Advertisement
Browse Subject Areas
?

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here.

  • Loading metrics

Open Access

Editorial Note

Editorial Notes are published by PLOS to provide readers information relevant to an article’s interpretation.

See all article types »

Editorial Note: Prevalence of Chinook salmon is higher for southern than for northern resident killer whales in summer hot-spot feeding areas

  • The PLOS One Editors

After publication of this article [1], concerns were raised by a reader about the interpretation of the study’s findings and the information provided regarding killer whale prey availability and foraging activity. After editorial follow-up with the authors and consulting a member of the Editorial Board with expertise in population data analysis, the PLOS One Editors assessed these concerns and consider that the article’s findings remain supported. This Editorial Note is issued to clarify points raised during post‑publication assessment and to provide additional information regarding comparisons with earlier research, study limitations, and the rationale for site selection.

1. Comparison with previous research

Based on input received during editorial follow-up, the PLOS One Editors consider that the study reported in [1] is complementary to the body of research suggesting food limitation in southern resident killer whales (SRKWs) [2–4]. The member of the Editorial Board noted that divergence between the study reported in [1] and expectations based on this prior research highlights the need for continued investigation into the seasonal and regional context of prey availability for SRKWs.

The last author stated that they are in agreement with prior findings that SRKWs are food limited, but noted that the study in [1] was designed to determine whether the food shortage was occurring during the summer when SRKWs typically travel north to the Salish Sea to feed, or whether it could be occurring at other limiting times of year such as winter or spring. They further noted that they consider the findings reported in [1] augment previous knowledge, but direct comparisons between studies are limited owing to differing study scopes, data types, and seasonal coverage.

2. Study limitations

The study relies in part on information obtained from whale‑watching professionals and professional sport fishermen for site selection; a member of the Editorial Board noted this may introduce potential bias affecting the representativeness of selected foraging hot‑spot locations. It was further noted that some of the feeding hotspot information used in this study [1] differed compared to prior reports identifying feeding and foraging areas [5–7]. The member of the Editorial Board noted that further research will be required to validate information obtained from whale-watching professionals and fishermen. Other key limitations related to undersampling foraging hot spots relative to the full spatial and temporal ranges used by resident killer whales, and constraints associated with conducting a single-season survey are discussed in [1].

Based on information provided by the last author, this notice provides the following additional information regarding study site selection:

Two study sites were selected, the Salish Sea and North Island Waters, because they are important and well-documented feeding areas used by resident killer whales during summer [8–10] that have historically been the focus of the majority of field studies on both SRKWs and NRKWs [11–16]. Hot-spot feeding locations within each region were identified through consultations with experienced whale-watching professionals and full-time sport fishermen. These individuals were asked to annotate independent nautical charts to respectively indicate areas of high killer whale feeding activity or areas of high Chinook salmon numbers. Congruence between the independently created maps provided validation of site selection. The authors consider their consultations with fishermen and whale‑watching professionals a major strength that informed the study’s design and findings.

References

  1. 1. Saygili B, Trites AW. Prevalence of Chinook salmon is higher for southern than for northern resident killer whales in summer hot-spot feeding areas. PLoS One. 2024;19(10):e0311388. pmid:39388449
  2. 2. Ford JKB, Ellis GM, Olesiuk PF, Balcomb KC. Linking killer whale survival and prey abundance: food limitation in the oceans’ apex predator?. Biol Lett. 2010;6(1):139–42. pmid:19755531
  3. 3. Ward EJ, Holmes EE, Balcomb KC. Quantifying the effects of prey abundance on killer whale reproduction. J Appl Ecol. 2009;46(3):632–40.
  4. 4. Ward EJ, Ford MJ, Kope RG, Ford JKB, Vélez‑Espino LA, Parken CK, et al. Estimating the impacts of Chinook salmon abundance and prey removal by ocean fishing on Southern Resident killer whale population dynamics. NOAA Tech Memo NMFS‑NWFSC‑123. 2013: i–x, 71 p. Available from: https://repository.library.noaa.gov/view/noaa/4527
  5. 5. Noren DP, Hauser DDW. Surface‑based observations can be used to assess behavior and fine‑scale habitat use by an endangered killer whale (Orcinus orca) population. Aquat Mamm. 2016;42(2):168–83.
  6. 6. Hanson M, Baird R, Ford J, Hempelmann-Halos J, Van Doornik D, Candy J, et al. Species and stock identification of prey consumed by endangered southern resident killer whales in their summer range. Endang Species Res. 2010;11:69–82.
  7. 7. Thornton SJ, Toews S, Stredulinsky E, Gavrilchuk K, Konrad CM, Burnham R, et al. Southern Resident killer whale (Orcinus orca) summer distribution and habitat use in the southern Salish Sea and Swiftsure Bank area (2009 to 2020). 2022/037. 2022.
    • 8. Ford JKB. An assessment of critical habitats of resident killer whales in waters off the Pacific coast of Canada. 2006/072. 2006.
      • 9. Ford JKB, Pilkington JF, Reira A, Otsuki M, Gisborne B, Abernethy RM. Habitats of special importance to resident killer whales (Orcinus orca) off the west coast of Canada. 2017/035. 2017.
        • 10. Ford JKB, Ellis GM. Selective foraging by fish-eating killer whales Orcinus orca in British Columbia. Mar Ecol Prog Ser. 2006;316:185–99.
        • 11. Wright BM, Ford JKB, Ellis GM, Deecke VB, Shapiro AD, Battaile BC, et al. Fine-scale foraging movements by fish-eating killer whales (Orcinus orca) relate to the vertical distributions and escape responses of salmonid prey (Oncorhynchus spp.). Movement Ecology. 2017;5:3.
        • 12. Wright BM, Deecke VB, Ellis GM, Trites AW, Ford JKB. Behavioral context of echolocation and prey-handling sounds produced by killer whales (Orcinus orca) during pursuit and capture of Pacific salmon (Oncorhynchus spp.). Mar Mamm Sci. 2021;37(4):1428–53. pmid:34690418
        • 13. Tennessen JB, Holt MM, Wright BM, Hanson MB, Emmons CK, Giles DA, et al. Males miss and females forgo: Auditory masking from vessel noise impairs foraging efficiency and success in killer whales. Glob Chang Biol. 2024;30(9):e17490. pmid:39254237
        • 14. Tennessen JB, Holt MM, Wright BM, Hanson MB, Emmons CK, Giles DA, et al. Divergent foraging strategies between populations of sympatric matrilineal killer whales. Behav Ecol. 2023;34(3):373–86. pmid:37192928
        • 15. McRae TM, Volpov BL, Sidrow E, Fortune SME, Auger-Méthé M, Heckman N, et al. Killer whale respiration rates. PLoS One. 2024;19(5):e0302758. pmid:38748652
        • 16. Sato M, Trites AW, Gauthier. Southern resident killer whales encounter higher prey densities than northern resident killer whales during summer. Can J Fish Aquat Sci. 2021;78:1732–43.

        Citation: The PLOS One Editors (2026) Editorial Note: Prevalence of Chinook salmon is higher for southern than for northern resident killer whales in summer hot-spot feeding areas. PLoS One 21(7): e0353511. https://doi.org/10.1371/journal.pone.0353511

        Published: July 13, 2026

        Copyright: © 2026 The PLOS One Editors. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.