2007 Vol. 29, No. 5
Display Method:
2007, 29(5): 1-9.
Abstract:
The Zhoushan fishing ground is located in the shallow-water area of the northwest East China Sea.The formation and displacement of the fishing ground and variations in fishing season and fish crop are mainly affected by hydrologic conditions and nutrient contents there, whose variations, to agreat extent, depend on the occupancy range and vanishing-growing changes in water masses.Using the data observed before the year of 1990, the water masses in the northwest East China sea have been studied by some scientists at home and abroad, but the study on the water mass in this sea area after completion in the three gorges engineering has been not reported sofar.In this work, based on CTD and nutrient data obtained during the summer of 2001 and the winter of 2002, the water masses in Zhoushan fishing ground and adjacent region were divided by using the fuzzy clustering method, and the seasonal characteristics in distributions, thermohaline properties and nutrient contents in the water masses in this area were analyzed.The results showed that there are distinct seasonal characteristics in the distributions, ranges, therm ohaline property and nutrient contents of the water masses in this area.In the whole study area, there are three water masses, namely, Jiang-Zhe Coastal Water (JCW), Taiwan Warm Current Surface Water(TWCSW) and Yellow Sea(Huanghai Sea) Mixing Water (YSMW) in winter, while there are four water masses, namely, the JCW, the TWCSW, Taiwan Warm Current Deep Water (TWCDW) and the YSMW in summer.The JCW has a relative small occupancy range, low temperature, high salinity and high nutrients in winter; while it has a relative large occupancy range, high temperature, low salinity and low nutrients in summer.The TWCSW extends farther northwards in winter than in summer and its thickness is much larger in winter than in summer.In the TWCSW, temperature is low, salinity is high, SiO3-Si and NO3-N are relative high, and PO4-P is low in winter, while the temperature high, salinitylow, SiO3-Si and NO3-N relative low, and PO4-P high in summer.The TWCDW is a seasonal water mass, and there are relative rich nutrients in it.There are some seasonal charact eristics in the occupancy range and nutrient contents of the YSMW.
The Zhoushan fishing ground is located in the shallow-water area of the northwest East China Sea.The formation and displacement of the fishing ground and variations in fishing season and fish crop are mainly affected by hydrologic conditions and nutrient contents there, whose variations, to agreat extent, depend on the occupancy range and vanishing-growing changes in water masses.Using the data observed before the year of 1990, the water masses in the northwest East China sea have been studied by some scientists at home and abroad, but the study on the water mass in this sea area after completion in the three gorges engineering has been not reported sofar.In this work, based on CTD and nutrient data obtained during the summer of 2001 and the winter of 2002, the water masses in Zhoushan fishing ground and adjacent region were divided by using the fuzzy clustering method, and the seasonal characteristics in distributions, thermohaline properties and nutrient contents in the water masses in this area were analyzed.The results showed that there are distinct seasonal characteristics in the distributions, ranges, therm ohaline property and nutrient contents of the water masses in this area.In the whole study area, there are three water masses, namely, Jiang-Zhe Coastal Water (JCW), Taiwan Warm Current Surface Water(TWCSW) and Yellow Sea(Huanghai Sea) Mixing Water (YSMW) in winter, while there are four water masses, namely, the JCW, the TWCSW, Taiwan Warm Current Deep Water (TWCDW) and the YSMW in summer.The JCW has a relative small occupancy range, low temperature, high salinity and high nutrients in winter; while it has a relative large occupancy range, high temperature, low salinity and low nutrients in summer.The TWCSW extends farther northwards in winter than in summer and its thickness is much larger in winter than in summer.In the TWCSW, temperature is low, salinity is high, SiO3-Si and NO3-N are relative high, and PO4-P is low in winter, while the temperature high, salinitylow, SiO3-Si and NO3-N relative low, and PO4-P high in summer.The TWCDW is a seasonal water mass, and there are relative rich nutrients in it.There are some seasonal charact eristics in the occupancy range and nutrient contents of the YSMW.
2007, 29(5): 10-20.
