From the synopical CTD sections in the WOCE PR11 repeated cruises, the South Pacific Subtropical Mode Water (SPSTMW) has been identified in the region of the Tasman Front Extension (TFE) around 29?S to the east of Aus...From the synopical CTD sections in the WOCE PR11 repeated cruises, the South Pacific Subtropical Mode Water (SPSTMW) has been identified in the region of the Tasman Front Extension (TFE) around 29?S to the east of Australia. In the depth range of 150-250 m, the SPSTMW appears as a thermostad with vertical temperature gradient lower than 1.6℃(100 m)-1 and a tem- perature range of 16.5-19.5℃ and as a pycnostad with PV lower than 2×10-10 m-1 s-1 and a potential density range of 25.4-26.0 kg m-3. Like the subtropical mode waters in the North Atlantic and North Pacific, the formation of the SPSTMW is associated with the convective mixing during the austral wintertime as manifested from the time series of the Argo floats. And cold water entrains into the mixed layer with the deepening mixed layer from September to the middle of October. During the wintertime formation process, mesoscale eddies prevailing in the TFE region play an important role in the SPSTMW formation, and have a great effect on the SPSTMW distribution in the next year. The deeper (shallower) mixed layer in wintertime, consistent with the depressed (uplifted) permanent thermocline, is formed by the anticyclonic (cyclonic) eddies, and the substantial mode water thicker than 50 m is mainly found in the region of the anticyclonic eddies where the permanent thermocline is deeper than 450 m.展开更多
During the early Silurian, a transgressive and vast shallow sea with flat sea-floor covered the central Tarim Basin (the Tazhong area). The depositional environment of the middle member of the Kalpingtag Formation is ...During the early Silurian, a transgressive and vast shallow sea with flat sea-floor covered the central Tarim Basin (the Tazhong area). The depositional environment of the middle member of the Kalpingtag Formation is controversial. In order to provide a basis for the prediction of reservoir sand, the sedimentary facies are recognized according to abundant core observations and de- scriptions combined with well-log analysis, isograms, seismic interpretations and regional sedimentary background. The middle member of the Kalpingtag Formation, which shows a retrograding sequence, is interpreted as braid-delta deposits influenced by mi- nor tidal reworking. The sources of clasts are from the southern uplift. The subaqueous braid-delta deposits in the study area have some characteristics quite different from the common deltas that generally deposit in marginal seas. Four facies grouped to a delta front association are recognized, ranging from distributary-channel (Facies A), front bar (Facies B), sand sheet (Facies C) and inter- distributary bay (Facies D). The distributary channels construct the sandbody framework of the delta front. Front bar deposits, which are fine-grained with low depositional dips, display a near-continuous sand strip around the entire periphery of the delta. Sand sheet deposits are mainly found in front of Facies B, gradationally contacting with the prodelta. The interdistributary bay is essentially the uppermost unit capping the channel sequence and generally made up of laminated and massive mudstones. The delta front deposits display extensive sheet-like bodies contrasting with the characteristic wedge shapes of common subaqueous delta bodies. The bi- modal cross-stratification and mud drapes in the fine- to medium-grained sandstone in the distal area are inferred to reflect high-energy tidal processes.展开更多
The Patagonian Shelf is a very productive region with dif ferent ecosystem structures. A long history of fishing in the Southwestern Atlantic Ocean combined with a complex hydrographic structure, with a permanent fron...The Patagonian Shelf is a very productive region with dif ferent ecosystem structures. A long history of fishing in the Southwestern Atlantic Ocean combined with a complex hydrographic structure, with a permanent front over the shelf-break and dif ferent coastal frontal regions, and a wide non-frontal area in between have made the food web in this area more complex and have resulted in changes to the spatialtemporal scale. Stable isotopes of carbon and nitrogen were used to determine the trophic structure of the Patagonian shelf break which was previously poorly understood. The results indicated that the average δ^(15)N value of pelagic guild(I llex argentinus) was remarkable lower than those of the other guilds. The δ^(13)C values of almost all species ranged from-17‰ to-18‰, but S tromateus brasiliensis had a significant lower δ^(13)C value. Compared with the southern Patagonian shelf, short food chain length also occurred. The impact of complex oceanographic structures has resulted in food web structure change to the temporal-spatial scale on the Patagonian shelf. The Patagonian shelf break can be considered as a separated ecosystem structure with lower δ^(15)N values.展开更多
