2013 Vol. 35, No. 6
Display Method:
2013, 35(6): 1-8.
Abstract:
A spring warm pool appeared before the summer monsoon onset in Bay of Bengal (BOB), and disappeared rapidly after the monsoon onset. The RAMA buoy data in central BOB were used to study seasonal warm pool process by diagnosing the heat budget of mixed layer in BOB. The study showed: The Net surface heat flux dominated both generation and decay phase of the spring warm pool, which performed a strong heating effect in generation phase and a strong cooling effect in decay phase. Advection of temperature only played an important role only in winter time when the entrainment effect became strong during the warming period. Analysis on heat flux term showed: The heating effect of solar radiation was the main determining factor of the behalf of net surface heat flux, which was high to 0.32℃/d in generation phase. The cooling effect of latent heat flux was not varied much, which was about -1.4℃/d all the time. The cooling effect of long wave radiation slowed down the speed of temperature increase in generation phase. The sensible heat flux played a negligible role all the time.
A spring warm pool appeared before the summer monsoon onset in Bay of Bengal (BOB), and disappeared rapidly after the monsoon onset. The RAMA buoy data in central BOB were used to study seasonal warm pool process by diagnosing the heat budget of mixed layer in BOB. The study showed: The Net surface heat flux dominated both generation and decay phase of the spring warm pool, which performed a strong heating effect in generation phase and a strong cooling effect in decay phase. Advection of temperature only played an important role only in winter time when the entrainment effect became strong during the warming period. Analysis on heat flux term showed: The heating effect of solar radiation was the main determining factor of the behalf of net surface heat flux, which was high to 0.32℃/d in generation phase. The cooling effect of latent heat flux was not varied much, which was about -1.4℃/d all the time. The cooling effect of long wave radiation slowed down the speed of temperature increase in generation phase. The sensible heat flux played a negligible role all the time.
2013, 35(6): 9-20.
Abstract:
Based on SODA ocean assimilation and NCEP atmospheric reanalysis data, relationships of the main modes of tropic Pacific subsurface ocean temperature anomalies with variations of the upper ocean circulation of the North Pacific low-latitude western boundary currents (NPLLWBC) and the Asian-North Pacific atmospheric vertical and horizontal flow fields are analyzed. Major results are summarized as follows:(1) The tropical Pacific subsurface ocean variabilities are dominated by two primary modes, which make up the ENSO cycle. The first mode, represents the ENSO mature phase, and mainly prevails in winter, while the second mode represents the ENSO transition phase, prevailing in summer.(2) ENSO cycle has major impact on the upper ocean circulation in the NPLLWBC areas. During the developing phase of El Niño events or decaying phase of La Niña events, anomalous cyclonic circulation evolves in this area, accompanied by strengthening of the North Equatorial Current (NEC), northward shift of the NEC bifurcation location, enhancement of the Mindanao Current (MC), weakening of the Kuroshio Current (KC) in its source region, and the strongest phase of the North Equatorial Countercurrent (NECC). During the mature phase of El Niño, the anomalous cyclonic circulation in this area reaches its strongest phase, with NEC also strongest, NEC bifurcation location northmost, MC strongest, KC weakest, and NECC weakened. Vice versa, during the decaying of El Niño or developing of La Niña, anomalous anti-cyclonic circulation appears in the area, the NEC weakens, NEC bifurcation location shifts southward, MC weakens while KC strengthens, and the NECC becomes weakest. During the mature phase of La Niña, the anti-cyclonic circulation anomalies become strongest, with NEC weakest, NEC bifurcation location southmost, MC weakest, KC strongest, and NECC strengthened. (3) The influence of ENSO cycle on the upper ocean circulation of NPLLWBC are mainly achieved through the change of atmospheric circulation in response to thermal condition anomalies in the tropical Pacific during ENSO events. The ENSO events first generate anomalous thermal conditions in the tropical Pacific Ocean, which lead to anomalous convection activities in the above atmosphere. The latter in turn alters atmospheric circulation field in related area directly or indirectly by energy transport through the "atmospheric bridge" resulting in anomalous sea surface wind stress fields, and thus forces corresponding variations in the upper ocean circulation. In the end of the paper, the reasons for generation and sustainment of the anomalous anti-cyclonic/cyclonic wind fields near Philippines during the ENSO events are also analyzed, and the contributions of air-sea interaction in the NPLLWBC areas to the ENSO cycle are discussed.
Based on SODA ocean assimilation and NCEP atmospheric reanalysis data, relationships of the main modes of tropic Pacific subsurface ocean temperature anomalies with variations of the upper ocean circulation of the North Pacific low-latitude western boundary currents (NPLLWBC) and the Asian-North Pacific atmospheric vertical and horizontal flow fields are analyzed. Major results are summarized as follows:(1) The tropical Pacific subsurface ocean variabilities are dominated by two primary modes, which make up the ENSO cycle. The first mode, represents the ENSO mature phase, and mainly prevails in winter, while the second mode represents the ENSO transition phase, prevailing in summer.(2) ENSO cycle has major impact on the upper ocean circulation in the NPLLWBC areas. During the developing phase of El Niño events or decaying phase of La Niña events, anomalous cyclonic circulation evolves in this area, accompanied by strengthening of the North Equatorial Current (NEC), northward shift of the NEC bifurcation location, enhancement of the Mindanao Current (MC), weakening of the Kuroshio Current (KC) in its source region, and the strongest phase of the North Equatorial Countercurrent (NECC). During the mature phase of El Niño, the anomalous cyclonic circulation in this area reaches its strongest phase, with NEC also strongest, NEC bifurcation location northmost, MC strongest, KC weakest, and NECC weakened. Vice versa, during the decaying of El Niño or developing of La Niña, anomalous anti-cyclonic circulation appears in the area, the NEC weakens, NEC bifurcation location shifts southward, MC weakens while KC strengthens, and the NECC becomes weakest. During the mature phase of La Niña, the anti-cyclonic circulation anomalies become strongest, with NEC weakest, NEC bifurcation location southmost, MC weakest, KC strongest, and NECC strengthened. (3) The influence of ENSO cycle on the upper ocean circulation of NPLLWBC are mainly achieved through the change of atmospheric circulation in response to thermal condition anomalies in the tropical Pacific during ENSO events. The ENSO events first generate anomalous thermal conditions in the tropical Pacific Ocean, which lead to anomalous convection activities in the above atmosphere. The latter in turn alters atmospheric circulation field in related area directly or indirectly by energy transport through the "atmospheric bridge" resulting in anomalous sea surface wind stress fields, and thus forces corresponding variations in the upper ocean circulation. In the end of the paper, the reasons for generation and sustainment of the anomalous anti-cyclonic/cyclonic wind fields near Philippines during the ENSO events are also analyzed, and the contributions of air-sea interaction in the NPLLWBC areas to the ENSO cycle are discussed.
2013, 35(6): 21-30.
