Trophic transfer of fatty acids in marine food webs

海洋食物网中脂肪酸的营养转移

• 批准号: RGPIN-2017-04296
• 负责人: Budge, Suzanne
• 金额: $ 2.91万
• 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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=688136
• 关键词: Trophic; transfer; fatty; acids; marine

The research interests of my group are focused on the use of lipids and fatty acids (FA) as tools to study carbon flow 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 modifications to structure, making FA useful as indicators or biomarkers of their source. Here, we propose to continue our ongoing work investigating the transfer of FA from prey to predators at low trophic levels by examining trophic transfer efficiencies of FA. This is a measure of the amount of FA deposited in a predator's tissue relative to the amount available in its diet, and we believe these will vary with consumer, concentration of FA and FA structure. Several FA, such as long chain omega-3 FA, are essential nutrients, required for growth and survival by all organisms. In the marine food web, the majority of these essential FA are synthesized only by phytoplankton; thus, it is particularly important to understand the efficiency with which such nutrients are transferred from diet to consumer. Trophic transfer efficiencies can also be incorporated into methods we are developing to estimate consumer diets by comparison of FA patterns, or profiles, in predator and prey. They are important in that application because they allow us to compensate for changes made to the diet FA profile by catabolism and other processes in the predator. ******We are proposing three specific objectives: 1) examine the influence of FA structure, dietary concentration, tissue and species on transfer efficiency of FA, using calanoid copepods (Calanus finmarchicus), Atlantic pollock (Pollachius virens) and Atlantic salmon (Salmo salar) as model species; 2) test the influence of trophic transfer efficiencies in our statistical models on the accuracy of diet estimates by conducting feeding studies with Atlantic salmon fed different diet mixtures; and 3) incorporate trophic transfer efficiencies of FA into our statistical models and apply to existing datasets from Baffin Island and the Bering Sea to estimate diets of Atlantic and Arctic cod (Gadus morhua and Boreogadus saida). These are ecosystems that are most susceptible to the effects of climate change and make good candidates to detect variation in carbon cycling over time. At larger scope, we will use trophic transfer efficiencies, combined with production levels of FA derived from remote sensing of phytoplankton, to estimate the essential FA budget of the ocean. Fundamentally, we believe that incorporation of these essential nutrients into mechanistic models will improve the accuracy of predictions of ecosystem properties and shifts, ultimately leading to better decision-making regarding management and conservation of our marine resources. Measurement of trophic transfer efficiencies of essential FA, as we have proposed here, is a necessary first step for their inclusion in such models.

我的小组的研究兴趣集中在使用脂质和脂肪酸（FA）作为工具来研究海洋环境中的碳流和食物网动态。FA非常适合此类研究，因为许多膳食FA仅对结构进行微小修改就被纳入消费者体内，使得FA可用作其来源的指示剂或生物标志物。在这里，我们建议继续我们正在进行的工作，调查FA从猎物到捕食者在低营养水平的营养转移效率的FA。这是一个衡量沉积在捕食者的组织中的FA的量相对于其饮食中的可用量，我们相信这些将随着消费者，FA的浓度和FA结构而变化。几种FA，如长链omega-3 FA，是所有生物体生长和生存所需的必需营养素。在海洋食物网中，这些必需FA中的大多数仅由浮游植物合成;因此，了解这些营养物质从饮食转移到消费者的效率尤为重要。营养转移效率也可以纳入我们正在开发的方法来估计消费者的饮食比较FA模式，或配置文件，在捕食者和猎物。它们在该应用中很重要，因为它们使我们能够补偿由捕食者的catabolism和其他过程对饮食FA配置文件所做的改变。** 我们提出了三个具体目标：1）研究FA结构，饲料浓度，组织和物种对FA转移效率的影响，使用哲水蚤桡足类（Calanus finmarchicus），大西洋狭鳕（Pollachius virens）和大西洋鲑鱼（萨尔莫salar）为模式种; 2）通过对喂食不同饲料混合物的大西洋鲑鱼进行饲养研究，测试我们的统计模型中营养转移效率对饲料估计准确性的影响;将FA的营养转移效率纳入我们的统计模型中，并应用于巴芬岛和白令海的现有数据集，以估计大西洋和北极鳕鱼（Gadus morhua和Boreogadus色达）的饮食。这些生态系统最容易受到气候变化的影响，是检测碳循环随时间变化的良好候选者。在更大的范围内，我们将使用营养转移效率，结合生产水平的FA来自遥感浮游植物，估计必要的FA预算的海洋。从根本上说，我们认为，将这些基本营养素纳入机械模型将提高预测生态系统特性和变化的准确性，最终导致更好的管理和保护我们的海洋资源的决策。测量营养转移效率的必要FA，因为我们已经提出了在这里，是必要的第一步，他们列入这样的模型。