Contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the Crozet Islands: a multi-scale bioenergetic approach
Fisheries modify prey availability for marine predators by extracting resources but also by providing them with new feeding opportunities. Among these, depredation, which occurs when predators feed on fish caught on fishing gear, is a behavior developed by many species as a way to acquire food throu...
Published in: | Marine Ecology Progress Series |
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Inter Research
2021
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Online Access: | https://oskar-bordeaux.fr/handle/20.500.12278/37851 https://doi.org/10.3354/meps13725 |
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ftoskarbordeaux:oai:oskar-bordeaux.fr:20.500.12278/37851 2023-05-15T15:59:31+02:00 Contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the Crozet Islands: a multi-scale bioenergetic approach FAURE, Johanna PÉRON, Clara GASCO, Nicolas MASSIOT-GRANIER, Félix SPITZ, Jérôme GUINET, Christophe TIXIER, Paul 2021-05-10T16:34:27Z https://oskar-bordeaux.fr/handle/20.500.12278/37851 https://doi.org/10.3354/meps13725 en eng Inter Research 0171-8630 https://oskar-bordeaux.fr/handle/20.500.12278/37851 doi:10.3354/meps13725 Sciences de l'environnement Article de revue 2021 ftoskarbordeaux https://doi.org/10.3354/meps13725 2021-05-11T22:30:07Z Fisheries modify prey availability for marine predators by extracting resources but also by providing them with new feeding opportunities. Among these, depredation, which occurs when predators feed on fish caught on fishing gear, is a behavior developed by many species as a way to acquire food through limited foraging effort. However, the extent to which depredated resources from fisheries contribute to the energetic requirements and affect demography of depredating individuals is unknown. We investigated the contribution of Patagonian toothfish Dissostichus eleginoides depredated on longlines to the energetic requirements of killer whales Orcinus orca around the Crozet islands (Southern Indian Ocean) over the period 2007–2018. Our results indicate that during days when depredation occurred, depredating individuals fulfilled on average 94.1% of their daily energetic requirements with depredated toothfish. However, the contribution varied from 1.2 to 13.3% of the monthly energetic requirements and from 2.4 to 8.8% of the yearly energetic requirements of the total population. Together, these findings suggest that intake of depredated toothfish can be substantial at fine scale (daily and individually), potentially leading to temporary provisioning effects and changes in predation pressures. These effects become minor (<10), however, when considering the full population over a whole year. The contribution of depredated fish to the annual energetic requirements of the population has yet increased in recent years, likely due to larger fishing quotas and greater opportunities for whales to depredate, which stresses the importance of accounting for depredation in ecosystem-based management of fishing activity. Other/Unknown Material Crozet Islands Orca Orcinus orca Patagonian Toothfish OSKAR Bordeaux (Open Science Knowledge ARchive) Indian Marine Ecology Progress Series 668 149 161 |
institution |
Open Polar |
collection |
OSKAR Bordeaux (Open Science Knowledge ARchive) |
op_collection_id |
ftoskarbordeaux |
language |
English |
topic |
Sciences de l'environnement |
spellingShingle |
Sciences de l'environnement FAURE, Johanna PÉRON, Clara GASCO, Nicolas MASSIOT-GRANIER, Félix SPITZ, Jérôme GUINET, Christophe TIXIER, Paul Contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the Crozet Islands: a multi-scale bioenergetic approach |
topic_facet |
Sciences de l'environnement |
description |
Fisheries modify prey availability for marine predators by extracting resources but also by providing them with new feeding opportunities. Among these, depredation, which occurs when predators feed on fish caught on fishing gear, is a behavior developed by many species as a way to acquire food through limited foraging effort. However, the extent to which depredated resources from fisheries contribute to the energetic requirements and affect demography of depredating individuals is unknown. We investigated the contribution of Patagonian toothfish Dissostichus eleginoides depredated on longlines to the energetic requirements of killer whales Orcinus orca around the Crozet islands (Southern Indian Ocean) over the period 2007–2018. Our results indicate that during days when depredation occurred, depredating individuals fulfilled on average 94.1% of their daily energetic requirements with depredated toothfish. However, the contribution varied from 1.2 to 13.3% of the monthly energetic requirements and from 2.4 to 8.8% of the yearly energetic requirements of the total population. Together, these findings suggest that intake of depredated toothfish can be substantial at fine scale (daily and individually), potentially leading to temporary provisioning effects and changes in predation pressures. These effects become minor (<10), however, when considering the full population over a whole year. The contribution of depredated fish to the annual energetic requirements of the population has yet increased in recent years, likely due to larger fishing quotas and greater opportunities for whales to depredate, which stresses the importance of accounting for depredation in ecosystem-based management of fishing activity. |
format |
Other/Unknown Material |
author |
FAURE, Johanna PÉRON, Clara GASCO, Nicolas MASSIOT-GRANIER, Félix SPITZ, Jérôme GUINET, Christophe TIXIER, Paul |
author_facet |
FAURE, Johanna PÉRON, Clara GASCO, Nicolas MASSIOT-GRANIER, Félix SPITZ, Jérôme GUINET, Christophe TIXIER, Paul |
author_sort |
FAURE, Johanna |
title |
Contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the Crozet Islands: a multi-scale bioenergetic approach |
title_short |
Contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the Crozet Islands: a multi-scale bioenergetic approach |
title_full |
Contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the Crozet Islands: a multi-scale bioenergetic approach |
title_fullStr |
Contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the Crozet Islands: a multi-scale bioenergetic approach |
title_full_unstemmed |
Contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the Crozet Islands: a multi-scale bioenergetic approach |
title_sort |
contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the crozet islands: a multi-scale bioenergetic approach |
publisher |
Inter Research |
publishDate |
2021 |
url |
https://oskar-bordeaux.fr/handle/20.500.12278/37851 https://doi.org/10.3354/meps13725 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
Crozet Islands Orca Orcinus orca Patagonian Toothfish |
genre_facet |
Crozet Islands Orca Orcinus orca Patagonian Toothfish |
op_relation |
0171-8630 https://oskar-bordeaux.fr/handle/20.500.12278/37851 doi:10.3354/meps13725 |
op_doi |
https://doi.org/10.3354/meps13725 |
container_title |
Marine Ecology Progress Series |
container_volume |
668 |
container_start_page |
149 |
op_container_end_page |
161 |
_version_ |
1766395472308600832 |