Abstract:
The structures of temperature and salinity and characteristics of current are analyzed by temperature and salinity data received from the cruise of northeast South China Sea(SCS) during late winter-early spring, 2001, combined with SeaWiFs data at the same period.The results indicate that the current is mainly dominated by a sub-basin scale cold cyclonic-gyre.This cold gyre shows double-core structure, and the vertical scale can touch the depth of 1 000 m.Water exchange about the inboard transects of Luzon Strait shows that water enter into SCS above 600 m, and flowout on the south of transect (south of 20×N) at middle and deep layers.The net transport of water from Luzon Strait is about 6.9×106m3/s.And the direct intrusion of Kuroshio cannot exceed 120.5°E.But part of Kuroshio water can arrive at the southwest of Taiwan along shelf, some of which even extend to west of Dongsha Archipelago and change its characteristic by mixing with SCS water.
The structures of temperature and salinity and characteristics of current are analyzed by temperature and salinity data received from the cruise of northeast South China Sea(SCS) during late winter-early spring, 2001, combined with SeaWiFs data at the same period.The results indicate that the current is mainly dominated by a sub-basin scale cold cyclonic-gyre.This cold gyre shows double-core structure, and the vertical scale can touch the depth of 1 000 m.Water exchange about the inboard transects of Luzon Strait shows that water enter into SCS above 600 m, and flowout on the south of transect (south of 20×N) at middle and deep layers.The net transport of water from Luzon Strait is about 6.9×106m3/s.And the direct intrusion of Kuroshio cannot exceed 120.5°E.But part of Kuroshio water can arrive at the southwest of Taiwan along shelf, some of which even extend to west of Dongsha Archipelago and change its characteristic by mixing with SCS water.
2007, 29(5): 21-30.
Abstract:
With the 24-month com posite Sea Surface Temperature Anomalies (SSTAs) by 8 distinct El Niño events selected from 1949 to 1998 and the corresponding climatological SST during the same period, three numerical experiments with 10 realizations for each, such as the Control Experiment (CTRL), Tropical Ocean Global Atmosphere (TOGA) and Pacific Ocean Global Atmosphere (TOGA-NP), are carried out, so as to reveal the int erannual climate responses of East Asia to an El Niño event during its different stages and the modulations to these responses of interannual SSTAs in the North Pacific.The results show that during the summer when an El Niño event develops, there exists a significant negative Pacific Japan (PJ) wave pattern over East Asia.The the western Pacific subtropical high is weaker and shifts east ward, and East Asian summer monsoon is streng thened.In China, there is much more precipitation in North East and Jiang huai Valley, however less precipitation in North China and Changjiang River Valley.During the winter when an El Niño event is matured, the East Asian trough is deepened, winter monsoon over the north of East Asia is intensified while there is a strong anticyclone over the subtropical western Pacific.In China, there is much more precipitation in South China.During the summer when an El Niño event decays, the atmosphere circulation response and precipitation in China are nearly completely opposite to the summer when an El Niño event develops.At the same time, the inter annual SSTAs in North Pacific indeed has some modulations to the atmosphere response in East Asia to an El Niño event, and their impacts can make the simulated precipitation in China much more resembling to the observations.
With the 24-month com posite Sea Surface Temperature Anomalies (SSTAs) by 8 distinct El Niño events selected from 1949 to 1998 and the corresponding climatological SST during the same period, three numerical experiments with 10 realizations for each, such as the Control Experiment (CTRL), Tropical Ocean Global Atmosphere (TOGA) and Pacific Ocean Global Atmosphere (TOGA-NP), are carried out, so as to reveal the int erannual climate responses of East Asia to an El Niño event during its different stages and the modulations to these responses of interannual SSTAs in the North Pacific.The results show that during the summer when an El Niño event develops, there exists a significant negative Pacific Japan (PJ) wave pattern over East Asia.The the western Pacific subtropical high is weaker and shifts east ward, and East Asian summer monsoon is streng thened.In China, there is much more precipitation in North East and Jiang huai Valley, however less precipitation in North China and Changjiang River Valley.During the winter when an El Niño event is matured, the East Asian trough is deepened, winter monsoon over the north of East Asia is intensified while there is a strong anticyclone over the subtropical western Pacific.In China, there is much more precipitation in South China.During the summer when an El Niño event decays, the atmosphere circulation response and precipitation in China are nearly completely opposite to the summer when an El Niño event develops.At the same time, the inter annual SSTAs in North Pacific indeed has some modulations to the atmosphere response in East Asia to an El Niño event, and their impacts can make the simulated precipitation in China much more resembling to the observations.
