Ciliates play a curial role in energy transfer from pico- and nano-phytoplankton to mesozooplankton in marine ecosystems. In order to visualize their geographical distributions from the Java Sea to the South China Sea...Ciliates play a curial role in energy transfer from pico- and nano-phytoplankton to mesozooplankton in marine ecosystems. In order to visualize their geographical distributions from the Java Sea to the South China Sea （6~S to 20~N）, the authors investigated the ciliate abundance and species composition in sur- face waters during May 18 to 27 of 2010. The ciliate abundance decreased latitudinally from 3 080 ind./L （~6~S） to 40 ind./L （-~3~N）, and then increased to 1 180 ind./L （-~ 16~N） at the end of the survey. A total of 22 ciliates belonging to 15 genera were identified with the tintinnids accounted for 50% （11 species）; and the species number showed a same spatial change as the ciliate abundance. Moreover, the Strombidium oc- cupied over 50% of total ciliate abundance in most stations and Mesodiniurn and Tintinnopsis contributed to about 18.7% and 11.4%, respectively. In particular, our results indicate that the geographical changes in ciliate abundance were positively regulated by larger nano- and micro-phytoplankton biomass, rather than smaller pico-phytoplankton in the investigated waters.展开更多
Vertical distributions of phytoplankton biomass, compositions and size structure were investigated during the spring-intermonsoon （April 22 to 30） of 2010 along transact 10°N of the Bay of Bengal, northern Indi...Vertical distributions of phytoplankton biomass, compositions and size structure were investigated during the spring-intermonsoon （April 22 to 30） of 2010 along transact 10°N of the Bay of Bengal, northern Indian Ocean. Surface phytoplankton biomass （Chl a） was （0.065±0.009） μg/L, being greater than 80% of which was contributed by pico-phytoplankton （〈3 μm）. The Chl a concen- tration vertically increased to the maximal values at deep chlorophyll maximum （DCM） layer that shoaled eastwards from 75 to 40 m. The Chl a biomass at DCM layer generally varied between 0.2 and 0.4 μg/L, reaching the maximum of 0.56 μg/L with micro-phytoplankton cells （~20 #m） accounting for 58% and nano- （3-20μm） or pico-cells for 15% and 27%, respectively. In particular, the cells concentration coupling well with phosphate level was observed at middle layer （75-100 m） of 87° to 89°E, dominated by micro-cells diatoms （e.g., Chaetoceros atlanticus v. neapolitana, Chaetoceros femur and Pseudonitzsehia sp.） and cyanobacteria （i.e., Trichodesmium hildebrandtii）, With the ceils concentration reached as high as 4.0 × 10^4 and 4.3 × 10^4 cells/L. At the rest of the trans- act however, dinoflagellates （e.g., Amphisdinium carterae and Prorocentrum sp.） were the dominant species, with the cells concentration varying from 0.3×10^3 to 6.8×10^3 cells/L. Our results also indicate that the regulation of large cells （micro-, nano-） on phytoplankton biomass merely occurred at DCM layer of the Bay.展开更多
To understand the distribution of aluminum （A1） under the influence of mesocale eddies in the western South China Sea （SCS）, sea level anomaly, geostrophic current, environmental parameters and reactive A1 were in...To understand the distribution of aluminum （A1） under the influence of mesocale eddies in the western South China Sea （SCS）, sea level anomaly, geostrophic current, environmental parameters and reactive A1 were investigated in the western SCS in August 2013. The highest reactive A1 concentration （（180±64） nmol/L） was observed in the surface waters, indicating a substantial atmospheric input. Vertically, the reactive A1 decreased from the surface high concentration to the subsurface minima at the depth of chlorophyll a （Chl a） maxima and then increased again with depth at most of the stations. The average concentration of reactive A1 in the upper 100 m water column was significantly lower in the cyclonic eddy （（137±6） nmol/L） as compared with that in the non- eddy waters （（180±21） nmol/L）. By contrast, the average concentrations of Chl a and silicate in the upper 100 m water column were higher in the cyclonic eddy and lower in the anticyclonic eddy. There was a significant negative correlation between the average concentrations of reactive Al and Chl a in the upper 100 m water column. The vertical distribution of reactive AI and the negative correlation between reactive A1 and Chl a both suggest that the reactive A1 in the upper water column was significantly influenced by biological removal processes. Our results indicate that mesoscale eddies could regulate the distribution of reactive A1 by influencing the primary production and phytoplankton community structure in the western SCS.展开更多
