Small patches of indigenous forest and isolated large trees support the view that much of the island was originally covered by dense evergreen forest. The open coral-outcrop country supports dense thicket vegetation. The flat clay plains are grass-covered. The major wild animals include leopard (a variety peculiar to Zanzibar), civet cat, mongoose, two species of monkey, lemur, the African pig, forest duiker, pigmy antelope, about 20 species of bats, and 30 forms of snakes.
Before the development of eastern African mainland ports, Zanzibar was the trade focus of the region and enjoyed an important entrepôt trade. The island’s economy now depends on agriculture and fishing. Considerable areas of fertile soil and a favourable climate enable the production of a variety of tropical crops, most importantly cloves and coconuts. Local food crops, such as rice, cassava, yams, and tropical fruit, are also important. Fish is an important part of the diet, and local fisheries employ perhaps about one-tenth of the population.
The southern and eastern portions of Zanzibar Island have been mainly populated by Bantu-speaking people known as the Hadimu. The northern portion of Zanzibar Island and the adjacent Tumbatu Island have been occupied by another Bantu-speaking people known as the Tumbatu. These two groups represent the earliest arrivals in Zanzibar. Throughout the 19th century, and after, they were expropriated from the western and more fertile parts of the island by later arrivals, notably Arabs. The nationalization of land in 1964, however, was followed by economic reforms that redistributed the land. Fishing has traditionally been highly important in coastal villages and remains so.
According to britannica.com