Every year more slaves were required in East Africa for several reasons: 1. New clove and coconut plantations in Zanzibar and date plantations in Oman needed labor. 2. New farms in the interior of East Africa for production of food crops around inland centers along the caravan routes needed labor.3. More slaves were needed as porters to carry trade goods from the coast to the interior, and ivory and other products from the interior to the coast. 4. Brazilian traders, to avoid the British navy intercepting their slave ships in West Africa, had started obtaining slaves from the Portuguese in Angola, the Zambezi valley and the coast of Mozambique. 5. The French needed cheap labor on their newly started sugar and coffee plantations in the islands of Mauritius, Seychelles, Reunion, Rodrigues and southern Madagascar. 6. Many male slaves in Zanzibar and Mombasa would become free after some years in servitude, older slaves would retire or die, and new ships and businesses, building and 3construction work needed new slaves.