 °C, mortality among fish exposed to 480 and 960 s occurred at a faster rate than in any other treatment group. These results indicate that at low to moderate water temperatures, extended air exposure for bluegill may result in little mortality. However, at high water temperatures, short-term mortality (within 48 h) can be substantial, especially for fish that experience extended air exposure durations. Anglers and managers must recognize that C&R stressors can interact to have more dire consequences than when applied independently.
Article
This study challenges the oversimplified way in which abstract and bureaucratic 'design principles' derived from resource management literature are translated into development policy and practice, in pursuit of robust and enduring institutions. Drawing on research in the Usangu Basin, Tanzania, it explores the socially embedded nature of institutions for common property resource management and collective action. The concept of 'institutional bricolage' is outlined; a process by which people consciously and unconsciously draw on existing social and cultural arrangements to shape institutions in response to changing situations. Contrary to much theory, this study shows that institutions formed through bricolage are a dynamic mixture of the 'modern' and 'traditional', 'formal' and 'informal'.
Article
Sustained swimming at 0.9 BL s(-)(1), where BL is fork body length, following a bout of exhaustive exercise enhanced recovery of metabolite and acid-base status in rainbow trout compared with fish held in still water. The most striking effect of an active recovery was a total absence of the elevation cortisol concentration typically associated with exhaustive exercise. In fish swimming at 0. 9 BL s(-)(1), plasma cortisol levels averaged 20-25 ng ml(-)(1) throughout the 6 h recovery period. In contrast, plasma cortisol increased to a peak level of 128.4+/-11.2 ng ml(-)(1) (mean +/- s.e. m., N=6) in fish recovering in still water. Muscle glycogen was completely resynthesized and lactate cleared within 2 h of exercise in swimming fish compared with more than 6 h required in the fish held in still water. Similarly, blood lactate level and acid-base status were restored more quickly in the swimming fish. These observations suggest that the prolonged recovery usually associated with exhaustive exercise in rainbow trout is due to elevations in plasma cortisol concentration and that the stimulus for cortisol release is not exercise per se, but rather post-exercise inactivity.
Bull Trout Conservation Management Plan 2012-17. Alberta Sustainable Resource Development, Species at Risk Conservation Management Plan No
ASRD, 2012. (Alberta Sustainable Resource Development). Bull Trout Conservation Management Plan 2012-17. Alberta Sustainable Resource Development, Species at Risk Conservation Management Plan No. 8. Edmonton, AB. pp. 90 pp.
Standards for the Ethical Use of Fishes in Alberta
AESRD, 2013. Standards for the Ethical Use of Fishes in Alberta. Retrieved December 2018. https://open.alberta.ca/dataset/a14f1a76-6ba7-4df8-99e4-b7fc489f5f46/ resource/8eae46f1-4067-4046-83ef-50c88629ebd0/download/standardethicaluseoffishesinalberta-may2013a.pdf.