The presence of microplastics in Surabaya coastal area and its correlation with conventional water quality parameters

Abstract Microplastic’s existence has gained much attention due to its toxicity and harmful effects on marine life. One of the microplastic behaviours in the environment is to absorb hydrophobic pollutants. This behaviour might increase the toxicity of microplastics, affect the concentration of contaminants, and harm the environment. Kenjeran coastal area is a hotspot for human activities in Surabaya City, such as tourist, military training, and fishing activities. Therefore, the Kenjeran coastal area has a high potential to be polluted by plastics and microplastics. This study aimed to identify the abundance and polymer types of microplastics, as well as their correlations with chemical oxygen demand (COD) and total suspended solids (TSS) concentrations in the seawater of the Kenjeran coastal area. Sampling was conducted at three different points in March and April 2024. The average abundance of microplastics obtained was 63-102 particles/L. Meanwhile, the polymer types obtained were polyethylene, polystyrene, ethylene vinyl acetate, and polycarbonate. The correlation test results show that microplastic abundances do not have a significant correlation with COD and TSS concentration in seawater. This study can be used for further research in emerging pollutants and decision-making processes regarding plastic management from the source to the sea.