Chapter n — Species of Special Concern 



the Government of Canada under the Pelly Amend- 

 ment for diminishing the effectiveness of the IWC's 

 conservation program. At the end of 1991, the 

 United States was continuing informal discussions 

 with representatives of the Canadian Government, and 

 no action had been taken on the recommendation. 



Industry /Native Agreement 



Seismic surveys and other activities associated with 

 offshore oil and gas exploration and development may 

 affect the movement and behavior of bowhead whales 

 during their migrations. These in turn may affect the 

 Alaska Eskimo spring and fall bowhead whale hunts 

 as well as the whales themselves. Hunters may have 

 to travel greater distances to find whales, thereby 

 increasing die risk that they may be injured or killed 

 or unable to bring the whales killed back to their 

 villages. To avoid such possibilities, the Alaska 

 Eskimo Whaling Commission and certain oil compa- 

 nies engaged in activities on Alaska's North Slope 

 entered into a cooperative agreement in 1986 calling 

 upon the industry to assist with towing whales killed 

 by Native hunters to a suitable butchering site to 

 prevent meat from spoiling; cache emergency sup- 

 plies, such as gasoline and food, at selected sites for 

 use by Native subsistence hunters; provide emergency 

 assistance to hunters during adverse weather condi- 

 tions; assist with the transport of whale meat and 

 muktuk to prevent spoilage and maximize utilization; 

 and specify actions that industry planes and vessels 

 would take to avoid interfering with ongoing whaling 

 activity. The agreement was approved by the Nation- 

 al Oceanic and Atmospheric Administration and has 

 been renewed annually. 



Current Population Status 



In May 1991, the IWC's Scientific Committee 

 undertook a comprehensive assessment of the western 

 Arctic bowhead whale population. The Committee 

 reviewed the results of recent and ongoing photogram- 

 metric studies, ice-based censuses, subsistence catch- 

 es, and carbon isotope baleen aging studies. In 

 combination, these results provided new information 

 suggesting that: individual growth is slower, and age 

 at first parturition (i.e., female sexual maturity) is 

 later, tiian previously thought (13-17 years instead of 



9 years); age at recruitment into the exploitable 

 population is from 1 to 7 years; the average calving 

 interval is probablyb about 4 years; the proportion of 

 immature animals in the population is 0.44 to 0.65, 

 which is indicative of a recovering population; and the 

 net rate of population increase for the period 1978 to 

 1988 was 3.1 percent per year. 



The Scientific Committee estimated that, in 1988, 

 the western Arctic bowhead whale population num- 

 bered approximately 7,500 animals (95 percent 

 confidence interval of 6,400 to 9,200 animals). The 

 initial pre-exploitation (1848) population was estimat- 

 ed to have numbered 12,400 to 18,200 animals. 

 Although the Scientific Committee was unable to 

 define the maximum sustainable yield (MSY) level, it 

 concluded that the current depletion level (cur- 

 rent/historic population size) is likely between 0.44 

 and 0.65 and that the stock, therefore, may be closer 

 to its MSY level than previously thought. In addition, 

 the Scientific Committee estimated that from 1978 to 

 1988, the population increased at an average of 3.1 

 percent per year (95 percent confidence interval 0. 1 to 

 6. 1 percent per year). 



Assuming no dramatic changes in the environment 

 or in the age composition of the catch, the Scientific 

 Committee estimated that the annual replacement yield 

 (i.e., the number of animals that could be replaced by 

 population growth if taken from this population) 

 would be 254, with 92 whales being the lower bound 

 of the estimate's 95 percent confidence interval. The 

 Scientific Committee concluded that the expected 

 Native subsistence kills of 41 to 54 whales per year, 

 by themselves, should not prevent recovery of this 

 stock. It noted, however, that other factors (e.g., 

 environmental change, pollution, noise disturbance 

 from offshore oil and gas resource development, etc.), 

 combined with the subsistence take, could have 

 cumulative effects that might prevent or delay the 

 stock's recovery. 



The Scientific Committee noted that the distribution 

 and known feeding areas of the western Arctic bow- 

 head whale population include areas that have been, 

 and are likely to be, leased for oil, gas, and other 

 mineral resource exploration and development. 

 Although a great deal of research has been undertaken 

 to identify and assess the possible effects of such 



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