Diet and trophic ecology of introduced salmonines at two south shore ports of Lake Superior, 2019

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