Stable isotopes reveal the trophic position and mesopelagic fish diet of female southern elephant seals breeding on the Kerguelen Islands
International audience Trophic interactions between organisms are the main drivers of ecosystem dynamics, but scant dietary information is available for wide-ranging predators during migration. We investigated feeding habits of a key consumer of the Southern Ocean, the southern elephant seal Miroung...
Published in: | Marine Ecology Progress Series |
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Format: | Article in Journal/Newspaper |
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Online Access: | https://doi.org/10.3354/meps07673 https://hal.archives-ouvertes.fr/hal-00338488 |
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fttriple:oai:gotriple.eu:10670/1.0h5776 2023-05-15T15:55:51+02:00 Stable isotopes reveal the trophic position and mesopelagic fish diet of female southern elephant seals breeding on the Kerguelen Islands Cherel, Yves Ducatez, Simon Fontaine, C. Richard, Pierre Guinet, Christophe Centre d'études biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Centre de Recherche sur les Ecosystèmes Littoraux Anthropisés (CRELA) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS) 2008-10-28 https://doi.org/10.3354/meps07673 https://hal.archives-ouvertes.fr/hal-00338488 en eng HAL CCSD Inter Research hal-00338488 doi:10.3354/meps07673 10670/1.0h5776 https://hal.archives-ouvertes.fr/hal-00338488 undefined Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0171-8630 EISSN: 1616-1599 Marine Ecology Progress Series Marine Ecology Progress Series, Inter Research, 2008, 370, pp.239-247. ⟨10.3354/meps07673⟩ Cephalopod · Mesopelagic fish · Myctophid · Pelagic ecosystem · Southern Ocean · Squid envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2008 fttriple https://doi.org/10.3354/meps07673 2023-01-22T17:01:32Z International audience Trophic interactions between organisms are the main drivers of ecosystem dynamics, but scant dietary information is available for wide-ranging predators during migration. We investigated feeding habits of a key consumer of the Southern Ocean, the southern elephant seal Miroungia leonina, by comparing its blood δ13C and δ15N values with those of various marine organisms, including crustaceans, squid, fishes, seabirds and fur seals. At the end of winter, δ13C values (–23.1 to –20.1‰) indicate that female elephant seals forage mainly in the vicinity of the Polar Front and in the Polar Frontal Zone. Trophic levels derived from δ15N values (trophic level = 4.6) show that the southern elephant seal is a top consumer in the pelagic ecosystem that is dominated by colossal squid. The mean δ15N value of seals (10.1 ± 0.3‰) indicates that they are not crustacean eaters, but instead feed on crustacean-eating prey. Surprisingly, most of the previously identified prey species have isotope δ13C and δ15N values that do not fit with those of potential food items. The most singular pattern to emerge from δ15N values of predators and prey is that female seals are likely to feed on myctophid fishes, not squid or Patagonian toothfish. We therefore suggest that they occupy a unique trophic niche amongst the guild of air-breathing, diving vertebrates by feeding on mesopelagic fish at great depths. In turn, this finding emphasizes the role of myctophids in oceanic waters and will help to quantify and model fluxes of matter and energy within the pelagic ecosystem of the Southern Ocean. Article in Journal/Newspaper Colossal Squid Elephant Seal Elephant Seals Kerguelen Islands Patagonian Toothfish Southern Elephant Seal Southern Elephant Seals Southern Ocean Unknown Kerguelen Kerguelen Islands Southern Ocean Marine Ecology Progress Series 370 239 247 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
Cephalopod · Mesopelagic fish · Myctophid · Pelagic ecosystem · Southern Ocean · Squid envir geo |
spellingShingle |
Cephalopod · Mesopelagic fish · Myctophid · Pelagic ecosystem · Southern Ocean · Squid envir geo Cherel, Yves Ducatez, Simon Fontaine, C. Richard, Pierre Guinet, Christophe Stable isotopes reveal the trophic position and mesopelagic fish diet of female southern elephant seals breeding on the Kerguelen Islands |
