Zanzibar's seaweed growers face a changing climate. Here, a farmer tends to her farm in Paje, on the southeast coast of the island.
Mwanaisha Makame and Mashavu Rum, who have been farming seaweed on beautiful Zanzibar island for 20 years, wade through the low tide to their farm.
The seaweed grows underwater for 45 days. When it reaches one kilogram, the women pick it and dry it, then pack it in bags to be exported to countries like China, Korea and Vietnam. There, it's used in medicines and shampoos.
The farmers have a lot of problems due to climate change. Two decades ago, 450 seaweed farmers roamed Paje. Now, only about 150 farmers remain.
Mwanaisha holds up a healthy clump of seaweed. Then she holds up seaweed the farmers won't be able to use. A hard white substance grows on it - ice-ice disease, caused by higher ocean temperatures and intense sunlight.
The seaweed farmers learned how to make soap from their seaweed at the Zanzibar Seaweed Center, a business that started as an NGO in 2009. At their homes, they mix water, ground seaweed powder, coconut oil, caustic soda and essential oils in a large plastic tub.
Later in the week, the seaweed farmers will sell their finished soaps in Zanzibar town or to regular local customers. As seaweed levels decline, they have found a way to increase the value of their work.