Bowhead Whale Monitoring Study In The Southeast Beaufort Sea July September 1984 Microform

This study examines the spatial distribution, relative abundance, and age segregation of bowhead whales in relation to petroleum industry activities and oceanographic features in the south-east Beaufort Sea during the 1985 open water season. Surface oceanographic conditions at the time of the aerial surveys (August-September) are described using satellite imagery analyses and in-situ temperature and wind data from industry vessels. Aerial photographic surveys provided information on the age/size class distribution and site tenacity of bowhead whales within the study area. Bowhead sightings recorded by other researchers working in that area during 1985 are also examined. Comparisons are made with results of previous bowhead whale surveys in the area.

The bowhead whale is a large, baleen whale found only in Arctic and sub-Artic waters. It is now one of the rarest cetaceans and is currently considered an endangered species. During August and September whales are present in areas of offshore oil exploration activity in the southeast Beaufort Sea. Aerial systematic and photogrammetric surveys were conducted in the southeast Beaufort Sea during August and September 1986, to investigate the distribution, relative abundance, and age segregation of the whales in relation to petroleum activites in the region. Two systematic surveys of the study area were completed from August 25-September 1 and September 7-14. Photogrammetric surveys of portions of the study area were conducted from August 25-September 1. Bowhead sightings recorded by researchers and by industry personnel during 1986 were also examined.

Systematic aerial surveys were conducted in the southeast Beaufort Sea on 19-24 August and 6-11 September 1983 to document the numbers and distributions of bowhead whales and of other marine mammals. The study area extended from 141 W (Alaska-Yukon border) eastward to 128 40 W (near Cape Bathurst), and from the 2 m depth contour northward to about 25 km north of the 100 m depth contour, except between 141 W and 138 W where the northern boundary was at 70 20 N. The northernmost 25 km sections east of 138 W also extended beyond the 200 m depth contour, and thus included the steep shelf break beyond the shallow continental shelf.

Aerial surveys of the summertime distribution of bowhead whales in the southeastern Beaufort Sea have shown that the distribution of bowheads has been quite variable over the four years of study, 1980-83. This report presents the results of an investigation of the relationship between the observed distribution of bowhead whales in the Canadian Beaufort Sea and the physical and meteorological patterns that might affect the distribution of zooplankton in the Beaufort Sea. The overall aim of this study was to identify easily-monitored parameters that could be used to predict bowhead whale distribution.