2007 Vol. 29, No. 2
Display Method:
2007, 29(2): 1-17.
Abstract:
Overview of studies on some cyclonic and anticyclonic eddies is made in the East China Sea and the region east of the Ryukyu Islands.In the continental shelf above 200 m level in the East China Sea (ECS),we discuss mainly an antti-cy clonic eddy in southwestern part of the ECS,a cyclonic mesoscale eddy southwest of Cheju Island and a cyclonic eddy northeast of Changjiang.In the region near continental slope and both sides of the Kuroshio in the ECS,there are some mesoscale eddies with the different scales,and one of their dynamical causes maybe due to the Kuroshio meander in the ECS.The second dynamical causes are related to the topographic relief and existence of Ryukyu Islands.There are two types of the meanders of the Kuroshio in the ECS:the Kuroshio front meander and the Kuroshio path meander.For the Kuroshio front meander,their time and space scales and the structure of the Kuroshio frontal eddy are reviewed.For the Kuroshio path meander,we discuss the mesoscalecy clonic and anticy clonic eddies on both sides of the Kuroshio and the variability of their character.Especially,we discuss with emphasis the interaction between the Kuroshio path meander and the mesoscale eddy,and point out that the following fact.When the growing cyclonic eddy in the northern Okinawa Trough dominates variability at periods of 1~3 months and its scale grows to about 200 km corresponding to the zonal scale grows to about Okinaw a Trough,the Kuroshio path translates from the northern path to southern one.We also review the interaction between the volume transport of the Kuroshio in the ECS and the mesoscale eddy.In the regions east and south of the Ryukyu Islands,there are some mesoscale cyclonic and anticyclonic eddies with different scales,and the variability of their character is also reviewed.
Overview of studies on some cyclonic and anticyclonic eddies is made in the East China Sea and the region east of the Ryukyu Islands.In the continental shelf above 200 m level in the East China Sea (ECS),we discuss mainly an antti-cy clonic eddy in southwestern part of the ECS,a cyclonic mesoscale eddy southwest of Cheju Island and a cyclonic eddy northeast of Changjiang.In the region near continental slope and both sides of the Kuroshio in the ECS,there are some mesoscale eddies with the different scales,and one of their dynamical causes maybe due to the Kuroshio meander in the ECS.The second dynamical causes are related to the topographic relief and existence of Ryukyu Islands.There are two types of the meanders of the Kuroshio in the ECS:the Kuroshio front meander and the Kuroshio path meander.For the Kuroshio front meander,their time and space scales and the structure of the Kuroshio frontal eddy are reviewed.For the Kuroshio path meander,we discuss the mesoscalecy clonic and anticy clonic eddies on both sides of the Kuroshio and the variability of their character.Especially,we discuss with emphasis the interaction between the Kuroshio path meander and the mesoscale eddy,and point out that the following fact.When the growing cyclonic eddy in the northern Okinawa Trough dominates variability at periods of 1~3 months and its scale grows to about 200 km corresponding to the zonal scale grows to about Okinaw a Trough,the Kuroshio path translates from the northern path to southern one.We also review the interaction between the volume transport of the Kuroshio in the ECS and the mesoscale eddy.In the regions east and south of the Ryukyu Islands,there are some mesoscale cyclonic and anticyclonic eddies with different scales,and the variability of their character is also reviewed.
2007, 29(2): 18-24.
Abstract:
Temperature and salinity measured by profile floats,upper layer temperature and ECCO wind stress field were used to study the seasonal variations of the front paths and wind stress field in the Southeast.Indian Ocean and analyze the fronto genesis of Subtropical Front(STF) and Subantarctic Front(SAF) preliminarily.We found that the seasonally averaged Agulhas Front(AF) can extend to 80 E and 82 E in summer and winter,respectively In most cases AF,SAF and South Subtropical Front(SSTF) converge and pass through Kerguelen-Amsterdam Passage as one front.The paths of SAF and PF are more southward in winter than those in summer in the downst reamdeep basin of Kerguelen Plateau Positive and negative wind stresscurl core appearalt ernately from north to south right downst ream of Kerguelen Plateau.The zero wind stresscurl is more northward in winter than in summer between 85 E and 105 ESTF locates at the area within the convergence Ekman pumping in this area results in the convergence of surface water,which could cause the formation of STF and help to maintain it.The seasonal shift of SAF is less than that of zero wind stresscurl,which causes that SAF locates at the area with weak positive wind stresscurl in summer while at the area with negative wind stresscurl in winter and means that wind stresscurl is not the directly external cause of the SAF fronto genesis.
