Educational film about the biological and mineral resources of the seas of the Soviet Union. Bird colonies of the Arctic Ocean, walruses. Dolphins are playing in the Black Sea, schools of fish are swimming. In the Black Sea, in addition to fishing, they are engaged in the extraction of algae, from which agaroid is obtained at the plant in Odessa. On the islands of the Far East seal rookery, sea lions jump from a cliff into the sea. Sea otters swim in the waters of the Commander Islands. The city of Shevchenko (present-day Aktau) in the Kazakh desert has turned into an oasis thanks to a seawater desalination plant, residents do not lack water. The Kislogubskaya power plant in the Murmansk region operates using the power of the ebb and flow of sea water. Oil is being extracted on the shelf of the Caspian Sea. Artificial fish farming is shown. The inhabitants of our country travel both in the warm and in the northern seas.