多核素联合示踪珊瑚礁区颗粒物动力学过程  

Multi-radionuclides for quantifying marine particle dynamic processes in coral reef ecosystem

作　　者：罗柱 林武辉 王一潼 黄思宇 余克服 LUO Zhu;LIN Wu-hui;WANG Yi-tong;HUANG Si-yu;YU Ke-fu(Guangxi Laboratory on the Study of Coral Reefs in the South China Sea,School of Marine Sciences,Guangxi University,Nanning 530004,China;College of Harbor and Coastal Engineering,Jimei University,Xiamen 361021,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]集美大学,港口与海岸工程学院,福建厦门361021

出　　处：《中国环境科学》2025年第3期1576-1586,共11页China Environmental Science

基　　金：国家自然科学基金资助项目(42276044);广西自然科学基金资助项目(2024GXNSFAA010449);广西南海珊瑚礁研究重点实验室开放基金联合资助项目(GXLSCRSCS2023003)。

摘　　要：利用高纯锗γ谱仪对北部湾涠洲岛珊瑚礁区的沉降物、表层沉积物、柱状沉积物中多种放射性核素开展联合分析.在利用^(40)K、颗粒活性核素^(234)Th_(ex)和^(7)Be以及^(238)U-^(232)Th(^(228)Ra)-^(40)K/10三角图解等多核素示踪手段共同证实涠洲岛西侧沉降物来源于表层沉积物再悬浮的基础上,联合使用过剩^(210)Pb的恒定通量恒定沉积速率模式定量计算了涠洲岛西侧海域两柱样(WZ16和WZ20)沉积速率分别为1.46×10^(-3)和2.25×10^(-3)cm/d,该结果仅为相邻站位沉降速率(295×10^(-3)和252×10^(-3)cm/d)的0.50%和0.89%,表明99%以上的沉降物会经历多次强烈的再悬浮过程,最终才能埋藏进入沉积柱样.此外,本研究发现具有较高沉降通量的涠洲岛西侧珊瑚礁区仍有较高的珊瑚幼体补充量,推测是由于强烈的生源沉积物再悬浮为珊瑚虫提供了丰富的异养能量来源.The naturally occurring radionuclides in the sinking particle,surface sediments,and sediment cores near the Weizhou Island in the Beibu Gulf were simultaneously analyzed by high purity germaniumγspectrometer in this study.The sinking particle at the west station of the Weizhou Island was mainly attributed to the strong sediment resuspension that was demonstrated by the combined evidences of^(40)K,^(234)Th_(ex),^(7)Be,and^(238)U-^(232)Th(^(228)Ra)-^(40)K/10 ternary diagram.Sediment accumulation rates(SAR)of two sediment cores(WZ16and WZ20)at the west stations of the Weizhou Island were calculated to be 1.46×10^(-3)and 2.25×10^(-3)cm/d using the constant flux and constant sedimentation rate model of excess^(210)Pb.These^(210)Pb derived-sediment accumulation rates were only 0.50%and 0.89%of the sediment sinking rates(295×10^(-3)and 252×10^(-3)cm/d)derived from sediment trap,quantitatively indicating strong sediment resuspension before the ultimate burial in sediment.Additionally,a high recruitment of coral larvae was observed at the west station with strong sediment resuspension.It was speculated that the strong biogenic sediment resuspension would provide sufficient heterotrophic energy for coral polyps.

关 键 词：珊瑚礁 放射性核素 物源识别 沉积速率 再悬浮 

分 类 号：X55[环境科学与工程—环境工程]