Broad-scale study of the seasonal and geographic occurrence of blue and fin whales in the Southern Indian Ocean
The southern Indian Ocean is believed to be a natural territory for blue and fin whales. However, decades after commercial and illegal whaling decimated these populations, little is known about their current status, seasonal habitat or movements. Recent passive acoustic studies have described the pr...
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ftarchimer:oai:archimer.ifremer.fr:62731 2023-05-15T13:47:36+02:00 Broad-scale study of the seasonal and geographic occurrence of blue and fin whales in the Southern Indian Ocean Leroy, Emmanuelle C. Samaran, Flore Stafford, Kathleen M. Bonnel, Julien Royer, Jean-yves 2018 application/pdf https://archimer.ifremer.fr/doc/00516/62731/67110.pdf https://archimer.ifremer.fr/doc/00516/62731/67111.pdf https://doi.org/10.3354/esr00927 https://archimer.ifremer.fr/doc/00516/62731/ eng eng Inter-research https://archimer.ifremer.fr/doc/00516/62731/67110.pdf https://archimer.ifremer.fr/doc/00516/62731/67111.pdf doi:10.3354/esr00927 https://archimer.ifremer.fr/doc/00516/62731/ info:eu-repo/semantics/openAccess restricted use Endangered Species Research (1863-5407) (Inter-research), 2018 , Vol. 37 , P. 289-300 Pygmy blue whales Antarctic blue whales Fin whales Southern Indian Ocean Passive acoustic monitoring Sympatry text Publication info:eu-repo/semantics/article 2018 ftarchimer https://doi.org/10.3354/esr00927 2021-09-23T20:33:28Z The southern Indian Ocean is believed to be a natural territory for blue and fin whales. However, decades after commercial and illegal whaling decimated these populations, little is known about their current status, seasonal habitat or movements. Recent passive acoustic studies have described the presence of 4 acoustic populations of blue whales (Antarctic and 3 'pygmy' types), but are generally limited temporally and geographically. Here, we examine up to 7 yr of continuous acoustic recordings (2010-2016) from a hydrophone network of 6 widely spaced sites in the southern Indian Ocean, looking for the presence of Antarctic and pygmy blue and fin whales. Power spectral density analyses of characteristic and distinct frequency bands of these species show seasonal and geographic differences among the different populations, and the overall patterns for each display interannual consistencies in timing and occurrence. Antarctic blue and fin whales are recorded across the hydrophone network, mainly from austral autumn to spring, with peak intensity in winter. Pygmy blue whales show spatial variation: Madagascan pygmy blue whales are mainly present in the west of the network, while the Australian call type is heard at the eastern sites. Both populations share a common seasonality, with a presence from January to June. Finally, the Sri Lankan call type is recorded only on a single site in the northeast. These results confirm the importance of the southern Indian Ocean for several populations of endangered large whales and present the first long-term assessment of fin whales in the southern Indian Ocean. Article in Journal/Newspaper Antarc* Antarctic Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Antarctic Austral Indian Endangered Species Research 37 289 300 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
Pygmy blue whales Antarctic blue whales Fin whales Southern Indian Ocean Passive acoustic monitoring Sympatry |
spellingShingle |
Pygmy blue whales Antarctic blue whales Fin whales Southern Indian Ocean Passive acoustic monitoring Sympatry Leroy, Emmanuelle C. Samaran, Flore Stafford, Kathleen M. Bonnel, Julien Royer, Jean-yves Broad-scale study of the seasonal and geographic occurrence of blue and fin whales in the Southern Indian Ocean |
topic_facet |
Pygmy blue whales Antarctic blue whales Fin whales Southern Indian Ocean Passive acoustic monitoring Sympatry |
description |
The southern Indian Ocean is believed to be a natural territory for blue and fin whales. However, decades after commercial and illegal whaling decimated these populations, little is known about their current status, seasonal habitat or movements. Recent passive acoustic studies have described the presence of 4 acoustic populations of blue whales (Antarctic and 3 'pygmy' types), but are generally limited temporally and geographically. Here, we examine up to 7 yr of continuous acoustic recordings (2010-2016) from a hydrophone network of 6 widely spaced sites in the southern Indian Ocean, looking for the presence of Antarctic and pygmy blue and fin whales. Power spectral density analyses of characteristic and distinct frequency bands of these species show seasonal and geographic differences among the different populations, and the overall patterns for each display interannual consistencies in timing and occurrence. Antarctic blue and fin whales are recorded across the hydrophone network, mainly from austral autumn to spring, with peak intensity in winter. Pygmy blue whales show spatial variation: Madagascan pygmy blue whales are mainly present in the west of the network, while the Australian call type is heard at the eastern sites. Both populations share a common seasonality, with a presence from January to June. Finally, the Sri Lankan call type is recorded only on a single site in the northeast. These results confirm the importance of the southern Indian Ocean for several populations of endangered large whales and present the first long-term assessment of fin whales in the southern Indian Ocean. |
format |
Article in Journal/Newspaper |
author |
Leroy, Emmanuelle C. Samaran, Flore Stafford, Kathleen M. Bonnel, Julien Royer, Jean-yves |
author_facet |
Leroy, Emmanuelle C. Samaran, Flore Stafford, Kathleen M. Bonnel, Julien Royer, Jean-yves |
author_sort |
Leroy, Emmanuelle C. |
title |
Broad-scale study of the seasonal and geographic occurrence of blue and fin whales in the Southern Indian Ocean |
title_short |
Broad-scale study of the seasonal and geographic occurrence of blue and fin whales in the Southern Indian Ocean |
title_full |
Broad-scale study of the seasonal and geographic occurrence of blue and fin whales in the Southern Indian Ocean |
title_fullStr |
Broad-scale study of the seasonal and geographic occurrence of blue and fin whales in the Southern Indian Ocean |
title_full_unstemmed |
Broad-scale study of the seasonal and geographic occurrence of blue and fin whales in the Southern Indian Ocean |
title_sort |
broad-scale study of the seasonal and geographic occurrence of blue and fin whales in the southern indian ocean |
publisher |
Inter-research |
publishDate |
2018 |
url |
https://archimer.ifremer.fr/doc/00516/62731/67110.pdf https://archimer.ifremer.fr/doc/00516/62731/67111.pdf https://doi.org/10.3354/esr00927 https://archimer.ifremer.fr/doc/00516/62731/ |
geographic |
Antarctic Austral Indian |
geographic_facet |
Antarctic Austral Indian |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Endangered Species Research (1863-5407) (Inter-research), 2018 , Vol. 37 , P. 289-300 |
op_relation |
https://archimer.ifremer.fr/doc/00516/62731/67110.pdf https://archimer.ifremer.fr/doc/00516/62731/67111.pdf doi:10.3354/esr00927 https://archimer.ifremer.fr/doc/00516/62731/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.3354/esr00927 |
container_title |
Endangered Species Research |
container_volume |
37 |
container_start_page |
289 |
op_container_end_page |
300 |
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1766247513423085568 |