Advances in cultivation of Gelidiales

Currently, Gelidium and Pterocladia (Gelidiales) are collected or harvested only from the sea. Despite several attempts to develop a cultivation technology for Gelidium, no successful methodology has yet been developed. Initial steps towards developmental efforts in Portugal, Spain, South Africa and Israel have been published. More developments have probably been performed but have not been published. Two different technological concepts have been tested for Gelidium cultivation: (1) the attachment of Gelidium fragments to concrete cylinders floating in the sea, and (2) free-floating pond cultivation technology. These vegetative cultivation technologies might be partially optimized by controlling physical, chemical and biological growth factors. The pond cultivation technology is the much more controllable option. The effects of all factors are discussed in detail in this review. It seems that the main difficulty with cultivation of Gelidium is its low growth rate. The claimed yields of the two technologies are far from being economically attractive at this stage of their development. It seems that in order to introduce Gelidium into commercial cultivation, major efforts in genetic improvement through selection or genetic engineering will be required. Only high yield strains will have the potential to compete economically with the present harvesting tradition. However, accumulated experience with genetic improvement of other useful seaweed species suggests that this is possible.