Importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions
© 2019 Inter-Research. All Rights Reserved. Fisheries may generate new feeding opportunities for marine predators, which switch foraging behaviour to depredation when they feed on fish directly from fishing gear. However, the role of diet in the propensity of individuals to depredate and whether the...
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ftdeakinunifig:oai:figshare.com:article/20763370 2024-06-23T07:51:35+00:00 Importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions P Tixie J Giménez RR Reisinge P Méndez-Fernandez John Arnould Y Cherel C Guinet 2019-01-01T00:00:00Z http://hdl.handle.net/10536/DRO/DU:30120328 https://figshare.com/articles/journal_contribution/Importance_of_toothfish_in_the_diet_of_generalist_subantarctic_killer_whales_implications_for_fisheries_interactions/20763370 unknown http://hdl.handle.net/10536/DRO/DU:30120328 https://figshare.com/articles/journal_contribution/Importance_of_toothfish_in_the_diet_of_generalist_subantarctic_killer_whales_implications_for_fisheries_interactions/20763370 All Rights Reserved Ecology not elsewhere classified Zoology not elsewhere classified Oceanography not elsewhere classified Science & Technology Life Sciences & Biomedicine Physical Sciences Ecology Marine & Freshwater Biology Oceanography Environmental Sciences & Ecology Diet Fisheries Southern Ocean Killer whale Stable isotopes Fishery interactions ORCINUS-ORCA PATAGONIAN TOOTHFISH STABLE-ISOTOPE SOUTHERN-OCEAN CROZET ARCHIPELAGO LIPID EXTRACTION FEEDING ECOLOGY MARINE MAMMALS BLUEFIN TUNA SPERM-WHALES 3103 Ecology 3109 Zoology Text Journal contribution 2019 ftdeakinunifig 2024-06-06T02:05:01Z © 2019 Inter-Research. All Rights Reserved. Fisheries may generate new feeding opportunities for marine predators, which switch foraging behaviour to depredation when they feed on fish directly from fishing gear. However, the role of diet in the propensity of individuals to depredate and whether the depredated resource is artificial or part of the natural diet of individuals is often unclear. Using stable isotopes, this study investigated the importance of the commercially exploited Patagonian toothfish Dissostichus eleginoides in the diet of generalist subantarctic killer whales Orcinus orca depredating this fish at Crozet (45°S, 50°E). The isotopic niche of these killer whales was large and overlapped with that of sperm whales Physeter macrocephalus from the same region, which feed on toothfish both naturally and through depredation. There was no isotopic difference between killer whales that depredated toothfish and those that did not. Isotopic mixing models indicated that prey groups including large/medium sized toothfish and elephant seal Mirounga leonina pups represented ~60% of the diet relative to prey groups including penguins, baleen whales and coastal fish. These results indicate that toothfish are an important natural prey item of Crozet killer whales and that switching to depredation primarily occurs when fisheries facilitate access to that resource. This study suggests that toothfish, as a commercial species, may also have a key role as prey for top predators in subantarctic ecosystems. Therefore, assessing the extent to which predators use that resource naturally or from fisheries is now needed to improve both fish stock management and species conservation strategies. Article in Journal/Newspaper baleen whales Elephant Seal Killer Whale Mirounga leonina Orca Orcinus orca Patagonian Toothfish Physeter macrocephalus Southern Ocean Killer whale DRO - Deakin Research Online Southern Ocean |
institution |
Open Polar |
collection |
DRO - Deakin Research Online |
op_collection_id |
ftdeakinunifig |
language |
unknown |
topic |
Ecology not elsewhere classified Zoology not elsewhere classified Oceanography not elsewhere classified Science & Technology Life Sciences & Biomedicine Physical Sciences Ecology Marine & Freshwater Biology Oceanography Environmental Sciences & Ecology Diet Fisheries Southern Ocean Killer whale Stable isotopes Fishery interactions ORCINUS-ORCA PATAGONIAN TOOTHFISH STABLE-ISOTOPE SOUTHERN-OCEAN CROZET ARCHIPELAGO LIPID EXTRACTION FEEDING ECOLOGY MARINE MAMMALS BLUEFIN TUNA SPERM-WHALES 3103 Ecology 3109 Zoology |
spellingShingle |
