Data from: Dietary plasticity and broad North Atlantic origins inferred from bulk and amino acid-specific δ15N and δ13C favor killer whale range expansions into Arctic waters ...

• Main Authors: Matthews, Cory, Yarnes, Chris, Lefort, Kyle, Edkins, Tera, Kiszka, Jeremy, Ferguson, Steven
• Format: Dataset
• Language: English
• Published: Dryad 2024
• Subjects: essential amino acid; Phenylalanine; compound specific stable isotope analysis CSIA; Orcinus orca; Threonine; Trophic; source; FOS Biological sciences; Baffin Island; Baffin; baleen whales; Killer Whale; North Atlantic; Orca; Sea ice; Killer whale
• Online Access: https://dx.doi.org/10.5061/dryad.0zpc8675r; https://datadryad.org/stash/dataset/doi:10.5061/dryad.0zpc8675r

Killer whales (Orcinus orca) occur seasonally in the eastern Canadian Arctic (ECA), where their range expansion associated with declining sea ice have raised questions about the impacts of increasing killer whale predation pressure on Arctic-endemic prey. We assessed diet and distribution of ECA killer whales using bulk and compound specific stable isotope analysis (CSIA) of amino acids (AA) of 54 skin biopsies collected from 2009-2020 around Baffin Island, Canada. Bulk ECA killer whale skin δ15N and δ13C values did not overlap with potential Arctic prey after adjustment for trophic discrimination, and instead reflected foraging history in the North Atlantic prior to their arrival in the ECA. Adjusted killer whale stable isotope (SI) values primarily overlapped with several species of North Atlantic baleen whales or tuna. Amino acid (AA)-specific δ15N values indicated the ECA killer whales fed primarily on marine mammals, having similar glutamic acid δ15N – phenylalanine δ15N (δ15NGlx-Phe) and threonine δ15N ... : All details in associated manuscript. ...