摘要
海底地下水排放(SGD)是陆源物质入海的重要通道,对沿岸物质通量、生物地球化学循环及生态环境都起着重要作用。近些年来,随着近海海水养殖的发展,有关SGD对养殖生态系统的调控作用也备受关注。本研究运用短半衰期核素223Ra和224Ra估算了福建沿岸养殖型海湾——罗源湾的海底地下水排放通量。结果表明,地下水中223Ra[(58.1±40.2)dpm/(100 L)(n=9)]和224Ra[(1637±1118)dpm/(100 L)(n=9)]的活度远高于近岸水体223Ra[(4.49±1.35)dpm/(100 L)(n=15)]和224Ra[(65.5±15.8)dpm/(100 L)(n=15)]的活度。本研究在假设稳态的条件下,运用Ra质量平衡模型,估算出罗源湾SGD通量为(1.91±2.16)×10^(7)m3/d,SGD速率为0.068~0.101 m3/(m^(2)·d),结合地下水端元营养盐浓度计算得出SGD携带的溶解无机氮(DIN)、溶解无机磷(DIP)、溶解硅(DSi)的排放通量分别为(3.23±3.65)×10^(6)mol/d、(6.68±7.55)×10^(4)mol/d、(3.58±4.04)×10^(6)mol/d,分别占总输入量的79.6%、84.8%、75.4%,可见罗源湾沿岸地下水排放携带的营养物质在养殖体系中对于营养盐的收支有显著贡献。
Submarine groundwater discharge(SGD)has been widely recognized as an important pathway for nutrients transport from coastal aquifers to the sea,which plays an important role in coastal material flux,biogeochemical cycle and ecological environment.In recent years,with the development of mariculture,the impact of SGD on the aquaculture ecosystem has attracted much attention.In this paper,223Ra and 224Ra are adopted as tracers to quantify SGD in Luoyuan bay,a coastal aquaculture bay in Fujian.The results shows that the radium activities of 223Ra[(58.1±40.2)dpm/(100 L)(n=9)]and 224Ra[(1637±1118)dpm/(100 L)(n=9)]in groundwater is higher than those of 223Ra[(4.49±1.35)dpm/(100 L)(n=15)]and 224Ra[(65.5±15.8)dpm/(100 L)(n=15)]in the surface water.Assuming steady state and using a radium mass balance model,the SGD rate in Luoyuan bay was estimated to be as(1.91±2.16)×10^(7)m3/d and the discharge rate is 0.068~0.101 m3/m^(2)/d.The fluxes of dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorus(DIP)and dissolved silicon(DSi)carried by SGD were calculated to be(3.23±3.65)×10^(6),(6.68±7.55)×10^(4),(3.58±4.04)×10^(6)mol/d,accounting for 79.6%,84.8%and 75.4%of the total input.Therefore,the nutrient fluxes by SGD contribute significantly to the nutrient budget and nutrient structure as well as coastal aquaculture system.
作者
林心怡
刘建安
于雪晴
彭彤
于涛
杜金洲
LIN Xinyi;LIU Jianan;YU Xueqing;PENG Tong;YU Tao;DU Jinzhou(State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai 200241,China;Laboratory of Marine Isotopic Technology and Environmental Risk Assessment,Third Institute of Oceanography,Ministry of Natural Resources,Xiamen 361005,China)
出处
《海洋环境科学》
CAS
CSCD
北大核心
2023年第5期662-672,683,共12页
Marine Environmental Science
基金
国家自然科学基金项目(41976040)
自然资源部海洋大气化学与全球变化重点实验室开放基金课题(GCMAC2205)。
关键词
海底地下水排放
罗源湾
镭同位素
营养盐收支
海水养殖
submarine groundwater discharge(SGD)
Luoyuan bay
radium isotopes
nutrient budgets
marine agriculture
作者简介
林心怡(1997-),女,浙江温州人,硕士研究生,主要研究方向为同位素海洋学,E-mail:51203904021@stu.ecnu.edu.cn;通信作者:刘建安(1990-),男,副研究员,主要研究方向为同位素海洋学,E-mail:jaliu@sklec.ecnu.edu.cn。
