2005 Vol. 27, No. 6
Display Method:
2005, 27(6): 1-8.
Abstract:
The South China Sea (SCS) has a complex energetic circulation,especially at its northern part.Three major factors contributing to a generally cyclonic gyre in the upper ocean of the northern SCS areidentified:(1) monsoonal wind forcing;(2) net water transport into the SCS through the Luzon Strait;(3) vorticity advection from the Kuroshio.The intensified western boundary current of the cyclonic gyre,called the "Dongsha Current" in this paper,flows southwest ward next to the shelf south of China.It extends all the way south in winter and reaches central Vietnam in summer.Every year around 10 meso-scale eddies are present in the SCS.Strong wind-stress curl from orographic effects is likely responsible for their generation.Vorticity advection from the Kuroshio can also induce meso-scale eddies.Available hydrogra-phic data do not support the notion that the Kuroshio water enters the South China Sea as a "branch" current,nor primarily as meso-scale eddies.More likely,the Kuroshio water enters the South China Sea principally during the winter monsoon through sub-mesoscale processes confined in the surface layer.
The South China Sea (SCS) has a complex energetic circulation,especially at its northern part.Three major factors contributing to a generally cyclonic gyre in the upper ocean of the northern SCS areidentified:(1) monsoonal wind forcing;(2) net water transport into the SCS through the Luzon Strait;(3) vorticity advection from the Kuroshio.The intensified western boundary current of the cyclonic gyre,called the "Dongsha Current" in this paper,flows southwest ward next to the shelf south of China.It extends all the way south in winter and reaches central Vietnam in summer.Every year around 10 meso-scale eddies are present in the SCS.Strong wind-stress curl from orographic effects is likely responsible for their generation.Vorticity advection from the Kuroshio can also induce meso-scale eddies.Available hydrogra-phic data do not support the notion that the Kuroshio water enters the South China Sea as a "branch" current,nor primarily as meso-scale eddies.More likely,the Kuroshio water enters the South China Sea principally during the winter monsoon through sub-mesoscale processes confined in the surface layer.
2005, 27(6): 9-15.
Abstract:
The temperature and salinity profiles of the ARGO floats in the warm pool of the northwestern Pacific were analyzed.The results show that when typho on passes,the sea surface salinity (SSS) usually decreases in mosto bservations,which is in contrast with that of the observations from the Atlantic Ocean where the SSS usually increases when hurricane passes.This is related to the typical thermal structure in this warm pool region and the differences between the precipitation processes associated with the typhoon in the two oceans.The result is of importance to the study of the heat exchange proceeses and the mixing of the mixed layer in the warm pool of the northwestern Pacific.
The temperature and salinity profiles of the ARGO floats in the warm pool of the northwestern Pacific were analyzed.The results show that when typho on passes,the sea surface salinity (SSS) usually decreases in mosto bservations,which is in contrast with that of the observations from the Atlantic Ocean where the SSS usually increases when hurricane passes.This is related to the typical thermal structure in this warm pool region and the differences between the precipitation processes associated with the typhoon in the two oceans.The result is of importance to the study of the heat exchange proceeses and the mixing of the mixed layer in the warm pool of the northwestern Pacific.
2005, 27(6): 16-25.
Abstract:
The impact of TRMM/TMI surface rainfall rate (SRR) 4DVAR on numerical simulation of TC Danas (2001) is studied.Several numerical experiments are performed with mesoscale model MM5 to in vestigate the development of Danas from TC genesis to a typhoon.Under the dynamic constraint of MM5 model,the SRR data are assimilated directly in the initial meteorological field (18 km).The direct assimilation of SRR data with MM5 4DVAR is proved to be feasible,which not only incorporate as many observation data available as possible but also avoid the resultant error due to the twice cycles of assimilation (1DVAR+4DVAR).On the basis of adjusting the initial fields (SLP,temperature,humidity and soon),the direct assimilation of TRMM SRR improves the description of TC structure (such as warm core,vorticity and divergence) and the prediction of rainfall.As a result,the intensity and track of Danas are simulated successfully with TR M SRR assimilation.
The impact of TRMM/TMI surface rainfall rate (SRR) 4DVAR on numerical simulation of TC Danas (2001) is studied.Several numerical experiments are performed with mesoscale model MM5 to in vestigate the development of Danas from TC genesis to a typhoon.Under the dynamic constraint of MM5 model,the SRR data are assimilated directly in the initial meteorological field (18 km).The direct assimilation of SRR data with MM5 4DVAR is proved to be feasible,which not only incorporate as many observation data available as possible but also avoid the resultant error due to the twice cycles of assimilation (1DVAR+4DVAR).On the basis of adjusting the initial fields (SLP,temperature,humidity and soon),the direct assimilation of TRMM SRR improves the description of TC structure (such as warm core,vorticity and divergence) and the prediction of rainfall.As a result,the intensity and track of Danas are simulated successfully with TR M SRR assimilation.
2005, 27(6): 26-29.
Abstract:
The uncertainty of phosphate measurement in offshore water in the East China Sea was studied with the general method.By analyzing the effective factors of measurement uncertainty,such as the specific measurement environment,the standard materials used,the sampling volume,mole quality,etc.,the standard uncertainty,the combined standard uncertainty and the extended uncertainty of phosphate measurement were estimated.The results show that the specific measurement environment is the main fluencing factor of measurement uncertainty of phosphate,and the relative combined standard uncertainty of phosphate in the offshore water in the East China Sea is about 0.067.
