Chapter FV — International 



Status. The Committee agreed that, for future assess- 

 ments, it would need to determine first whether 

 adequate data were available. If not, data needs 

 would have to be identified and satisfied before 

 proceeding with the assessment. To address these 

 problems, the Committee established a working group 

 on population assessment models to develop reliable 

 population models to integrate biological and abun- 

 dance data. 



As discussed in Chapter 11, at its 1991 meeting, the 

 Scientific Committee undertook a comprehensive 

 assessment of the Bering-Chukchi-Beaufort Seas stock 

 of bowhead whales. The assessment produced a new 

 estimated initial (1848) population size of 12,400- 

 18,200 whales; a current population estimate of 7,500 

 whales (95 percent confidence interval 6,400 to 

 9,200); a provisional rate of annual increase of 3.1 

 percent (95 percent confidence interval 0.1 percent to 

 6.2 percent) from 1978 to 1988; and a minimum 

 estimate of annual replacement yield of 92 whales. 

 This new assessment suggests that the Bering-Chuk- 

 chi-Beaufort Seas stock has increased under relatively 

 consistent subsistence catches of approximately 0.3 

 percent per year and that the stock may be closer to 

 its maximum net productivity level than previously 

 thought. 



The Scientific Committee also conducted a compre- 

 hensive assessment of western North Pacific minke 

 whales at its 1991 meeting. It concluded that there 

 are at least two stocks of minke whales — the Ok- 

 hotsk Sea-West Pacific stock and the protected Sea of 

 Japan-Yellow Sea-East China Sea stock — that mix to 

 some unknown degree in the area north of Japan in 

 early spring. The Committee concluded that, if 

 exploited, individuals from both stocks would be 

 likely subject to harvests in the area where they 

 overlap and, therefore, each stock would need to be 

 managed separately. Despite inadequate biological 

 information, the Committee concluded that, for the 

 Okhotsk Sea-West Pacific stock, the best estimate of 

 population size in the Okhotsk Sea was 19,209 ani- 

 mals (95 percent confidence interval 10,069 to 

 36,645) and the best estimate of population size in the 

 northwest Pacific was 5,841 animals (95 percent 

 confidence interval of 2,835 to 12,032) with a com- 

 bined population size of 25,049 whales (95 percent 

 confidence interval of 13,689 to 45,835). Because of 



the wide range of the confidence intervals for these 

 estimates, it was impossible for the Committee to 

 advise the IWC on the effect of the 1982 moratorium 

 decision on the Okhotsk Sea-West Pacific stock of 

 minke whales. 



Regarding future comprehensive assessments, the 

 Scientific Committee recommended, and the IWC 

 agreed to consider, all Southern Hemisphere baleen 

 whales (except minke and right whales) and North 

 Atlantic minke, fin, and sei whales at its 1992 meet- 

 ing. A steering group for baleen whale assessments 

 was established and is scheduled to meet in Copenha- 

 gen on 2-6 March 1992. 



Revised Management Procedure — As noted 

 above, the 1982 moratorium provision called upon the 

 IWC to undertake a comprehensive assessment of the 

 effects of the whaling moratorium on whale stocks. 

 The IWC subsequently agreed with a recommendation 

 of its Scientific Conunittee that this should include an 

 examination of alternatives to its management proce- 

 dure for calculating whaling quotas. The Scientific 

 Conmiittee began developing a revised management 

 procedure and assessing candidate procedures during 

 a series of workshops and special meetings beginning 

 in 1989. 



The Committee reviewed results of the December 

 1990 workshop in Tokyo and, at its 1991 meeting, it 

 reconunended adoption of a single-stock management 

 procedure developed by J. Cooke. Based on an 

 assumption that long-term management of a population 

 should not allow it to be reduced below 72 percent of 

 the stock's carrying capacity or pre-exploitation size, 

 the procedure would: (1) establish catch limits of 

 zero for stocks found to be below 54 percent of their 

 carrying capacity size, and (2) reduce catch limits 

 from maximum level, when the stock is at its carrying 

 capacity size, to zero, as a stock approaches 54 

 percent of its carrying capacity size. 



The IWC subsequently adopted by resolution the 

 recommended single-stock procedure. As a related 

 matter, the resolution also requested the Scientific 

 Committee to address the development of a multi- 

 stock management procedure and provide advice on 

 the minimum standards for data, including coverage 

 and methodology for sighting surveys, analytical tech- 



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