The economy of Zanzibar island is almost exclusively agricultural; fertile soil is limited to the western half of the island. The chief commodities produced are cassava, sweet potatoes, rice, corn, plantains, citrus fruit, cloves (also on Pemba), coconuts, and cacao. There is a sizable fishing industry. The island's few manufactures include clove oil and woven goods. Artisans make objects of wood, ivory, and metal. Lime is the only mineral resource. The main imports are foodstuffs and fuel; the principal exports are cloves and copra.