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Dive into the research topics where Andy J. Danylchuk is active.

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Featured researches published by Andy J. Danylchuk.


Comparative Biochemistry and Physiology A-molecular & Integrative Physiology | 2012

The physiological response of the Caribbean reef shark (Carcharhinus perezi) to longline capture

Edward J. Brooks; John W. Mandelman; Katherine A. Sloman; Stephanie A. Liss; Andy J. Danylchuk; Steven J. Cooke; Gregory B. Skomal; David P. Philipp; David W. Sims; Cory D. Suski

Longline fishing is the most common elasmobranch capture method around the world, yet the physiological consequences of this technique are poorly understood. To quantify the sub-lethal effects of longline capture in the commonly exploited Caribbean reef shark (Carcharhinus perezi), 37 individuals were captured using standard, mid-water longlines. Hook timers provided hooking duration to the nearest minute. Once sharks were landed, blood samples were taken and used to measure a suite of physiological parameters. Control data were obtained by sampling an additional three unrestrained Caribbean reef sharks underwater at an established shark feeding site. The greatest level of physiological disruption occurred after 120-180min of hooking, whereas sharks exposed to minimal and maximal hook durations exhibited the least disturbed blood chemistry. Significant relationships were established between hooking duration and blood pH, pCO(2), lactate, glucose, plasma calcium and plasma potassium. Longline capture appears more benign than other methods assessed to date, causing a shift in the stress response from acute at the onset of capture to a sub-acute regime as the capture event progresses, apparently facilitating a degree of physiological recovery. Continued investigation into the physiological response of elasmobranchs to longline capture is vital for the effective management of such fisheries.


Conservation Physiology | 2014

Hooking injury, physiological status and short-term mortality of juvenile lemon sharks (Negaprion bevirostris) following catch-and-release recreational angling

Andy J. Danylchuk; Cory D. Suski; John W. Mandelman; Karen J. Murchie; Christopher R. Haak; Annabelle Brooks; Steven J. Cooke

Juvenile lemon sharks were angled and hooking injury, physiological stress, reflex impairment and short-term post-release mortality were quantified. Fight time was correlated with the level of physiological disturbance, but not post-release mortality. Four sharks (12.5%) died following release, and mortality was related to water temperature and body size.


Fisheries | 2015

Action Cameras: Bringing Aquatic and Fisheries Research into View

Daniel P. Struthers; Andy J. Danylchuk; Alexander D. M. Wilson; Steven J. Cooke

Digital action cameras (ACs) are increasingly being utilized for aquatic research purposes due to their cost effectiveness, versatility, high-resolution imagery, and durability. Here we review the advantages of AC technology in research, with particular emphases on (a) research videography (both in the field and the laboratory), (b) animal-borne studies, and (c) outreach and education purposes. We also review some of the limitations of this technology as represented by environmental factors (e.g., depth, turbidity) and deployment considerations (e.g., lens choices, imaging settings, battery life). As AC technologies evolve in response to growing public interest in their application versatility, researchers are indirectly reaping the rewards, with technological advances that are innovative, cost-effective, and can withstand frequent use in dynamic and rugged field conditions. With such a diversity of options available, future usefulness of ACs in research will only be limited by the creativity of the scien...


Conservation Biology | 2011

Engaging the Recreational Angling Community to Implement and Manage Aquatic Protected Areas

Andy J. Danylchuk; Steven J. Cooke

Recreational angling is a popular leisure activity, the quality of which is greatly dependent on fish abundance and well-functioning aquatic ecosystems. Aquatic protected areas (APAs) are used to help maintain and even restore aquatic systems and their associated biota, including fish species that are popular with recreational anglers. Paradoxically, the use of APAs has been a source of much contention and conflict between members of the recreational angling community and those interested in or mandated to protect aquatic resources on the basis of the interests of multiple stakeholder groups. The angling community is concerned about the loss of fishing opportunities and effectiveness of APAs. Although it is still unclear whether establishment of APAs alone can effectively protect aquatic resources, actively including the recreational angling community in the design, implementation, and management of APAs will help ensure the values of this rather substantial user group are incorporated into aquatic conservation strategies. Conversely, the probability of increasing the sustainability of recreational angling and related economies will be greatest if recreational angler groups remain open minded to both short-term and long-term goals of fisheries conservation strategies, including the use of APAs.


