Inter-Research > ESR > v54 > p93-104  
Endangered Species Research

via Mailchimp

ESR 54:93-104 (2024)  -  DOI:

Discriminating Canadian Arctic beluga management stocks using dentine oxygen and carbon isotopes

Cory J. D. Matthews1,*, Fred J. Longstaffe2, Geneviève J. Parent3, Claire A. Hornby1, Cortney A. Watt1

1Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, MB R3T 2N6, Canada
2Department of Earth Sciences, The University of Western Ontario, London, ON N6G 2V4, Canada
3Fisheries and Oceans Canada, 850 route de la Mer, Mont-Joli, QC G5H 3Z4, Canada
*Corresponding author:

ABSTRACT: In the eastern Canadian Arctic, belugas Delphinapterus leucas exhibit genetic and ecological differentiation across their distribution that forms the basis of management stocks for traditional Inuit hunts. Using oxygen and stable carbon isotope ratios in dentine phosphate (δ18OP) and structural carbonate (δ13CSC), respectively, we evaluated the spatial structure of 3 of these beluga stocks: Western Hudson Bay (WHB, n = 30), Cumberland Sound (CS, n = 44), and Eastern High Arctic-Baffin Bay (EHA-BB, n = 29). Pairwise comparisons revealed significant differences in δ18OP and Suess-adjusted δ13CSC among all stocks, with the exception of similar δ18OP between the WHB and CS stocks. A linear discriminant analysis (LDA) model fit to 60% of the data set (training data) successfully classified 84% of the remaining belugas (test data) to their respective stocks based on hunt location. Isotopic overlap among stocks could reflect (1) homogeneous baseline stable isotope (SI) composition between geographically adjacent stocks, (2) some degree of marginal geographic overlap in ranges or individual movements among stocks, perhaps during late spring, or (3) confounding dietary influences that increased within-stock SI variation. Some misclassifications consistent with individual movements among stocks were supported by limited genetic data, with a small number of belugas hunted from the CS stock exhibiting both isotopic and genetic similarity to WHB belugas. Geographic stock differentiation inferred from oxygen and carbon isotope proxies largely corroborates current eastern Canadian Arctic beluga stock definitions, which is relevant not only for management purposes but also for monitoring changing beluga distributions in response to ongoing climate-driven changes in Arctic marine ecosystems.

KEY WORDS: Biogeography · Bioapatite · Delphinapterus leucas · Distribution · Ecography · Isoscape · Stock assessment

Full text in pdf format
Supplementary material
Cite this article as: Matthews CJD, Longstaffe FJ, Parent GJ, Hornby CA, Watt CA (2024) Discriminating Canadian Arctic beluga management stocks using dentine oxygen and carbon isotopes. Endang Species Res 54:93-104.

Export citation
Share:    Facebook - - linkedIn

 Previous article Next article