topic_facet |
Cephalopod · Mesopelagic fish · Myctophid · Pelagic ecosystem · Southern Ocean · Squid envir geo |
description |
International audience Trophic interactions between organisms are the main drivers of ecosystem dynamics, but scant dietary information is available for wide-ranging predators during migration. We investigated feeding habits of a key consumer of the Southern Ocean, the southern elephant seal Miroungia leonina, by comparing its blood δ13C and δ15N values with those of various marine organisms, including crustaceans, squid, fishes, seabirds and fur seals. At the end of winter, δ13C values (–23.1 to –20.1‰) indicate that female elephant seals forage mainly in the vicinity of the Polar Front and in the Polar Frontal Zone. Trophic levels derived from δ15N values (trophic level = 4.6) show that the southern elephant seal is a top consumer in the pelagic ecosystem that is dominated by colossal squid. The mean δ15N value of seals (10.1 ± 0.3‰) indicates that they are not crustacean eaters, but instead feed on crustacean-eating prey. Surprisingly, most of the previously identified prey species have isotope δ13C and δ15N values that do not fit with those of potential food items. The most singular pattern to emerge from δ15N values of predators and prey is that female seals are likely to feed on myctophid fishes, not squid or Patagonian toothfish. We therefore suggest that they occupy a unique trophic niche amongst the guild of air-breathing, diving vertebrates by feeding on mesopelagic fish at great depths. In turn, this finding emphasizes the role of myctophids in oceanic waters and will help to quantify and model fluxes of matter and energy within the pelagic ecosystem of the Southern Ocean. |
author2 |
Centre d'études biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Centre de Recherche sur les Ecosystèmes Littoraux Anthropisés (CRELA) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Cherel, Yves Ducatez, Simon Fontaine, C. Richard, Pierre Guinet, Christophe |
author_facet |
Cherel, Yves Ducatez, Simon Fontaine, C. Richard, Pierre Guinet, Christophe |
author_sort |
Cherel, Yves |
title |
Stable isotopes reveal the trophic position and mesopelagic fish diet of female southern elephant seals breeding on the Kerguelen Islands |
title_short |
Stable isotopes reveal the trophic position and mesopelagic fish diet of female southern elephant seals breeding on the Kerguelen Islands |
title_full |
Stable isotopes reveal the trophic position and mesopelagic fish diet of female southern elephant seals breeding on the Kerguelen Islands |
title_fullStr |
Stable isotopes reveal the trophic position and mesopelagic fish diet of female southern elephant seals breeding on the Kerguelen Islands |
title_full_unstemmed |
Stable isotopes reveal the trophic position and mesopelagic fish diet of female southern elephant seals breeding on the Kerguelen Islands |
title_sort |
stable isotopes reveal the trophic position and mesopelagic fish diet of female southern elephant seals breeding on the kerguelen islands |
publisher |
HAL CCSD |
publishDate |
2008 |
url |
https://doi.org/10.3354/meps07673 https://hal.archives-ouvertes.fr/hal-00338488 |
geographic |
Kerguelen Kerguelen Islands Southern Ocean |
geographic_facet |
Kerguelen Kerguelen Islands Southern Ocean |
genre |
Colossal Squid Elephant Seal Elephant Seals Kerguelen Islands Patagonian Toothfish Southern Elephant Seal Southern Elephant Seals Southern Ocean |
genre_facet |
Colossal Squid Elephant Seal Elephant Seals Kerguelen Islands Patagonian Toothfish Southern Elephant Seal Southern Elephant Seals Southern Ocean |
op_source |
Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0171-8630 EISSN: 1616-1599 Marine Ecology Progress Series Marine Ecology Progress Series, Inter Research, 2008, 370, pp.239-247. ⟨10.3354/meps07673⟩ |
op_relation |
hal-00338488 doi:10.3354/meps07673 10670/1.0h5776 https://hal.archives-ouvertes.fr/hal-00338488 |
op_rights |
undefined |
op_doi |
https://doi.org/10.3354/meps07673 |
container_title |
Marine Ecology Progress Series |
container_volume |
370 |
container_start_page |
239 |
op_container_end_page |
247 |
_version_ |
1766391336289697792 |