Abstract:
Based on the statistical analysis,the western Pacific subtropical high (WPSH) has remarkable interannual and interdecadal variations. The area and the intensity of WPSH have obvious 3-4 a and 11-14 a periods, while the western ridge point has 3-5 a and quasi-13 a periods. The variations of the area of WPSH are similar with the intensity. Both of them have a strong positive correlation with the Sea Surface Temperature (SST) in the central and eastern equatorial Pacific, negative correlation with the variation of the western ridge point. There are significant differences between the variations of SST anomalies at different longitude of the equatorial Pacific and the variations of WPSH. The variations of SST anomalies in the central equatorial Pacific have a close relationship with the variation of WPSH and it is not consanguineous between the SST anomalies in the eastern equatorial Pacific and variations of WPSH. But the variations of SST anomalies in the western Pacific have a negative relationship with the variations of WPSH. So the SST anomalies in the central equatorial Pacific are a key factor for the variations of the WPSH. Based on the close relationship between them, a regression equation is obtained to predict the variations of the intensity and the western ridge point of WPSH in 2013, providing a reference for the flood season precipitation in 2013.
Based on the statistical analysis,the western Pacific subtropical high (WPSH) has remarkable interannual and interdecadal variations. The area and the intensity of WPSH have obvious 3-4 a and 11-14 a periods, while the western ridge point has 3-5 a and quasi-13 a periods. The variations of the area of WPSH are similar with the intensity. Both of them have a strong positive correlation with the Sea Surface Temperature (SST) in the central and eastern equatorial Pacific, negative correlation with the variation of the western ridge point. There are significant differences between the variations of SST anomalies at different longitude of the equatorial Pacific and the variations of WPSH. The variations of SST anomalies in the central equatorial Pacific have a close relationship with the variation of WPSH and it is not consanguineous between the SST anomalies in the eastern equatorial Pacific and variations of WPSH. But the variations of SST anomalies in the western Pacific have a negative relationship with the variations of WPSH. So the SST anomalies in the central equatorial Pacific are a key factor for the variations of the WPSH. Based on the close relationship between them, a regression equation is obtained to predict the variations of the intensity and the western ridge point of WPSH in 2013, providing a reference for the flood season precipitation in 2013.
2013, 35(6): 31-42.
Abstract:
This paper is mainly focused on the continental coastline changes of China in the span of 1980-2010. Remote sensing images of Landsat MSS, TM and ETM+in the year of 1980, 1990, 2000 and 2010 are processed to extract coastlines and land use in the gap of coastline changes. Based on the technology of RS and GIS, the spatial and temporal changes of coastline are analyzed, the result show that: (1) the coastline type changes significantly, the length of artificial coastline in 1980, 1990, 2000, and 2010 occupies 24%, 39.3%,49.4%and 56.1%, respectively; (2) the coastline change shows a significant regional characteristic, coastline changed significantly in the coast segment of the Zhujiang Estuary, the Changjiang Estuary to the Hangzhou Bay, the Lvsi Port to the Haizhou Bay, the Weihe to the Luan Estuaries and the Liaohe Estuary to the Huludao Port; (3) comparing the three sub periods of the research span, a coastal reclamation is mainly focuses on an urban construction and a maritime transport in the later period while focuses on aquiculture in the earlier period; from the north to the south, the changes of continental coastline of China show significant temporal and spatial heterogeneity.
This paper is mainly focused on the continental coastline changes of China in the span of 1980-2010. Remote sensing images of Landsat MSS, TM and ETM+in the year of 1980, 1990, 2000 and 2010 are processed to extract coastlines and land use in the gap of coastline changes. Based on the technology of RS and GIS, the spatial and temporal changes of coastline are analyzed, the result show that: (1) the coastline type changes significantly, the length of artificial coastline in 1980, 1990, 2000, and 2010 occupies 24%, 39.3%,49.4%and 56.1%, respectively; (2) the coastline change shows a significant regional characteristic, coastline changed significantly in the coast segment of the Zhujiang Estuary, the Changjiang Estuary to the Hangzhou Bay, the Lvsi Port to the Haizhou Bay, the Weihe to the Luan Estuaries and the Liaohe Estuary to the Huludao Port; (3) comparing the three sub periods of the research span, a coastal reclamation is mainly focuses on an urban construction and a maritime transport in the later period while focuses on aquiculture in the earlier period; from the north to the south, the changes of continental coastline of China show significant temporal and spatial heterogeneity.
2013, 35(6): 43-53.
Abstract:
A suspended sediment concentration(SSC) is retrieved from the Landsat images during 1986-2004 in the Laizhou Bay of Shandong Province, China using the model that is established according to the field measurement data off the Huanghe River mouth. The transportation, distribution and deposition of the suspended sediment are estimated in the Laizhou Bay. The relationships between the distribution of suspended sediment and the change of submarine topography and ocean dynamic are also discussed, the combination of hydrological and meteorological data, depth measurement data and the numerical simulation results of extreme weather in the southwest area of the Laizhou Bay. The results show that the zone of turbidity maximum is inferred in the Huanghe River mouth and near the southwest shore of the Laizhou Bay, and the turbid water during low discharge period covers a much larger area than in the flood season. Ahigher current velocity field off the Huanghe River mouth is companied usually with the higher magnitude of the SSC. The suspended sediment mainly originates from river discharge and resuspension near the Huanghe River mouth. However, the zone of turbidity maximum near the southwest shore primarily caused by the resuspension of the bottom surface sediments induced by tidal currents. The water/sediment discharge from the Huanghe River controlls the magnitude of the SSC, and the distribution of SSC caused by wind and spring-neap tidal cycle is usually smaller than the SSC variations caused by tidal current fields. In the extreme weather condition, the SSC increases significantly in the shallow coastal areas of the southwest Laizhou Bay.
A suspended sediment concentration(SSC) is retrieved from the Landsat images during 1986-2004 in the Laizhou Bay of Shandong Province, China using the model that is established according to the field measurement data off the Huanghe River mouth. The transportation, distribution and deposition of the suspended sediment are estimated in the Laizhou Bay. The relationships between the distribution of suspended sediment and the change of submarine topography and ocean dynamic are also discussed, the combination of hydrological and meteorological data, depth measurement data and the numerical simulation results of extreme weather in the southwest area of the Laizhou Bay. The results show that the zone of turbidity maximum is inferred in the Huanghe River mouth and near the southwest shore of the Laizhou Bay, and the turbid water during low discharge period covers a much larger area than in the flood season. Ahigher current velocity field off the Huanghe River mouth is companied usually with the higher magnitude of the SSC. The suspended sediment mainly originates from river discharge and resuspension near the Huanghe River mouth. However, the zone of turbidity maximum near the southwest shore primarily caused by the resuspension of the bottom surface sediments induced by tidal currents. The water/sediment discharge from the Huanghe River controlls the magnitude of the SSC, and the distribution of SSC caused by wind and spring-neap tidal cycle is usually smaller than the SSC variations caused by tidal current fields. In the extreme weather condition, the SSC increases significantly in the shallow coastal areas of the southwest Laizhou Bay.
2013, 35(6): 54-66.
