FARMING AND PHYSIOLOGY OF THE RED ALGAE EUCHEUMA - GROWING COMMERCIALIMPORTANCE IN EAST-AFRICA

Red marine macroalgae of the genus Eucheuma were introduced from the P hilippines to Zanzibar in 1989. Their cultivation is of growing import ance, especially on the islands of Zanzibar and Pemba. The algae are c ultivated for the production of carrageenan, a thickener used in many food products. Dried algae are the major export article of the islands today, This paper describes experiments performed with Eucheuma spp,, mainly E. denticulatum. Problems related to epiphytes and grazers on Eucheuma are discussed, as well as the stress-induced disease ice-ice and the production of hydrogen peroxide. Eucheuma spp. also produce vo latile halogenated compounds which may be part of their chemical defen ce. Good water exchange is of importance since carbon dioxide is the m ain form of inorganic carbon taken up. a potential threat to the culti vation of Eucheuma on Zanzibar is the narrow genetic base.