2007, 29(5): 31-39.
Abstract:
Based on the analyses of fundamental feature of sea surface emperature variation in the Indian Ocean, particularly on the dipole in the equatorial Indian Ocean (IOD) and its influences, the impacts of the IOD on the Asian monsoon climate variation is studied by using numerical simulation with a GCM (IAP9L).The results show that the atmospheric circulation and precipitation over the Indian Ocean, South Asia and East Asia are quite sensitive to the forcing of anomalous SST in the equatorial Indian Ocean.The positive phase of the IOD will lead to anomalous easterly wind over the equatorial eastern Indian Ocean-southern Indian Peninsula the Arabian Sea, and anomalous anticyclonic circulation over the Bay of Bengal-China/Indian Peninsula.Thus it plays an important role in decreasing summer rainfall in the Indian Peninsula, South part of China/Indian Peninsula and Indonesia area, and increasing summer rainfall in southern China and East Africa.The negative phase of the IOD will lead to anomalous westerly wind over the equatorial eastern Indian Ocean and anom alous cyclonic circulation over the Bay of Bengal-China/Indian Peninsula.Thus it plays an important role in increasing summer rainfall in the Indian Peninsula, south part of China/Indian Peninsula and Indonesia area, and decreasing summer rainfall in southern China, the Bay of Bengal and East Africa.The simulation results in this paper are similar with that in the data analyses, the important impact of the IOD on climate variation in Asian monsoon area has been exposed practically.
Based on the analyses of fundamental feature of sea surface emperature variation in the Indian Ocean, particularly on the dipole in the equatorial Indian Ocean (IOD) and its influences, the impacts of the IOD on the Asian monsoon climate variation is studied by using numerical simulation with a GCM (IAP9L).The results show that the atmospheric circulation and precipitation over the Indian Ocean, South Asia and East Asia are quite sensitive to the forcing of anomalous SST in the equatorial Indian Ocean.The positive phase of the IOD will lead to anomalous easterly wind over the equatorial eastern Indian Ocean-southern Indian Peninsula the Arabian Sea, and anomalous anticyclonic circulation over the Bay of Bengal-China/Indian Peninsula.Thus it plays an important role in decreasing summer rainfall in the Indian Peninsula, South part of China/Indian Peninsula and Indonesia area, and increasing summer rainfall in southern China and East Africa.The negative phase of the IOD will lead to anomalous westerly wind over the equatorial eastern Indian Ocean and anom alous cyclonic circulation over the Bay of Bengal-China/Indian Peninsula.Thus it plays an important role in increasing summer rainfall in the Indian Peninsula, south part of China/Indian Peninsula and Indonesia area, and decreasing summer rainfall in southern China, the Bay of Bengal and East Africa.The simulation results in this paper are similar with that in the data analyses, the important impact of the IOD on climate variation in Asian monsoon area has been exposed practically.
2007, 29(5): 40-47.
Abstract:
Traditional methods to extract ocean wave eddy information from remotely sensed imagery mainly use the edge detection technology such as Canny and Hough operators.However, owing to the complexities of ocean eddies and imagest hemselves, it is sometimes difficult to successfully detect ocean eddiesusing these methods.A multifractal filtering technology is proposed for the extraction of ocean eddies and demonst rated using NASA MODIS, SeaWiFS and NOAA satellite data set in the typical area, such as western boundary current.Results are demonst rated that the new method has a superior performance over the traditional methods.
Traditional methods to extract ocean wave eddy information from remotely sensed imagery mainly use the edge detection technology such as Canny and Hough operators.However, owing to the complexities of ocean eddies and imagest hemselves, it is sometimes difficult to successfully detect ocean eddiesusing these methods.A multifractal filtering technology is proposed for the extraction of ocean eddies and demonst rated using NASA MODIS, SeaWiFS and NOAA satellite data set in the typical area, such as western boundary current.Results are demonst rated that the new method has a superior performance over the traditional methods.
