It is known that both the Soviet Union and the USA had programs for using dolphins, seals, and sea lions for military tasks, such as detecting underwater mines or neutralizing scuba divers. However, the first experiments in this field began back in the Russian Empire in 1915. At that time, the famous trainer Vladimir Durov approached the General Staff of the Navy with a proposal to train seals to search for mines. Twenty animals were prepared, but one day they were all poisoned, presumably by German intelligence.