Investigating marine carbon cycling using fatty acids and their stable carbon isotopes

使用脂肪酸及其稳定碳同位素研究海洋碳循环

• 批准号: 299311-2012
• 负责人: Budge, Suzanne
• 金额: $ 1.89万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=526119
• 关键词: Investigating; marine; carbon; cycling; using

The research interests of my group involve understanding lipid metabolism so that we can use lipids as a tool to trace carbon flow. Specifically, we are interested in the use of fatty acids (FA) in the study of carbon cycling and food web dynamics in the marine environment. FA are well suited to such studies because many dietary FA are incorporated into consumers with only minor modification to structure, making FA useful as indicators or biomarkers of their source. We propose to continue our ongoing work investigating the transfer of FA from prey to predators at low trophic levels, with the aim of developing a model to estimate predator diets. We will use two different types of information from FA data: 1) FA profiles. The proportions of FA in different species of prey are distinct and are passed to consumers with minor modification, allowing us to trace these FA signatures from prey to consumer fat stores; and 2) stable isotopes of specific FA. The distribution of carbon isotopes within specific FA of prey species are often different and are also passed to consumers with little change, allowing us to use stable isotopes of FA as an additional tracer. Both approaches, however, require investigation into the subtle biochemical changes that may occur in FA signatures or stable isotope ratios with digestion, deposition and mobilization in predator's fat stores. Thus, we propose to carry out a series of controlled feeding experiments using Atlantic pollock (Pollachius virens) as a model species to quantify any alterations in FA that may occur. With a clear understanding of biochemical changes, we can construct mathematical models to determine fish diets using FA information. These models can then be applied as part of a broader carbon-tracing technique that we are developing for application to the study of food web structure in a number of different environments. Specifically, we are interested in applying these models to ecosystems most susceptible to effects of climate changes, such as the Bering Sea and the northwest Atlantic, to detect changes in carbon cycling over time.

我的小组的研究兴趣包括了解脂质代谢，以便我们可以使用脂质作为追踪碳流的工具。具体来说，我们对脂肪酸（FA）在海洋环境中碳循环和食物网动力学研究中的应用感兴趣。 FA 非常适合此类研究，因为许多膳食 FA 只需对结构进行微小修改即可被纳入消费者体内，从而使 FA 可用作其来源的指示剂或生物标志物。我们建议继续开展研究 FA 在低营养水平下从猎物到捕食者的转移的研究，目的是开发一个模型来估计捕食者的饮食。我们将使用 FA 数据中的两种不同类型的信息：1) FA 配置文件。不同种类猎物中的 FA 比例是不同的，并经过微小修改后传递给消费者，使我们能够追踪这些 FA 特征从猎物到消费者脂肪储存的过程； 2) 特定 FA 的稳定同位素。猎物物种的特定 FA 内碳同位素的分布通常不同，并且也几乎没有变化地传递给消费者，这使得我们能够使用 FA 的稳定同位素作为额外的示踪剂。然而，这两种方法都需要研究捕食者脂肪储存中 FA 特征或稳定同位素比率在消化、沉积和动员过程中可能发生的微妙生化变化。因此，我们建议使用大西洋狭鳕（Pollachius virens）作为模型物种进行一系列受控喂养实验，以量化可能发生的 FA 的任何变化。清楚地了解生化变化后，我们可以构建数学模型，利用 FA 信息来确定鱼类的饮食。这些模型可以作为我们正在开发的更广泛的碳追踪技术的一部分，用于研究许多不同环境中的食物网结构。具体来说，我们有兴趣将这些模型应用于最容易受到气候变化影响的生态系统，例如白令海和西北大西洋，以检测碳循环随时间的变化。