2012 Vol. 34, No. 2
Display Method:
2012, 34(2): 1-12.
Abstract:
Based on the Finite Volume Coastal and Ocean Model (FVCOM), an unstructured ocean tidal numerical model with high resolution was built in northwest Pacific, including the marginal seas adjacent to China, Japan/East Sea and Okhotsk Sea. The model was in a spherical coordinate and took into account the effects of non-linear and tide-generating force. The tidal datasets from 84 tide-gauges along the coast were assimilated into the model with Nudging method. Comparing with the other 175 tidal stations which were not assimilated in this model, the simulated results were well agree with the observations, with the absolute mean errors of amplitude and phase-lag 4.0 cm and 5.6° for M2 constituent, 2.4 cm and 7.5° for S2 constituent, 2.6 cm and 6.3° for K1 constituent, 1.5 cm and 5.0° for O1 constituent, respectively. According to the co-tidal charts for the four major constituents by harmonic analysis, 8 amphidromic points for the semi-diurnal tides and 5 amphidromic points for the diurnal tides were found. The existence of amphidromic point for the diurnal tides in Soya strait was confirmed by the model results and we documented first an amphidromic point for the diurnal tides in Tsugaru strait. The distribution for the maximum possible tidal ranges and the tide residual water level were obtained in the whole model domain.
Based on the Finite Volume Coastal and Ocean Model (FVCOM), an unstructured ocean tidal numerical model with high resolution was built in northwest Pacific, including the marginal seas adjacent to China, Japan/East Sea and Okhotsk Sea. The model was in a spherical coordinate and took into account the effects of non-linear and tide-generating force. The tidal datasets from 84 tide-gauges along the coast were assimilated into the model with Nudging method. Comparing with the other 175 tidal stations which were not assimilated in this model, the simulated results were well agree with the observations, with the absolute mean errors of amplitude and phase-lag 4.0 cm and 5.6° for M2 constituent, 2.4 cm and 7.5° for S2 constituent, 2.6 cm and 6.3° for K1 constituent, 1.5 cm and 5.0° for O1 constituent, respectively. According to the co-tidal charts for the four major constituents by harmonic analysis, 8 amphidromic points for the semi-diurnal tides and 5 amphidromic points for the diurnal tides were found. The existence of amphidromic point for the diurnal tides in Soya strait was confirmed by the model results and we documented first an amphidromic point for the diurnal tides in Tsugaru strait. The distribution for the maximum possible tidal ranges and the tide residual water level were obtained in the whole model domain.
2012, 34(2): 13-22.
Abstract:
Hydrographic data from three cruises during 2006 and 2008 and historical temperature data from Japan Oceanographic Data Center (JODC) were used to study temperature inversion (TI) in the Taiwan Strait during northeast monsoon. The result shows that TI occurs almost in the whole strait except Taiwan Bank and shallow waters along western coast of the strait. The magnitude (occurrence frequency) of TI is large (high) in the western strait, but small (low) in the eastern strait and the coastal waters of Guandong. The start depths of TI layers are deeper in spring than that in autumn and winter. The area where TI occurs frequently (ATOF) with occurrence frequency above 60% has a southnorth movement with seasons. The southern edge of ATOF locates around Xiamen coastal sea in autumn and extends southward to the north of Taiwan Bank in winter, and then recedes northward to Pingtan coastal sea in spring. The seasonal southnorth migration of ZheMin Coastal Water (ZMCW) is found to induce ATOF’s movement. Besides seasonal variability, there was a distinct difference of TI between 2006 and 2007 winter. TI only occurred in the coastal area of western strait during 2006 winter, but in the western and eastern strait and the coastal waters of Guandong during 2007 winter. The lateral shift of ZMCW is suggested to be the major causative factor.
Hydrographic data from three cruises during 2006 and 2008 and historical temperature data from Japan Oceanographic Data Center (JODC) were used to study temperature inversion (TI) in the Taiwan Strait during northeast monsoon. The result shows that TI occurs almost in the whole strait except Taiwan Bank and shallow waters along western coast of the strait. The magnitude (occurrence frequency) of TI is large (high) in the western strait, but small (low) in the eastern strait and the coastal waters of Guandong. The start depths of TI layers are deeper in spring than that in autumn and winter. The area where TI occurs frequently (ATOF) with occurrence frequency above 60% has a southnorth movement with seasons. The southern edge of ATOF locates around Xiamen coastal sea in autumn and extends southward to the north of Taiwan Bank in winter, and then recedes northward to Pingtan coastal sea in spring. The seasonal southnorth migration of ZheMin Coastal Water (ZMCW) is found to induce ATOF’s movement. Besides seasonal variability, there was a distinct difference of TI between 2006 and 2007 winter. TI only occurred in the coastal area of western strait during 2006 winter, but in the western and eastern strait and the coastal waters of Guandong during 2007 winter. The lateral shift of ZMCW is suggested to be the major causative factor.
2012, 34(2): 23-29.
Abstract:
The ocean waves are generally a mixer of wind-wave and swell. In this paper,a two-dimensional(2D) wave spectrum partitioning techniques and three one-dimensional(1D) wave spectrum partitioning techniques (i.e. PM technique, WH technique, JP technique) used to identify wind-wave and swell are examined based on the model results and the observations, it is shown that the 2D technique could provide most reliable results; compared with 2D technique, PM technique obviously overestimates the wind-wave components, WH technique overestimates the energy of wind-wave at low wind speed, while shows better agreement with 2D technique at higher winds, overestimations also occur in the case of JP technique; PM technique is modified to show better agreement with the 2D scheme, it is found that the improved PM technique provides most consistent results with the 2D scheme among the 1D techniques.
The ocean waves are generally a mixer of wind-wave and swell. In this paper,a two-dimensional(2D) wave spectrum partitioning techniques and three one-dimensional(1D) wave spectrum partitioning techniques (i.e. PM technique, WH technique, JP technique) used to identify wind-wave and swell are examined based on the model results and the observations, it is shown that the 2D technique could provide most reliable results; compared with 2D technique, PM technique obviously overestimates the wind-wave components, WH technique overestimates the energy of wind-wave at low wind speed, while shows better agreement with 2D technique at higher winds, overestimations also occur in the case of JP technique; PM technique is modified to show better agreement with the 2D scheme, it is found that the improved PM technique provides most consistent results with the 2D scheme among the 1D techniques.
