Nonconsumptive predator effects in a pelagic community: an integrated laboratory, field and modeling approach

这项研究将解决一个关于物种相互作用如何影响群落的基本问题。经典的方法，包括绝大多数的实验和模型研究，关注物种如何通过捕食者-猎物的相互作用影响其他物种的密度。这种方法忽略了越来越多的研究，这些研究记录了猎物如何改变它们的表型（特征）来应对捕食者，以减少被捕食的风险，以及这反过来如何深刻地影响物种相互作用的后果。有大量证据表明，捕食者的这种非消耗效应（NCEs，也包括性状介导或非致死效应）在远洋五大湖和海洋生态系统中可能很重要。然而，潜在的机制是众所周知的，对nce的影响知之甚少，而且几乎没有在大型远洋生态系统中进行nce的研究。nce的存在会强烈影响物种相互作用的定性和定量性质以及群落的性质。这个项目将审查海洋和大湖系统中国家海洋生态系统的作用和运作。研究人员将检查由一种无脊椎捕食者——侵入性刺水蚤——引起的nce。该项目将试图回答一些广泛的问题：食蚜虫对猎物的影响如何影响它们对五大湖社区的净影响？nce在复杂的领域环境中有影响力吗？无脊椎捕食者的nce对浮游动物猎物组合或幼龄竞争鱼的影响是什么？诸如资源水平、温度和光线等因素如何影响捕食者的影响？NCE对猎物组合的影响（通过对竞争的影响）？将采用基于三个目标的综合方法，将实验室研究、实地调查和建模结合起来。研究人员将：(1)确定主要浮游动物物种对虫的表型反应。这将涉及实验室研究，检查行为，形态和生活史反应。实验室研究也将量化食虫率。优化建模将指导和允许这些实验室研究的解释。(2)建立水蚤NCEs对浮游动物猎物生长速度和竞争结果的预测模型，并通过微观和中观实验对预测结果进行验证。这是一个关键的方法论组成部分：如果模型准确地预测了诱导性状变化，以及它们在中观实验中对物种相互作用的影响，这就增加了在自然系统中形成预测模型的能力。(3)利用基于上述实践和实地调查得出的参数的生态模型，确定野外白蚁的nce。实地调查将检查在实地浮游动物猎物的影响，并分类丰度和参数，如幼鱼的密度和位置和非生物因素。这项研究将通过解决五大湖和海洋系统中物种相互作用的一个关键但鲜为人知的组成部分，从而产生重大的智力贡献。社会对入侵物种的关注和兴趣，包括对五大湖食物网的影响，将促进教育推广。此外，将从该项目发展同各机构（例如，NOAA大湖环境研究实验室）的密切联系，并将有强有力的外联组成部分促进教育机会。例如，许多来自高中和管理机构的个人和团体来GLERL接受教育和培训。此外，五大湖海洋资助网络的扩展教育工作者已同意通过帮助pi与海洋科学和教育卓越五大湖（COSEE）五大湖和海洋资助中心合作，与教育工作者建立研究桥梁。该项目的研究人员将与专业的教育外展伙伴合作，以增强研究的广泛影响。COSEE Great Lakes已经有了一个覆盖整个地区教师的框架，其中包括强调包括部落教育工作者在内的代表性不足的群体，COSEE和Sea Grant也在制定各种课程。这个项目将有助于这些努力。最后，研究生和本科生在研究和推广方面的培训是这项活动的一部分。

This study will address a fundamental issue about how species interactions influence communities. Classical approaches, including the vast majority of experimental and modeling studies, focus on how species affect the density of other species through predator-prey interactions. This approach ignores a growing body of work that documents how prey modify their phenotype (traits) in response to predators to reduce predation risk, and how this, in turn, can profoundly influence the consequences of species interactions. There is abundant evidence that such nonconsumptive effects (NCEs, also trait-mediated or nonlethal) of predators could be important in pelagic Great Lakes and marine ecosystems. Whereas, the underlying mechanism is well known, there is little understanding of the influence of NCEs, and almost no studies of NCEs in large pelagic ecosystems. The existence of NCEs could strongly affect the qualitative and quantitative nature of species interactions and the properties of communities. This project will examine the role and operation of NCEs in marine and Great Lake systems. The investigators will examine NCEs caused by an invertebrate predator, the invasive spiny water flea Bythotrephes. The project will attempt to answer the broad questions: How do Bythotrephes induced effects on prey influence their net effect on Great Lakes communities? Are NCEs influential in complex field settings? What is the influence of NCEs of an invertebrate predator on the zooplankton prey assemblages or on the young-of-year fish competitors? How do factors such as resource level, temperature, and light affect the influence of a predator?s NCE on a prey assemblage (via effects on competition)? A comprehensive approach based on three objectives will be used that integrates laboratory studies, field surveys and modeling. The investigators will: (1) Determine the phenotypic responses of key zooplankton species to Bythothrephes. This will involve laboratory studies that examine behavioral, morphological and life history responses. Laboratory studies will also quantify Bythotrephes predation rates. Optimization modeling will guide and allow interpretation of these laboratory studies. (2) Develop predictive models of the NCEs of Bythothrephes on zooplankton prey growth rate and competitive outcomes and test predictions with microcosm and mesocosm experiments. This is a key methodological component: If models accurately predict induced trait changes, and their consequences to species interactions in mesocosm experiments, this increases the ability to form predictive models in natural systems. (3) Determine NCEs of Bythotrephese in the field using ecological models based on parameters derived from the aforementioned exercises and field surveys. Field surveys will examine the effect of Bythotrephes on zooplankton prey in the field, and classify abundances and parameters such as young of the year fish density and position and abiotic factors. Significant intellectual contributions will result from this study by addressing a key, but poorly understood, component of species interactions in Great Lakes and marine systems. Societal concern and interest over the influence of invasive species including Bythotrephes in Great Lakes food webs will facilitate educational outreach. In addition, close associations with institutions (e.g., the NOAA Great Lakes Environmental Research Laboratory, GLERL) will develop from the project and there will be strong outreach components that foster educational opportunities. For example, many individuals and groups from high schools and management agencies come to GLERL for education and training. Further, a Great Lakes Sea Grant Network extension educator has agreed to work to bridge the research with educators by helping the PIs engage with the Center for Ocean Sciences and Education Excellence Great Lakes (COSEE) Great Lakes and Sea Grant. The investigators on this project will work with professional educational outreach partners to enhance the broader impacts from the research. COSEE Great Lakes already has a framework in place to reach teachers throughout the region and includes an emphasis on underrepresented groups including tribal educators and COSEE and Sea Grant also are working on a variety of curriculum pieces. This project will contribute to these efforts. Finally, graduate and undergraduate training in research and outreach is part of this activity.