Fifty years of Cook Inlet beluga whale feeding ecology from isotopes in bone and teeth
Beluga whales Delphinapterus leucas that reside in Cook Inlet (CIBW) are important to coastal Alaska Native culture and subsistence, tourism, and ecologically as a top-level predator. Due to a ~50% population decline in the 1990s, the distinct population segment in Cook Inlet was designated depleted...
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ftdoajarticles:oai:doaj.org/article:ab13aadb7cff4c0781b7f1521e8dd75d 2023-05-15T15:41:43+02:00 Fifty years of Cook Inlet beluga whale feeding ecology from isotopes in bone and teeth Nelson, MA Quakenbush, LT Mahoney, BA Taras, BD Wooller, MJ 2018-06-01T00:00:00Z https://doi.org/10.3354/esr00890 https://doaj.org/article/ab13aadb7cff4c0781b7f1521e8dd75d EN eng Inter-Research https://www.int-res.com/abstracts/esr/v36/p77-87/ https://doaj.org/toc/1863-5407 https://doaj.org/toc/1613-4796 1863-5407 1613-4796 doi:10.3354/esr00890 https://doaj.org/article/ab13aadb7cff4c0781b7f1521e8dd75d Endangered Species Research, Vol 36, Pp 77-87 (2018) Zoology QL1-991 Botany QK1-989 article 2018 ftdoajarticles https://doi.org/10.3354/esr00890 2022-12-31T11:30:35Z Beluga whales Delphinapterus leucas that reside in Cook Inlet (CIBW) are important to coastal Alaska Native culture and subsistence, tourism, and ecologically as a top-level predator. Due to a ~50% population decline in the 1990s, the distinct population segment in Cook Inlet was designated depleted under the Marine Mammal Protection Act in 2000 and listed as endangered under the Endangered Species Act in 2008. Diet changes are a concern in CIBW lack of recovery, but beluga feeding ecology is difficult to study. Skulls from 20 CIBW and tooth growth layer groups (GLGs) from 26 individual CIBW showed decreasing trends for both nitrogen and carbon stable isotope ratios (expressed as δ15N and δ13C values) from 1962 to 2007. The decline in δ15N values (~1 to 2‰) could indicate a trophic level shift, but the magnitude of decline in δ13C values (~3‰) is much greater (>5 times greater) than expected for a trophic level shift. A shifted baseline or increased use of freshwater prey could explain the decline in δ13C values. We compared the strontium isotope composition (87Sr/86Sr ratios) of GLGs with rivers that flow into Cook Inlet and used δ15N values from the essential amino acid phenylalanine to determine that declining δ13C values may be explained by 2 scenarios: (1) CIBW foraged in the same location while the environmental isotopic baseline changed, or (2) CIBW foraged in a different location with a different baseline. This study presents the first evidence for a long-term (~50 yr) change in CIBW feeding ecology. Article in Journal/Newspaper Beluga Beluga whale Beluga* Delphinapterus leucas Alaska Directory of Open Access Journals: DOAJ Articles Endangered Species Research 36 77 87 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Zoology QL1-991 Botany QK1-989 |
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Zoology QL1-991 Botany QK1-989 Nelson, MA Quakenbush, LT Mahoney, BA Taras, BD Wooller, MJ Fifty years of Cook Inlet beluga whale feeding ecology from isotopes in bone and teeth |
topic_facet |
Zoology QL1-991 Botany QK1-989 |
description |
Beluga whales Delphinapterus leucas that reside in Cook Inlet (CIBW) are important to coastal Alaska Native culture and subsistence, tourism, and ecologically as a top-level predator. Due to a ~50% population decline in the 1990s, the distinct population segment in Cook Inlet was designated depleted under the Marine Mammal Protection Act in 2000 and listed as endangered under the Endangered Species Act in 2008. Diet changes are a concern in CIBW lack of recovery, but beluga feeding ecology is difficult to study. Skulls from 20 CIBW and tooth growth layer groups (GLGs) from 26 individual CIBW showed decreasing trends for both nitrogen and carbon stable isotope ratios (expressed as δ15N and δ13C values) from 1962 to 2007. The decline in δ15N values (~1 to 2‰) could indicate a trophic level shift, but the magnitude of decline in δ13C values (~3‰) is much greater (>5 times greater) than expected for a trophic level shift. A shifted baseline or increased use of freshwater prey could explain the decline in δ13C values. We compared the strontium isotope composition (87Sr/86Sr ratios) of GLGs with rivers that flow into Cook Inlet and used δ15N values from the essential amino acid phenylalanine to determine that declining δ13C values may be explained by 2 scenarios: (1) CIBW foraged in the same location while the environmental isotopic baseline changed, or (2) CIBW foraged in a different location with a different baseline. This study presents the first evidence for a long-term (~50 yr) change in CIBW feeding ecology. |
format |
Article in Journal/Newspaper |
author |
Nelson, MA Quakenbush, LT Mahoney, BA Taras, BD Wooller, MJ |
author_facet |
Nelson, MA Quakenbush, LT Mahoney, BA Taras, BD Wooller, MJ |
author_sort |
Nelson, MA |
title |
Fifty years of Cook Inlet beluga whale feeding ecology from isotopes in bone and teeth |
title_short |
Fifty years of Cook Inlet beluga whale feeding ecology from isotopes in bone and teeth |
title_full |
Fifty years of Cook Inlet beluga whale feeding ecology from isotopes in bone and teeth |
title_fullStr |
Fifty years of Cook Inlet beluga whale feeding ecology from isotopes in bone and teeth |
title_full_unstemmed |
Fifty years of Cook Inlet beluga whale feeding ecology from isotopes in bone and teeth |
title_sort |
fifty years of cook inlet beluga whale feeding ecology from isotopes in bone and teeth |
publisher |
Inter-Research |
publishDate |
2018 |
url |
https://doi.org/10.3354/esr00890 https://doaj.org/article/ab13aadb7cff4c0781b7f1521e8dd75d |
genre |
Beluga Beluga whale Beluga* Delphinapterus leucas Alaska |
genre_facet |
Beluga Beluga whale Beluga* Delphinapterus leucas Alaska |
op_source |
Endangered Species Research, Vol 36, Pp 77-87 (2018) |
op_relation |
https://www.int-res.com/abstracts/esr/v36/p77-87/ https://doaj.org/toc/1863-5407 https://doaj.org/toc/1613-4796 1863-5407 1613-4796 doi:10.3354/esr00890 https://doaj.org/article/ab13aadb7cff4c0781b7f1521e8dd75d |
op_doi |
https://doi.org/10.3354/esr00890 |
container_title |
Endangered Species Research |
container_volume |
36 |
container_start_page |
77 |
op_container_end_page |
87 |
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1766374612391690240 |