In 1979- 1981 at the King George Island samples of adipose tissue of 5 pinniped species (L. carcinophagus, L. weddelli, H. leptonyx, M. leonina and A. gazella) were collected and the contents of chlorinated hydrocarbons (CHs) were determined with the gas chromatography method. The highest values were recorded in the leopard seal (432.3 -614.7 ppb DDT), the second highest values in the mature elephant seal (73.4 ppb DDT) and the third in the Weddell seal (54.4 — 69.1 ppb DDT). In the Weddell seal the highest level of HCH content (23.3 — 32.1 ppb) was recorded. A decrease in the content of pp'DDE in the adipose tissue of crabeater seal in successive years was recorded, the values being 36.8 ppb in 1979, 24.4 ppb in 1980 and 15.3 ppb in 1981, as well as an increase in the concentration of HCH (15.3 ppb in 1980 and 27.4 ppb in 1981). The contents of CHs in the adipose tissue of Antarctic pinnipeds are 100—1000 times lower than those in the Arctic seals.

Distribution and numbers of Lobodon carcinophagus and Leptonychotes weddelli were evaluated. Lobodon carcinophagus dominated on ice floes in offshore zone of Mirnyj Station and in regions of open pack ice close to the northern edge of ice fields. Leptonychotes weddelli dominated only on the shore-ice close to Leningradskaja Station in March 1979. A thesis of the lowered daily activity of Leptonychotes weddelli was confirmed by observations.

Pinnipeds were monitored in Admiralty Bay between 1988 and 1992. No particular trends during this period were found, but seasonal changes in each are distinct. It is suggested that the phenology of pinnipeds and that of penguins ensures low competition for food between these groups.

On the basis of observations and markings of Weddell seals in the region of the Admiralty Bay it was estimated that numbers of this species decreased systematically from about 500 to about 100 individuals from December to February. The sex structure of the local population also changed, showing a growing domination of females. Males were observed more often on coastal snow patches, females prevailed on rocky beaches close to the sea. A thesis of an increased nocturnal activity of Weddell seal was confirmed, indicating also a possibility of a two days activity cycle of this species. Synchronized among the individuals of local populations by atmoshperic conditionds.