Macroplastic abundance at Lake Singkarak riparian, West Sumatera

Abstract Macroplastic waste has been spotted around the shoreline and the waters of Lake Singarak, West Sumatra. Macroplastic waste has been the main source of microplastic pollution in the marine and freshwater environment. This study aimed to determine the types and abundance of macroplastic waste in the riparian area of Lake Singkarak. Macropalstic waste collection was carried out using a 0.25 m 2 square transect with a radius of 10 m at six sampling locations around the lake. The collected macroplastic waste was then sorted by its type and calculated to determine the abundance of each type. The six collection points, the most abundant macroplastic waste was at a hotel area (Sumpur) with a waste weight of 3.07 kg/m 2 , while the shoreline area (Batu Baraguang) with less human activity was the location with the lowest waste abundance of 0.53 kg/m 2 . The dominating types of macroplastic waste at Sumpur Hotel were plastic film (33%) and hard plastic-fragment (19%). Not only at Sumpur Hotel, the plastic film type also became the most dominant type of macroplastic waste observed in all sampling locations, except at the main river inlet area (Sumani) where the most dominant type found was styrofoam. Overall, there were four types of macroplastic waste that dominated in the riparian of Lake Singkarak, namely plastic film, food bag packaging, hard plastic fragments, also bottle and cup packaging. A high abundance of macropalstic waste in the riparian area could pose a risk of microplastic pollution in Lake Singkarak.