The uncertainty of phosphate measurement in offshore water in the East China Sea was studied with the general method.By analyzing the effective factors of measurement uncertainty,such as the specific measurement environment,the standard materials used,the sampling volume,mole quality,etc.,the standard uncertainty,the combined standard uncertainty and the extended uncertainty of phosphate measurement were estimated.The results show that the specific measurement environment is the main fluencing factor of measurement uncertainty of phosphate,and the relative combined standard uncertainty of phosphate in the offshore water in the East China Sea is about 0.067.
2005, 27(6): 30-37.
Abstract:
During "TOGA" and "China-Japan joint investigation of the subtropical circulation",the total dissolved carbon dioxide in surface and deep water and sea-air partial pressure of carbon dioxide in surface and deep water were measured in November 1986 and June 1996 with the coulometer and gas chromatography systems.The distribution and variation of the sources and sinks of carbon dioxide on the basis of the data of carbon dioxide partial pressure value in air (A) and carbon dioxide partial pressure value in the surface water were measured during the 14 cruises "TOGA" and "China-Japan joint investigation of the subtropical circulation".The carbon dioxide partial pressure value in the surface water observed over the equatorial area,5°N~5°S and 130°~165°E,exceed the carbon dioxide partial pressure value in air by 1.5 to 4.5 Pa,indicating that in this area there is a source of atmospheric carbon dioxide.These values are much smaller than those of up to +9.1 Pa observed in the central equatorial Pacific and those of up to +15 Pa observed in the eastern equatorial Pacific.It appears,therefore,that the intensity of the oceanic carbon dioxide source decreases westward.In autumnt here is a stronger source and in spring there is a sink for atmospheric carbon dioxide,in the subtropical circulation.On the basis of nine cruises of carbon dioxide data in surface and deep water measured,major factors temperature and salinity influencing carbon dioxide in seaw ater were discussed,the distribution and variation of carbon dioxide may berelated to the current,wAter mass,Kuroshio and ENSO.
During "TOGA" and "China-Japan joint investigation of the subtropical circulation",the total dissolved carbon dioxide in surface and deep water and sea-air partial pressure of carbon dioxide in surface and deep water were measured in November 1986 and June 1996 with the coulometer and gas chromatography systems.The distribution and variation of the sources and sinks of carbon dioxide on the basis of the data of carbon dioxide partial pressure value in air (A) and carbon dioxide partial pressure value in the surface water were measured during the 14 cruises "TOGA" and "China-Japan joint investigation of the subtropical circulation".The carbon dioxide partial pressure value in the surface water observed over the equatorial area,5°N~5°S and 130°~165°E,exceed the carbon dioxide partial pressure value in air by 1.5 to 4.5 Pa,indicating that in this area there is a source of atmospheric carbon dioxide.These values are much smaller than those of up to +9.1 Pa observed in the central equatorial Pacific and those of up to +15 Pa observed in the eastern equatorial Pacific.It appears,therefore,that the intensity of the oceanic carbon dioxide source decreases westward.In autumnt here is a stronger source and in spring there is a sink for atmospheric carbon dioxide,in the subtropical circulation.On the basis of nine cruises of carbon dioxide data in surface and deep water measured,major factors temperature and salinity influencing carbon dioxide in seaw ater were discussed,the distribution and variation of carbon dioxide may berelated to the current,wAter mass,Kuroshio and ENSO.
2005, 27(6): 38-45.
Abstract:
A study about biogenic elements on vertical transition profile in wInter and summer and data of time series sediment trap in the north of the South China Sea shows that particulate matter in that place mainly comprises biogenic carbonate,biogenic silica,organic matter and lithogenic matter,particulate matterflux is about 90.0 mg/(m2·d) at 1 000 m.The study also reveals most particulate organic carbon is dissolved before being buried in sediments,so organic carbon in sediments mainly comefrom lateral transition and contribution of vertical transition is limited.Comparing with open ocean of the East Pacific Ocean,the margin sea is more sensitive to the variety of season,furthermore,the investigated place of the East Pacific Ocean is located in the tropic equator with high production,obvioUs biologic effect makes biologic respiration and substantial transfer activ likewise.
A study about biogenic elements on vertical transition profile in wInter and summer and data of time series sediment trap in the north of the South China Sea shows that particulate matter in that place mainly comprises biogenic carbonate,biogenic silica,organic matter and lithogenic matter,particulate matterflux is about 90.0 mg/(m2·d) at 1 000 m.The study also reveals most particulate organic carbon is dissolved before being buried in sediments,so organic carbon in sediments mainly comefrom lateral transition and contribution of vertical transition is limited.Comparing with open ocean of the East Pacific Ocean,the margin sea is more sensitive to the variety of season,furthermore,the investigated place of the East Pacific Ocean is located in the tropic equator with high production,obvioUs biologic effect makes biologic respiration and substantial transfer activ likewise.
2005, 27(6): 46-55.