Ecology not elsewhere classified Zoology not elsewhere classified Oceanography not elsewhere classified Science & Technology Life Sciences & Biomedicine Physical Sciences Ecology Marine & Freshwater Biology Oceanography Environmental Sciences & Ecology Diet Fisheries Southern Ocean Killer whale Stable isotopes Fishery interactions ORCINUS-ORCA PATAGONIAN TOOTHFISH STABLE-ISOTOPE SOUTHERN-OCEAN CROZET ARCHIPELAGO LIPID EXTRACTION FEEDING ECOLOGY MARINE MAMMALS BLUEFIN TUNA SPERM-WHALES 3103 Ecology 3109 Zoology P Tixie J Giménez RR Reisinge P Méndez-Fernandez John Arnould Y Cherel C Guinet Importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions |
topic_facet |
Ecology not elsewhere classified Zoology not elsewhere classified Oceanography not elsewhere classified Science & Technology Life Sciences & Biomedicine Physical Sciences Ecology Marine & Freshwater Biology Oceanography Environmental Sciences & Ecology Diet Fisheries Southern Ocean Killer whale Stable isotopes Fishery interactions ORCINUS-ORCA PATAGONIAN TOOTHFISH STABLE-ISOTOPE SOUTHERN-OCEAN CROZET ARCHIPELAGO LIPID EXTRACTION FEEDING ECOLOGY MARINE MAMMALS BLUEFIN TUNA SPERM-WHALES 3103 Ecology 3109 Zoology |
description |
© 2019 Inter-Research. All Rights Reserved. Fisheries may generate new feeding opportunities for marine predators, which switch foraging behaviour to depredation when they feed on fish directly from fishing gear. However, the role of diet in the propensity of individuals to depredate and whether the depredated resource is artificial or part of the natural diet of individuals is often unclear. Using stable isotopes, this study investigated the importance of the commercially exploited Patagonian toothfish Dissostichus eleginoides in the diet of generalist subantarctic killer whales Orcinus orca depredating this fish at Crozet (45°S, 50°E). The isotopic niche of these killer whales was large and overlapped with that of sperm whales Physeter macrocephalus from the same region, which feed on toothfish both naturally and through depredation. There was no isotopic difference between killer whales that depredated toothfish and those that did not. Isotopic mixing models indicated that prey groups including large/medium sized toothfish and elephant seal Mirounga leonina pups represented ~60% of the diet relative to prey groups including penguins, baleen whales and coastal fish. These results indicate that toothfish are an important natural prey item of Crozet killer whales and that switching to depredation primarily occurs when fisheries facilitate access to that resource. This study suggests that toothfish, as a commercial species, may also have a key role as prey for top predators in subantarctic ecosystems. Therefore, assessing the extent to which predators use that resource naturally or from fisheries is now needed to improve both fish stock management and species conservation strategies. |
format |
Article in Journal/Newspaper |
author |
P Tixie J Giménez RR Reisinge P Méndez-Fernandez John Arnould Y Cherel C Guinet |
author_facet |
P Tixie J Giménez RR Reisinge P Méndez-Fernandez John Arnould Y Cherel C Guinet |
author_sort |
P Tixie |
title |
Importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions |
title_short |
Importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions |
title_full |
Importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions |
title_fullStr |
Importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions |
title_full_unstemmed |
Importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions |
title_sort |
importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions |
publishDate |
2019 |
url |
http://hdl.handle.net/10536/DRO/DU:30120328 https://figshare.com/articles/journal_contribution/Importance_of_toothfish_in_the_diet_of_generalist_subantarctic_killer_whales_implications_for_fisheries_interactions/20763370 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
baleen whales Elephant Seal Killer Whale Mirounga leonina Orca Orcinus orca Patagonian Toothfish Physeter macrocephalus Southern Ocean Killer whale |
genre_facet |
baleen whales Elephant Seal Killer Whale Mirounga leonina Orca Orcinus orca Patagonian Toothfish Physeter macrocephalus Southern Ocean Killer whale |
op_relation |
http://hdl.handle.net/10536/DRO/DU:30120328 https://figshare.com/articles/journal_contribution/Importance_of_toothfish_in_the_diet_of_generalist_subantarctic_killer_whales_implications_for_fisheries_interactions/20763370 |
op_rights |
All Rights Reserved |
_version_ |
1802642708031864832 |