2014 Vol. 36, No. 2
Display Method:
2014, 36(2): .
Abstract:
2014, 36(2): 1-15.
Abstract:
A global prognostic model based on Mom4p1,which is a primitive equation nonBoussinesq numerical model,has been integrated 1 400 years from the state of rest based on the realistic topography to study the long term pattern of combined wind-driven and thermodynamically-driven general circulation.The model is driven by monthly climatological mean forces and includes 192×189 horizontal grids and 31 pressure based vertical levels.The main objective is to investigate the mass and heat transports at interbasin passagesand their compensations and roles in the global ocean circulation under equilibrium state of long term spin up.The kinetic energy analysis divides the spin up process into three stages:the quasi-stable state of wind driven current,the growing phase of thermodynamical circulation and the equilibrium state of thermohaline circulation. It is essential to spin up over a thousand years in order to reach the thermohaline equilibrium state from a state of rest. The Arctic Throughflow from the Bering Strait to the Greenland Sea and the Indonesian Throughflow(ITF) are captured and examined with their compensations and existing data. Analysis reveals that the slope structures of sea surface height are the dynamical driving mechanism of the Pacific-Arctic-Atlantic throughflow and ITF. The analysis denotes,in spite of 1.4×106 m3/s of the southward volume transport in the northern Atlantic,there is still 1×1015W of heat transported northward since the northward currents in upper layer carry much higher temperature water than the southward flowing northern Atlantic deep water(NADW).Meridional volume and heat transports are focused on the contributions to NADW renewals and Atlantic meridional overturning circulation(AMOC). Quantitative descriptions of the interbasin exchanges are explained by meridional compensations and supported by previous observations and numerical modeling results. Analysis indicates that the volume and heat exchanges on the interbasin passages proposed in this article manifest their hub roles in the Great Ocean Conveyor system.
A global prognostic model based on Mom4p1,which is a primitive equation nonBoussinesq numerical model,has been integrated 1 400 years from the state of rest based on the realistic topography to study the long term pattern of combined wind-driven and thermodynamically-driven general circulation.The model is driven by monthly climatological mean forces and includes 192×189 horizontal grids and 31 pressure based vertical levels.The main objective is to investigate the mass and heat transports at interbasin passagesand their compensations and roles in the global ocean circulation under equilibrium state of long term spin up.The kinetic energy analysis divides the spin up process into three stages:the quasi-stable state of wind driven current,the growing phase of thermodynamical circulation and the equilibrium state of thermohaline circulation. It is essential to spin up over a thousand years in order to reach the thermohaline equilibrium state from a state of rest. The Arctic Throughflow from the Bering Strait to the Greenland Sea and the Indonesian Throughflow(ITF) are captured and examined with their compensations and existing data. Analysis reveals that the slope structures of sea surface height are the dynamical driving mechanism of the Pacific-Arctic-Atlantic throughflow and ITF. The analysis denotes,in spite of 1.4×106 m3/s of the southward volume transport in the northern Atlantic,there is still 1×1015W of heat transported northward since the northward currents in upper layer carry much higher temperature water than the southward flowing northern Atlantic deep water(NADW).Meridional volume and heat transports are focused on the contributions to NADW renewals and Atlantic meridional overturning circulation(AMOC). Quantitative descriptions of the interbasin exchanges are explained by meridional compensations and supported by previous observations and numerical modeling results. Analysis indicates that the volume and heat exchanges on the interbasin passages proposed in this article manifest their hub roles in the Great Ocean Conveyor system.
2014, 36(2): 16-22.
Abstract:
The isotopic composition of suspended particulate matters (δ15Np) in surface water was studied during February, May, August and November of 2010 in the Changjiang River estuary. Based on the variations of δ15Np in different seasons and regions, the biogeochemical processing of nitrogen transformation was studied and its environmental implications were also revealed. The results showed that δ15Np of SPM was in a wide range of -1.1‰-8.6‰, varying with seasons and geographic regions, which reflected influences of riverine input and biogeochemical processes. In February, the variation of δ15Np reflected the mixing between riverine and marine nitrogen; in May and November, δ15Np decreased with increased Chl a in the surface waters, which indicated assimilation; in August and November, significant positive relationships were found between δ15Np and DIN, which indicated remineralizaion and nitrification.
The isotopic composition of suspended particulate matters (δ15Np) in surface water was studied during February, May, August and November of 2010 in the Changjiang River estuary. Based on the variations of δ15Np in different seasons and regions, the biogeochemical processing of nitrogen transformation was studied and its environmental implications were also revealed. The results showed that δ15Np of SPM was in a wide range of -1.1‰-8.6‰, varying with seasons and geographic regions, which reflected influences of riverine input and biogeochemical processes. In February, the variation of δ15Np reflected the mixing between riverine and marine nitrogen; in May and November, δ15Np decreased with increased Chl a in the surface waters, which indicated assimilation; in August and November, significant positive relationships were found between δ15Np and DIN, which indicated remineralizaion and nitrification.
2014, 36(2): 23-32.