Journal of Fish Biology | 2010

Is there a need for a '100 questions exercise' to enhance fisheries and aquatic conservation, policy, management and research? Lessons from a global 100 questions exercise on conservation of biodiversity

Steven J. Cooke; Andy J. Danylchuk; Michel J. Kaiser; M. A. Rudd

Recent global and regional exercises have been undertaken to identify 100 questions of relevance to policy makers that, if answered, would improve decision making and conservation actions. These were intentionally broad, but all included themes and questions of relevance to aquatic and fisheries professionals (e.g. exploitation, habitat alteration, effectiveness of protected areas, migratory connectivity and environmental effects of aquaculture). Here, the content of the global 100 question exercise relevant to aquatic and fisheries issues is summarized and a critical analysis is provided. Many of the questions addressed in apparently unrelated themes and topics (e.g. terrestrial, agriculture and energy policy) have potential relevance to fisheries and aquatic habitats, which underlines the connectivity between terrestrial and aquatic realms. Given the intimate link between aquatic environmental problems and human activities (including culture and economics), greater understanding of the human dimension is required to inform decision making. Stakeholder perspectives need to be included as a core component of the fisheries management triangle (i.e. managing fish, habitat and people). The benefits and risks of conducting a global 100 questions exercise with an exclusive focus on questions of relevance to fisheries and aquatic practitioners are also considered. There is no question that evidence-based approaches to conservation are essential for addressing the many threats that face aquatic ecosystems and reverse the imperilment trends among ichthyofauna. It is still unclear, however, as to the extent to which 100 questions exercises will help to achieve conservation and management targets for aquatic resources. A global 100 questions exercise that focused on fisheries and aquatic issues would certainly help to generate interest and awareness sufficient to justify such an exercise.


Journal of Fish Biology | 2010

Chemical excretions of angled bonefish Albula vulpes and their potential use as predation cues by juvenile lemon sharks Negaprion brevirostris

Lorna J. Dallas; Aaron D. Shultz; A. J. Moody; Katherine A. Sloman; Andy J. Danylchuk

Bonefish Albula vulpes (n = 7) exercised to exhaustion and air exposed for 1 min as part of a catch-and-release angling event were found to excrete both ammonia and urea, but cortisol and lactate were below detectable levels. Urea made up a greater proportion of total nitrogen excretion from these fish at all time points following an angling event. When captive juvenile lemon sharks Negaprion brevirostris (n = 12) were exposed to a 30 s pulse of these chemicals [ammonia (500 mM), cortisol (20 µg l(-1) ), lactate (6 mM) or urea (3 mM)], they showed a significant reduction in the frequency of resting behaviours when exposed to ammonia and urea than when exposed to control water. It appears that products excreted by A. vulpes, particularly ammonia and urea, may provide an olfactory cue for the post-release predation of A. vulpes by N. brevirostris during catch-and-release angling events.


Reviews in Fisheries Science & Aquaculture | 2015

Status of Recreational Fisheries in India: Development, Issues, and Opportunities

Nishikant Gupta; Shannon D. Bower; Rajeev Raghavan; Andy J. Danylchuk; Steven J. Cooke

Recreational fishing is an established activity in developed countries across the world. Many emerging economies have well-established recreational fisheries; however, in countries such as India there has been little discourse on what is needed to support this activitys sustainable development. Here, we review the history of recreational fishing and the current status of recreational fisheries in India. The lack of scientific knowledge on the basic biology of sport fish species, targeting of threatened species, and the absence of region- or species-specific angling regulations for recreational fisheries are identified as some of the challenges associated with this sector in India. Moreover, governance structures are disorganized, with multiple agencies assuming some responsibility for recreational fishing but none tasked explicitly with its sustainable development and management. With improved legislative support and a clear policy framework, developing a responsible and sustainable recreational fisheries industry in India is possible.


