Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals
International audience Indirect ecological interactions such as competition for resources between fisheries and marine predators have often been proposed but can be difficult to demonstrate empirically. The Kerguelen Plateau in the Southern Indian Ocean supports fisheries for both Patagonian toothfi...
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Online Access: | https://hal.science/hal-03903497 https://doi.org/10.3389/fmars.2022.1006120 |
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ftunivrochelle:oai:HAL:hal-03903497v1 2024-02-11T10:03:29+01:00 Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals Hindell, Mark Andrew Mcmahon, Clive Reginald Guinet, Christophe Harcourt, Rob Jonsen, Ian David Raymond, Ben Maschette, Dale Institute of Marine and Antarctic Studies University of Tasmania Hobart, Australia (UTAS) Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) School of Natural Sciences Australia Macquarie University 2022-11-18 https://hal.science/hal-03903497 https://doi.org/10.3389/fmars.2022.1006120 en eng HAL CCSD Frontiers Media info:eu-repo/semantics/altIdentifier/doi/10.3389/fmars.2022.1006120 hal-03903497 https://hal.science/hal-03903497 doi:10.3389/fmars.2022.1006120 WOS: 000912242800001 ISSN: 2296-7745 Frontiers in Marine Science https://hal.science/hal-03903497 Frontiers in Marine Science, 2022, 9, pp.1006120. ⟨10.3389/fmars.2022.1006120⟩ Patagonian toothfish mackerel icefish Kerguelen Plateau southern elephant seal fisheries interactions [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2022 ftunivrochelle https://doi.org/10.3389/fmars.2022.1006120 2024-01-23T23:34:18Z International audience Indirect ecological interactions such as competition for resources between fisheries and marine predators have often been proposed but can be difficult to demonstrate empirically. The Kerguelen Plateau in the Southern Indian Ocean supports fisheries for both Patagonian toothfish and mackerel icefish and is also an important foraging ground for several avian and mammalian predators, including the southern elephant seal. We quantified the spatio-temporal use of the plateau by southern elephant seals and found that males and females spent 30% of their time on the plateau within the commonly used fishing grounds, indicating the possibility of competition for resources there. We then contrasted the seals’ use of two habitat types, the benthos (where interactions with the long-line fisheries are most likely) and the epi-pelagic zone. The likelihood of feeding on the benthos declined as ocean depth increased and was also less likely at night. Males were also more likely to feed on the benthos than females. The sub-adult male seals consumed an estimated 6,814 – 14,848 tons of high energy content prey (including toothfish) and females 7,085 – 18,037 tons from the plateau during the post-molt winter months. For males this represented 79.6 - 173.4% of the mean annual catch by the Kerguelen fishery compared to 82.8 - 210.7% for adult females. When considering the seals consumption of fish from the benthos within the fishing grounds these estimates decreased to 3.6 - 15.1% of the fishery’s total annual catch for females and 7.8 - 19.1% for males. While this further indicates the possibility of indirect ecological interactions (with the fishery taking more fish than the seals), the lack of detailed diet information for the seals precludes us from establishing the degree or nature of the possible interactions because the importance of toothfish and icefish in the diet of the seals is unknown. However, the unique life history and highly polygynous nature of this species, and the lack of evidence of a ... Article in Journal/Newspaper Elephant Seal Elephant Seals Icefish Patagonian Toothfish Southern Elephant Seal Southern Elephant Seals HAL - Université de La Rochelle Indian Kerguelen Frontiers in Marine Science 9 |
institution |
Open Polar |
collection |
HAL - Université de La Rochelle |
op_collection_id |
ftunivrochelle |
language |
English |
topic |
Patagonian toothfish mackerel icefish Kerguelen Plateau southern elephant seal fisheries interactions [SDE]Environmental Sciences |
spellingShingle |
Patagonian toothfish mackerel icefish Kerguelen Plateau southern elephant seal fisheries interactions [SDE]Environmental Sciences Hindell, Mark Andrew Mcmahon, Clive Reginald Guinet, Christophe Harcourt, Rob Jonsen, Ian David Raymond, Ben Maschette, Dale Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals |
