Thermal ecology of freshwater fishes: the effects of variability in water temperature

水温是影响淡水鱼生理和生态的主要环境因素，淡水鱼是一类在加拿大及其他地区具有重要经济、文化和生态意义的生物。我的研究计划的长期目标是阐明水温及其与其他非生物和生物因素的相互作用如何影响淡水鱼的生物(行为、生存和繁殖)和种群(丰度和分布)生态。最近，很明显，为了充分了解温度如何影响淡水鱼(和任何其他生物)的生态，有必要调查它们对环境温度变化的反应。因此，在未来五年，我的目标是描述淡水环境温度的时空变异性，并确定淡水鱼对这种变异性的生态反应。为了解决这一短期目标，我提出了四个项目，将重点放在弗雷泽河分水岭(不列颠哥伦比亚省)，并将使用成年鲑鱼(红鲑鱼、牛鲑鱼和彩虹鲑鱼)作为模式物种。项目1将利用历史水温数据(自1950年以来收集)和光谱分析，量化弗雷泽河流域水温的时空变异性，并评估成年迁徙红鲑鱼变异性模式变化的潜在后果。项目2将利用成鱼迁徙的历史水温数据和现有的无线电遥测数据(自2002年以来约3,250条鱼)来检验这一假设，即迁徙过程中遇到的不同温度条件对心肺功能按温度呈现狭窄曲线的种群的个体存活率有更大的影响。项目3将使用红鲑鱼的田间和实验室实验来检验这一假设，即个体体温调节的有效性取决于其内部状态(例如生殖成熟、病原体负载、可用体能)。该项目还将检验有效的体温调节提高生殖成功的假设。项目4将使用现场和实验室对牛鲑鱼和彩虹鲑鱼的实验来研究水温和活动之间的关系，并测试在更不同种类的热生境中行为体温调节的能量成本最小的假设。这些项目将提高我们对淡水鱼对温度反应的认识和预测能力，并将在一个变暖和温度变化更大的世界中为它们的管理和保护提供信息。这些项目还将培训新一代HQP(5名UG、3名硕士、1名博士)，并使他们掌握进一步推进加拿大淡水鱼研究和养护所需的知识和技能。

Water temperature is a major environmental factor affecting the physiology and ecology of freshwater fishes — a group of organisms that are economically, culturally and ecologically important in Canada and beyond. The long-term objective of my research program is to elucidate how water temperature and its interaction with other abiotic and biotic factors influence the organismal (behaviour, survival and reproduction) and population (abundance and distribution) ecology of freshwater fishes. Recently, it has become clear that to fully understand how temperature influences the ecology of freshwater fishes (and any other organism) it is necessary to investigate their responses to variability in ambient temperature. Therefore, over the next five years, my objective is to characterize the spatio-temporal variability in temperature of freshwater environments and determine the ecological responses of freshwater fishes to that variability. To address this short-term objective, I propose four projects that will focus on the Fraser River watershed (British Columbia) and will use adult salmonids (sockeye salmon, bull trout and rainbow trout) as model species. Project 1 will use historical water temperature data (collected since 1950) and spectral analyses to quantify spatio-temporal variability in water temperature in the Fraser River watershed and assess the potential consequences of changes in variability patterns for adult migrating sockeye salmon. Project 2 will use the historical water temperature data and existing radio-telemetry data on adult migrating sockeye salmon (~3,250 fish since 2002) to test the hypothesis that variable thermal conditions encountered during migration have a greater impact on survival of individuals from populations that exhibit narrow curves of cardiorespiratory capacity by temperature. Project 3 will use field and laboratory experiments on sockeye salmon to test the hypothesis that how effectively an individual thermoregulates depends on its internal state (e.g. reproductive maturation, pathogen load, available somatic energy). The project will also test the hypothesis that effective thermoregulation enhances reproductive success. Project 4 will use field and laboratory experiments on bull trout and rainbow trout to investigate the relationship between water temperature and activity and test the hypothesis that the energetic costs of behavioural thermoregulation are minimized in more heterogeneous thermal habitats. These projects will improve our knowledge on and predictive capacity of the responses of freshwater fishes to temperature and will inform their management and conservation in a warming and more thermally variable world. The projects will also train a new generation of HQP (5 UG, 3 MSc, 1 PhD) and equip them with the knowledge and skills needed to further advance research and conservation of freshwater fishes in Canada.