Temperature and salinity measured by profile floats,upper layer temperature and ECCO wind stress field were used to study the seasonal variations of the front paths and wind stress field in the Southeast.Indian Ocean and analyze the fronto genesis of Subtropical Front(STF) and Subantarctic Front(SAF) preliminarily.We found that the seasonally averaged Agulhas Front(AF) can extend to 80 E and 82 E in summer and winter,respectively In most cases AF,SAF and South Subtropical Front(SSTF) converge and pass through Kerguelen-Amsterdam Passage as one front.The paths of SAF and PF are more southward in winter than those in summer in the downst reamdeep basin of Kerguelen Plateau Positive and negative wind stresscurl core appearalt ernately from north to south right downst ream of Kerguelen Plateau.The zero wind stresscurl is more northward in winter than in summer between 85 E and 105 ESTF locates at the area within the convergence Ekman pumping in this area results in the convergence of surface water,which could cause the formation of STF and help to maintain it.The seasonal shift of SAF is less than that of zero wind stresscurl,which causes that SAF locates at the area with weak positive wind stresscurl in summer while at the area with negative wind stresscurl in winter and means that wind stresscurl is not the directly external cause of the SAF fronto genesis.
2007, 29(2): 25-33.
Abstract:
The Arctic climate is experiencing obvious change,and the variations in the area and thickness of seaice are the uppermost charact eristics.The ice cover in the Chukchi Sea represents mostly the variation of Arcitc seaice cover.In this paper,the variations of ice area within nine years in the Chukchi Sea are studied by using the remote sensing seaice data.The results show that the annual difference of sea ice area is not able in different year.During the years of 1997~2005,the ice area underwent a course from lightice year(1997) to heavy ice year(2000~2001) and then reg ressed light ice years(2002~2005).As a whole,the ice area presents a decr easing trend,and the ice condition was the lightest in the year 2005.The duration of ice melting correlated well with the ice condition.In the lightice year,the melting begins earlier and freezes-up later.The minimum sea ice cover appear in the late Septem ber to early October each year,whose areas are quite different,4% in the light ice years and more than 50% in the heavyice years.Some major indices,Sea Ice Area Index,Minimum Sea Ice Area,Accumulated Temperature Anomaly and two Wind Driven Indices are chosen to express the multi-year variations of the sea ice cover and the impact from local climate.The Accumulated Temperature during winter has obvious impact on the ice condition of the coming year.Local wind field is a key fact to change the ice cover in short time by causing the compression or extension of low concentr ationice in summertime.
The Arctic climate is experiencing obvious change,and the variations in the area and thickness of seaice are the uppermost charact eristics.The ice cover in the Chukchi Sea represents mostly the variation of Arcitc seaice cover.In this paper,the variations of ice area within nine years in the Chukchi Sea are studied by using the remote sensing seaice data.The results show that the annual difference of sea ice area is not able in different year.During the years of 1997~2005,the ice area underwent a course from lightice year(1997) to heavy ice year(2000~2001) and then reg ressed light ice years(2002~2005).As a whole,the ice area presents a decr easing trend,and the ice condition was the lightest in the year 2005.The duration of ice melting correlated well with the ice condition.In the lightice year,the melting begins earlier and freezes-up later.The minimum sea ice cover appear in the late Septem ber to early October each year,whose areas are quite different,4% in the light ice years and more than 50% in the heavyice years.Some major indices,Sea Ice Area Index,Minimum Sea Ice Area,Accumulated Temperature Anomaly and two Wind Driven Indices are chosen to express the multi-year variations of the sea ice cover and the impact from local climate.The Accumulated Temperature during winter has obvious impact on the ice condition of the coming year.Local wind field is a key fact to change the ice cover in short time by causing the compression or extension of low concentr ationice in summertime.
2007, 29(2): 34-44.
Abstract:
Using the CCM3/NCAR,a series of numerical experiments are designed to explore the oceanland interlaced distribution of Africa-Arabian Sea(AS)-India Peninsula-Bay of Bengal(BOB) -Indochina Peninsula-South China Sea(SCS) on the form ation of the Asian Winter Monsoon circulation.The results show that:(1) the oceanOland thermal difference over southern Asia is the primary mechanism that maintains the AS,BOB and SCS winter monsoon circulation and the associated cross-equatorial currents,and its deter minant effect on the formation of the tropical winter north wind component is also revealed;the subplanetary scale thermal contrast likewise exerts pronounced effects on the formation of subtropical and highOlat itudes monsoon;(2) the presence of Indo china Peninsula is liable for a southw ard shift of the continental winter monsoon at SCS during its west ward propagation as to form SCS winterm onsoon,indicating that Indochina Peninsula not only af fects the neighbo ring local winter monsoon,but has an important influence on its propagation.Moreover,because of its more adjacent to the source region of winter monsoon than India and Africa,the elimination of Indochina Peninsula would result in greater variations of winter monsoon in the lower reaches;(3) the presence of Africa,Indian subcont inent and Indochina Peninsula also actsas a crucial role in the formation of the upperair subtropical jets.In addition,the impacts of these thermal contrasts on the distribution of the winter precipitation and surface temperature are also investigated.
