2011 Vol. 33, No. 5
Display Method:
2011, 33(5): 1-8.
Abstract:
The biogeochemical processes of benthic boundary layer in large river estuary and coastal area impact the transport and transformation of terrestrial materials and their seaward flux.It is the key problems of studies of land-ocean interaction,carbon sources and sinks in oceans and the nitrogen and phosphorus cycle.The advances and future outlook in research on biogeochemical process in benthic boundary layer of estuary and its adjacent sea area were analyzed and summarized with highlighting the features and functions of mobile muds in benthic boundary layer and the role of microorganisms in the biogeochemical processes therein.
The biogeochemical processes of benthic boundary layer in large river estuary and coastal area impact the transport and transformation of terrestrial materials and their seaward flux.It is the key problems of studies of land-ocean interaction,carbon sources and sinks in oceans and the nitrogen and phosphorus cycle.The advances and future outlook in research on biogeochemical process in benthic boundary layer of estuary and its adjacent sea area were analyzed and summarized with highlighting the features and functions of mobile muds in benthic boundary layer and the role of microorganisms in the biogeochemical processes therein.
2011, 33(5): 9-22.
Abstract:
Interannual variations of the subtropical-tropical pycnocline mass exchange in the Pacific Ocean and its mechanisms are investigated by using a global oceanic general circulation model forcing with three wind stress datasets. The results show that the subtropical-tropical pycnocline mass exchange in the Pacific Ocean varies significantly on interannual time scales, and the variation of the interior pycnocline transport is found to be anticorrelated to the boundary pycnocline transport and the former is generally compensated by the latter. Comparison between two hemispheres shows that the variabilities of boundary and interior transports of southern hemisphere are more pronounced than those of northern hemisphere, also the correlation coefficients and compensation rate between boundary and interior transports of southern hemisphere are larger than those of northern hemisphere, but the variability of the net transport of southern hemisphere is smaller than that of northern hemisphere. In both hemispheres, the counteracting tendency of the boundary and interior transports is primarily due to the propagation of baroclinic Rossby waves induced by the changes of the off-equatorial wind stress curl. The sensitive experiments show that the net pycnocline transports in both the northern and southern hemisphere are mainly attributed to the variability of near-equatorial zonal wind stress, whereas the effect of the propagation of baroclinic Rossby waves only plays a second role and could not results in such a compensation rate in each hemisphere.
Interannual variations of the subtropical-tropical pycnocline mass exchange in the Pacific Ocean and its mechanisms are investigated by using a global oceanic general circulation model forcing with three wind stress datasets. The results show that the subtropical-tropical pycnocline mass exchange in the Pacific Ocean varies significantly on interannual time scales, and the variation of the interior pycnocline transport is found to be anticorrelated to the boundary pycnocline transport and the former is generally compensated by the latter. Comparison between two hemispheres shows that the variabilities of boundary and interior transports of southern hemisphere are more pronounced than those of northern hemisphere, also the correlation coefficients and compensation rate between boundary and interior transports of southern hemisphere are larger than those of northern hemisphere, but the variability of the net transport of southern hemisphere is smaller than that of northern hemisphere. In both hemispheres, the counteracting tendency of the boundary and interior transports is primarily due to the propagation of baroclinic Rossby waves induced by the changes of the off-equatorial wind stress curl. The sensitive experiments show that the net pycnocline transports in both the northern and southern hemisphere are mainly attributed to the variability of near-equatorial zonal wind stress, whereas the effect of the propagation of baroclinic Rossby waves only plays a second role and could not results in such a compensation rate in each hemisphere.
2011, 33(5): 23-31.
Abstract:
Using CCSM3 model of NCAR,this study examines the results of control run and 130yr simulation run form year 1870 to 1999. The temperature varying trend of the Pacific Ocean area and the spatial-temporal structure of the North Pacific Decadal Oscillation (PDO) are analyzed by comparing model output with corresponding reanalysis data. The results indicate that the model simulates well many features of the observed PDO, the spatial distribution pattern of sea surface temperature anomaly are similar to the typical PDO. Especially when the trend of CO2 is considered in simulation, the three important phase-changing of SSTA in North Pacific Ocean in the 20th are well reproduced. The position of two core of temperature anomaly in subsurface are more eastern and deeper, and the temperature difference between east and west are reduced. The increasing of CO2 play an important role in elongating the period and phase-changing of simulated PDO, the position and intensity are also affected.
Using CCSM3 model of NCAR,this study examines the results of control run and 130yr simulation run form year 1870 to 1999. The temperature varying trend of the Pacific Ocean area and the spatial-temporal structure of the North Pacific Decadal Oscillation (PDO) are analyzed by comparing model output with corresponding reanalysis data. The results indicate that the model simulates well many features of the observed PDO, the spatial distribution pattern of sea surface temperature anomaly are similar to the typical PDO. Especially when the trend of CO2 is considered in simulation, the three important phase-changing of SSTA in North Pacific Ocean in the 20th are well reproduced. The position of two core of temperature anomaly in subsurface are more eastern and deeper, and the temperature difference between east and west are reduced. The increasing of CO2 play an important role in elongating the period and phase-changing of simulated PDO, the position and intensity are also affected.
