A novel integrated seaweed–shrimp farming system was developed and validated to enhance the productivity, environmental sustainability, and economic resilience of coastal aquaculture. The experiment was carried out in 500 m² HDPE-lined ponds, each stocked with Penaeus vannamei post-larvae (PL12) at a density of 40 individuals/m². Two treatments were implemented: (i) control ponds without seaweed, and (ii) seaweed-integrated ponds, wherein Gracilaria salicornia was stocked at 7.5 kg per monoline tube net across 30 lines per pond. Over a 110-day culture period, the integrated system exhibited significantly superior performance (p<0.05), with shrimp achieving an average body weight of 23.2±1.1 g, feed conversion ratio (FCR) of 1.38, and survival rate exceeding 98%. In contrast, the control ponds yielded shrimp with an average weight of 19.8±0.98 g, FCR of 1.48, and 97% survival. Simultaneously, the integrated ponds produced approximately 1.2 tons of G. salicornia across two harvests, without the application of external feed or fertilizers. The inclusion of seaweed significantly enhanced water quality by assimilating dissolved nutrients, thereby reducing organic load and supporting a more stable and favourable environment for shrimp culture. This integrated farming model offers a sustainable alternative to conventional monoculture, providing synergistic benefits in terms of improved shrimp growth, health and survival, environmental remediation, and an additional revenue stream through seaweed biomass, thus supporting ecosystem-based and economically viable coastal aquaculture.
Keywords: Gracilaria salicornia, Peneus vannamei, integration, additional revenue.