Biochemical tracers in freshwater ecosystems

脂质，包括脂肪酸，是压力的敏感指标，以可预测的方式对环境的变化作出反应。有些脂肪酸对包括人类在内的所有动物维持最佳生理机能至关重要。这些脂肪酸称为必需脂肪酸（EFAs）。在哺乳动物中，已知EFAs在维持心血管和神经健康方面具有重要作用。在无脊椎动物和鱼类中，它们可以促进正常的发育、生长和繁殖。EFAs主要产生于水生生态系统，并通过各种机制（捕食、昆虫出现、岸漂等）从水生生态系统转移到陆地生态系统。因此，了解水生生态系统内部以及水生生态系统与邻近陆地生态系统之间对其生产和分布的全球威胁至关重要。有可能影响食物链底层（即藻类）EFAs生产的三种大规模压力源。这些包括;气候变化、外来入侵者和富营养化。脂肪酸的另一个特点是它们作为生物标记物的能力（通过食草或捕食过程从一个生物体传递到另一个生物体的化合物不变）。这个项目的目标是；a)在实验室中详细检查气候变化（温度升高）对藻类中EFAs产生的影响，包括它们向浮游动物（食草动物）的转移；b)精炼和开发新的生化示踪剂，使研究人员能够在整个水生食物网中追踪与外来入侵者（斑马贻贝）相关的碳流，从而更深入地了解外来入侵者的全面影响；c)展示EFAs如何，在藻类中产生，随着时间的推移，随着老鼠年龄的增长，它们会保留在大脑的特定区域。更彻底地了解全球对全民教育生产的威胁，以及这可能如何影响它们向陆地生物的转移，将为我们保护独特和宝贵的淡水生态系统提供新的有力动力。

Lipids, including fatty acids, are sensitive indicators of stress that respond, in predictable ways, to changes in the environment. Some fatty acids are critical to the maintenance of optimal physiological performance in all animals including humans. Those fatty acids are called essential fatty acids (EFAs). In mammals EFAs are known to be important in the maintenance of cardiovascular and neural health. In invertebrates and fish they are known to promote normal development, growth and reproduction. EFAs are primarily produced in aquatic ecosystems and from there are transferred to terrestrial ecosystems via a variety of mechanisms (predation, insect emergence, shore drift etc). Therefore it is critically important to understand global threats to their production and distribution within aquatic ecosystems and between aquatic ecosystems and neighboring terrestrial ecosystems. Three large-scale stressors that have the potential to impact the production of EFAs at the base of the food chain (i.e. in algae). These include; climate change, exotic invaders and eutrophication. Another special feature of fatty acids is their ability to act as biomarkers (compounds that are passed, unchanged, from one organism to another through the processes of herbivory or predation). This project is targetted towards; a) a detailed examination, in the laboratory, of the effects of climate change (temperature increases) on the production of EFAs in algae including their transfer to zooplankton (herbivores), b) refining and developing new biochemical tracers that will allow researchers to track the flow of carbon associated with exotic invaders (zebra mussels) throughout the aquatic food web and thus gain a deeper understanding of the full scale of exotic invader impacts, and, c) showcase how EFAs, produced in algae, are retained, through time, in selected regions in the the brains of mice as they age. A more thorough understanding of the global threats to EFA production and how this may affect their transfer to terrestrial organisms will provide us with a new and powerful incentive to conserve our unique and precious freshwater ecosystems.