2012, 34(2): 30-38.
Abstract:
Based on the ocean reanalysis data sets and observations, the authors analyze the west-east water mass exchange in the central Indian Ocean. It is found that there are two independent processes in the equatorial Indian Ocean(EIO, 2°S-2°N) and the North Indian Ocean(NIO, 4°-6°N), respectively. The NIO process is mainly induced by monsoon current, which advects low-salinity water westward from November to March, and during May-September the high-salinity water is carried to the east. The westward advection is stronger than the eastward, so the annual mean shows westward. The EIO process can be divided into the surface and the subsurface process. The surface equatorial process driven by equatorial wind is characterized by a semiannual cycle. During April-May and October-November, the high-salinity water of Arabian Sea is transported eastward, and the low-salinity water of Bay of Bengal westward in the other months. The annual mean advoction is eastward. The high-salinity water is eastward conveyed by subsurface equatorial process all year around.
Based on the ocean reanalysis data sets and observations, the authors analyze the west-east water mass exchange in the central Indian Ocean. It is found that there are two independent processes in the equatorial Indian Ocean(EIO, 2°S-2°N) and the North Indian Ocean(NIO, 4°-6°N), respectively. The NIO process is mainly induced by monsoon current, which advects low-salinity water westward from November to March, and during May-September the high-salinity water is carried to the east. The westward advection is stronger than the eastward, so the annual mean shows westward. The EIO process can be divided into the surface and the subsurface process. The surface equatorial process driven by equatorial wind is characterized by a semiannual cycle. During April-May and October-November, the high-salinity water of Arabian Sea is transported eastward, and the low-salinity water of Bay of Bengal westward in the other months. The annual mean advoction is eastward. The high-salinity water is eastward conveyed by subsurface equatorial process all year around.
2012, 34(2): 39-47.
Abstract:
In this paper, the physical mechanism how tsunami was trigered by submarine earthquake, the characteristic of tsunamis wave propagated in ocean and potential disaster caused by the super-destructive power of tsunamis were presented simply. The frequency of global tsunamis occurred and the temporal and spatial distribution of historical tsunamis in Pacific region were outlined. The frequency and spatial distribution of the tsunamis which occurred in China coasts were also systemized. According to trans-oceanic tsunami propagation mechanism, selecting a tsunami numerical model which was developed at the University of Washington. It is based on wave tracking theory and adaptive mesh refinement technology. Focus on simulating tsunami wave propagation characteristics around China’s coastal areas, the simulation results fit well with the observational data. Based on the simulation results,the impact of Chile tsunami on China coasts was discussed quantitatively. The evaluation of potential risk along the China coasts was given.
In this paper, the physical mechanism how tsunami was trigered by submarine earthquake, the characteristic of tsunamis wave propagated in ocean and potential disaster caused by the super-destructive power of tsunamis were presented simply. The frequency of global tsunamis occurred and the temporal and spatial distribution of historical tsunamis in Pacific region were outlined. The frequency and spatial distribution of the tsunamis which occurred in China coasts were also systemized. According to trans-oceanic tsunami propagation mechanism, selecting a tsunami numerical model which was developed at the University of Washington. It is based on wave tracking theory and adaptive mesh refinement technology. Focus on simulating tsunami wave propagation characteristics around China’s coastal areas, the simulation results fit well with the observational data. Based on the simulation results,the impact of Chile tsunami on China coasts was discussed quantitatively. The evaluation of potential risk along the China coasts was given.
2012, 34(2): 48-56.
Abstract:
Based on the monthly-mean Extended Reconstruction sea surface temperature data (ERSST. V3) from NOAA, the primary modes of the boreal wintertime (December-next year’s Feburary) SST anomalies (SSTA) from 1950/1951 to 2008/2009 in the South Pacific and their relationships with ENSO are studied. The results show that there are two dominant modes in the boreal wintertime of South Pacific, and the first mode with a periodicity of 11-16 a represents an interdecadal fluctuation with response in the north part of South Pacific and out of phase fluctuations of moderate amplitude in the south part of South Pacific,the second mode with a periodicity of 18-24 a also has an interdecadal nature with larger response in the west of South Pacific and out of phase fluctuations of smaller amplitude in the east of South Pacific. The interannual timescale characteristic of the two modes aren’t evident. The first mode coincides well with the occurrence of the ENSO event, and the second mode has an impact on the occurrence of ENSO in the next year. In order to study their interannual and interdecadal characteristic, their time series have been high-pass filtered and low-pass filtered respectively. After filtering, the relationship between the two modes and ENSO is consonant with the relationship before filtering in the interannual time scale. In the interdecadal time scale, the interdecadal variations of the first mode may respond to the interdecadal variations of ENSO event, and the second mode may not only have response to the former ENSO event but also have impact on the latter ENSO event to some extent.
Based on the monthly-mean Extended Reconstruction sea surface temperature data (ERSST. V3) from NOAA, the primary modes of the boreal wintertime (December-next year’s Feburary) SST anomalies (SSTA) from 1950/1951 to 2008/2009 in the South Pacific and their relationships with ENSO are studied. The results show that there are two dominant modes in the boreal wintertime of South Pacific, and the first mode with a periodicity of 11-16 a represents an interdecadal fluctuation with response in the north part of South Pacific and out of phase fluctuations of moderate amplitude in the south part of South Pacific,the second mode with a periodicity of 18-24 a also has an interdecadal nature with larger response in the west of South Pacific and out of phase fluctuations of smaller amplitude in the east of South Pacific. The interannual timescale characteristic of the two modes aren’t evident. The first mode coincides well with the occurrence of the ENSO event, and the second mode has an impact on the occurrence of ENSO in the next year. In order to study their interannual and interdecadal characteristic, their time series have been high-pass filtered and low-pass filtered respectively. After filtering, the relationship between the two modes and ENSO is consonant with the relationship before filtering in the interannual time scale. In the interdecadal time scale, the interdecadal variations of the first mode may respond to the interdecadal variations of ENSO event, and the second mode may not only have response to the former ENSO event but also have impact on the latter ENSO event to some extent.
