Microplastics in The Bali Strait: Comparison of Two Sampling Methods

Two methods of microplastics sampling in the Bali Strait, manta net (250 µm mesh size) and plankton net (20 µm mesh size), were compared. The difference in the mesh sizes could result in the difference of the microplastics found. Water samples from both sampling tools were analyzed with filtration and all organic materials were removed using Hydrogen Peroxide. Natrium chloride (NaCl) was used to further separate microplastics and organic materials based on its density. The result identified three types of microplastics found in Bali Strait: fibers, films and fragments with total abundances of microplastics were 32.48 x 10² particles.m^-3 and 16.33 x 10² particles.m^-3 using manta net and plankton net, respectively. These results indicated that the numbers of microplastics per cubic metres was higher using manta net sampling tool compared to plankton net. This may likely caused by the smaller size of the mesh used and also the sampling area covered using manta net.