Zooplankton in highly heterogenous estuarine ecosystems: ecological and evolutionary processes and interconnectivity

河口过渡区是淡水与咸水混合的地方，是全世界整个河流系统的关键生态系统。这些生态系统在生物生产力方面具有很高的生态价值，而生物生产力受河口再循环、潮汐混合和淡水排放等物理特性的强烈驱动。圣劳伦斯河口是加拿大自然遗产的一部分，是连接大陆和大西洋的重要动脉。在生态学上，圣劳伦斯河口过渡带是甲壳类动物和具有重要生态和商业价值的鱼类的重要保留区和育雏区。高能量、复杂的河口生态系统的高生产力和时空异质性使其成为研究连通性对营养关系和生物过程影响的理想场所。即使认识到种群和群落动态受营养相互作用和运输过程的调节，这些过程决定了环境空间复杂性和连通性，但这些过程在河口的整体生态系统意义仍未得到很好的理解。我的研究计划的目标是显著推进我们对浮游动物关键物种在高度可变环境中控制生态弹性的主要机制的理解。我的目标是建立环境变化如何作用于浮游动物生产和消耗的关键生物过程，这绝对会影响整个河口海景的浮游动物种群动态。我的研究项目是基于食物网海景方法。我们将获取并结合关于生态生理学、遗传多样性、滋养动力学和整个河口景观连通性的新颖和重要的科学知识，作为影响浮游动物动力学的主要驱动因素。这一知识对于补充我们对从初级生产到三级营养水平的营养转换的理解至关重要，因为浮游动物通常代表了上层营养水平（例如鱼类）的营养基础。本文将以桡足类、粘虫类和鱼类幼虫为研究对象，分析桡足类优势物种群Eurytemora affinis及其粘虫和鱼类捕食者的时空生产模式、可塑性、遗传多样性和营养耦合之间的关系。这一研究项目将极大地促进我们对浮游动物生产力模式的科学理解，因为这一知识对海洋资源的保护和可持续利用以及基于生态系统的管理方法中的生态系统健康至关重要。

Estuarine transition zones, where freshwater mixes with saltwater, are critical ecosystems for entire river systems worldwide. These ecosystems have a high ecological value in terms of biological productivity which is strongly driven by physical properties such as estuarine re-circulation, tidal mixing and freshwater discharge. The St. Lawrence Estuary, part of Canada's natural heritage, is the important artery between the continent and the Atlantic Ocean. Ecologically, the St. Lawrence estuarine transition zone represents important retention and nursery zones for crustaceans and ecologically and commercially important fishes. The high productivity and spatiotemporal heterogeneity of this highly energetic and complex estuarine ecosystem makes it an ideal site to study the influence of connectivity on trophic relationships and biological processes. Even if it is recognized that population and community dynamics are regulated by trophic interactions and transport processes that determine environmental spatial complexity and connectivity, the overall ecosystem significance of these processes in estuaries is not well understood. The goal of my research program is to significantly advance our understanding of the main mechanisms controlling the ecological resilience of zooplankton key species in a highly variable environment. I aim to establish how environmental variability acts on key biological processes involved in production and consumption of zooplankton, that most definitely impact zooplankton population dynamics throughout the estuarine seascape. My research program is based on a food-web seascape approach. We will acquire and combine novel and crucial scientific knowledge on eco-physiology, genetic diversity, trophodynamics and connectivity throughout the estuarine seascape as primary drivers influencing zooplankton dynamics. This knowledge is essential to complement our understanding of the trophic turnover from primary production to tertiary trophic levels, as zooplankton often represents the nutritional basis for upper trophic levels (e.g. fish). We will focus on the most important estuarine species, such as copepods, mysids and fish larvae to disentangle the relationships between spatio-temporal production patterns, plasticity, genetic diversity and trophic coupling of the dominant copepod species complex Eurytemora affinis and its mysid and fish (smelt, striped bass) predators. This research program will significantly advance our scientific comprehension of zooplankton productivity patterns, as this knowledge is of crucial relevance to the conservation and sustainable utilization of marine resources and ecosystem health in an ecosystem-based management approach.