IMPROVEMENT QUALITY OF BRACKISH WATERS THROUGH SEAWEED SCENARIO MODEL OF GRACILARIA SP. AS BIOFILTER AGENT

Development of aquaculture, especially shrimp brackish in coastal areas will greatly affect the quality of the coastal environment. Mistakes in the management of shrimp culture will lead to a decrease in environmental quality that will threaten the sustainability of coastal resources and ultimately endanger the continuity of cultivation. Decreasing the feasibility of aquatic quality as a result of disposal of cultivated waste operations can affect the life of shrimp that is cultivated can even lead to crop failure and declining productivity function of cultivated land. This research was conducted in coastal area of Brebes Sub-district, Brebes Regency. The method used in the research is direct survey in the field to obtain primary data. The results of this study showed that the presence of seaweed biofilter showed an increase in water conditions and ponds located in coastal areas of Brebes. Seaweed biofilter gives the result of absorption of Nitrogen (N) content of 0.08%, phosphorus content of 0.01% and organic C content absorbed in seaweed by 0.07%. Improving the quality of pond waters with the existence of seaweed cultivation makes a difference the organic matter content of elements of N and P compared with those not planted with seaweed. It can be seen from organic matter content, N and P is 112,72% for organic material, 0,34% for N and P equal to 0,02% for brackhishs planted with seaweed, while in brackhish not planted with seaweed material organic content of 106.20%, 0.32% for Nitrogen and 0.01% for P. During the study of water quality included in the category appropriate for aquaculture. Simulation results and model scenarios with increasing biofilter coefficients show significant rates of cultivation waste reduction accompanied by an increase in farmer's income.