MARINE MAMMAL COMMISSION — Annual Report for 1992 
under the Pelly Amendment for diminishing the 
effectiveness of the IWC’s conservation program. No 
action was taken in 1991 or 1992 to certify Canada 
for authorizing the whaling activities. However, 
representatives of the Canadian Government were 
contacted to determine Canada’s intent concerning 
future bowhead whale hunting and the possibility of 
rejoining the IWC. No bowhead whales were taken, 
or authorized to be taken, by the Inuvialuit in 1992, 
and no action was taken by the Canadian Government 
to join the IWC. 
Industry/Native Agreement 
Various activities associated with offshore oil and 
gas exploration and development may affect the 
movement and behavior of bowhead whales, which 
may in turn affect the Alaska Eskimo bowhead whale 
hunts. For example, hunters may have to travel 
greater distances to find whales, thereby increasing 
their risk of being injured or killed. To avoid such 
possibilities, the Alaska Eskimo Whaling Commission 
and certain oil companies engaged in activities on 
Alaska’s North Slope entered into a cooperative 
agreement calling upon the industry to assist Native 
hunters, as needed, in a number of ways. These may 
include towing whales killed by Native hunters to a 
suitable butchering site to prevent meat from spoiling; 
caching emergency supplies, such as gasoline and 
food, at selected sites for use by Native subsistence 
hunters; providing emergency assistance to hunters 
during adverse weather conditions; assisting with the 
transport of whale meat to minimize spoilage; and 
specifying actions that industry planes and vessels will 
take to avoid interfering with ongoing whaling activi- 
ty. The agreement was approved by the National 
Oceanic and Atmospheric Administration in 1986 and 
has been renewed annually since that time. 
Current Population Status 
In May 1991 the IWC’s Scientific Committee 
conducted a comprehensive assessment of the western 
Arctic bowhead whale population. The Committee 
reviewed the results of recent and ongoing photo- 
grammetry studies, ice-based censuses, subsistence 
catches, and other population studies. In combination, 
these research results provide new insight into the 
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population biology of bowhead whales. They suggest 
that individual growth is slower and age of onset of 
female sexual maturity is later (13-17 years instead of 
9 years) than previously thought; age at recruitment of 
whales into the exploitable population is between 1 to 
7 years; the average calving interval is probably about 
4 years; the proportion of immature individuals in the 
population is 0.44 to 0.65, which is indicative of a 
growing population; and the population increased at 
an average annual rate of 3.1 percent for the period 
1978 to 1988. 
The Committee estimated that in 1988 the western 
Arctic bowhead whale population numbered approxi- 
mately 7,500 animals (95 percent confidence interval 
of 6,400 to 9,200 animals). The initial pre-exploita- 
tion (1848) population was estimated at 12,400 to 
18,200 whales. The Committee also estimated that 
the annual replacement yield (i.e., the number of 
animals that could be replaced by population growth 
if taken from the population) would be 254 individu- 
als, with 92 whales being the lower bound of the 
estimate’s 95 percent confidence interval. The 
Committee concluded that the expected Native subsis- 
tence kills of 41 to 54 whales per year, by them- 
selves, should not prevent the recovery of the stock. 
However, other factors (e.g., environmental change, 
pollution, noise disturbance from offshore oil and gas 
resource development, efc.), combined with the 
subsistence take, could have cumulative effects that 
would prevent the stock’s recovery. 
Attempts to undertake simultaneous ice edge visual 
and acoustic censuses and aerial surveys were unsuc- 
cessful in 1992 due to severe ice conditions, but it is 
planned that these studies will be conducted in 1993. 
With the 1993 data, the Scientific Committee hopes to 
make a new assessment of the stock in 1994. 
Research Planning and Coordination 
As noted in previous annual reports, the Marine 
Mammal Commission has played a significant role in 
planning and coordinating U.S. bowhead whale 
research. Between 1978 and 1981, the Commission 
recommended and helped organize research review 
and coordination meetings. The meetings were 
designed to identify and avoid possible duplication of 
research and to coordinate work being planned or 