Abstract:
Water samples and Conductance, Temperature, Depth (CTD) data have been collected through the Public Cruise of the National Research Foundation Committee, in October, 2010.After filtering of the water samples, the total suspended matter (TSM) has been obtained.The concentration of the main and trace elements of TSM has been tested using ICP-AES and ICP-MS, meanwhile an elementary composition, a spacial distribution as well as their influencing factors had also been studied.The results show that the value of main elements (aluminium, magnesium, ion, calcium) concentration between 1% and 30% and aluminium is the highest; the values of the trace elements(cadmium, chromium, cobalt, copper, manganese, nickel, lead, vanadium) concentration are between n×10-6 and n×10-9 and manganese is the highest.The good relationships among aluminium, ion, magnesium and most trace elements indicate that the main elements are terrigenous and the trace elements are adsorbed on the land-based suspended particles.The water masses play an important role in the elementary composition of TSM, especially aluminium, ion and chromium, cobalt, copper, manganese, nickel, vanadium.
Water samples and Conductance, Temperature, Depth (CTD) data have been collected through the Public Cruise of the National Research Foundation Committee, in October, 2010.After filtering of the water samples, the total suspended matter (TSM) has been obtained.The concentration of the main and trace elements of TSM has been tested using ICP-AES and ICP-MS, meanwhile an elementary composition, a spacial distribution as well as their influencing factors had also been studied.The results show that the value of main elements (aluminium, magnesium, ion, calcium) concentration between 1% and 30% and aluminium is the highest; the values of the trace elements(cadmium, chromium, cobalt, copper, manganese, nickel, lead, vanadium) concentration are between n×10-6 and n×10-9 and manganese is the highest.The good relationships among aluminium, ion, magnesium and most trace elements indicate that the main elements are terrigenous and the trace elements are adsorbed on the land-based suspended particles.The water masses play an important role in the elementary composition of TSM, especially aluminium, ion and chromium, cobalt, copper, manganese, nickel, vanadium.
2013, 35(6): 67-74.
Abstract:
The age model of Core BR07 is reconstructed based on the comparisons of diatom distributions and color parameters of the sediments between Cores B5-4 and BR07, both collected from the northern continental slope of the Bering Sea. According to this age model, the deposition ages of Core BR07 range from 1.9 to 11.3 kaBP, with an average sedimentation rate of 28.5 cm/ka which is slightly lower than that of Core B5-4. A sea-ice proxy, defined as the ratio of Fragilariopsis cylindrus content to (F. cylindrus content+Neodenticula seminae content), is proposed to reconstruct the historic climate record of sea-ice changes over the last 10 ka. Three cold events (including the Younger Dryas cold event) as well as one warm event since the last deglacial period have been detected in the core. The reconstructed time span of the Younger Dryas cold event in Core BR07 is 11.3~10.7 ka BP, close to its correspondent of 12.9~11.6 ka BP from Greenland ice cores, further confirming that it is more reliable than the age generated from the radiocarbon dating of the bulk sediment organic carbon.
The age model of Core BR07 is reconstructed based on the comparisons of diatom distributions and color parameters of the sediments between Cores B5-4 and BR07, both collected from the northern continental slope of the Bering Sea. According to this age model, the deposition ages of Core BR07 range from 1.9 to 11.3 kaBP, with an average sedimentation rate of 28.5 cm/ka which is slightly lower than that of Core B5-4. A sea-ice proxy, defined as the ratio of Fragilariopsis cylindrus content to (F. cylindrus content+Neodenticula seminae content), is proposed to reconstruct the historic climate record of sea-ice changes over the last 10 ka. Three cold events (including the Younger Dryas cold event) as well as one warm event since the last deglacial period have been detected in the core. The reconstructed time span of the Younger Dryas cold event in Core BR07 is 11.3~10.7 ka BP, close to its correspondent of 12.9~11.6 ka BP from Greenland ice cores, further confirming that it is more reliable than the age generated from the radiocarbon dating of the bulk sediment organic carbon.
2013, 35(6): 75-85.
Abstract:
The lipid biomarkers of fatty acids in the surface sediments from Shenhu Area,northern South China Sea continental slope were investigated in the present paper. The total contents of the fatty acid from the sediments amounts to 5.14 ~ 8.99 μg/g,and its carbon number ranges from C12 to C32. The fatty acid includes 48 types such as the saturated fatty acid,branched fatty acid,monounsaturated fatty acid,polyunsaturated fatty acid and isoprenoid acid. In these five samples,the short chain saturated fatty acid mainly came from bacteria and planktons,while the long chain saturated fatty acid was from the terrigenous higher plants. Their ratio indicates that the input of marine bacteria and planktons is far more than that of the terrigenous higher plant in the studied area. The branched fatty acid 10me16:0 and monounsaturated fatty acid 18:1ω9、16:1ω9 are mainly synthesized by the sulfate reducing bacteria,while 16:1ω7 is from the sulfur oxidizing bacteria. Comparison of the relative content of them,the author believes that the surface sediments of the Shenhu area may be embraced by reducing environment. In addition,eight isoprenoid acids detected in the samples,mainly phytanic acid and 17β(H),21β(H)-32-hopanoic acid,and a small amount of the pristane acid,presumably for the joint contribution of chlorophyll A and bacterial microorganisms.
The lipid biomarkers of fatty acids in the surface sediments from Shenhu Area,northern South China Sea continental slope were investigated in the present paper. The total contents of the fatty acid from the sediments amounts to 5.14 ~ 8.99 μg/g,and its carbon number ranges from C12 to C32. The fatty acid includes 48 types such as the saturated fatty acid,branched fatty acid,monounsaturated fatty acid,polyunsaturated fatty acid and isoprenoid acid. In these five samples,the short chain saturated fatty acid mainly came from bacteria and planktons,while the long chain saturated fatty acid was from the terrigenous higher plants. Their ratio indicates that the input of marine bacteria and planktons is far more than that of the terrigenous higher plant in the studied area. The branched fatty acid 10me16:0 and monounsaturated fatty acid 18:1ω9、16:1ω9 are mainly synthesized by the sulfate reducing bacteria,while 16:1ω7 is from the sulfur oxidizing bacteria. Comparison of the relative content of them,the author believes that the surface sediments of the Shenhu area may be embraced by reducing environment. In addition,eight isoprenoid acids detected in the samples,mainly phytanic acid and 17β(H),21β(H)-32-hopanoic acid,and a small amount of the pristane acid,presumably for the joint contribution of chlorophyll A and bacterial microorganisms.
2013, 35(6): 86-95.
Abstract:
Based on Core C0702 in the East China Sea mud area, an elemental analysis quality was appraised by comparing the results of two analysis methods, which are an X-ray fluorescence core scanner (X-ray core scanner) and an X-ray fluorescence spectrometer (XRF). The results show that: (1) The elements detected by the X-ray core scanner can be divided into four classes. Elements in Class Ⅰ show a high detecting quality, and the intensities of these elemente measured by the X-ray core scanner can be taken as contents directly. The measuring intensities of elements in Class Ⅱ are great significance, and those in Class Ⅲ are small significance. However,the measured intensities of elements in Class Ⅳ are worthless and minor significant. (2) The analysis results of element itensities in marine sediments detected by the X-ray core scanner affected by compaction, especially, Ca,Fe,K,Ti,Si are more vulnerable. A formula for eliminating this effect via calibration is proposed. (3) The measuring results of Ca,Fe,K,Si,Ti detected by the two methods show a good linear relationship (with correlation coefficients of 0.46-0.87), so the element intensities of Ca,Fe,K,Si,Ti detected by the X-ray core scanner could be converted into the chemical content according to the relationship.
