Chemical tracers of bioenergetics and energy acquisition in aquatic ectotherms

所有动物都必须通过摄食活动获取能量，但从环境中获取食物资源的方式不同，这取决于1)物种；2)生活在不同环境中的种群之间的摄食生态差异；3)特定环境中摄食行为的个体差异。生物能量学和生物能量模型提供了一种方法来建立动物的能量平衡（每天消耗的千焦耳食物相对于每日总能量需求或野外代谢率），当与生物量/产量估算相结合时，可以评估特定种群对其环境的营养影响或生态足迹。这种类型的信息需要验证食物网结构的理论模型，并测试物种多样性和生态系统稳定性之间的关系。开发测量自然环境中动物生物能量的方法也可以应用于确定鱼类放养计划、入侵物种或生态系统中主要猎物的波动的含义。描述生物能量参数（如生长和食物消耗）也可以评估人口的相对健康状况。许多压力源（如有毒化学品、营养物质富集、栖息地丧失和全球变暖）表现为生物能量效应，可以提供压力源对种群影响的早期预警。本提案将评估持久性有机污染物（POPs）在自由生活的水生两栖动物和鱼类中作为能量获取和摄食率示踪剂的使用。长期禁用的多氯联苯等遗留污染物分布在全球，由于环境浓度降低，毒性降低，并提供了良好的生态结构和生物能量学示踪剂。所描述的方法将利用实验室研究、池塘研究（中生态系统）和天然湖泊以及若干指示物种，包括豹蛙、绿蛙、牛蛙、太阳鱼和虹鳟鱼，建立持久性有机污染物作为生物能示踪剂的方法，并评估该技术在生态系统管理和生态系统健康评估实践中的潜在应用。

All animals must acquire energy through their feeding activities but obtain food resources from their environment in different ways depending on 1) the species 2) feeding ecology differences among populations living in different environments and 3) individual variation in feeding behavior within a given environment. Bioenergetics and bioenergetic models provide a method to establish the energy balance (kilojoules of food consumed per day relative to total daily energy needs or field metabolic rate) in animals and when coupled with biomass/production estimates allow an assessment of the trophic impacts, or the ecological footprint, of a given population on its environment. This type of information is needed to validate theoretical models of food web structure and to test the relationship between species diversity and ecosystem stability. Developing methods to measure animal bioenergetics in natural environments also has applications to establish the implications of fish stocking programs, invading species or fluctuations in key prey items in an ecosystem. Characterizing bioenergetics parameters (e.g. growth and food consumption) also allows assessment of the relative health of a population. Many stressors (e.g. toxic chemicals, nutrient enrichment, habitat loss and global warming) manifest themselves as bioenergetic effects and can provide an early warning of impacts of stressors on the population. This proposal will evaluate the use of persistent organic pollutants (POPs) as tracers of energy acquisition and feeding rates in free living aquatic amphibians and fish. Legacy pollutants such as the long-banned PCBs are globally distributed, exhibit reduced toxicity on account of decreases in environmental concentrations, and provide good tracers of ecological structure and bioenergetics. The described methods will use laboratory studies, pond-studies (mesocosms) and natural lakes and several indicator species including: leopard frogs, green frogs, bullfrogs, sunfish and rainbow trout to establish the method of POPs as bioenergetic tracers and evaluate the potential application of this technique to ecosystem management and ecosystem health assessment practices.