Though aquatic ecosystems (and the Laurentian Great Lakes in particular) have faced many stressors over the past century, including fisheries collapses and species invasions, rarely are data available to evaluate the long-term impacts of these stressors on food web structure. Stable isotopes of fish scales from the 1940s to the 2010s in South Bay, Lake Huron were used to quantify trophic position and resource utilization for fishes from offshore (alewife, cisco, lake trout, lake whitefish, rainbow smelt) and nearshore (rock bass, smallmouth bass, white sucker, yellow perch) habitats, providing one of the longest continuous characterizations of food webs in the Laurentian Great Lakes. Mean δ¹⁵N and δ¹³C values for each species were compared across twenty-year time periods. Using directional statistics, no significant community-wide changes were detected between time periods from 1947 to 1999. In contrast, a significant change was detected between 1980-1999 and 2000–2017, with all species showing increased reliance on nearshore resources. The increase in nearshore resource reliance for lake whitefish between these time periods was the greatest in magnitude compared with any other species between any two adjacent time periods. Besides lake whitefish, the increased reliance on nearshore resources was more pronounced for nearshore compared to offshore species. The timing of these shifts coincided with the invasion of dreissenid mussels and round goby, and declines in offshore productivity and prey densities. These results show the unprecedented magnitude of recent food-web change in Lake Huron after 50 years of relative stability.

尽管水生生态系统（尤其是劳伦森五大湖）在过去一个世纪中面临着许多压力源，包括渔业崩溃和物种入侵，但很少有数据可用于评估这些压力源对食物网结构的长期影响。从 1940 年代到 2010 年代，休伦湖南湾鱼鳞的稳定同位素被用于量化近海（鲈鱼、cisco、湖鳟、湖白鲑、虹鳟鱼）和近岸（鲈鱼、小嘴鲈鱼、白吸盘、黄鲈）栖息地，提供了劳伦森五大湖中食物网最长的连续特征之一。平均 δ ¹⁵ N 和 δ ¹³在 20 年的时间段内比较了每个物种的 C 值。使用定向统计数据，在 1947 年至 1999 年期间未检测到显着的社区范围变化。相比之下，在 1980-1999 年和 2000-2017 年期间检测到显着变化，所有物种都显示出对近岸资源的依赖增加。与任何两个相邻时间段之间的任何其他物种相比，这些时间段之间对湖白鱼的近岸资源依赖的增加幅度最大。除了湖白鱼之外，与近海物种相比，近岸鱼类对近岸资源的依赖增加更为明显。这些转变的时机恰逢德莱森贻贝和圆虾虎鱼的入侵，以及近海生产力和猎物密度的下降。