Publication Date:
2022-05-26
Description:
© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Buchan, S. J., Gutierrez, L., Balcazar-Cabrera, N., & Stafford, K. M. Seasonal occurrence of fin whale song off Juan Fernandez, Chile. Endangered Species Research, 39, (2019): 135-145, doi:10.3354/esr00956.
Description:
Fin whales Balaenoptera physalus were the species of baleen whale most widely caught by commercial whaling fleets off the Chilean coast and are globally classified as Endangered. However, very little is known about the present distribution and seasonal movements of fin whales off the coast of Chile. Passive acoustic data collected at the HA03 station of the Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization off the Juan Fernandez Archipelago (JFA) between 2007 and 2016 were analyzed. The temporal occurrence of fin whale song was examined using automatic detection via spectrogram cross-correlation of song notes and by calculating the average acoustic power in the frequency bands of fin whale song. Fin whale song off JFA was composed of regular 17 Hz notes associated with high-frequency components at 85 Hz, with singlet phrasing at a dominant primary inter-note interval of 14.4 s and a secondary interval of 30.8 s. There was a clear seasonal pattern in acoustic presence that was consistent across all years: low or no song during the austral summer and a peak in song occurrence in austral winter. A propagation loss model estimated the detection range at this site to be 186 km. Where the fin whales that are heard off JFA spend the summer months remains an open question. Possible locations include the Western Antarctic Peninsula and/or off northern-central mainland Chile. Further studies should be pursued to better understand the distribution and seasonal movements and to support the conservation of this Endangered species.
Description:
We thank the Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization and the Chilean Commission of Nuclear Energy for proving the data used in this study. S.J.B. and N.B.C. were supported by the Center for Oceanographic Research COPAS Sur-Austral, CONICYT PIA PFB31. S.J.B. was also supported during analysis and writing by the Office of Naval Research Global (awards N62909-16-2214 and N00014-17-2606), and a grant to the Centro de Estudios Avanzados enZonas Áridas (CEAZA) ‘Proyecto CEAZA, 3er Fortalec-imiento de Centros Regionales, Programa Regional CONI-CYT R16A10003’. Our greatest thanks to John Hodgson MSc, Technical Director at Ocean Acoustic Developments and Adrian Brown of the Defence Science and Technology Laboratory (UK) for carrying out the propagation modelling free of charge. Many thanks to Rex Andrew for his help with PSD figure preparation in R. Thanks also go to Nathan Merchant for his kind help with PAMGuide. Many thanks to Michael Pitzrick for his guidance with XBAT. Many thanks to the members of the Southern Ocean Research Partnership Blue and Fin Whale Acoustic Trends Working group for useful discussions that improved the quality of this study.
Keywords:
Fin whale
;
Balaenoptera physalus
;
Juan Fernandez
;
Chile
;
Southeast Pacific
;
Passive acoustic monitoring
Repository Name:
Woods Hole Open Access Server
Type:
Article
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