Oecologia | 2017

Spatiotemporal drivers of energy expenditure in a coastal marine fish

Jacob W. Brownscombe; Steven J. Cooke; Andy J. Danylchuk

Animal behavior and energy expenditure often vary significantly across the landscape, and quantifying energy expenditure over space and time provides mechanistic insight into ecological dynamics. Yet, spatiotemporal variability in energy expenditure has rarely been explored in fully aquatic species such as fish. Our objective was to quantify spatially explicit energy expenditure for a tropical marine teleost fish, bonefish (Albula vulpes), to examine how bonefish energetics vary across landscape features and temporal factors. Using a swim tunnel respirometer, we calibrated acoustic accelerometer transmitters implanted in bonefish to estimate their metabolic rates and energy expenditure, and applied this technology in situ using a fine-scale telemetry system on a heterogeneous reef flat in Puerto Rico. Bonefish energy expenditure varied most among habitats, with significant interactions between habitat and temporal factors (i.e., diel period, tide state, season). The energy expenditure was generally highest in shallow water habitats (i.e., seagrass and reef crest). Variation in activity levels was the main driver of these differences in energy expenditure, which in shallow, nearshore habitats is likely related to foraging. Bonefish moderate energy expenditure across seasonal fluctuations in temperature, by selectively using shallow nearshore habitats at moderate water temperatures that correspond with their scope for activity. Quantifying how animals expend energy in association with environmental and ecological factors can provide important insight into behavioral ecology, with implications for bioenergetics models.


The Journal of Experimental Biology | 2016

Swimming activity and energetic costs of adult lake sturgeon during fishway passage.

Jason D. Thiem; Jeff W. Dawson; Daniel Hatin; Andy J. Danylchuk; Pierre Dumont; Adrian C. Gleiss; Rory P. Wilson; Steven J. Cooke

ABSTRACT Fish migrations through riverine systems can be energetically demanding, and the presence of fishways to facilitate upstream passage can add an additional energetic cost that may directly affect fitness. Successful fishway passage is a function of the ability of fish to select appropriate paths and swimming strategies that do not exceed their swimming capacity. Triaxial accelerometers were used to estimate the energetic expenditure of adult lake sturgeon (Acipenser fulvescens) swimming through a vertical slot fishway, to determine whether individual behaviour or path selection, resulting in differences in cumulative energy use, explain fishway passage success. Most individuals attempted to pass the fishway (n=30/44; 68%), although successful passage only occurred for a subset of those attempting (n=7/30; 23%). High-speed swimming was rarely observed during upstream passage through fishway basins, and was of short duration. Two turning basins delayed passage, subsequently resulting in a higher energetic cost. The rate at which energy was expended did not differ among successful and unsuccessful individuals, although successful sturgeon exhibited higher costs of transport (42.75 versus 25.85 J kg−1 m−1). Energy expenditure metrics were not predictive of successful fishway passage, leading us to conclude that other endogenous or exogenous factors influence passage success. In a practical application of field measurements of energy expenditure, we demonstrate that fishway passage through a structure designed to facilitate migration does result in an energetic loss for lake sturgeon (3249–16,331 J kg−1), equivalent to individuals travelling 5.8–28.2 km in a lentic system. Highlighted Article: Adult sturgeon energy use during fishway passage reveals location-specific differences in energy use and variable overall net energy costs.


BioScience | 2011

Sustainable “Seafood” Ecolabeling and Awareness Initiatives in the Context of Inland Fisheries: Increasing Food Security and Protecting Ecosystems

Steven J. Cooke; Karen J. Murchie; Andy J. Danylchuk

The sustainable seafood movement has adopted a variety of certification and ecolabeling systems, as well as seafood-awareness campaigns, to influence industry and help consumers make informed decisions regarding their seafood consumption. However, a review of these programs revealed that the majority are focused on marine and coastal fisheries. Globally, freshwaters and their fish assemblages represent some of the most threatened systems and taxa because of multiple anthropogenic stressors. There is an urgent need to harness the momentum of the sustainable seafood movement for marine systems to benefit all aquatic systems, including freshwater. Moreover, given that freshwater systems are at particular risk in developing countries in which small-scale fisheries dominate, it is essential to expand awareness campaigns, through grassroots initiatives that differ significantly from current awareness campaigns that are global in focus, involve industrialized large-scale fisheries, and assume significant exports of seafood. Addressing the limitations of marine campaigns is a logical first step before launching new programs aimed at inland fisheries. In the long term, failure of the sustainable seafood movement to incorporate freshwater fisheries will lead to public perception that these fisheries are not in peril and may allow unsustainable practices to continue.

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Tony L. Goldberg

University of Wisconsin-Madison

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Christopher R. Haak

University of Massachusetts Amherst

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