Nutrient burial and environmental changes in the Yangtze Delta in response to recent river basin human activities. (June 2019)

• Record Type: Journal Article
• Authors: Liu, Yueying; Deng, Bing; Du, Jinzhou; Zhang, Guosen; Hou, Lijun
• Is Part Of: Environmental pollution. Volume 249(2019)
• Page Start: 225
• Page End: 235
• Publication Date: 2019-06
• Subjects: Environmental changes -- Sediment records -- Nutrient burial -- Human activities -- Yangtze delta; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.03.030
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: High resolution sediment records in the Yangtze Delta front were constructed to reveal recent environmental changes in response to river basin human activities. Increases in nutrient and organic C influxes that began in the 1950s, together with elevated primary productivity and increased chemical fertilizer application, suggested a shift toward anthropogenic-predominated environmental changes during this period. The depletion of total organic C (TOC), total N (TN), and biogenic Si (BSi), along with the decline in sedimentation rate and coarsening of sediment coincided with the development of hydrological engineering in the river basin from the 1980s. Reservoir Si retention substantially altered river mouth primary productivity community composition from diatoms to non-diatoms, thereby changing the BSi/TOC molar ratio in the sediment profile. Estimation of biogenic component burial fluxes was conducted to assess the variation and potential impacts. A recent dramatic decline in biogenic component burial in the delta area suggested a low nutrient removal efficiency in this region, due to the decrease in sediment discharge. Consequently, more nutrients have been further transported to the inner shelf and open waters instead of being buried in the delta sediment, thereby increasing the environmental pressure in the Yangtze Delta and adjoining coastal area. Graphical abstract: Image 1 Highlights: The decline in nutrient burial rate suggested low nutrient removal efficiency. The anthropogenic-predominated environmental changes began in the 1950s. Increasing hydrological engineering induced the depletion of nutrients since 1980s. Abstract : A recent decline in nutrient burial in the Yangtze Delta was found suggesting decreasing nutrient removal efficiency and increasing environmental pressure.