Results obtained on the changes in growth, reproduction, alginic acid and mannitol contents of Turbinoria decurrens
carried out for one year from March, 1973 to February, 1974 are presented. Young plants of T. decurrens appear in
May and grow to a minimum size between December and February. Branching starts from August and maximum number of branched plants occur in November. Reproductive plants were observed throughout the year. The yield of alginic
acid varies from 16.3 to 26.3 % and the estimated mannitol content from 1.5 to 8.7 %. T. decurrens may be harvested
in the months between December and February for extraction of alginic acid