春季桑沟湾海域贝类养殖对海水中营养盐的影响研究

Effect of Shellfish Farming on Nutrient Salts of Seawater in Sanggou Bay in Spring

根据2011年春季对桑沟湾海域8个监测点的营养盐的变化特征和历史资料的研究,分析了桑沟湾水域溶解性无机氮(DIN)、总氮(TN)、活性磷酸盐(PO34-)和总磷(TP)浓度变化及它们之间的相互关系,估算了贝类养殖的排泄物对海水污染的贡献率。结果表明,溶解性无机氮的平均浓度为0.106 1 mg/L,NO3-N为主要存在形式,占溶解性无机氮平均含量的78.3%,NH3-N、NO2-N分别占溶解性无机氮平均含量的14.2%和7.5%。总氮的平均浓度为0.234 7 mg/L,溶解性无机氮浓度占总氮浓度的45.2%。活性磷酸盐的平均浓度为0.013 3 mg/L,总磷的平均浓度为0.024 78 mg/L。春季桑沟湾贝类养殖对该海域海水磷含量的贡献率比氮的贡献率大,N/P为17.63,营养水平基本属于贫营养。

Based on nutrient data from eight monitoring stations in Sanggou Bay during spring, the distribution characteristics and changes of nutrients in seawater were analyzed and compared with historical materials. The concentration variation of dissolved inorganic nitrogen（DIN）, total nitrogen（TN）, active phosphate（ PO]- ）and total phosphorus as well as their relationships were observed. In addition, the pollution contribution rate of shellfish farming wastewater was estimated. The results showed that mean concentration of dissolved inorganic nitrogen（DIN） was 0. 106 1 mg/L. NO3 -N was the main component of DIN, accounted for 78.3% of mean DIN content, NH3 - N and NO2 - N accounted for only 14. 2% and 7.5% of mean DIN content, respectively. The mean concentration of TN was 0. 234 7 mg/L. The mean of dissolved inorganic nitrogen accounted for 45. 2% of total nitro- gen. The mean concentration of active phosphate and total phosphorus were 0. 013 3 mg/L and 0. 024 78 mg/L, respectively. The contribution rate to shellfish aquaculture of phosphorus was greater than that of nitrogen in spring in the Sanggou Bay. N/P was 17.63, indicating that the seawater of Sanggou Bay in spring was in an oligotrophic state.