Culture potential of Gracilaria salicornia in the brackishwater ecosystem: A multifaceted approach towards sustainable development goals

Abstract Seaweed farming is a sustainable practice that contributes to several of the United Nations' sustainable development goals (SDGs). Cultivation of Gracilaria salicornia , a species of red algae known for its high economic value and ecological benefits. G. salicornia is widely used in various industries, including food, pharmaceuticals and cosmetics, due to its rich content of agar, a gelatinous substance with numerous applications. This study investigated the potential of G. salicornia cultivation in the brackishwater environment using a raft-based system with twelve 3 m 2 rafts, each equipped with twelve 25 mm mesh mono line tube nets. The initial stocking density was set at 1.2 kg of G. salicornia per tube net. The seaweed growth assessment and water samples were assessed at once in 15-day intervals. Results showed a robust initial growth phase, with an average biomass of 5.07 kg per tube net by the 15th DOC, 7.67 kg by the 30th DOC and further increased to 9.09 kg by the 45th DOC. Specific growth rates (SGR) followed a similar trend, with an initial rapid increase followed by a gradual decline, reaching 9.59% d −1 on the 15th DOC and decreasing to 4.50% d −1 by the 45th DOC. This study demonstrated the viability of G. salicornia cultivation in brackishwater environments using raft methods and its potential to provide alternative livelihood opportunities for coastal communities. This study provides valuable data for optimizing G. salicornia cultivation strategies and promoting sustainable seaweed farming practices.