Rapid,high-throughput and reliable methods are urgently required to accurately detect and monitor harmful algae,which are responsible for algal blooms,such as red and green tides. In this study,we successfully develop...Rapid,high-throughput and reliable methods are urgently required to accurately detect and monitor harmful algae,which are responsible for algal blooms,such as red and green tides. In this study,we successfully developed a multiplex PCR-based DNA microarray method capable of detecting nine harmful algal species simultaneously,namely A lexandrium tamarense,Gyrodinium instriatum,Heterosigma akashiwo,Karenia mikimotoi,Prorocentrum donghaiense,Prorocentrum minimum,Ulva compressa,Ulva ohnoi and Ulva prolifera. This method achieved a limit of detection(LOD) of 0.5 ng of genomic DNA(orders of magnitude of the deci-nanogram range) in the tested algae cultures. Altogether,230 field samples from ship ballast waters and seaport waters were used to evaluate the DNA microarray. The clinical sensitivity and specificity of the DNA microarray assay in detecting field samples were 96.4% and 90.9%,respectively,relative to conventional morphological methods. This indicated that this high-throughput,automatic,and specific method is well suited for the detection of algae in water samples.展开更多
Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup is associated with harmful algal blooms in temperate and subtropical zones of the world. The hemolytic substances produced by K. mikimotoi are thought...Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup is associated with harmful algal blooms in temperate and subtropical zones of the world. The hemolytic substances produced by K. mikimotoi are thought to cause mortality in fishes and invertebrates. We evaluated the composition of the hemolytic toxin produced by K. mikimotoi cultured in the laboratory using thin-layer chromatography. In addition, we evaluated the effect of co-occuring algae (Prorocentrum donghaiense and Alexandrium tamarense) and the cladoceran grazer Moina mongoliea on hemolytic toxin production in K. mikimotoi. The hemolytic toxins from K. mikimotoi were a mixture of 2 liposaccharides and 1 lipid. Waterborne clues from P. donghaiense and A. tamarense inhibited the growth of K. mikimotoi but increased the production of hemolytic toxins. Conversely, K. mikimotoi strongly inhibited the growth of caged P. donghaiense and A. tamarense. In addition, the ingestion of K. mikimotoi by M. mongolica induced the production of hemolytic toxins in K. mikimotoi. Taken together, our results suggest that the presence of other microalgae and grazers may be as important as environmental factors for controlling the production of hemolytic substances. K. mikimotoi secreted allelochemicals other than unstable fatty acids with hemolytic activity. The production of hemolytic toxins in dinofiagellates was not only dependent on resource availability, but also on the risk of predation. Hemolytic toxins likely play an important role as chemical deterrents secreted by K. mikimotoi.展开更多
Recent advances in remote sensing technology and methods have resulted in the development of an evapotranspiration(ET) product from the Moderate Resolution Imaging Spectrometer(MOD16). The accuracy of this product how...Recent advances in remote sensing technology and methods have resulted in the development of an evapotranspiration(ET) product from the Moderate Resolution Imaging Spectrometer(MOD16). The accuracy of this product however has not been tested for coastal wetland ecosystems. The objective of this study therefore is to validate the MOD16 ET product using data from one eddy covariance flux tower situated in the Panjin coastal wetland ecosystem within the Liaohe River Delta, Northeast China. Cumulative ET data over an eight-day period in 2005 from the flux tower was calculated to coincide with the MOD16 products across the same period. Results showed that data from the flux tower were inconsistent with that gained form the MOD16 ET. In general, results from Panjin showed that there was an underestimation of MOD16 ET in the spring and fall, with Biases of -2.27 and -3.53 mm/8 d, respectively(–40.58% and -49.13% of the observed mean). Results for Bias during the summer had a range of 1.77 mm/8 d(7.82% of the observed mean), indicating an overestimation of MOD16 ET. According to the RMSE, summer(6.14 mm/8 d) achieved the lowest value, indicating low accuracy of the MOD16 ET product. However, RMSE(2.09 mm/8 d) in spring was the same as that in the fall. Relationship between ET and its relevant meteorological parameters were analyzed. Results indicated a very good relationship between surface air temperature and ET. Meanwhile a significant relationship between wind speed and ET also existed. The inconsistent comparison of MOD16 and flux tower-based ET are mainly attributed to the parameterization of the Penman-Monteith model, flux tower measurement errors, and flux tower footprint vs. MODIS pixels.展开更多
