By Daniel Dickinson BBC News, Pemba, Tanzania
Fatima Hamidi is one of Tanzania's new seaweed farmers.
Seaweed is used in cosmetics, cheese, fertilizer and shampoo. Cultivating her new crop at Vumawimbi beach on the northern tip of Pemba island, Fatima hopes it will supplement the meagre income she earns from other sources. "We don't yet know how successful it will be as we have not sold any yet," says Fatima. "But we think it will help us to earn a little money, which we can invest in other small businesses. We are not rich, sometimes we don't even have the money to buy enough food, so selling seaweed will help." Fatima is one of an estimated 5,000 farmers who are cultivating seaweed on the small island of Pemba.
All along the Tanzanian coast and around its many islands, other farmers are doing the same.
They are meeting a worldwide demand for seaweed, which is being used as an ingredient in everything from cosmetics to cheeses, and fertilizers to shampoos.