Developments in production technology of Kappaphycus in the Philippines: more than four decades of farming

Kappaphycus is one of the most significant, economically valuable red seaweeds, cultivated in tropical and subtropical waters. This alga demands a relatively high market value globally, due to applications of the kappa carrageenan colloid that is industrially extracted from the biomass. Carrageenan is widely used in food, pharmaceuticals, and nutraceuticals and for aquaculture applications. The first successful commercial cultivation of Kappaphycus (previously called Eucheuma) was recorded from the southern Philippines in the late 1960s using the line and stake method. Dramatic production increases were achieved, with the Philippines being the leading producer of Kappaphycus for more than 30 years, until it was overtaken by Indonesia (in approximately 2008). By 1988, Kappaphycus farming became widespread in Indonesia, and efforts have been undertaken to spread Kappaphycus farming to more than 30 countries worldwide. Since 2008 Kappaphycus production steadily rose in Indonesia, but production from the Philippines has tended to decline since 2011. Research and development (R&D) initiatives focusing on Kappaphycus in the Philippines emphasized the means to increase productivity and solutions to issues causing declining production. R&D focusing on Kappaphycus cultivars in the Philippines was made through the National Seaweed R&D Program. Several institutions and research centers took major steps to achieve these objectives. There were significant and relevant results obtained in studies of molecular taxonomy, factors affecting sporulation, tissue culture and mutagenesis, protoplast isolation, strain selection, mitigation of ‘ice–ice’ malaise and Neosiphonia infestations. A recent development in Kappaphycus farming was the discovery that use of an extract from a brown seaweed acts as a biostimulant to improve tolerance of cultivars to abiotic stresses. Problems and challenges encountered in the production of Kappaphycus, even after more than 40 years of farming, but which needed to be overcome, are discussed.