2011, 33(5): 32-38.
Abstract:
Prydz Bay is almost partially covered by sea ice all year. The distribution of sea ice and its annual variation are controlled mainly by the meteorological conditions and ocean currents. To model the seasonal variation of sea ice, a coupled ice-ocean model has been developed. The ocean model based on the MITgcm, and the ice model is based on the viscous-plastic rheology of Hibler and Winton three-layer reformulated thermodynamics. The model domain encompasses Prydz Bay (75°~55°S, 50°~100°E,) and with a grid resolution of (1/6)°×(1/12)° degree (latitude/longitude, average 6 km). Forcing fields are computed from 6-hourly NCEP reanalysis. The main features of the model simulations include an increasing ice cover from March to August, an approximately constant ice cover from August to November and a decreasing ice cover from November to February. In mid-September, polynyas start to develop at three coastal regions, temporal and spatial characteristics of the three polynyas are well reproduced and compare with available satellite data. Thick ice up to 3 m is piled up at the east end of the West Ice Shelf due to westward alongcoast current.
Prydz Bay is almost partially covered by sea ice all year. The distribution of sea ice and its annual variation are controlled mainly by the meteorological conditions and ocean currents. To model the seasonal variation of sea ice, a coupled ice-ocean model has been developed. The ocean model based on the MITgcm, and the ice model is based on the viscous-plastic rheology of Hibler and Winton three-layer reformulated thermodynamics. The model domain encompasses Prydz Bay (75°~55°S, 50°~100°E,) and with a grid resolution of (1/6)°×(1/12)° degree (latitude/longitude, average 6 km). Forcing fields are computed from 6-hourly NCEP reanalysis. The main features of the model simulations include an increasing ice cover from March to August, an approximately constant ice cover from August to November and a decreasing ice cover from November to February. In mid-September, polynyas start to develop at three coastal regions, temporal and spatial characteristics of the three polynyas are well reproduced and compare with available satellite data. Thick ice up to 3 m is piled up at the east end of the West Ice Shelf due to westward alongcoast current.
2011, 33(5): 39-46.
Abstract:
The monthly Sea Surface Temperature (SST) data and the Precipitation Reconstruction data set during the period from 1967 to 2009 are used to analyze the spatial-temporal distribution of sea surface temperature in the Joining Area of Asia and Indian-Pacific Ocean (AIPO) and its impacts on precipitation in China, through methods of the Empirical Orthogonal Function (EOF) and correlation analysis. The results show that the first eigenvector (EOF1) has uniform mode and the first time coefficient behaves as significant interdecadal change. On the interdecadal time-scale, As the SST rises in the AIPO region, the SST in the North Pacific begins decrease, and reaches the lowest 11 months later. Additionally, the SST rises in the AIPO region would make the precipitation in the South China Sea (SCS) monsoon region and East Asia monsoon region increase, but reduce in the west of Qinghai-Tibet Plateau. The second eigenvector (EOF2) is featured with out-phase in the western Pacific and Eastern Indian Ocean (including SCS) and the second time coefficient displays evidently biennial and 4~5 years interannual oscillation. When the Niño 3.4 SST appears positive anomaly, there is positive SST anomaly in the Eastern Indian Ocean and negative anomaly in the western Pacific 4-month later. The warm SST in the western Pacific and the cold in the Eastern Indian Ocean would suppress the precipitation in the western North Pacific and enhance the precipitation in the Northeast and North China increase. Moreover, the effect of the AIPO SST on the precipitation in the north of China has at least 3 months leading relative to that on the western North Pacific precipitation.
The monthly Sea Surface Temperature (SST) data and the Precipitation Reconstruction data set during the period from 1967 to 2009 are used to analyze the spatial-temporal distribution of sea surface temperature in the Joining Area of Asia and Indian-Pacific Ocean (AIPO) and its impacts on precipitation in China, through methods of the Empirical Orthogonal Function (EOF) and correlation analysis. The results show that the first eigenvector (EOF1) has uniform mode and the first time coefficient behaves as significant interdecadal change. On the interdecadal time-scale, As the SST rises in the AIPO region, the SST in the North Pacific begins decrease, and reaches the lowest 11 months later. Additionally, the SST rises in the AIPO region would make the precipitation in the South China Sea (SCS) monsoon region and East Asia monsoon region increase, but reduce in the west of Qinghai-Tibet Plateau. The second eigenvector (EOF2) is featured with out-phase in the western Pacific and Eastern Indian Ocean (including SCS) and the second time coefficient displays evidently biennial and 4~5 years interannual oscillation. When the Niño 3.4 SST appears positive anomaly, there is positive SST anomaly in the Eastern Indian Ocean and negative anomaly in the western Pacific 4-month later. The warm SST in the western Pacific and the cold in the Eastern Indian Ocean would suppress the precipitation in the western North Pacific and enhance the precipitation in the Northeast and North China increase. Moreover, the effect of the AIPO SST on the precipitation in the north of China has at least 3 months leading relative to that on the western North Pacific precipitation.