topic_facet |
Patagonian toothfish mackerel icefish Kerguelen Plateau southern elephant seal fisheries interactions [SDE]Environmental Sciences |
description |
International audience Indirect ecological interactions such as competition for resources between fisheries and marine predators have often been proposed but can be difficult to demonstrate empirically. The Kerguelen Plateau in the Southern Indian Ocean supports fisheries for both Patagonian toothfish and mackerel icefish and is also an important foraging ground for several avian and mammalian predators, including the southern elephant seal. We quantified the spatio-temporal use of the plateau by southern elephant seals and found that males and females spent 30% of their time on the plateau within the commonly used fishing grounds, indicating the possibility of competition for resources there. We then contrasted the seals’ use of two habitat types, the benthos (where interactions with the long-line fisheries are most likely) and the epi-pelagic zone. The likelihood of feeding on the benthos declined as ocean depth increased and was also less likely at night. Males were also more likely to feed on the benthos than females. The sub-adult male seals consumed an estimated 6,814 – 14,848 tons of high energy content prey (including toothfish) and females 7,085 – 18,037 tons from the plateau during the post-molt winter months. For males this represented 79.6 - 173.4% of the mean annual catch by the Kerguelen fishery compared to 82.8 - 210.7% for adult females. When considering the seals consumption of fish from the benthos within the fishing grounds these estimates decreased to 3.6 - 15.1% of the fishery’s total annual catch for females and 7.8 - 19.1% for males. While this further indicates the possibility of indirect ecological interactions (with the fishery taking more fish than the seals), the lack of detailed diet information for the seals precludes us from establishing the degree or nature of the possible interactions because the importance of toothfish and icefish in the diet of the seals is unknown. However, the unique life history and highly polygynous nature of this species, and the lack of evidence of a ... |
author2 |
Institute of Marine and Antarctic Studies University of Tasmania Hobart, Australia (UTAS) Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) School of Natural Sciences Australia Macquarie University |
format |
Article in Journal/Newspaper |
author |
Hindell, Mark Andrew Mcmahon, Clive Reginald Guinet, Christophe Harcourt, Rob Jonsen, Ian David Raymond, Ben Maschette, Dale |
author_facet |
Hindell, Mark Andrew Mcmahon, Clive Reginald Guinet, Christophe Harcourt, Rob Jonsen, Ian David Raymond, Ben Maschette, Dale |
author_sort |
Hindell, Mark Andrew |
title |
Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals |
title_short |
Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals |
title_full |
Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals |
title_fullStr |
Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals |
title_full_unstemmed |
Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals |
title_sort |
assessing the potential for resource competition between the kerguelen plateau fisheries and southern elephant seals |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://hal.science/hal-03903497 https://doi.org/10.3389/fmars.2022.1006120 |
geographic |
Indian Kerguelen |
geographic_facet |
Indian Kerguelen |
genre |
Elephant Seal Elephant Seals Icefish Patagonian Toothfish Southern Elephant Seal Southern Elephant Seals |
genre_facet |
Elephant Seal Elephant Seals Icefish Patagonian Toothfish Southern Elephant Seal Southern Elephant Seals |
op_source |
ISSN: 2296-7745 Frontiers in Marine Science https://hal.science/hal-03903497 Frontiers in Marine Science, 2022, 9, pp.1006120. ⟨10.3389/fmars.2022.1006120⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3389/fmars.2022.1006120 hal-03903497 https://hal.science/hal-03903497 doi:10.3389/fmars.2022.1006120 WOS: 000912242800001 |
op_doi |
https://doi.org/10.3389/fmars.2022.1006120 |
container_title |
Frontiers in Marine Science |
container_volume |
9 |
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1790599745679392768 |