Abstract:
River dominated ocean margins (RiOMars) are the major depocenter of terrestrial organic carbon and are recognized as the most important zone for land-sea interactions, and play a very important role in global biogeochemical cycle of carbon. Effective remineralization of sedimentary organic carbon (SOC) occurs in these systems instead of efficient preservation and burial due to frequent physical and/or biological reworking of sediments in upper layer. In this paper, we introduced two kinds of commonly used methods for the determination of remineralization rate of SOC based on the consumption of O2 and production of CO2, respectively. Advantages, disadvantages and applicability of these methods were analyzed. In order to obtain a better understanding of the remineralization of SOC and its impact on carbon sink in continental margins, major processes and characteristics of the remineralization of SOC in RiOMars were summarized into several aspects including transformation of carbon forms, homogeneous vertical distribution of surface sediments, suboxic redox properties, low preservation of organic carbon, occurrence of "reverse weathering" and high microbial biomass.
River dominated ocean margins (RiOMars) are the major depocenter of terrestrial organic carbon and are recognized as the most important zone for land-sea interactions, and play a very important role in global biogeochemical cycle of carbon. Effective remineralization of sedimentary organic carbon (SOC) occurs in these systems instead of efficient preservation and burial due to frequent physical and/or biological reworking of sediments in upper layer. In this paper, we introduced two kinds of commonly used methods for the determination of remineralization rate of SOC based on the consumption of O2 and production of CO2, respectively. Advantages, disadvantages and applicability of these methods were analyzed. In order to obtain a better understanding of the remineralization of SOC and its impact on carbon sink in continental margins, major processes and characteristics of the remineralization of SOC in RiOMars were summarized into several aspects including transformation of carbon forms, homogeneous vertical distribution of surface sediments, suboxic redox properties, low preservation of organic carbon, occurrence of "reverse weathering" and high microbial biomass.
2014, 36(2): 33-39.
Abstract:
Barium cycling in deep-sea sediments,especially those of the areas where gas hydrate occurs,is controlled by redox between sulfate and methane within a sediment-interstitial water system. "Barium fronts" occurring in deep-sea sediments,therefore,are generally related to decomposition of gas hydrate. 4 "Barium fronts" were recognised from sediments of upper section (0-185 m). Each of them exactly corresponded to sulfate-methane interface,decrease in chlorin flux and glacial-interglacial transition,indicating that during glacial ages,gas hydrate in shallow regions,such as Dongsha Archipelago seabed would decompose due to decease in sea level stands,releasing fluids lower salinity and higher methane concentration. Some of the released fluid would laterally migrate into ODP1146 site,resulting in sulfate depletion to zero and excess barium accumulation to maximum at glacial terminations; meanwhile,some of the released fluid would migrate into air,accelerating glacial age end due to greenhouse effect of methane. Impacted by glacial-interglacial cycles over the past 500 ka,the fluids with lower salinity and higher methane,released by decomposition of gas hydrate from shallow areas,such as Dongsha archipelago,would vary in oscillatory way,resulting in burying of multiple "barium fronts" in sediments. The "barium fronts" can be used as a proxy for assesment of variation in methane flux released by decomposition of gas hydrate.
Barium cycling in deep-sea sediments,especially those of the areas where gas hydrate occurs,is controlled by redox between sulfate and methane within a sediment-interstitial water system. "Barium fronts" occurring in deep-sea sediments,therefore,are generally related to decomposition of gas hydrate. 4 "Barium fronts" were recognised from sediments of upper section (0-185 m). Each of them exactly corresponded to sulfate-methane interface,decrease in chlorin flux and glacial-interglacial transition,indicating that during glacial ages,gas hydrate in shallow regions,such as Dongsha Archipelago seabed would decompose due to decease in sea level stands,releasing fluids lower salinity and higher methane concentration. Some of the released fluid would laterally migrate into ODP1146 site,resulting in sulfate depletion to zero and excess barium accumulation to maximum at glacial terminations; meanwhile,some of the released fluid would migrate into air,accelerating glacial age end due to greenhouse effect of methane. Impacted by glacial-interglacial cycles over the past 500 ka,the fluids with lower salinity and higher methane,released by decomposition of gas hydrate from shallow areas,such as Dongsha archipelago,would vary in oscillatory way,resulting in burying of multiple "barium fronts" in sediments. The "barium fronts" can be used as a proxy for assesment of variation in methane flux released by decomposition of gas hydrate.
2014, 36(2): 40-50.
Abstract:
The reconstruction of paleoproductivity at home and abroad has been a hot spot in the research of marine ecology since the 1980s. However, most of the studies are in abyssal regions. Continental shelf areas are influenced more obviously by the terrigenous matter and more difficult to be studied than abyssal regions. It makes use of carbon stable isotope compositions in organic matter of modern sediments to estimate the sea-derived carbon contents. Based on this, combining the investigation data of the several representative indicators of the primary productivity in surface sediments (phytoplankton biomass, chlorophyll-a concentration, as well as the diatom content), to seek correlation between the sea-derived carbon content and the productivity index in cores. Then, the high resolution of the paleoproductivity records over 200 a can be reconstructed from the sea-derived carbon content in 3 typical columnar sediments from the southern Huanghai Sea cold eddy zone. It has important significance for studying the evolution rule of ecological environment in the continental shelf area. Controlling factors on the primary productivity evolution reconstructed for the southern Yellow Sea are discussed elementarily, it shows that the primary productivity wave elevation over 200 a is consistent with sea surface temperature trends, but its main control factor still is nutrient supply, in which land nutrients and pollutants play an important role.
