Marine aquaculture regulates dissimilatory nitrate reduction processes in a typical semi-enclosed bay of southeastern China
| Autor: | Lijun Hou, Dongsheng Zheng, Maotian Li, Yinghui Jiang, Guoyu Yin, Min Liu, Cheng Chen, Ping Han, Yanling Zheng |
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| Rok vydání: | 2021 |
| Předmět: |
Pollution
China Nutrient cycle Environmental Engineering Denitrification 010504 meteorology & atmospheric sciences Reactive nitrogen Nitrogen media_common.quotation_subject Aquaculture 010501 environmental sciences 01 natural sciences chemistry.chemical_compound Nitrate Ammonium Compounds Environmental Chemistry Nitrogen cycle Ecosystem 0105 earth and related environmental sciences General Environmental Science media_common Nitrates business.industry General Medicine Bays chemistry Nutrient pollution Environmental chemistry Environmental science business Oxidation-Reduction |
| Zdroj: | Journal of Environmental Sciences. 104:376-386 |
| ISSN: | 1001-0742 |
| DOI: | 10.1016/j.jes.2020.12.025 |
| Popis: | Marine aquaculture in semi-enclosed bays can significantly influence nutrient cycling in coastal ecosystems. However, the impact of marine aquaculture on the dynamics of dissimilatory nitrate reduction processes (DNRPs) and the fate of reactive nitrogen remain poorly understood. In this study, the rates of DNRPs and the abundances of related functional genes were investigated in aquaculture and non-aquaculture areas. The results showed that marine aquaculture significantly increased the denitrification (DNF) and dissimilatory nitrate reduction to ammonium (DNRA) rates and decreased the rate of anaerobic ammonium oxidation (ANA), as compared with non-aquaculture sites. DNF was the dominant pathway contributing to the total nitrate reduction, and its contribution to the total nitrate reduction significantly increased from 66.72% at non-aquaculture sites to 78.50% at aquaculture sites. Marine aquaculture can significantly affect the physicochemical characteristics of sediment and the abundances of related functional genes, leading to variations in the nitrate reduction rates. Although nitrate removal rates increased in the marine aquaculture area, ammonification rates and the nitrogen retention index in the aquaculture areas were 2.19 and 1.24 times, respectively, higher than those at non-aquaculture sites. Net reactive nitrogen retention exceeded nitrogen removal in the aquaculture area, and the retained reactive nitrogen could diffuse with the tidal current to the entire bay, thereby aggravating N pollution in the entire study area. These results show that marine aquaculture is the dominant source of nitrogen pollution in semi-enclosed bays. This study can provide insights into nitrogen pollution control in semi-enclosed bays with well-developed marine aquaculture. |
| Databáze: | OpenAIRE |
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