Cetacean diversity of the eastern South Atlantic Ocean and Vema Seamount detected during a visual and passive acoustic survey, 2019
Abstract Cetaceans in the eastern South Atlantic Ocean are poorly studied. We present results from a 2 week ship-based survey from Cape Town to Vema Seamount (980 km to the west) during October–November 2019, including visual and towed-hydrophone observations from the vessel, and 10 days of acoustic...
Published in: | Journal of the Marine Biological Association of the United Kingdom |
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Cambridge University Press (CUP)
2023
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Online Access: | http://dx.doi.org/10.1017/s0025315423000255 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315423000255 |
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crcambridgeupr:10.1017/s0025315423000255 2024-03-03T08:37:34+00:00 Cetacean diversity of the eastern South Atlantic Ocean and Vema Seamount detected during a visual and passive acoustic survey, 2019 Elwen, Simon Fearey, Jack Ross-Marsh, Erin Thompson, Kirsten Maack, Thilo Webber, Thomas Gridley, Tess 2023 http://dx.doi.org/10.1017/s0025315423000255 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315423000255 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of the Marine Biological Association of the United Kingdom volume 103 ISSN 0025-3154 1469-7769 Aquatic Science journal-article 2023 crcambridgeupr https://doi.org/10.1017/s0025315423000255 2024-02-08T08:40:46Z Abstract Cetaceans in the eastern South Atlantic Ocean are poorly studied. We present results from a 2 week ship-based survey from Cape Town to Vema Seamount (980 km to the west) during October–November 2019, including visual and towed-hydrophone observations from the vessel, and 10 days of acoustic monitoring on the seamount. Fifty-two hours of visual surveys resulted in 39 encounters of whale groups including seven of humpback, six of fin and one sei whale, as well as four unidentified baleen whales, 18 unidentified balaenopterid whales and four unidentified odontocetes. Two humpback whales at the seamount were engaged in possible feeding behaviour. A large aggregation of mostly fin whales was observed near the continental shelf edge (22 encounters over a 70 × 50 km 2 area, six fin, one sei whale, 15 not confirmed to species), an historic whaling ground for both fin and sei whales. Towed-hydrophone data (78.7 h) detected five groups of sperm whales, 45 of delphinids, one beaked whale and no Kogiids. Acoustic data from the seamount detected calls from several baleen whale species including humpback whale non-song calls, Antarctic minke ‘bioduck’ calls, sei whale down-sweep calls and a likely Bryde's whale call. Two call types could not be assigned to species, including the most detected – a simple frequency-modulated call with peak power around 130 Hz. This study contributes to an improved understanding of cetacean occurrence in the eastern South Atlantic Ocean and highlights the need for more research to improve identification of cetacean vocalizations in the region. Article in Journal/Newspaper Antarc* Antarctic baleen whale baleen whales Humpback Whale Sei Whale South Atlantic Ocean Cambridge University Press Antarctic Journal of the Marine Biological Association of the United Kingdom 103 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Aquatic Science |
spellingShingle |
Aquatic Science Elwen, Simon Fearey, Jack Ross-Marsh, Erin Thompson, Kirsten Maack, Thilo Webber, Thomas Gridley, Tess Cetacean diversity of the eastern South Atlantic Ocean and Vema Seamount detected during a visual and passive acoustic survey, 2019 |
topic_facet |
Aquatic Science |
description |
Abstract Cetaceans in the eastern South Atlantic Ocean are poorly studied. We present results from a 2 week ship-based survey from Cape Town to Vema Seamount (980 km to the west) during October–November 2019, including visual and towed-hydrophone observations from the vessel, and 10 days of acoustic monitoring on the seamount. Fifty-two hours of visual surveys resulted in 39 encounters of whale groups including seven of humpback, six of fin and one sei whale, as well as four unidentified baleen whales, 18 unidentified balaenopterid whales and four unidentified odontocetes. Two humpback whales at the seamount were engaged in possible feeding behaviour. A large aggregation of mostly fin whales was observed near the continental shelf edge (22 encounters over a 70 × 50 km 2 area, six fin, one sei whale, 15 not confirmed to species), an historic whaling ground for both fin and sei whales. Towed-hydrophone data (78.7 h) detected five groups of sperm whales, 45 of delphinids, one beaked whale and no Kogiids. Acoustic data from the seamount detected calls from several baleen whale species including humpback whale non-song calls, Antarctic minke ‘bioduck’ calls, sei whale down-sweep calls and a likely Bryde's whale call. Two call types could not be assigned to species, including the most detected – a simple frequency-modulated call with peak power around 130 Hz. This study contributes to an improved understanding of cetacean occurrence in the eastern South Atlantic Ocean and highlights the need for more research to improve identification of cetacean vocalizations in the region. |
format |
Article in Journal/Newspaper |
author |
Elwen, Simon Fearey, Jack Ross-Marsh, Erin Thompson, Kirsten Maack, Thilo Webber, Thomas Gridley, Tess |
author_facet |
Elwen, Simon Fearey, Jack Ross-Marsh, Erin Thompson, Kirsten Maack, Thilo Webber, Thomas Gridley, Tess |
author_sort |
Elwen, Simon |
title |
Cetacean diversity of the eastern South Atlantic Ocean and Vema Seamount detected during a visual and passive acoustic survey, 2019 |
title_short |
Cetacean diversity of the eastern South Atlantic Ocean and Vema Seamount detected during a visual and passive acoustic survey, 2019 |
title_full |
Cetacean diversity of the eastern South Atlantic Ocean and Vema Seamount detected during a visual and passive acoustic survey, 2019 |
title_fullStr |
Cetacean diversity of the eastern South Atlantic Ocean and Vema Seamount detected during a visual and passive acoustic survey, 2019 |
title_full_unstemmed |
Cetacean diversity of the eastern South Atlantic Ocean and Vema Seamount detected during a visual and passive acoustic survey, 2019 |
title_sort |
cetacean diversity of the eastern south atlantic ocean and vema seamount detected during a visual and passive acoustic survey, 2019 |
publisher |
Cambridge University Press (CUP) |
publishDate |
2023 |
url |
http://dx.doi.org/10.1017/s0025315423000255 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315423000255 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic baleen whale baleen whales Humpback Whale Sei Whale South Atlantic Ocean |
genre_facet |
Antarc* Antarctic baleen whale baleen whales Humpback Whale Sei Whale South Atlantic Ocean |
op_source |
Journal of the Marine Biological Association of the United Kingdom volume 103 ISSN 0025-3154 1469-7769 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/s0025315423000255 |
container_title |
Journal of the Marine Biological Association of the United Kingdom |
container_volume |
103 |
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1792499853162446848 |