The reconstruction of paleoproductivity at home and abroad has been a hot spot in the research of marine ecology since the 1980s. However, most of the studies are in abyssal regions. Continental shelf areas are influenced more obviously by the terrigenous matter and more difficult to be studied than abyssal regions. It makes use of carbon stable isotope compositions in organic matter of modern sediments to estimate the sea-derived carbon contents. Based on this, combining the investigation data of the several representative indicators of the primary productivity in surface sediments (phytoplankton biomass, chlorophyll-a concentration, as well as the diatom content), to seek correlation between the sea-derived carbon content and the productivity index in cores. Then, the high resolution of the paleoproductivity records over 200 a can be reconstructed from the sea-derived carbon content in 3 typical columnar sediments from the southern Huanghai Sea cold eddy zone. It has important significance for studying the evolution rule of ecological environment in the continental shelf area. Controlling factors on the primary productivity evolution reconstructed for the southern Yellow Sea are discussed elementarily, it shows that the primary productivity wave elevation over 200 a is consistent with sea surface temperature trends, but its main control factor still is nutrient supply, in which land nutrients and pollutants play an important role.
2014, 36(2): 51-65.
Abstract:
Seven sections are studied in Yuedong(eastern Guangdong Province, China) upwelling area and the shelf-slope area of the northern South China Sea(NSCS). By analyzing the temperature, salinity, density, turbidity and chlorophyll concentration of seawater, and the mean grain size, volume concentration of suspended particles, the characteristics of the marine nepheloid layers in the NSCS and their influential factors are studied. The results show that the bottom nepheloid layer(BNL) develops widely in Yuedong upwelling area, and the surface nepheloid layer(SNL) exists at few sites. Particle matter in nepheloid layer is mainly from high energy coastal processes and bays, rivers in Guangdong Province.The BNL also develops widely in the shelf-slope area of the NSCS; the SNL often exists in the inner shelf off the Zhujiang River Estuary and the outer shelf-slope area; the intermediate nepheloid layer develops in the slope area. Particle matter in the nepheloid layer is mainly from the Zhujiang River and rivers in southwest Taiwan Island, seabed sediments and biogenous particle matter. The intensity and thickness of the BNL are mainly controlled by hydrodynamic conditions, dispersion of matter by river discharge, resuspension of fine deposites and so on.
Seven sections are studied in Yuedong(eastern Guangdong Province, China) upwelling area and the shelf-slope area of the northern South China Sea(NSCS). By analyzing the temperature, salinity, density, turbidity and chlorophyll concentration of seawater, and the mean grain size, volume concentration of suspended particles, the characteristics of the marine nepheloid layers in the NSCS and their influential factors are studied. The results show that the bottom nepheloid layer(BNL) develops widely in Yuedong upwelling area, and the surface nepheloid layer(SNL) exists at few sites. Particle matter in nepheloid layer is mainly from high energy coastal processes and bays, rivers in Guangdong Province.The BNL also develops widely in the shelf-slope area of the NSCS; the SNL often exists in the inner shelf off the Zhujiang River Estuary and the outer shelf-slope area; the intermediate nepheloid layer develops in the slope area. Particle matter in the nepheloid layer is mainly from the Zhujiang River and rivers in southwest Taiwan Island, seabed sediments and biogenous particle matter. The intensity and thickness of the BNL are mainly controlled by hydrodynamic conditions, dispersion of matter by river discharge, resuspension of fine deposites and so on.
2014, 36(2): 66-74.
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In the present paper, we investigated the detrital mineral composition, assemblage and distribution in surface sediments from Liaodong Bay (LDB), Bohai Sea. The log-ratio method was used to represent mineral compositional data for the multiple statistical analysis. Heavy mineral weight percentage is 6.3% on average, and the high value areas are located at Liuguhe river mouth and nearshore zone of northwestern coast. A total of 7 species of light mineral and 38 species of heavy minerals were identified by using the classical microscopic method. Light minerals are dominated in quartz, plagioclase and K-feldspar; whilst heavy minerals are mainly composed of hornblende, epidote, magnetite, garnet, ilmenite, titanite, actinolite, limonite, hematite, apatite and augite. The LDB could be divided into 2 detrital mineral provinces, including 6 sub-provinces, according to the detrital mineral assemblages and their distribution pattern. Sediments in Liuguhe river mouth and nearshore zone of northwestern coast are mainly derived from Liuguhe river, small streams flowing into the northwestern LDB and coastal erosion; sediments in northern LDB are mainly originated from Shuangtaizihe river and Daliaohe river; central LDB province is a multi-source depositional area; sediments in southern LDB are mainly affected by adjacent sea and Fuzhouhe river; sediments in Liaodong Shoal province, which is located in southeastern LDB, may be dramatically reformed by tidal current. Compared to sediments from rivers around LDB, quartz/feldspar ratio and ZTR index of surface sediments show an increasing trend. Assemblages and distribution pattern of detrital minerals in the bay are mainly controlled by provenances, and also affected by hydrodynamic and grain density.
