Life History Trait Plasticity and Adaptations to Stochastic Environmental Divergences: High Arctic Charr

本项目是一项跨学科研究，旨在验证气候和栖息地随机变化在北极高海拔淡水系统北极鲑（Salvelinus alpinus）生活史特征、适应机制和种群组成发展中起决定性作用的假设。该研究将地球物理观测与生态学、回顾性和遗传学研究相结合。北极圈是研究环境因素如何影响鱼类生活史、种群结构和多样性的理想场所。Charr种群表现出巨大的生态可塑性和对恶劣环境的适应性。北极鲑是北极高纬度地区唯一的淡水鱼，和其他地方一样，它有着广泛的生活史策略，包括溯河种群、常驻种群和内陆种群。在具有迁徙性的湖泊系统中，种群可能由幼、幼后和成年迁徙性个体混合组成，也可能由小型常驻个体、大型常驻个体和大型原常驻个体组成。环境对表现型、基因型和生活史的影响取决于环境条件、发育率、遗传信息、迁移率和极端条件下死亡率的详细信息。在本研究中，将比较来自图勒、迪斯科、努克和朱利安哈布、格陵兰岛和加拿大埃尔斯米尔岛地区湖泊系统的charr种群。Charr在所有系统中都经历高度随机的环境。尽管与迁徙有关的适应性、遗传和行为机制在低纬度鲑科鱼类中是众所周知的，但对生活在高纬度环境中的溯河鲑的这种机制的了解仍然是零碎的。一般来说，与季节事件相关的机制必须是预适应的。这种预适应机制如何与高北极系统中允许碳迁移的不可预测的物理条件同步并受其影响，将是本项目的主要主题。

This project represents an interdisciplinary study to test the hypothesis that stochastic climate and habitat variation play a decisive role in the development of life history traits, adaptation mechanisms and population composition in Arctic charr (Salvelinus alpinus) in high Arctic freshwater systems. The study combines geophysical observations with ecological, retrospective and genetic studies. The circumpolar Arctic charr is ideal for the study of how environmental factors affect life history, population structure and diversity in fishes. Charr populations demonstrate a tremendous ecological plasticity and adaptations to harsh environments. Arctic charr is the only freshwater fish in the high Arctic and, as elsewhere, has a broad range of life-history strategies including anadromous, resident and landlocked populations. In lake systems with migrating charr, the population may consist of a mixture of parr, postsmolt and adult migratory individuals, as well as small-sized resident, large-sized resident and large formerly resident individuals transformed to anadromy. Determination of the effect of the environment upon phenotype, genotype and life history relies upon detailed information about environmental conditions, developmental rates, genetic information, migration rates and mortality in extreme conditions. In this study charr populations from lake systems from the Thule, Disko, Nuuk and Julianehaab, Greenland and Ellesmere Island, Canada areas will be compared. Charr in all systems experience highly stochastic environments. Whereas adaptive, genetic and behavioral mechanisms associated with migration are well known for salmonid fish at lower latitudes, knowledge about such mechanisms in anadromous charr inhabiting high latitude environments are still fragmentary. In general, mechanisms associated with seasonal events must be pre-adaptive. How such pre-adaptive mechanisms are timed with, and influenced by, the unpredictable physical conditions allowing for charr migration in high Arctic systems will be the main topic of this propject.