Bioaccumulation of microplastic in intertidal gastropods from Southern Java, Indonesia: Abundance in relation feeding guild

Microplastic pollution has become pervasive in marine ecosystems, with the potential to bioaccumulate in marine organisms, including intertidal gastropods. Feeding behaviour may significantly influence microplastic accumulation, as different feeding strategies determine exposure pathways to microplastic particles. This study characterized microplastics and determined their abundance in intertidal gastropods while analysing the relationship between feeding guilds and microplastic accumulation. Three gastropod species representing different feeding guilds were studied: herbivores (Nerita maxima), carnivores (Tylothais aculeata), and detritivores (Rhinoclavis sinensis). Samples were collected from Balekambang Beach, southern Java, during low tide periods. Microplastics were extracted through tissue digestion and filtration, then characterized morphologically and polymer composition was analyzed using ATR-FTIR. Results revealed microplastics in all specimens, dominated by fragments (94.51%), followed by fibres (4.68%), with predominant particle size of 20- 40 μm (41.53%) and black coloration (64.80%). Polymer analysis identified polystyrene and nylon. Microplastic abundance exhibited a clear gradient across feeding guilds: highest in detritivores (148.21 particles/g), intermediate in carnivores (143.82 particles/g), and lowest in herbivores (56.19 particles/g). These findings demonstrate that feeding ecology significantly influences microplastic bioaccumulation patterns in intertidal gastropods, with sediment-feeding detritivores exhibiting highest vulnerability to microplastic contamination.