Abstract:
The discuss on the topographical environment characteristics of typical modern marine hydrothermal activity regions will be helpful to increase understanding of the modern hydrothermal activity,the distribution rules of its mineral resources and the forming causes and mechanism,etc.The three-dimensional topography figures of major typical hydrothermal regions are drawn on the basis of fielD-measured bathymetric data of the Okinawa Trough and collecting a large number of data on bathymetry,multibeam and seismic profiles of other major typical hydrothermal regions.Through the systematic analysis and contraststudies on topographical environment characteristics of these typical regions,it is found that the hydrothermal activity only occurs under the circumstance of the particular topographical environment,though it distributes widely in the tensional tectonic environment,for inst ance,t he mid-ocean ridges,transform faults zones,back-arc spreading basins and the modern marine craters regions.
The discuss on the topographical environment characteristics of typical modern marine hydrothermal activity regions will be helpful to increase understanding of the modern hydrothermal activity,the distribution rules of its mineral resources and the forming causes and mechanism,etc.The three-dimensional topography figures of major typical hydrothermal regions are drawn on the basis of fielD-measured bathymetric data of the Okinawa Trough and collecting a large number of data on bathymetry,multibeam and seismic profiles of other major typical hydrothermal regions.Through the systematic analysis and contraststudies on topographical environment characteristics of these typical regions,it is found that the hydrothermal activity only occurs under the circumstance of the particular topographical environment,though it distributes widely in the tensional tectonic environment,for inst ance,t he mid-ocean ridges,transform faults zones,back-arc spreading basins and the modern marine craters regions.
2005, 27(6): 56-64.
Abstract:
A detailed rock magnetic investigation was undertaken at 2~4 cm interval for the long core CSH1 (17.36 m) from the northern Okinawa T rough.A time scale of the core was constructed by two characteristic tephras and foraminferal assemblages,indicating an age of 50 ka for the bottom of the core.Except for three tephr as and abrupt decrease in surface,there are little changes in all kinds of rock magnetic parameters that can be correlated to the climate change for the last 50 ka.Being different from the common sediments,most of S value (S= -IRM-0.3T/SIRM) for the sediments are smaller than 0.9,which implies substantial amount of magnetic minerals with high coercivity.Representative susceptibility-temperature (K-T) curves show 200~350℃ Curie temperature in addition to 580℃ of magnetite which reveals the existence of iron sulphide (greigite or pyrrhotite).This is also consistent with awful smell during heating and dark heating product which indicates the existence of iron sulphide.Both the occurrence of authigenic iron sulphide and quick decrease of magnetic parameters at the surface clearly show that sediments from Core CSH1 have undergone early diagenesis.The featureless magnetic changes of the whole core except for the three tephras mean that the postdepositonal alteration is so strong that most original signals have been destroyed.For the same reason,the organic matter in sediment and sulphate in pore water have been consumed,and iron,manganese dissolution and precipitation happen during the redox processes.Great caution must be taken when using these altered chemical parameters for the interpretation of climatic changes.
A detailed rock magnetic investigation was undertaken at 2~4 cm interval for the long core CSH1 (17.36 m) from the northern Okinawa T rough.A time scale of the core was constructed by two characteristic tephras and foraminferal assemblages,indicating an age of 50 ka for the bottom of the core.Except for three tephr as and abrupt decrease in surface,there are little changes in all kinds of rock magnetic parameters that can be correlated to the climate change for the last 50 ka.Being different from the common sediments,most of S value (S= -IRM-0.3T/SIRM) for the sediments are smaller than 0.9,which implies substantial amount of magnetic minerals with high coercivity.Representative susceptibility-temperature (K-T) curves show 200~350℃ Curie temperature in addition to 580℃ of magnetite which reveals the existence of iron sulphide (greigite or pyrrhotite).This is also consistent with awful smell during heating and dark heating product which indicates the existence of iron sulphide.Both the occurrence of authigenic iron sulphide and quick decrease of magnetic parameters at the surface clearly show that sediments from Core CSH1 have undergone early diagenesis.The featureless magnetic changes of the whole core except for the three tephras mean that the postdepositonal alteration is so strong that most original signals have been destroyed.For the same reason,the organic matter in sediment and sulphate in pore water have been consumed,and iron,manganese dissolution and precipitation happen during the redox processes.Great caution must be taken when using these altered chemical parameters for the interpretation of climatic changes.
2005, 27(6): 65-74.
Abstract:
The results of an analysis of molluscan remains collected from the Chukchi Sea,the Beaufort Sea and the Bering Sea during the first Chinese national arctic research expedition,from July to September 1999.Seventeen species of molluscs have been identified,and they belong to two classes:Bivalvia and Gastropoda.The compositions of Mollusca from the above mentioned areas are very simple.According to the distribution pattern,among the molluscan species two groups may be distinguished.The panarctic and circumboreal group comprises A starte montagui,Liocymaf luctuosa,Macoma calcarea,M.moestaalas-kana,Mya pseudoarenaria,Nuculana pernula,N.radiata,Nucula bellotii,Seripes groenlandicus and Turritellapolaris.Three species,Argobuccinum oregonense,Cyclocardiacrebri costata and Trichotroiscoronata are components of the panarctic and Pacific boreal group.With regard to feeding habits,detritus feeders dominate.There are seven species of detritus feeders,i.e.,Macomacalcarea,M.moestaal askana,Macoma sp.,Nuculana pernula,N.radiata,Nucula bellotii and Trichotropis coronata.Detritus feeders are dominant with regard to the numbers of species as well as to the occurrence frequency.Macomacal carea is the most abundant species.
