2004 Vol. 26, No. 5
Display Method:
2004, 26(5): 1-11.
Abstract:
A detailed analysis and comparison of 7 represented altimeter model functions are presented,which have been published in the open literature,based on the collocted and coincident data between TOPEX/Poseidon altimeter and buoy observations.It is shown that the analytical algorithm considered the effect of wave state is superior to this empirical one as a whole.The issue of deriving wave period from altimeter is also discussed,and the results scatter largely.The possible way of improving wave-period algorithm is suggested.
A detailed analysis and comparison of 7 represented altimeter model functions are presented,which have been published in the open literature,based on the collocted and coincident data between TOPEX/Poseidon altimeter and buoy observations.It is shown that the analytical algorithm considered the effect of wave state is superior to this empirical one as a whole.The issue of deriving wave period from altimeter is also discussed,and the results scatter largely.The possible way of improving wave-period algorithm is suggested.
2004, 26(5): 12-22.
Abstract:
Using the improved ECOM model and coupling the sediment transpor tequation,the impacts of change of river discharge and sea level on estuarine turbidity maximum zone are studied.The estuarine turbidity maximum zone locates at the stagnation point.Both the upper-stream and lower-stream residual currents at low layers convey sediments to the stagnation point that induces the convergence of sediments,and the upwelling current induced by the convergence of flow field makes sediment difficult to settle down near the stagnation point.Because higher salt water brought by the saltwater intrusion lies in the bottom layer of the north coast,its baroclinic effect induces the transverse current at bottom layer flows from north to south which advects horizontally the high concentration sediments from north to south coast,it makes the turbidity maximum zone lie in the bottom of south coast.It is necessary for using a three dimension sediment transport model to study estuarine turbidity maximum zone.In the case of river discharge increase,compared with the case of control experiment,the land-ward density induced current at bottom layer reduces,the stagnation point moves downstream that makes the turbidity maximum zone move down-stream.The suspended sediment concentration at the center of the turbidity maximum zone and near the sand bar tends to increase because of the sediment addition from upstream.In the case of river discharge decrease,the variation tendencies of estuarine circulation,saltwater intrusion and turbidity maximum zone are in contrast with the results of river discharge increase.In the case of rise of sea level,the land-ward density induced current near sand bar enhances,the stagnation point moves upstream that makes the turbidity maximum zone move upstream.The sediment concentrations of turbidity maximum zone tends to be higher,but the sediment concentration at sand bar tends to be lower.The variations of change of river discharge and sea level have obvious impact on the turbidity maximum zone.
Using the improved ECOM model and coupling the sediment transpor tequation,the impacts of change of river discharge and sea level on estuarine turbidity maximum zone are studied.The estuarine turbidity maximum zone locates at the stagnation point.Both the upper-stream and lower-stream residual currents at low layers convey sediments to the stagnation point that induces the convergence of sediments,and the upwelling current induced by the convergence of flow field makes sediment difficult to settle down near the stagnation point.Because higher salt water brought by the saltwater intrusion lies in the bottom layer of the north coast,its baroclinic effect induces the transverse current at bottom layer flows from north to south which advects horizontally the high concentration sediments from north to south coast,it makes the turbidity maximum zone lie in the bottom of south coast.It is necessary for using a three dimension sediment transport model to study estuarine turbidity maximum zone.In the case of river discharge increase,compared with the case of control experiment,the land-ward density induced current at bottom layer reduces,the stagnation point moves downstream that makes the turbidity maximum zone move down-stream.The suspended sediment concentration at the center of the turbidity maximum zone and near the sand bar tends to increase because of the sediment addition from upstream.In the case of river discharge decrease,the variation tendencies of estuarine circulation,saltwater intrusion and turbidity maximum zone are in contrast with the results of river discharge increase.In the case of rise of sea level,the land-ward density induced current near sand bar enhances,the stagnation point moves upstream that makes the turbidity maximum zone move upstream.The sediment concentrations of turbidity maximum zone tends to be higher,but the sediment concentration at sand bar tends to be lower.The variations of change of river discharge and sea level have obvious impact on the turbidity maximum zone.
2004, 26(5): 23-33.
