University of Oulu

Wolf, Nathan; Webster, Sarah R.; Welker, Jeffery M.; Harris, Bradley P. Assessing the relationship between diet and size-at-age in Pacific halibut (Hippoglossus stenolepis) using δ13C and δ15N analysis. Canadian Journal of Fisheries and Aquatic Sciences, 2019, 76(12): 2326-2331,

Assessing the relationship between diet and size-at-age in Pacific halibut (Hippoglossus stenolepis) using δ₁₃C and δ₁₅N analysis

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Author: Wolf, Nathan1; Webster, Sarah R.1; Welker, Jeffery M.2,3;
Organizations: 1Fisheries Aquatic Science and Technology (FAST) Laboratory, Alaska Pacific University, University Drive, Anchorage, AK 99508, USA
2Department of Biological Sciences, University of Alaska Anchorage, Providence Drive, Anchorage, AK 99508, USA
3UArctic – Ecology and Genetics Research Unit, University of Oulu, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.4 MB)
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Language: English
Published: Canadian Science Publishing, 2019
Publish Date: 2020-02-13


The ecological mechanisms driving an observed decline in the mean size-at-age of adult Pacific halibut (Hippoglossus stenolepis) in the eastern North Pacific Ocean have yet to be defined. Here, we present the results of a study designed to investigate the relationship between one potential mechanism — diet — and size-at-age using carbon and nitrogen stable isotope analysis. Our results indicate significant differences in the skeletal muscle δ₁₃C and δ₁₅N values between size-at-age categories for each sex, with larger-size-at-age fish consuming diets with higher δ₁₅N values, indicating higher trophic level feeding. Analysis of Bayesian standard ellipse areas showed that for females, intermediate size-at-age categories have the largest dietary range. For males, the largest dietary range was observed in the largest size-at-age category. Our results suggest a size-based stratification in dietary strategy for Pacific halibut with implications for observed declines in size-at-age.

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Series: Canadian journal of fisheries and aquatic sciences
ISSN: 0706-652X
ISSN-E: 1205-7533
ISSN-L: 0706-652X
Volume: 76
Issue: 12
Pages: 2326 - 2331
DOI: 10.1139/cjfas-2018-0380
Type of Publication: A1 Journal article – refereed
Field of Science: 1181 Ecology, evolutionary biology
Funding: Support for this work was provided by Alaska Education Tax Credit funds contributed by the At-Sea Processors Association and the Groundfish Forum.
Copyright information: Copyright remains with the author(s) or their institution(s). The final authenticated version is available online at