2012, 34(2): 57-62.
Abstract:
Coral reefs are the high ecological system of biodiversity and have an important ecological function. After the 1980s large degradation of global scope of coral reefs caused people wide attention. Using high resolution images based on Quickbird data, coral reefs geometry parameters and development index the Nansha typical reef development is monitored through remote sensing In the waters against the wind, coral reefs bodies there are the texture characteristics, which shows that the sea surface roughness and underwater reef development characteristics. The results show that because Nansha reefs are inflnencdby geologiy and climate, development degree is differ, half moon reef development is better, development index is 0.38, the reef development index of 0.27. Geometry parameters to are estabtished monitor the Nansha coral reef development status which can provide the scientific basis the protection of the coral reefs.
Coral reefs are the high ecological system of biodiversity and have an important ecological function. After the 1980s large degradation of global scope of coral reefs caused people wide attention. Using high resolution images based on Quickbird data, coral reefs geometry parameters and development index the Nansha typical reef development is monitored through remote sensing In the waters against the wind, coral reefs bodies there are the texture characteristics, which shows that the sea surface roughness and underwater reef development characteristics. The results show that because Nansha reefs are inflnencdby geologiy and climate, development degree is differ, half moon reef development is better, development index is 0.38, the reef development index of 0.27. Geometry parameters to are estabtished monitor the Nansha coral reef development status which can provide the scientific basis the protection of the coral reefs.
2012, 34(2): 63-72.
Abstract:
The coastal area of Zhejiang and Fujian is one of the red tide-prone areas in China which is a good place for the study of the scavenging of aluminum by the phytoplankton from seawater. Two cruises were carried out in the coastal area of Zhejiang and Fujian in May 2007 and May 2008, respectively. The distribution of dissolved aluminum concentration is investigated, and the influencing factors including the water mass mixing, suspended particles and phytoplankton bloom are discussed. The distribution of dissolved aluminum concentration showed higher in the near coastal area and the near-bottom layer, and there is no significant interannual variation through statistical analysis. The water mass mixing and the sediment re-suspension are the main influencing factors of the distribution of dissolved aluminum concentration. In addition, the phytoplankton bloom also has a scavenging effect on the dissolved aluminum concentration.
The coastal area of Zhejiang and Fujian is one of the red tide-prone areas in China which is a good place for the study of the scavenging of aluminum by the phytoplankton from seawater. Two cruises were carried out in the coastal area of Zhejiang and Fujian in May 2007 and May 2008, respectively. The distribution of dissolved aluminum concentration is investigated, and the influencing factors including the water mass mixing, suspended particles and phytoplankton bloom are discussed. The distribution of dissolved aluminum concentration showed higher in the near coastal area and the near-bottom layer, and there is no significant interannual variation through statistical analysis. The water mass mixing and the sediment re-suspension are the main influencing factors of the distribution of dissolved aluminum concentration. In addition, the phytoplankton bloom also has a scavenging effect on the dissolved aluminum concentration.
2012, 34(2): 73-83.
Abstract:
Based on the data of suspended matter collected from the southern Huanghai Sea investigation during 2006-2007,the distribution of the suspended matter and its transport trend were analyzed.It was focused on an analysis of the horizontal distribution of the suspended matter and its transport trend.The result shows that the distribution of the suspended matter has significant spatial-regional characteristics,which is in good correlation with the arrangement of a circulation.Seasonal transition circulations are the main dynamic and controlling factors of the suspended matter transport.Jiangsu coast is the highest region of the suspended matter concentration all the year around,the sediment resuspension caused by tide and wave as well as the carrying and transportation of North Jiangsu Province coastal water are the main source of the suspended matter in this area.Moreover,the cumulation of the suspended matter in Jiangsu coast in summer can also provide a necessary mechanism for its transportation to the southeastern sea area,due to the influence of the Huanghai Sea Western Coastal Current in winter half year.In spring,summer and autumn,a noticeable high-concentration area exists in the northeast sea of the Changjiang Estuary and extends to the northeast,due to the effect of the Changjiang diluted water.As a result of the modern Huanghe River mass transportation caused by the North Shandong Province Coastal Current,a high-concentration area of the suspended matter also exists in Shidao coastal sea in winter,spring and autumn,and has the trend of spreading to the mud area in the central part of the southern Huanghai Sea.Meanwhile,it also is found that there was a high-concentration area displaying cloudy distribution in the surface and bottom water of the central investigation area in spring and autumn.And the "double peaks"phenomenon of the suspended matter concentration exists from spring to autumn,which has the close relationship with the organic debris produced by the phytoplankton during spring and autumn blooming that can make the marine plankton organic matter as the suspended solids shift to the sediments.It is further pointed out that the above-mentioned matter source may play an important role in the formation and growth of the southern Huanghai Sea cold eddy mud area.Obviously,this viewpoint intensified the understandings of the impact of biological activities in the upper water on the cold eddy mud area in the central southern Huanghai Sea and the matter source of the mud area.
Based on the data of suspended matter collected from the southern Huanghai Sea investigation during 2006-2007,the distribution of the suspended matter and its transport trend were analyzed.It was focused on an analysis of the horizontal distribution of the suspended matter and its transport trend.The result shows that the distribution of the suspended matter has significant spatial-regional characteristics,which is in good correlation with the arrangement of a circulation.Seasonal transition circulations are the main dynamic and controlling factors of the suspended matter transport.Jiangsu coast is the highest region of the suspended matter concentration all the year around,the sediment resuspension caused by tide and wave as well as the carrying and transportation of North Jiangsu Province coastal water are the main source of the suspended matter in this area.Moreover,the cumulation of the suspended matter in Jiangsu coast in summer can also provide a necessary mechanism for its transportation to the southeastern sea area,due to the influence of the Huanghai Sea Western Coastal Current in winter half year.In spring,summer and autumn,a noticeable high-concentration area exists in the northeast sea of the Changjiang Estuary and extends to the northeast,due to the effect of the Changjiang diluted water.As a result of the modern Huanghe River mass transportation caused by the North Shandong Province Coastal Current,a high-concentration area of the suspended matter also exists in Shidao coastal sea in winter,spring and autumn,and has the trend of spreading to the mud area in the central part of the southern Huanghai Sea.Meanwhile,it also is found that there was a high-concentration area displaying cloudy distribution in the surface and bottom water of the central investigation area in spring and autumn.And the "double peaks"phenomenon of the suspended matter concentration exists from spring to autumn,which has the close relationship with the organic debris produced by the phytoplankton during spring and autumn blooming that can make the marine plankton organic matter as the suspended solids shift to the sediments.It is further pointed out that the above-mentioned matter source may play an important role in the formation and growth of the southern Huanghai Sea cold eddy mud area.Obviously,this viewpoint intensified the understandings of the impact of biological activities in the upper water on the cold eddy mud area in the central southern Huanghai Sea and the matter source of the mud area.