2007, 29(5): 48-54.
Abstract:
The content and distribution of biogenic silica were investigated in sediment cores from the Southern Ocean (Prydz Bay) during the CHINARE-18/21 cruise.The results show that the content of biogenic silica is ranged from 4.89% to 85.41%, and the average content of biogenic silica is 30.90%, the highest value occurs at the IV-10 station.The profile of BSiO2 is contrast to the profile of SiLicate in the interstitial water.The contents of biogenic silica and organic carbon in the surface sediments in the central area of Prydz Baygyre were much higher than those in other area, and closely related to the Chl a content and primary productivity of phyt oplankton in the surface water column.
The content and distribution of biogenic silica were investigated in sediment cores from the Southern Ocean (Prydz Bay) during the CHINARE-18/21 cruise.The results show that the content of biogenic silica is ranged from 4.89% to 85.41%, and the average content of biogenic silica is 30.90%, the highest value occurs at the IV-10 station.The profile of BSiO2 is contrast to the profile of SiLicate in the interstitial water.The contents of biogenic silica and organic carbon in the surface sediments in the central area of Prydz Baygyre were much higher than those in other area, and closely related to the Chl a content and primary productivity of phyt oplankton in the surface water column.
2007, 29(5): 55-68.
Abstract:
The major elements, rare earth elements(REE) and trace elements of 4 basalt samples from the central and western Pacific ferrom anganese crust provinces have been analyzed using chemical methods and ICP-MS, respectively.The results indicate that the samples have been extensively altered and that the contents of their major elements have changed significantly, with the samples losing the characteristics of the original rocks.However, the similarity of REE partition patterns and trace element contents of basalt samples to those of fresh oceanic island basalts(OIB) indicate that the basalt samples originated as oceanicisl and basalts(OIB).Because of low-temperature alteration, the contents of Al2O3, Fe2O3, MnO, K2O, and P2O5 increased relative to fresh oceanic island basalts, w hile MgO and FeO decreased.Active components, such as magnesium and iron, were leached from OIB resulting in the relative enrichment of SiO2 of the samples than fresh OIB(appeare in standard mineral quartz), although the samples having lower SiO2 contents (40.4%~41.4%) than the lower limit (43%) of fresh basalt.The leaching of active components can cause the relative enrichment of REE of altered basalts, while the precipitation of REE-rich ferromanganese oxides in vesicles and fissures of altered basalts not only causes an increase of REE contents, but also induces fractionation of LREE and HREE, thereby increasing of ∑c(Ce)/∑c(Yb) ratios of the samples.Based on the enrichment mechanism of REE contents of altered basalts, the theoretical quantities of precipitated ferromanganese oxides and the depleted quantities of active components were calculated for perunit mass of fresh basalt.As a result of low-temperatrue alteration, the depleted quantities of active components for per unit mass of fresh basalts vary in the range of 0.150~0.657, and the precipitated quantities of ferromanganese oxides for per unit mass of fresh basalts vary in the range of 0.006~0.042.Of the major elements, the two most depleted are iron, and magnesium, with 18.28%~70.95% of iron and 44.50~93.94% of magnesium in the fresh basalts was leached out.This exceeded the depletion ratios of bulk samples(15.0%~65.7%), and as a result the samples are depleted in iron and magnesium relative to fresh basalts.The negative depletion quantities of aluminium, potassium, and phosphorus for some samples resulted from the precipitation of zeolite in vesicles of samples and phosphatisation of the basalts.Theoretical calculation and geochemistry results both indicate that low-temperature alteration of basalts can supply abundant among of metals to seawater, and may play an important role in metal cycle of the ocean.