Using the CCM3/NCAR,a series of numerical experiments are designed to explore the oceanland interlaced distribution of Africa-Arabian Sea(AS)-India Peninsula-Bay of Bengal(BOB) -Indochina Peninsula-South China Sea(SCS) on the form ation of the Asian Winter Monsoon circulation.The results show that:(1) the oceanOland thermal difference over southern Asia is the primary mechanism that maintains the AS,BOB and SCS winter monsoon circulation and the associated cross-equatorial currents,and its deter minant effect on the formation of the tropical winter north wind component is also revealed;the subplanetary scale thermal contrast likewise exerts pronounced effects on the formation of subtropical and highOlat itudes monsoon;(2) the presence of Indo china Peninsula is liable for a southw ard shift of the continental winter monsoon at SCS during its west ward propagation as to form SCS winterm onsoon,indicating that Indochina Peninsula not only af fects the neighbo ring local winter monsoon,but has an important influence on its propagation.Moreover,because of its more adjacent to the source region of winter monsoon than India and Africa,the elimination of Indochina Peninsula would result in greater variations of winter monsoon in the lower reaches;(3) the presence of Africa,Indian subcont inent and Indochina Peninsula also actsas a crucial role in the formation of the upperair subtropical jets.In addition,the impacts of these thermal contrasts on the distribution of the winter precipitation and surface temperature are also investigated.
2007, 29(2): 45-50.
Abstract:
On the basis of the requirement of fully using remote sensing capabilities in monitoring ocean,some sea tests have been made to measure the physical and optical properties of ship wakes which contain bubbles,and to investigate how bubble populations affect the optical properties of different water bodies,such as water leaving radiance and remote sensing reflectance.These studies can provide some theoretics for capturing the information of ship wakes by the remote sensing from spectral sensors carried by satellite.These test sproved that the water leaving radiance and remote sensing reflectance of ship wakes which contain bubbles are more or less higher than the backg round waters over the visible and infrared wave bands,and whether relatively amplitude value or absolute am plitude value of the spectral backscattering of wakes with bubbles in Case I water bodies is farmore than in Case Ⅱ water bodies.
On the basis of the requirement of fully using remote sensing capabilities in monitoring ocean,some sea tests have been made to measure the physical and optical properties of ship wakes which contain bubbles,and to investigate how bubble populations affect the optical properties of different water bodies,such as water leaving radiance and remote sensing reflectance.These studies can provide some theoretics for capturing the information of ship wakes by the remote sensing from spectral sensors carried by satellite.These test sproved that the water leaving radiance and remote sensing reflectance of ship wakes which contain bubbles are more or less higher than the backg round waters over the visible and infrared wave bands,and whether relatively amplitude value or absolute am plitude value of the spectral backscattering of wakes with bubbles in Case I water bodies is farmore than in Case Ⅱ water bodies.
2007, 29(2): 51-58.
Abstract:
28 organism and 14 surface sediment samples from Daya Bay were collected to determine the compositions and concentrations of dichlorodiphenyltrichloroethanes(DDTs),hexachloro cyclohexanes (HCHs) and chlordanes(CHLs) in 2003.Stable isotope δ15N,δ13C values and lipid contents in organism were also measured.Attention was paid to study the OCPs pollution status in sediment and organisms and their bioaccum ulation law in Day a Bay.Average concentrations of DDTs,HCHs and CHLs in fishes were 57.1 52.9,0.30 0.18 and 0.87 0.35 ng/g wet weight,respectively.DDTs levels in organisms from Daya Bay were relatively higher and HCHs and CHLs levels were lower compared with those in other waters.High percent of p,p-DDT levels in surface sediments and relatively low(DDE+DDD) /DDT ratios (mean 0.56,<1) indicated new DDTs sources input to the bay.OCPs bioaccumulation was found to have a liposoluble charact eristics,the higher lipid content in organism the more OCPs accumulating in organism.Research on δ15N and δ13C in organisms showed that carnivorous fishes are liable to accumulate OCPs than planktivorous fishes.Significant correlation was observed between Biota-Sediment Accumulation Factors(BSAF) of OCPs and their lipophilic property,i.e.ratios of octanol/water(KOW),in the waters of Daya Bay.
