Specific features of the spatial and temporal distribution of the White Sea population of harp seal

Analysis of the data obtained during aerial survey of sea mammals in the 1980s–1990s (White and Barents seas) has revealed that, during all the seasons of the year, harp seals of the White Sea population form two types of aggregations which differ in size and some ecological features. Large herds of seals (tens of thousands of individuals) are able to occupy areas extending tens and even hundreds of kilometers. Harp seals prefer to inhabit the northern part of the population range (Barents Sea), whereas the southern part (White Sea) is mainly used for reproduction and molting. Small herds (several hundred animals) can be scattered over vast territories, but they tend to dwell in the southern part of the area including the White Sea and southern areas of the Barents Sea. The opportunity to distinguish between these two types of aggregations makes it possible to study the biological features of each of them and to specify characteristics of the species biology.