Relatively few studies have investigated the community structure of zooplankton in the atolls of the central South China Sea. Zooplankton were sampled at nine stations within the lagoon and four facing the seaward ree...Relatively few studies have investigated the community structure of zooplankton in the atolls of the central South China Sea. Zooplankton were sampled at nine stations within the lagoon and four facing the seaward reef-slope in the Huangyan Atoll during May 2015. Lagoonal samples contained 48 zooplankton taxa( H' =2.25±0.95; J =0.70±0.23) with planktonic larvae, copepods, and euphausids contributing 95.63% of total abundance. Seaward oceanic samples contained 114 zooplankton(H ' =5.27±0.27; J =0.90±0.03) with copepods, siphonophores, chaetognaths, appendicularians, and planktonic larvae accounting for 93.66% of abundance. Lagoonal zooplankton abundance was lower than that on the seaward reef-slope. Zooplankton community dif fered significantly between the lagoon and reef-slope groups(R =0.708, P =0.001). The former was dominated by Macruran larvae, Brachyuran larvae, S tylocheiron carinatum, and Acartia spp., while the latter was predominately represented by O ikopleura longicauda, Chelophyes contorta and C opilia mirabilis. Chlorophyll a concentration was significantly higher in the lagoon than the reef slope regions( P <0.01), which may be due to the nutrient input from fishing vessels near the lagoon mouth. Zooplankton abundance was negatively correlated with chlorophyll a concentration(P <0.01). A clear dif ference was observed statistically in the species composition and abundance of zooplankton between the lagoon and the seaward slope at Huangyan Atoll, which suggests that it may be resulted from the influence by natural and anthropogenic interactions.展开更多
Horizontal distributions of phytoplankton abundance,species composition as well as environmental factors were investigated in the surface waters of southern South China Sea (SCS) in early summer (May 16 to June 7) of ...Horizontal distributions of phytoplankton abundance,species composition as well as environmental factors were investigated in the surface waters of southern South China Sea (SCS) in early summer (May 16 to June 7) of 2009.In most areas of southern SCS,the concentrations of nitrogen and phosphorus were very low and DIN/DIP ratios usually were lower than the Redfield N/P Ratio of 16∶1.Nitrogen nutrients were significant lower in the upwelling region off Vietnam.A total of 144 taxa of phytoplankton were identified in the study area.The dominant genera were Prorocentrum,Gonyaulax,Gyrodinium,Scrippsiella and Chaetoceros,respectively.Spatial patterns of early-summer phytoplankton abundance and species composition should be mainly controlled by the upwelling off Vietnam and the discharge of Mekong River in the southern SCS.Diatoms dominated in the nutritious Mekong River Estuary or upwelling region off Vietnam; while dinoflagellates dominated in the oligotrophic pelagic region.The canonical correspondence analysis (CCA) indicates that most of diatoms favor higher levels of silicate and phosphorus,as well as lower temperature; while most of dinoflagellates favor the lower silicate and phosphorous and higher temperature.Correlation and CCA results indicate that silicate,nitrate and temperature were the most relevant environmental factors to regulate the horizontal pattern of early-summer phytoplankton in the surface waters of southern SCS.展开更多
基金The National Natural Science Foundation of China under contract No.41130855Key Laboratory for Exploitation&Utilization ofMarine Fisheries Reource in South China Sea,Ministry of Agriculture under contract No.LSF2011-05Financial Fund of the Ministry of Agricultureunder contract No.NFZX2013
文摘Ciliates play a curial role in energy transfer from pico- and nano-phytoplankton to mesozooplankton in marine ecosystems. In order to visualize their geographical distributions from the Java Sea to the South China Sea （6~S to 20~N）, the authors investigated the ciliate abundance and species composition in sur- face waters during May 18 to 27 of 2010. The ciliate abundance decreased latitudinally from 3 080 ind./L （~6~S） to 40 ind./L （-~3~N）, and then increased to 1 180 ind./L （-~ 16~N） at the end of the survey. A total of 22 ciliates belonging to 15 genera were identified with the tintinnids accounted for 50% （11 species）; and the species number showed a same spatial change as the ciliate abundance. Moreover, the Strombidium oc- cupied over 50% of total ciliate abundance in most stations and Mesodiniurn and Tintinnopsis contributed to about 18.7% and 11.4%, respectively. In particular, our results indicate that the geographical changes in ciliate abundance were positively regulated by larger nano- and micro-phytoplankton biomass, rather than smaller pico-phytoplankton in the investigated waters.
