Arctic coastal lagoons are important habitats for unique assemblages of diadromous and marine fishes. Many of these fishes are vital to the food security of rural and indigenous communities. However, human impacts on coastal Arctic habitats, as well as climate change, weaken ecosystem resiliency and threaten the sustainability of fish stocks as a component of local food security. Identifying how habitat characteristics influence fish ecology may allow for predictions of changes in fish abundance and availability in response to these threats, and may help illuminate strategies for responding to negative impacts. Consequently, we endeavored to link habitat characteristics likely to be most-impacted by climate change to fish assemblage trophic metrics in four lagoons within Cape Krusenstern National Monument, Alaska where subsistence fishing commonly occurs. This was done through calculating trophic metrics including mean nitrogen (δ¹⁵N) and carbon (δ¹³C) stable isotope values from fish muscle tissue samples collected from the study lagoons. Lagoon habitat characteristics were quantified including ocean connectivity, freshwater input, and surface area using satellite imagery. Finally, associations between fish assemblage trophic metrics and habitat characteristics were evaluated using linear regressions, and trophic metrics were compared between lagoons with ANOVA and Tukey post-hoc tests. Model results showed that increased freshwater input resulted in longer duration of lagoon ocean connectivity. Additionally, longer duration of ocean connectivity was associated with an increase in mean δ¹⁵N and δ¹³C across all lagoon fish species. Finally, there were significant species-specific differences in fish trophic metrics among lagoons with varying habitat characteristics. Overall, freshwater input and ocean connectivity of coastal Arctic lagoons appear to be important drivers of fish trophic ecology, and should be carefully monitored in the face of anticipated changes in the region, to conserve important subsistence harvest species.

北极沿海泻湖是独特的洄游鱼类和海洋鱼类群落的重要栖息地。其中许多鱼类对农村和土著社区的粮食安全至关重要。然而，人类对北极沿海栖息地的影响以及气候变化削弱了生态系统的弹性，并威胁到作为当地粮食安全组成部分的鱼类种群的可持续性。确定栖息地特征如何影响鱼类生态可以预测鱼类数量和可用性的变化以应对这些威胁，并有助于阐明应对负面影响的策略。因此，我们努力将可能受气候变化影响最大的栖息地特征与克鲁森斯坦角国家纪念碑内四个泻湖中的鱼类组合营养指标联系起来，阿拉斯加经常发生自给性捕鱼。这是通过计算营养指标，包括平均氮（δ ¹⁵ N) 和碳 ( δ ¹³ C) 稳定同位素值来自从研究泻湖收集的鱼肌肉组织样本。泻湖栖息地特征被量化，包括海洋连通性、淡水输入和使用卫星图像的表面积。最后，使用线性回归评估鱼类组合营养指标与栖息地特征之间的关联，并使用方差分析和 Tukey 事后检验比较泻湖之间的营养指标。模型结果表明，增加的淡水输入导致泻湖海洋连通性的持续时间更长。此外，海洋连通性的持续时间延长与平均δ ¹⁵ N 和δ ¹³的增加有关C 涵盖所有泻湖鱼类。最后，具有不同栖息地特征的泻湖之间的鱼类营养指标存在显着的物种特异性差异。总体而言，北极沿海泻湖的淡水输入和海洋连通性似乎是鱼类营养生态的重要驱动因素，应对该地区的预期变化进行仔细监测，以保护重要的自给丰收物种。