Long-term and seasonal changes of large whale call frequency in the Southern Indian Ocean
Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 1123(11), (2018): 8568-8580. doi:10.1029/2018JC014352. In the...
Published in: | Journal of Geophysical Research: Oceans |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
American Geophysical Union
2018
|
Subjects: | |
Online Access: | https://hdl.handle.net/1912/10837 |
id |
ftwhoas:oai:darchive.mblwhoilibrary.org:1912/10837 |
---|---|
record_format |
openpolar |
spelling |
ftwhoas:oai:darchive.mblwhoilibrary.org:1912/10837 2023-05-15T13:48:31+02:00 Long-term and seasonal changes of large whale call frequency in the Southern Indian Ocean Leroy, Emmanuelle C. Royer, Jean-Yves Bonnel, Julien Samaran, Flore 2018-11-27 https://hdl.handle.net/1912/10837 unknown American Geophysical Union https://doi.org/10.1029/2018JC014352 Leroy, E. C., Royer, J.-Y., Bonnel, J., & Samaran, F. (2018). Long-term and seasonal changes of large whale call frequency in the southern Indian Ocean. Journal of Geophysical Research: Oceans, 123, 8568–8580. https://hdl.handle.net/1912/10837 doi:10.1029/2018JC014352 Leroy, E. C., Royer, J.-Y., Bonnel, J., & Samaran, F. (2018). Long-term and seasonal changes of large whale call frequency in the southern Indian Ocean. Journal of Geophysical Research: Oceans, 123, 8568–8580. doi:10.1029/2018JC014352 Large baleen whales Blue whale calls Frequency decrease Bioacoustics Frequency shifts Ambient noise Article 2018 ftwhoas https://doi.org/10.1029/2018JC014352 2022-10-22T22:57:09Z Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 1123(11), (2018): 8568-8580. doi:10.1029/2018JC014352. In the past decades, in the context of a changing ocean submitted to an increasing human activity, a progressive decrease in the frequencies (pitch) of blue whale vocalizations has been observed worldwide. Its causes, of natural or anthropogenic nature, are still unclear. Based on 7 years of continuous acoustic recordings at widespread sites in the southern Indian Ocean, we show that this observation stands for five populations of large whales. The frequency of selected units of vocalizations of fin, Antarctic, and pygmy blue whales has steadily decreased at a rate of a few tenths of hertz per year since 2002. In addition to this interannual frequency decrease, blue whale vocalizations display seasonal frequency shifts. We show that these intra‐annual shifts correlate with seasonal changes in the ambient noise near their call frequency. This ambient noise level, in turn, shows a strong correlation with the seasonal presence of icebergs, which are one of the main sources of oceanic noise in the Southern Hemisphere. Although cause‐and‐effect relationships are difficult to ascertain, wide‐ranging changes in the acoustic environment seem to have a strong impact on the vocal behavior of large baleen whales. Seasonal frequency shifts may be due to short‐term changes in the ambient noise, and the interannual frequency decline to long‐term changes in the acoustic properties of the ocean and/or in postwhaling changes in whale abundances. The authors wish to thank the Captains and crews of RV Marion Dufresne for the successful deployments and recoveries of the hydrophones of the DEFLOHYDRO (Royer, 2008) and OHASISBIO (Royer, 2009) experiments. French cruises were funded by the French Polar Institute (IPEV) with additional support ... Article in Journal/Newspaper Antarc* Antarctic baleen whales Blue whale Iceberg* Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Antarctic Indian Journal of Geophysical Research: Oceans 123 11 8568 8580 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
unknown |
topic |
Large baleen whales Blue whale calls Frequency decrease Bioacoustics Frequency shifts Ambient noise |
spellingShingle |
Large baleen whales Blue whale calls Frequency decrease Bioacoustics Frequency shifts Ambient noise Leroy, Emmanuelle C. Royer, Jean-Yves Bonnel, Julien Samaran, Flore Long-term and seasonal changes of large whale call frequency in the Southern Indian Ocean |
