REU: Mechanisms Controlling the Production and Fate of Insect Detritivores in the Profundal of Lakes

湖泊中产生的大部分有机物沉降到深海沉积物中，在那里它支持着一个底栖动物营养动物群落，通常以手摇蝇科的幼虫为主。这些昆虫（蠓）是浮游植物和鱼类之间重要的营养纽带。一般认为，浮游植物产量更高的湖泊，其次生产量也会更高，这是由这种腐生物群落产生的，最终是由鱼类产生的。我们不知道这些生态系统成分之间的联系有多紧密，也不了解这种耦合的可能的营养和生活史机制。这项研究提出了以下问题：深海摇尾鱼的产量是否反映了该群落的食物供应，或者种群密度是否太低而无法充分利用现有资源。试点实验将开发操纵食物供应和幼虫招募到深海底栖动物的技术，以测试有关可能限制深海昆虫生产的因素的假设。深海优势物种的二次生产模型也将量化通过捕食上升的蛹而对鱼类造成的产量损失。这项工作将阐明深层底栖动物在初级生产和鱼类之间的营养联系中的作用。

Much of the organic matter produced in lakes sinks to profundal sediments where it supports a community of benthic detritivores, often dominated by larvae of the Chironomidae. These insects (midges) are an important trophic link between phytoplankton and fish. It is generally thought that lakes more productive of phytoplankton will have higher secondary production by this detritivore community, and ultimately by fish. We do not know how closely these ecosystem components are linked, nor do we understand possible trophic and life history mechanisms for such coupling. This research asks whether production by profundal chironomids reflects the food supply to this community, or whether population densities are often too low to fully utilize available resources. Pilot experiments will develop techniques for manipulating food supply and larval recruitment to the profundal benthos to test hypotheses regarding factors that may limit profundal insect production. A model of secondary production by a dominant profundal species will also quantify the loss of production to fish through predation on ascending pupae. This work will clarify the role of the profundal benthos in the trophic linkage between primary production and fish.