2012, 34(2): 84-91.
Abstract:
As the effect of natural accreting processes and artificial reclamation, the river channel of the North Branch in the Changjiang Estuary has narrowed significantly, and the position of summit of the funnel-shape has moved down. As an important strong tidal bifurcation of the Changjiang Estuary, the transport characteristics of suspended sediment in the North Branch is deserving of further discussion and research by considering the changes in river morphology and sediment load from the Changjiang drainage area.According to the continuousl observation of flow and sediment during one spring-neap tide cycle in April 2010, together with historical data from different locations, the obtained results are as follows: the current is strong and suspended scdiment content(SSC) comparatively high in the North Branch, the process curve of the SSC shows a pattern of "unimodal-bimodal-unimodal"in a half 14 d cycel. Lagrangian advection and tidal pumping effect are two main constituents of sediment transport in the North Branch, with spatial variations.Touxing Port can be considered as a transition, where Lagrangian sediment transport dominantes in the upper mouth and the tidal pumping in the lower section. As for the net sediment transport flux, it moved seaward in upper mouth and landward in the lower section. The result suggests a turbidity maximum due to sediment accumulation around the summit.
As the effect of natural accreting processes and artificial reclamation, the river channel of the North Branch in the Changjiang Estuary has narrowed significantly, and the position of summit of the funnel-shape has moved down. As an important strong tidal bifurcation of the Changjiang Estuary, the transport characteristics of suspended sediment in the North Branch is deserving of further discussion and research by considering the changes in river morphology and sediment load from the Changjiang drainage area.According to the continuousl observation of flow and sediment during one spring-neap tide cycle in April 2010, together with historical data from different locations, the obtained results are as follows: the current is strong and suspended scdiment content(SSC) comparatively high in the North Branch, the process curve of the SSC shows a pattern of "unimodal-bimodal-unimodal"in a half 14 d cycel. Lagrangian advection and tidal pumping effect are two main constituents of sediment transport in the North Branch, with spatial variations.Touxing Port can be considered as a transition, where Lagrangian sediment transport dominantes in the upper mouth and the tidal pumping in the lower section. As for the net sediment transport flux, it moved seaward in upper mouth and landward in the lower section. The result suggests a turbidity maximum due to sediment accumulation around the summit.
2012, 34(2): 92-100.
Abstract:
The contents of metals in surface sediments of the Laizhou Bay in the Bohai Sea were determined by the X-ray fluorescence, the inductively coupled plasma mass spectroscopy or the atomic fluorescence spectrometer. Results show that the contents of copper,zinc,lead,cadmium,nickel,chromium,cobalt,vanadium,scandium,iron and manganese decrease gradually from the coastal area to the central, and their contents are higher in the southern area than those in the northern. However, the relatively higher contents of silven were observed in the middle-southwestern sea of this area. A risk assessment of heavy metals, based on the marine sediment quality standards, indicates that adverse biological effects caused by arsenic and nickel occasionally may take place in the sediments of the Laizhou Bay. Enrichment factors were calculated to weigh whether the contents observed represented background or contaminate levels. The results reveal three groups of elements: (1)Iron,copper,zinc,cadmium,nickel,cobalt,manganese,vanadium and scandium are at background contents; (2)arsenic is the slight enriched element; and (3)lead and silven are the moderate enriched elements. A principal component analysis and EFs reveal that iron,copper,zine,cadmium,arsenic chromium,nickel,cobalt,manganese,vanadium and scandium are mainly originated from terrestrial (rock and soil)weathering, lead may have some anthropogenic sources, and silver in sediments is mainly derived from anthropogenic sources.A cluster analysis showed that the sediments from 31 stations could be divided into four groups. Two zones were identified to be relatively heavy contaminated by both arsenic and nickel in the bay. One was the northwest of the Huanghe Estuary and the other was the central-north side of the Laizhou Bay.
The contents of metals in surface sediments of the Laizhou Bay in the Bohai Sea were determined by the X-ray fluorescence, the inductively coupled plasma mass spectroscopy or the atomic fluorescence spectrometer. Results show that the contents of copper,zinc,lead,cadmium,nickel,chromium,cobalt,vanadium,scandium,iron and manganese decrease gradually from the coastal area to the central, and their contents are higher in the southern area than those in the northern. However, the relatively higher contents of silven were observed in the middle-southwestern sea of this area. A risk assessment of heavy metals, based on the marine sediment quality standards, indicates that adverse biological effects caused by arsenic and nickel occasionally may take place in the sediments of the Laizhou Bay. Enrichment factors were calculated to weigh whether the contents observed represented background or contaminate levels. The results reveal three groups of elements: (1)Iron,copper,zinc,cadmium,nickel,cobalt,manganese,vanadium and scandium are at background contents; (2)arsenic is the slight enriched element; and (3)lead and silven are the moderate enriched elements. A principal component analysis and EFs reveal that iron,copper,zine,cadmium,arsenic chromium,nickel,cobalt,manganese,vanadium and scandium are mainly originated from terrestrial (rock and soil)weathering, lead may have some anthropogenic sources, and silver in sediments is mainly derived from anthropogenic sources.A cluster analysis showed that the sediments from 31 stations could be divided into four groups. Two zones were identified to be relatively heavy contaminated by both arsenic and nickel in the bay. One was the northwest of the Huanghe Estuary and the other was the central-north side of the Laizhou Bay.
