Studi Cemaran Mikroplastik pada Ikan Nila (Oreochromis Niloticus) di Danau Pasang Surut (Studi Kasus: Danau Siombak)

Abstract

The increasing potential for microplastic pollution in Lake Siombak needs to be studied scientifically to understand the level of exposure to aquatic organisms, so this research aims to analyze the shape, color, size, type of polymer, and abundance of microplastics in the gills and digestion of tilapia (Oreochromis niloticus) caught in Lake Siombak, Medan City. Analyzing the influence of fish morphometric factors, rainfall, and fishing location (inlet and midlet) on the abundance of microplastics. Fish sampling was carried out using a purposive sampling method, namely the deliberate selection of samples at inlet and midlet locations based on consideration of the potential for higher exposure to microplastics. Fish harvesting is carried out during high rainfall and low rainfall at the inlet and midlet locations of the lake. Next, the gills and digestive tract were digested using 10% KOH, filtered and then subjected to microscopic observation. The research results show that fragments are the highest form of microplastic with the dominant color being black, which indicates that the source of pollution comes from domestic and anthropogenic activities around the lake with the size of the microplastics found between 45 µm - 5000 µm. The type of polymer found is Polyethylene Terephthalate (PET). There was no influence of fish morphometrics, rainfall and fish collection location on the abundance of microplastics. This research emphasizes the importance of environmental management and controlling plastic waste around Lake Siombak to minimize ecological risks to aquatic organisms.