2011, 33(5): 47-53.
Abstract:
During the process of typhoon, storm surges and waves are concomitant and interact with each other. Wave-induced radiation stress plays an important role on the nearshore.To get correct radiation stress, storm surge. The traditional 3rd generation sea wave model is time-consuming and can not meet the requirements of operational forecasting. On the basis of primitive expression of wave-induced radiation stress,a simplified radiation stress expression is deduced and can be easily added to the storm surge model. A practical storm surge model including the role of wave set-up in nearshore waters is proposed. The new model can not only improve the physical process of wave set-up and time-saving, but also obtain a more satisfactory result than the old one through two disastrous storm surge's simulation in Guangdong coastal areas.
During the process of typhoon, storm surges and waves are concomitant and interact with each other. Wave-induced radiation stress plays an important role on the nearshore.To get correct radiation stress, storm surge. The traditional 3rd generation sea wave model is time-consuming and can not meet the requirements of operational forecasting. On the basis of primitive expression of wave-induced radiation stress,a simplified radiation stress expression is deduced and can be easily added to the storm surge model. A practical storm surge model including the role of wave set-up in nearshore waters is proposed. The new model can not only improve the physical process of wave set-up and time-saving, but also obtain a more satisfactory result than the old one through two disastrous storm surge's simulation in Guangdong coastal areas.
2011, 33(5): 54-60.
Abstract:
A new model for calculating sound speed profile (SSP) structure, namely Layered Sound Speed Profile Model (LSSPM), is developed based on Munk model and Generalized Digital Environmental Model(GDEM). In this model, the SSP structure composed of mixed layer, thermocline, deep channel layer and deep isothermal layer is depicted respectively by a set of expressions with 9 coefficients, which have a concise and distinct form. The results of numerical experiments show that LSSPM can provide a precise calculation for SSP fitness, and can be applicable for both deep and shallow sea areas adjacent China.
A new model for calculating sound speed profile (SSP) structure, namely Layered Sound Speed Profile Model (LSSPM), is developed based on Munk model and Generalized Digital Environmental Model(GDEM). In this model, the SSP structure composed of mixed layer, thermocline, deep channel layer and deep isothermal layer is depicted respectively by a set of expressions with 9 coefficients, which have a concise and distinct form. The results of numerical experiments show that LSSPM can provide a precise calculation for SSP fitness, and can be applicable for both deep and shallow sea areas adjacent China.
2011, 33(5): 61-72.
Abstract:
The seasonal variation and the main controlling factors of the hydrological characteristics and biogenic elements at 36°N transect in the western Southern Huanghai Sea was illustrated,moreover,the important ecological behavior in the related sea area was also reflecting and indicated.The result showed that:(1)The Huanghai Sea Cold Water Mass(HSCWM)and the Huanghai Sea Warm Current(HSWC)at 36°N alternated seasonally;the water body under the thermocline in autumn was the mixed water which not only retained the characteristics of the Cold Water Mass,but also had the features of the warm water;a low-salinity cold water patch(Qingdao Cold Water Mass)existed in the west of the section in four seasons,and the seasonal variation of its location was closely related to the boundary of the HSCWM and HSWC.(2)The stratification,bio-chemical effect and vertical mixing process were the main factors influencing the distribution and seasonal variation of the biogenic elements;in autumn and winter,a high-nutrients area was found near the low-salinity cold water in the west of the section;the nutricline exited in the deep waters of the section and the sea area of the HSCWM in four seasons,which was closely related to the hydrological thermocline,water stability and bio-chemical effect.Meanwhile,a viewpoint was also proposed in this paper that the sea area of the HSCWM had the function of nutrients stored in summer and exported in winter.
The seasonal variation and the main controlling factors of the hydrological characteristics and biogenic elements at 36°N transect in the western Southern Huanghai Sea was illustrated,moreover,the important ecological behavior in the related sea area was also reflecting and indicated.The result showed that:(1)The Huanghai Sea Cold Water Mass(HSCWM)and the Huanghai Sea Warm Current(HSWC)at 36°N alternated seasonally;the water body under the thermocline in autumn was the mixed water which not only retained the characteristics of the Cold Water Mass,but also had the features of the warm water;a low-salinity cold water patch(Qingdao Cold Water Mass)existed in the west of the section in four seasons,and the seasonal variation of its location was closely related to the boundary of the HSCWM and HSWC.(2)The stratification,bio-chemical effect and vertical mixing process were the main factors influencing the distribution and seasonal variation of the biogenic elements;in autumn and winter,a high-nutrients area was found near the low-salinity cold water in the west of the section;the nutricline exited in the deep waters of the section and the sea area of the HSCWM in four seasons,which was closely related to the hydrological thermocline,water stability and bio-chemical effect.Meanwhile,a viewpoint was also proposed in this paper that the sea area of the HSCWM had the function of nutrients stored in summer and exported in winter.
2011, 33(5): 73-82.
