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International Whaling Commission/International Decade of Cetacean Research (IWC/IDCR) Southern Minke Whale assessment cruise, 1978–79

Published online by Cambridge University Press:  27 October 2009

Peter B. Best  and
Seiji Ohsumi
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Extract

The Minke Whale (Balaenoptera acutorostrata) represents the last major baleen whale resource of the Southern Ocean. Concerted exploitation for Minke Whales began in the 1971–72 season, so that it is especially important now that management of this species be placed on an adequate scientific basis.

Despite the accumulation of a considerable amount of basic information on the biological and population parameters of the species remarkably early in its history of exploitation (Ohsumi and others, 1970; Ohsumi and Masaki, 1975; Masaki, 1979), reliable estimates of stock size have proved extremely elusive. Initially, population estimates had to be based entirely on sightings (Ohsumi and Masaki, 1971) as trends in catch per unit of effort were not discernible. These estimates were variable, and sensitive to the extrapolation procedures used to cover areas or seasons for which no data were available. Eventually a decline in catch per unit effort was detected in one Southern Hemisphere Area, Area IV (70°E to 130°E), although this was not statistically significant (IWC, 1977). Most of the recent population estimates have been calculated (directly or indirectly) from an analysis of the decline in Area IV, with the results extrapolated to other Southern Hemisphere areas, based on relative densities from sightings information. Despite a rigorous analysis of catch per unit effort data at the Seattle meeting of the Scientific Committee of the International Whaling Commission (IWC) in May 1978, there was much variability in the Minke Whale population estimates—as much as 3.5 times, depending on the assumptions made (IWC, 1979)—causing the adequacy of assessments based solely on data from catch per unit effort to be questioned. The variability arose with the adoption of a deliberately conservative regime of exploitation (which should produce only a small change in relative abundance), and the reduced amount (and localized nature) of the effort used. Moreover, the only independent data available was based on sightings, and was too variable to place any confidence in detecting significant changes in abundance.

Type
Field Work
Information
Polar Record , Volume 20 , Issue 124 , January 1980 , pp. 52 - 57
Copyright
Copyright © Cambridge University Press 1980

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References

Best, P. B. and Butterworth, D. S. (in press). Report of the Southern Hemisphere Minke Whale assessment cruise, 1978–79. International Whaling Commission. Report, No 30.Google Scholar
International Whaling Commission. 1976. Scientific Committee. Report of special meeting, La Jolla 3–13 December 1974. International Whaling Commission. Report, No 26. (Supplementary vol: ‘Report and papers of the Scientific Committee of the Commission, 1975’), p 116–79.Google Scholar
International Whaling Commission. 1977. Report of the Scientific Committee. International Whaling Commission. Report, No 27, p 36–70.Google Scholar
International Whaling Commission. 1979. Report of the Scientific Committee. International Whaling Commission. Report, No 29, p 74–83.Google Scholar
Masaki, Y. 1979. Yearly change of the biological parameters for the Antarctic Minke Whale. International Whaling Commission. Report, No 29, p 375–95.Google Scholar
Mitchell, E. 1978. Minority statement on southern Minke stock assessment. International Whaling Commission. Report, No 28, p 84–85.Google Scholar
Ohsumi, S. and Masaki, Y. 1971. Revised estimates of population sizeand MSY of the Antarctic Minke Whale. (Unpublished document presented to the International Whaling Commission Scientific Committee, Washington, 1971, No SC/23/4.)Google Scholar
Ohsumi, S. and Masaki, Y. 1975. Biological parameters of the Antarctic Minke Whale at the virginal population level. Fisheries Research Board of Canada. Journal, Vol 32, No 7, p 995–1004.CrossRefGoogle Scholar
Ohsumi, S.and others. 1970. Stock of the Antarctic Minke Whale. Whales Research Institute. Scientific Reports, No 22, p 75–125.Google Scholar
Robson, D. S. and Regier, H. A. 1964. Sample size in Petersen mark-recapture experiments. American Fisheries Society. Transactions, Vol 93, p 215–26.CrossRefGoogle Scholar