Spatiotemporal variation in foraging ecology and mercury concentrations in ringed seals and bearded seals across a latitudinal gradient in the eastern Canadian Arctic.
| Title: | Spatiotemporal variation in foraging ecology and mercury concentrations in ringed seals and bearded seals across a latitudinal gradient in the eastern Canadian Arctic. |
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| Authors: | Laing RJ; Arctic Ecosystem Science Division, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, R3T 2N6, Canada; Department of Biology, University of Winnipeg, 515 Portage Ave, Winnipeg, Manitoba, R3B 2E9, Canada. Electronic address: janelle.laing@dfo-mpo.gc.ca.; Desforges JW; Department of Environmental Studies and Sciences, University of Winnipeg, 515 Portage Ave, Winnipeg, Manitoba, R3B 2E9, Canada.; Strong KS; Arctic Ecosystem Science Division, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, R3T 2N6, Canada.; Armstrong D; Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, 66 Chancellors Circle, Winnipeg, Manitoba, R3T 2N2, Canada.; Wang F; Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, 66 Chancellors Circle, Winnipeg, Manitoba, R3T 2N2, Canada.; Ferguson SH; Arctic Ecosystem Science Division, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, R3T 2N6, Canada.; Yurkowski DJ; Arctic Ecosystem Science Division, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, R3T 2N6, Canada. |
| Source: | Environmental research [Environ Res] 2025 Nov 15; Vol. 285 (Pt 3), pp. 122437. Date of Electronic Publication: 2025 Jul 24. |
| Publication Type: | Journal Article |
| Language: | English |
| Journal Info: | Publisher: Elsevier Country of Publication: Netherlands NLM ID: 0147621 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1096-0953 (Electronic) Linking ISSN: 00139351 NLM ISO Abbreviation: Environ Res Subsets: MEDLINE |
| Imprint Name(s): | Publication: : Amsterdam : Elsevier; Original Publication: New York, Academic Press. |
| MeSH Terms: | Seals, Earless*/physiology ; Seals, Earless*/metabolism ; Mercury*/analysis ; Mercury*/metabolism ; Water Pollutants, Chemical*/metabolism ; Water Pollutants, Chemical*/analysis; Animals ; Arctic Regions ; Canada ; Feeding Behavior ; Environmental Monitoring ; Climate Change ; Ecosystem ; Nitrogen Isotopes ; Spatio-Temporal Analysis ; Food Chain |
| Abstract: | Climate change is causing a decrease in Arctic sea ice extent and thickness, leading to alterations in interspecific interactions, food availability, and contaminant exposure for marine organisms, including higher trophic level predators such as ringed seals (Pusa hispida, natsiq) and bearded seals (Erignathus barbatus, ujjuk) who forage in disparate habitats. Despite rapid Arctic ecosystem change, spatiotemporal variability in the foraging behavior and contaminant dynamics of these Arctic seals remains poorly understood. Using stable isotopes (δ13C, δ15N, δ34S) and total mercury (THg) concentrations in claw annuli, we investigated spatiotemporal variability in the foraging ecology and contaminant exposure of ringed and bearded seals in relation to environmental factors at the individual, species, and between-species levels across a latitudinal gradient in the eastern Canadian Arctic. Overall, ringed seals fed more pelagically and had higher THg levels than bearded seals. A latitudinal gradient emerged where seals at lower latitudes had lower δ15N and THg, and foraged more pelagically than seals at higher latitudes. Bearded seals, and seals at lower latitudes, had higher degrees of individual specialization calculated using individual and population isotope variance analysis, suggesting they are more vulnerable to rapid environmental changes than ringed seals and seals at higher latitudes. Additionally, seals consumed relatively more pelagic prey in years with longer open water periods, supporting evidence of climate-induced shifts in Arctic marine mammal foraging strategies towards pelagic prey. This study provided insight into spatial variation in foraging strategies, habitat use, and contaminant exposure of two Arctic marine predators; information which can be used to inform species management and conservation efforts.; (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.) |
| Competing Interests: | Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. |
| Substance Nomenclature: | FXS1BY2PGL (Mercury); 0 (Water Pollutants, Chemical); 0 (Nitrogen Isotopes) |
| Entry Date(s): | Date Created: 20250727 Date Completed: 20251017 Latest Revision: 20251017 |
| Update Code: | 20260130 |
| DOI: | 10.1016/j.envres.2025.122437 |
| PMID: | 40713990 |
| Database: | MEDLINE |
Journal Article