Abstract:
The wave model SWAN is applied to the waters around the Changjiang Estuary for calculating typhoon waves.Curvilinear grids are adopted due to the complicacy of coastal shapes and topographies in the Changjiang Estuary.In order to approve that SWAN wave model in curvilinear grids is suitable for complicated topographies,experiment data of wave basin in the University of Delaware,U.S.,are used to test the behavior of the model.Results show that calculating precision can be improved in the model by using curvilinear grids,not adding much calculating quantity simultaneously.Typhoon waves around the waters of the Changjiang Estuary are numerically simulated under the weather of Typhoon Rusa and Typhoon Sinlaku.The verifications of field data at the buoy show that the calculated significant wave heights accord well with the observed ones.Distributions of typhoon waves in the Changjiang Estuary are synthetically analyzed.In conclusion,the SWAN wave model can preferably reflect the distributions of typhoon waves around the waters of the Changjiang Estuary.
The wave model SWAN is applied to the waters around the Changjiang Estuary for calculating typhoon waves.Curvilinear grids are adopted due to the complicacy of coastal shapes and topographies in the Changjiang Estuary.In order to approve that SWAN wave model in curvilinear grids is suitable for complicated topographies,experiment data of wave basin in the University of Delaware,U.S.,are used to test the behavior of the model.Results show that calculating precision can be improved in the model by using curvilinear grids,not adding much calculating quantity simultaneously.Typhoon waves around the waters of the Changjiang Estuary are numerically simulated under the weather of Typhoon Rusa and Typhoon Sinlaku.The verifications of field data at the buoy show that the calculated significant wave heights accord well with the observed ones.Distributions of typhoon waves in the Changjiang Estuary are synthetically analyzed.In conclusion,the SWAN wave model can preferably reflect the distributions of typhoon waves around the waters of the Changjiang Estuary.
2004, 26(5): 34-44.
Abstract:
Based on the 4 synthetic cruise CTD data in the period of spring and summer from June 2000 to June 2002,it is revealed that there exists intrusion phenomena of low salinity water (LSW) in the region of stratification outside the northern Jiangsu Shoal(NJS) and nearshore around Chengshantou-Shidao (CS).The LSW intrudes much wide and strong as long as the stratification strength and varies with the years.The tongue like LSW intrudes northeastward and southwestward respectively from NJS and CS.The former is wide and strong,while the latter is relatively weak.The LSW is caused by the intrusion of the fresh coastal water and has a close relationship with the distinguished tidal front in that area.
Based on the 4 synthetic cruise CTD data in the period of spring and summer from June 2000 to June 2002,it is revealed that there exists intrusion phenomena of low salinity water (LSW) in the region of stratification outside the northern Jiangsu Shoal(NJS) and nearshore around Chengshantou-Shidao (CS).The LSW intrudes much wide and strong as long as the stratification strength and varies with the years.The tongue like LSW intrudes northeastward and southwestward respectively from NJS and CS.The former is wide and strong,while the latter is relatively weak.The LSW is caused by the intrusion of the fresh coastal water and has a close relationship with the distinguished tidal front in that area.
2004, 26(5): 45-54.
Abstract:
The characterization of track and intensity change of tropical cyclone is analyzed that induces remarkable storm surge.It is shown that there are three kinds of track that affect Shanghai,they are westward moving of landfalling at the east coast of Zhejiang Province,northward moving inshore and positively hit Shanghai on the sea.The change in the tropical cyclone intensity as it passes the area near to Shanghai is remarkable.In general,the minimum surface level pressure of tropical cyclene center near to Shanghai is greater than 920 hPa.The probable maximum water level in Shanghai area estimated using the statistical method is about 210 cm.This is not suitable for the estimation of water level in Shanghai due to the lack of statistical method for the description of small probability.The results of numerical simulation indicate that considering the combination of probable tracks,estimated intensities and various velocities of tropical cyclone movement,the probable maximum water levels are calculated using a three-dimensional numerical model.The result indicates that the probable maximum water level appears when the track of TC 5612 is set to move 2°in latitude and the minimum sea surface pressure takes the lowest value in Shanghai.The estimated probable water level is 787cm.
