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Abstract
Basic knowledge of the population biology of Atlantic walruses throughout the eastern parts of their range, including the Pechora Sea, is scarce or nonexistent. Herein, we present the first estimate of walrus numbers from the Pechora Sea based on an aerial survey of 2,563 km of coastline, using a combination of infrared techniques and digital imagery. Hauled out walruses were found at three sites (Vaygach Island and two sites on Matveyev Island). A total of 968 animals were counted on aerial photographs; all of the animals appeared to be males. Crude measurements of dorsal curvilinear lengths of a subset of the photographed animals (N = 504) showed that many were adults, but 14.5 % belonged to younger age classes (shorter than 225 cm). Using an adjustment factor developed for male walruses in Svalbard, to account for animals at sea during the survey, the number of walruses occupying this area was estimated to be 3,943 (95 % CI, 3,605-4,325). No females with calves were seen in this survey, implying that the population that uses the Pechora Sea during summer has a distributional area that is larger than the survey area. Extensive oil exploration, development and production are currently taking place in the Pechora Sea. Risks posed to walruses and their prey by these industrial activities should be assessed immediately, and the genetic delineations of this population should be clarified.[PUBLICATION ABSTRACT]