Geographical variation in carbon stable isotope signatures of marine predators: a tool to investigate their foraging areas in the Southern Ocean
International audience Stable carbon isotope signatures (δ13C) are increasingly being used to determine the foraging habitats of consumers in the Southern Ocean. An underlying assumption is that a latitudinal gradient in δ13C values at the base of the food chain should also be reflected in organisms...
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ftunivnantes:oai:HAL:hal-00182469v1 2023-05-15T13:49:49+02:00 Geographical variation in carbon stable isotope signatures of marine predators: a tool to investigate their foraging areas in the Southern Ocean Cherel, Yves Hobson, Keith A. Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Environment and Climate Change Canada 2007-01 https://hal.science/hal-00182469 en eng HAL CCSD Inter Research hal-00182469 https://hal.science/hal-00182469 ISSN: 0171-8630 EISSN: 1616-1599 Marine Ecology Progress Series https://hal.science/hal-00182469 Marine Ecology Progress Series, 2007, 329, pp.281-287 Antarctica Latitude Marine foodweb Carbon-13 Nitrogen-15 Penguin Seabird [SDE.BE]Environmental Sciences/Biodiversity and Ecology info:eu-repo/semantics/article Journal articles 2007 ftunivnantes 2023-02-08T08:32:46Z International audience Stable carbon isotope signatures (δ13C) are increasingly being used to determine the foraging habitats of consumers in the Southern Ocean. An underlying assumption is that a latitudinal gradient in δ13C values at the base of the food chain should also be reflected in organisms at higher trophic levels. Our main objective was to test that assumption by using penguin chicks (7 taxa) as predator models, because the feeding habits of provisioning adult penguins are well known during the chick-rearing period. As expected, a strong negative correlation was found between latitude and δ13C values of whole blood of penguin chicks. δ13C values ranged from –24.8 ± 0.5‰ in Adélie penguins living in Antarctica (67°S), to –19.5 ± 0.3‰ in northern rockhopper penguins living in the subtropics (38°S). Unlike δ13C values, stable nitrogen isotope signatures (δ15N) were not related to latitude but instead were strongly affected by penguins' diet, with fish-eaters having higher δ15N values than crustacean eaters. δ13C values also reflect more local spatial foraging segregation of penguins at a subantarctic archipelago (Kerguelen Islands), where they varied from –22.3 ± 0.2‰ for king penguins feeding in oceanic waters to –15.9 ± 0.3‰ for gentoo penguins foraging in an enclosed bay. Blood δ13C values moreover allowed differentiation of 2 sub-populations of gentoo penguins foraging in 2 different environments at Kerguelen. The method has 2 limitations related to the lack of longitudinal variations and to overlapping δ13C values due to different isotopic gradients (latitudinal and inshore/offshore) in the marine environment. The study nevertheless shows that the δ13C values of marine predators are efficient indicators of the foraging habitats at various spatial scales, both in terms of latitude in oceanic waters, and in terms of inshore/offshore gradients in waters surrounding subantarctic islands. Article in Journal/Newspaper Antarc* Antarctica Kerguelen Islands King Penguins Southern Ocean Université de Nantes: HAL-UNIV-NANTES Southern Ocean Kerguelen Kerguelen Islands |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
Antarctica Latitude Marine foodweb Carbon-13 Nitrogen-15 Penguin Seabird [SDE.BE]Environmental Sciences/Biodiversity and Ecology |
spellingShingle |
Antarctica Latitude Marine foodweb Carbon-13 Nitrogen-15 Penguin Seabird [SDE.BE]Environmental Sciences/Biodiversity and Ecology Cherel, Yves Hobson, Keith A. Geographical variation in carbon stable isotope signatures of marine predators: a tool to investigate their foraging areas in the Southern Ocean |
topic_facet |
Antarctica Latitude Marine foodweb Carbon-13 Nitrogen-15 Penguin Seabird [SDE.BE]Environmental Sciences/Biodiversity and Ecology |
description |
International audience Stable carbon isotope signatures (δ13C) are increasingly being used to determine the foraging habitats of consumers in the Southern Ocean. An underlying assumption is that a latitudinal gradient in δ13C values at the base of the food chain should also be reflected in organisms at higher trophic levels. Our main objective was to test that assumption by using penguin chicks (7 taxa) as predator models, because the feeding habits of provisioning adult penguins are well known during the chick-rearing period. As expected, a strong negative correlation was found between latitude and δ13C values of whole blood of penguin chicks. δ13C values ranged from –24.8 ± 0.5‰ in Adélie penguins living in Antarctica (67°S), to –19.5 ± 0.3‰ in northern rockhopper penguins living in the subtropics (38°S). Unlike δ13C values, stable nitrogen isotope signatures (δ15N) were not related to latitude but instead were strongly affected by penguins' diet, with fish-eaters having higher δ15N values than crustacean eaters. δ13C values also reflect more local spatial foraging segregation of penguins at a subantarctic archipelago (Kerguelen Islands), where they varied from –22.3 ± 0.2‰ for king penguins feeding in oceanic waters to –15.9 ± 0.3‰ for gentoo penguins foraging in an enclosed bay. Blood δ13C values moreover allowed differentiation of 2 sub-populations of gentoo penguins foraging in 2 different environments at Kerguelen. The method has 2 limitations related to the lack of longitudinal variations and to overlapping δ13C values due to different isotopic gradients (latitudinal and inshore/offshore) in the marine environment. The study nevertheless shows that the δ13C values of marine predators are efficient indicators of the foraging habitats at various spatial scales, both in terms of latitude in oceanic waters, and in terms of inshore/offshore gradients in waters surrounding subantarctic islands. |
author2 |
Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Environment and Climate Change Canada |
format |
Article in Journal/Newspaper |
author |
Cherel, Yves Hobson, Keith A. |
author_facet |
Cherel, Yves Hobson, Keith A. |
author_sort |
Cherel, Yves |
title |
Geographical variation in carbon stable isotope signatures of marine predators: a tool to investigate their foraging areas in the Southern Ocean |
title_short |
Geographical variation in carbon stable isotope signatures of marine predators: a tool to investigate their foraging areas in the Southern Ocean |
title_full |
Geographical variation in carbon stable isotope signatures of marine predators: a tool to investigate their foraging areas in the Southern Ocean |
title_fullStr |
Geographical variation in carbon stable isotope signatures of marine predators: a tool to investigate their foraging areas in the Southern Ocean |
title_full_unstemmed |
Geographical variation in carbon stable isotope signatures of marine predators: a tool to investigate their foraging areas in the Southern Ocean |
title_sort |
geographical variation in carbon stable isotope signatures of marine predators: a tool to investigate their foraging areas in the southern ocean |
publisher |
HAL CCSD |
publishDate |
2007 |
url |
https://hal.science/hal-00182469 |
geographic |
Southern Ocean Kerguelen Kerguelen Islands |
geographic_facet |
Southern Ocean Kerguelen Kerguelen Islands |
genre |
Antarc* Antarctica Kerguelen Islands King Penguins Southern Ocean |
genre_facet |
Antarc* Antarctica Kerguelen Islands King Penguins Southern Ocean |
op_source |
ISSN: 0171-8630 EISSN: 1616-1599 Marine Ecology Progress Series https://hal.science/hal-00182469 Marine Ecology Progress Series, 2007, 329, pp.281-287 |
op_relation |
hal-00182469 https://hal.science/hal-00182469 |
_version_ |
1766252332704595968 |