Abstract:
Total organic carbon(TOC), CaCO3, total nitrogen (TN), particulate organic carbon(POC) and grain size in surface sediments of the western Taiwan Strait were analysed in 2005. TOC and CaCO3 contents varied in the ranges of 0.01~1.79 and 0.11~23.00 respectively. The average content of TOC in the surface sediments was 0.37±0.24 which larger than the TOC in the Southern Taiwan Strait ,but smaller than the TOC in the center and north of Taiwan Strait in 1980s. High level of TOC content was found near-shore and decreased seaward. Region with high and low value of CaCO3 had the scattering features. The average ratio C/N which indicated the mixed sources of organic materials was 10.12. The background relationship between TOC and TN was close. The power correlation between OC and grain size was suggested that grain size was a limiting factor for TOC. But there was not a good relation between grain size and CaCO3. TOC in sediment was not coupled with primary production in water in or around the upwelling area of the southern Taiwan Straint. After calculation, burial fluxes of carbon was 105 t/a in the sediments of the western Taiwan Strait. The terrestrial input, coastal current and upwelling significantly influenced the burial fluxes of carbon in the sediment.
Total organic carbon(TOC), CaCO3, total nitrogen (TN), particulate organic carbon(POC) and grain size in surface sediments of the western Taiwan Strait were analysed in 2005. TOC and CaCO3 contents varied in the ranges of 0.01~1.79 and 0.11~23.00 respectively. The average content of TOC in the surface sediments was 0.37±0.24 which larger than the TOC in the Southern Taiwan Strait ,but smaller than the TOC in the center and north of Taiwan Strait in 1980s. High level of TOC content was found near-shore and decreased seaward. Region with high and low value of CaCO3 had the scattering features. The average ratio C/N which indicated the mixed sources of organic materials was 10.12. The background relationship between TOC and TN was close. The power correlation between OC and grain size was suggested that grain size was a limiting factor for TOC. But there was not a good relation between grain size and CaCO3. TOC in sediment was not coupled with primary production in water in or around the upwelling area of the southern Taiwan Straint. After calculation, burial fluxes of carbon was 105 t/a in the sediments of the western Taiwan Strait. The terrestrial input, coastal current and upwelling significantly influenced the burial fluxes of carbon in the sediment.
2011, 33(5): 83-90.
Abstract:
Previous studies show that: the composition and form distribution of lipids vary distinctly in different sediments, so to study the composition and form distribution of lipids biomarkers in southern coastal area of Zhejiang Province (the mud areas of the East China Sea shelf), a sediment core is collected, free and OH--labile lipids of the core are released via sequential treatments. Results show that fatty acids are in obvious even carbon number predominance, and characteristic of single peak with C16-fatty acids as the main peak, the vertical content distribution of fatty acids is mainly controlled by degradation, bound form is the main existent form of fatty acids in the core except in surficial sediment, where fatty acids mainly exist in free forms. A&K (fractions of alcohols and ketones) which are constituted mainly by sterols and fatty alcohols exist as free forms in majority, but phytols perform distinctly which mainly exist in bound forms, degradation mightily affects their vertical content distributions, but for ketones, eutrophication of the upper water in the East China Sea probably also play an important role, and in sediments of about 1950-1969, the contents of many lipids vary abnormally, we consider that this may illuminate the possible change of the ecosystem of upper water in the East China Sea caused by Changjiang River floods in 1954 and 1969. Hydrocarbons are characteristic of double peaks, and the concentration of C29,C31 are higher than other hydrocarbons, hydrocarbons are mainly exist in free forms, and UCM (Unresolved Complex Mixtures) peaks only emerge in chromatograms of free hydrocarbons fractions. Fatty acids and A&K in each form are mainly from marine sources while terrestrial input is the main source of hydrocarbons.
Previous studies show that: the composition and form distribution of lipids vary distinctly in different sediments, so to study the composition and form distribution of lipids biomarkers in southern coastal area of Zhejiang Province (the mud areas of the East China Sea shelf), a sediment core is collected, free and OH--labile lipids of the core are released via sequential treatments. Results show that fatty acids are in obvious even carbon number predominance, and characteristic of single peak with C16-fatty acids as the main peak, the vertical content distribution of fatty acids is mainly controlled by degradation, bound form is the main existent form of fatty acids in the core except in surficial sediment, where fatty acids mainly exist in free forms. A&K (fractions of alcohols and ketones) which are constituted mainly by sterols and fatty alcohols exist as free forms in majority, but phytols perform distinctly which mainly exist in bound forms, degradation mightily affects their vertical content distributions, but for ketones, eutrophication of the upper water in the East China Sea probably also play an important role, and in sediments of about 1950-1969, the contents of many lipids vary abnormally, we consider that this may illuminate the possible change of the ecosystem of upper water in the East China Sea caused by Changjiang River floods in 1954 and 1969. Hydrocarbons are characteristic of double peaks, and the concentration of C29,C31 are higher than other hydrocarbons, hydrocarbons are mainly exist in free forms, and UCM (Unresolved Complex Mixtures) peaks only emerge in chromatograms of free hydrocarbons fractions. Fatty acids and A&K in each form are mainly from marine sources while terrestrial input is the main source of hydrocarbons.