In the present paper, we investigated the detrital mineral composition, assemblage and distribution in surface sediments from Liaodong Bay (LDB), Bohai Sea. The log-ratio method was used to represent mineral compositional data for the multiple statistical analysis. Heavy mineral weight percentage is 6.3% on average, and the high value areas are located at Liuguhe river mouth and nearshore zone of northwestern coast. A total of 7 species of light mineral and 38 species of heavy minerals were identified by using the classical microscopic method. Light minerals are dominated in quartz, plagioclase and K-feldspar; whilst heavy minerals are mainly composed of hornblende, epidote, magnetite, garnet, ilmenite, titanite, actinolite, limonite, hematite, apatite and augite. The LDB could be divided into 2 detrital mineral provinces, including 6 sub-provinces, according to the detrital mineral assemblages and their distribution pattern. Sediments in Liuguhe river mouth and nearshore zone of northwestern coast are mainly derived from Liuguhe river, small streams flowing into the northwestern LDB and coastal erosion; sediments in northern LDB are mainly originated from Shuangtaizihe river and Daliaohe river; central LDB province is a multi-source depositional area; sediments in southern LDB are mainly affected by adjacent sea and Fuzhouhe river; sediments in Liaodong Shoal province, which is located in southeastern LDB, may be dramatically reformed by tidal current. Compared to sediments from rivers around LDB, quartz/feldspar ratio and ZTR index of surface sediments show an increasing trend. Assemblages and distribution pattern of detrital minerals in the bay are mainly controlled by provenances, and also affected by hydrodynamic and grain density.
2014, 36(2): 75-80.
Abstract:
A long-term morphodynamic model is used to simulate the evolution course of the Modaomen Estuary between 1964 and 1977, by choosing representative condition.The results of the numerical simulation show that Hezhou to Jiaobeisha shallow bank and Shanggou have been fast-filling-up, the deposition thicknesses of the two areas both exceed 40 cm in 13 years. By contrast with the banks, the Mangzhou to Dajingjiao part of Hengzhou Trough and the east-trough of "shanggou" are eroded and enlarged. The evolvement courses of the rainy season and dry season are ultimately different. In the rainy season, banks are filled up and troughs are eroded, but in the dry season banks and troughs are both filled up. In the process of evolution, various rocky islands make the evolution course pluralistic, and human activities have played import roles in the evolution of Modaomen estuary.
A long-term morphodynamic model is used to simulate the evolution course of the Modaomen Estuary between 1964 and 1977, by choosing representative condition.The results of the numerical simulation show that Hezhou to Jiaobeisha shallow bank and Shanggou have been fast-filling-up, the deposition thicknesses of the two areas both exceed 40 cm in 13 years. By contrast with the banks, the Mangzhou to Dajingjiao part of Hengzhou Trough and the east-trough of "shanggou" are eroded and enlarged. The evolvement courses of the rainy season and dry season are ultimately different. In the rainy season, banks are filled up and troughs are eroded, but in the dry season banks and troughs are both filled up. In the process of evolution, various rocky islands make the evolution course pluralistic, and human activities have played import roles in the evolution of Modaomen estuary.
2014, 36(2): 81-92.
Abstract:
In order to analysis the current characteristics and temporal variations of fish community structure of the Changjiang River estuary, fishes were collected every month from May 2010 to April 2011, using set nets. During the study time, 56 fish species were sampled, Perciformes (27 taxa) and Clupeiformes (10 species) were the two most abundant orders. Among the total 56 species, 26 demersal species, 21 pelagic species and 9 benthic species were caught. Fish faunas showed typical subtropical features, thus 25 tropical species and 31 warm-water taxa were found respectively. Both abundances and biomass were dominated by a few species. In terms of fish ecological guild, numbers of species were mainly represented by marine migrants and estuarine species, while marine migrants were the most important guild whether in abundance or biomass. Mean fish species richness was lowest and highest recorded in January 2011 (7.2 species) and July (18.3 taxa), respectively. Total abundance had a minimum in January 2011 (71 individuals per net) and a maximum during November 2010 (2 272 individuals per net). Fish biomass, got reached minimum values in September (11 892 g per net), and maximum during January 2011 (351 g per net). Temporal variations in abundances of the most abundant species varied may be related to reduce the competition behaviour. Average Shannon-Wiener and Pielou indexes, using abundance data, reached maximum in July 2010 (2.69) and August (0.77), respectively, and both minimum June (1.44 and 0.44, respectively). Non-metric multidimensional scaling, NMDS showed that community structures in two continued months were similar, however, that in December 2010 differs from that in January 2011, the method also illustrated a clear division into four distinct groups of samples (GroupⅠ: samples capturing from January 2011 to April 2011; GroupⅡ: samples capturing from May 2010 to the first half month of August 2010; Group Ⅲ: samples capturing from the second half month of November 2010 to December 2010; Group Ⅳ: samples sampling between the second half month of August 2010 and the first half month of November 2010). Additionally, multi regression model demonstrated that among the three variables (temperature, salinity and inflow) examined, temperature was the most important variable influencing the abundance across the study period. Due to the increasing fishing pressure on fish community of the Yangtze River estuary, one measure for management is to reduce the high fishing effort.
