牡蛎养殖对大鹏澳环境因子与浮游菌落扰动研究

Study on disturbance of oyster culture on environmental factors and bacterioplankton in Dapeng Cove

为评估牡蛎养殖对典型半封闭海湾环境及其生态系统的影响,深入理解其在海洋环境治理和修复中的地位和作用,采用高通量测序技术,对位于典型城市半封闭海湾——大鹏澳的牡蛎养殖区4个季节的水体菌落结构和功能变化进行了分析,并对比了养殖区与对照区在水体和沉积物环境因子的差异特征。结果表明,牡蛎养殖对大鹏澳水体营养盐等环境因子的扰动相对较小,但其生物沉积作用却增强了海区总有机碳(Total organic carbon,TOC)、硫化物(Sulfide,Sul)和部分重金属的富集。高通量测序结果显示,冬季牡蛎养殖区中的绿弯菌门、脱硫杆菌门和放线菌门等菌落的相对丰度显著高于对照区(p<0.05)。冗余分析(Redundancy analysis,RDA)结果揭示了硅酸盐(SiO32-)、海水表面温度(Sea surface temperature,SST)和盐度是影响冬季牡蛎养殖区与对照区水体菌落结构差异的主要环境因子。此外,基于FAPROTAX模型预测的水体菌落生物地球化学功能分析表明,冬季牡蛎养殖区细菌介导的氮(N)和硫(S)元素的生物地球化学作用显著高于对照区(p<0.05)。综上,牡蛎养殖对大鹏澳海水菌落结构组成有一定的扰动,但其影响程度和范围受到了理化因子的季节性变化和水文条件等综合因素的制约。同时,牡蛎养殖也促进了N和S的生物地球化学循环。

In order to assess the environmental and ecological effects of oyster culture in typical semi-enclosed bays,as well as to elucidate the role and significance of oysters in the management and restoration of marine environments.Based on high-throughput sequencing technology,we explored the characteristics of the changes in the structure and function of water body colonies in the oyster culture area within a typical urban semi-enclosed bay(Dapeng Cove)in four seasons,and compared the characteristics of the differences in environmental factors in the water body and sediment between the culture area and the con-trol area in the four seasons.The results indicate that oyster culture caused relatively little disturbance to environmental factors such as nutrients in the water of Dapeng Cove,but its biological sedimentation enhanced the enrichment of total organic carbon(TOC),sulfides(Sul),and some heavy metals in the sea area.The high-throughput sequencing results show that the relative abun-dance of colonies such as Chloroflexi,Desulfobacteraceae and Actinobacteria in the winter oyster culture area was significantly higher than that in the control area(p<0.05).The redundancy analysis(RDA)reveals that the main environmental factors affect-SiO2-3ing bacterioplankton structure between the oyster culture area and the control area in winter were,sea surface tempera-ture(SST)and salinity.The results of biogeochemical function of water colonies predicted based on the FAPROTAX model show that the biogeochemical effects of nitrogen(N)and sulfur(S)mediated by bacteria in the oyster culture area in winter were significantly higher than those in the control area(p<0.05).In conclusion,oyster culture causes certain disturbances to the bacterial structure and composition of seawater in Dapeng Cove,but its degree and scope of influence are constrained by a combination of factors such as seasonal changes in physical and chemical factors and hydrological conditions.Furthermore,oysters culture fa-cilitates the biogeochemical cycling of elements such as nitrogen and sulfur.