PEMBA, an island in the Indian Ocean off the east coast of Africa, forming part of the sultanate of Zanzibar. Pemba lies 30 m. N.N.E. of Zanzibar island between 4° 80' and 5° 30′ S., and 39° 35′ and 39° 50′ E. It is some 40 m. long and 10 across at its broadest part, and has an area of 380 sq. m. It is of coralline formation. On the side facing the mainland the coast is much indented. From its luxuriant vegetation it gets its' Arabic name of Al-huthera—“The Green.” The interior is diversified by hills, some of which exceed 600 ft. The land is chiefly owned by great Arab proprietors, who work their plantations with Swahili labour, and with negroes from the mainland. Prior to 1897 the labourers were all slaves. Their gradual manumission was accomplished without injury to the prosperity of the island. The population is estimated at between 50,000 and 60,000, of whom 2000 to 3000 are Arabs. Most of the inhabitants are of Bantu stock, and are known as Wapemba. In the ports there are many Hindu traders and a few Europeans. The plantations are nearly all devoted to cloves (the annual average output being 10,000,000 ℔) and coco-nut palms (for the preparation of copra). The number of coco-nut plantations is very small compared with those devoted to cloves. Yet cloves need much care and attention and yield small profit, while the coco-nut palm yields a fairly uniform crop of nuts and will grow almost anywhere. The preponderance of clove plantations dates from a cyclone which in 1872 destroyed nearly all the clove-trees in the island of Zanzibar. Thereupon, to benefit from the great rise in the price of cloves, the Pemba planters cut down their palms and planted cloves. The value of the cloves exported in 1907 was £339,000, or 92% of the total exports. India, Germany and Great Britain are, in the order named, the chief purchasers. Other exports include fire-wood, skins and hides, mother-of-pearl, wax and small quantities of rubber, cowries, tortoiseshell and so-called tortoise-nail. The “ tortoise-nail” is the valve with which a shell-fish closes its shell. The Llandolphia rubber-vine is indigenous, and since 1906 Ceara rubber-trees have been extensively planted. Rice, the chief of Pemba’s imports, could easily be grown on the island. Cotton cloths (Kangas) form the next most considerable item in the imports.
Pemba has three ports, all on the west side of the island. Shaki-Shaki, the capital and the centre of trade, is centrally situated at the head of a shallow tidal creek partly blocked by dense growths of mangroves. Mkoani is on the south-west coast, Kishi-Kashi on the north-west coast; at the last-named port there is a deep and well-sheltered harbour, approached however by a narrow and dangerous channel.
Pemba is administered as an integral part of the Zanzibar dominions, and yields a considerable surplus to the exchequer, mainly from a 25% duty imposed on cloves exported. There is a weekly steamship service to Zanzibar, and in 1907 the two islands were connected by wireless telegraphy (see Zanzibar).