In order to analysis the current characteristics and temporal variations of fish community structure of the Changjiang River estuary, fishes were collected every month from May 2010 to April 2011, using set nets. During the study time, 56 fish species were sampled, Perciformes (27 taxa) and Clupeiformes (10 species) were the two most abundant orders. Among the total 56 species, 26 demersal species, 21 pelagic species and 9 benthic species were caught. Fish faunas showed typical subtropical features, thus 25 tropical species and 31 warm-water taxa were found respectively. Both abundances and biomass were dominated by a few species. In terms of fish ecological guild, numbers of species were mainly represented by marine migrants and estuarine species, while marine migrants were the most important guild whether in abundance or biomass. Mean fish species richness was lowest and highest recorded in January 2011 (7.2 species) and July (18.3 taxa), respectively. Total abundance had a minimum in January 2011 (71 individuals per net) and a maximum during November 2010 (2 272 individuals per net). Fish biomass, got reached minimum values in September (11 892 g per net), and maximum during January 2011 (351 g per net). Temporal variations in abundances of the most abundant species varied may be related to reduce the competition behaviour. Average Shannon-Wiener and Pielou indexes, using abundance data, reached maximum in July 2010 (2.69) and August (0.77), respectively, and both minimum June (1.44 and 0.44, respectively). Non-metric multidimensional scaling, NMDS showed that community structures in two continued months were similar, however, that in December 2010 differs from that in January 2011, the method also illustrated a clear division into four distinct groups of samples (GroupⅠ: samples capturing from January 2011 to April 2011; GroupⅡ: samples capturing from May 2010 to the first half month of August 2010; Group Ⅲ: samples capturing from the second half month of November 2010 to December 2010; Group Ⅳ: samples sampling between the second half month of August 2010 and the first half month of November 2010). Additionally, multi regression model demonstrated that among the three variables (temperature, salinity and inflow) examined, temperature was the most important variable influencing the abundance across the study period. Due to the increasing fishing pressure on fish community of the Yangtze River estuary, one measure for management is to reduce the high fishing effort.
2014, 36(2): 93-98.
Abstract:
Helice tientsinensis burrow in the intertidal mudflats and estuaries especially in the high intertidal and supralittoral zones along the coast of northern China. The mature specimens were collected from Rongcheng, Weihai, China. The salinity and temperature tolerance of the mud-flat crab, Helice tientsinensis, were investigated in the laboratory. The salinity tolerance experiment was conducted at 10℃, 20℃ and 30℃. Ten salinity gradients including 65, 68, 71, 74, 77, 80, 83, 86, 89 and 92 at 10℃, and 56, 59, 62, 65, 68, 71, 74, 77, 80 and 83 at 20℃, and 50, 53, 56, 59, 62, 65, 68, 71, 74 and 77 at 30℃ were respectively designed according to the results of pretests. The temperature tolerance experiment was conducted at salinities of 0, 30 and 50. In the low temperature tolerance test, 6℃, 7℃, 8℃ and 9℃ at 0 salinity, and 0℃, 1℃, 2℃ and 3℃ at 30 salinity, and 3℃, 4℃, 5℃ and 6℃ at 50 salinity respectively designed according to the results of pretests. In the high temperature tolerance test, 34℃, 35℃, 36℃, 37℃ and 38℃ at 0 salinity, and 36℃, 37℃, 38℃, 39℃ and 40℃ at 30 salinity, and 35℃, 36℃, 37℃, 38℃ and 39℃ at 50 salinity respectively designed according to the results of pretests. All treatments were triplicated with ten crabs (16±2)g assigned for each replicate. The results demonstrated that Helice tientsinensis is very tolerant of extreme salinities, and is more tolerant of salinity than several other euryhaline crab species. The mud-flat crabs could survive 96 h in 0 solution at a temperature range of 9～34℃. In hyper-media, values of 96 h LS50, 96 h survival rates of 100% and mortalities of 100% were 72.3, 63.2 and 57.8, and 65, 56 and 50,and 83,74 and 68 at 10℃, 20℃ and 30℃, respectively. Helice tientsinensis tolerate a broad range of temperature condition. The minimum and maximum temperatures that the crabs survived 96 h were 9℃, 2℃and 6℃, and 34℃, 36℃ and 35℃ in solutions of 0, 30 and 50, respectively. In thermal tolerance experiments, the crabs survived 24 h in solutions of 50, 30 and 0 at 38℃, 39℃ and 35℃, respectively, but a sharp rise in mortality of the crabs occurred after 48h of the tolerance experiments. The results showed that the interaction of salinity and temperature significantly affected the survival of Helice tientsinensis(P<0.05). Elevated temperature (range 10-30) decreased the crab's solute tolerance, and sharp changes of the salinity (range 30-50 or 30-0) decreased the crab's temperature tolerance.