topic_facet |
Large baleen whales Blue whale calls Frequency decrease Bioacoustics Frequency shifts Ambient noise |
description |
Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 1123(11), (2018): 8568-8580. doi:10.1029/2018JC014352. In the past decades, in the context of a changing ocean submitted to an increasing human activity, a progressive decrease in the frequencies (pitch) of blue whale vocalizations has been observed worldwide. Its causes, of natural or anthropogenic nature, are still unclear. Based on 7 years of continuous acoustic recordings at widespread sites in the southern Indian Ocean, we show that this observation stands for five populations of large whales. The frequency of selected units of vocalizations of fin, Antarctic, and pygmy blue whales has steadily decreased at a rate of a few tenths of hertz per year since 2002. In addition to this interannual frequency decrease, blue whale vocalizations display seasonal frequency shifts. We show that these intra‐annual shifts correlate with seasonal changes in the ambient noise near their call frequency. This ambient noise level, in turn, shows a strong correlation with the seasonal presence of icebergs, which are one of the main sources of oceanic noise in the Southern Hemisphere. Although cause‐and‐effect relationships are difficult to ascertain, wide‐ranging changes in the acoustic environment seem to have a strong impact on the vocal behavior of large baleen whales. Seasonal frequency shifts may be due to short‐term changes in the ambient noise, and the interannual frequency decline to long‐term changes in the acoustic properties of the ocean and/or in postwhaling changes in whale abundances. The authors wish to thank the Captains and crews of RV Marion Dufresne for the successful deployments and recoveries of the hydrophones of the DEFLOHYDRO (Royer, 2008) and OHASISBIO (Royer, 2009) experiments. French cruises were funded by the French Polar Institute (IPEV) with additional support ... |
format |
Article in Journal/Newspaper |
author |
Leroy, Emmanuelle C. Royer, Jean-Yves Bonnel, Julien Samaran, Flore |
author_facet |
Leroy, Emmanuelle C. Royer, Jean-Yves Bonnel, Julien Samaran, Flore |
author_sort |
Leroy, Emmanuelle C. |
title |
Long-term and seasonal changes of large whale call frequency in the Southern Indian Ocean |
title_short |
Long-term and seasonal changes of large whale call frequency in the Southern Indian Ocean |
title_full |
Long-term and seasonal changes of large whale call frequency in the Southern Indian Ocean |
title_fullStr |
Long-term and seasonal changes of large whale call frequency in the Southern Indian Ocean |
title_full_unstemmed |
Long-term and seasonal changes of large whale call frequency in the Southern Indian Ocean |
title_sort |
long-term and seasonal changes of large whale call frequency in the southern indian ocean |
publisher |
American Geophysical Union |
publishDate |
2018 |
url |
https://hdl.handle.net/1912/10837 |
geographic |
Antarctic Indian |
geographic_facet |
Antarctic Indian |
genre |
Antarc* Antarctic baleen whales Blue whale Iceberg* |
genre_facet |
Antarc* Antarctic baleen whales Blue whale Iceberg* |
op_source |
Leroy, E. C., Royer, J.-Y., Bonnel, J., & Samaran, F. (2018). Long-term and seasonal changes of large whale call frequency in the southern Indian Ocean. Journal of Geophysical Research: Oceans, 123, 8568–8580. doi:10.1029/2018JC014352 |
op_relation |
https://doi.org/10.1029/2018JC014352 Leroy, E. C., Royer, J.-Y., Bonnel, J., & Samaran, F. (2018). Long-term and seasonal changes of large whale call frequency in the southern Indian Ocean. Journal of Geophysical Research: Oceans, 123, 8568–8580. https://hdl.handle.net/1912/10837 doi:10.1029/2018JC014352 |
op_doi |
https://doi.org/10.1029/2018JC014352 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
123 |
container_issue |
11 |
container_start_page |
8568 |
op_container_end_page |
8580 |
_version_ |
1766249378664677376 |