The results of an analysis of molluscan remains collected from the Chukchi Sea,the Beaufort Sea and the Bering Sea during the first Chinese national arctic research expedition,from July to September 1999.Seventeen species of molluscs have been identified,and they belong to two classes:Bivalvia and Gastropoda.The compositions of Mollusca from the above mentioned areas are very simple.According to the distribution pattern,among the molluscan species two groups may be distinguished.The panarctic and circumboreal group comprises A starte montagui,Liocymaf luctuosa,Macoma calcarea,M.moestaalas-kana,Mya pseudoarenaria,Nuculana pernula,N.radiata,Nucula bellotii,Seripes groenlandicus and Turritellapolaris.Three species,Argobuccinum oregonense,Cyclocardiacrebri costata and Trichotroiscoronata are components of the panarctic and Pacific boreal group.With regard to feeding habits,detritus feeders dominate.There are seven species of detritus feeders,i.e.,Macomacalcarea,M.moestaal askana,Macoma sp.,Nuculana pernula,N.radiata,Nucula bellotii and Trichotropis coronata.Detritus feeders are dominant with regard to the numbers of species as well as to the occurrence frequency.Macomacal carea is the most abundant species.
2005, 27(6): 75-82.
Abstract:
On the basis of the measurements of current velocities and suspended sediment concentrations within a tidal creek,together with analysis of surficial sediment samples collected from the creek and the adjacent Sueada salsa flats on 27 and 29 July 2002,at Wang gang,Jiangsu coast,characteristics of water and suspended sediment transport rates within the creek and the relationship between suspended and seabed sediments were analyzed.The results show that there is remarkable flood-ebb time-asymmetry for the tidal current,with variations in the suspended sediment concent ration and the rate of water/sediment transport.The marsh surface supplied water quantity accounts for 33% of the ebb water quantity in the creek,resulting in 20% of the ebb suspended sediment discharge in the creek during the ebb.This is a basic influence on the time asymmetry.Consequently,within a tidal cycle,the net water and suspended sediment discharges in the creek are opposite to those for the marsh surface,i.e.,they dominated.Silt and clay are the dominant components of the suspended and seabed sediments,accounting for more than 95% uri.The difference in grain size distribution between the suspended sediment within the creek and the bed sedimenton the adjacent marsh surface is very small.Variations in the suspended sediment concentration during the tidal cycle show that a substantive amount of the suspended sediments settles onto the marsh surface;the suspended sediments are the major source of seabed sediments.Therefore,the grain size distributions of seabed and suspended sediments are very close and there is a good exponential relationship between the grain size and the ratio of the content of the component associated with the grain size in the seabed sediment to that in the suspended sediment.
On the basis of the measurements of current velocities and suspended sediment concentrations within a tidal creek,together with analysis of surficial sediment samples collected from the creek and the adjacent Sueada salsa flats on 27 and 29 July 2002,at Wang gang,Jiangsu coast,characteristics of water and suspended sediment transport rates within the creek and the relationship between suspended and seabed sediments were analyzed.The results show that there is remarkable flood-ebb time-asymmetry for the tidal current,with variations in the suspended sediment concent ration and the rate of water/sediment transport.The marsh surface supplied water quantity accounts for 33% of the ebb water quantity in the creek,resulting in 20% of the ebb suspended sediment discharge in the creek during the ebb.This is a basic influence on the time asymmetry.Consequently,within a tidal cycle,the net water and suspended sediment discharges in the creek are opposite to those for the marsh surface,i.e.,they dominated.Silt and clay are the dominant components of the suspended and seabed sediments,accounting for more than 95% uri.The difference in grain size distribution between the suspended sediment within the creek and the bed sedimenton the adjacent marsh surface is very small.Variations in the suspended sediment concentration during the tidal cycle show that a substantive amount of the suspended sediments settles onto the marsh surface;the suspended sediments are the major source of seabed sediments.Therefore,the grain size distributions of seabed and suspended sediments are very close and there is a good exponential relationship between the grain size and the ratio of the content of the component associated with the grain size in the seabed sediment to that in the suspended sediment.
2005, 27(6): 83-92.
Abstract:
Samples of Anthomedusae were collected from the Minnan-Taiwan Bank fishing gound upwelling region,the Luoyuan Bay,varied island waters of Fujian during 1985~2001.Through the examination of samples,Seven new species are found:Bougainvillia longistyla n.sp.,Koellikerina staurogaster n.sp.,Nubiella atentaculata n.sp.,Leuckartiara jianyinensis n.sp.,L.neustona n.sp.,Halitiara obtusus n.sp.and Halitiarella apicea n.sp.,and two new combination,i.e.,Mergaminutum (Xu,Huang and Chen,1991.) transl.nov.and Zanclea macrocystae (Xu,Huang and Chen,1991) transl.no v.An additional Teissiera polypofera Xu,Huang and Chen,1991 is redescribed and its position of taxonomy is discussed.Other add figure of medusa-buds on the stomach to Euphysittapyramidata (Kramp,1955).