28 organism and 14 surface sediment samples from Daya Bay were collected to determine the compositions and concentrations of dichlorodiphenyltrichloroethanes(DDTs),hexachloro cyclohexanes (HCHs) and chlordanes(CHLs) in 2003.Stable isotope δ15N,δ13C values and lipid contents in organism were also measured.Attention was paid to study the OCPs pollution status in sediment and organisms and their bioaccum ulation law in Day a Bay.Average concentrations of DDTs,HCHs and CHLs in fishes were 57.1 52.9,0.30 0.18 and 0.87 0.35 ng/g wet weight,respectively.DDTs levels in organisms from Daya Bay were relatively higher and HCHs and CHLs levels were lower compared with those in other waters.High percent of p,p-DDT levels in surface sediments and relatively low(DDE+DDD) /DDT ratios (mean 0.56,<1) indicated new DDTs sources input to the bay.OCPs bioaccumulation was found to have a liposoluble charact eristics,the higher lipid content in organism the more OCPs accumulating in organism.Research on δ15N and δ13C in organisms showed that carnivorous fishes are liable to accumulate OCPs than planktivorous fishes.Significant correlation was observed between Biota-Sediment Accumulation Factors(BSAF) of OCPs and their lipophilic property,i.e.ratios of octanol/water(KOW),in the waters of Daya Bay.
2007, 29(2): 59-66.
Abstract:
Fractal geometry is a good method to describe the natural nonlinear phenomena quantitatively,and fractal dimension is a quant it ative parameter.The fractal geometry is applied to studying the fault systems in the southern part of the South China Sea.Results indicate that the spatial distribution of all faults in the southern part of the South China Sea is a distinct fractal set with selfOsimilarity in the nonOscale range of 25~250 km,and the fractal dimension(capacity dimensions),obtained by a box-counting method,interprets well the characteristics of the spatial distribution of faults.The fractal dimension of all faults in the study area is 1.6601,that of the NEOt rending faults 1.3875 and that of the NWOt rending faults 1.269 3.Showed by isoline maps of fractal dimensions,faults arrange symmetrically on two sides along the spreading axis of the Southwest Subbasin;the densities of spatial distribution of the NEOt rending faults and the N WOt rending faults supplement to each other,indicating the interOrest raint properties of these two groups of faults.At last,correlating the fractal charact eristics of the spatial distribution of faults with the evolution of the South China Sea and the distribution of basins bearing oil or gas,it is tried to find out the relationship between the fractal characteristics and evolution of the South China Sea and that between the fractal charact eristics and distribution of basins bearing oil or gas.
Fractal geometry is a good method to describe the natural nonlinear phenomena quantitatively,and fractal dimension is a quant it ative parameter.The fractal geometry is applied to studying the fault systems in the southern part of the South China Sea.Results indicate that the spatial distribution of all faults in the southern part of the South China Sea is a distinct fractal set with selfOsimilarity in the nonOscale range of 25~250 km,and the fractal dimension(capacity dimensions),obtained by a box-counting method,interprets well the characteristics of the spatial distribution of faults.The fractal dimension of all faults in the study area is 1.6601,that of the NEOt rending faults 1.3875 and that of the NWOt rending faults 1.269 3.Showed by isoline maps of fractal dimensions,faults arrange symmetrically on two sides along the spreading axis of the Southwest Subbasin;the densities of spatial distribution of the NEOt rending faults and the N WOt rending faults supplement to each other,indicating the interOrest raint properties of these two groups of faults.At last,correlating the fractal charact eristics of the spatial distribution of faults with the evolution of the South China Sea and the distribution of basins bearing oil or gas,it is tried to find out the relationship between the fractal characteristics and evolution of the South China Sea and that between the fractal charact eristics and distribution of basins bearing oil or gas.
2007, 29(2): 67-73.
Abstract:
Problems about acquirement of basic data which are utilized to assess the present cobal-trich crust resource in our country are analyzed and discussed using an arithmetic average method,a corresponding ameliorative scheme is given,new parameters,e.g.,arisen frequency of mine and ore-forming coefficient are brought forward and introduced,and the shortages of present method are am eliorated.Furthermore encircling the border line item of presentore delineation needed to be solved urgently,the relevant theory in an invest igaton method,data processing and borderline ascert ainment is discussed.This work will offer technical support to our countryps present cobal-trich crust application or earea selection,oredelineation and resource assessment,also be the important gist to or earea reinforcing and crustreserves counting latterly.