The characterization of track and intensity change of tropical cyclone is analyzed that induces remarkable storm surge.It is shown that there are three kinds of track that affect Shanghai,they are westward moving of landfalling at the east coast of Zhejiang Province,northward moving inshore and positively hit Shanghai on the sea.The change in the tropical cyclone intensity as it passes the area near to Shanghai is remarkable.In general,the minimum surface level pressure of tropical cyclene center near to Shanghai is greater than 920 hPa.The probable maximum water level in Shanghai area estimated using the statistical method is about 210 cm.This is not suitable for the estimation of water level in Shanghai due to the lack of statistical method for the description of small probability.The results of numerical simulation indicate that considering the combination of probable tracks,estimated intensities and various velocities of tropical cyclone movement,the probable maximum water levels are calculated using a three-dimensional numerical model.The result indicates that the probable maximum water level appears when the track of TC 5612 is set to move 2°in latitude and the minimum sea surface pressure takes the lowest value in Shanghai.The estimated probable water level is 787cm.
2004, 26(5): 55-62.
Abstract:
Water transparency (Secchi disc depth) is a basic parameter that describes the optical property of water.A semi-analytical inversing model of water transparency was provided using the theory of radiative transfer in water.The accuracy of this semi-analytical inversing model was validated by using the larger-scale in-situ data,and the result shows that the correlation is 0.84 with the relative error 22.6% and absolute error 4.7 m.Finally,using this inversing model of water transparency and SeaWiFS data,some time serial images of water transparency distribution were generated with monthly average in China seas in 1999.
Water transparency (Secchi disc depth) is a basic parameter that describes the optical property of water.A semi-analytical inversing model of water transparency was provided using the theory of radiative transfer in water.The accuracy of this semi-analytical inversing model was validated by using the larger-scale in-situ data,and the result shows that the correlation is 0.84 with the relative error 22.6% and absolute error 4.7 m.Finally,using this inversing model of water transparency and SeaWiFS data,some time serial images of water transparency distribution were generated with monthly average in China seas in 1999.
2004, 26(5): 63-73.
Abstract:
Based on the data obtained by field survey and experiments of the Zhujiang River Estuary during July 17~28,1999,the cycle,regeneration and restriction of N and P in water masses are studied.The results show that there is a large content of N in the Zhujiang River Estuary waters,and it belongs to a high N/P area in the world.With the water mass transported from river to sea,the speciation and concentration of N and P present a violent variation in the waters.Among others,there is new supply on the N,and the supplemental volume may be even larger than the absorbing capacity of plankton photosynthesis somew here.Because of plankton absorbing,migration action of species variation and being intruded and being diluted by the seawater,the concentration of DIN was so constantly reduced and that the N/P was even lower than 16 off the Zhujiang River Estuary.The variation of concentration of PO43- become mirror image each other between the surface layer and the bottom layer water,which indicates that both the directions of biogeochemicalaction of P are contrary.The plankton absorbing is primary process in the surface layer,but the regeneration takes precedence in the middle layer and the bottom layer.Comparatively speaking,one point is the migrationratio of DIN is greater than DIP and the other is the turbidity (or light),P and N are the limit factors of the primary productivity in three areas (from the river gate to the maximum turbidity zone,middle waters of the estuary and off the estuary) respectively.The results of incubation show that the bloom of plankton lead to the considerabl decrease of concentration of DIN,but the concentration of PO43- is in a small scope vibration and keeps a more steady concentration level.It is inferred that the cycle and regeneration of P are more rapid than N,and the regeneration of P can direct supply primary product in euphotic and become a factor bringing to the plankton bloom in the waters,but the reason of the bloom passing away is the DIN being used up in the end.Through contrast study of biogeochemical cycle of N and P,similarities and differences of the process of cycle and regeneration between N and P are explicated,and infer potentiality of the denitrification action in the hypoxia area is inferred.