2011, 33(5): 91-96.
Abstract:
The peridotites in landward-slope of Mariana trench regarded as the analogue of ophiolites, record the metasomatism between subducting slab fluid and subarc mantle wedge. Amphiboles is a product of the metasomatism. Our EPMA data suggest that the amphiboles in south Mariana trench inner-slope mainly tremolite and magnesiohornblende with little edenite.Magnesiohornblende have lower Mg# and significantly high Na2O and Al2O3 related to tremolite. The component of amphibole expectially magnesiohornblende suggests the matasomatic fluid contain high Si, Ca, Al, Na but extremely low Ti. The component difference between tremolite and magnesiohornblende might be attributed to fluid origin from difference depth. Fluid from relative shallow may be rich in Si and Ca but dilute Al and Na, and the fluid which formed magnesiohornblende may be origin from deeper slab which release more Al and Na.
The peridotites in landward-slope of Mariana trench regarded as the analogue of ophiolites, record the metasomatism between subducting slab fluid and subarc mantle wedge. Amphiboles is a product of the metasomatism. Our EPMA data suggest that the amphiboles in south Mariana trench inner-slope mainly tremolite and magnesiohornblende with little edenite.Magnesiohornblende have lower Mg# and significantly high Na2O and Al2O3 related to tremolite. The component of amphibole expectially magnesiohornblende suggests the matasomatic fluid contain high Si, Ca, Al, Na but extremely low Ti. The component difference between tremolite and magnesiohornblende might be attributed to fluid origin from difference depth. Fluid from relative shallow may be rich in Si and Ca but dilute Al and Na, and the fluid which formed magnesiohornblende may be origin from deeper slab which release more Al and Na.
2011, 33(5): 97-103.
Abstract:
As a method of inferring net sediment transport pathway from spatial distribution of grain size parameters, the grain size trends analysis (GSTA) has been employed widely in cases of marine geology studies. In this paper, based on the concept of "dynamic populations", a one dimension suspended sediment transport modal has been established to deduce the formation of grain size trend in the net sediment transport direction. The result show that:if the hydrodynamic energy level decreasing along sediment transporting direction, two kinds of grain size trend can form successively in the transporting direction; whereas, if the hydrodynamic energy increasing along sediment transport direction, three kinds of grain size trend can form successively at most. The speed of hydraulic dynamic energy enhancing/attenuation can obviously change the GST distribution along transporting path, Higher speed can enable the GST transform complete in shorter distance. The value of kurtosis has the same variation trend as Std and can be more sensitive to mixing ratio changing, therefore, better result can be gained if we replace the Std with kurtosis in GSTA.
As a method of inferring net sediment transport pathway from spatial distribution of grain size parameters, the grain size trends analysis (GSTA) has been employed widely in cases of marine geology studies. In this paper, based on the concept of "dynamic populations", a one dimension suspended sediment transport modal has been established to deduce the formation of grain size trend in the net sediment transport direction. The result show that:if the hydrodynamic energy level decreasing along sediment transporting direction, two kinds of grain size trend can form successively in the transporting direction; whereas, if the hydrodynamic energy increasing along sediment transport direction, three kinds of grain size trend can form successively at most. The speed of hydraulic dynamic energy enhancing/attenuation can obviously change the GST distribution along transporting path, Higher speed can enable the GST transform complete in shorter distance. The value of kurtosis has the same variation trend as Std and can be more sensitive to mixing ratio changing, therefore, better result can be gained if we replace the Std with kurtosis in GSTA.
Analysis of the characteristics of whales mitochondrial genomes and exploration of molecular markers
2011, 33(5): 104-114.
Abstract:
The basic characteristics (including protein coding genes, selection pressure and different loci etc.) of whales mitochondrial genomes were fully revealed by comprehensive analysis of 32 whales mitochondrial genomes. Whales mitochondrial genomes contain 37 standard metazoan genes and their gene order is identical.. The Ka/Ks ratio of the whales (Eubalaena, Balaenoptera, Stenella and Tursiops) 13 mitochondrial protein coding genes is lower than 1 (range between 0 and 0.587 7), indicating for the purifying selection (negative selection). The average Ka/Ks of cox3 gene is the lowest, followed by cox1 , cox2 and cob genes, indicating that these genes bear a strong selection pressure and functional constraints. Meanwhile, the average Ka/Ks of nad6 gene is the highest, followed by atp8 , nad2 and atp6 gene, indicating these genes bear weaker selection pressure. The genetic variation analysis of main genes (13 protein coding genes and 2 ribosomal RNA genes) and D-loop region within 32 species and intra-genus (Eubalaena, Balaenoptera, Stenella and Tursiops) showed that nad5 , nad4 and nad2 gene are ideal molecular markers and can be used as supplementary molecular markers to cox1 gene, which providing a reference for the conservation of whales biological diversity and use of the biological resources rationally.
