International Research Fellowship Program: Disentangling the Factors Mediating Marine Trophic Cascades Over a Latitudinal Gradient in Australia

0853117 madina：该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。国际研究奖学金项目使美国科学家和工程师能够在国外进行9至24个月的研究。该计划的奖励为联合研究提供了机会，并利用独特或互补的设施、专业知识和国外的实验条件。该奖项将支持Elizabeth M. P. Madin博士与悉尼科技大学的David Booth博士和澳大利亚詹姆斯库克大学的Philip Munday博士进行为期24个月的研究。长期以来，人们一直注意到，在温带比热带海洋系统中更常观察到营养级联，即顶级捕食者的移除交替驱动低营养水平丰度的增加和减少。许多因素已经被假设影响级联的发生和大小，但只有一个子集可能在纬度梯度上变化。该项目通过解决以下问题定量地探讨了这一问题：在温带和热带海洋生态系统中，什么因素导致了营养级联发生和大小的明显差异？作为该项目的一部分，正在收集澳大利亚东海岸七个地点不同生态系统类型的大尺度梯度上的这些中介因子的第一个标准化的、可比较的数据，以确定哪些因素（如果有的话）可能对全球观测到的纬度格局负责。根据这些信息，正在开发一个介导海洋营养级联的因素预测模型，该模型应该为防止人为引起的级联提供有价值的指导。美国东海岸为探索生态系统功能的纬度梯度提供了无与伦比的机会。当地项目合作者及其实验室分别在热带和温带海洋系统生态学方面具有关键的专门知识。大卫·布斯博士？他的实验室主要关注澳大利亚东南部的温带系统，他有一个高度互动的实验室小组，研究类似的大规模生态问题。菲利普·蒙迪医生？美国的研究主要集中在鱼类与栖息地的关系、海洋营养级联中关键的生态相互作用以及气候变化对这些关系的影响。重要的是，与大多数海洋生态学家不同，两位博士。Booth和Munday对猎物行为在调解种间相互作用中的作用有经验，这是本研究的一个关键组成部分。这项研究将大大增加我们对海洋生态系统中自上而下效应的系统特征的理解。这些知识是至关重要的，因为为了了解海洋生态系统在未来可能如何变化，我们必须首先了解调节它们的因素。预计全球海产品需求将继续增加，这意味着渔业资源可能会表现出越来越不稳定的种群动态，导致营养级联的可能性增加。

0853117MadinThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Elizabeth M. P. Madin to work with Dr. David Booth at the University of Technology, Sydney and Dr. Philip Munday at James Cook University in Australia.It has long been noted that trophic cascades, where removal of top predators alternately drives increases and decreases in abundances of lower trophic levels, are more commonly observed in temperate than tropical marine systems. Many factors have been hypothesized to affect the occurrence and magnitude of cascades, but only a subset likely vary over latitudinal gradients. This project quantitatively explores this issue by addressing the question: What factors are responsible for the apparent disparity in trophic cascade occurrence and magnitude in temperate versus tropical ocean ecosystems? As part of this project the first standardized, comparable data is being collected for these mediating factors over a large-scale gradient of different ecosystem types at seven locations along the east coast of Australia to determine which, if any, may be responsible for the latitudinal patterns observed globally. From this information, a predictive model of factors mediating marine trophic cascades is being developed that should provide valuable guidance towards preventing human-induced cascades.Australia?s east coast offers an unparalleled opportunity to explore latitudinal gradients in ecosystem function. The local project collaborators and their laboratories have critical expertise in the ecology of tropical and temperate marine systems, respectively. Dr. David Booth?s lab focuses largely on the temperate systems of southeastern Australia and he has a highly interactive lab group working on similarly large-scale ecological questions. Dr. Philip Munday?s research focuses heavily on fish-habitat associations, the key ecological interaction in marine trophic cascades, and climate change effects on these associations. Importantly, unlike most marine ecologists, both Drs. Booth and Munday have experience in the role of prey behavior in mediating interspecific interactions, a key component of this study. This research will greatly increase our understanding of the system characteristics mediating top-down effects in marine ecosystems. This knowledge is critical because in order to understand how marine ecosystems are likely to change in the future we must first understand the factors that regulate them. The projected continued increase in the global demand for seafood means that fisheries stocks will likely exhibit increasingly unstable population dynamics leading to increased likelihood of trophic cascades.