2012, 34(2): 101-113.
Abstract:
There exists unique ecological dynamic process in the estuarine maximum turbidity zone. Based on the data of velocity, chlorophyll concentration and turbidity at two mooring stations at upstream and downstream areas of the maximum turbidity zone of the Yalu River, the variations of suspended sediment and chlorophyll concentration is analyzed during neap and spring tidal cycles, and the relationship between the chlorophyll concentration and the hydrodynamic characteristion is discussed through transport flux decomposition of suspended sediment and chlorophyll. The results indicate that the distributions of higher suspended sediment concentration are consistent with thoses of chlorophyll concentration, especially in the bottom both in spring and neap tide. Sea bed sediment resuspension in the bottom caused by strong tides plays a major role in the formation of the estuarine maximum turbidity zone in the Yalu River. The relationship between the suspended sediment and chlorophyll concentrations in the bottom is higher than that in the surface, and more correlated in spring tides than that in neap tides, which, in a way, indicates that hydrodynamic characteristics have a significant impact on the distribution of chlorophyll a concentration distribution in time and space. High chlorophylla concentration distribution is mainly due to resuspension which makes the sediment and benthic algae in the bottom accumulate in bottom water. However, this conclusion remains to be tested with further research.
There exists unique ecological dynamic process in the estuarine maximum turbidity zone. Based on the data of velocity, chlorophyll concentration and turbidity at two mooring stations at upstream and downstream areas of the maximum turbidity zone of the Yalu River, the variations of suspended sediment and chlorophyll concentration is analyzed during neap and spring tidal cycles, and the relationship between the chlorophyll concentration and the hydrodynamic characteristion is discussed through transport flux decomposition of suspended sediment and chlorophyll. The results indicate that the distributions of higher suspended sediment concentration are consistent with thoses of chlorophyll concentration, especially in the bottom both in spring and neap tide. Sea bed sediment resuspension in the bottom caused by strong tides plays a major role in the formation of the estuarine maximum turbidity zone in the Yalu River. The relationship between the suspended sediment and chlorophyll concentrations in the bottom is higher than that in the surface, and more correlated in spring tides than that in neap tides, which, in a way, indicates that hydrodynamic characteristics have a significant impact on the distribution of chlorophyll a concentration distribution in time and space. High chlorophylla concentration distribution is mainly due to resuspension which makes the sediment and benthic algae in the bottom accumulate in bottom water. However, this conclusion remains to be tested with further research.
2012, 34(2): 114-121.
Abstract:
Six sediment cores, collected from Chongming tidal flat of the Changjiang Estuary in flood and dry seasons of 2007, were used to measure the sedimentation rates by the depth profiles of radionuclide excess 210Pb, and 228Th, and 7Be. Based on the constant activity model (CA), various sedimentation rates on different time scales were evaluated by excess 210Pb and 228Th, and 7Be. The results show that the sedimentation rates by excess 210Pb and 228Th, and 7Be were decreased from phragmites australis to bare flat zone. More, all the sedimentation rates were decrease from short-time to long-time scale, reflecting the tidal flat being rebuilt by hydrological dynamics. Combined with the distribution patterns of particle size of sediment on temporal and spatial scales and atmospheric deposition flux of these nuclides, the impact factors on sedimentation rate were discussed in details.
Six sediment cores, collected from Chongming tidal flat of the Changjiang Estuary in flood and dry seasons of 2007, were used to measure the sedimentation rates by the depth profiles of radionuclide excess 210Pb, and 228Th, and 7Be. Based on the constant activity model (CA), various sedimentation rates on different time scales were evaluated by excess 210Pb and 228Th, and 7Be. The results show that the sedimentation rates by excess 210Pb and 228Th, and 7Be were decreased from phragmites australis to bare flat zone. More, all the sedimentation rates were decrease from short-time to long-time scale, reflecting the tidal flat being rebuilt by hydrological dynamics. Combined with the distribution patterns of particle size of sediment on temporal and spatial scales and atmospheric deposition flux of these nuclides, the impact factors on sedimentation rate were discussed in details.
2012, 34(2): 122-128.
Abstract:
In recent years, Neobenedenia has caused serious damage on cage-cultured fish at Xiangshan Harbor, Zhejiang Province, China. The Neobenedenia adults (denoted by XSp) were collected from cultured Pseudosciaena crocea. The XSp sequences of 28S coding region of rRNA gene (28S rDNA) and the first internal transcribed spacer (ITS1) as well as morphology were studied for identification. The morphological characteristics showed that XSp belongs to Neobenedenia which was morphologically similar to Neobenedenia melleni. In XSp, the length of 28S rDNA was 393 bp and ITS1 was 427 bp. In phylogenetic analysis, Neobenedenia and Benedenia were split into two clades, and the XSp was in clade Neobenedenia. The sequences identities of 28S rDNA and ITS1 were 84.3%~89.5% and 60.2% among XSp and Benedenia, respectively. With one exception of 97.4%, the sequences identiteis of 28S rDNA and ITS1 among XSp, N. melleni and N. girellae were above 99%, which indicated that they are the same species. The results of two identification methods showed that the Neobenedenia at Xiangshan Harbor was N. melleni, and supported the opinion in which Whittington & Horton (1996) proposed that N. melleni and N. girellae were synonymy.
In recent years, Neobenedenia has caused serious damage on cage-cultured fish at Xiangshan Harbor, Zhejiang Province, China. The Neobenedenia adults (denoted by XSp) were collected from cultured Pseudosciaena crocea. The XSp sequences of 28S coding region of rRNA gene (28S rDNA) and the first internal transcribed spacer (ITS1) as well as morphology were studied for identification. The morphological characteristics showed that XSp belongs to Neobenedenia which was morphologically similar to Neobenedenia melleni. In XSp, the length of 28S rDNA was 393 bp and ITS1 was 427 bp. In phylogenetic analysis, Neobenedenia and Benedenia were split into two clades, and the XSp was in clade Neobenedenia. The sequences identities of 28S rDNA and ITS1 were 84.3%~89.5% and 60.2% among XSp and Benedenia, respectively. With one exception of 97.4%, the sequences identiteis of 28S rDNA and ITS1 among XSp, N. melleni and N. girellae were above 99%, which indicated that they are the same species. The results of two identification methods showed that the Neobenedenia at Xiangshan Harbor was N. melleni, and supported the opinion in which Whittington & Horton (1996) proposed that N. melleni and N. girellae were synonymy.
