| dc.description.abstract | Fragments of riparian forests in agricultural landscapes, due to their exposure to abiotic and anthropogenic factors, experience a higher rate of deforestation which leads to a net loss of species in the area. To reduce the impact on biodiversity and freshwater ecosystem services, monitoring and knowledge of how deforestation affects the biodiversity in these forest fragments are necessary. This can ensure that policies are being followed and prevent further damage to this important ecosystem. Environmental DNA (eDNA) metabarcoding is a promising tool in biodiversity assessments and monitoring. It is effective, reliable, and less time-consuming compared to conventional methods. This exploratory study aims to assess the aquatic biodiversity of arthropods and fish in a stream of a fragmented riparian forest using eDNA metabarcoding and to investigate the differences in abundance between the forested and deforested areas. To do this, eDNA samples of bulk aquatic arthropods and water samples were obtained using two types of nets for the arthropods and Sterivex filters for the free-floating DNA from fish. Samples were collected in September and October 2019 in Paragominas, Pará state, Brazil. PCR amplification, of the extracted DNA, was done using two metabarcoding primer sets. A COI primer for arthropod detection from the bulk samples and a 12S primer was used for detecting fish taxa from the water eDNA samples. We identified ten distinct orders for arthropods in 102 Amplicon Sequence Variants (ASVs) from the bulk samples and six distinct orders for fish in 62 ASVs were detected in the eDNA water samples. Here we show that DNA metabarcoding can be used to detect the aquatic biodiversity of arthropod orders and fish families. The results show that the canopy cover affected the total abundance for both datasets and that the differences between the forested and deforested areas for arthropods were statistically significant, however, we found no evidence for this in the fish community. The estimated richness and relative abundance suggest that there was a difference in the arthropod community composition between sampling points and the opposite was found for the fish community composition. eDNA metabarcoding can provide invaluable information on how canopy cover affects the aquatic biodiversity found in riparian forest fragments. | eng |