Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals
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...
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Online Access: | https://doi.org/10.3389/fmars.2022.1006120 http://ecite.utas.edu.au/155019 |
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ftunivtasecite:oai:ecite.utas.edu.au:155019 2023-05-15T16:05:24+02:00 Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals Hindell, MA McMahon, CR Guinet, C Harcourt, R Jonsen, ID Raymond, B Maschette, D 2022 application/pdf https://doi.org/10.3389/fmars.2022.1006120 http://ecite.utas.edu.au/155019 en eng Frontiers Research Foundation http://ecite.utas.edu.au/155019/1/155019 - Assessing the potential for resource competition between the Kerguelen.pdf http://dx.doi.org/10.3389/fmars.2022.1006120 Hindell, MA and McMahon, CR and Guinet, C and Harcourt, R and Jonsen, ID and Raymond, B and Maschette, D, Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals, Frontiers in Marine Science, 9 Article 1006120. ISSN 2296-7745 (2022) [Refereed Article] http://ecite.utas.edu.au/155019 Agricultural Veterinary and Food Sciences Fisheries sciences Fisheries management Refereed Article PeerReviewed 2022 ftunivtasecite https://doi.org/10.3389/fmars.2022.1006120 2023-02-20T23:17:09Z 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 fisherys 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 measurable effect on either the ... Article in Journal/Newspaper Elephant Seal Elephant Seals Icefish Patagonian Toothfish Southern Elephant Seal Southern Elephant Seals eCite UTAS (University of Tasmania) Kerguelen Indian Frontiers in Marine Science 9 |
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Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Agricultural Veterinary and Food Sciences Fisheries sciences Fisheries management |
spellingShingle |
Agricultural Veterinary and Food Sciences Fisheries sciences Fisheries management Hindell, MA McMahon, CR Guinet, C Harcourt, R Jonsen, ID Raymond, B Maschette, D Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals |
topic_facet |
Agricultural Veterinary and Food Sciences Fisheries sciences Fisheries management |
description |
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 fisherys 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 measurable effect on either the ... |
format |
Article in Journal/Newspaper |
author |
Hindell, MA McMahon, CR Guinet, C Harcourt, R Jonsen, ID Raymond, B Maschette, D |
author_facet |
Hindell, MA McMahon, CR Guinet, C Harcourt, R Jonsen, ID Raymond, B Maschette, D |
author_sort |
Hindell, MA |
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 |
Frontiers Research Foundation |
publishDate |
2022 |
url |
https://doi.org/10.3389/fmars.2022.1006120 http://ecite.utas.edu.au/155019 |
geographic |
Kerguelen Indian |
geographic_facet |
Kerguelen Indian |
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_relation |
http://ecite.utas.edu.au/155019/1/155019 - Assessing the potential for resource competition between the Kerguelen.pdf http://dx.doi.org/10.3389/fmars.2022.1006120 Hindell, MA and McMahon, CR and Guinet, C and Harcourt, R and Jonsen, ID and Raymond, B and Maschette, D, Assessing the potential for resource competition between the Kerguelen Plateau fisheries and southern elephant seals, Frontiers in Marine Science, 9 Article 1006120. ISSN 2296-7745 (2022) [Refereed Article] http://ecite.utas.edu.au/155019 |
op_doi |
https://doi.org/10.3389/fmars.2022.1006120 |
container_title |
Frontiers in Marine Science |
container_volume |
9 |
_version_ |
1766401305538985984 |