The basic characteristics (including protein coding genes, selection pressure and different loci etc.) of whales mitochondrial genomes were fully revealed by comprehensive analysis of 32 whales mitochondrial genomes. Whales mitochondrial genomes contain 37 standard metazoan genes and their gene order is identical.. The Ka/Ks ratio of the whales (Eubalaena, Balaenoptera, Stenella and Tursiops) 13 mitochondrial protein coding genes is lower than 1 (range between 0 and 0.587 7), indicating for the purifying selection (negative selection). The average Ka/Ks of cox3 gene is the lowest, followed by cox1 , cox2 and cob genes, indicating that these genes bear a strong selection pressure and functional constraints. Meanwhile, the average Ka/Ks of nad6 gene is the highest, followed by atp8 , nad2 and atp6 gene, indicating these genes bear weaker selection pressure. The genetic variation analysis of main genes (13 protein coding genes and 2 ribosomal RNA genes) and D-loop region within 32 species and intra-genus (Eubalaena, Balaenoptera, Stenella and Tursiops) showed that nad5 , nad4 and nad2 gene are ideal molecular markers and can be used as supplementary molecular markers to cox1 gene, which providing a reference for the conservation of whales biological diversity and use of the biological resources rationally.
2011, 33(5): 115-123.
Abstract:
Oplegnathus fasciatus and O. punctatus, belonging to the family Oplegnathidae, are commercially important fisheries resources in China. To date, no researches have been carried out on the relationship between O. fasciatus and O. punctatus by mitochondrial DNA sequences characteristics. Partial nucleotide sequences of mitochondrial DNA COI gene, Cyt b gene and D-loop fragment were sequenced and analyzed to estimate the degree of genetic differentiation between O. fasciatus and O. punctatus. One hundred and three nucleotide substitutions were checked in the total 1 107 bp sequences analyzed, and most of them were synonymous transitions at the third codon positions in the two protein-coding genes. Nucleotide composition analysis indicated a strong bias against guanine (G) in the three fragments, especially in the third codon positions of COI and Cyt b genes. The mean genetic distances based on the COI, Cyt b and D-loop fragments between O. fasciatus and O. punctatus were 0.097, 0.080 and 0.172, respectively. The average genetic distances showed interspecific differentiation within genus. There were obvious differences in the rates of nucleotide substitution between the two species in the three mtDNA segments. In contrast with previous research, the rate of nucleotide substitution for COI gene fragment was higher than that of Cyt b fragment in the present study. The estimated divergence time between O. fasciatus and O. punctatus based on Cyt b and ND5 genes was about 3.85~5.3 million years ago, which indicated a Early Pliocene divergence of the two species.
Oplegnathus fasciatus and O. punctatus, belonging to the family Oplegnathidae, are commercially important fisheries resources in China. To date, no researches have been carried out on the relationship between O. fasciatus and O. punctatus by mitochondrial DNA sequences characteristics. Partial nucleotide sequences of mitochondrial DNA COI gene, Cyt b gene and D-loop fragment were sequenced and analyzed to estimate the degree of genetic differentiation between O. fasciatus and O. punctatus. One hundred and three nucleotide substitutions were checked in the total 1 107 bp sequences analyzed, and most of them were synonymous transitions at the third codon positions in the two protein-coding genes. Nucleotide composition analysis indicated a strong bias against guanine (G) in the three fragments, especially in the third codon positions of COI and Cyt b genes. The mean genetic distances based on the COI, Cyt b and D-loop fragments between O. fasciatus and O. punctatus were 0.097, 0.080 and 0.172, respectively. The average genetic distances showed interspecific differentiation within genus. There were obvious differences in the rates of nucleotide substitution between the two species in the three mtDNA segments. In contrast with previous research, the rate of nucleotide substitution for COI gene fragment was higher than that of Cyt b fragment in the present study. The estimated divergence time between O. fasciatus and O. punctatus based on Cyt b and ND5 genes was about 3.85~5.3 million years ago, which indicated a Early Pliocene divergence of the two species.
2011, 33(5): 124-132.
Abstract:
The partial sequences of mitochondrial 16S rRNA gene of Helice tientsinensis (six populations), H. latimera (four populations), Helicana wuana (two populations) and H. japonica(one population) from the coast of China were determined and subjected to phylogenetic analysis with the inclusion of other species of Helice and Helicana obtained from the GenBank. The length of sequence of Helice tientsinensis and H. latimera was 525 bp, excluding 526 bp of two individuals from Dandong population of H. tientsinensis. Five haplotypes were found in them. The lengths of sequence of Helicana wuana and H. japonica were 525bp and 523bp respectively. There were no differences of sequence among individuals within populations of them, except Rizhao and Dandong populations. The A, T, G and C contents of them were similar, and the AT content(72.3%~73.7%)was higher than GC content. The resultant sequences of H. tientsinensis, H. latimera, H. wuana and H. japonica were 526bp long with 4 indels, of which 36 sites were variable and 26 sites were parsimoniously informative, and average transition/transversion ratio was 2.8. Among the five haplotypes, six individuals of H. latimera from Quanzhou and Ningbo populations and four individuals of H. tientsinensis from Ningbo and Rizhao populations shared one haplotype, and genetic distances among them were very small(0.19%~1.15%), implying that they may represent different morphotypes of the same species. Molecular phylogenetic trees indicated that the genera Helice and Helicana were monophyletic respectively, the large net genetic distances between them supported that they were updated from subgenus to genus. The molecular data also supported that the Pseudohelice and Parahelice were updated from subgenus to genus, and Helice/Chasmagnathus complex was divided into seven genera by morphology.