Based on Core C0702 in the East China Sea mud area, an elemental analysis quality was appraised by comparing the results of two analysis methods, which are an X-ray fluorescence core scanner (X-ray core scanner) and an X-ray fluorescence spectrometer (XRF). The results show that: (1) The elements detected by the X-ray core scanner can be divided into four classes. Elements in Class Ⅰ show a high detecting quality, and the intensities of these elemente measured by the X-ray core scanner can be taken as contents directly. The measuring intensities of elements in Class Ⅱ are great significance, and those in Class Ⅲ are small significance. However,the measured intensities of elements in Class Ⅳ are worthless and minor significant. (2) The analysis results of element itensities in marine sediments detected by the X-ray core scanner affected by compaction, especially, Ca,Fe,K,Ti,Si are more vulnerable. A formula for eliminating this effect via calibration is proposed. (3) The measuring results of Ca,Fe,K,Si,Ti detected by the two methods show a good linear relationship (with correlation coefficients of 0.46-0.87), so the element intensities of Ca,Fe,K,Si,Ti detected by the X-ray core scanner could be converted into the chemical content according to the relationship.
2013, 35(6): 96-112.
Abstract:
Benthic foraminiferal assemblages in 139 western Arctic surface sediment samples recovered during the CHINARE Ⅰ~Ⅳ cruises were studied.The relative abundances of each species were calculated and according to the spatial distribution pattern of dominant species, benthic foraminiferal assemblages were divided to determine the relationship between the assemblage and environmental parameters.Our results show that the spatial distribution pattern of low benthic foraminiferal abundance in the Chukchi shelf area is controlled by high terrigenous matter input.In Chukchi Plateau and Alpha ridge, high benthic foraminiferal abundance is influenced by the warm and saline intermediate Atlantic water.In the Mendeleev Abyssal Plain and Canadian Basin, low benthic foraminiferal abundance is influenced by calcium carbonate dissolution and the appearance of porcelain-like species Pyrgo williamsoni and Quinqueloculina orientalis at 3 597 m sites indicates the carbonate compensate depth (CCD) is greater than 3 600 m.Five assemblages related to spatial environmental factors can be determined by 7 dominant species: Southern Chukchi shelf-Bering Strait assemblage is dominantly characterized by Elphidium excavatum and Buccella frigida, representing the influence of shallow Bering Sea Shelf Water; Alaska Coast-Beaufort Sea assemblage is dominantly characterized by Florilus scaphus-Elphidium albiumbilicatum, indicating the low salinity environment due to seasonal sea ice melting and/or Alaska Coastal Current or riverine input; Atlantic Intermediate Water assemblage is dominated by Cassidulina laevigata, representing warm saline Atlantic Intermediate Water; Arctic Deep Water assemblage is dominated by Cibicides wuellerstorfi, reflecting the low temperature and high salinity environment greater than 1 500 m; Mendeleev Abyssal Plain assemblage is dominated by Oridorsalis umbonatus, showing the oligotrophic bottom water environment.
Benthic foraminiferal assemblages in 139 western Arctic surface sediment samples recovered during the CHINARE Ⅰ~Ⅳ cruises were studied.The relative abundances of each species were calculated and according to the spatial distribution pattern of dominant species, benthic foraminiferal assemblages were divided to determine the relationship between the assemblage and environmental parameters.Our results show that the spatial distribution pattern of low benthic foraminiferal abundance in the Chukchi shelf area is controlled by high terrigenous matter input.In Chukchi Plateau and Alpha ridge, high benthic foraminiferal abundance is influenced by the warm and saline intermediate Atlantic water.In the Mendeleev Abyssal Plain and Canadian Basin, low benthic foraminiferal abundance is influenced by calcium carbonate dissolution and the appearance of porcelain-like species Pyrgo williamsoni and Quinqueloculina orientalis at 3 597 m sites indicates the carbonate compensate depth (CCD) is greater than 3 600 m.Five assemblages related to spatial environmental factors can be determined by 7 dominant species: Southern Chukchi shelf-Bering Strait assemblage is dominantly characterized by Elphidium excavatum and Buccella frigida, representing the influence of shallow Bering Sea Shelf Water; Alaska Coast-Beaufort Sea assemblage is dominantly characterized by Florilus scaphus-Elphidium albiumbilicatum, indicating the low salinity environment due to seasonal sea ice melting and/or Alaska Coastal Current or riverine input; Atlantic Intermediate Water assemblage is dominated by Cassidulina laevigata, representing warm saline Atlantic Intermediate Water; Arctic Deep Water assemblage is dominated by Cibicides wuellerstorfi, reflecting the low temperature and high salinity environment greater than 1 500 m; Mendeleev Abyssal Plain assemblage is dominated by Oridorsalis umbonatus, showing the oligotrophic bottom water environment.
2013, 35(6): 113-120.
Abstract:
As an "ecological engineer", Spartina alterniflora was introduced to China from North Carolina, Georgia and Florida, in 1979,and transplanted firstly in the Luoyuan Bay, Fujian Province, China. To explore the expanding process of S. alterniflora, their characteristics of distribution were analyzed using the remote sensing data of 1989-2010 and field investigations as well. The results show that the expanding process of S. alterniflora on the tidal flat can be divided into three phases: the first phase of 1989-1994, where it expands along the high tidal zone; the second phase of 1995-2000, the coverage of S. alterniflora increases rapidly in the middle tidal zone; the last 10 a of 2000-2010, it expands slowly obviously, and the gaps area within populations is covered gradually by the vegetation. In the Louyuan Bay, the total area of S. alterniflora reached approximately 741.13 hm2 up to 2010. The expanding rate of S. alterniflora along the high tidal zone that is parallel to coastal line is higher greatly than that in the area perpendicular to the coastal line; meanwhile the S. alterniflora exhibits different diffusion characteristics in different areas resulted from the impact of the tidal flow and particle deposition. During their quick diffusion, S. alterniflora appears to be distributed along the sides of tidal channels, which may be related to the tidal flow into the tidal channels and the friction effect from sediment boundary. In comparison, the expanding rate of the S. alterniflora is slow in shallow depressions, where is covered gradually by the plant with the deposition of sediments. It is the inhibition effect of tidal flow and trapping effect of the fine particle form S. alterniflora that makes an appearance of a special zone with a weak tidal flow between patches of the S. alterniflora population. This area is a prevail zone for the potential spread of S. alterniflora in the future.
