Agricultural potential is high, particularly in the fertile northern regions, which accounts for the bulk of the country's agricultural surplus. The main cash crops are sugar, copra, cashew nuts, tea, and tobacco. Total sugar production was expected to rise by 160% in the 2000s, which would make the country a major net exporter for the first time since independence. All the plantations and refineries have been privatized. Marine products, particularly prawns, are Mozambique's largest single export. There is an abundance of marine resources that are not fully exploited. After the Mozambican Civil War, the return of internally displaced persons and the gradual restoration of rural markets have enabled Mozambique to increase agricultural production dramatically.