Helice tientsinensis burrow in the intertidal mudflats and estuaries especially in the high intertidal and supralittoral zones along the coast of northern China. The mature specimens were collected from Rongcheng, Weihai, China. The salinity and temperature tolerance of the mud-flat crab, Helice tientsinensis, were investigated in the laboratory. The salinity tolerance experiment was conducted at 10℃, 20℃ and 30℃. Ten salinity gradients including 65, 68, 71, 74, 77, 80, 83, 86, 89 and 92 at 10℃, and 56, 59, 62, 65, 68, 71, 74, 77, 80 and 83 at 20℃, and 50, 53, 56, 59, 62, 65, 68, 71, 74 and 77 at 30℃ were respectively designed according to the results of pretests. The temperature tolerance experiment was conducted at salinities of 0, 30 and 50. In the low temperature tolerance test, 6℃, 7℃, 8℃ and 9℃ at 0 salinity, and 0℃, 1℃, 2℃ and 3℃ at 30 salinity, and 3℃, 4℃, 5℃ and 6℃ at 50 salinity respectively designed according to the results of pretests. In the high temperature tolerance test, 34℃, 35℃, 36℃, 37℃ and 38℃ at 0 salinity, and 36℃, 37℃, 38℃, 39℃ and 40℃ at 30 salinity, and 35℃, 36℃, 37℃, 38℃ and 39℃ at 50 salinity respectively designed according to the results of pretests. All treatments were triplicated with ten crabs (16±2)g assigned for each replicate. The results demonstrated that Helice tientsinensis is very tolerant of extreme salinities, and is more tolerant of salinity than several other euryhaline crab species. The mud-flat crabs could survive 96 h in 0 solution at a temperature range of 9～34℃. In hyper-media, values of 96 h LS50, 96 h survival rates of 100% and mortalities of 100% were 72.3, 63.2 and 57.8, and 65, 56 and 50,and 83,74 and 68 at 10℃, 20℃ and 30℃, respectively. Helice tientsinensis tolerate a broad range of temperature condition. The minimum and maximum temperatures that the crabs survived 96 h were 9℃, 2℃and 6℃, and 34℃, 36℃ and 35℃ in solutions of 0, 30 and 50, respectively. In thermal tolerance experiments, the crabs survived 24 h in solutions of 50, 30 and 0 at 38℃, 39℃ and 35℃, respectively, but a sharp rise in mortality of the crabs occurred after 48h of the tolerance experiments. The results showed that the interaction of salinity and temperature significantly affected the survival of Helice tientsinensis(P<0.05). Elevated temperature (range 10-30) decreased the crab's solute tolerance, and sharp changes of the salinity (range 30-50 or 30-0) decreased the crab's temperature tolerance.
2014, 36(2): 99-107.
Abstract:
Lipid plays an important role in reproduction, food scarcity and diapause of zooplankton. The present research studied the role of lipids in Calanus sinicus, and samples were collected from the Southern Yellow Sea in autumn (November, 2010) and spring (April, 2011). The results show that the total lipid content of female C. sinicus was about 10.6%-12% of dry body mass, while C5 stage in spring had a higher percentage, about 17% of dry mass. The major components in lipid classes were wax ester (WE) and phospholipid (PL), and they together contributed about 90% to total lipid, while triglyceride (TAG) accounted for only 6%. The role of different lipid classes was discussed as follows: (1) Wax ester served as an important energy deposit. The fluctuated WE content of C. sinicus suggested the different strategies in energy needs and utilization of different development stages and seasons. (2) The coincidence of active reproduction and high content of PL in female indicated that PL plays an important role in the egg production of C. sinicus. (3) The composition of TAG was relatively lower than that of WE and PL in C. sinicus, but it might work in the transformation of different lipid classes.
Lipid plays an important role in reproduction, food scarcity and diapause of zooplankton. The present research studied the role of lipids in Calanus sinicus, and samples were collected from the Southern Yellow Sea in autumn (November, 2010) and spring (April, 2011). The results show that the total lipid content of female C. sinicus was about 10.6%-12% of dry body mass, while C5 stage in spring had a higher percentage, about 17% of dry mass. The major components in lipid classes were wax ester (WE) and phospholipid (PL), and they together contributed about 90% to total lipid, while triglyceride (TAG) accounted for only 6%. The role of different lipid classes was discussed as follows: (1) Wax ester served as an important energy deposit. The fluctuated WE content of C. sinicus suggested the different strategies in energy needs and utilization of different development stages and seasons. (2) The coincidence of active reproduction and high content of PL in female indicated that PL plays an important role in the egg production of C. sinicus. (3) The composition of TAG was relatively lower than that of WE and PL in C. sinicus, but it might work in the transformation of different lipid classes.
