2018年春季和夏季莱州湾营养盐结构及限制特征

Characteristics of nutrient structures and limitations in Laizhou Bay in the spring and summer of 2018

中文关键词: 莱州湾  无机氮  活性磷酸盐  硅酸盐  营养盐结构  限制特征

英文关键词: Laizhou Bay  Inorganic nitrogen  Phosphorus  Silicate  Characteristics of nutrient structures  Limitation

中文摘要:

      根据2018年5、8月莱州湾的生态调查资料，采用营养盐限制法则及潜在性富营养化评价模式等方法，对莱州湾无机氮(DIN)、活性磷酸盐(PO34–-P)和硅酸盐(SiO23–-Si)的平面分布、结构及限制特征进行了分析。结果显示，2018年5、8月莱州湾的DIN浓度范围为1.64~106.36 μmol/L，平均值为24.18 μmol/L，5月明显高于8月；PO34–-P浓度范围为0~2.010 μmol/L，平均值为0.182 μmol/L，8月明显高于5月；SiO23–-Si浓度变化范围为0.97~78.93 μmol/L，平均值为18.30 μmol/L，8月明显高于5月。DIN、PO34–-P、N/P高值区主要位于莱州湾西部的小清河口和黄河口附近海域；SiO23–-Si、Si/N、Si/P高值区主要位于湾底部、龙口–莱州近岸海域。对营养盐结构的分析表明，莱州湾存在明显的磷限制和枯水期的硅限制，陆源输入是莱州湾营养盐的主要来源。营养盐结构限制平面分布表明，春季莱州-招远养殖区和夏季东营-潍坊养殖区易引发赤潮，夏季莱州–招远养殖区初级生产力受到一定限制，对养殖业造成一定的影响。

英文摘要:

      Based on field data of nutrients observed in Laizhou Bay during May and August 2018, using the methods of nutrient restriction and potential eutrophication assessment standards, the distribution characteristics of nitrogen, phosphorus, and silicate in the Laizhou Bay were analyzed and discussed. The results showed that the concentrations of DIN ranged from 1.64 μmol/L to 106.36 μmol/L with an average content of 24.18 μmol/L and were significantly higher in May. The concentrations of PO34–-P ranged from “not detected” to 2.010 μmol/L with an average content of 0.182 μmol/L, and were significantly higher in August. The concentrations of SiO23–-Si ranged from 0.97 μmol/L to 78.93 μmol/L with an average content of 18.30 μmol/L and were also significantly higher in August. The areas with higher values for DIN, PO34–-P, and N/P ratio were mainly located within the sea area near the Xiaoqing River and Yellow River estuaries in the west of Laizhou Bay. The areas with higher values for SiO23–-Si、Si/N ratio, and Si/P ratio were mainly located at the bottom of Laizhou Bay and near the coast of Longkou-Laizhou. The nutrient structure analysis indicated that availability of PO34–-P was limited in May and August while that of SiO23–-Si was limited in May. The spatial distribution of nutrients in the Laizhou Bay was mainly influenced by the terrestrial inputs, especially during periods of high water levels. This observation aligns with the higher nutrient content of the Xiaoqing River and Yellow River estuaries. SiO23–-Si and PO34–-P were the main limiting factors of primary productivity in May, while DIN and PO34–-P were the main limiting factors of primary productivity in August. The horizontal distribution of nutrient structure restriction indicated that it was easy to cause red tide in Laizhou-Zhaoyuan culture area in spring and Dongying-Weifang culture area in summer. The limited primary productivity in the Laizhou-Zhaoyuan area during summer could substantially influence the aquaculture in this area.