In 1932–1936, Pyotr Shirshov was employed as a researcher at the All-Union Arctic Institute.

He participated in numerous Arctic expeditions, including the ones on icebreakers Sibiryakov (1932) and Chelyuskin and a drifting ice station North Pole-1 (1937-1938).

Pyotr Shirshov authored numerous works dealing with his research on plankton in polar regions.

He is known to have proven the fallacy of the hypothesis that there is no life in high latitudes of the Arctic Ocean.

This article includes content derived from the Great Soviet Encyclopedia, 1969–1978, which is partially in the public domain.