Samples of Anthomedusae were collected from the Minnan-Taiwan Bank fishing gound upwelling region,the Luoyuan Bay,varied island waters of Fujian during 1985~2001.Through the examination of samples,Seven new species are found:Bougainvillia longistyla n.sp.,Koellikerina staurogaster n.sp.,Nubiella atentaculata n.sp.,Leuckartiara jianyinensis n.sp.,L.neustona n.sp.,Halitiara obtusus n.sp.and Halitiarella apicea n.sp.,and two new combination,i.e.,Mergaminutum (Xu,Huang and Chen,1991.) transl.nov.and Zanclea macrocystae (Xu,Huang and Chen,1991) transl.no v.An additional Teissiera polypofera Xu,Huang and Chen,1991 is redescribed and its position of taxonomy is discussed.Other add figure of medusa-buds on the stomach to Euphysittapyramidata (Kramp,1955).
2005, 27(6): 93-99.
Abstract:
On the basis of taxonomy of genus Trichiurus and length frequency data collected by traw l survey in the northern South China Sea,growth and mortality parameters for three species of Trichiurus were estimated.For T.haumela,T.nanhaiensis and T.brevis,the asymptotic anus lengths estim ated with ELEFANⅠ in von Bert alanffy growth function were separately 70.0,54.5 and 48.0 cm,growth rates 0.27,0.27 and 0.17,and initial condition parameter was -0.60,-0.68 and -1.10 a.Total mortality coefficients for the three speciesest imated by length-converted catch curves were 3.02,0.80 and 2.43,natural mortality coefficients by the Pauly empirical formula 0.39,0.58 and 0.44,and fishing mortality coefficients 2.63,0.22 and 1.99 respectively.Dynamic pool models indicated that exploitation of the stocks was unrational due to catches of large proportions of 0-age-group juveniles,although the stocks could sustain high fishing pressure.It is suggested that,for T.haumela,T.nanhaiensis and T.brevis,the ages at the first capture is increased to 3.0 ages (44 cm in anus length),2.0 ages (28 cm in anus length) and 2.7 ages (23 cm in anus length) respectively.
On the basis of taxonomy of genus Trichiurus and length frequency data collected by traw l survey in the northern South China Sea,growth and mortality parameters for three species of Trichiurus were estimated.For T.haumela,T.nanhaiensis and T.brevis,the asymptotic anus lengths estim ated with ELEFANⅠ in von Bert alanffy growth function were separately 70.0,54.5 and 48.0 cm,growth rates 0.27,0.27 and 0.17,and initial condition parameter was -0.60,-0.68 and -1.10 a.Total mortality coefficients for the three speciesest imated by length-converted catch curves were 3.02,0.80 and 2.43,natural mortality coefficients by the Pauly empirical formula 0.39,0.58 and 0.44,and fishing mortality coefficients 2.63,0.22 and 1.99 respectively.Dynamic pool models indicated that exploitation of the stocks was unrational due to catches of large proportions of 0-age-group juveniles,although the stocks could sustain high fishing pressure.It is suggested that,for T.haumela,T.nanhaiensis and T.brevis,the ages at the first capture is increased to 3.0 ages (44 cm in anus length),2.0 ages (28 cm in anus length) and 2.7 ages (23 cm in anus length) respectively.
2005, 27(6): 100-106.
Abstract:
The species composition and distribution of polycystine radiolarians in the plankton from the northern South China Sea are analyzed based on the samples collected with Judy net by the natioanl comprehensive oceanographic survey of China in 1959 from 128 stations.Two hundred and twelve species belonging to the orders Spumellaria and Nassellaria are identified,in which,145 species (68%) are members of Spumellaria,and 67 species (32%) belong to Nassellaria,and most of them are warm-water species.The species and individual number of Spum ellaria are much more than those of Nassellaria in the area.Four species,i.e.,Spongosphaera strep tacantha Haeckel,Pterocorys camp anula Haeckel,Ommatartus tetrathalamus tetrathalamus Haeckel,and Triastrum aurivillii Cleve,are considered as dominant species,by their ranges and the individual proportion in the total individual number (more than 3%).The results show the variation of radiolarian distribution pattern seaso nally.The individual density and distribution range of radiolarians are the lowest and the narrowest in January and Febr uary;the abundance increases from March,the density reaches the highest in A pril and remains in May and June,and f orms several high density cent res;the density decreases f rom July and August to December.That is to say,radiolarians breed largely and are abundant in late spring and summer,then the populations of species reduce in autumn and become down to the lowest in winter.The results also imply that the abundance and species diversity of poly cystine radiolarians enhance from coast to open sea gradually.This distribution pattern is affected by the water currents,temperature,salinity,and depth.
The species composition and distribution of polycystine radiolarians in the plankton from the northern South China Sea are analyzed based on the samples collected with Judy net by the natioanl comprehensive oceanographic survey of China in 1959 from 128 stations.Two hundred and twelve species belonging to the orders Spumellaria and Nassellaria are identified,in which,145 species (68%) are members of Spumellaria,and 67 species (32%) belong to Nassellaria,and most of them are warm-water species.The species and individual number of Spum ellaria are much more than those of Nassellaria in the area.Four species,i.e.,Spongosphaera strep tacantha Haeckel,Pterocorys camp anula Haeckel,Ommatartus tetrathalamus tetrathalamus Haeckel,and Triastrum aurivillii Cleve,are considered as dominant species,by their ranges and the individual proportion in the total individual number (more than 3%).The results show the variation of radiolarian distribution pattern seaso nally.The individual density and distribution range of radiolarians are the lowest and the narrowest in January and Febr uary;the abundance increases from March,the density reaches the highest in A pril and remains in May and June,and f orms several high density cent res;the density decreases f rom July and August to December.That is to say,radiolarians breed largely and are abundant in late spring and summer,then the populations of species reduce in autumn and become down to the lowest in winter.The results also imply that the abundance and species diversity of poly cystine radiolarians enhance from coast to open sea gradually.This distribution pattern is affected by the water currents,temperature,salinity,and depth.
