Microplastics in Gastrointestinal Track of Some Commercial Fishes from Bengkalis Waters, Riau Province Indonesia

Abstract Microplastic is a particle that has a size of <5 mm, where its existence might be able to contaminate the biota in the aquatic environment. This research was conducted in the coastal waters of Bengkalis Island in early 2020 with the aim to determine the types and analyze its abundance of microplastics in each area with suspected different sources of input. Thirty six individual samples of Duri fish (Arius maculatus) , Lomek (Harpodon nehereus) , and Biang (Setipinna breviceps) were collected from the north and south parts of Bengkalis island with the help of local fishermen in each sampling location. The average abundance of microplastics found in the gastrointestinal tract of fish was 62.96 particles/ind which consisted of fiber, film and fragment. The highest microplastics abundance was found in Duri fish (72.22 particles/ind), whilst the lowest was found in Lomek fish (55.56 particles/ind). Although the abundance of microplastic in coastal waters of north Bengkalis (Malacca Straits area) were higher that that in the south of Bengkalis (Begkalis Straits area), statistically they were not significantly different (p>0.05). This was presumably due to differences in oceanographic influences such as current and waves between the two water masses as well as anthropogenic activities in both areas that can affect the spread and distribution of microplastics.