Based on the data obtained by field survey and experiments of the Zhujiang River Estuary during July 17~28,1999,the cycle,regeneration and restriction of N and P in water masses are studied.The results show that there is a large content of N in the Zhujiang River Estuary waters,and it belongs to a high N/P area in the world.With the water mass transported from river to sea,the speciation and concentration of N and P present a violent variation in the waters.Among others,there is new supply on the N,and the supplemental volume may be even larger than the absorbing capacity of plankton photosynthesis somew here.Because of plankton absorbing,migration action of species variation and being intruded and being diluted by the seawater,the concentration of DIN was so constantly reduced and that the N/P was even lower than 16 off the Zhujiang River Estuary.The variation of concentration of PO43- become mirror image each other between the surface layer and the bottom layer water,which indicates that both the directions of biogeochemicalaction of P are contrary.The plankton absorbing is primary process in the surface layer,but the regeneration takes precedence in the middle layer and the bottom layer.Comparatively speaking,one point is the migrationratio of DIN is greater than DIP and the other is the turbidity (or light),P and N are the limit factors of the primary productivity in three areas (from the river gate to the maximum turbidity zone,middle waters of the estuary and off the estuary) respectively.The results of incubation show that the bloom of plankton lead to the considerabl decrease of concentration of DIN,but the concentration of PO43- is in a small scope vibration and keeps a more steady concentration level.It is inferred that the cycle and regeneration of P are more rapid than N,and the regeneration of P can direct supply primary product in euphotic and become a factor bringing to the plankton bloom in the waters,but the reason of the bloom passing away is the DIN being used up in the end.Through contrast study of biogeochemical cycle of N and P,similarities and differences of the process of cycle and regeneration between N and P are explicated,and infer potentiality of the denitrification action in the hypoxia area is inferred.
2004, 26(5): 74-82.
Abstract:
The composition,assemblage and distribution characteristics of heavy minerals from 63 to 125 μm grainsizes in surface sediment from the Xinghua Bay (17 stations) are studied.And then,matter source of silt and relationship of heavy minerals with sedimentary environment are discussed.The results show that there are 37 kinds of heavy minerals and the average content of them is 12.08% which exceeds 6% compared with the Meizhou Bay (5.67%).The dominant minerals are magnetite,hornblende,epidote,ilmenite,hematite,limonite,zircon and so on.Mineral kinds reveal that silt in this bay mainly comes from fluvial input and eroded products of bedrock in circumjacent land and islands of the Xinghua Bay,however,the matter origin from outside area of this bay is less.The Xinghua Bay can be divided into 4 mineral assemblage zones based on heavy mineral contents and distribution characteristics,which are not only related to matter source,but also controlled by hydrodynamic condition and sedimentary environment in the Xinghua Bay.
The composition,assemblage and distribution characteristics of heavy minerals from 63 to 125 μm grainsizes in surface sediment from the Xinghua Bay (17 stations) are studied.And then,matter source of silt and relationship of heavy minerals with sedimentary environment are discussed.The results show that there are 37 kinds of heavy minerals and the average content of them is 12.08% which exceeds 6% compared with the Meizhou Bay (5.67%).The dominant minerals are magnetite,hornblende,epidote,ilmenite,hematite,limonite,zircon and so on.Mineral kinds reveal that silt in this bay mainly comes from fluvial input and eroded products of bedrock in circumjacent land and islands of the Xinghua Bay,however,the matter origin from outside area of this bay is less.The Xinghua Bay can be divided into 4 mineral assemblage zones based on heavy mineral contents and distribution characteristics,which are not only related to matter source,but also controlled by hydrodynamic condition and sedimentary environment in the Xinghua Bay.
2004, 26(5): 83-93.
Abstract:
According to the result of paleomagnetism inversed from magnetic anomalies of seamounts in the South China Sea,China between its eastern and southwestern subbasins there is much difference in the movement form and active age.There is a transform fault of NNW-trending with compressive left-slip——"the central fault of the South China Sea Basin" between two subbasins.Combined with analysis and interpretation for the given results of geological and geophysical research,it can be concluded that the South China Sea Basin was developed between the ancient South China Sea and the southern edge of South China terrain.The development of the South China Sea can be divided into four stages as follows:Stage Ⅰ,in Eocene the ancient South China Sea was split into two parts with the formation of its fault;Stage Ⅱ,in Oligocene the eastern subbasin began to develop with rupture;Stage Ⅲ,in Miocene the southwestern subbasin began to develop with rift;Stage Ⅳ,the South China Sea revolved and the ancient South China Sea closed.
