Seaweed resources of Tanzania: status, potential species, challenges and development potentials

Tanzania is endowed with a rich biodiversity of seaweed species that grow naturally in its oligotrophic waters of the Western Indian Ocean. Most of these species are unexploited. Only two red seaweeds Eucheuma and Kappaphycus have been studied for commercial farming and the industrial production is based on these species. Another genus of red seaweed, Gracilaria, has been studied and experimented upon for potential farming while others such as the green Ulva, the red Hypnea and the brown Sargassum have been mentioned as potential species for farming. Farming technology used to cultivate the two commercial species is the shallow water off-bottom technology which is badly affected by the increase in surface seawater temperatures (climate change), causing massive die-backs and decreased seaweed production. Some deeper-water farming technologies have been developed but only tubular nets show promise and have been piloted. A number of opportunities exist in seaweed farming, which can be used to advance the industry. The future of the seaweed industry in Tanzania will depend on using the existing opportunities, including utilising the seaweed species already studied, exploring the potential of other seaweed species for farming, development of deeper-water farming technologies, added-value, and ensuring availability of good quality seed material.