US-Sweden Cooperative Research: Complex Interaction Among Fish Predators in Littoral Benthic Communities

该奖项将支持俄亥俄州立大学的Roy Stein博士和瑞典隆德大学的Christer Bronmark博士在水生生态系统方面的合作研究。拟议项目的目标是检查和评估捕食性鱼类之间的相互作用，这些相互作用从结构上影响天然池塘的复杂环境。斯坦博士目前正在威斯康星州北部的湖泊进行一项大规模实验，以研究捕食者在构建近岸群落中的作用。威斯康星州的研究小组通过实验室实验、湖泊调查和大规模近岸中游实验(近岸的部分区域被窗帘围住)，正在探索生物和非生物因素如何影响滨海群落的方方面面，包括捕食性鱼类、小龙虾、蜗牛、附生植物和大型植物。由于瑞典隆德附近有大量的小池塘，池塘里有食鱼和底栖鱼类、蜗牛、附生植物和大型植物，因此可以在不使用大型围栏的情况下对捕食者进行整个系统的操纵。与威斯康星州的工作相反，为瑞典提出的工作，包括池塘调查(以确定田野模式)和捕食者的操纵(其中北部的梭鱼和沟渠密度是处理变量)，将以更广泛的方式评估鱼类捕食者如何相互作用，直接和间接影响蜗牛、附生植物、以及天然池塘中的大型植物。这项工作将直接测试营养级联假说，该假说最近应用于湖泊的Pelagia，但在底栖生物和滨海群落的结构复杂环境中基本上没有得到检验。该项目将受益于两名调查员的互补专业知识。Bronmark博士在蜗牛、附生植物和大型植物之间的相互作用方面拥有丰富的经验。斯坦博士的专长在于量化捕食者和猎物之间的行为互动，以及这些互动可能如何受到栖息地结构的影响。

This award will support collaborative research in aquatic ecosystems between Dr. Roy Stein, Ohio State University and Dr. Christer Bronmark, University of Lund, Sweden. The objective of the proposed project is an examination and evaluation of interactions among fish predators which affect the >structurally.complex environment of natural ponds. Dr. Stein is currently carrying out a large scale experiment in the northern Wisconsin lakes to study the role of predators in structuring nearshore communities. Using laboratory experiments, lake surveys and a large.scale inshore mesocosm experiment (where portions of the nearshore are enclosed by a curtain), the Wisconsin research team is exploring how biotic and abiotic factors influence all facets of the littoral community, including predatory fishes, crayfish, snails, periphyton and macrophytes. Because of the abundance of small ponds near Lund, Sweden with piscivorous and benthivorous fishes, snails, periphyton and macrophytes, whole.system manipulations of predators can be done without resorting to the use of large enclosures. In contrast to the Wisconsin work, the work proposed for Sweden, which includes a pond survey (to qualify field patterns) and predator manipulations (where northern pike and tench densities are treatment variables), will evaluate in a more extensive fashion how fish predators interact to directly and indirectly influence snails, periphyton, and macrophytes in natural ponds. This work will directly test the trophic cascade hypothesis, recently applied to the pelagia of lakes, but largely untested in the structurally.complex environment of the benthic, littoral community. The project will benefit from the complementary expertise of the two investigators. Dr. Bronmark has extensive experience with interactions among snails, periphyton and macrophytes. Dr. Stein's expertise lies in quantifying the behavioral interactions between fish predators and their prey and how these interactions might be mediated by habitat structure.