2005, 27(6): 107-115.
Abstract:
An investigation was carried out in the Huanghai Sea and the East China Sea to reveal the quantitative relationship between the density of flagellates and suspended paticles in the summer of 2001.The results show that the density of flagellates varies from 44 to 12 600 ind./cm3,which can reach a large percentage of the suspended particles.The spectra of the suspended particles can be divided into four types as follow:flat spectra,humped spectra,plankton spectra,and mixed spectra.The density of flagellates va-ries in proportion to that of the suspended particles.As a whole,the correlation between flagellates and the suspended particles is obvious,and more characteristics are showed in different types of spectra.The relationship is discussed,hoping for exploring a new approach for the estimation of flagellate abundance in the sea.
An investigation was carried out in the Huanghai Sea and the East China Sea to reveal the quantitative relationship between the density of flagellates and suspended paticles in the summer of 2001.The results show that the density of flagellates varies from 44 to 12 600 ind./cm3,which can reach a large percentage of the suspended particles.The spectra of the suspended particles can be divided into four types as follow:flat spectra,humped spectra,plankton spectra,and mixed spectra.The density of flagellates va-ries in proportion to that of the suspended particles.As a whole,the correlation between flagellates and the suspended particles is obvious,and more characteristics are showed in different types of spectra.The relationship is discussed,hoping for exploring a new approach for the estimation of flagellate abundance in the sea.
2005, 27(6): 116-122.
Abstract:
It was undertaken (2003~2004) to investigate the distribution of arsenic concentrations in five culture-shellfish from the southern coast of Fujian Province,China.The results show that total arsenic concentrations in the five culture-shellfish vary from 0.65×10-6 to 4.80×10-6,with an overall average of 2.09×10-6.The percent of organic arsenic content to the total arsenic one ranges from 61.6% to 98.2%,and the percent of inorganic arsenic is from 2.3% to 38.4%.Their average values are 88.8% and 11.2% respectively.Difference of the inter-specific distribution of the total average concentration in the culture shellfish is little in the same culture area.Overall,the total arsenic average concentration of culture-benthic shellfish in sea beach soil is higher than that of raft-culture shellfish in shallow sea.The total arsenic concentrations in the five culture-shellfish in the Quanzhou Bay,the Meizhou Bay,the Dongshan Bay and the Jiulong Estuary are high,the Weitou Bay and the Zhao'an Bay are low,and in other bays are nearly the same.The pollution index of the inorganic arsenic ranges from 0.05 to 0.76 with an overall average of 0.23.And for the total arsenic,the pollution index is from 0.06~0.48 with an overall average of 0.21.They are all below the arsenics limit of natural food sanitation quality criteria in marine bivalve.The correlation between the total arsenic in the culture-shellfish and its length is overall positive.
It was undertaken (2003~2004) to investigate the distribution of arsenic concentrations in five culture-shellfish from the southern coast of Fujian Province,China.The results show that total arsenic concentrations in the five culture-shellfish vary from 0.65×10-6 to 4.80×10-6,with an overall average of 2.09×10-6.The percent of organic arsenic content to the total arsenic one ranges from 61.6% to 98.2%,and the percent of inorganic arsenic is from 2.3% to 38.4%.Their average values are 88.8% and 11.2% respectively.Difference of the inter-specific distribution of the total average concentration in the culture shellfish is little in the same culture area.Overall,the total arsenic average concentration of culture-benthic shellfish in sea beach soil is higher than that of raft-culture shellfish in shallow sea.The total arsenic concentrations in the five culture-shellfish in the Quanzhou Bay,the Meizhou Bay,the Dongshan Bay and the Jiulong Estuary are high,the Weitou Bay and the Zhao'an Bay are low,and in other bays are nearly the same.The pollution index of the inorganic arsenic ranges from 0.05 to 0.76 with an overall average of 0.23.And for the total arsenic,the pollution index is from 0.06~0.48 with an overall average of 0.21.They are all below the arsenics limit of natural food sanitation quality criteria in marine bivalve.The correlation between the total arsenic in the culture-shellfish and its length is overall positive.
2005, 27(6): 123-130.
Abstract:
Experiments about the effects of nitric oxide (NO) and iron on the growth of marine algae were conducted.The results of Skeletonema costatum are as fo llows:under the condition of iron limit,NO can promote the growth rate of marine microalga and increase the biomass obviously;but the influence of NO and iron on growth of phytoplankton is a complicated process,which is controlled by the NO concentration,the nutrition level of the culture medium and the iron concentration,etc;however,the iron concentration has a direct influence on the growth of algae and the release capacity of NO;therefore,the effects of NO and iron on the growth of marine phytoplankton are mutual.
Experiments about the effects of nitric oxide (NO) and iron on the growth of marine algae were conducted.The results of Skeletonema costatum are as fo llows:under the condition of iron limit,NO can promote the growth rate of marine microalga and increase the biomass obviously;but the influence of NO and iron on growth of phytoplankton is a complicated process,which is controlled by the NO concentration,the nutrition level of the culture medium and the iron concentration,etc;however,the iron concentration has a direct influence on the growth of algae and the release capacity of NO;therefore,the effects of NO and iron on the growth of marine phytoplankton are mutual.
