Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing act...Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.展开更多
This study conducted four cruises during 2014–2017 to investigate relationships between macrobenthic communities and sediment contaminations in sea area around the Zhoushan Archipelago.Fourteen sites were categorized...This study conducted four cruises during 2014–2017 to investigate relationships between macrobenthic communities and sediment contaminations in sea area around the Zhoushan Archipelago.Fourteen sites were categorized into three groups:high total heavy metal contamination content(HHMC),high total petroleum hydrocarbon content(HTPH),and low content ratio of heavy metal contamination content to total petroleum hydrocarbon content(HMC/TPH)areas.Four main taxa of macrofauna(polychaetes,bivalves,gastropods,and crustaceans)were determined to respond to environmental factors differently.While tolerant polychaetes being the minimal impact by environmental factors,bivalves were threated by heavy metal pollutions in sediment.Additionally,body size distribution frequency demonstrated that macrofauna in the low HMC/TPH areas were less disturbed by contamination than those in the HHMC and HTPH areas.The result represented the presentation of sensitive species while tolerant species are usually considered as small size organisms.Overall,this study confirmed the hypothesis that the contamination levels of small-scale patches is indicated by the condition of macrobenthic communities.展开更多
Obvious spatiotemporal heterogeneity is a distinct characteristic of ecosystems in subtropical bays.To aid targeted management and ecological restoration in long and narrow semi-enclosed subtropical bays,we analyzed s...Obvious spatiotemporal heterogeneity is a distinct characteristic of ecosystems in subtropical bays.To aid targeted management and ecological restoration in long and narrow semi-enclosed subtropical bays,we analyzed seasonal and regional differences in long-term changes(1980-2019)in the biomass and abundance of large mesozooplankton(LMZ;>505μm)in Xiangshan Bay,Zhejiang,China.We found spatiotemporal heterogeneity in the historical changes of LMZ.Significant negative trends in LMZ biomass were found in the inner and middle bay during the warm season(summer and autumn),when the nutrient concentration(especially dissolved inorganic nitrogen)and temperature increased simultaneously.Nutrient changes in Xiangshan Bay began in the late 1980s or early 1990s,coinciding with large-scale fish cage development.A rapid decline in LMZ biomass occurred after 2005 when power plants commenced operation,accelerating the warming trend.Therefore,the joint stress of eutrophication and warming likely precipitated the decline in LMZ biomass.Conversely,a significant increase in LMZ biomass was found in the outer bay in spring.This trend was consistent with the trend of LMZ biomass near the Changjiang(Yangtze)River estuary,which indicates that the pelagic ecosystem in the outer bay was aff ected by water from the Changjiang River estuary during spring.Based on our results,ecosystem management and restoration in semi-enclosed subtropical bays should focus on internal waters,which have a poor capacity for water exchange.For Xiangshan Bay,the changes in the Changjiang River estuary ecosystem during the cold season(winter and spring)should also be considered.展开更多
Macrobenthic organisms are commonly employed as biomonitors for environmental risk assessment.In this study,we aimed to investigate the spatial and temporal patterns of the macrobenthic community,which is influenced b...Macrobenthic organisms are commonly employed as biomonitors for environmental risk assessment.In this study,we aimed to investigate the spatial and temporal patterns of the macrobenthic community,which is influenced by environmental factors of sediments and bottom water layer.We sampled a total of 12,11,10,and 11 stations in the Shengsi Archipelago during June 2010,August 2010,November 2020,and April 2021 respectively.A total of 124 species of macrobenthos were identified,with polychaetes being the dominant group.The abundance,biomass,and diversity indices exhibited no significant temporal differences.Similarly,biodiversity did not exhibit a clear spatial gradient,likely due to the small study area and the absence of significant differences in key factors such as depth.However,the stations with the lowest biodiversity values consistently appeared in the southwest region,possibly due to the impact of human activities.Significant differences in the macrobenthic community were observed between all months except between June and August,and mollusk Endopleura lubrica and polychaete Sigambra hanaokai were important contributors to these differences according to the results of the Similarity Percentages analysis.Suspended particulate matter(SPM)was identified as the primary driving factors of macrobenthic variability.In summary,the community structure underwent temporal changes influenced by complex current patterns,while biodiversity remained relatively stable.This study contributes to our understanding of the key environmental factors affecting macrobenthic communities and biodiversity.It also provides valuable data support for the long-term monitoring of macrobenthos and the environment in the Shengsi Archipelago.展开更多
基金Supported by the Scientifi c Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources(MNR)(Nos.JB1906,JG1616,JG1910)the Zhejiang Qingshan Lake Innovation Platform for Marine Science and Technology(No.2017E80001)+4 种基金the Key Projects of Philosophy and Social Sciences Research,Ministry of Education(No.18JZD059)the National Key Technology Research and Development Program of the Ministry of Science and Technology of the China(No.2015BAD08B01)the State Key Laboratory of Satellite Ocean Environment Dynamics(No.SOEDZZ1902)the National Natural Science Foundation of China(No.41806136)the Project of Long Term Observation and Research Plan in the Changjiang Estuary and the Adjacent East China Sea(LORCE,14282)。
文摘Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.