2012, 34(2): 129-135.
Abstract:
The antibacterial activity and tolerance to mimic gastrointestinal environments of the probiotic Psychrobacter sp. SE6 isolated from the gut of grouper(Epinephelus coioides)were evaluated in vitro. On the base of the in vitro results, a 60 d feeding trial was conducted to assess the effect of dietary administration(108 CFU/g) of SE6 on the growth, feed utilization and immune responses of E.coioides.In vitro results show that SE6 exhibits antagonistic activity against pathogenic Vibrio parahaemolyticus, V.harveyi, V.metschnikovi and Staphyloccocus aureus.After 2 and 4 h of incubation with artificial gastric juice at pH 4.0, the survival ratio of SE6 is 110.7% and 173%, respectively. After treated with artificial gastric juice at pH 3.0 for 2 h, the survival ratio and the survival count are 1.36% and 1.59×105 CFU/cm3, respectively. However, SE6 cannot survive in artificial gastric juice at pH 2.0.Psychrobacter sp. SE6 exhibits good tolerance to artificial intestinal juice (different concentrations of bile salt and trypsin), the survival ratios of SE6 are 89.17%, 88.33%, 77.17% and 12.33% respectively after incubated in artificial intestinal juice with 0.1%, 0.3%, 0.5% and 0.7% bile salt for 3 h. In vivo results show that Psychrobacter sp. SE6 significantly decreases the feed conversion ratio (FCR) of E.coioides.Serum lysozyme activity shows no significant differences between the probiotic group and the control group during the whole experiment period, while an increasing trend of total superoxide dismutase (T-SOD) activity in the probiotic group is observed. Serum complement component 3 (C3) level of the probiotic group is higher than that of the control in the whole feeding period, while complement component 4 (C4) level of the probiotic group is significantly higher than that of the control at Day 60. The IgM level of probiotic group is significantly higher than that of control group at Day 30, but no significant difference is observed at Day 60. In conclusion, Psychrobacter sp. SE6 shows good antagonistic activities against potential pathogens and tolerance to mimic gastrointestinal environment, and the dietary administration of Psychrobacter sp. SE6 improves the feed utilization and immune responses of E.coioides.
The antibacterial activity and tolerance to mimic gastrointestinal environments of the probiotic Psychrobacter sp. SE6 isolated from the gut of grouper(Epinephelus coioides)were evaluated in vitro. On the base of the in vitro results, a 60 d feeding trial was conducted to assess the effect of dietary administration(108 CFU/g) of SE6 on the growth, feed utilization and immune responses of E.coioides.In vitro results show that SE6 exhibits antagonistic activity against pathogenic Vibrio parahaemolyticus, V.harveyi, V.metschnikovi and Staphyloccocus aureus.After 2 and 4 h of incubation with artificial gastric juice at pH 4.0, the survival ratio of SE6 is 110.7% and 173%, respectively. After treated with artificial gastric juice at pH 3.0 for 2 h, the survival ratio and the survival count are 1.36% and 1.59×105 CFU/cm3, respectively. However, SE6 cannot survive in artificial gastric juice at pH 2.0.Psychrobacter sp. SE6 exhibits good tolerance to artificial intestinal juice (different concentrations of bile salt and trypsin), the survival ratios of SE6 are 89.17%, 88.33%, 77.17% and 12.33% respectively after incubated in artificial intestinal juice with 0.1%, 0.3%, 0.5% and 0.7% bile salt for 3 h. In vivo results show that Psychrobacter sp. SE6 significantly decreases the feed conversion ratio (FCR) of E.coioides.Serum lysozyme activity shows no significant differences between the probiotic group and the control group during the whole experiment period, while an increasing trend of total superoxide dismutase (T-SOD) activity in the probiotic group is observed. Serum complement component 3 (C3) level of the probiotic group is higher than that of the control in the whole feeding period, while complement component 4 (C4) level of the probiotic group is significantly higher than that of the control at Day 60. The IgM level of probiotic group is significantly higher than that of control group at Day 30, but no significant difference is observed at Day 60. In conclusion, Psychrobacter sp. SE6 shows good antagonistic activities against potential pathogens and tolerance to mimic gastrointestinal environment, and the dietary administration of Psychrobacter sp. SE6 improves the feed utilization and immune responses of E.coioides.
2012, 34(2): 136-142.
Abstract:
Traditionally, the mitochondrial genome sequences were usually obtained by shotgun or primers-walking combination with long PCR. The next-generation sequencing technologies are developing fastly in recent years, such as 454, Solexa and SOLiD sequencing platform. Membranipora grandicella complete mitochondrial genome sequence was determined based on next-generation high-throughput sequencing technology (Solexa) and nested PCR amplification. The complete mitochondrial genome of M. grandicella is 15,861 bp in length, which is the first representative from the suborder Malacostegina (Bryozoa), and is relatively larger when compared with mtDNAs of other study bryozoans. The mitochondrial genome contains 13 protein-coding genes, two ribosomal RNAs and 20 transfer RNAs. Compared with other study bryozoans, gene arrangements of five bryozoans mitochondrial genomes are significantly different. Comparison of bryozoans mitochondrial gene arrangements can be important information sources for exploring the phylogenetic relationships within the group.
Traditionally, the mitochondrial genome sequences were usually obtained by shotgun or primers-walking combination with long PCR. The next-generation sequencing technologies are developing fastly in recent years, such as 454, Solexa and SOLiD sequencing platform. Membranipora grandicella complete mitochondrial genome sequence was determined based on next-generation high-throughput sequencing technology (Solexa) and nested PCR amplification. The complete mitochondrial genome of M. grandicella is 15,861 bp in length, which is the first representative from the suborder Malacostegina (Bryozoa), and is relatively larger when compared with mtDNAs of other study bryozoans. The mitochondrial genome contains 13 protein-coding genes, two ribosomal RNAs and 20 transfer RNAs. Compared with other study bryozoans, gene arrangements of five bryozoans mitochondrial genomes are significantly different. Comparison of bryozoans mitochondrial gene arrangements can be important information sources for exploring the phylogenetic relationships within the group.
