Lake whitefish Coregonus clupeaformis play a key role in the socioeconomics of the Laurentian Great Lakes region and serve as an important conduit of energy among trophic levels. Lake wide declines in adult abundance creates the need for improved understanding of population dynamics, currently hampered by a lack of early life history information and resolution of subpopulation structure. We predicted that otolith microchemistry had the potential to broaden our understanding of lake whitefish ecology by determining the natal origin of larvae at a resolution (e.g., spawning location) unachievable with other techniques. To test this prediction, in 2017 and 2018, recently hatched, pelagically-drifting lake whitefish larvae were collected from the open waters of Green Bay, Lake Michigan and four large tributaries (Menominee, Fox, Oconto and Peshtigo Rivers), where spawning activity has been recently documented. Linear discriminant function analyses conducted at the broadest level of resolution (i.e., river vs. open-water origin) correctly assigned 80.5% and 75.0% of individuals to their natal location in 2017 and 2018, respectively. Reclassification success at a finer resolution (i.e., specific rivers) ranged from 75.9% in 2017 to 42.1% in 2018. We discuss these promising results with respect to underlying variation in geological features, water chemistry and interannual river conditions that eggs and larvae experience during incubation and before prolonged drift.

湖白鱼Coregonus clupeaformis在劳伦斯大湖区的社会经济中发挥着关键作用并作为营养级之间重要的能量管道。成鱼丰度在全湖范围内的下降需要更好地了解种群动态，目前由于缺乏早期生活史信息和亚种群结构解析而受到阻碍。我们预测耳石微化学有可能通过以其他技术无法实现的分辨率（例如产卵地点）确定幼虫的出生起源来拓宽我们对湖白鱼生态学的理解。为了验证这一预测，在 2017 年和 2018 年，从绿湾、密歇根湖和四个大型支流（梅诺米尼河、福克斯河、奥康托河和佩什蒂戈河）的开阔水域收集了最近孵化的远洋漂流湖白鱼幼虫，这些地方的产卵活动已经最近被记录在案。线性2017 年和 2018 年，在最广泛的分辨率水平（即河流与开放水域起源）上进行的判别函数分析分别正确地将 80.5% 和 75.0% 的个体分配到了他们的出生位置。更精细分辨率（即特定河流）的重新分类成功率从 2017 年的 75.9% 到 2018 年的 42.1%。我们讨论了这些有希望的结果，这些结果涉及地质特征、水化学和年际河流条件的潜在变化，这些变化是卵和幼虫在此期间经历的孵化和长期漂移之前。