wcm.01.2025.165.171

Aquaculture in inland water has the potential to lead to the degradation of the aquatic environment, mainly due to the occurrence of eutrophication. The rise in phosphorus levels can be linked to the excretion of fish and the presence of uneaten feed. The aquatic ecosystem possesses the ability to self-purification and cleanse the phosphorus (P) load. Evaluating the carrying capacity of aquatic environments is essential for the adoption of sustainable aquaculture practices. This study aimed to identify the parameters of aquaculture utilizing a double-layer system, serving as a foundation for assessing the ecological carrying capacity of the Jatigede Reservoir waters for aquaculture activities. From March to May 2021, an evaluation of the aquaculture experiment in Jatiluhur Reservoir was conducted using a double-layer floating net cage (FNC) technique. The fish reared using the double-layer system consisted of common carp in the upper layer and tilapia in the bottom layer. In March, June, and September of 2021, monitoring of water quality parameters in the Jatigede Reservoir was conducted, focusing on total phosphorus, water temperature, pH, and dissolved oxygen. The hydro morphological parameters of the Jatigede Reservoir, specifically area, volume, and water discharge, were analyzed using data from 2018-2020. The weights of the common carp and nile tilapia seeds produced were 13.5 g and 49.0 g, respectively, resulting in total weights of 150 kg and 200 kg. The findings of the study indicated that the FCR value in the double-layer FNC system was 1.61, along with a P load of 18.1 kg P/ton of harvested fish. The findings suggested that the integration of a double layer of FNC might had the potential to enhance the FCR value from 1.71 to 1.61. The utilization of 2,600 kg of feed led to yields of 1,650 kg for common carp and 316 kg for Nile tilapia. The ecological carrying capacity of the double-layer FNC activities in Jatigede Reservoir was measured at 7,207 tons per year, indicating a 22% increase from the single-layer FNC capacity, which stood at 5,482 tons per year.