Antarctic fur seals foraging in the Polar Frontal Zone: inter-annual shifts in diet as shown from fecal and fatty acid analyses
International audience We studied the dietary preferences of Antarctic fur seals Arctocephalus gazella from Cap Noir, Îles Kerguelen, foraging in the Antarctic Polar Frontal Zone (PFZ) in February of 1998, 1999 and 2000. Scats were collected and analyzed for remaining prey hard parts in each of the...
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ftunivnantes:oai:HAL:hal-00192084v1 2023-05-15T13:37:48+02:00 Antarctic fur seals foraging in the Polar Frontal Zone: inter-annual shifts in diet as shown from fecal and fatty acid analyses Lea, Marie-Anne Cherel, Yves Guinet, Christophe Nichols, Peter D. Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Antartic Wildlife Research Unit School of Zoology, University of Tasmania Commonwealth Scientific & Industrial Research Organisation (CSIRO) Marine Research Antarctic Commonwealth Research Centre University of Tasmania Hobart, Australia (UTAS) 2002 https://hal.science/hal-00192084 en eng HAL CCSD Inter Research hal-00192084 https://hal.science/hal-00192084 ISSN: 0171-8630 EISSN: 1616-1599 Marine Ecology Progress Series https://hal.science/hal-00192084 Marine Ecology Progress Series, 2002, 245, pp.281-297 Myctophid Fatty acid Kerguelen Lipids Fish Squid Arctocephalus gazella [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.ES]Environmental Sciences/Environmental and Society [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2002 ftunivnantes 2023-02-08T08:15:25Z International audience We studied the dietary preferences of Antarctic fur seals Arctocephalus gazella from Cap Noir, Îles Kerguelen, foraging in the Antarctic Polar Frontal Zone (PFZ) in February of 1998, 1999 and 2000. Scats were collected and analyzed for remaining prey hard parts in each of the 3 years, and in 1999 and 2000, the fatty acid (FA) composition of fur seal milk samples was also examined for longerterm dietary preferences. Scat analyses revealed that seals foraged primarily on fish and some squid in all 3 years with 25 species of fish being taken during the study. Myctophid fish accounted for an average of 94% by number of all fish consumed with 3 species, Gymnoscopelus nicholsi, G. piabilis and Electrona subaspera, forming the core diet. Inter-annual differences in dietary species composition were apparent, however, with the presence of the mackerel icefish Champsocephalus gunnari in 1998 and the myctophid Protomyctophum tenisoni in 1999 accounting primarily for the differences observed between years. While reconstituted prey biomass per scat was similar between years, scats from 1998 represented less energy per gram than those from 1999 and 2000. This study highlights the usefulness of using FA signature analysis to confirm longer-term shifts in dietary intake of fur seals using milk samples. Polyunsaturated fatty acids (PUFAs) were significantly more prevalent in the 1999 milk samples, which were also lower in overall lipid content (43% vs 53%). G. nicholsi, a particularly oily fish, occurred in higher proportions in the diet in 2000, perhaps explaining the higher incidence of monounsaturated fatty acids (MUFAs) in this year and the generally higher lipid levels present in milk samples. The inter-annual variation in the diet of Antarctic fur seals confirmed by these 2 techniques lends support to the hypothesis that previously identified variations in oceanographic conditions surrounding Îles Kerguelen in 1998, 1999 and 2000 affect the availability of fur seal prey resources. Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seals Arctocephalus gazella Icefish Université de Nantes: HAL-UNIV-NANTES Antarctic The Antarctic Kerguelen Îles Kerguelen ENVELOPE(69.167,69.167,-49.250,-49.250) Cap Noir ENVELOPE(70.452,70.452,-49.069,-49.069) |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
Myctophid Fatty acid Kerguelen Lipids Fish Squid Arctocephalus gazella [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.ES]Environmental Sciences/Environmental and Society [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
Myctophid Fatty acid Kerguelen Lipids Fish Squid Arctocephalus gazella [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.ES]Environmental Sciences/Environmental and Society [SDE.MCG]Environmental Sciences/Global Changes Lea, Marie-Anne Cherel, Yves Guinet, Christophe Nichols, Peter D. Antarctic fur seals foraging in the Polar Frontal Zone: inter-annual shifts in diet as shown from fecal and fatty acid analyses |
