Collaborative Research: Shifting hotspots - How do consumer aggregations interact to influence resource heterogeneity and fluxes in streams?

该项目将确定短寿鱼类和长寿贻贝群落在何时何地重叠（生物热点），以及这种重叠如何影响两条河流中营养物质的数量和传播。营养物喂养水生植物，支持河流食物网，并且假设动物聚集可以影响营养物污染。了解这些类型的生物热点如何相互作用将进一步加深我们对河流功能的认识，并为河流恢复提供目标。为了了解河流中鱼类和贻贝热点的生态，研究人员将采用包括实地监测、实验和数学建模在内的互补方法。此外，pi将培训一名博士后研究员、本科生和研究生，并为K-12教师组织外联讲习班，开发与水质和生态系统服务相关的项目。发生在动物聚集区（生物地球化学热点）的生态过程对生态系统健康很重要，可以帮助减轻营养物污染。动物聚集形成斑块，其中能量转移和养分循环等过程高于斑块外。长寿命的淡水贻贝生活在局部斑块的沉积物中，这些斑块是稳定的、长期的生物地球化学热点。相反，在寿命较短的地方，鱼类的出现取决于河流的流量状况。鱼类聚集是移动的、广泛的、短期的生物地球化学热点。该项目量化了河流中贻贝和鱼类聚集的时空重叠和相互作用。实地研究将量化两条河流在不同流量条件下的鱼类和贻贝丰度，以确定斑块的大小和位置。相关的实地研究将量化贻贝和鱼类在低流量和高流量条件下的生态服务。中生态实验将使用化学技术来追踪鱼类和贻贝聚集物中的营养物质在食物网中其余部分的运动。最后，将利用生态系统动力学的计算机模型，从小规模实地研究中产生的鱼类和贻贝分布和流量数据扩大到整个河流的规模。一个讲习班将培训教师进行可在课堂上使用的水质活动。

This project will determine where and when short-lived fish and long-lived mussel communities overlap (biological hotspot) and how this overlap affects the amount and spread of nutrients in two rivers. Nutrients feed aquatic plants that support riverine food webs, and it is hypothesized that animal aggregations can influence nutrient pollution. Understanding how these types of biological hotspots interact will further our knowledge of river function and provide targets for river restoration. To understand the ecology of fish and mussel hotspots in rivers, the investigators will use complementary approaches including field monitoring, experiments, and mathematical modeling. In addition, the PIs will train a post-doctoral researcher and undergraduate and graduate students as well as organize outreach workshops for K-12 teachers to develop programs associated with water quality and ecosystem services.The ecological processes that occur at animal aggregations (biogeochemical hotspots) are important for ecosystem health and can help mitigate nutrient pollution. Animal aggregations create patches where processes such as energy transfer and nutrient recycling are higher than outside of patches. Long-lived freshwater mussels live buried in the sediment in localized patches that serve as stable, long-term biogeochemical hotspots. In contrast, where shorter-lived, fish occur depends on flow conditions in rivers. Fish aggregations serve as mobile, widespread, short-term biogeochemical hotspots. This project quantifies the spatial and temporal overlap and interactions between mussel and fish aggregations in rivers. A field study will quantify fish and mussel abundance under different flow conditions in two rivers to determine patch size and location. A correlative field study will quantify ecological services performed by mussel and fish aggregations under low and higher flow conditions. Mesocosm experiments will use chemical techniques to track the movement of nutrients from fish and mussel aggregates through the rest of the food web. Lastly, computer models of ecosystem dynamics will be used to scale from fish and mussel distribution and flow data generated in the small-scale field study up to the whole river scale. A workshop will train teachers in water quality activities they can use in their classrooms.