Determination of Microplastic Compounds in Some Species of Freshwater Snails in Brantas River, East Java, Indonesia

This research examines microplastic contamination patterns in three ecologically significant freshwater gastropods—Pomacea canaliculata, Filopaludina javanica, and Sulcospira testudinaria—in Indonesia's Brantas River system. Through systematic sampling at three downstream locations, we quantified and characterized microplastics within the digestive tracts of these molluscan species. The results demonstrate universal microplastic ingestion across all taxa, though with notable interspecific variation. The invasive P. canaliculata showed the highest contamination levels (4.5 microplastic particles per individual, average weight 15.2g), predominantly comprising textile fibers and plastic fragments. In contrast, F. javanica specimens (average 10.8g) contained primarily cosmetic microbeads and packaging films (2.7 particles/individual), while the native S. testudinaria (8.5g average) accumulated industrial pellets and synthetic microfibers (3.2 particles/individual). This particle diversity—spanning six distinct microplastic categories—points to multiple pollution pathways within the watershed, from laundry effluent to agricultural runoff and improper waste disposal. The species-specific accumulation patterns likely reflect differences in feeding ecology and microhabitat preferences, with surface-feeding snails more exposed to buoyant films and water column feeders ingesting suspended fibers. These findings not only establish baseline contamination data for tropical freshwater systems but also underscore the urgent need for targeted mitigation strategies addressing the dominant microplastic sources identified. The demonstrated bioaccumulation in edible species raises particular concerns for local communities relying on river resources, highlighting the interconnected nature of aquatic ecosystem health and human welfare in developing watersheds.