Effect of dense stocking of Gracilaria sp on growth and survival of milkfish (Chanos chanos forskal) on polyculture culture systems

Milkfish cultivation has long been recognized by farmers and is now developing in almost all Indonesian waters. Fish culture technology is also experiencing rapid development, ranging from traditional maintenance to intensive technology that requires seed, water, and planned feed management. One way to fill the empty ecological space is to cultivate a mixture (polyculture) between several fisheries commodities. With this system, the benefits obtained are high land productivity. The development of aquaculture technology shows that milkfish (Chanos chanos Forskal) can be cultivated together with Gracilaria sp. Seaweed in a pond. This polyculture system can increase the efficiency of land use and farmers' income in a sustainable manner. The study was conducted using the experimental method. The density of gracilaria sp distribution in this study was: treatment A (nongracilaria), treatment B (gracilaria 50 Kg), treatment C (gracilaria 100 Kg), treatment D (gracilaria 150 Kg) and Treatment E (gracilaria 200 Kg). The design used was a completely randomized design (CRD) with 5 treatments and 3 replications. The main parameters observed were growth including absolute length, absolute weight, specific growth rate, and survival. As supporting data the measurement of water quality is also carried out.