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论文类型：期刊论文

发表时间：2016-01-01

发表刊物：2nd Contaminated Land, Ecological Assessment and Remediation (CLEAR 2014) Conference - Environmental Pollution and Remediation

收录刊物：SCIE、CPCI-S、PubMed、Scopus

卷号：23

期号：2

页面范围：1300-1311

ISSN号：0944-1344

关键字：Mariculture; Nitrogen; Phosphate; Dual isotope of nitrate; Nitrate sources; Laizhou Bay

摘要：Reclamation along coastal zones is a method that has been used to relieve the problems of strained resources and land. Aquaculture, as one of the major man-made activities in reclamation areas, has an environmental impact on coastal waters. The effluents from aquaculture ponds are known to enrich the levels of nutrients such as nitrogen and phosphate. The goals of the present study are to evaluate the environmental impact of mariculture on coastal waters in the east coast of Laizhou Bay, China, and to identify the nitrate sources. Monitoring the concentrations of dissolved nitrogen and phosphate was used to assess their impact on the water quality of coastal waters. A dual isotope (delta N-15-NO3 (-) and delta O-18-NO3 (-)) approach was used to identify the nitrate sources. Higher dissolved nitrogen concentrations (NH4 (+) and NO3 (-)) than PO4 (3-) concentrations associated with enriched delta N-15-NO3 (-) values were observed in the drainage channels, sea cucumber ponds, and groundwater, which indicated that aquaculture activity has more influence on nitrogen nutrients than on phosphate nutrients. In this coastal area with seawater intrusion, nitrogen released from sea cucumber ponds accumulated in nearshore water and migrated in the offshore direction in groundwater currents. This behavior results in nitrogen enrichment in groundwater within the hinterland. Isotopic data indicate that mixing of multiple nitrate sources exists in groundwater, and nitrogen from mariculture is the main source.