2012, 34(2): 143-152.
Abstract:
Photosynthetic pigments are routinely used as biomarkers for various phytoplankton taxa in"class"level. Vertical distributions of photosynthetic pigments from 5 stations in the warm pool were studied during China’s DY20 and DY21 cruises in the western equatorial Pacific. Phytoplankton community structure was discussed using pigment signals and the matrix factorization program CHEMTAX. In the nutrients-depleted warm pool, the concentrations of zeaxanthin (Zea) and divinyl chlorophyll a(DV Chl a) were correlated with chlorophyll a concentration,and phytoplankton community was characterized by high contribution of cyanobacteria, prochlorophytes and haptophytes. Besides, cyanobacteria and prochlorophytes occupied different depths of the euphotic zone,and haptophytes was the dominant algae in nutrient enrichment subsurface water.
Photosynthetic pigments are routinely used as biomarkers for various phytoplankton taxa in"class"level. Vertical distributions of photosynthetic pigments from 5 stations in the warm pool were studied during China’s DY20 and DY21 cruises in the western equatorial Pacific. Phytoplankton community structure was discussed using pigment signals and the matrix factorization program CHEMTAX. In the nutrients-depleted warm pool, the concentrations of zeaxanthin (Zea) and divinyl chlorophyll a(DV Chl a) were correlated with chlorophyll a concentration,and phytoplankton community was characterized by high contribution of cyanobacteria, prochlorophytes and haptophytes. Besides, cyanobacteria and prochlorophytes occupied different depths of the euphotic zone,and haptophytes was the dominant algae in nutrient enrichment subsurface water.
2012, 34(2): 153-161.
Abstract:
Changes in growth, cellular DNA, RNA and total protein content related to nitrogen(N) and phosphorus(P) concentrations were studied in a marine dinoflagellate Prorocentrum donghaiense Lugrown in batch cultures. The results show that the growth of P. donghaiense is significantly affected by N and P concentrations. The ultimate biomass depended on the initial N and P concentrations. The maximum growth varied distinctly under different N or P treatments(P<0.05). DNA content had significant correlation with N concentrations in the cultures but not with P. RNA content was strongly associated with both N and P concentrations(P<0.01). Different growth stages could also change cellular RNA content. The RNA content decreased along with the extension of experimental time.RNA/DNA ratio had significant correlation with the N and P concentrations. There appeared to be a linear relationship between the growth rate and the ratio of RNA/DNA. Cellular total protein content was significantly affected by N concentrations. P deficiency could also reduce cellular protein content.
Changes in growth, cellular DNA, RNA and total protein content related to nitrogen(N) and phosphorus(P) concentrations were studied in a marine dinoflagellate Prorocentrum donghaiense Lugrown in batch cultures. The results show that the growth of P. donghaiense is significantly affected by N and P concentrations. The ultimate biomass depended on the initial N and P concentrations. The maximum growth varied distinctly under different N or P treatments(P<0.05). DNA content had significant correlation with N concentrations in the cultures but not with P. RNA content was strongly associated with both N and P concentrations(P<0.01). Different growth stages could also change cellular RNA content. The RNA content decreased along with the extension of experimental time.RNA/DNA ratio had significant correlation with the N and P concentrations. There appeared to be a linear relationship between the growth rate and the ratio of RNA/DNA. Cellular total protein content was significantly affected by N concentrations. P deficiency could also reduce cellular protein content.
2012, 34(2): 162-168.
Abstract:
The effects of DIC levels on the photosynthesis of Ulva prolifera, carbon absorbing capacity at aquatic and aerial state, and pH value improving ability, were studied under laboratory conditions. The results show that the value of Km (DIC) for photosynthesis of U. prolifera is 0.25 mmol/dm3, and photosynthesis of U. prolifera is saturated at 1.2mmol/dm3 of DIC concentration in seawater, which is extremely lower than ambient DIC concentration(2.4 mmol/dm3, DIC) in normal seawater. It indicates that the blades in U. prolifera could keep a vigorous photosynthesis and growth during "green tide" blooming. In seawater, the blades of U. prolifera absorbed the DIC from seawater. Cultured with blade density of 0.5 g/dm3, the rate of carbon fixation of U. prolifera by photosynthesis is 10.92 mg/(g·d)(FW) for one photosynthesis period. Cultured for 5 d, the DIC concentration in 0.5, 1.0 and 2.5 g/dm3 blade density groups decreases to 4.85, 2.62 and 0.66 mg/dm3 respectively. It indicates that DIC uptaking rate increases with the blade density increase, and the DIC concentration removal rate is 77.78%, 88.00% and 96.98% for 0.5, 1.0 and 2.5 g/dm3blade density groups, respectively. When blades absorbed the DIC out of seawater, they immediately increased the pH in seawater, and the rate for pH increasing reached to 0.96 /(dm3·g·d) in culture system with 0.5 g/dm3 blade density during one photosynthesis period. Cultured for 5 d, the pH value in 0.5, 1.0 and 2.5 g/dm3blade density groups increases to 9.1, 9.2 and 9.7 in the first culture day respectively, and keeps at 9.9 in the 5th day. It indicates that the higher the blade density, the higher the pH in culture system.When exposed in air, the blades could absorb the CO2 from air. The rate of photosynthetic carbon fixation of U.prolifera in the air is about 46.14 mg/(g·d) during one photosynthesis period, and it is 4.23 times more than that in water. The photosynthesis carbon fixation efficiency for unit mass would decrease for shading among blades. It indicates that this study will provide the supports for green tide blooming mechanism study and estimating its CO2 emission reduction and ocean acidification prevention.