Problems about acquirement of basic data which are utilized to assess the present cobal-trich crust resource in our country are analyzed and discussed using an arithmetic average method,a corresponding ameliorative scheme is given,new parameters,e.g.,arisen frequency of mine and ore-forming coefficient are brought forward and introduced,and the shortages of present method are am eliorated.Furthermore encircling the border line item of presentore delineation needed to be solved urgently,the relevant theory in an invest igaton method,data processing and borderline ascert ainment is discussed.This work will offer technical support to our countryps present cobal-trich crust application or earea selection,oredelineation and resource assessment,also be the important gist to or earea reinforcing and crustreserves counting latterly.
2007, 29(2): 74-81.
Abstract:
Data of water depth,temperature,salinity and suspended particles samples at 12 stations in the Pacific Ocean were collected in 2005.According to the vertical distribution of suspended particles concentration,the distributing characteristics of marine nepheloid layers are primarily analyzed and compared in different marine conditions,and origins of these particulate matter are discussed.The concentration of suspended particles in an ocean water volume is very low,generally less than 0.3 mg/dm3.While in some layers the concent ration of suspended particles is relatively high,then the nepheloid layers are formed.In the oceans,they generally occur as surface and near-bot to mnepheloid layers everywhere.The formation of surface nepheloid layers is mostly influenced by euphotic biology,while the resuspension of bottom sediments plays an important role on the formation of near-bottom nepheloid layers.At the top of seamounts,there are no nepheloid layers because of for mation influence of water current and rock base,while the nepheloid layers occur more frequently at the bottom and the China Pioneer Area.In the western China Pioneer Area near volcanicorifices,the concent ration of suspended particles is higher than that in the eastern.
Data of water depth,temperature,salinity and suspended particles samples at 12 stations in the Pacific Ocean were collected in 2005.According to the vertical distribution of suspended particles concentration,the distributing characteristics of marine nepheloid layers are primarily analyzed and compared in different marine conditions,and origins of these particulate matter are discussed.The concentration of suspended particles in an ocean water volume is very low,generally less than 0.3 mg/dm3.While in some layers the concent ration of suspended particles is relatively high,then the nepheloid layers are formed.In the oceans,they generally occur as surface and near-bot to mnepheloid layers everywhere.The formation of surface nepheloid layers is mostly influenced by euphotic biology,while the resuspension of bottom sediments plays an important role on the formation of near-bottom nepheloid layers.At the top of seamounts,there are no nepheloid layers because of for mation influence of water current and rock base,while the nepheloid layers occur more frequently at the bottom and the China Pioneer Area.In the western China Pioneer Area near volcanicorifices,the concent ration of suspended particles is higher than that in the eastern.
2007, 29(2): 82-91.
Abstract:
The collaborative preparation of three seamount cobalt-rich crust reference materials GSM C-1~3 by China and Russia is presented.The samples were sampled from the western and central Pacific seamount zones.After the raw samples were dried in ambient air and crushed,they were ground in a ball mill to form a well-mixed powder.The homogeneity of the samples wastested using X-ray fluo rescence spectrometry(XRF) with high-precision.Eight home laboratories and eight international laboratories participated in the collaborative analysis programme.Fifty-seven elements or constituents were analy sed,and among those,43 were certified in GSM C-1 and 2,and 45 const it uents were certified in GSMC-3.Ten constituents were regarded as information value in GSM C-1 and 2,and eight const ituents were regarded as information value in GSM C-3.These three reference materials have been approved as certified reference materials by the Administ ration of Quality Supervision and Inspection and Quarantine(AQSIQ,China) in 2005,the serial number is GBW07337 for GSM C-1,GBW07338 for GSM C-2 and GBW07339 for GSM C-3.
The collaborative preparation of three seamount cobalt-rich crust reference materials GSM C-1~3 by China and Russia is presented.The samples were sampled from the western and central Pacific seamount zones.After the raw samples were dried in ambient air and crushed,they were ground in a ball mill to form a well-mixed powder.The homogeneity of the samples wastested using X-ray fluo rescence spectrometry(XRF) with high-precision.Eight home laboratories and eight international laboratories participated in the collaborative analysis programme.Fifty-seven elements or constituents were analy sed,and among those,43 were certified in GSM C-1 and 2,and 45 const it uents were certified in GSMC-3.Ten constituents were regarded as information value in GSM C-1 and 2,and eight const ituents were regarded as information value in GSM C-3.These three reference materials have been approved as certified reference materials by the Administ ration of Quality Supervision and Inspection and Quarantine(AQSIQ,China) in 2005,the serial number is GBW07337 for GSM C-1,GBW07338 for GSM C-2 and GBW07339 for GSM C-3.
2007, 29(2): 92-97.
