Above and in the undergroundJemec Kokalj, Anita (Avtor) Fišer, Cene (Avtor) Laforsch, Christian (Avtor) Löder, Martin G.J. (Avtor) groundwatercrustaceansmicroplasticsmonitoringAlthough microplastic contamination is intensively studied in aquatic ecosystems, subterranean habitats are rarely considered especially with respect to the exposure of biota. We conducted a pilot sampling campaign to investigate differences in microplastic contamination in surface and cave dwelling organisms from the same functional feeding guild. Samples from a pair of amphipods (surface- Synurella ambulans, cave- Niphargus stygius) and a pair of isopods (surface and cave population Asellus aquaticus) were obtained from the sinking river Pivka in the Slovenian karst region. We used a state-of-the-art analytical pipeline that included plastic-conserving purification, rigorous chemical detection and automated analysis including quality assurance/quality control. Microplastic particles were found in both surface and cave crustaceans. Most of the plastic particles detected were fragments, with a small proportion of fibres and no spheres. The largest proportion of particles found in the organisms fell within the size range of 20–50 μm, followed by the range of 50–100 μm. However, a few fibres were larger (> 500 μm) but were in the size range of food particles previously found in crustaceans. The total number of particles (reaching up to 70 particles/pool of specimens) seem not to be related to the type of habitat where the animals were collected (surface-subterranean), but rather to the taxon and feeding strategy of the animals. These preliminary results on a limited number of samples imply a taxon-specific risk of microplastic ingestion suggesting that different taxa should be monitored to obtain a holistic overview of microplastic contamination of groundwater biota. This short communication emphasizes the need for more extensive sampling campaigns focusing on groundwater biota and covering a larger number of organisms. Future studies should also include monitoring water and sediments to establish a better link between the presence of microplastics in the environment and their accumulation in organisms.20252026-05-18 09:49:38Članek v reviji182580sl