 Zavoyko's reports about the potential importance of the river led to the 1846 expedition to study Amur and ultimately to the incorporation of the modern Primorsky Krai to Russia (see Amur Annexation).In 1850, he was appointed governor of Kamchatka and the commander of the port of Petropavlovsk.Under Zavoyko's governorship, Kamchatka expanded to include a wharf, foundry, and a new army barracks.