Abstract:
Sampling technology of deep sea sediment is very important for many aspects of ocean researches because the realization amony their research goals is closely related to the quality of sediment samples.While the soft or lightly clotty sediment is sampled with general pipecores,it is always inevitable that sediment samples are disturbed.On the basis of an original equipment witch is named as the manipulat or holding sedimentcorer,a model of sampling process is built and the theory of sampling disturbing is analyzed;the extrusion expansion solution of sediment is gotten through adopting the spherical cavity expansion theory;finally,combining with actual parameters of the Pacific Ocean sediment,a quantitative description on disturbing status of deep sea sediment is presented,and a conclusion that the wall thickness of the core is a key parameter for reducing disturbing is put forward.
Sampling technology of deep sea sediment is very important for many aspects of ocean researches because the realization amony their research goals is closely related to the quality of sediment samples.While the soft or lightly clotty sediment is sampled with general pipecores,it is always inevitable that sediment samples are disturbed.On the basis of an original equipment witch is named as the manipulat or holding sedimentcorer,a model of sampling process is built and the theory of sampling disturbing is analyzed;the extrusion expansion solution of sediment is gotten through adopting the spherical cavity expansion theory;finally,combining with actual parameters of the Pacific Ocean sediment,a quantitative description on disturbing status of deep sea sediment is presented,and a conclusion that the wall thickness of the core is a key parameter for reducing disturbing is put forward.
2007, 29(2): 98-104.
Abstract:
Stable isotope techniques are commonly used to represent the trophic structure of aquatic systems.Based on the bottom trawl surveys in the central and southern part of the Huanghai Sea and adjacent sea area of Changjing River Estuary during the spawning season of Spring in 2005,we mainly focus on the stable carbon(13C/12C) and nitrogen isotope(15N/14N) ratios of anchovy and its potential food,such as zooplankt on,Euphausia pacifica,larvae and juvenile fish,Leptochela gracilis,Loligo beka in order to acknow ledge the feeding habit of anchovy.Application of 13C and 15N in dietary study depends upon the differentiation in the isotopic composition of various food sources.The 13C and 15N values of anchovy and its potential food indicated that its food sources in these areas were composed of zooplankt on,Euphausia pacifica,fish larvae and juvenile fish.Especially,500~900 m zooplankt on was the most important dietary component for anchovy,accounting for 61%~84% of the total food by weight,the food proportion of the fish larvae and juvenile fish was 16%~21%,which was less than the results with the method of stomach content analysis;the variations in δ13C and δ15N values of anchovy in the central of the Huanghai Sea were higher than the area of southern part of the Huanghai Sea and adjacent sea of Changjing River Estuary,the reason were likely to difference between the sources of Anchovy energy or the length of the food chain in the different areas of the central and southern of Huanghai Sea and adjacent sea area of Changjiang River Estuary.Stableiso to peanalysis(δ13C and δ15N) can be a powerful tool in both identifying the source of organic matter that supports fish production and investigating food web remains untested using traditional dietary methods in the modern ecology.
Stable isotope techniques are commonly used to represent the trophic structure of aquatic systems.Based on the bottom trawl surveys in the central and southern part of the Huanghai Sea and adjacent sea area of Changjing River Estuary during the spawning season of Spring in 2005,we mainly focus on the stable carbon(13C/12C) and nitrogen isotope(15N/14N) ratios of anchovy and its potential food,such as zooplankt on,Euphausia pacifica,larvae and juvenile fish,Leptochela gracilis,Loligo beka in order to acknow ledge the feeding habit of anchovy.Application of 13C and 15N in dietary study depends upon the differentiation in the isotopic composition of various food sources.The 13C and 15N values of anchovy and its potential food indicated that its food sources in these areas were composed of zooplankt on,Euphausia pacifica,fish larvae and juvenile fish.Especially,500~900 m zooplankt on was the most important dietary component for anchovy,accounting for 61%~84% of the total food by weight,the food proportion of the fish larvae and juvenile fish was 16%~21%,which was less than the results with the method of stomach content analysis;the variations in δ13C and δ15N values of anchovy in the central of the Huanghai Sea were higher than the area of southern part of the Huanghai Sea and adjacent sea of Changjing River Estuary,the reason were likely to difference between the sources of Anchovy energy or the length of the food chain in the different areas of the central and southern of Huanghai Sea and adjacent sea area of Changjiang River Estuary.Stableiso to peanalysis(δ13C and δ15N) can be a powerful tool in both identifying the source of organic matter that supports fish production and investigating food web remains untested using traditional dietary methods in the modern ecology.
2007, 29(2): 105-111.