As an "ecological engineer", Spartina alterniflora was introduced to China from North Carolina, Georgia and Florida, in 1979,and transplanted firstly in the Luoyuan Bay, Fujian Province, China. To explore the expanding process of S. alterniflora, their characteristics of distribution were analyzed using the remote sensing data of 1989-2010 and field investigations as well. The results show that the expanding process of S. alterniflora on the tidal flat can be divided into three phases: the first phase of 1989-1994, where it expands along the high tidal zone; the second phase of 1995-2000, the coverage of S. alterniflora increases rapidly in the middle tidal zone; the last 10 a of 2000-2010, it expands slowly obviously, and the gaps area within populations is covered gradually by the vegetation. In the Louyuan Bay, the total area of S. alterniflora reached approximately 741.13 hm2 up to 2010. The expanding rate of S. alterniflora along the high tidal zone that is parallel to coastal line is higher greatly than that in the area perpendicular to the coastal line; meanwhile the S. alterniflora exhibits different diffusion characteristics in different areas resulted from the impact of the tidal flow and particle deposition. During their quick diffusion, S. alterniflora appears to be distributed along the sides of tidal channels, which may be related to the tidal flow into the tidal channels and the friction effect from sediment boundary. In comparison, the expanding rate of the S. alterniflora is slow in shallow depressions, where is covered gradually by the plant with the deposition of sediments. It is the inhibition effect of tidal flow and trapping effect of the fine particle form S. alterniflora that makes an appearance of a special zone with a weak tidal flow between patches of the S. alterniflora population. This area is a prevail zone for the potential spread of S. alterniflora in the future.
2013, 35(6): 121-127.
Abstract:
The polymorphism of CTSL gene in 379 Litopenaeus vannamei was detected using PCR-SSCP technique and its correlations with growth traits of L.vannamei was analyzed by least square method in this study. In addition, differential mRNA expressions of CTSL were carried out by real-time quantitative PCR. The results showed that the product amplified by primer C6 (F/R) displayed polymorphisms containing three genotypes: CC, CT and TT. Compared with the CC genotype, a silence mutation (C→T) occurred in TT genotype in exon6(92 bp)of the CTSL gene. For body mass, body length, the first abdominal segment length, and the last abdominal segment length, shrimps of CC and CT genotypes were significantly higher than those of the TT genotype(p<0.05), while for carapace length and carapace width, shrimps of CC genotype were significantly higher than those of CT and TT(p<0.05). The expressions of CTSL mRNA in various tissues, muscle tissues of different sex, different body weight individuals were: hepatopancreas>stomach>eyestalk>heart>digestive gland, female>male and heavy>light, respectively. The results obtained in this study suggest CTSL gene may be one of the candidates which significantly affect the growth of Litopenaeus vannamei. It can be used as the molecular genetic marker applying for Litopenaeus vannamei breeding. The distribution of the CTSL mRNA may be related to its specific functions in different tissues and its positive roles in the regulation of the shrimp muscle growth.
The polymorphism of CTSL gene in 379 Litopenaeus vannamei was detected using PCR-SSCP technique and its correlations with growth traits of L.vannamei was analyzed by least square method in this study. In addition, differential mRNA expressions of CTSL were carried out by real-time quantitative PCR. The results showed that the product amplified by primer C6 (F/R) displayed polymorphisms containing three genotypes: CC, CT and TT. Compared with the CC genotype, a silence mutation (C→T) occurred in TT genotype in exon6(92 bp)of the CTSL gene. For body mass, body length, the first abdominal segment length, and the last abdominal segment length, shrimps of CC and CT genotypes were significantly higher than those of the TT genotype(p<0.05), while for carapace length and carapace width, shrimps of CC genotype were significantly higher than those of CT and TT(p<0.05). The expressions of CTSL mRNA in various tissues, muscle tissues of different sex, different body weight individuals were: hepatopancreas>stomach>eyestalk>heart>digestive gland, female>male and heavy>light, respectively. The results obtained in this study suggest CTSL gene may be one of the candidates which significantly affect the growth of Litopenaeus vannamei. It can be used as the molecular genetic marker applying for Litopenaeus vannamei breeding. The distribution of the CTSL mRNA may be related to its specific functions in different tissues and its positive roles in the regulation of the shrimp muscle growth.
2013, 35(6): 128-139.
Abstract:
Investigations were made on the macrobenthos diversity in Yellow River Estuary during spring of 2004-2009. A total of 153 macrobenthos species were collected, the range of biomass was 6.31~13.20 g/m2, and the range of density was 44~902 ind./m2.The composition of dominant species was not relatively stable, while higher frequency dominant species were Lineus sp., Glycinde gurjanovae Uschakov et Wu, Iphinoe tenera Lomakina, Raphidopus ciliatus Stimpson. Shannon-Wiener index and Margalef index showed a downward trend during Investigations. The hierarchical clustering of between groups linkage showed that the macrobenthos community could be divided into the near coast and off coast groups. Water deepth,median particle size and salinity were the main environmental factors affecting the macrobenthos communities by RDA analysis.
Investigations were made on the macrobenthos diversity in Yellow River Estuary during spring of 2004-2009. A total of 153 macrobenthos species were collected, the range of biomass was 6.31~13.20 g/m2, and the range of density was 44~902 ind./m2.The composition of dominant species was not relatively stable, while higher frequency dominant species were Lineus sp., Glycinde gurjanovae Uschakov et Wu, Iphinoe tenera Lomakina, Raphidopus ciliatus Stimpson. Shannon-Wiener index and Margalef index showed a downward trend during Investigations. The hierarchical clustering of between groups linkage showed that the macrobenthos community could be divided into the near coast and off coast groups. Water deepth,median particle size and salinity were the main environmental factors affecting the macrobenthos communities by RDA analysis.
2013, 35(6): 140-146.
Abstract:
In recent years,the rise of the jellyfish pond culture covers the decrease of the traditional jellyfish fisheries production in China. And jellyfish pond cultures develop rapidly with high profits. Aurelia aurita is one of the most common jellyfish bloom species which usually occurs in the culture ponds of edible jellyfish Rhopilema esculentum and causes huge losses. However,there is little research about the interspecific competition between A. aurita and R. esculentum. In this paper,a preliminary study was finished about the short-term survival and competitive relationship among the scyphistomae,ephyrae and larvae of A. aurita and R. esculentum. The results are as follows: Only the ephyraes of A. aurita can be eaten by the scyphistomae of R. esculentum,but the ephyrae and larvae of A. aurita can not be harmed by the ephyrae or larvae of R. esculentum. On the contrary,the scyphistomae or larvae of A. aurita were harmful to the scyphistomae,ephyrae and larvae of R. esculentum. Especially the ephyrae of R. esculentum could be seriously injured. When there were shortages of food,all the ephyrae of R. esculentum were eaten. With the growth of jellyfish larvae,they gradually increase resistance to the preying pressure from predators. During the scyphistomae,ephyrae and larvae stages,A. aurita is absolutely superior to R. esculentum. In other words,it could be an important reason that A. aurita often bloomed in many sea areas and culture ponds. In the process of edible jellyfish R. esculentum culturing and seedling raising,the scyphistomae,ephyrae and larvae of A. aurita should not be mixed,in order to avoid the production losses of edible jellyfish.
