The province of Bali was the first place where extensive commercial seaweed farming began in Indonesia about thirty years ago. Since then the cultivation and processing of seaweeds has become a significant industry that provides income for tens of thousands of people in coastal communities throughout the country. Currently the Indonesian seaweed industry is primarily based on seaweeds that serve as raw material for carrageenans and agars. Although a processing industry has developed in Indonesia, most cultivated seaweeds are still exported as raw, dried seaweeds. With its vast geographic, natural and human resources there is tremendous scope for diversification and expansion of seaweed-based industries in Indonesia. In order to make that happen it is necessary to mobilize “seaweed science for sustainable prosperity” and that is the theme for the 21st International Seaweed Symposium.