UMhlathuze River is the main recipient of domestic sewage, industrial as well as agricultural waste from local industrial and agricultural practices. It is the effluent "dumping sites" for most human activity practi...UMhlathuze River is the main recipient of domestic sewage, industrial as well as agricultural waste from local industrial and agricultural practices. It is the effluent "dumping sites" for most human activity practices. Contamination of UMhlathuze River by agricultural and industrial developments makes communities around UMhlathuze area susceptible to potential outbreaks of water-borne illnesses as well as the risk of ingesting carcinogenic substances. In establishment of the effect of human developments on the UMhlathuze River, four different sites representing different human activities were used for sampling along the river. Temperature and pH were monitored in siitu and were found to vary between 19-21℃and 6.2-7.8, respectively. Chemical oxygen demand (COD) was found to be higher in areas affected by both industrial and agricultural activities. Spectroquadrant Pharo 300 (Merck) was used for chemical analysis of water. Agricultural waste recipient area had high concentration of phosphate, ammonia and nitrate. Parts of the river receiving effluent from treated wastewater had high sulphide, nitrate and ammonia concentrations. Industrial areas had high concentration of heavy metals (e.g., aluminium). Microorganisms found in all sites included Escherichia coli and species of Salmonella, Shigella, Citrobacter, Serratia and Enterobacter, although their quantities differed from agricultural to industrial sites. There was a positive correlation between contamination levels and human activities which ascribe river pollution to activities around the area. Agricultural and industrial development activities practiced around UMhlathuze River have a huge contribution to the continued deterioration of the quality of water at UMhlathuze River.展开更多
A complete set of one-month Acoustic Doppler Profiler (ADP) current data at a station in the southern Yellow Sea (SYS) is analyzed using the rotary spectrum method. The results revealed different rotary properties bet...A complete set of one-month Acoustic Doppler Profiler (ADP) current data at a station in the southern Yellow Sea (SYS) is analyzed using the rotary spectrum method. The results revealed different rotary properties between barotropic and baroclinic tidal currents. The barotropic and baroclinic tidal currents rotate elliptically counter-clockwise and clockwise, respectively. Meanwhile, baroclinic bottom tidal currents are almost along-isobath. The baroclinic cross-isobath velocities attenuate quickly at the bottom, implying important effects of bottom topography on the cross-isobath motions.展开更多
基金This study was supported by the Chinese Natural Science Foundation of China(NSFC)(Nos.40276009 and 90411010)
文摘From the synopical CTD sections in the WOCE PR11 repeated cruises, the South Pacific Subtropical Mode Water (SPSTMW) has been identified in the region of the Tasman Front Extension (TFE) around 29?S to the east of Australia. In the depth range of 150-250 m, the SPSTMW appears as a thermostad with vertical temperature gradient lower than 1.6℃(100 m)-1 and a tem- perature range of 16.5-19.5℃ and as a pycnostad with PV lower than 2×10-10 m-1 s-1 and a potential density range of 25.4-26.0 kg m-3. Like the subtropical mode waters in the North Atlantic and North Pacific, the formation of the SPSTMW is associated with the convective mixing during the austral wintertime as manifested from the time series of the Argo floats. And cold water entrains into the mixed layer with the deepening mixed layer from September to the middle of October. During the wintertime formation process, mesoscale eddies prevailing in the TFE region play an important role in the SPSTMW formation, and have a great effect on the SPSTMW distribution in the next year. The deeper (shallower) mixed layer in wintertime, consistent with the depressed (uplifted) permanent thermocline, is formed by the anticyclonic (cyclonic) eddies, and the substantial mode water thicker than 50 m is mainly found in the region of the anticyclonic eddies where the permanent thermocline is deeper than 450 m.
