The Saprobic Index for Water Quality Based on Fish Aquaculture: A Case Study of White Snapper (Lates calcarifer) in Floating Net Cages at Sendang Biru Water, Indonesia

The impact of water organic pollution from leftover fish feed and metabolic waste in floating net cages (FNC) aquaculture can lead to detrimental effects on coastal marine biota. This underscores the necessity for continuous monitoring of water quality in areas surrounding FNCs to mitigate the environmental impacts of aquaculture. One method of evaluating water quality is through the Saprobic Index, which quantitatively analyzes pollution status based on the presence and composition of various organisms, including plankton. This study aims to evaluate the organic pollution potential derived from fish feed in the vicinity of the FNCs at Sendang Biru waters by employing the Saprobic Index. The research identified five classes of phytoplankton in the FNC area: Bacillariophyceae, Dinophyceae, Chrysophyceae, Cyanophyceae, and Globothalamea. Analysis of the phytoplankton composition indicated that the waters surrounding Sendang Biru FNC can be classified as ranging from Oligosaprobic to β-Meso/Oligosaprobic. These findings suggest that the aquaculture practices utilizing the FNC system contribute to a light level of organic pollution in the water. This emphasizes the importance of effective management and monitoring strategies to minimize the environmental impact and ensure the sustainability of aquaculture in coastal marine ecosystems.