Abstract:
105 species of Mollusca were obtained from the intertidal zone in Nanji Archipalego Marine Nature Reserve during A pril and August of 2003,of which 93 species in rocky shore,12 species in sandy shore,and 6 species are newly recorded in this area.The average biomass and density are 3025.70 g/m2,2660 ind/m2 and 29.43 g/m2,11 ind/m2 in rocky shore and Sandy shore.Diversity index is 1.25~2.20,while evenness index is 0.54~0.70 in rocky shore.And diversity index is 0.23~0.95,while evenness index is 0.17~0.94 in Sandy shore.Compared to historical data,seashell amount declined dramaticly in Sandy shore,but increased reasonable in rocky shore.
105 species of Mollusca were obtained from the intertidal zone in Nanji Archipalego Marine Nature Reserve during A pril and August of 2003,of which 93 species in rocky shore,12 species in sandy shore,and 6 species are newly recorded in this area.The average biomass and density are 3025.70 g/m2,2660 ind/m2 and 29.43 g/m2,11 ind/m2 in rocky shore and Sandy shore.Diversity index is 1.25~2.20,while evenness index is 0.54~0.70 in rocky shore.And diversity index is 0.23~0.95,while evenness index is 0.17~0.94 in Sandy shore.Compared to historical data,seashell amount declined dramaticly in Sandy shore,but increased reasonable in rocky shore.
2007, 29(2): 112-122.
Abstract:
Abundance,biomass and production of bact erioplankt on,primary production,new production,and the related environmental parameters were measured in the Zhujiang River Estuary and the adjacent northern South China Sea in winter and summer of 2004.The results showed that the substrate supply,including dissolved organic mater from phytoplankt on and river input and inorg anic nutrients,mightbe the most important factor governing the spatial patterns of the standing stock and production of bact erioplankton.As the results,biomass and production of bact erioplankt on gradually decreased from the estuary to the shelf and open sea along the salinity gradient.IBP:IPP ratios,r anged 4%~96%,were negatively correlated with IPP,while the spatial patterns of IBP:IPP ratios were opposite to that of new produc-tion f-ratio.Furthermore,the spatial difference of the importance of bacterio plankt on in the euphotic zone material cycle was also discussed.
Abundance,biomass and production of bact erioplankt on,primary production,new production,and the related environmental parameters were measured in the Zhujiang River Estuary and the adjacent northern South China Sea in winter and summer of 2004.The results showed that the substrate supply,including dissolved organic mater from phytoplankt on and river input and inorg anic nutrients,mightbe the most important factor governing the spatial patterns of the standing stock and production of bact erioplankton.As the results,biomass and production of bact erioplankt on gradually decreased from the estuary to the shelf and open sea along the salinity gradient.IBP:IPP ratios,r anged 4%~96%,were negatively correlated with IPP,while the spatial patterns of IBP:IPP ratios were opposite to that of new produc-tion f-ratio.Furthermore,the spatial difference of the importance of bacterio plankt on in the euphotic zone material cycle was also discussed.
2007, 29(2): 123-130.
Abstract:
The sensitivities of a toxic strain of Alexandrium tamarense(Lebour) Balech to eig ht antibiotics:chloram phenicol(Cm),erythromy cin(Er),lincomy cin(Lm),gentamicin(Gm),auromycin(Aum),ampicillin(Amp),neomycin(Nm) and strepto mycin(Str) were reported in the present studies.The result revealed that this dinoflag ellate was sensitive to five of the eight antibiotics.The EC50(50% effective concent ration) of specific growth rate after 8 days were 2.45 Lg/cm3,25.2 Lg/cm3,7.95 Lg/cm3,285 u/cm3 and 58.7 Lg/cm3 for Cm,Er,L m,Gm and Aum respectively.The five antibiotics were applicable as selective reagents,and the correspondent genes maybe employed as positive selective markersing enetic engineering of Alexandrium tamarense.On the contrary,Nm and Strhad noinhibition effects on the growth of the algae.These two antibiotics could be used in sterile purification of A.tamarense for clarifying the mechanism of the toxigenicity and the out break of the red tide.The inhibition effect of the selected antiobiotics were further tested.
The sensitivities of a toxic strain of Alexandrium tamarense(Lebour) Balech to eig ht antibiotics:chloram phenicol(Cm),erythromy cin(Er),lincomy cin(Lm),gentamicin(Gm),auromycin(Aum),ampicillin(Amp),neomycin(Nm) and strepto mycin(Str) were reported in the present studies.The result revealed that this dinoflag ellate was sensitive to five of the eight antibiotics.The EC50(50% effective concent ration) of specific growth rate after 8 days were 2.45 Lg/cm3,25.2 Lg/cm3,7.95 Lg/cm3,285 u/cm3 and 58.7 Lg/cm3 for Cm,Er,L m,Gm and Aum respectively.The five antibiotics were applicable as selective reagents,and the correspondent genes maybe employed as positive selective markersing enetic engineering of Alexandrium tamarense.On the contrary,Nm and Strhad noinhibition effects on the growth of the algae.These two antibiotics could be used in sterile purification of A.tamarense for clarifying the mechanism of the toxigenicity and the out break of the red tide.The inhibition effect of the selected antiobiotics were further tested.