In recent years,the rise of the jellyfish pond culture covers the decrease of the traditional jellyfish fisheries production in China. And jellyfish pond cultures develop rapidly with high profits. Aurelia aurita is one of the most common jellyfish bloom species which usually occurs in the culture ponds of edible jellyfish Rhopilema esculentum and causes huge losses. However,there is little research about the interspecific competition between A. aurita and R. esculentum. In this paper,a preliminary study was finished about the short-term survival and competitive relationship among the scyphistomae,ephyrae and larvae of A. aurita and R. esculentum. The results are as follows: Only the ephyraes of A. aurita can be eaten by the scyphistomae of R. esculentum,but the ephyrae and larvae of A. aurita can not be harmed by the ephyrae or larvae of R. esculentum. On the contrary,the scyphistomae or larvae of A. aurita were harmful to the scyphistomae,ephyrae and larvae of R. esculentum. Especially the ephyrae of R. esculentum could be seriously injured. When there were shortages of food,all the ephyrae of R. esculentum were eaten. With the growth of jellyfish larvae,they gradually increase resistance to the preying pressure from predators. During the scyphistomae,ephyrae and larvae stages,A. aurita is absolutely superior to R. esculentum. In other words,it could be an important reason that A. aurita often bloomed in many sea areas and culture ponds. In the process of edible jellyfish R. esculentum culturing and seedling raising,the scyphistomae,ephyrae and larvae of A. aurita should not be mixed,in order to avoid the production losses of edible jellyfish.
2013, 35(6): 147-153.
Abstract:
The annual oxygen consumption rate and ammonia excretion rate of three species of bivalve in Zhejiang province were investigated from May 2005 to March 2006. The results showed oxygen consumption rates of Tegillarca granosa, Sinonovacula constricta and Saccostrea cucullata ranged from 0.11 mg/(g·h) to 5.05 mg/(g·h), from 0.77 mg/(g·h) to 5.97 mg/(g·h) and from 0.33 mg/(g·h) to 5.47 mg/(g·h),ammonia excretion rate of three shellfish ranged from 21.51 μg/(g·h) to 1 078.63 μg/(g·h), from 26.97 μg/(g·h) to 990.73 μg/(g·h) and from 32.12 μg/(g·h) to 1 378.67 μg/(g·h). The oxygen consumption and ammonia excretion rate changed greatly in different months (p<0.01), the greatest was in September and the lowest was in January. The results of Paired-Sample Test showed that there were significant differences of oxygen consumption rate between Sinonovacula constricta(SC) and Saccostrea cucullata(SCA), the value of T(SC-SCA) was 3.184(p=0.024), while there were no differences between Tegillarca granosa(TG) and Sinonovacula constricta(SC) (T(TG-SC)=1.887, p=0.118) or between Tegillarca granosa and Saccostrea cucullata(SCA) (T(TG-SCA)=0.246, p=0.815). There were no differences of ammonia excretion rate among three shellfish (T(TG-SC)=0.977, p=0.373; T(TG-SCA)=2.369, p=0.064; T(SC-SCA)=1.002, p=0.362). The relationships between temperature (T) and oxygen consumption or ammonia excretion rate (Y) of three shellfish were described as lnY=lna+blnT(Y=aebT). To maintain their standard metabolism, Saccostrea cucullata consumed more protein for the O/N ratio ranging from 3.04 to 10.27, Tegillarca granosa and Sinonovacula constricta consumed both protein and lipids for the O/N ratio ranging from 4.69 to 28.55 and from 4.68 to 37.89.
The annual oxygen consumption rate and ammonia excretion rate of three species of bivalve in Zhejiang province were investigated from May 2005 to March 2006. The results showed oxygen consumption rates of Tegillarca granosa, Sinonovacula constricta and Saccostrea cucullata ranged from 0.11 mg/(g·h) to 5.05 mg/(g·h), from 0.77 mg/(g·h) to 5.97 mg/(g·h) and from 0.33 mg/(g·h) to 5.47 mg/(g·h),ammonia excretion rate of three shellfish ranged from 21.51 μg/(g·h) to 1 078.63 μg/(g·h), from 26.97 μg/(g·h) to 990.73 μg/(g·h) and from 32.12 μg/(g·h) to 1 378.67 μg/(g·h). The oxygen consumption and ammonia excretion rate changed greatly in different months (p<0.01), the greatest was in September and the lowest was in January. The results of Paired-Sample Test showed that there were significant differences of oxygen consumption rate between Sinonovacula constricta(SC) and Saccostrea cucullata(SCA), the value of T(SC-SCA) was 3.184(p=0.024), while there were no differences between Tegillarca granosa(TG) and Sinonovacula constricta(SC) (T(TG-SC)=1.887, p=0.118) or between Tegillarca granosa and Saccostrea cucullata(SCA) (T(TG-SCA)=0.246, p=0.815). There were no differences of ammonia excretion rate among three shellfish (T(TG-SC)=0.977, p=0.373; T(TG-SCA)=2.369, p=0.064; T(SC-SCA)=1.002, p=0.362). The relationships between temperature (T) and oxygen consumption or ammonia excretion rate (Y) of three shellfish were described as lnY=lna+blnT(Y=aebT). To maintain their standard metabolism, Saccostrea cucullata consumed more protein for the O/N ratio ranging from 3.04 to 10.27, Tegillarca granosa and Sinonovacula constricta consumed both protein and lipids for the O/N ratio ranging from 4.69 to 28.55 and from 4.68 to 37.89.
2013, 35(6): 154-161.
Abstract:
The species composition of zooplankton in northern Beibu Gulf was studied based on the samples of Beibu Gulf collected during 2006-2007. The environmental factors which affected the number of species were also analyzed. The study showed that a total of 370 zooplankton taxa were identified, which belonging to 8 phyla, 19 Taxa. Hydromedusae and Copepoda were dominant taxa. The species number of zooplankton, varied seasonally, was highest in summer, followed by autumn, spring and winter. The distribution characteristics indicated that there was a gradual increase in the species number from shallow water to deep water. The wide-temperature-salinity group and the neritic low-salinity group which were dominant in this area formed a uniquely northern Beibu Gulf zooplankton community composition structure with few estuarine group and oceanic group. The temperate group appeared in spring might be brought in Beibu Gulf from neritic Guangdong by Qiongzhou Strait. The environmental factors which affected the number of species were varied during four seasons. Topographic feature, currents and water masses, phytoplankton were the main factors on zooplankton composition.
The species composition of zooplankton in northern Beibu Gulf was studied based on the samples of Beibu Gulf collected during 2006-2007. The environmental factors which affected the number of species were also analyzed. The study showed that a total of 370 zooplankton taxa were identified, which belonging to 8 phyla, 19 Taxa. Hydromedusae and Copepoda were dominant taxa. The species number of zooplankton, varied seasonally, was highest in summer, followed by autumn, spring and winter. The distribution characteristics indicated that there was a gradual increase in the species number from shallow water to deep water. The wide-temperature-salinity group and the neritic low-salinity group which were dominant in this area formed a uniquely northern Beibu Gulf zooplankton community composition structure with few estuarine group and oceanic group. The temperate group appeared in spring might be brought in Beibu Gulf from neritic Guangdong by Qiongzhou Strait. The environmental factors which affected the number of species were varied during four seasons. Topographic feature, currents and water masses, phytoplankton were the main factors on zooplankton composition.
