Seagrass sponge (Agelas conifera: Demospongia) potential of microplastic accumulation from Pramuka Island, Seribu Islands

Abstract Sponges is a benthic filter feeder, that potentially absorb and accumulate substances from the aquatic environment. Pramuka Island is a small island with tourism area, that could contribute contamination of domestic and anthropogenic waste in its waters, including microplastics. This study aimed to examine the potential for microplastic accumulation in the body tissues of the seagrass-sponge Agelas conifera in Pramuka Island, DKI Jakarta. Sponge samples were collected from two stations around the final disposal site and household liquid waste disposal. Microplastic observations were carried out by adding KOH solution to remove sponge organic matter and saturated NaCl to separate the density. Microplastic observations were carried out using a stereo microscope. The result showed that sponge tissue could accumulate 166.66-300 particles/g of microplastic at both sampling stations, with the highest abundance of fibre types at station 1. The abundance of microplastic in sediment samples is 0.76-0.97 particles/g, with fragment type was found dominantly, whilst microplastic found in the water samples is 1,550 -1,956.66 particles/m 3 , mostly by fibre type (1230 particles/m3 ). The abundance and types of microplastic found in sediment, water and sponges samples showed a significant difference between samples with a significant value of 0.01 (ANOVA, p values).