Water Quality Assessment Based on Meiofauna Diversity and Phosphate-Nitrate Distribution on the Losari Coast, Indonesia

Various anthropogenic activities in the Losari coastal area, Indonesia, generate and introduce waste by-products into the waters that can harm the surrounding organisms and ecosystems. This study aimed to assess water quality based on meiofauna diversity index and phosphate-nitrate content distribution along the coast, and then examine the relationship between the two pollution indicators. The study was conducted on Losari Coast, Makassar, Indonesia, with nine observation stations representing the objectives of the study. The observation stations are busy areas and there are many anthropogenic activities that have the potential to produce pollutants that will enter the water body. The observation samples were taken purposively, and the data collected were analyzed in a quantitative descriptive study. Ecological analysis was used to analyze biological parameters, while physico-chemical parameters of the aquatic environment were analyzed in situ and ex situ. Principal Component Analysis (PCA) was used to identify the correlation between phosphate-nitrate distribution and its effect on meifauna diversity on Losari Coast. With very low diversity index values, the coastal waters were classified as heavily polluted. Some species of meiofauna, especially those adaptable to such environments, were present in high abundance. The phosphate and nitrate contents exceeded the upper limit set by the government for the maximum allowable presence in coastal waters. Therefore, the area is at risk of eutrophication characterized by algae, algae and phytoplankton blooms that block sunlight from reaching underwater plants, causing dissolved oxygen depletion and death of various aquatic organisms. Phosphate levels were positively correlated and strongly influenced the diversity of local meiofauna, while the opposite was true for nitrate: it was negatively correlated and the effect was weak.