基于LOICZ收支模型的涠洲岛近海营养盐浓度及结构变化的关键影响因素研究  

Key factors affecting the concentrations and structures of nutrients around Weizhou island based on the LOICZ model

作　　者：方草 宁志铭 韦芬 夏荣林 杨斌 FANG Cao;NING Zhi-ming;WEI Fen;XIA Rong-lin;YANG Bin(School of Marine Sciences/Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea,Guangxi University,Nanning 530004,China;Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf,Beibu Gulf University,Qinzhou 535011,China)

机构地区：[1]广西大学海洋学院广西南海珊瑚礁研究重点实验室,广西南宁530004 [2]北部湾大学广西北部湾海洋灾害研究重点实验室,广西钦州535011

出　　处：《海洋环境科学》2022年第5期689-696,共8页Marine Environmental Science

基　　金：广西自然科学基金项目(2019GXNSFAA185001);广西研究生教育创新计划资助项目(YCSW2021019)。

摘　　要：本文根据2018-2019年广西涠洲岛近海营养盐的时空变化数据,采用海岸带海陆相互作用(LOICZ)营养盐收支模型对涠洲岛南湾营养盐进行收支估算,研究了影响营养盐浓度及结构变化的关键因素。此外,本研究利用流动式反应器(FTR)模拟实验,探究了在不同的有机碳含量条件下,沉积物-水界面营养盐交换对海水营养盐浓度及结构的影响。研究结果表明:(1)受南湾湾外营养盐输入的影响,溶解无机氮(DIN)和溶解无机磷(DIP)的浓度均呈现湾外高、湾内低的趋势;(2)南湾DIN和DIP净收支分别为-9.45×10^(5)mol/a和0.95×10^(5)mol/a,地下水输入和沉积物-水界面营养盐交换分别是湾内DIN和DIP的主要来源,沉积物-水界面营养盐交换是湾内DIN的主要输出途径,而贝类收获移除了湾内96.6%的DIP;(3)在有机碳含量(0.05%~0.23%)梯度变化的FTR实验中,海水流经沉积物后,DIN浓度降低,DIP浓度升高,沉积物-水界面营养盐的交换可以有效降低海水的氮磷比(N/P)。该研究结果可为科学评估营养盐对涠洲岛周围海域珊瑚礁的潜在影响以及近海环境生态管理提供科学依据。We investigated the spatiotemporal variation of nutrients in the coastal seawater around Weizhou island,Guangxi from 2018 to 2019,and clarified the key factors affecting the nutrient concentration and structure using nutrient budget model from the Land-Ocean Interactions in the Coastal Zone(LOICZ)research program.Furthermore,a flow-through reactor(FTR)experiment was implemented to assess the effects of benthic nutrient fluxes on nutrient concentrations and structures under different organic carbon conditions.The results were as followed:(1)The concentrations of dissolved inorganic nitrogen(DIN)and dissolved inorganic phosphorus(DIP)were affected by nutrient inputs outside the south bay,and their concentrations were higher outside the bay than those inside the bay;(2)The net budget values of DIN and DIP were−9.45×10^(5) mol/a and 0.95×10^(5) mol/a.The DIN input to the bay was mainly attributed to the discharge of groundwater,while the DIN output was mainly due to the uptake of DIN by sediments;the release of phosphorus from the sediments contributed the most of DIP input,and the harvest of shellfish removed 96.6%of DIP;(3)In the FTR experiment,DIN concentration decreased and DIP concentration increased after the seawater flowing through the sediments,and thus the nitrogen phosphorus ratio(N/P)in seawater was reduced.The research can provide a basis for scientific assessment of the potential impact of nutrients on the coral reefs around Weizhou island and reasonable suggestions for the management of coastal environment.

关 键 词：涠洲岛 营养盐 沉积物-水界面 养殖活动 N/P 

分 类 号：P734.25[天文地球—海洋化学]