Katrina Cook, PhD
Current Research
Mortality of Pacific salmon released from commercial fisheries
Commercial fisheries for Pacific salmon in BC target abundant species but also often inadvertently capture other populations or species that may not be of sufficient abundance to support exploitation. This 'bycatch' is released as a conservation strategy. For this approach to be effective, the mortality of released fish must be quantified and if substantial, reduced. A large component of my current research is to work with industry, government, and NGO's to evaluate this mortality and how it varies among handling regimes, gear types, populations, and capture locales.
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Featured Publication: Population-specific mortality in coho salmon (Oncorhynchus kisutch) released from a purse seine fishery
Molecular and physiological responses to capture stress in Pacific salmon
From a rapid non-lethal collection of blood and/or gill tissue, I can quantify responses to and recovery from capture scenarios at multiple levels of biological organization. Genomics is the study of groups of genes, their functions, and how they respond to changes. In terms of physiology I measure indicators of stress, exhaustion, and osmoregulatory status. I aim to use these tools to characterize differences among populations, potentially identifying why some are more affected by capture stress than others, and to understand how the basic physiological changes occurring through migration influence responses to capture stress.
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Human Dimensions of Bycatch Mortality in Commercial Salmon Fisheries
Because much of my research has direct applications to fisheries management, I incorporate human dimensions research, interviewing commercial salmon fishers regarding their perspectives on the release of non-target salmon. This approach allows for direct knowledge transfer with resource users, but is also an opportunity for fishers to contribute practical information. Specifically, I am interested in understanding the perceived rates of post-release mortality and means to reduce mortality released fish.
Featured publication: Bycatch mortality of endangered coho salmon: Impacts, solutions, and aboriginal perspectives
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Using bioenergetics to inform harvest decisions in terminal fisheries for Pacific salmon
Terminal fisheries, conducted near the end of a stock's spawning migration, are a sustainable harvest option for Pacific salmon because they can avoid non-target stocks. However, energy is diverted from muscle to gonads with maturation in Pacific salmon, reducing product quality. Lacking is knowledge of temporal dynamics of energy utilization during maturation, which is critical to maximize both product quality and value in terminal fisheries. In collaboration with Lake Babine and Sts'ailes First Nations, we are assessing the temporal and spatial dynamics of energy usage as fish approach terminal areas, how this affects flesh quality and colour, and how these processes differ among locations and target stocks. Results will inform where and when harvests should occur.
Previous Research
Neutrally-buoyant External Tag
Telemetry and Tag Effects Research
As a Research Associate within the Ecology Group of the Pacific Northwest National Laboratory, I worked on several large-scale tag effects research initiatives assessing the most effective and least damaging methods to implant acoustic tags. I also participated in a field evaluation of a neutrally buoyant externally affixed acoustic transmitter for juvenile salmonids that may be exposed to barotrauma during downstream passage through dam turbines. In addition to this tag effects research, we also used radio-telemetry to determine spawning and overwintering habitats in the Sanpoil River of Northern WA.
Featured publication: A Comparison of Implantation Methods for Large PIT tags of Injectable Acoustic Transmitters in Juvenile Chinook Salmon
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Barotrauma During Development in White Sturgeon
White sturgeon are known to drift downstream during development and in regulated rivers, this means they are likely exposed to dramatic changes in pressure if they pass over a dam, but the effects of this are unknown. As a Research Associate within the Ecology Group of the Pacific Northwest National Laboratory, decompression tests and radiography were used to determine at what point in development larval and juvenile white sturgeon may be impacted by the effects of barotrauma, such as would be encountered during downstream dam passage.
Featured publication: Vulnerability of larval and juvenile White Sturgeon to Barotrauma: Can they Handle the Pressure?
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Behavioural and Fitness Correlates of the Stress Response in wild fish
The stress response is an adaptive mechanism, but is energetically costly and there exists great inter-individual variability in the magnitude of response within a species. My M.Sc research within the Fish Ecology and Conservation Physiology Lab sought to understand the fitness and behavioural correlates of the stress response. In Pacific salmon, I found the stress response was associated with pre-spawn mortality among female pink salmon on the spawning grounds and migration failure upon river entry in sockeye salmon. I also determined that the stress response is repeatable within individual fish.
Featured publications:
2) The glucocorticoid stress response is repeatable between years in a wild teleost fish
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