Introduced salmonines (Oncorhynchus spp. and Salmo spp.) are important components of recreational fisheries in the Great Lakes. These fishes were stocked heavily following the fishery collapse of lake trout (Salvelinus namaycush) due to sea lamprey (Petromyzon marinus) predation and commercial overharvest. While salmonine introductions occurred in all five of the Great Lakes, Lake Superior is less productive than the lower Great Lakes restricting most introduced salmonines to a small percentage of available habitat. This suggests the potential for high resource overlap between salmonines, yet little information has been published related to the trophic ecology of introduced salmonines in Lake Superior. Furthermore, hybrid splake (S. namaycush × S. fontinalis) are also stocked by various state agencies while little information on their trophic ecology exists. To address uncertainties associated with introduced salmonines, we assessed the diet composition and isotopic niche overlap of fish collected from two south shore ports of Lake Superior. Introduced salmonines consumed similar prey items including rainbow smelt (Osmerus mordax), coregonines, and three-spined stickleback (Gasterosteus aculeatus) in varying amounts, with a notable percentage of diet comprising terrestrial invertebrates. These results are further supported by stable isotope analysis which indicated high isotopic niche overlap among introduced salmonines suggesting a mixed diet attributed to benthic, pelagic, and terrestrial sources. Our characterization of the salmonine community provides important information that will inform fisheries research and management in Lake Superior.

引进的鲑鱼（Oncorhynchus spp. 和Salmo spp.）是五大湖休闲渔业的重要组成部分。由于海七鳃鳗 ( Petromyzon marinus ) 的捕食和商业过度捕捞，在湖鳟 ( Salvelinus namaycush )渔业崩溃之后，这些鱼类被大量放养。虽然所有五个五大湖都引入了鲑鱼，但苏必利尔湖的生产力低于五大湖下游，将大多数引入的鲑鱼限制在一小部分可用栖息地。这表明鲑鱼之间存在高度资源重叠的潜力，但与苏必利尔湖引入的鲑鱼的营养生态相关的信息很少。此外，混合飞溅（S. namaycush  ×  S. fontinalis ) 也由各州机构储存，但关于其营养生态学的信息很少。为了解决与引入的鲑鱼相关的不确定性，我们评估了从苏必利尔湖的两个南岸港口收集的鱼类的饮食成分和同位素生态位重叠。引入的鲑鱼食用了类似的猎物，包括彩虹鱼( Osmerus mordax )、coregonines 和三刺棘鱼 ( Gasterosteus aculeatus)) 的数量各不相同，其中很大比例的饮食包括陆生无脊椎动物。这些结果得到稳定同位素分析的进一步支持，稳定同位素分析表明引入的鲑鱼之间的同位素生态位高度重叠，表明底栖、远洋和陆地来源的混合饮食。我们对鲑鱼群落的描述提供了重要信息，可为苏必利尔湖的渔业研究和管理提供信息。