According to the result of paleomagnetism inversed from magnetic anomalies of seamounts in the South China Sea,China between its eastern and southwestern subbasins there is much difference in the movement form and active age.There is a transform fault of NNW-trending with compressive left-slip——"the central fault of the South China Sea Basin" between two subbasins.Combined with analysis and interpretation for the given results of geological and geophysical research,it can be concluded that the South China Sea Basin was developed between the ancient South China Sea and the southern edge of South China terrain.The development of the South China Sea can be divided into four stages as follows:Stage Ⅰ,in Eocene the ancient South China Sea was split into two parts with the formation of its fault;Stage Ⅱ,in Oligocene the eastern subbasin began to develop with rupture;Stage Ⅲ,in Miocene the southwestern subbasin began to develop with rift;Stage Ⅳ,the South China Sea revolved and the ancient South China Sea closed.
2004, 26(5): 94-105.
Abstract:
The surface sediments in the eastern South China Sea can be divided into 11 types based on the data of sediment color,grain size analysis,chemical and mineral compositions,microfossils,etc.These sediment types are named as clayey silt with rock debris,shell sand,clayey silt,calcareous clay,calcareous ooze,foraminifer ooze,pelagic clay,silty clay with micro-manganese nodules,siliceous clay,siliceous clay with volcanic ash,silty clay with volcanic ash.These sediments can be attributed into terrigenous,biogenic and volcanogenic,according to their material source and genetic environments of sediments.Of which,terrigenous sediments cover 50% area of sea bottom in the study area,calcareous debris 20%,siliceous debris and volcanogenic sediments 15% respectively.Under being controlled and affected by the factors such as materialsource,seabed feature,volcanic eruption and organism activity,hydraulic conditions,as well as the different depositional environments,the brown sediments are dominated (60.68%),the second is the grey sediments(38.20%),the last is the yellow sediments(1.12%) in the study area.In the sea area of between south of Taiwan Province of China and 17°N,the sediments consist mainly of terrigenous constituents;in the west sea area of the Bashi Channel,the coarse sediments are dominated with sandstone rock and gravel;in the east sea area of Dongsha Islands,calcareous debr is are enriched;in the central and western parts,the sediments are rich in the micro-mang anese nodules;siliceous sediments are widely distributed in the southern and central areas because of deep waters;in the southern part and the north edge of Liyue Bank(Liyue Reef Shoal),sediments are calcareous ooze due to be affected by large quantities of detrital corals.
The surface sediments in the eastern South China Sea can be divided into 11 types based on the data of sediment color,grain size analysis,chemical and mineral compositions,microfossils,etc.These sediment types are named as clayey silt with rock debris,shell sand,clayey silt,calcareous clay,calcareous ooze,foraminifer ooze,pelagic clay,silty clay with micro-manganese nodules,siliceous clay,siliceous clay with volcanic ash,silty clay with volcanic ash.These sediments can be attributed into terrigenous,biogenic and volcanogenic,according to their material source and genetic environments of sediments.Of which,terrigenous sediments cover 50% area of sea bottom in the study area,calcareous debris 20%,siliceous debris and volcanogenic sediments 15% respectively.Under being controlled and affected by the factors such as materialsource,seabed feature,volcanic eruption and organism activity,hydraulic conditions,as well as the different depositional environments,the brown sediments are dominated (60.68%),the second is the grey sediments(38.20%),the last is the yellow sediments(1.12%) in the study area.In the sea area of between south of Taiwan Province of China and 17°N,the sediments consist mainly of terrigenous constituents;in the west sea area of the Bashi Channel,the coarse sediments are dominated with sandstone rock and gravel;in the east sea area of Dongsha Islands,calcareous debr is are enriched;in the central and western parts,the sediments are rich in the micro-mang anese nodules;siliceous sediments are widely distributed in the southern and central areas because of deep waters;in the southern part and the north edge of Liyue Bank(Liyue Reef Shoal),sediments are calcareous ooze due to be affected by large quantities of detrital corals.
