First evidence of microplastic pollution in mangrove sediments and its ingestion by coral reef fish: Case study in Biawak Island, Indonesia

Abstract Introduction Microplastics (MPs) have emerged as one of the global principal marine environmental problems in many countries, including Indonesia. However, fewer studies have been conducted on the MP impact on aquatic organisms. Thus, the present case study aimed to investigate the presence of MPs in mangrove sediments and coral reef fish in Biawak Island, West Java, Indonesia. Materials and methods The present study used a case study in which samples were collected at specific locations and time. Fish (15 individuals of three family taxa) and sediments were collected from three sampling stations (A, B, and C) at Biawak Island, West Java Province, Indonesia, in February 2023. The types and numbers of MPs were investigated under a monocular microscope. Results MPs were found in all samples of sediments and the digestive tract of coral reef fish. In sediments, MP abundances were recorded at 1,422 particles kg −1 dw sediment at station A, 1,185 particles kg −1 dw sediment at station B, and 59.8 particles kg −1 dw sediment at station C. The MPs in the fish digestive tracts were 726.17 particles kg −1 fish in station A, 827.99 particles kg −1 fish in station B, and 1670.42 particles kg −1 fish in station C. Conclusion MPs have contaminated sediments on Biawak Island, with higher abundances in areas of greater mangrove coverage. Also, coral reef fish from all three families were ingesting MPs, of which Lutjanidae was identified as the largest amount in their digestive tract.