Use of globally dispersed chemical tracers to measure in situ bioenergetic stress in fish and aquatic organisms

生物能量学领域提供了模型和方法，通过表达在给定环境中生活的生物体每天的总能量需求（每克动物每天所需的能量千焦）来建立动物的能量平衡。这些工具可以帮助理解生态系统中的能量限制如何影响自然模式，包括单个动物的行为（例如最优觅食理论）、动物种群的生长和健康，以及用于评估物种之间相互作用的相对强度。此外，许多人类介导的应激源（如有毒化学品、栖息地丧失、全球变暖、物种入侵）会引起生物能影响，首先影响动物的代谢率，随着时间的推移，会损害动物的生长、繁殖产出和健康。直接测量动物在环境中的代谢率可提供生态应激源效应的早期预警，并可作为帮助评估种群和生态系统健康的指标。很少有可用的方法来测量鱼类的原位每日能量需求，也称为现场代谢率（FMR）。本提案将校准持久性有机污染物（POPs）作为鱼类现场代谢率的示踪剂，并展示这些化学示踪剂在水生生态学和生态压力源感兴趣的主题中的应用。多氯联苯等遗留污染物在全球分布，但由于环境浓度降低，与毒性作用的联系较少。这些化学物质作为动物生物能量学的被动示踪剂具有很大的应用前景。本提案中描述的方法将使用实验室研究来证明鱼类FMR的持久性有机污染物示踪剂方法与呼吸测量等标准实验室方法产生相似的估计。最后，我将进行实验室、生态系统和湖泊研究，以证明该方法在回答生态和生态压力源问题方面的应用。一组案例研究将推断浊度如何引起鱼类的生物能量压力。另一个将展示一系列湖泊中黄鲈种群在冰下的实际能量需求。

The field of bioenergetics provides models and methods to establish the energy balance of animals by expressing the total daily energy needs (kJ of energy required per gram animal per day) of an organism living in a given environment. These tools can help understand how energy limitations in ecosystems contribute to patterns in nature including the behavior of individual animals (e.g. optimal foraging theory), growth and health of animal populations as well be used to evaluate the relative strength of interactions between species. In addition, many types of human mediated stressors (e.g. toxic chemicals, habitat loss, global warming, species invasions) cause bioenergetic impacts that first affect animal metabolic rate and over time compromise growth, reproductive output and fitness of animals. Measuring animal metabolic rates in the environment directly provides an early warning of ecological stressor effects and can be used as a metric to help assess population and ecosystem health. There are few methods available for measuring the in situ daily energy requirement, also known as field metabolic rate (FMR), of fish. This proposal will calibrate persistent organic pollutants (POPs) as tracers of field metabolic rates of fish and demonstrate the application of these chemical tracers to topics of interest to aquatic ecology and ecological stressors. Legacy pollutants such as PCBs are globally distributed, but as a consequence of decreases in environmental concentrations, are less often associated with toxic effects. These chemicals have strong promise for use as passive tracers of animal bioenergetics. The described methods in this proposal will use laboratory studies to demonstrate that POPs-tracer approaches of fish FMR yield similar estimates as standard laboratory methods such as respirometry. Finally, I will perform laboratory, mesocosm and lake studies to demonstrate the application of the method to answer ecological and ecological-stressor questions. One set of case studies will deduce how turbidity causes bioenergetic stress in fish. Another will demonstrate the actual under-the-ice energy requirements of yellow perch populations in a series of lakes.