Natal Origin of Juvenile Salmon Collected on Middleton Island, Alaska, 2010-2024

This dataset provides origin (hatchery vs. wild) and energy density (kJ g-1) of juvenile pink (Oncorhynchus gorbuscha) and chum salmon (O. keta) from the eastern Gulf of Alaska, 2010–2024. Juvenile salmon were sampled from rhinoceros auklet (Cerorhinca monocerata) diets on Middleton Island (59.4375 N, 146.3277 W) located near the continental shelf break in the Gulf of Alaska. Auklets generally forage within 100 km of the colony and bring whole fish back to provision their chicks during July and August. Hatchery/wild origin was derived from identification of hatchery thermal marks on the sagittal otolith. Energy density was measured by bomb calorimeter for a subset of these fish.