Plasticity of Life History Traits in Arctic Charr: Use of Retrospective Data to Couple Migration Data with Environmental Variation

形态和环境历史之间的关系将被调查。研究计划旨在1)完善和推进有前途的新技术，从碳酸盐耳石和档案标签中提取个体鱼类过去生活史和环境条件的记录；2)通过将实验验证的耳石技术应用于多种自然条件下的个体，探索一种新的方法来研究环境条件对形态和生活史可塑性的影响。目标是建立耳石化学结构与环境因素之间的回顾性和预测性关系：了解影响化学结构的环境因素之间的相互作用；并将耳石编码的环境信息与野外观测相结合，评估生物和非生物参数对建立北极地区不同生活史模式的重要性。每日生长增量，耳石中元素的比例和档案标签信息将用于反算单个鱼的环境和体细胞变化。技术将应用于：1)根据生活史策略评估生活史数据（即生长速度，年龄结构，孵化日期分布，产卵时间等）。2)通过调查鱼类耳石的结构和元素组成，确定关键生活史转变的重要性，影响其开始的条件，并得出迁徙方案（个体是迁徙者还是居民，首次迁徙的年龄，前迁徙个体是否会恢复居民生活史策略，以及导致和随后迁移的事件）。3)发现不同地理区域之间与水文、营养或生境条件有关的生长和生活史差异。4)精确确定几个关键生活史转变发生的时间，并将它们与环境变量联系起来。研究结果将为鱼类生活史的研究提供一个范例。这些知识对于我们理解适应性生命史模式的基本过程至关重要，并将使我们有可能将生长和迁移与环境事件联系起来。这将为物种与其环境之间相互作用的生态过程提供洞见。在一般的生态学意义上，这种信息具有重大和根本的重要性，因为它将使我们能够重建个体之间复杂的环境相互作用，从而为个体、种群和物种的家庭提供短期稳定和长期进化。

The relationships between morphology and environmental history will be investigated. The plan of research is aimed at 1) refining and advancing promising, but nascent, techniques for extracting a record of the past life history and environmental conditions encountered by individual fish from otolith carbonate and archival tags, and 2) exploring a fresh approach to investigate the influence of environmental conditions upon morphology and life history plasticity by applying experimentally validated otolith techniques to individuals from a multitude of natural conditions. The goals are to establish retrospective and predictive relationships between the chemical structure of otoliths and environmental factors: to understand interactions among environmental factors that affect chemical structure; and to combine the environmental information encoded in otoliths with field observations to evaluate the importance of biotic and abiotic parameters to the establishment of divergent life history patterns in Arctic charr. Daily growth increments, the ratios of elements in the otolith and archival tag information will be used to back-calculate environmental and somatic changes for individual fish. Techniques will be applied to: 1) Assess life history data (i.e., growth rates, age structure, hatch date distribution, timing of spawning, etc.) in terms of life history strategies. 2) Establish the importance of critical life-history transitions, conditions affecting their onset, and derive migrational schemes (whether an individual is a migrant or a resident, age at first migration, whether a former migrant individual will resume a resident life history strategy, and the events leading and following migration) by investigating the structural and elemental composition of fish otoliths. 3) Detect differences in growth and life histories between different geographical areas as related to hydrographic, trophic or habitat conditions. 4) Precisely time the occurrence of several pivotal life history transitions and correlate them with environmental variables. The results of the proposed research will provide a paradigm to the study of fish life histories. Such knowledge is vital to our understanding of the processes fundamental to adaptable life history patterns and would make it possible to link growth and migration to environmental occurrences. This would provide insight to the ecological process of interactions between a species and its environment. In a general ecological sense such information is of great and fundamental importance since it will allow to reconstruct the complex environmental interactions that are integrated among individuals to provide for both the short term stability and the long term evolution of families of individuals, populations and species.