2005, 27(6): 131-137.
Abstract:
The species composition and the temporal and spatial distribution of sand-dwelling dinoflagellates in the intertidal zone of the Huangcuo Beach,Xiamen Island,were investigated from August 2001 to July 2002.During the year-round survey,46 species of dinoflagellates had been identified,within which 39 species were recognized as benthic dinoflagellate,including 15 com mon species and four dominant species.Amphidinium britannicum and Adenoides sp.are two dominant species in the winter and spring,while Peridinium quinquecorne and Herdmanialittoralis are found dominant in summer and fall.Either the species number or cell density is high in spring and summer,but low in fall and winter,with a variation of about two orders of magnitudes in cell density.The cell density of dominant species and total cell density incline from the high-tide zone to middle-and low-tide zone.The main factors influencing on the distribution of benthic dinoflagellate in the east coastal beach of Xiamen Island,together with the possible link of benthic dinoflagellate with "colored sand" phenomena and near shore red tide,were discussed.
The species composition and the temporal and spatial distribution of sand-dwelling dinoflagellates in the intertidal zone of the Huangcuo Beach,Xiamen Island,were investigated from August 2001 to July 2002.During the year-round survey,46 species of dinoflagellates had been identified,within which 39 species were recognized as benthic dinoflagellate,including 15 com mon species and four dominant species.Amphidinium britannicum and Adenoides sp.are two dominant species in the winter and spring,while Peridinium quinquecorne and Herdmanialittoralis are found dominant in summer and fall.Either the species number or cell density is high in spring and summer,but low in fall and winter,with a variation of about two orders of magnitudes in cell density.The cell density of dominant species and total cell density incline from the high-tide zone to middle-and low-tide zone.The main factors influencing on the distribution of benthic dinoflagellate in the east coastal beach of Xiamen Island,together with the possible link of benthic dinoflagellate with "colored sand" phenomena and near shore red tide,were discussed.
2005, 27(6): 138-145.
Abstract:
Effects of urea,ammonium chloride,yeast extract and sodiumnitrate on growth and toxin production of Alexandrium minutum were studied.According to the results,A.minutum cultured with different nitrogen substrates showed quite different responses on growth and toxin production characteristics.Addition of sodium nitrate and yeast extract after nitrogen depletion can promote the growth of A.minutum.High concentration of ammonium chloride at the time of nutrient addition shows toxicity on A.minutum.However,the toxic effects disappear after 8 d and algae start to grow at a rate of 0.21 d-1,being similar to that with yeast extract and sodium nitrate.Urea has no obvious effect on the growth of A.minutum.However,urea can make the algae sustain at arelatively stable concentration compared with the rapid declination of the control group,where no nutrient is added.Addition of all the four nitrogen substrates after nitrogen depletion can promote to xin production in A.minutum.Similarly,the effect of urea is much weaker than the other three nutrients.Urea can make toxin content per cell sustain between 6.00 and 8.00 fmol.However,the tox in content per cell in algae with ammonium chloride,yeast extract and sodium nitrate as nitrogen sources can reach 11.85,12.86 and 14.64 fmol at the stable phage.All of the four nutrients have little effects on the toxin composition of A.minutum.In a word,bioavailability of sodium nitrate,ammonium chloride and yeast extract are similar to A.minutum,and that of urea is extremely low compared with the other three substrates.
Effects of urea,ammonium chloride,yeast extract and sodiumnitrate on growth and toxin production of Alexandrium minutum were studied.According to the results,A.minutum cultured with different nitrogen substrates showed quite different responses on growth and toxin production characteristics.Addition of sodium nitrate and yeast extract after nitrogen depletion can promote the growth of A.minutum.High concentration of ammonium chloride at the time of nutrient addition shows toxicity on A.minutum.However,the toxic effects disappear after 8 d and algae start to grow at a rate of 0.21 d-1,being similar to that with yeast extract and sodium nitrate.Urea has no obvious effect on the growth of A.minutum.However,urea can make the algae sustain at arelatively stable concentration compared with the rapid declination of the control group,where no nutrient is added.Addition of all the four nitrogen substrates after nitrogen depletion can promote to xin production in A.minutum.Similarly,the effect of urea is much weaker than the other three nutrients.Urea can make toxin content per cell sustain between 6.00 and 8.00 fmol.However,the tox in content per cell in algae with ammonium chloride,yeast extract and sodium nitrate as nitrogen sources can reach 11.85,12.86 and 14.64 fmol at the stable phage.All of the four nutrients have little effects on the toxin composition of A.minutum.In a word,bioavailability of sodium nitrate,ammonium chloride and yeast extract are similar to A.minutum,and that of urea is extremely low compared with the other three substrates.
2005, 27(6): 146-153.