2013, 35(6): 162-169.
Abstract:
Enteroviruses are one of the main agents of water-borne gastroenteritis. In order to learn the relationship between seasonal distribution as well as pollution type of infectious enterovirus and epidemiology,the integration of cell culture techniques and quantitative PCR (ICC-qPCR) was employed,surface seawater samples were seasonally collected from November 2010 to October 2011 to identify the contamination by infectious enteroviruses in winter seawater samples of Bohai Bay,Tianjin,China. 500 mL seawater was concentrated,cultivated for 48h,and then quantified by qPCR. The concentration of infectious enteroviruses were estimated at 0.2~196 PFU/L,average value was 60 PFU/L. During the four seasons,the concentration of enteroviruses in Summer and Autumn were 82 PFU/L and 110 PFU/L,respectively,which were much higher than the other two seasons. While the positive rate in Autumn is highest (85.7%),followed by Winter (71.4%). The main contaminated type was characterized as poliovirusⅠvaccine strains by sequencing. Besides,there were two strains of OPV-like Poliovirus TypeⅠand vaccine-derived poliovirus (VDPV). These results presented that the seasonal distribution and the main pollution types of enteroviruses were almost the same as epidemiology. Therefore,the ocean as the natural container of sewage,which provides a good opportunity for virus to survive and spread. There was a potential threat to public health. In order to avoid disease breaking out,the monitoring of enteroviruses in marine during epidemic season must be strengthened.
Enteroviruses are one of the main agents of water-borne gastroenteritis. In order to learn the relationship between seasonal distribution as well as pollution type of infectious enterovirus and epidemiology,the integration of cell culture techniques and quantitative PCR (ICC-qPCR) was employed,surface seawater samples were seasonally collected from November 2010 to October 2011 to identify the contamination by infectious enteroviruses in winter seawater samples of Bohai Bay,Tianjin,China. 500 mL seawater was concentrated,cultivated for 48h,and then quantified by qPCR. The concentration of infectious enteroviruses were estimated at 0.2~196 PFU/L,average value was 60 PFU/L. During the four seasons,the concentration of enteroviruses in Summer and Autumn were 82 PFU/L and 110 PFU/L,respectively,which were much higher than the other two seasons. While the positive rate in Autumn is highest (85.7%),followed by Winter (71.4%). The main contaminated type was characterized as poliovirusⅠvaccine strains by sequencing. Besides,there were two strains of OPV-like Poliovirus TypeⅠand vaccine-derived poliovirus (VDPV). These results presented that the seasonal distribution and the main pollution types of enteroviruses were almost the same as epidemiology. Therefore,the ocean as the natural container of sewage,which provides a good opportunity for virus to survive and spread. There was a potential threat to public health. In order to avoid disease breaking out,the monitoring of enteroviruses in marine during epidemic season must be strengthened.
2013, 35(6): 170-177.
Abstract:
Three time-series stations were assigned to the survey of the diurnal variations of phytoplankton biomass and community by the means of photosynthetic pigments at two stations in the northeastern South China Sea,summer 2008 and one station in the East China Sea in summer 2009,respectively. Remarkable diurnal variations of Chl a biomass (fluctuation between 34%~81%),with the maximum in the nighttime and minimum under daylight was the generality at the three stations under the effects of the tidal mixing and light. Diatoms were more preponderant at Sta. S702 (> 80%) than Sta. S305 and DH04 (35%~50%),at which the former was influenced by the coastal upwelling. The biomass of diatoms varied with total Chl a biomass synchronously,but the percentage of diatoms changed inversely. It implied the diversity of phytoplankton composition were also improved during the nighttime under the effect of tidal mixing. Prasinophytes was the second dominate group at Sta. S305,and also exhibited the same diurnal variation as total Chl a biomass. And the similar response of Synechococcus at Sta. DH04,the stratification status at the East China Sea,dominated at the upper mixed layer,also had the diurnal variation pattern with the total Chl a. But the dinoflagellates had a outburst at 03:30 as no indication of any diurnal variation. So the distribution might be the results of lateral transport of other water mass.
Three time-series stations were assigned to the survey of the diurnal variations of phytoplankton biomass and community by the means of photosynthetic pigments at two stations in the northeastern South China Sea,summer 2008 and one station in the East China Sea in summer 2009,respectively. Remarkable diurnal variations of Chl a biomass (fluctuation between 34%~81%),with the maximum in the nighttime and minimum under daylight was the generality at the three stations under the effects of the tidal mixing and light. Diatoms were more preponderant at Sta. S702 (> 80%) than Sta. S305 and DH04 (35%~50%),at which the former was influenced by the coastal upwelling. The biomass of diatoms varied with total Chl a biomass synchronously,but the percentage of diatoms changed inversely. It implied the diversity of phytoplankton composition were also improved during the nighttime under the effect of tidal mixing. Prasinophytes was the second dominate group at Sta. S305,and also exhibited the same diurnal variation as total Chl a biomass. And the similar response of Synechococcus at Sta. DH04,the stratification status at the East China Sea,dominated at the upper mixed layer,also had the diurnal variation pattern with the total Chl a. But the dinoflagellates had a outburst at 03:30 as no indication of any diurnal variation. So the distribution might be the results of lateral transport of other water mass.
2013, 35(6): 178-189.
Abstract:
Phytoplankton were sampled in the up 200 m in the Luzon Strait from 18th August to 19th September,2008,A total of 169 species belonging to 61 genera of 4 classes were identified. The species richness of dinoflagellates and diatoms were both closed to 50% of the total; 3 species belonging to 3 genera of Chrysophyta and 1 species of Cyanophyta were also identified. The dominant species were Amphisdinium carterae,Scrippsiella trochiodea,Chaetoceros sp. and Prorocentrum sp.. The phytoplankton abundances ranged from 0.08×106 to 9.48×106cells/m3,with average value of 1.448×106cells/m3. Dinoflagellates contributed to 74.68% of the total phytoplankton abundance and diatoms contribution was 24.96%. The horizontal distribution showed that phytoplankton in section B and station C5 were with relatively high abundances,phytoplankton were dominated by dinoflagellates which were mainly in the middle of the strait,while diatoms were mainly in the vicinity of the Taiwan Island or the Luzon Island; The horizontal distribution demonstrated that phytoplankton dramatically decreased below 50m. Combined with the hydrologic data,Phytoplankton were clustered into 3 types of community,which was influenced by the South China Sea water,the Kuroshio water and mixed water respectively. There were higher species richness,water column-integrated abundances and diatoms/dinoflagellates abundance ratio at the frontal zone of the South China Sea and the Kuroshio than those at the adjacent zones,implying significant frontal effect on phytoplankton community structure.
