Sediment Legacy of Aquaculture Drives Endogenous Nitrogen Pollution and Water Quality Decline in the Taipu River–Lake System

作者：Jingyi Huang, Fengyan Tian, Yuanxing Huang, Hong Tao, Feipeng Li · 发表于：Water · 年份：2025 · DOI：10.3390/w17132000 · 被引用次数：5 · 研究领域：Soil and Water Nutrient Dynamics、Aquatic Ecosystems and Phytoplankton Dynamics、Water Quality and Pollution Assessment

Excessive nitrogen accumulation from aquaculture poses a significant threat to water quality in river–lake systems. This study investigated the Taipu River and five interconnected lakes to analyze the forms, spatial distribution, and ecological impact of nitrogen in both water and surface sediments. Sediment total nitrogen (TN), ammonium nitrogen (NH4+-N), and nitrate nitrogen (NO3−-N) were measured, with aquaculture-dominated lakes such as Xueluoyang Lake and Caodang Marsh exhibiting significantly higher sedimentary TN concentrations than the Taipu River. In Xueluoyang Lake, the average TN content reached 1037.3 mg/kg—1.87 times higher than in the river—highlighting the legacy effect of historical intensive aquaculture. Correlation analyses showed strong associations between sediment NH4+-N and NO3−-N and nitrogen levels in overlying water, confirming sediments as a major endogenous nitrogen source. Multivariate statistical methods, including Pearson’s correlation, hierarchical clustering, and principal component analysis, were applied to elucidate spatial patterns and key influencing factors. Water quality evaluation indices and sediment organic pollution assessments revealed widespread TN exceedance, particularly in dry seasons, with water quality deteriorating to Class V or worse. These results underscore the need for strengthened control of sedimentary nitrogen release and effective management of agricultural non-point source pollution to restore and protect water qualit...