Abstract:
To investigate the relation of sun-induced fluorescence peak near 700 nm to chlorophyll a concentration,data set of the reflectance spectra of red tide species such as Gymnodinium spp.,Heterosigma akashiwo,Ceratium furca and other algae such as Nitzschia closterium,Dicrateria zhanjiangensis Hu.Platymonas sp.,Chlorococcum sp.,Platymonas helgolandica var tsingtaoensis,Chlorella sp.getting from in situ and culture was measured.Because the magnitude and position of different algae's fluorescence peak vary with the increasing of chlorophyll a concentration.Reflectance at maximum red and 685 nm of spectrum was normalized to R560,max,R675,mini and R560,R675 separately.The results show that along with algae's variation,Rred,max/R560,max and Rred,max/R675,mini have better correlations with chlorophyll a concentration than R685/R560 and R685/R675,however,with the consideration of complex components of Case2 water and atmosphere correction error,Rred,max/R675,mini and R685/R675 are more suit able for retrieval of chlor ophylla concent ration in coastal water.Simultaneously three regression equations were put into use with all the regression coefficients more than 0.9 exept Heterosigma akashiwo.The R coefficient of regression equation of FLH=a+(Chla)b is better than the others with R more than 0.93,which shows that the relationship between fluo rescence characteristics of algae's water and chlorophyll a concentration is nonlinear.
To investigate the relation of sun-induced fluorescence peak near 700 nm to chlorophyll a concentration,data set of the reflectance spectra of red tide species such as Gymnodinium spp.,Heterosigma akashiwo,Ceratium furca and other algae such as Nitzschia closterium,Dicrateria zhanjiangensis Hu.Platymonas sp.,Chlorococcum sp.,Platymonas helgolandica var tsingtaoensis,Chlorella sp.getting from in situ and culture was measured.Because the magnitude and position of different algae's fluorescence peak vary with the increasing of chlorophyll a concentration.Reflectance at maximum red and 685 nm of spectrum was normalized to R560,max,R675,mini and R560,R675 separately.The results show that along with algae's variation,Rred,max/R560,max and Rred,max/R675,mini have better correlations with chlorophyll a concentration than R685/R560 and R685/R675,however,with the consideration of complex components of Case2 water and atmosphere correction error,Rred,max/R675,mini and R685/R675 are more suit able for retrieval of chlor ophylla concent ration in coastal water.Simultaneously three regression equations were put into use with all the regression coefficients more than 0.9 exept Heterosigma akashiwo.The R coefficient of regression equation of FLH=a+(Chla)b is better than the others with R more than 0.93,which shows that the relationship between fluo rescence characteristics of algae's water and chlorophyll a concentration is nonlinear.
2005, 27(6): 154-161.
Abstract:
Conditions required for the induction of gynogenetic diploid by suppression of first cleavage of Chlamys farreri were examined using treatments of cytochalasin B (0.5 g/cm3;CB) and 6-dimethylamin-opurine (60 g/cm3;6-DMAP).Treatments with CB and 6-DMAP were effective in inhibiting not only meiosis but alsomitosis,and the optimum time for the suppression of first cleavage began at 60~65 min with 20 and 15 min duration time after insemination.This resulted in 12.5% and 27.5% mitotic gynogenetic diploids (mitotic-G2N) respectively.Cytological observations indicated that 6-DMAP disrupted the spindle at mitosis and inhibited chromosome movement,resulting in the formation of one diploid female nucleus,while CB inhibited the cytokinesis of first cleavage but not the segregation of chromosomes.Although attempts to produce mitotic-G2N demonstrated that ploidy levels and the developmental rate of D-shaped lar-vaearelow,the results of this study suggest the possibility of producing mitotic-G2N Chalamys farreri.
Conditions required for the induction of gynogenetic diploid by suppression of first cleavage of Chlamys farreri were examined using treatments of cytochalasin B (0.5 g/cm3;CB) and 6-dimethylamin-opurine (60 g/cm3;6-DMAP).Treatments with CB and 6-DMAP were effective in inhibiting not only meiosis but alsomitosis,and the optimum time for the suppression of first cleavage began at 60~65 min with 20 and 15 min duration time after insemination.This resulted in 12.5% and 27.5% mitotic gynogenetic diploids (mitotic-G2N) respectively.Cytological observations indicated that 6-DMAP disrupted the spindle at mitosis and inhibited chromosome movement,resulting in the formation of one diploid female nucleus,while CB inhibited the cytokinesis of first cleavage but not the segregation of chromosomes.Although attempts to produce mitotic-G2N demonstrated that ploidy levels and the developmental rate of D-shaped lar-vaearelow,the results of this study suggest the possibility of producing mitotic-G2N Chalamys farreri.
2005, 27(6): 162-169.
Abstract:
On the basis of the analysis for data collected in field measurements,the model of combined wave and tidal current was used to simulate the residual current movements and sediment transport in the Houjiang nearshore area of East Guangdong,China.The results show that the northeastly wind is the dominant forcing to southwestly residual circulation currents,while waves control the resuspension of sediments and bedload transport processes.And the nearshore topography evolution is characterizeed by the trends of erosion for the northern area and deposition for the southern area.
On the basis of the analysis for data collected in field measurements,the model of combined wave and tidal current was used to simulate the residual current movements and sediment transport in the Houjiang nearshore area of East Guangdong,China.The results show that the northeastly wind is the dominant forcing to southwestly residual circulation currents,while waves control the resuspension of sediments and bedload transport processes.And the nearshore topography evolution is characterizeed by the trends of erosion for the northern area and deposition for the southern area.
2005, 27(6): 170-176.
Abstract:
2005, 27(6): 177-179.
Abstract:
2005, 27(6): 180-186.
Abstract:
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