The effects of DIC levels on the photosynthesis of Ulva prolifera, carbon absorbing capacity at aquatic and aerial state, and pH value improving ability, were studied under laboratory conditions. The results show that the value of Km (DIC) for photosynthesis of U. prolifera is 0.25 mmol/dm3, and photosynthesis of U. prolifera is saturated at 1.2mmol/dm3 of DIC concentration in seawater, which is extremely lower than ambient DIC concentration(2.4 mmol/dm3, DIC) in normal seawater. It indicates that the blades in U. prolifera could keep a vigorous photosynthesis and growth during "green tide" blooming. In seawater, the blades of U. prolifera absorbed the DIC from seawater. Cultured with blade density of 0.5 g/dm3, the rate of carbon fixation of U. prolifera by photosynthesis is 10.92 mg/(g·d)(FW) for one photosynthesis period. Cultured for 5 d, the DIC concentration in 0.5, 1.0 and 2.5 g/dm3 blade density groups decreases to 4.85, 2.62 and 0.66 mg/dm3 respectively. It indicates that DIC uptaking rate increases with the blade density increase, and the DIC concentration removal rate is 77.78%, 88.00% and 96.98% for 0.5, 1.0 and 2.5 g/dm3blade density groups, respectively. When blades absorbed the DIC out of seawater, they immediately increased the pH in seawater, and the rate for pH increasing reached to 0.96 /(dm3·g·d) in culture system with 0.5 g/dm3 blade density during one photosynthesis period. Cultured for 5 d, the pH value in 0.5, 1.0 and 2.5 g/dm3blade density groups increases to 9.1, 9.2 and 9.7 in the first culture day respectively, and keeps at 9.9 in the 5th day. It indicates that the higher the blade density, the higher the pH in culture system.When exposed in air, the blades could absorb the CO2 from air. The rate of photosynthetic carbon fixation of U.prolifera in the air is about 46.14 mg/(g·d) during one photosynthesis period, and it is 4.23 times more than that in water. The photosynthesis carbon fixation efficiency for unit mass would decrease for shading among blades. It indicates that this study will provide the supports for green tide blooming mechanism study and estimating its CO2 emission reduction and ocean acidification prevention.
2012, 34(2): 169-178.
Abstract:
Culture filtrates of Skeletonema costatum were tested to verify the effects of allelopathy on the growth of algae. S. costatum growth was inhibited, especially in P limiting cultures. The filtrates of S. costatum in exponential phase exhibited significantly inhibitory effect on the growth of its own compared with the controls, which was stronger than that of declining phase filtrates, hence, allelopathic effect was connected with the growth phase of algae. The filtrates with different ratios showed different inhibitory degrees to S. costatum itself, and the ratio was higher the inhibition was stronger. In degradation experiments, the dramatic decrease of inhibitory effect on S. costatum was observed. A possible explanation for this might be that allelopathic compounds in S. costatum cultures could be degraded. In addition, during all filtrate experiments, the growth of P. donghaiense was not affected, which might because of the tolerance of P. donghaiense to these allelochemicals in S. costatum filtrates. Furthermore, S. costatum and P. donghaiense were cultivated together in S. costatum filtrates, and the results showed that P. donghaiense couldoutcompete S. costatum in the end. Consequently, allelopathy might have important effect on the competition and succession between S. costatum and P. donghaiense.
Culture filtrates of Skeletonema costatum were tested to verify the effects of allelopathy on the growth of algae. S. costatum growth was inhibited, especially in P limiting cultures. The filtrates of S. costatum in exponential phase exhibited significantly inhibitory effect on the growth of its own compared with the controls, which was stronger than that of declining phase filtrates, hence, allelopathic effect was connected with the growth phase of algae. The filtrates with different ratios showed different inhibitory degrees to S. costatum itself, and the ratio was higher the inhibition was stronger. In degradation experiments, the dramatic decrease of inhibitory effect on S. costatum was observed. A possible explanation for this might be that allelopathic compounds in S. costatum cultures could be degraded. In addition, during all filtrate experiments, the growth of P. donghaiense was not affected, which might because of the tolerance of P. donghaiense to these allelochemicals in S. costatum filtrates. Furthermore, S. costatum and P. donghaiense were cultivated together in S. costatum filtrates, and the results showed that P. donghaiense couldoutcompete S. costatum in the end. Consequently, allelopathy might have important effect on the competition and succession between S. costatum and P. donghaiense.
2012, 34(2): 179-184.
Abstract:
On the basis of chemical anomalies between hydrothermal plumes and surrounding seawater a means of detecting hydrothermal activity is proposed. Therefore, a multiparameter chemical sensor integrating three types of electrochemical electrodes, including Eh, Ag/Ag2S and pH electrodes, is designed to be applied in deep-sea measurements during DY115-20 cruise by Dayang No.1 research vessel. It is proved by the measuring results that the multiparameter chemical sensor can help to detect the chemical anomalies of the plumes. The electrodes exhibit good sensitivity, stability and long lifetime in the multiple applications during six months. Among the 60 measurements in both East Pacific Ridge (EPR) and Southwest Indian Ridge (SWIR), the integrated sensor records 55 groups of valid data, in which 29 records indicate potential active hydrothermal vents, which proves an effective tool in hydrothermal activity detection.
On the basis of chemical anomalies between hydrothermal plumes and surrounding seawater a means of detecting hydrothermal activity is proposed. Therefore, a multiparameter chemical sensor integrating three types of electrochemical electrodes, including Eh, Ag/Ag2S and pH electrodes, is designed to be applied in deep-sea measurements during DY115-20 cruise by Dayang No.1 research vessel. It is proved by the measuring results that the multiparameter chemical sensor can help to detect the chemical anomalies of the plumes. The electrodes exhibit good sensitivity, stability and long lifetime in the multiple applications during six months. Among the 60 measurements in both East Pacific Ridge (EPR) and Southwest Indian Ridge (SWIR), the integrated sensor records 55 groups of valid data, in which 29 records indicate potential active hydrothermal vents, which proves an effective tool in hydrothermal activity detection.
2012, 34(2): 185-191.
Abstract:
Deep-water bottom current research in the northern South China Sea using a reflection seismic method
2012, 34(2): 192-198.
Abstract:
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