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
Data files
Jun 10, 2024 version files 27.16 KB
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DRYAD_CSIA-AA_and_BULK_d15N_d13C_Matthews_et_al.xlsx
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README.md
Abstract
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 (δ15NThr) as mammal-eating killer whales from the eastern North Pacific (ENP) that served as a comparative framework. However, one ECA whale grouped with the fish-eating ENP ecotype based δ15NThr. Distinctive essential AA δ13C of ECA killer whale groups, along with bulk SI similarity to killer whales from different regions of the North Atlantic, indicate different populations converge in Arctic waters from a broad source area. Generalist diet and long-distance dispersal capacity favor range expansions, and integration of these insights will be critical for assessing ecological impacts of increasing killer whale predation pressure on Arctic-endemic species.
README: 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
https://doi.org/10.5061/dryad.0zpc8675r
This dataset includes amino acid specific and bulk stable nitrogen and carbon isotope measurements of lipid extracted from killer whale skin. The skin samples were collected from wild killer whales around Baffin Island, Canada, using standard biopsy techniques. All relevant collection data and permits are provided in the associated manuscript.
Description of the data and file structure
The Excel file is divided into two pages, one with the amino acid specific data and the other with the bulk tissue data (lipid extracted). Rows are individual whales, while columns are the measurements (d15N and d13C). All data in this Excel file are also presented in the manuscript, either directly or as supplementary information. All analytical details are provided in the associated manuscript.
Code/Software
All analyses were done using basic commands in R that can be readily replicated in any software program.
Methods
All details in associated manuscript.