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Climate change

Western University

Physiology

Publication Year

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Full-Text Articles in Life Sciences

The Effect Of Dietary Thiaminase On Cardiac Function And Morphology In Lake Trout (Salvelinus Namaycush), Peter Baker Jun 2023

The Effect Of Dietary Thiaminase On Cardiac Function And Morphology In Lake Trout (Salvelinus Namaycush), Peter Baker

Electronic Thesis and Dissertation Repository

Thiamine deficiency from the consumption of invasive, high-thiaminase prey fishes is considered to be a major barrier for lake trout restoration in the Great Lakes. In fishes, an understudied aspect of thiamine deficiency is its effect on cardiac function. I examined the effects of dietary thiaminase on cardiac function and morphology in lake trout, specifically as they relate to thermal tolerance. Two hatchery strains of lake trout (Seneca and Slate) were raised on a control or thiaminase diet for nine months. The thiaminase diet was associated with significant ventricle enlargement, impaired cardiac function, and reduced thermal tolerance; these effects were …


Temperature-Dependent Developmental Plasticity In The Cardiorespiratory System Of Atlantic Salmon, Carlie A. Muir Mar 2022

Temperature-Dependent Developmental Plasticity In The Cardiorespiratory System Of Atlantic Salmon, Carlie A. Muir

Electronic Thesis and Dissertation Repository

Anthropogenic climate change is expected to have pervasive impacts on the performance and viability of fishes, as increasing temperatures create aerobically constrained environments for many species. Given the rapid rates of projected temperature increases, it is critical to evaluate the capacity for fish to respond to a changing thermal environment through phenotypic plasticity. In this thesis, I examined the capacity for developmental plasticity in the thermal performance of juvenile Atlantic salmon (Salmo salar) reared under two thermal regimes from fertilization, and investigated potential mechanistic underpinnings within the cardiorespiratory system. Cardiac performance was examined using a noninvasive Doppler echocardiograph …


Effects Of Elevated Temperature And Elevated Co2 On Leaf Carbon Fluxes In Boreal Conifers: Lab And Field Studies, Mirindi Eric Dusenge Oct 2019

Effects Of Elevated Temperature And Elevated Co2 On Leaf Carbon Fluxes In Boreal Conifers: Lab And Field Studies, Mirindi Eric Dusenge

Electronic Thesis and Dissertation Repository

Rising CO2 may warm northern latitudes up to 10 °C by the end of the century. However, responses of plant physiological processes (such as photosynthesis and respiration) and growth to climate change remain uncertain. Seedlings and mature trees of tamarack (a deciduous species) and black spruce (an evergreen species), North America dominant conifers, were exposed to combined warming (up to +9 ˚C) and elevated CO2 (up to +300 ppm). In seedlings, stomatal conductance (gs) tended to increase with warming in tamarack seedlings, while gsdeclined with warming in spruce. In both species, CO2 had …


Thermal Performance Covaries With Environmental Temperature Across Populations Of Atlantic Salmon (Salmo Salar), Kayla J. Harding Gradil Jun 2015

Thermal Performance Covaries With Environmental Temperature Across Populations Of Atlantic Salmon (Salmo Salar), Kayla J. Harding Gradil

Electronic Thesis and Dissertation Repository

Global climate change is projected to have widespread effects that could threaten the viability of natural populations. Physiological processes of aquatic ectotherms critically depend on their thermal environment, such that the optima for performance often correspond to environmental temperatures. Given predicted changes in aquatic thermal environments, it is increasingly important to understand organism’s underlying physiological mechanisms utilized to cope with these changes. Here, I show that three populations of Atlantic salmon (Salmo salar) are narrowly adapted to their native summer temperatures, such that thermal tolerance is optimized near average temperatures and collapses near peak temperatures. Further, I found …