Collaborative Research: Decomposing the effects of diversity on the abundance of marine parasites

随着地球生态系统经历生物多样性的快速变化，疾病生态学家转向一个紧迫的问题：生物多样性的减少可能如何影响寄生虫的传播？换句话说，生物多样性的丧失是否会侵蚀传播过程中的自然制衡，从而增加寄生虫的丰度？或者，它是否通过消除寄生虫所依赖的自由生活的生物多样性来减少寄生虫的丰度？这项研究将通过评估18个可复制的珊瑚礁生态系统中鱼类生物多样性和寄生虫丰度之间的关系，构成对任何生态系统中这些问题的第一次全面测试。该项目不仅将探索鱼类生物多样性的减少是否与寄生虫负担的增加或减少有关，还将评估寄生虫和宿主的特征或地理距离是否影响这种关系的方向和强度。在迅速发展的疾病生态学领域，将要测试的理论是最重要和最有争议的理论之一，这项工作代表了一种新的、创造性的方法来解决一个长期存在但尚未解决的研究问题。该项目将对不断变化的世界中寄生虫传播的性质产生变革性的见解。此外，它将通过在加利福尼亚州蒙特利湾启动分子生态学研究实习，将一群代表性不足的本科生置于中心研究角色，并通过与美国自然历史博物馆保护教育者和从业者网络合作，开发和传播关于寄生虫生物多样性的优质教育工具，将教育与研究紧密结合在一起。寄生虫往往是隐藏的，很容易被忽视，但它们在生态上很重要，影响着每一种海洋动物。疾病生态学领域在生物多样性丧失是否会加剧寄生虫传播的问题上存在不确定性和分歧，因为它缺乏制定令人信服的实证测试所需的全面、多宿主、多寄生虫、广泛空间尺度的数据集。为了回答这个顽固的问题，PI将通过利用海洋模型系统的优势来生成一个具有前所未有的复制、分类和空间分辨率的数据集。该项目的核心是一项自然实验，在该实验中，将对超过77种寄生虫物种和18个复制的珊瑚礁生态系统的寄生虫丰度进行量化，以获得高度分辨的宿主生物多样性梯度。由此产生的数据集将对生物多样性-寄生虫丰度关系的假设进行批判性测试，揭示这种关系的方向、形状和规模依赖关系如何在一系列不同的寄生虫分类群中变化，并解决疾病生态学文献中感兴趣的问题？对海洋保护至关重要。该项目将解决以下问题：(Q1)对于检测到的每一种寄生虫，生物多样性和寄生虫丰度之间的关系的方向和形式是什么？(Q2)哪些因素(如传播策略和宿主专一性等寄生虫特征、人体大小等宿主特征)决定了生物多样性和寄生虫丰度之间关系的方向和形式？(Q3)空间尺度如何与寄生虫传播能力相互作用，以缓和生物多样性对寄生虫丰度的影响？为解决这些问题，该项目将把来自六个赤道太平洋岛屿(北线群岛)的关于鱼类生物多样性和珊瑚礁鱼类寄生虫丰度的现有数据集与来自另外12个岛屿(南线群岛和法属波利尼西亚)的新样本合并。由此产生的数据集将反映横跨18个岛屿的7种珊瑚礁鱼类的77个后生动物寄生虫分类群的负担。这项工作将提供世界上第一个关于各种寄生虫类群、寄主类群和空间尺度上的生物多样性与疾病关系的方向、大小和形状的数据，并将全面确定在哪些条件下生物多样性可能对确定寄生虫的丰度具有重要作用？对生态学和生物海洋学的根本性贡献。该项目还将把教育和研究紧密结合起来，让一群代表性不足的少数族裔本科生担任中心研究角色：执行估计寄生虫传播距离所需的分子分析。分子生态学的暑期研究实习将在加州州立大学蒙特利湾分校设立，这是一家为拉美裔服务的机构。该项目还将资助开发一个关于寄生虫生物多样性的同行评议学习模块，该模块将与美国自然历史博物馆合作开发和传播，并将支持两名研究生、一名博士后学者和几名本科生的培训。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

As Earth's ecosystems experience rapid biodiversity change, disease ecologists have turned to an urgent question: how might reductions in biodiversity affect the transmission of parasites? In other words, does biodiversity loss increase the abundance of parasites by eroding natural checks and balances on transmission? Alternatively, does it decrease parasite abundance by removing the free-living biodiversity on which parasites depend? This study will constitute the first comprehensive test of these questions in any ecosystem by evaluating the relationship between fish biodiversity and parasite abundance across 18 replicate coral reef ecosystems. Not only will the project explore whether reductions in fish biodiversity are associated with increases or decreases in parasite burdens, it will also assess whether parasite and host traits or geographical distance influence the direction and strength of this relationship. The theories to be tested are among the most important and controversial in the rapidly growing field of disease ecology and this work represents a novel, creative approach to a long standing, but unresolved research question. The project will yield transformative insights into the nature of parasite transmission in a changing world. Furthermore, it will intimately intermingle education with research by launching the Research Internship in Molecular Ecology at California State Monterey Bay, which will place a group of underrepresented undergraduates in a central research role, and by developing and disseminating quality educational tools for teaching about parasite biodiversity through collaboration with the Network of Conservation Educators and Practitioners at the American Museum of Natural History. Parasites