Spatial segregation and similar trophic-level diet among eastern Canadian Arctic/north-west Atlantic killer whales inferred from bulk and compound specific isotopic analysis
Killer whales in the Eastern Canadian Arctic (ECA) prey on narwhal, beluga, bowhead whales and seals, while further south in the north-west Atlantic (NWA), killer whales off the coast of Newfoundland and Labrador prey on both marine mammals and fish. Bulk and amino acid (AA) specific isotopic compos...
Published in: | Journal of the Marine Biological Association of the United Kingdom |
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Online Access: | http://dx.doi.org/10.1017/s0025315413001379 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315413001379 |
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crcambridgeupr:10.1017/s0025315413001379 2024-10-20T14:06:55+00:00 Spatial segregation and similar trophic-level diet among eastern Canadian Arctic/north-west Atlantic killer whales inferred from bulk and compound specific isotopic analysis Matthews, Cory J.D. Ferguson, Steven H. 2013 http://dx.doi.org/10.1017/s0025315413001379 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315413001379 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Journal of the Marine Biological Association of the United Kingdom volume 94, issue 6, page 1343-1355 ISSN 0025-3154 1469-7769 journal-article 2013 crcambridgeupr https://doi.org/10.1017/s0025315413001379 2024-10-09T04:02:04Z Killer whales in the Eastern Canadian Arctic (ECA) prey on narwhal, beluga, bowhead whales and seals, while further south in the north-west Atlantic (NWA), killer whales off the coast of Newfoundland and Labrador prey on both marine mammals and fish. Bulk and amino acid (AA) specific isotopic composition of dentinal collagen in teeth of 13 ECA/NWA killer whales were analysed to assess the degree, if any, of dietary specialization of killer whales across the region. Dentine was sampled from within annual growth layer groups (GLGs) to construct chronological profiles of stable nitrogen (δ 15 N) and carbon (δ 13 C) isotopic compositions for individual whales spanning 3–25 years. Interannual isotopic variation across GLGs was less than that among individuals, and median bulk δ 15 N values differed by up to 5‰ among individuals. Significant correlation between bulk δ 15 N values and baseline (source AA) δ 15 N values indicates much of the observed isotopic variation among individuals reflects foraging within isotopically distinct food webs, rather than diet differences. This interpretation is supported by consistent differences in bulk δ 13 C values between the two individuals with lowest source AA δ 15 N values and the remaining whales. After accounting for baseline isotopic variation, comparable δ 15 N values among individuals indicates similar trophic-level diet, although uncertainties in relative trophic 15 N enrichment of individual AAs currently limits trophic position estimates for top consumers. Further research is required to clarify seasonal movement patterns and possible diet shifts of ECA/NWA killer whales to better define their role in marine ecosystems across the region. Article in Journal/Newspaper Arctic Beluga Beluga* narwhal* Newfoundland North West Atlantic Cambridge University Press Arctic Newfoundland Journal of the Marine Biological Association of the United Kingdom 94 6 1343 1355 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Killer whales in the Eastern Canadian Arctic (ECA) prey on narwhal, beluga, bowhead whales and seals, while further south in the north-west Atlantic (NWA), killer whales off the coast of Newfoundland and Labrador prey on both marine mammals and fish. Bulk and amino acid (AA) specific isotopic composition of dentinal collagen in teeth of 13 ECA/NWA killer whales were analysed to assess the degree, if any, of dietary specialization of killer whales across the region. Dentine was sampled from within annual growth layer groups (GLGs) to construct chronological profiles of stable nitrogen (δ 15 N) and carbon (δ 13 C) isotopic compositions for individual whales spanning 3–25 years. Interannual isotopic variation across GLGs was less than that among individuals, and median bulk δ 15 N values differed by up to 5‰ among individuals. Significant correlation between bulk δ 15 N values and baseline (source AA) δ 15 N values indicates much of the observed isotopic variation among individuals reflects foraging within isotopically distinct food webs, rather than diet differences. This interpretation is supported by consistent differences in bulk δ 13 C values between the two individuals with lowest source AA δ 15 N values and the remaining whales. After accounting for baseline isotopic variation, comparable δ 15 N values among individuals indicates similar trophic-level diet, although uncertainties in relative trophic 15 N enrichment of individual AAs currently limits trophic position estimates for top consumers. Further research is required to clarify seasonal movement patterns and possible diet shifts of ECA/NWA killer whales to better define their role in marine ecosystems across the region. |
format |
Article in Journal/Newspaper |
author |
Matthews, Cory J.D. Ferguson, Steven H. |
spellingShingle |
Matthews, Cory J.D. Ferguson, Steven H. Spatial segregation and similar trophic-level diet among eastern Canadian Arctic/north-west Atlantic killer whales inferred from bulk and compound specific isotopic analysis |
author_facet |
Matthews, Cory J.D. Ferguson, Steven H. |
author_sort |
Matthews, Cory J.D. |
title |
Spatial segregation and similar trophic-level diet among eastern Canadian Arctic/north-west Atlantic killer whales inferred from bulk and compound specific isotopic analysis |
title_short |
Spatial segregation and similar trophic-level diet among eastern Canadian Arctic/north-west Atlantic killer whales inferred from bulk and compound specific isotopic analysis |
title_full |
Spatial segregation and similar trophic-level diet among eastern Canadian Arctic/north-west Atlantic killer whales inferred from bulk and compound specific isotopic analysis |
title_fullStr |
Spatial segregation and similar trophic-level diet among eastern Canadian Arctic/north-west Atlantic killer whales inferred from bulk and compound specific isotopic analysis |
title_full_unstemmed |
Spatial segregation and similar trophic-level diet among eastern Canadian Arctic/north-west Atlantic killer whales inferred from bulk and compound specific isotopic analysis |
title_sort |
spatial segregation and similar trophic-level diet among eastern canadian arctic/north-west atlantic killer whales inferred from bulk and compound specific isotopic analysis |
publisher |
Cambridge University Press (CUP) |
publishDate |
2013 |
url |
http://dx.doi.org/10.1017/s0025315413001379 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315413001379 |
geographic |
Arctic Newfoundland |
geographic_facet |
Arctic Newfoundland |
genre |
Arctic Beluga Beluga* narwhal* Newfoundland North West Atlantic |
genre_facet |
Arctic Beluga Beluga* narwhal* Newfoundland North West Atlantic |
op_source |
Journal of the Marine Biological Association of the United Kingdom volume 94, issue 6, page 1343-1355 ISSN 0025-3154 1469-7769 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0025315413001379 |
container_title |
Journal of the Marine Biological Association of the United Kingdom |
container_volume |
94 |
container_issue |
6 |
container_start_page |
1343 |
op_container_end_page |
1355 |
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1813445865096871936 |