Microplastic contamination in aquatic insects from Algerian freshwater ecosystems: a first multi-bioclimatic...

Microplastic pollution is an issue arising in freshwater ecosystems worldwide, yet data from North Africa remains scarce. In this study, aquatic insects were collected from 17 freshwater sites distributed across three bioclimatic regions in Algeria between 2024 and 2025. A total of 25 species belonging to 12 families and 5 orders were analyzed to assess the occurrence and polymer composition of microplastics (MPs). MPs were detected in 72% of the analyzed specimens, with a total of 105 particles identified. Particle sizes ranged from 5.8 to 124 µm, with fibers representing the dominant morphological shape. FTIR analysis recognized polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polystyrene (PS) as the predominant polymers, suggesting multiple anthropogenic contamination sources. Generalized linear model (GLM) analyses revealed significant associations between MP occurrence and functional feeding groups, particularly collector-filterers (p < 0.001) and members of the family Hydropsychidae (p < 0.01). These findings provide the first baseline data on microplastic contamination in freshwater macroinvertebrates from Algeria and highlight the potential usefulness of aquatic insects for monitoring freshwater MP contamination.