文摘During the early Silurian, a transgressive and vast shallow sea with flat sea-floor covered the central Tarim Basin (the Tazhong area). The depositional environment of the middle member of the Kalpingtag Formation is controversial. In order to provide a basis for the prediction of reservoir sand, the sedimentary facies are recognized according to abundant core observations and de- scriptions combined with well-log analysis, isograms, seismic interpretations and regional sedimentary background. The middle member of the Kalpingtag Formation, which shows a retrograding sequence, is interpreted as braid-delta deposits influenced by mi- nor tidal reworking. The sources of clasts are from the southern uplift. The subaqueous braid-delta deposits in the study area have some characteristics quite different from the common deltas that generally deposit in marginal seas. Four facies grouped to a delta front association are recognized, ranging from distributary-channel (Facies A), front bar (Facies B), sand sheet (Facies C) and inter- distributary bay (Facies D). The distributary channels construct the sandbody framework of the delta front. Front bar deposits, which are fine-grained with low depositional dips, display a near-continuous sand strip around the entire periphery of the delta. Sand sheet deposits are mainly found in front of Facies B, gradationally contacting with the prodelta. The interdistributary bay is essentially the uppermost unit capping the channel sequence and generally made up of laminated and massive mudstones. The delta front deposits display extensive sheet-like bodies contrasting with the characteristic wedge shapes of common subaqueous delta bodies. The bi- modal cross-stratification and mud drapes in the fine- to medium-grained sandstone in the distal area are inferred to reflect high-energy tidal processes.
基金Supported by the National Key Technology R&D Program of China(No.2013BAD13B03)the National Natural Science Foundation of China(No.41776185)the Special Fund for Agro-Scientifi c Research in the Public Interest of China(No.201203018)
文摘The Patagonian Shelf is a very productive region with dif ferent ecosystem structures. A long history of fishing in the Southwestern Atlantic Ocean combined with a complex hydrographic structure, with a permanent front over the shelf-break and dif ferent coastal frontal regions, and a wide non-frontal area in between have made the food web in this area more complex and have resulted in changes to the spatialtemporal scale. Stable isotopes of carbon and nitrogen were used to determine the trophic structure of the Patagonian shelf break which was previously poorly understood. The results indicated that the average δ^(15)N value of pelagic guild(I llex argentinus) was remarkable lower than those of the other guilds. The δ^(13)C values of almost all species ranged from-17‰ to-18‰, but S tromateus brasiliensis had a significant lower δ^(13)C value. Compared with the southern Patagonian shelf, short food chain length also occurred. The impact of complex oceanographic structures has resulted in food web structure change to the temporal-spatial scale on the Patagonian shelf. The Patagonian shelf break can be considered as a separated ecosystem structure with lower δ^(15)N values.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA092001)the Science and Technology Project of Zhejiang Province(No.2013C03045-1)+2 种基金the Zhejiang Marine Biotechnology Innovation Team(No.2010R50029-12)the Natural Science Foundation of Ningbo City of China(No.2013A610168)the KC Wong Magna Fund in Ningbo University
文摘Rapid,high-throughput and reliable methods are urgently required to accurately detect and monitor harmful algae,which are responsible for algal blooms,such as red and green tides. In this study,we successfully developed a multiplex PCR-based DNA microarray method capable of detecting nine harmful algal species simultaneously,namely A lexandrium tamarense,Gyrodinium instriatum,Heterosigma akashiwo,Karenia mikimotoi,Prorocentrum donghaiense,Prorocentrum minimum,Ulva compressa,Ulva ohnoi and Ulva prolifera. This method achieved a limit of detection(LOD) of 0.5 ng of genomic DNA(orders of magnitude of the deci-nanogram range) in the tested algae cultures. Altogether,230 field samples from ship ballast waters and seaport waters were used to evaluate the DNA microarray. The clinical sensitivity and specificity of the DNA microarray assay in detecting field samples were 96.4% and 90.9%,respectively,relative to conventional morphological methods. This indicated that this high-throughput,automatic,and specific method is well suited for the detection of algae in water samples.
基金Supported by the National Natural Science Foundation of China(Nos.30970502,U0733006)the National Basic Research Program of China(973 Program)(No.2010CB428702)
文摘Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup is associated with harmful algal blooms in temperate and subtropical zones of the world. The hemolytic substances produced by K. mikimotoi are thought to cause mortality in fishes and invertebrates. We evaluated the composition of the hemolytic toxin produced by K. mikimotoi cultured in the laboratory using thin-layer chromatography. In addition, we evaluated the effect of co-occuring algae (Prorocentrum donghaiense and Alexandrium tamarense) and the cladoceran grazer Moina mongoliea on hemolytic toxin production in K. mikimotoi. The hemolytic toxins from K. mikimotoi were a mixture of 2 liposaccharides and 1 lipid. Waterborne clues from P. donghaiense and A. tamarense inhibited the growth of K. mikimotoi but increased the production of hemolytic toxins. Conversely, K. mikimotoi strongly inhibited the growth of caged P. donghaiense and A. tamarense. In addition, the ingestion of K. mikimotoi by M. mongolica induced the production of hemolytic toxins in K. mikimotoi. Taken together, our results suggest that the presence of other microalgae and grazers may be as important as environmental factors for controlling the production of hemolytic substances. K. mikimotoi secreted allelochemicals other than unstable fatty acids with hemolytic activity. The production of hemolytic toxins in dinofiagellates was not only dependent on resource availability, but also on the risk of predation. Hemolytic toxins likely play an important role as chemical deterrents secreted by K. mikimotoi.