topic_facet |
Myctophid Fatty acid Kerguelen Lipids Fish Squid Arctocephalus gazella [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.ES]Environmental Sciences/Environmental and Society [SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience We studied the dietary preferences of Antarctic fur seals Arctocephalus gazella from Cap Noir, Îles Kerguelen, foraging in the Antarctic Polar Frontal Zone (PFZ) in February of 1998, 1999 and 2000. Scats were collected and analyzed for remaining prey hard parts in each of the 3 years, and in 1999 and 2000, the fatty acid (FA) composition of fur seal milk samples was also examined for longerterm dietary preferences. Scat analyses revealed that seals foraged primarily on fish and some squid in all 3 years with 25 species of fish being taken during the study. Myctophid fish accounted for an average of 94% by number of all fish consumed with 3 species, Gymnoscopelus nicholsi, G. piabilis and Electrona subaspera, forming the core diet. Inter-annual differences in dietary species composition were apparent, however, with the presence of the mackerel icefish Champsocephalus gunnari in 1998 and the myctophid Protomyctophum tenisoni in 1999 accounting primarily for the differences observed between years. While reconstituted prey biomass per scat was similar between years, scats from 1998 represented less energy per gram than those from 1999 and 2000. This study highlights the usefulness of using FA signature analysis to confirm longer-term shifts in dietary intake of fur seals using milk samples. Polyunsaturated fatty acids (PUFAs) were significantly more prevalent in the 1999 milk samples, which were also lower in overall lipid content (43% vs 53%). G. nicholsi, a particularly oily fish, occurred in higher proportions in the diet in 2000, perhaps explaining the higher incidence of monounsaturated fatty acids (MUFAs) in this year and the generally higher lipid levels present in milk samples. The inter-annual variation in the diet of Antarctic fur seals confirmed by these 2 techniques lends support to the hypothesis that previously identified variations in oceanographic conditions surrounding Îles Kerguelen in 1998, 1999 and 2000 affect the availability of fur seal prey resources. |
author2 |
Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Antartic Wildlife Research Unit School of Zoology, University of Tasmania Commonwealth Scientific & Industrial Research Organisation (CSIRO) Marine Research Antarctic Commonwealth Research Centre University of Tasmania Hobart, Australia (UTAS) |
format |
Article in Journal/Newspaper |
author |
Lea, Marie-Anne Cherel, Yves Guinet, Christophe Nichols, Peter D. |
author_facet |
Lea, Marie-Anne Cherel, Yves Guinet, Christophe Nichols, Peter D. |
author_sort |
Lea, Marie-Anne |
title |
Antarctic fur seals foraging in the Polar Frontal Zone: inter-annual shifts in diet as shown from fecal and fatty acid analyses |
title_short |
Antarctic fur seals foraging in the Polar Frontal Zone: inter-annual shifts in diet as shown from fecal and fatty acid analyses |
title_full |
Antarctic fur seals foraging in the Polar Frontal Zone: inter-annual shifts in diet as shown from fecal and fatty acid analyses |
title_fullStr |
Antarctic fur seals foraging in the Polar Frontal Zone: inter-annual shifts in diet as shown from fecal and fatty acid analyses |
title_full_unstemmed |
Antarctic fur seals foraging in the Polar Frontal Zone: inter-annual shifts in diet as shown from fecal and fatty acid analyses |
title_sort |
antarctic fur seals foraging in the polar frontal zone: inter-annual shifts in diet as shown from fecal and fatty acid analyses |
publisher |
HAL CCSD |
publishDate |
2002 |
url |
https://hal.science/hal-00192084 |
long_lat |
ENVELOPE(69.167,69.167,-49.250,-49.250) ENVELOPE(70.452,70.452,-49.069,-49.069) |
geographic |
Antarctic The Antarctic Kerguelen Îles Kerguelen Cap Noir |
geographic_facet |
Antarctic The Antarctic Kerguelen Îles Kerguelen Cap Noir |
genre |
Antarc* Antarctic Antarctic Fur Seals Arctocephalus gazella Icefish |
genre_facet |
Antarc* Antarctic Antarctic Fur Seals Arctocephalus gazella Icefish |
op_source |
ISSN: 0171-8630 EISSN: 1616-1599 Marine Ecology Progress Series https://hal.science/hal-00192084 Marine Ecology Progress Series, 2002, 245, pp.281-297 |
op_relation |
hal-00192084 https://hal.science/hal-00192084 |
_version_ |
1766097827145973760 |