are often hidden and can be easy to overlook, but they are ecologically important and affect every population of marine animals. The field of disease ecology is plagued by uncertainty and disagreement over whether biodiversity loss exacerbates parasite transmission, because it lacks the comprehensive, multi-host, multi-parasite, broad-spatial-scale dataset needed to formulate a convincing empirical test.To answer this recalcitrant question, the PIs will generate a dataset of unprecedented replication and taxonomic and spatial resolution, by exploiting the advantages of a marine model system. The project is centered on a natural experiment in which the abundance of parasites will be quantified across a highly resolved gradient of host biodiversity, for more than 77 parasite species and 18 replicate coral reef ecosystems. The resulting dataset will critically test hypotheses for the biodiversity?parasite abundance relationship, revealing how the direction, shape, and scale-dependence of this relationship vary across a diverse array of parasite taxa, and resolving questions of burning interest in the disease ecology literature ? and of vital importance to marine conservation. This project will address the following questions: (Q1) For each parasite species detected, what is the direction and shape of the relationship between biodiversity and parasite abundance? (Q2) What factors (e.g., parasite traits like transmission strategy and host specificity, host traits like body size) determine the direction and shape of the relationship between biodiversity and parasite abundance? (Q3) How does spatial scale interact with parasite dispersal capacity to moderate the effects of biodiversity on parasite abundance? To address these questions, the project will integrate an existing dataset on fish biodiversity and abundance of coral reef fish parasites from six equatorial Pacific islands (the Northern Line Islands) with new sampling from 12 additional islands (the Southern Line Islands and French Polynesia). The resulting dataset will reflect the burden of 77 metazoan parasite taxa for seven species of coral reef fishes across18 islands. This work will provide the world's first data on the direction, magnitude, and shape of the biodiversity?disease relationship across a diversity of parasite taxa, host taxa, and spatial scales, and will comprehensively identify conditions under which biodiversity is likely to be important in determining the abundance of parasites ? a fundamental contribution to ecology and to biological oceanography. The project will also intimately integrate education with research by placing a group of underrepresented minority undergraduates in a central research role: performing the molecular analyses required to estimate parasite dispersal distance. A summer Research Internship in Molecular Ecology will be established at California State University Monterey Bay, a Hispanic-Serving Institution. The project will also underwrite the development of a peer-reviewed learning module on parasite biodiversity, to be developed and disseminated in collaboration with the American Museum of Natural History, and will support the training of two graduate students, one postdoctoral scholar, and several undergraduates.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.