2007, 29(2): 131-136.
Abstract:
The manual cultured Porphyra haitanensis thallus and five large scale unwanted-alga which have growth competitive relations with P.haitanensis thallus:Enteromorphaintestinalis,E.clathrata,Ulva pertusa,Gracilaria asiatica and Ectocarp us confervoides,together with the samples of Cocconeis spp.,were tested by means of desiccation and cold preservation.The results indicated that when it was cultured directly after being desiccated to the water content of 10%~15%,the survival rate of the P.haitanensis thallus was over 99%,showing no significant difference from those without desiccation,where as all the large scale unwanted-alga would die if the water content was below 25% after desiccation.When the water content of the P.haitanensis thallus was 10%,culture them after being stored at a low temperature of 20 for 30 days,then the survival rate would reach up to 99%~100%.If the water ratio was below 10%,then the survival rate would belower than 30%,and death even occurred.When the P.haitanensis thallus was stored with the water content ratio higher or lower than 10%~15% under low temperature,both its survival rate and the rate of weight gain when cultured after cold preservation would get aff ected.However,cold preser vation duration would bring a 100% death rate to the large scale unwanted-alga.Therefore,the ways of desiccation and cold preservation could effectively kill the unwanted-algas that have competitive relations with P.haitanensis thallus,which could be applied to raising the yield of P.haitanensis in practice.
The manual cultured Porphyra haitanensis thallus and five large scale unwanted-alga which have growth competitive relations with P.haitanensis thallus:Enteromorphaintestinalis,E.clathrata,Ulva pertusa,Gracilaria asiatica and Ectocarp us confervoides,together with the samples of Cocconeis spp.,were tested by means of desiccation and cold preservation.The results indicated that when it was cultured directly after being desiccated to the water content of 10%~15%,the survival rate of the P.haitanensis thallus was over 99%,showing no significant difference from those without desiccation,where as all the large scale unwanted-alga would die if the water content was below 25% after desiccation.When the water content of the P.haitanensis thallus was 10%,culture them after being stored at a low temperature of 20 for 30 days,then the survival rate would reach up to 99%~100%.If the water ratio was below 10%,then the survival rate would belower than 30%,and death even occurred.When the P.haitanensis thallus was stored with the water content ratio higher or lower than 10%~15% under low temperature,both its survival rate and the rate of weight gain when cultured after cold preservation would get aff ected.However,cold preser vation duration would bring a 100% death rate to the large scale unwanted-alga.Therefore,the ways of desiccation and cold preservation could effectively kill the unwanted-algas that have competitive relations with P.haitanensis thallus,which could be applied to raising the yield of P.haitanensis in practice.
2007, 29(2): 137-142.
Abstract:
The concept of candidate particle list is introduced in the MPS gridless numerical method to generate neighboring particle listmatrix,which reduces the CPU time to 1/11 of the case before the int roduction.The Bi-CGSTAB algorithm is applied to solving the pressure Poisson equation,by which the solving speed is significantly accelerated.Propagations of solitary waves over a numerical flume and the interaction with a vertical wall are simulated.The simulated results of water surface elevation are in good agreement with the analytical solution as well as the measured data.The predicted maxim um values of the run-up of solitary waves with various relative incident wave heights agree well with the measured results.
The concept of candidate particle list is introduced in the MPS gridless numerical method to generate neighboring particle listmatrix,which reduces the CPU time to 1/11 of the case before the int roduction.The Bi-CGSTAB algorithm is applied to solving the pressure Poisson equation,by which the solving speed is significantly accelerated.Propagations of solitary waves over a numerical flume and the interaction with a vertical wall are simulated.The simulated results of water surface elevation are in good agreement with the analytical solution as well as the measured data.The predicted maxim um values of the run-up of solitary waves with various relative incident wave heights agree well with the measured results.
2007, 29(2): 143-149.
Abstract:
2007, 29(2): 150-155.
Abstract:
2007, 29(2): 156-160.
Abstract:
2007, 29(2): 161-166.
Abstract:
2007, 29(2): 167-172.
Abstract:
2007, 29(2): 173-178.
Abstract:
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