广西钦州湾营养状况季节分析与评价研究

根据2009年1月、4月、8月和11月对钦州湾海域调查结果,分析并评价了该海域营养状况的季节变化。结果表明,钦州湾海域总溶解无机氮(DIN)含量范围在0.023 mg/L~1.750 mg/L,硅酸盐(SiO3-Si)含量范围在0.027 mg/L~3.900 mg/L,磷酸盐(PO4-P)含量范围在0.001 mg/L~0.158 mg/L。NO3-N是DIN的主要存在形式,占62%~78%。不同的营养盐季节分布有所差异。DIN季节分布表现为夏季春季秋季冬季;PO4-P季节分布为春季秋季冬季夏季;SiO3-Si季节变化为夏季秋季春季冬季。从营养结构看,与Justic'等提出的营养盐化学计量限制标准比较符合P限制条件,PO4-P可能成为浮游植物生长的潜在限制因子。按照营养状态指数值,钦州湾海域春季、夏季和秋季表层海水处于富营养化状态,钦州湾内湾富营养化程度高,一旦水文气象条件适宜,从春季到秋季该区域随时都会发生赤潮灾害的可能。

Seasonal Variation and Evaluation on Nutrients in Qinzhou Bay of Guangxi Province

According to the investigation results of Jan. Apr. Aug. and Nov. 2009, the status of nutrients in Qinzhou Bay of Guangxi Province was analyzed. The results showed that the content of total dissolved inorganic nitrogen（DIN） was 0. 023 - 1. 750 mg/L, the content of silicate was 0. 027 - 3. 900 mg/L and the content of phosphate was 0. 001 - 0. 158 mg/L. Nitrate was the most common form of DIN, the proportion of nitrate was 62% - 78% of DIN in Qinzhou Bay. The distribution of nutrients was different in same season. The seasonal distribution for DIN showed summer 〉 spring 〉 autumn 〉 winter. The seasonal distribution of phosphate was spring 〉 autumn 〉 winter 〉 summer and silicate summer 〉 autumn 〉 spring 〉 winter. From the nutrition structure, the phosphate might become a potential factor to limit phytoplankton growth, and compared with limit standard of chemical measure for the nutri- ents, it is accorded with the limit condition of phosphate. According to the value of eutrophic state index, the seawaters of surface were eutrophication state in Qinzhou Bay in spring, summer and autumn, the eutrophication degree of the inner Qinzhou Bay was high, so the red tide disaster might Occur from spring to autumn in case of suitable hydro - meteorological conditions.