基金The Key Innovation Group Project of Chinese Academy of Sciences under contract No.KZCX2-YW-Q07the National Natural Science Foundation of China under contract No.41130855+5 种基金the Natural Science Foundation of Guangdong under contract No.S2011040000151CAS Knowledge Innovation Program under contract No.SQ20115National Project of Sciences and Technology under contract No.2008FY110100CAS Strategic Pilot Science and Technology under contract No.XDA05030403MEL Young Scientist Visiting Fellowship of State Key Laboratory of Marine Environment ScienceXiamen University under contract No.MELRS 1006
文摘Vertical distributions of phytoplankton biomass, compositions and size structure were investigated during the spring-intermonsoon （April 22 to 30） of 2010 along transact 10°N of the Bay of Bengal, northern Indian Ocean. Surface phytoplankton biomass （Chl a） was （0.065±0.009） μg/L, being greater than 80% of which was contributed by pico-phytoplankton （〈3 μm）. The Chl a concen- tration vertically increased to the maximal values at deep chlorophyll maximum （DCM） layer that shoaled eastwards from 75 to 40 m. The Chl a biomass at DCM layer generally varied between 0.2 and 0.4 μg/L, reaching the maximum of 0.56 μg/L with micro-phytoplankton cells （~20 #m） accounting for 58% and nano- （3-20μm） or pico-cells for 15% and 27%, respectively. In particular, the cells concentration coupling well with phosphate level was observed at middle layer （75-100 m） of 87° to 89°E, dominated by micro-cells diatoms （e.g., Chaetoceros atlanticus v. neapolitana, Chaetoceros femur and Pseudonitzsehia sp.） and cyanobacteria （i.e., Trichodesmium hildebrandtii）, With the ceils concentration reached as high as 4.0 × 10^4 and 4.3 × 10^4 cells/L. At the rest of the trans- act however, dinoflagellates （e.g., Amphisdinium carterae and Prorocentrum sp.） were the dominant species, with the cells concentration varying from 0.3×10^3 to 6.8×10^3 cells/L. Our results also indicate that the regulation of large cells （micro-, nano-） on phytoplankton biomass merely occurred at DCM layer of the Bay.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11020305the National Basic Research Program(973 program)of China under contract No.2015CB452903+2 种基金the Special Fund for Agro-scientific Research in the Public Interest under contract No.201403008the National Project of Basic Sciences and Technology under contract No.2017FY201404the National Natural Science Foundation of China under contract Nos 41506150 and 41276162
文摘To understand the distribution of aluminum （A1） under the influence of mesocale eddies in the western South China Sea （SCS）, sea level anomaly, geostrophic current, environmental parameters and reactive A1 were investigated in the western SCS in August 2013. The highest reactive A1 concentration （（180±64） nmol/L） was observed in the surface waters, indicating a substantial atmospheric input. Vertically, the reactive A1 decreased from the surface high concentration to the subsurface minima at the depth of chlorophyll a （Chl a） maxima and then increased again with depth at most of the stations. The average concentration of reactive A1 in the upper 100 m water column was significantly lower in the cyclonic eddy （（137±6） nmol/L） as compared with that in the non- eddy waters （（180±21） nmol/L）. By contrast, the average concentrations of Chl a and silicate in the upper 100 m water column were higher in the cyclonic eddy and lower in the anticyclonic eddy. There was a significant negative correlation between the average concentrations of reactive Al and Chl a in the upper 100 m water column. The vertical distribution of reactive AI and the negative correlation between reactive A1 and Chl a both suggest that the reactive A1 in the upper water column was significantly influenced by biological removal processes. Our results indicate that mesoscale eddies could regulate the distribution of reactive A1 by influencing the primary production and phytoplankton community structure in the western SCS.