2014, 36(2): 108-114.
Abstract:
In order to analyze the contamination of human enteric viruses in bathing beach and economic shellfish along the primarily commercial shellfish-breeding areas in coastal cities, we chose adenovirus as the object of this study. Virus was concentrated by efficient ultra-centrifuge method, then TaqMan real-time PCR was employed to quantify its concentration. The percentage of positive samples for adenovirus was 35%in ten bathing beaches of China. The concentration was 1.1×107-2.8×107 copies/L. The viral incidence in the water samples collected from 100 meters off the seashore was found not to be correlated with those from 1 000 meters out (p>0.05). The percentage of positive samples for adenovirus was 11.7% in 162 samples, the concentration ranged from 2.4×104 to 3.1×105 copies/g. During six chosen commercial shellfish, Oyster apparently had the strongest ability to carry adenovirus. Hence, the contamination of seawater and shellfish by human adenovirus was relatively common. The fecal contamination in Shandong Province, Liaoning Province and Zhejiang Province were more severe, indicating a potential public health threat for bathers and consumers. Human enteric adenovirus was a good indicator to present the fecal pollution. Therefore, investigating its distribution from bathing beach and commercial shellfish may help to alert community health to enteric viruses that are in circulation in the population. This study laid a good foundation for carrying out the risk assessment and molecular epidemiological investigation of adenovirus in the whole China.
In order to analyze the contamination of human enteric viruses in bathing beach and economic shellfish along the primarily commercial shellfish-breeding areas in coastal cities, we chose adenovirus as the object of this study. Virus was concentrated by efficient ultra-centrifuge method, then TaqMan real-time PCR was employed to quantify its concentration. The percentage of positive samples for adenovirus was 35%in ten bathing beaches of China. The concentration was 1.1×107-2.8×107 copies/L. The viral incidence in the water samples collected from 100 meters off the seashore was found not to be correlated with those from 1 000 meters out (p>0.05). The percentage of positive samples for adenovirus was 11.7% in 162 samples, the concentration ranged from 2.4×104 to 3.1×105 copies/g. During six chosen commercial shellfish, Oyster apparently had the strongest ability to carry adenovirus. Hence, the contamination of seawater and shellfish by human adenovirus was relatively common. The fecal contamination in Shandong Province, Liaoning Province and Zhejiang Province were more severe, indicating a potential public health threat for bathers and consumers. Human enteric adenovirus was a good indicator to present the fecal pollution. Therefore, investigating its distribution from bathing beach and commercial shellfish may help to alert community health to enteric viruses that are in circulation in the population. This study laid a good foundation for carrying out the risk assessment and molecular epidemiological investigation of adenovirus in the whole China.
2014, 36(2): 115-122.
Abstract:
To investigate phylogenetic and enzyme production diversity of moderately halophilic bacteria, we got the samples from China's offshore of Tianjing, Shandong, Jiangsu, Fujian and Hainan. 108 moderately halophilic strains were isolated, 26 of which could produce at least one type of enzymes. According to physiological and biochemical characteristics, 16S rRNA sequences and phylogenetic analysis, the 26 moderately halophilic strains belonged to genera Halomonas, Idiomarina, Virgibacillus, Pontibacillus, Oceanobacillus, Halobacillus or Marinilactibacillus separately. The sequences had the similarity(97%-100%) to the type strains of each genera. Some moderately halophilic bacteria might be a novel species. The substrates specific experiment indicated that there were 13 moderately halophilic strains producing protease, 19 strains producing amylase, 13 strains producing esterase, 4 strains producing cellulose. And there were 6 strains producing three enzymes and 11 strains producing two enzymes simultaneously. The research indicated that there was not only abundant phylogenetic and enzyme diversity of moderately halophilic bacteria, but also some unknown bacteria groups existed in China's offshore, which provided references for reasonable development and utilization of halophilic microbial resources.
To investigate phylogenetic and enzyme production diversity of moderately halophilic bacteria, we got the samples from China's offshore of Tianjing, Shandong, Jiangsu, Fujian and Hainan. 108 moderately halophilic strains were isolated, 26 of which could produce at least one type of enzymes. According to physiological and biochemical characteristics, 16S rRNA sequences and phylogenetic analysis, the 26 moderately halophilic strains belonged to genera Halomonas, Idiomarina, Virgibacillus, Pontibacillus, Oceanobacillus, Halobacillus or Marinilactibacillus separately. The sequences had the similarity(97%-100%) to the type strains of each genera. Some moderately halophilic bacteria might be a novel species. The substrates specific experiment indicated that there were 13 moderately halophilic strains producing protease, 19 strains producing amylase, 13 strains producing esterase, 4 strains producing cellulose. And there were 6 strains producing three enzymes and 11 strains producing two enzymes simultaneously. The research indicated that there was not only abundant phylogenetic and enzyme diversity of moderately halophilic bacteria, but also some unknown bacteria groups existed in China's offshore, which provided references for reasonable development and utilization of halophilic microbial resources.