基金he National Key Research and Development Program of China under contract No.2018YFD0900901the Scientific Research Fund of the Second Institute of Oceanography+2 种基金MNR under contract No.JG1916the Natural Science Foundation of Zhejiang Province under contract No.LQ19D060004the National Natural Science Foundation of China under contract No.41806181。
文摘This study conducted four cruises during 2014–2017 to investigate relationships between macrobenthic communities and sediment contaminations in sea area around the Zhoushan Archipelago.Fourteen sites were categorized into three groups:high total heavy metal contamination content(HHMC),high total petroleum hydrocarbon content(HTPH),and low content ratio of heavy metal contamination content to total petroleum hydrocarbon content(HMC/TPH)areas.Four main taxa of macrofauna(polychaetes,bivalves,gastropods,and crustaceans)were determined to respond to environmental factors differently.While tolerant polychaetes being the minimal impact by environmental factors,bivalves were threated by heavy metal pollutions in sediment.Additionally,body size distribution frequency demonstrated that macrofauna in the low HMC/TPH areas were less disturbed by contamination than those in the HHMC and HTPH areas.The result represented the presentation of sensitive species while tolerant species are usually considered as small size organisms.Overall,this study confirmed the hypothesis that the contamination levels of small-scale patches is indicated by the condition of macrobenthic communities.
基金Supported by the National Key Research and Development Program of China(Nos.2018YFD0900901,2018YFD0900905)the Long Term Observation and Research Plan in the Changjiang River estuary and the Adjacent East China Sea Project(LORCE)(No.14282)+1 种基金the National Natural Science Foundation of China(Nos.41806149,41806181,41706125)the NSFC-Zhejiang Joint Fund,China(No.U1709202)。
文摘Obvious spatiotemporal heterogeneity is a distinct characteristic of ecosystems in subtropical bays.To aid targeted management and ecological restoration in long and narrow semi-enclosed subtropical bays,we analyzed seasonal and regional differences in long-term changes(1980-2019)in the biomass and abundance of large mesozooplankton(LMZ;>505μm)in Xiangshan Bay,Zhejiang,China.We found spatiotemporal heterogeneity in the historical changes of LMZ.Significant negative trends in LMZ biomass were found in the inner and middle bay during the warm season(summer and autumn),when the nutrient concentration(especially dissolved inorganic nitrogen)and temperature increased simultaneously.Nutrient changes in Xiangshan Bay began in the late 1980s or early 1990s,coinciding with large-scale fish cage development.A rapid decline in LMZ biomass occurred after 2005 when power plants commenced operation,accelerating the warming trend.Therefore,the joint stress of eutrophication and warming likely precipitated the decline in LMZ biomass.Conversely,a significant increase in LMZ biomass was found in the outer bay in spring.This trend was consistent with the trend of LMZ biomass near the Changjiang(Yangtze)River estuary,which indicates that the pelagic ecosystem in the outer bay was aff ected by water from the Changjiang River estuary during spring.Based on our results,ecosystem management and restoration in semi-enclosed subtropical bays should focus on internal waters,which have a poor capacity for water exchange.For Xiangshan Bay,the changes in the Changjiang River estuary ecosystem during the cold season(winter and spring)should also be considered.
基金The Scientific Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources,China under contract Nos SZ2302 and JG2209.
文摘Macrobenthic organisms are commonly employed as biomonitors for environmental risk assessment.In this study,we aimed to investigate the spatial and temporal patterns of the macrobenthic community,which is influenced by environmental factors of sediments and bottom water layer.We sampled a total of 12,11,10,and 11 stations in the Shengsi Archipelago during June 2010,August 2010,November 2020,and April 2021 respectively.A total of 124 species of macrobenthos were identified,with polychaetes being the dominant group.The abundance,biomass,and diversity indices exhibited no significant temporal differences.Similarly,biodiversity did not exhibit a clear spatial gradient,likely due to the small study area and the absence of significant differences in key factors such as depth.However,the stations with the lowest biodiversity values consistently appeared in the southwest region,possibly due to the impact of human activities.Significant differences in the macrobenthic community were observed between all months except between June and August,and mollusk Endopleura lubrica and polychaete Sigambra hanaokai were important contributors to these differences according to the results of the Similarity Percentages analysis.Suspended particulate matter(SPM)was identified as the primary driving factors of macrobenthic variability.In summary,the community structure underwent temporal changes influenced by complex current patterns,while biodiversity remained relatively stable.This study contributes to our understanding of the key environmental factors affecting macrobenthic communities and biodiversity.It also provides valuable data support for the long-term monitoring of macrobenthos and the environment in the Shengsi Archipelago.