基金Supported by the National Science and Technology Major Project(No.2012FY112400)the National Basic Research Program of China(973 Program)(No.2015CB452900)+2 种基金the Science and Technology Basic Resources Investigation Program of China(No.2017FY201404)the National Natural Science Foundation of China(No.41576125)the Science and Technology Planning Project of Guangdong Province,China(No.2017B030314052)
文摘Relatively few studies have investigated the community structure of zooplankton in the atolls of the central South China Sea. Zooplankton were sampled at nine stations within the lagoon and four facing the seaward reef-slope in the Huangyan Atoll during May 2015. Lagoonal samples contained 48 zooplankton taxa( H' =2.25±0.95; J =0.70±0.23) with planktonic larvae, copepods, and euphausids contributing 95.63% of total abundance. Seaward oceanic samples contained 114 zooplankton(H ' =5.27±0.27; J =0.90±0.03) with copepods, siphonophores, chaetognaths, appendicularians, and planktonic larvae accounting for 93.66% of abundance. Lagoonal zooplankton abundance was lower than that on the seaward reef-slope. Zooplankton community dif fered significantly between the lagoon and reef-slope groups(R =0.708, P =0.001). The former was dominated by Macruran larvae, Brachyuran larvae, S tylocheiron carinatum, and Acartia spp., while the latter was predominately represented by O ikopleura longicauda, Chelophyes contorta and C opilia mirabilis. Chlorophyll a concentration was significantly higher in the lagoon than the reef slope regions( P <0.01), which may be due to the nutrient input from fishing vessels near the lagoon mouth. Zooplankton abundance was negatively correlated with chlorophyll a concentration(P <0.01). A clear dif ference was observed statistically in the species composition and abundance of zooplankton between the lagoon and the seaward slope at Huangyan Atoll, which suggests that it may be resulted from the influence by natural and anthropogenic interactions.
基金The National Project of Basic Science and Technology under contract No. 2008FY110100the Key Innovation Group Project of Chinese Academy of Sciences under contract No. KZCX2-YW-Q07+1 种基金the National Natural Science Foundation of China under contract Nos 41006066 and 41130855the Knowledge Innovation Program of Chinese Academy of Sciences under contract No. SQ200907
文摘Horizontal distributions of phytoplankton abundance,species composition as well as environmental factors were investigated in the surface waters of southern South China Sea (SCS) in early summer (May 16 to June 7) of 2009.In most areas of southern SCS,the concentrations of nitrogen and phosphorus were very low and DIN/DIP ratios usually were lower than the Redfield N/P Ratio of 16∶1.Nitrogen nutrients were significant lower in the upwelling region off Vietnam.A total of 144 taxa of phytoplankton were identified in the study area.The dominant genera were Prorocentrum,Gonyaulax,Gyrodinium,Scrippsiella and Chaetoceros,respectively.Spatial patterns of early-summer phytoplankton abundance and species composition should be mainly controlled by the upwelling off Vietnam and the discharge of Mekong River in the southern SCS.Diatoms dominated in the nutritious Mekong River Estuary or upwelling region off Vietnam; while dinoflagellates dominated in the oligotrophic pelagic region.The canonical correspondence analysis (CCA) indicates that most of diatoms favor higher levels of silicate and phosphorus,as well as lower temperature; while most of dinoflagellates favor the lower silicate and phosphorous and higher temperature.Correlation and CCA results indicate that silicate,nitrate and temperature were the most relevant environmental factors to regulate the horizontal pattern of early-summer phytoplankton in the surface waters of southern SCS.
