Professor, Moscow University, since 1930. Corresponding member, USSR Academy of Science, since 1953. Associate, Institute of Oceanography, USSR Academy of Science, since 1947.
Member, Advisory Committee on Marine Science, UNESCO, and V.-President, Special Committee Oceanographic research, International Council of Science Unions, since 1955. Chairman, International Oceanographic Commission, USSR Academy of Science. Bureau member,Department of Geology and Geography Science, USSR Academy of Science, since 1960.
Specialist in marine fauna, taxonomy, comparative anatomy and ecology of vertebrates. Introduced quantitative method for study of marine fauna and deduced important laws of distribution of marine organisms in northern seas of USSR. Also studies evolution of motion and locomotive organs of invertebrate animals.
1916-1930 instructor, Moscow University. 1921-1930 at State Oceanographic Institute, which he helped organize. Member of several expeditions for complex studies of the northern seas, Caspian, Far Eastern seas and Pacific.
1949-1952 headed “Vityaz” expedition. 1959 member, Soviet delegation at 1st International Oceanographic Congress, New York.