Return of the dugong, seaweed farming & oysters' charm

We're plunging into the oceans this week on Living Planet with stories of algae, bivalves and dugongs! Seaweed farmers in Zanzibar are adapting to climate change while Indian fishermen are facilitating one marine mammal's comeback. And mussels, clams and oysters contain mind-boggling secret uses — from cleaning waterways to providing low-carbon building materials.