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SC/69B/ASI/09
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Resource ID
22011
Access
Open
Document Number
SC/69B/ASI/09
Full Title
Results of the Japanese dedicated cetacean sighting survey in the North Pacific in 2023 summer season
Author
Yujin Kim, Tatsuya Isoda, Masanori Higashi, Masahiro Yamazaki, Ayato Arito, Hidenori Kasai And Koji Matsuoka
Authors Summary
Summary to come
Publisher
IWC
Publication Year
2024
Abstract
A systematic large-scale vessel-based sighting survey was conducted in summer 2023 by Japan to examine the distribution and abundance of large whales in the North Pacific. The research area was set between 20øN?30øN and 140øE?180ø. The survey was conducted between 28 July and 5 October. The research vessels Yushin-Maru and Kaiyo-Maru No.7 were engaged in the surveys. A total of 5,631.4 n.miles was searched by the passing mode in the research area. Coverage of the searching effort on the planned cruise track line was 83.1%. In total, two large whale species were sighted: Bryde's (32 schools/33 individuals) and sperm (26/54) whales. Despite effort was spent, photo-ID images and biopsy skin samples could not be obtained. The highlight of this survey was that fewer Bryde's whales were sighted in comparison with a previous survey conducted in a similar area despite the SST was not significantly different between the previous and current surveys. The sighting data will be used for abundance estimates of Bryde?s and sperm whales.