Submarine groundwater discharge(SGD),which can be traced using naturally occurring radium isotopes,has been recognized as a significant nutrient source and land-ocean interaction passage for the coastal waters of the ...Submarine groundwater discharge(SGD),which can be traced using naturally occurring radium isotopes,has been recognized as a significant nutrient source and land-ocean interaction passage for the coastal waters of the Daya Bay,China.However,uncertainties in assessing SGD fluxes must still be discussed in detail.In this study,we attempted to utilize the Monte Carlo method to evaluate the uncertainties of radium-derived SGD flux in the northeast and entirety of the Daya Bay.The results show that the uncertainties of the SGD estimate in the northeast bay are very sensitive to variations in excess radium inventories as well as radium inputs from bottom sediments,while the uncertainties of the SGD estimate for the entire bay are strongly affected by fluctuations in radium inputs from bottom sediments and radium end-members of SGD.This study will help to distinguish the key factors controlling the accuracy of SGD estimates in similar coastal waters.展开更多
By using flow cytometry techniques, we investigated the abundance and composition of the heterotrophic prokaryotes, virioplankton and picophytoplankton community in the Pearl River Estuary and Daya Bay in the summer o...By using flow cytometry techniques, we investigated the abundance and composition of the heterotrophic prokaryotes, virioplankton and picophytoplankton community in the Pearl River Estuary and Daya Bay in the summer of 2012. We identified two subgroups of prokaryotes, high nucleic acid(HNA) and low nucleic acid(LNA), characterized by different nucleic acid contents. HNA abundance was significantly correlated with larger phytoplankton and Synechococcus(Syn) abundance, which suggested the important role of organic substrates released from primary producers on bacterial growth. Although LNA did not show any association with environmental variables, it was a vital component of the microbial community. In contrast to previous studies, the total virioplankton concentration had a poor relationship with nutrient availability. The positive relationship between large-sized phytoplankton abundance and the V–I population confirmed that V–I was a phytoplankton-infecting viral subgroup. Although the V–II group(bacteriophages)was dominant in the virioplankton community, it was not related with prokaryotic abundance, which indicated factors other than hosts controlling V–II abundance or the uncertainty of virus-host coupling. With respect to the picophytoplankton community,our results implied that river input exerted a strong limitation to Syn distribution in the estuary, while picoeukaryotes(Euk) were numerically less abundant and showed a quite different distribution pattern from that of Syn, and hence presented ecological properties distinct from Syn in our two studied areas.展开更多
基金The Project of Key Laboratory of Marine Environmental Survey Technology and Application,Ministry of Natural Resources under contract No.MESTA-2021-D006the China Ocean Development Foundation under contract No.CODF-002-ZX-2021+5 种基金the Science and Technology Plan Projects of Guangdong Province under contract No.2021B1212050025the Director’s Foundation of South China Sea Bureau of Ministry of Natural Resources under contract No.230201the Research Fund Program of Guangdong Provincial Key Laboratory of Applied Marine Biology under contract No.LAMB20221007the Natural Science Foundation of Guangdong Province of China under contract No.2017A030310592the Key Program of Bureau Director of State Oceanic Administration under contract No.180104the Open Project of State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences under contract No.LTO1709.
文摘Submarine groundwater discharge(SGD),which can be traced using naturally occurring radium isotopes,has been recognized as a significant nutrient source and land-ocean interaction passage for the coastal waters of the Daya Bay,China.However,uncertainties in assessing SGD fluxes must still be discussed in detail.In this study,we attempted to utilize the Monte Carlo method to evaluate the uncertainties of radium-derived SGD flux in the northeast and entirety of the Daya Bay.The results show that the uncertainties of the SGD estimate in the northeast bay are very sensitive to variations in excess radium inventories as well as radium inputs from bottom sediments,while the uncertainties of the SGD estimate for the entire bay are strongly affected by fluctuations in radium inputs from bottom sediments and radium end-members of SGD.This study will help to distinguish the key factors controlling the accuracy of SGD estimates in similar coastal waters.
基金supported by the National Basic Research Program (973 Program) of China (Nos. 2015CB452905, 2015CB452903)the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA11020205)+1 种基金Fund of Key Laboratory of Global Change and Marine-Atmospheric Chemistry, SOA, (GCMAC1209)Public science and technology research funds projects of ocean (201105015-06)
文摘By using flow cytometry techniques, we investigated the abundance and composition of the heterotrophic prokaryotes, virioplankton and picophytoplankton community in the Pearl River Estuary and Daya Bay in the summer of 2012. We identified two subgroups of prokaryotes, high nucleic acid(HNA) and low nucleic acid(LNA), characterized by different nucleic acid contents. HNA abundance was significantly correlated with larger phytoplankton and Synechococcus(Syn) abundance, which suggested the important role of organic substrates released from primary producers on bacterial growth. Although LNA did not show any association with environmental variables, it was a vital component of the microbial community. In contrast to previous studies, the total virioplankton concentration had a poor relationship with nutrient availability. The positive relationship between large-sized phytoplankton abundance and the V–I population confirmed that V–I was a phytoplankton-infecting viral subgroup. Although the V–II group(bacteriophages)was dominant in the virioplankton community, it was not related with prokaryotic abundance, which indicated factors other than hosts controlling V–II abundance or the uncertainty of virus-host coupling. With respect to the picophytoplankton community,our results implied that river input exerted a strong limitation to Syn distribution in the estuary, while picoeukaryotes(Euk) were numerically less abundant and showed a quite different distribution pattern from that of Syn, and hence presented ecological properties distinct from Syn in our two studied areas.
