In urban rivers, sediment bacterial populations play an important role in the biogeochemical cycle of nutrient elements. The distribution of nitrogen cycle genes on bacterial populations in urban river sediments, on the other hand, is mostly unclear. In this study, 16S rRNA amplicon sequencing was performed to examine the composition, co-occurrence patterns, and nitrogen cycle mechanism of bacterial communities in urban river sediments exposed to various exogenous pollutants.

Dams are crucial for flood control, water storage, irrigation, power generation, and navigation, and are considered the most significant anthropogenic disturbance in aquatic ecosystems. However, the impact of dams on nitrogen transformation on a wide watershed scale has received little attention. We employed 16S rRNA gene sequencing to explore the microbial dynamics and ecological processes under diverse dam circumstances throughout the Yangtze River to specifically address the influence of dams on nitrogen transformation, as microbial communities play a vital role in aquatic nitrogen transformation.

The Fukushima Daiichi nuclear power plant disaster resulted in radioactive pollution on Japan's northern Honshu Island. The impact of snowmelt and rainfall on soil erosion processes and siltation of small lakes in Miyagi Prefecture (150 km northwest of the power plant) was investigated in this study.