Limnetica 42

This study examined the composition and diversity of the invertebrate communities that inhabit the hyporheic zone (HZ) in the upper and lower basins of the Dagua River, a tropical mountain stream, and their relationship with the macrobenthic fauna. In the HZ, different taxa were collected, many of which have been reported in several regions worldwide, suggesting that the biodiversity of the hyporheic community in Colombian rivers may be high. Although the hyporheic and macrobenthic fauna shared a moderate percentage (> 50 %) of taxa, their ecological structures were different. The analysis of hyporheic filtrate water showed the presence of microplastic (MP) fibers as well as fauna, a condition that, based on the literature review, could represent a risk for the normal functioning of this river ecosystem.