Phytoplankton were sampled in the up 200 m in the Luzon Strait from 18th August to 19th September,2008,A total of 169 species belonging to 61 genera of 4 classes were identified. The species richness of dinoflagellates and diatoms were both closed to 50% of the total; 3 species belonging to 3 genera of Chrysophyta and 1 species of Cyanophyta were also identified. The dominant species were Amphisdinium carterae,Scrippsiella trochiodea,Chaetoceros sp. and Prorocentrum sp.. The phytoplankton abundances ranged from 0.08×106 to 9.48×106cells/m3,with average value of 1.448×106cells/m3. Dinoflagellates contributed to 74.68% of the total phytoplankton abundance and diatoms contribution was 24.96%. The horizontal distribution showed that phytoplankton in section B and station C5 were with relatively high abundances,phytoplankton were dominated by dinoflagellates which were mainly in the middle of the strait,while diatoms were mainly in the vicinity of the Taiwan Island or the Luzon Island; The horizontal distribution demonstrated that phytoplankton dramatically decreased below 50m. Combined with the hydrologic data,Phytoplankton were clustered into 3 types of community,which was influenced by the South China Sea water,the Kuroshio water and mixed water respectively. There were higher species richness,water column-integrated abundances and diatoms/dinoflagellates abundance ratio at the frontal zone of the South China Sea and the Kuroshio than those at the adjacent zones,implying significant frontal effect on phytoplankton community structure.
2013, 35(6): 190-194.
Abstract:
The depth of sulfate-metnane interface (SMI) in sediments could indicate occurring status of methane hydrate. By systimatically paralell analysis of pore water geochemical data and authgenic cabonate oxygen and carbon isotopic data available from the potential gas hydrate areas of the northern slope of the South China Sea (SCS),the implication of spatial variation of sulfate-metnane interface in sediments for occurring status of underlying methane hydrate in the northern slope of SCS was discussed. It was illustrated that the SMI in sediments of the northern slope of SCS tends to be shallow from the southwest to the northeast. The spatial variation of SMI exactly corresponds to accretion of released methane which was indicated by carbon isotope of the authigenic carbonate,implicating that the buried depth of underlying methane hydrate temds to be shallow,or decomposition of underlying methane hydrate temds to be intensive from the southwest to the northeast.
The depth of sulfate-metnane interface (SMI) in sediments could indicate occurring status of methane hydrate. By systimatically paralell analysis of pore water geochemical data and authgenic cabonate oxygen and carbon isotopic data available from the potential gas hydrate areas of the northern slope of the South China Sea (SCS),the implication of spatial variation of sulfate-metnane interface in sediments for occurring status of underlying methane hydrate in the northern slope of SCS was discussed. It was illustrated that the SMI in sediments of the northern slope of SCS tends to be shallow from the southwest to the northeast. The spatial variation of SMI exactly corresponds to accretion of released methane which was indicated by carbon isotope of the authigenic carbonate,implicating that the buried depth of underlying methane hydrate temds to be shallow,or decomposition of underlying methane hydrate temds to be intensive from the southwest to the northeast.
2013, 35(6): 195-203.
Abstract:
Based on historical data collected from the southern Yellow Sea (34.25°~37.45°N,122.00°~124.00°E) in 1959,1982,1998-2000 and 2007-2010,interannual temporal-spatial variations in abundance of the dominant zooplankton species Calanus sinicus,Sagitta crassa,Euphausia pacifica,were studied. Correlation analysis was carried out between the species abundance and environmental factors including temperature,salinity and the Pacific Decadal Oscillation (PDO). PDO index is an indicator of climate changes in the Pacific Ocean,north of 20° N. The periods of 1959 and 1982 were in warm phase with positive PDO values,while those of 1998-2000,2007-2010 were in cool phase with negative PDO value. Results showed that seasonal abundance distributions of C. sinicus,E. pacifica and S. crassa varied with seasons in different years. Temperature had more influences on the abundance distributions of C. sinicus and E. pacifica,while salinity showed more influences on S.crassa. C. sinicus and E. pacifica abundance were higher in cold year of 2007-2010,while S. crassa abundance were higher during warm years of 1959 and 1982. Monthly abundances of C. sinicus and E. pacifica were significant correlated with PDO index but lagged behind about 3 months,and those of S.crassa had significant correlation with concurrent month PDO index.
Based on historical data collected from the southern Yellow Sea (34.25°~37.45°N,122.00°~124.00°E) in 1959,1982,1998-2000 and 2007-2010,interannual temporal-spatial variations in abundance of the dominant zooplankton species Calanus sinicus,Sagitta crassa,Euphausia pacifica,were studied. Correlation analysis was carried out between the species abundance and environmental factors including temperature,salinity and the Pacific Decadal Oscillation (PDO). PDO index is an indicator of climate changes in the Pacific Ocean,north of 20° N. The periods of 1959 and 1982 were in warm phase with positive PDO values,while those of 1998-2000,2007-2010 were in cool phase with negative PDO value. Results showed that seasonal abundance distributions of C. sinicus,E. pacifica and S. crassa varied with seasons in different years. Temperature had more influences on the abundance distributions of C. sinicus and E. pacifica,while salinity showed more influences on S.crassa. C. sinicus and E. pacifica abundance were higher in cold year of 2007-2010,while S. crassa abundance were higher during warm years of 1959 and 1982. Monthly abundances of C. sinicus and E. pacifica were significant correlated with PDO index but lagged behind about 3 months,and those of S.crassa had significant correlation with concurrent month PDO index.
2013, 35(6): 204-209.
Abstract:
To evaluate the marine water quality of West Guangdong Prcvince, China, an assumptive random sample comprising 400 stations (at each station there are 13 water quality indicators) is established according to the National Water Quality Standards (GB 3097-1997).The 13 indexes are filtered with a stepwise discriminant analysis method in terms of their water quality discriminant ability. Five indicators with distinguishing discriminant ability are picked out. They are a chemical oxygen demand, oil, cadmium content, total phosphorus and total nitrogen. A discriminant function and a water quality classification plate are thereafter established with these five indicators. The method avoides introducing too many indicators to have adverse impact on the water quality evaluation model. The above water quality classification plate is applied to evaluating the marine water quality of 40 stations in West Guangdong Province in 2010. Compared with the result provided by Zhanjiang Oceanic and Fishery Environmental Monitoring Station, it is found that the matching rate of 40 stations in this area is 95%. It indicates that the plate has a good application effect. It can be used as an effective way to evaluate the marine water quality by using multi-indicators.
To evaluate the marine water quality of West Guangdong Prcvince, China, an assumptive random sample comprising 400 stations (at each station there are 13 water quality indicators) is established according to the National Water Quality Standards (GB 3097-1997).The 13 indexes are filtered with a stepwise discriminant analysis method in terms of their water quality discriminant ability. Five indicators with distinguishing discriminant ability are picked out. They are a chemical oxygen demand, oil, cadmium content, total phosphorus and total nitrogen. A discriminant function and a water quality classification plate are thereafter established with these five indicators. The method avoides introducing too many indicators to have adverse impact on the water quality evaluation model. The above water quality classification plate is applied to evaluating the marine water quality of 40 stations in West Guangdong Province in 2010. Compared with the result provided by Zhanjiang Oceanic and Fishery Environmental Monitoring Station, it is found that the matching rate of 40 stations in this area is 95%. It indicates that the plate has a good application effect. It can be used as an effective way to evaluate the marine water quality by using multi-indicators.
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