Coregonine fishes are important to Laurentian Great Lakes food webs and fisheries and are central to basin-wide conservation initiatives. In Lake Ontario, binational management objectives include conserving and restoring spawning stocks of cisco (Coregonus artedi) and lake whitefish (C. clupeaformis), but the spatial extent of contemporary coregonine spawning habitat and the environmental factors regulating early life success are not well characterized. In Spring 2018, we conducted a binational ichthyoplankton assessment to describe the spatial extent of coregonine spawning habitat across Lake Ontario. We then quantified the relative importance of a suite of biophysical variables hypothesized to influence coregonine early life success using generalized additive mixed models and multimodel inference. Between April 10 and May 14, we conducted 1,092 ichthyoplankton tows and captured 2,350+ coregonine larvae across 17 sampling areas, predominantly within embayments. Although 95% of catches were in the eastern basin, coregonine larvae were also found in historical south shore spawning areas. Most coregonine larvae were cisco; <6% were lake whitefish. Observed catches of both species across sampling areas were strongly and similarly associated with ice cover duration, but the importance of site-specific characteristics varied, such as distance to shore and site depth for cisco and lake whitefish, respectively. These results suggest that regional-scale climatic drivers and local environmental habitat characteristics interact to regulate early life stage success. Furthermore, strong regional and cross-species variation in larval distributions emphasize the importance of lake-wide assessments for monitoring both the current eastern basin populations and potential expansions into western Lake Ontario habitats.

Coregonine 鱼类对 Laurentian Great Lakes 的食物网和渔业非常重要，是整个流域保护计划的核心。在安大略湖，两国管理目标包括保护和恢复产卵种群 cisco ( Coregonus artedi ) 和湖白鲑 ( C. clupeaformis），但当代考根宁产卵栖息地的空间范围和调节早期生命成功的环境因素没有得到很好的表征。在 2018 年春季，我们进行了一项两国浮游鱼类评估，以描述整个安大略湖的 coregonine 产卵栖息地的空间范围。然后，我们使用广义加性混合模型和多模型推理，量化了一组假设影响 coregonine 早期生命成功的生物物理变量的相对重要性。在 4 月 10 日至 5 月 14 日期间，我们在 17 个采样区域（主要是在海湾内）进行了 1,092 条浮游鱼类拖曳，并捕获了 2,350 多只考戈宁幼虫。虽然 95% 的渔获量都在东部盆地，但在历史悠久的南岸产卵区也发现了考戈宁幼虫。大多数coregonine幼虫是cisco；< 6% 是湖白鲑。在采样区域观察到的两种物种的捕捞量与冰盖持续时间密切相关，并且相似，但特定地点特征的重要性各不相同，例如到海岸的距离和思科和湖白鲑的地点深度。这些结果表明，区域尺度的气候驱动因素和当地环境栖息地特征相互作用以调节早期生命阶段的成功。此外，幼虫分布的强烈区域和跨物种差异强调了全湖评估对于监测当前东部流域种群和安大略湖西部栖息地潜在扩张的重要性。但特定地点特征的重要性各不相同，例如离岸距离和地点深度分别为思科和湖白鲑。这些结果表明，区域尺度的气候驱动因素和当地环境栖息地特征相互作用以调节早期生命阶段的成功。此外，幼虫分布的强烈区域和跨物种差异强调了全湖评估对于监测当前东部流域种群和安大略湖西部栖息地潜在扩张的重要性。但特定地点特征的重要性各不相同，例如离岸距离和地点深度分别为思科和湖白鲑。这些结果表明，区域尺度的气候驱动因素和当地环境栖息地特征相互作用以调节早期生命阶段的成功。此外，幼虫分布的强烈区域和跨物种差异强调了全湖评估对于监测当前东部流域种群和安大略湖西部栖息地潜在扩张的重要性。