Water quality changes in the coastal area of intensive whiteleg shrimp brackish water pond aquaculture

Whiteleg shrimp (Litopenaeus vannamei) culture with more advanced technology has been developed in the coastal regions of Southeast Asia, including Indonesia, to catch up with the increasing worldwide demand for shrimp. If left unchecked, the effluent from this high-density shrimp farming could have irreversible impacts on the receiving environment and the shrimp industry. This study was carried out to determine changes in water quality status before and post-development of the intensive whiteleg shrimp industry in the coastal area of Je’neponto, a regency located in the south of South Sulawesi Province, Indonesia. The water quality parameters were measured in situ and ex situ before the farming cycle started and after harvesting. Temperature, salinity, pH, dissolved oxygen, nitrate, nitrite, ammonia, and phosphate were measured using standardised methods. The data were statistically analysed using Kruskal–Wallis, Mann–Whitney, and principal component analysis. Water quality status was determined using the storage and retrieval approach. The potential for waste from the intensive whiteleg shrimp ponds was estimated at 7,408 kg of total nitrogen (TN) per cycle and 1,748 kg of total phosphorus (TP) per cycle. The study also found that the wastewater treatment plant pond was only about 1.45% of the total pond volume and is classified as a low-capacity wastewater treatment plant for intensive whiteleg shrimp farming. The water quality was classified in the class B category (good or slightly polluted) prior to the operation of the shrimp farm to class C (moderate or moderately polluted) afterwards.