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通过表达生活在特定环境中的有机体的总每日能量需求(每克动物每天所需能量的千焦耳)来建立动物能量平衡的模型和方法。这些工具可以帮助理解生态系统中的能源限制如何影响自然界的模式，包括个体动物的行为(例如，最佳觅食理论)、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，许多类型的人类介导的应激源(如有毒化学品、栖息地丧失、全球变暖、物种入侵)会引起生物能量影响，首先影响动物的代谢率，然后随着时间的推移损害动物的生长、繁殖产量和适应能力。直接测量环境中的动物代谢率可以提供生态应激源影响的早期预警，并可用作帮助评估种群和生态系统健康的指标。测量鱼的现场每日能量需求，也称为现场代谢率(FMR)的方法很少。这项提议将校准持久性有机污染物(POPs)作为鱼类田间代谢率的示踪剂，并展示这些化学示踪剂在水生生态和生态应激源感兴趣的主题中的应用。多氯联苯等遗留污染物分布在全球各地，但由于环境浓度下降，与有毒影响的联系较少。这些化学物质很有希望用作动物生物能量学的被动示踪剂。本提案中所述的方法将使用实验室研究来证明，持久性有机污染物--鱼类FMR的示踪剂方法产生与呼吸测量法等标准实验室方法类似的估计值。最后，我将进行实验室、中观和湖泊研究，以演示该方法在回答生态和生态应激源问题上的应用。一组案例研究将推断浑浊如何导致鱼类的生物能量压力。另一项研究将展示一系列湖泊中黄花鱼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.