2004, 26(5): 106-115.
Abstract:
On the basis of the results of analyses of charcoal debris,spores and pollen,and chronologic datings in a natural profile,the climatic changes during the last 2 500 a are reconstructed.According to comparison of the results of analysis with the detailed historical records,the abnormal peak values of charcoal content in the profile are related to the population booms and fire hazards in time sequence in the history.The changes of some species of spores and pollen might have been the results of human cultivation.The result indicates that the influence of human activities can be distinguished from natural evolution processes by improving the resolution of analysis,which is significant to the improvement of environment and the restoration of ecosystem.
On the basis of the results of analyses of charcoal debris,spores and pollen,and chronologic datings in a natural profile,the climatic changes during the last 2 500 a are reconstructed.According to comparison of the results of analysis with the detailed historical records,the abnormal peak values of charcoal content in the profile are related to the population booms and fire hazards in time sequence in the history.The changes of some species of spores and pollen might have been the results of human cultivation.The result indicates that the influence of human activities can be distinguished from natural evolution processes by improving the resolution of analysis,which is significant to the improvement of environment and the restoration of ecosystem.
2004, 26(5): 116-122.
Abstract:
The fragments of 350 bp in 28S rRNA from the closely related monogenea of trematoda,Neobenedenia girellae and N.melleni were obtained by polymerase chain reaction (PCR) amplified using a couple of special primers and then sequenced.The results show that the comparison of 28S rRNA sequences,with only a base varies in 337 bp accounting for 0.3% genetic difference,the relative species N.girellae and N.melleni parasitized on the different fishes in different farms display that they possess very high genetic similarity of 99.7%,higher than that of 99.41% for the single species N.melleni cultured in different area,and the intraspecific divergence of N.melleni is 0.59%.Meanwhile,the interspecific differences between the two Neobenedenia and three Benedenia (i.e.B.lutjani,B.rohdei and B.seriolae) range from 2.08% to 11.73%.In addition,UPGMA and MP molecular phylogenetic trees were constructed and proved to be consistent with each other.Though the morphological characteristics and the results of genetic diversity for the two Neobenedenia show the high similarity,whether they belong to a single species or not is still undefined,the more genes of them should be further investigated,combining with the systematicall and detailed morphological study.
The fragments of 350 bp in 28S rRNA from the closely related monogenea of trematoda,Neobenedenia girellae and N.melleni were obtained by polymerase chain reaction (PCR) amplified using a couple of special primers and then sequenced.The results show that the comparison of 28S rRNA sequences,with only a base varies in 337 bp accounting for 0.3% genetic difference,the relative species N.girellae and N.melleni parasitized on the different fishes in different farms display that they possess very high genetic similarity of 99.7%,higher than that of 99.41% for the single species N.melleni cultured in different area,and the intraspecific divergence of N.melleni is 0.59%.Meanwhile,the interspecific differences between the two Neobenedenia and three Benedenia (i.e.B.lutjani,B.rohdei and B.seriolae) range from 2.08% to 11.73%.In addition,UPGMA and MP molecular phylogenetic trees were constructed and proved to be consistent with each other.Though the morphological characteristics and the results of genetic diversity for the two Neobenedenia show the high similarity,whether they belong to a single species or not is still undefined,the more genes of them should be further investigated,combining with the systematicall and detailed morphological study.
2004, 26(5): 123-131.
Abstract:
The diurnal vertical migration of planktonic Ostracoda is studied based on the analysis of stratified samples of zooplanktons in the IONESS system. The whole taxa of planktonic Ostracoda migrates vertically and diurnally, its greatest abundance by day occurs at 200~300 m layer and decreases upward and at night occurs at 50~100 m layer but increases upward. Numerous species at the layers lower than the working layer ( 0~1 000 m) migrate upward at night to the layers shallower than 1 000 m. As a result, the total number of species in the working layer in creases sharply from 49 species by day to 78 species at night, with an increase amplitude of 60%. The number of species increases rather distinctly at various layers, firstly at the layer of 750~1 000 m with an amplitude of 150% and secondly at the layer of 50~100 m with an amplitude of 125%. Different planktonic Ostracoda takes different mode of diurnal vertical migration, agreat majority of species take the mode of upward migration at night, less number of species take insensitive mode and a fewer number of species take the mode of downward migration at night. The diurnal vertical migration of planktonic Ostracoda, which is distinct in this regard, is restricted in a certain water depth, demonstrating its features of stratified distribution. Ostracoda may be classified into four modes of distribution, namely, eurybathy distribution mode, upper layer distribution mode, mid-layer distribution mode and lower-layer distribution mode.
