Two incidents of Polar Bear predation on Belugas which occurred off the coast of western Alaska in April 1984 are described. A single subadult Beluga was killed at a small lead in the Chukchi Sea, probably by a female bear with three cubs, and at least 40 whales were killed at an ice entrapment by one or more bears in the northern Bering Sea. A review of such occurrences off Alaska, Canada, and Eurasia indicates that Belugas are normal prey of Polar Bears. Bear predation may occur when whales are entrapped by ice or while unrestrained whales are passing through leads or surfacing at holes in deteriorating ice sheets . Bear predation probably has little effect on Beluga populations, although it may be of occasional significance at entrapments when many whales are killed that eventually would have been released. Belugas are large in comparison to other potential prey and may be of some local importance in Polar Bear diets .

Recent observations confirm that Killer Whales (Orcinus orca) occur off the coast of western Alaska from at least Bristol Bay to north of Point Barrow.They have been seen in drifting ice in spring and in open water during summer.Three strandings involving 10 animals that occurred in 1982-1984 in the area from Nunivak Island to Norton Sound are described.Observations of Killer Whales chasing a Minke Whale ( Balaenoptera acutorostrata) aground in Unalaska Bay, and of Killer Whales eating a Gray Whale (Eschrichtius robustus) in the Chukchi Sea are reported.The marine mammal prey of Killer Whales in the area include Gray Whales, Minke Whales, Walruses (Odobenus rosmarus), Beluga Whales ( Delphinapterus leucas), and seals (Phocidae).

A bstract Research was conducted in Bristol Bay, Alaska, to determine the applicability of radiotagging to studies of behavior, distribution and movements of belukha whales. Backpack‐style VHF transmitters were attached to two belukhas by pinning through the dorsal ridge. Both packages were shed after about 2 wk due to migration of the pin through the tissue. Movements of radio‐tagged whales were essentially local within Kvichak Bay. Three basic respiration patterns were identified: surfacings that were grouped into breathing periods separated by longer dives; surfacings that did not occur during restricted breathing periods; and long‐to‐very‐long surfacings separated by short‐to‐very‐short dives. These patterns were interpreted as representing traveling, feeding and feeding or resting in very shallow water. Surface and dive interval data were used to calculate a correction factor of 2.75, which could then be applied to aerial survey counts to estimate the total number of belukha whales in the study area. Modifications to radio packages are necessary in order to increase retention time.

A 2-year study was conducted in Bristol Bay, Alaska, to develop and test techniques for marking belukha whales with visual and radio tags. Information was also gathered on belukha distribution and abundance, foods and feeding, and rates and causes of mortality. Two types of radio packages were developed: an OAR backpack designed to be bolted through the dorsal ridge, and a Telonics barnacle tag with an umbrella-stake attachment. Testing of tags and attachments revealed that the more-powerful OAR radio could be received at longer distances and lower antenna heights, and the the umbrella-stake attachment penetrated too deeply for reliable use on belukhas.