Seaweed fishing has long provided a decent livelihood on Zanzibar, an archipelago of islands off Tanzania. During lower tides, seaweed farmers wear traditional Swahili dress as they harvest, half-submerged in the blue-green water. Most of the farmers are women.

The commercial-grade seaweed has many uses, from toothpaste to food additive. However local fishers complain that the water is slowly warming resulting in less and less seaweed. Last year, they lost four tons of seaweed due to warmer weather.

The possible effects of climate change are just one of many problems facing the coastal communities of Zanzibar, known for its rich melding of cultures, lush marine ecosystem and majestic coral reefs. For centuries, coastal dwellers have based their livelihoods on marine and coastal resources.

The fisher village of Kizimkazi is emblematic of this reliance on the South West Indian Ocean. It is a fishing hub for villagers, which falls within the Menai Bay Conservation Area, a protected ecosystem busy with sea turtles, coral reefs, bottlenose dolphins and tourists.

One resident of Kizimkazi, 70-year-old Amina Taku, is on her feet at dawn to catch the high tide and collect shellfish to sell to hotels. She and other fishers who have been working since the 1970s say they have observed diminished returns as the catch size and the amount of fish wanes.

“I have been fishing since 1973,” said Shaaban Foum Haji. “We used to have a lot of fish, but today we can go fishing for two days and come back empty-handed, with nothing or just enough to pay the fuel cost.”