2014, 36(2): 123-129.
Abstract:
On the basis of the fact that Chaetoceros curvisetus showed allelopathic effect on Skeletonema costatum, a series of experiments, including algal cultures and compounds extraction, were carried out to research the properties, influence factors, degradation characteristics and structure of C. curvisetus allelochemical. The results indicated that allelopathic effect of C. curvisetus was related to the growth phase, and the C. curvisetus filtrates in exponential phase caused the inhibition on the growth of S. costatum than that of declining phase filtrates. Chaetoceros curvisetus allelochemical remain stable under 50℃ temperature and degraded as time went on attributed on light and bacteria, and bacteria contributed more. Furthermore, the ethyl acetate extraction of C. curvisetus filtrate showed significant allelopathic effect and the wavelength of characteristic absorption for the growth inhibitor was 255-260 nm. Consequently, the effect ingredient was dissolved by ethyl acetate. In addition, the allelochemical of C. curvisetus was supported to be benzene derivatives whose decomposition temperature was more than 50℃ and could be degraded by light and bacteria.
On the basis of the fact that Chaetoceros curvisetus showed allelopathic effect on Skeletonema costatum, a series of experiments, including algal cultures and compounds extraction, were carried out to research the properties, influence factors, degradation characteristics and structure of C. curvisetus allelochemical. The results indicated that allelopathic effect of C. curvisetus was related to the growth phase, and the C. curvisetus filtrates in exponential phase caused the inhibition on the growth of S. costatum than that of declining phase filtrates. Chaetoceros curvisetus allelochemical remain stable under 50℃ temperature and degraded as time went on attributed on light and bacteria, and bacteria contributed more. Furthermore, the ethyl acetate extraction of C. curvisetus filtrate showed significant allelopathic effect and the wavelength of characteristic absorption for the growth inhibitor was 255-260 nm. Consequently, the effect ingredient was dissolved by ethyl acetate. In addition, the allelochemical of C. curvisetus was supported to be benzene derivatives whose decomposition temperature was more than 50℃ and could be degraded by light and bacteria.
2014, 36(2): 130-136.
Abstract:
Investigation into seafloor hydrothermal activity and its surroundings has been one key point of studying ocean sciences. Physical and chemical parameters obtained from the hydrothermal environments would be influenced by the tide, especially from the shallow hydrothermal vent. It is distributing many hydrothermal vents on the less than 30 meter shallow seafloor of Kueishantao Islet, Northeast offshore Taiwan Island, close to the southern Okinawa Trough. Zhejiang University, Hangzhou Dianzi University, and Taiwan Sun Yat-sen University together carried a joint investigation into seafloor hydrothermal near Kueishan island sea area and obtained continuous temperature and pH field observation data of a low-temperature hydrothermal vent (24.83414°N, 121.961 91°E) for about 87 hours. Based on Morlet complex wavelet transform method, after compared the calculating results with the recorded tidal height variance, the potential periodic relationship between temperature and pH field observed time series of shallow hydrothermal vent and tide signal can be studied. The result evidenced that tide is the main impact factor for field investigating seafloor physical and chemical parameters of white hydrothermal vent. The wavelet coefficients of the in-situ temperature and pH data after Morlet complex wavelet transform exist regular 12.9 h and 12.5 h periods. Besides, wavelet coefficients of the temperature are negative correlated with the tidal height at this semi-diurnal time scale with the correlation coefficient -0.89, and pH wavelet coefficient is the opposite case with the correlation coefficient 0.76.
Investigation into seafloor hydrothermal activity and its surroundings has been one key point of studying ocean sciences. Physical and chemical parameters obtained from the hydrothermal environments would be influenced by the tide, especially from the shallow hydrothermal vent. It is distributing many hydrothermal vents on the less than 30 meter shallow seafloor of Kueishantao Islet, Northeast offshore Taiwan Island, close to the southern Okinawa Trough. Zhejiang University, Hangzhou Dianzi University, and Taiwan Sun Yat-sen University together carried a joint investigation into seafloor hydrothermal near Kueishan island sea area and obtained continuous temperature and pH field observation data of a low-temperature hydrothermal vent (24.83414°N, 121.961 91°E) for about 87 hours. Based on Morlet complex wavelet transform method, after compared the calculating results with the recorded tidal height variance, the potential periodic relationship between temperature and pH field observed time series of shallow hydrothermal vent and tide signal can be studied. The result evidenced that tide is the main impact factor for field investigating seafloor physical and chemical parameters of white hydrothermal vent. The wavelet coefficients of the in-situ temperature and pH data after Morlet complex wavelet transform exist regular 12.9 h and 12.5 h periods. Besides, wavelet coefficients of the temperature are negative correlated with the tidal height at this semi-diurnal time scale with the correlation coefficient -0.89, and pH wavelet coefficient is the opposite case with the correlation coefficient 0.76.
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