基金Under the auspices of National Key R&D Program of China(No.2016YFA0602301-1)National Key Research Project(No.2013CB430401)
文摘Recent advances in remote sensing technology and methods have resulted in the development of an evapotranspiration(ET) product from the Moderate Resolution Imaging Spectrometer(MOD16). The accuracy of this product however has not been tested for coastal wetland ecosystems. The objective of this study therefore is to validate the MOD16 ET product using data from one eddy covariance flux tower situated in the Panjin coastal wetland ecosystem within the Liaohe River Delta, Northeast China. Cumulative ET data over an eight-day period in 2005 from the flux tower was calculated to coincide with the MOD16 products across the same period. Results showed that data from the flux tower were inconsistent with that gained form the MOD16 ET. In general, results from Panjin showed that there was an underestimation of MOD16 ET in the spring and fall, with Biases of -2.27 and -3.53 mm/8 d, respectively(–40.58% and -49.13% of the observed mean). Results for Bias during the summer had a range of 1.77 mm/8 d(7.82% of the observed mean), indicating an overestimation of MOD16 ET. According to the RMSE, summer(6.14 mm/8 d) achieved the lowest value, indicating low accuracy of the MOD16 ET product. However, RMSE(2.09 mm/8 d) in spring was the same as that in the fall. Relationship between ET and its relevant meteorological parameters were analyzed. Results indicated a very good relationship between surface air temperature and ET. Meanwhile a significant relationship between wind speed and ET also existed. The inconsistent comparison of MOD16 and flux tower-based ET are mainly attributed to the parameterization of the Penman-Monteith model, flux tower measurement errors, and flux tower footprint vs. MODIS pixels.
文摘UMhlathuze River is the main recipient of domestic sewage, industrial as well as agricultural waste from local industrial and agricultural practices. It is the effluent "dumping sites" for most human activity practices. Contamination of UMhlathuze River by agricultural and industrial developments makes communities around UMhlathuze area susceptible to potential outbreaks of water-borne illnesses as well as the risk of ingesting carcinogenic substances. In establishment of the effect of human developments on the UMhlathuze River, four different sites representing different human activities were used for sampling along the river. Temperature and pH were monitored in siitu and were found to vary between 19-21℃and 6.2-7.8, respectively. Chemical oxygen demand (COD) was found to be higher in areas affected by both industrial and agricultural activities. Spectroquadrant Pharo 300 (Merck) was used for chemical analysis of water. Agricultural waste recipient area had high concentration of phosphate, ammonia and nitrate. Parts of the river receiving effluent from treated wastewater had high sulphide, nitrate and ammonia concentrations. Industrial areas had high concentration of heavy metals (e.g., aluminium). Microorganisms found in all sites included Escherichia coli and species of Salmonella, Shigella, Citrobacter, Serratia and Enterobacter, although their quantities differed from agricultural to industrial sites. There was a positive correlation between contamination levels and human activities which ascribe river pollution to activities around the area. Agricultural and industrial development activities practiced around UMhlathuze River have a huge contribution to the continued deterioration of the quality of water at UMhlathuze River.
基金This work is supported by the National Natural Science Foundation of China (No. 40606009)the special Post-doctoral research Foundation of Shandong Province (No. 200602002).
文摘A complete set of one-month Acoustic Doppler Profiler (ADP) current data at a station in the southern Yellow Sea (SYS) is analyzed using the rotary spectrum method. The results revealed different rotary properties between barotropic and baroclinic tidal currents. The barotropic and baroclinic tidal currents rotate elliptically counter-clockwise and clockwise, respectively. Meanwhile, baroclinic bottom tidal currents are almost along-isobath. The baroclinic cross-isobath velocities attenuate quickly at the bottom, implying important effects of bottom topography on the cross-isobath motions.