LTREB: Climatic and Density-dependent Effects on the Ecology of Sockeye Salmon and their Freshwater Ecosystems

0128902 Quinn尽管气候对生态动力学的影响得到了普遍的认可，但大多数生物学研究都过于简短，无法测试气候和生物过程之间的相互作用。或者，许多长期研究没有跨越足够的生物组织水平，以提供有意义的洞察生态对环境变化的反应的复杂性。在上个世纪，溯河产卵的太平洋鲑鱼的种群动态受到区域气候、固有的密度依赖调节和渔业活动之间大规模变化的相互作用的影响。我们建议利用独特的，非常详细的生物和物理的时间序列，延长40-50年，以测试气候和生物过程之间的相互作用，在阿拉斯加西南部的红鲑鱼作为苗圃栖息地的淡水生态系统。红眼鱼不仅是该地区商业和生计社区的重要渔业资源，也是推动淡水和河岸生态系统许多组成部分的关键物种。我们建立了一系列工作假设来研究气候变量之间的相互作用（例如，水文学，冰消期）和生物变量（例如，熊捕食，幼鱼竞争），相互作用，以控制生活史的演变和红眼在淡水生态系统的生态。我们的主要研究主题是探索：1）栖息地特征、气候驱动的水文变化、熊捕食和鲑鱼密度之间的相互作用控制着成年红鲑的生活史模式和生产力，2）红鲑种群动态和气候是作为保育栖息地的湖泊中湖沼条件的控制因素，生物和气候因素控制红鲑幼鱼向海迁移的生长速度和年龄。红眼是此类研究的理想物种，因为它们在离散的生命史阶段占据溪流，湖泊和开阔海洋栖息地，对浮游动物群落施加自上而下的控制，在它们死亡和分解时为淡水生态系统提供重要的海洋来源的营养物质，并且在大型，经过充分研究的种群中出现。1）保持采样程序，以建立在四十多年前在阿拉斯加西南部布里斯托湾的两个湖泊系统中建立的现有数据集为基础，2）继续发展最先进的数据存档系统，以确保数据的长期安全，和3）启动新的回顾性研究，以测试对理解气候与红眼生态之间的相互作用至关重要的几个假设，他们的生态系统。一个主要目标是开发一个可供淡水生态学和渔业生物学各方面调查人员使用的活数据库。这些数据集包括成年红鲑的丰度、大小和年龄结构、区域气候、育苗湖的湖沼条件以及幼红鲑和其他湖泊鱼类的丰度和生长情况。更具体地说，我们将评估气候变化对鱼类生活史进化和种群动态的影响，这些鱼类在其生态系统的结构和功能以及该地区人民的当地经济和文化中发挥着极其重要的作用。

0128902QuinnDespite the general appreciation for climatic effects on ecological dynamics, most biologicalstudies are too brief to test for interactions between climatic and biological processes. Alternatively,many long-term studies do not span enough levels of biological organization to provide meaningfulinsights into the complexity of ecological responses to environmental change. In the last century,population dynamics of anadromous Pacific salmon have been influenced by interactions among large-scale shifts in regional climate, inherent density-dependent regulation, and fisheries activities. We propose to take advantage of unique, highly detailed biological and physical time series that extend for 40-50 years to test for interactions between climatic and biological processes in the freshwater ecosystems used as nursery habitats by sockeye salmon in southwestern Alaska. Sockeye are not only an important fishery resource to commercial and subsistence communities in this region, but are also keystone species, driving many components of freshwater and riparian ecosystems.We have established a series of working hypotheses to investigate interactions among climaticvariables (e.g., hydrology, ice-out date) and biological variables (e.g., bear predation, juvenilecompetition) that interact to control life history evolution and the ecology of sockeye in freshwaterecosystems. Our main research themes are to explore: 1) interactions among habitat features, climate-driven variation in hydrology, bear predation and salmon density controlling the life history patterns and productivity of adult sockeye, 2) sockeye population dynamics and climate as controllers of limnological conditions in lakes used as nursery habitats, and 3) biological and climatic factors controlling growth rates and age at seaward migration in juvenile sockeye salmon. Sockeye are an ideal species for such studies because they occupy stream, lake and open ocean habitats at discrete life history stages, exert top-down control on zooplankton communities, provide important marine-derived nutrients to freshwater ecosystems when they die and decompose, and occur in large, well-studied populations.This LTREB research will: 1) maintain sampling programs to build on existing data sets established over fourdecades ago in two lake systems of Bristol Bay, Southwest Alaska, 2) continue to develop a state-of-the-art data archive system to ensure long-term data security, and 3) initiate new and retrospective studies to test several hypotheses central to understanding the interactions between climate and the ecology of sockeye and their ecosystems. A major objective is to develop a living database available to investigators from all avenues of freshwater ecology and fisheries biology. These data sets include the abundance, size- and age-structure of adult sockeye salmon, regional climate, limnological conditions in nursery lakes, and abundance and growth of juvenile sockeye salmon and other lacustrine fishes. More specifically, we will evaluate the consequences of climate change for life history evolution and population dynamics of a fish species that plays an exceptionally important role in the structure and function of its ecosystems, and the local economy and culture of people in the region.