gh SEALS OF THREE SEAS

The ringed seal (Phoca hispida) is one of the most numerous and widespread seal species. In Russia, they populate the Baltic Sea, northern and far-east seas and Ladoga Lake. The ringed seal has a close relative - the Baikal seal (Phoca sibirica), which can be found only in Lake Baikal and sometimes in the Angara and Selenga Rivers where they sometimes intrude from the lake. The fate of these animals differs in all these areas. In Ladoga Lake, the seal population decreased drastically in the 20s-30s of the 20th century and the subspecies was recorded among specially protected animals, but in the North, according to the findings of the research undertaken by G.N. Ognetov from the Northern Branch of the Polar Research Institute of Maritime Fish Industry and Oceanography, the number of ringed seals has not changed within the last twenty-five years.

The first attempts to count northern seals were undertaken by Soviet researchers back in the 60s. It seemed that the area from Novaya Zemlya (New Land) through Bering Strait was populated by numerous seals, the total number exceeding two million. The number of seals inhabiting the areas westbound from Novaya Zamlya (New Land) and the Kara Sea was unclear for a long time. Early in the 60s, the calculation made from the airplane proved that there were few seals in the Barents Sea, and the researchers managed to count only twenty thousand animals along the Novaya Zemlya (New Land) coast. In mid-90s, the seal population was estimated already as 50 thousand. Nevertheless, quite a different estimate - 250-500 thousand - was made at the very end of the 20th century.

Counting seal population is quite uneasy. For example, the Kara Sea is covered with ice for the major part of the year and it is practically impossible to count the population of seals living there. The researchers investigate the area on board of ice-breakers. In the White Sea, the seals are counted both from ships and airplanes. This seal population was studied rather well, the researchers even managed to monitor the quantity dynamics. The quantity turned out to change significantly within the last twenty-five years, varying from ten through thirty thousand. The lowest quantity of the White Sea seals was recorded in 1988, and the highest - in 1993. The current estimate states that the seals population in the White Sea makes approximately 20 thousand. In the Barents Sea, the seals are counted from airplanes in springtime when the seals accumulate in crowds and start reproducing on drift-ice and fast ice. In the researchers' opinion, about half of the animals can be seen at each point of time, while the rest swim in the sea searching for food. To estimate the overall quantity, the researchers have to find out the number of animals per square kilometer and to calculate the square of the ice occupied by the seals.

As the scientists have learned from aeronautical research, one seal accounts for seven to ten square kilometers. Consequently, the Barents Sea is populated by 90-150 thousand seals. So, only three northern seas of Russia taken together are inhabited by approximately 220 thousand seals. About the same quantity was counted in mid-70s. However, the researchers from the Murmansk Maritime Biological Institute, Scientific Center, Russian Academy of Sciences, who investigated the relationships between the seals and the polar bears, counted 90-150 thousand seals and more than 3 thousand bears feeding on the seals in the Kara Sea. Taking this estimate into account, the total quantity of seals in the three seas can rise even up to 300 thousand.

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