The diurnal vertical migration of planktonic Ostracoda is studied based on the analysis of stratified samples of zooplanktons in the IONESS system. The whole taxa of planktonic Ostracoda migrates vertically and diurnally, its greatest abundance by day occurs at 200~300 m layer and decreases upward and at night occurs at 50~100 m layer but increases upward. Numerous species at the layers lower than the working layer ( 0~1 000 m) migrate upward at night to the layers shallower than 1 000 m. As a result, the total number of species in the working layer in creases sharply from 49 species by day to 78 species at night, with an increase amplitude of 60%. The number of species increases rather distinctly at various layers, firstly at the layer of 750~1 000 m with an amplitude of 150% and secondly at the layer of 50~100 m with an amplitude of 125%. Different planktonic Ostracoda takes different mode of diurnal vertical migration, agreat majority of species take the mode of upward migration at night, less number of species take insensitive mode and a fewer number of species take the mode of downward migration at night. The diurnal vertical migration of planktonic Ostracoda, which is distinct in this regard, is restricted in a certain water depth, demonstrating its features of stratified distribution. Ostracoda may be classified into four modes of distribution, namely, eurybathy distribution mode, upper layer distribution mode, mid-layer distribution mode and lower-layer distribution mode.
2004, 26(5): 132-138.
Abstract:
The quantitative distribution of planktonic Amphipoda in the East China Sea is analyzed and studied on the relation of it with environmental factors and mackerel and scad fishing grounds is studied.The result shows that biomass is characterized by great seasonal and interannual variety during the passing three decades.The distribution of planktonic Amphipoda basically reflects the movement,decay and intensification of the different water systems in the survey area.
The quantitative distribution of planktonic Amphipoda in the East China Sea is analyzed and studied on the relation of it with environmental factors and mackerel and scad fishing grounds is studied.The result shows that biomass is characterized by great seasonal and interannual variety during the passing three decades.The distribution of planktonic Amphipoda basically reflects the movement,decay and intensification of the different water systems in the survey area.
2004, 26(5): 139-149.
Abstract:
Six cruises were carried out in the north of Jiaozhou Bay from March 1995 to January 1996.The Q statistics,a measure of the inter-quartile slope of the cumulative species abundance curve,was applied to studying diversity of phytoplankton community in the survey area.The results show that Q statistics of phytoplankton community is higher in summer and autumn than that in winter and spring.Comparing with the other common biodiversity indices of phytoplankton community,such as speciesr ichness,Marg alef's index,Shannon's index,Simpson's index and Pielou's evenness,the Q statistics is a good index.the Q statistics afforded a greater degree of discrimination than any the other indices,it can described species abundance in the inter-quartile region of species abundance distribution,and is robust against variable sample size.It is also a robust and useful diversity measure which does not require the fitting of a species abundance model.Using Q statistics in analysis of phytoplankton community diversity is strongly recommended.
Six cruises were carried out in the north of Jiaozhou Bay from March 1995 to January 1996.The Q statistics,a measure of the inter-quartile slope of the cumulative species abundance curve,was applied to studying diversity of phytoplankton community in the survey area.The results show that Q statistics of phytoplankton community is higher in summer and autumn than that in winter and spring.Comparing with the other common biodiversity indices of phytoplankton community,such as speciesr ichness,Marg alef's index,Shannon's index,Simpson's index and Pielou's evenness,the Q statistics is a good index.the Q statistics afforded a greater degree of discrimination than any the other indices,it can described species abundance in the inter-quartile region of species abundance distribution,and is robust against variable sample size.It is also a robust and useful diversity measure which does not require the fitting of a species abundance model.Using Q statistics in analysis of phytoplankton community diversity is strongly recommended.
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