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SC/67B/SH/08 Rev2
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Resource ID
9321
Access
Open
Document Number
SC/67B/SH/08 Rev2
Full Title
Capture-recapture estimates of abundance of Antarctic blue whales
Author
Paula A. Olson, Douglas Kinzey, Michael C. Double, Koji Matsuoka, Luis A. Pastene, Ken Findlay
Publisher
International Whaling Commission
Publication Year
2018
Abstract
ABSTRACT
Photo-identification data of Antarctic blue whales from 1990/91 to 2014/15 were used in a capture-recapture analysis to produce estimates of super-population abundance for the circumpolar Antarctic. An estimate for IWC Management Area III 1992/93 to 2013/14 was also produced. Photographs were collected during IWC, IWC-SORP, ICR, and SAABWS cruises and also made available by opportunistic contributors. The circumpolar estimates are 4,629 (95% CI 2,563 to 8,558) Antarctic blue whales (left side photographs) and 4,485 (95% CI 2,514 to 8,192) (right side photographs) for the years 1990/91 to 2014/15. These estimates show improved precision with the addition of 30% more photo-ID data than was available for a previous capture-recapture study based on data from 1992/93 to 2008/09. Estimates of abundance for Area III are 1,944 (95% CI 903 to 4,390) (left side photographs) and 2,575 (95% CI 1,089 to 6,380) (right side photographs). As more data become available in the future, the reliability of capture-recapture estimates should improve.