The partial sequences of mitochondrial 16S rRNA gene of Helice tientsinensis (six populations), H. latimera (four populations), Helicana wuana (two populations) and H. japonica(one population) from the coast of China were determined and subjected to phylogenetic analysis with the inclusion of other species of Helice and Helicana obtained from the GenBank. The length of sequence of Helice tientsinensis and H. latimera was 525 bp, excluding 526 bp of two individuals from Dandong population of H. tientsinensis. Five haplotypes were found in them. The lengths of sequence of Helicana wuana and H. japonica were 525bp and 523bp respectively. There were no differences of sequence among individuals within populations of them, except Rizhao and Dandong populations. The A, T, G and C contents of them were similar, and the AT content(72.3%~73.7%)was higher than GC content. The resultant sequences of H. tientsinensis, H. latimera, H. wuana and H. japonica were 526bp long with 4 indels, of which 36 sites were variable and 26 sites were parsimoniously informative, and average transition/transversion ratio was 2.8. Among the five haplotypes, six individuals of H. latimera from Quanzhou and Ningbo populations and four individuals of H. tientsinensis from Ningbo and Rizhao populations shared one haplotype, and genetic distances among them were very small(0.19%~1.15%), implying that they may represent different morphotypes of the same species. Molecular phylogenetic trees indicated that the genera Helice and Helicana were monophyletic respectively, the large net genetic distances between them supported that they were updated from subgenus to genus. The molecular data also supported that the Pseudohelice and Parahelice were updated from subgenus to genus, and Helice/Chasmagnathus complex was divided into seven genera by morphology.
2011, 33(5): 133-138.
Abstract:
Molecular phylogenetic tree analysis on a thermostable amypopullulanase in an Archaeaon strain Thermococcus siculi HJ21 isolated from a deep-sea hydrothermal vents was performed based on experimental enzymatic analysis and amino acid squences of amylopullulanases deposited in GenBank. The N-terminal catalytic region of the amylopullulanase was heterologously expressed in E. coli through pMal-c2x expression system, resulting a fusion protein in which there is a maltose binding protein fused to the N-terminus of the N-terminal catalytic region of the amylopullulanase. Alpha-amylase and pullulanase activities of the fusion protein were experimentally analyzed. The optimal temperatures of the two activities were both at 100 ℃. The optimal pHs of amylase and pullulanase activities were at 5 and 6 respectively. The specific activities of the amylase and pullulanase activities were 6.5 and 11.5 U/mg respectively. The results showed that α-amylase activity was lower than pullulanase activity and the C-terminal region of the thermostable amylopullulanase was non-necessary for the enzymatic activities. The thermostable amylopullulanase fusion protein obtained in this study could be further used for combination with thermostable amylases in the sugar industry.
Molecular phylogenetic tree analysis on a thermostable amypopullulanase in an Archaeaon strain Thermococcus siculi HJ21 isolated from a deep-sea hydrothermal vents was performed based on experimental enzymatic analysis and amino acid squences of amylopullulanases deposited in GenBank. The N-terminal catalytic region of the amylopullulanase was heterologously expressed in E. coli through pMal-c2x expression system, resulting a fusion protein in which there is a maltose binding protein fused to the N-terminus of the N-terminal catalytic region of the amylopullulanase. Alpha-amylase and pullulanase activities of the fusion protein were experimentally analyzed. The optimal temperatures of the two activities were both at 100 ℃. The optimal pHs of amylase and pullulanase activities were at 5 and 6 respectively. The specific activities of the amylase and pullulanase activities were 6.5 and 11.5 U/mg respectively. The results showed that α-amylase activity was lower than pullulanase activity and the C-terminal region of the thermostable amylopullulanase was non-necessary for the enzymatic activities. The thermostable amylopullulanase fusion protein obtained in this study could be further used for combination with thermostable amylases in the sugar industry.
2011, 33(5): 139-145.
Abstract:
Diatom analysis of samples from sediment traps deployed in the northern and central South China Sea reveals the seasonal changes of diatom fluxes and their relationships with the East Asia monsoon system. It is shown that the diatom flux can be treated as an indicator of marine primary productivity in the northern and central South China Sea. Especial low diatom fluxes are found in the northern South China Sea, which might be related to the El ni o event during 1987-1988. In the northern South China Sea, apparent increased diatom fluxes are found during the winter monsoon period, which is correlated with stronger sea water vertical mixing and higher aeolian particles input during this period. Relatively high fluxes are also found in the deep water than in the shallow water, indicating possible deep sea lateral advection in the northern South China Sea. Higher diatom fluxes during the summer monsoon period with peak flux in late June to early July are revealed in the central South China Sea, which may be stimulated by higher nutrient input during the summer monsoon.
