大鹏澳养殖区柱状沉积物中氮、磷的分布特征及污染状况研究

Distribution characteristics and pollution of nitrogen and phosphorus in core sediments of marine culture area in Dapeng Cove

为研究海水养殖对海湾沉积物的累积影响,对大亚湾的大鹏澳养殖区沉积物柱状样中总氮、总磷和有机碳的含量及剖面分布特征进行了研究,并探讨了海水养殖区沉积物中氮、磷的污染状况。结果表明,网箱养殖区、贝类养殖区和对照区等3个区域柱状样中总氮的含量范围分别为638.2—3803.9mg·kg-1、740.9—2152.1mg·kg-1和343.2—471.9mg·kg-1,总磷的含量范围分别为344.7—3233.9mg·kg-1、297.9—497.5mg·kg-1和650.2—1327.2mg·kg-1,有机碳的含量范围分别为0.96%—2.22%、0.87%—1.13%和0.69%—0.95%。该三个因子的含量均从底层至表层呈增加趋势,但网箱养殖区上层增加幅度最为剧烈,贝类区次之,对照区变化幅度最小。所有柱状样中,总氮含量均超标,但网箱养殖区总氮污染最为严重,贝类养殖区次之,对照区最轻;网箱养殖区的总磷在上层的不同深度超标,而贝类养殖区及对照区柱状样的总磷含量均未超标。

In order to study accumulation effects of marine culture on sediments, the contents and profile distribution characteristics of total nitrogen （TN）, total phosphorus （TP） and total organic carbon （TOC） in core sediments from marine culture areas of Dapeng Cove in the Daya Bay were investigated. The pollution status of nitrogen and phosphorus of marine culture area were discussed. The results show that the contents of TN in cage culture, shellfish culture and control areas are in the range of 638.2-3 803.9mg·kg^-1, 740.9-2 152.1mg·kg^-1 and 343.2-471.9mg·kg^-1, respectively; the contents of TP are in the range of 344.7-3 233.9mg·kg^-1, 97.9-497.5mg·kg^-1and 650.2-1 327.2mg·kg^-1, respectively; the contents of TOC are in the range of 0.96%-2.22%, 0.87%-1.13% and 0.69%-0.95%, respectively. The vertical distributions of the TN, TP and TOC contents increased from the bottom to surface layers in the study areas and the variation range in upper layers was greater than that in lower layers. The profile distributions of the contents increased most drastically in the cage culture area, followed by those in the shellfish culture area and least in the control area. The contents of TN in core sediment samples all exceeded the assessment standard, while the most serious one was in the cage culture area, followed by the shellfish area and least in the control area. The contents of TP only exceeded the standard in the cage culture area in the surface layer, while the contents of TP in the shellfish culture area and control area did not exceed the assessment standard.