Diatom analysis of samples from sediment traps deployed in the northern and central South China Sea reveals the seasonal changes of diatom fluxes and their relationships with the East Asia monsoon system. It is shown that the diatom flux can be treated as an indicator of marine primary productivity in the northern and central South China Sea. Especial low diatom fluxes are found in the northern South China Sea, which might be related to the El ni o event during 1987-1988. In the northern South China Sea, apparent increased diatom fluxes are found during the winter monsoon period, which is correlated with stronger sea water vertical mixing and higher aeolian particles input during this period. Relatively high fluxes are also found in the deep water than in the shallow water, indicating possible deep sea lateral advection in the northern South China Sea. Higher diatom fluxes during the summer monsoon period with peak flux in late June to early July are revealed in the central South China Sea, which may be stimulated by higher nutrient input during the summer monsoon.
2011, 33(5): 146-151.
Abstract:
The photosynthetic carbon fixation of phytoplankton was affected significantly by solar UV radiation, while these effects are wavelength dependent.We investigated the photosynthetic carbon fixation by surface water phytoplankton assemblages of the South China Sea in summer under different radiation treatments to evaluate the photosynthetic response to different wavelength of UVR.The photosynthetic carbon fixation rate was the highest under PAR treatment, with the mean value of 10.86 μg/(μg·h).When the samples were exposed to PAR+UV radiation, the photosynthetic carbon fixation rate decreased significantly, the shorter wavelength exposed, the lower photosynthetic carbon fixation rate observed.As a result, the photosynthetic carbon fixation rate under full spectrum of solar radiation was the lowest, with the mean value of 6.51 μg/(μg·h), the relative inhibition induced by UVR was about 40%.Moreover, the effects of UV radiation were wavelength dependent, biological weighting function (BWF) indicated that the shorter wavelength of UVR, the higher inhibition per energy induced.The biological weight of the shortest wavelength of UV-B (i.e.280 nm) was at least 106 times of the UV-A (＞320 nm).
The photosynthetic carbon fixation of phytoplankton was affected significantly by solar UV radiation, while these effects are wavelength dependent.We investigated the photosynthetic carbon fixation by surface water phytoplankton assemblages of the South China Sea in summer under different radiation treatments to evaluate the photosynthetic response to different wavelength of UVR.The photosynthetic carbon fixation rate was the highest under PAR treatment, with the mean value of 10.86 μg/(μg·h).When the samples were exposed to PAR+UV radiation, the photosynthetic carbon fixation rate decreased significantly, the shorter wavelength exposed, the lower photosynthetic carbon fixation rate observed.As a result, the photosynthetic carbon fixation rate under full spectrum of solar radiation was the lowest, with the mean value of 6.51 μg/(μg·h), the relative inhibition induced by UVR was about 40%.Moreover, the effects of UV radiation were wavelength dependent, biological weighting function (BWF) indicated that the shorter wavelength of UVR, the higher inhibition per energy induced.The biological weight of the shortest wavelength of UV-B (i.e.280 nm) was at least 106 times of the UV-A (＞320 nm).
2011, 33(5): 152-162.
Abstract:
The sediment movement characteristics of silt-sandy beach are studied systematically. The following five aspects are instructed: (1) definition of silt-sandy beach, (2) the basic hydraulic characteristics of sediment, (3) the patterns of sediment movement, (4) the statistical characteristics of sudden siltation in the channel, (5) the siltation calculation of channel. It is provided that the median size of sediment, the silt percentage and the sorting coefficient should be considered in definition of silt-sandy beach. The sand on the silt-sandy beach moves actively, the threshold velocity is small and the settling velocity is large. Because three movement patterns that are suspended sediment, near-bed water layer of high sediment concentration and bed load coexist on silt-sandy beach,the three-layer mode for siltation calculation of channel is put forward. The relation of sudden siltation and effective wind energy is built and the probability statistical method of sudden siltation is advanced.
The sediment movement characteristics of silt-sandy beach are studied systematically. The following five aspects are instructed: (1) definition of silt-sandy beach, (2) the basic hydraulic characteristics of sediment, (3) the patterns of sediment movement, (4) the statistical characteristics of sudden siltation in the channel, (5) the siltation calculation of channel. It is provided that the median size of sediment, the silt percentage and the sorting coefficient should be considered in definition of silt-sandy beach. The sand on the silt-sandy beach moves actively, the threshold velocity is small and the settling velocity is large. Because three movement patterns that are suspended sediment, near-bed water layer of high sediment concentration and bed load coexist on silt-sandy beach,the three-layer mode for siltation calculation of channel is put forward. The relation of sudden siltation and effective wind energy is built and the probability statistical method of sudden siltation is advanced.
2011, 33(5): 163-168.
Abstract:
2011, 33(5): 169-176.
Abstract:
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