The major elements, rare earth elements(REE) and trace elements of 4 basalt samples from the central and western Pacific ferrom anganese crust provinces have been analyzed using chemical methods and ICP-MS, respectively.The results indicate that the samples have been extensively altered and that the contents of their major elements have changed significantly, with the samples losing the characteristics of the original rocks.However, the similarity of REE partition patterns and trace element contents of basalt samples to those of fresh oceanic island basalts(OIB) indicate that the basalt samples originated as oceanicisl and basalts(OIB).Because of low-temperature alteration, the contents of Al2O3, Fe2O3, MnO, K2O, and P2O5 increased relative to fresh oceanic island basalts, w hile MgO and FeO decreased.Active components, such as magnesium and iron, were leached from OIB resulting in the relative enrichment of SiO2 of the samples than fresh OIB(appeare in standard mineral quartz), although the samples having lower SiO2 contents (40.4%~41.4%) than the lower limit (43%) of fresh basalt.The leaching of active components can cause the relative enrichment of REE of altered basalts, while the precipitation of REE-rich ferromanganese oxides in vesicles and fissures of altered basalts not only causes an increase of REE contents, but also induces fractionation of LREE and HREE, thereby increasing of ∑c(Ce)/∑c(Yb) ratios of the samples.Based on the enrichment mechanism of REE contents of altered basalts, the theoretical quantities of precipitated ferromanganese oxides and the depleted quantities of active components were calculated for perunit mass of fresh basalt.As a result of low-temperatrue alteration, the depleted quantities of active components for per unit mass of fresh basalts vary in the range of 0.150~0.657, and the precipitated quantities of ferromanganese oxides for per unit mass of fresh basalts vary in the range of 0.006~0.042.Of the major elements, the two most depleted are iron, and magnesium, with 18.28%~70.95% of iron and 44.50~93.94% of magnesium in the fresh basalts was leached out.This exceeded the depletion ratios of bulk samples(15.0%~65.7%), and as a result the samples are depleted in iron and magnesium relative to fresh basalts.The negative depletion quantities of aluminium, potassium, and phosphorus for some samples resulted from the precipitation of zeolite in vesicles of samples and phosphatisation of the basalts.Theoretical calculation and geochemistry results both indicate that low-temperature alteration of basalts can supply abundant among of metals to seawater, and may play an important role in metal cycle of the ocean.
2007, 29(5): 69-73.
Abstract:
The accumulation rate has been evaluated based on the dating data of 136 sediment cores taken from areas deeper than 100 m in the South China Sea since the last glaciation.The average annual deposit amount is 152.3 Mt/a during MIS (marine isotope stage) 1 and 215.2 Mt/a during MIS 2 respectively, which are mainly contributed by terrigenous sediments.The accumulation rate is the highest in southwestern continental slopes followed by northeastern area, and lower in other part of the South China Sea during both of the last glaciation and Holocene.Although the accumulation rate during MIS 2 is much higher than that during MIS 1 in most part of the South China Sea, it has opposite trends near the rapidly accumulated areas because of more active side and downslope transport.
The accumulation rate has been evaluated based on the dating data of 136 sediment cores taken from areas deeper than 100 m in the South China Sea since the last glaciation.The average annual deposit amount is 152.3 Mt/a during MIS (marine isotope stage) 1 and 215.2 Mt/a during MIS 2 respectively, which are mainly contributed by terrigenous sediments.The accumulation rate is the highest in southwestern continental slopes followed by northeastern area, and lower in other part of the South China Sea during both of the last glaciation and Holocene.Although the accumulation rate during MIS 2 is much higher than that during MIS 1 in most part of the South China Sea, it has opposite trends near the rapidly accumulated areas because of more active side and downslope transport.
2007, 29(5): 74-80.
Abstract:
A terrestrial flux in sediments is potential not only to reflect the paleoceanog raphic evolution of sedimentary basin, but also to reveal the paleoclimatic changes in source regions.The sediments of Core DGKS9603 from the Okinawa Trough were quantitatively partitioned into terrestrial, volcanic and biogenitic source end members, using Q-mode factor analysis for geochemical compositional data.Combined with the density of dried sediments and sedimentation rate, the terrest rial flux in the sediments from the Okinawa Trough since the last 35 000 a has been estimated to reveal the response of terrest rial supply to climate changes.It is demonst rated that the terrestrial supply to the Okinawa Trough has mainly derived from China's Mainland terrestrial mass via the Changjiang River.On the glacial-interglacial scale, terrestrial supply to the Okinawa Trough was mainly controlled by sea level changes via changing the relative distance between the Changjiang River mouth and the Okinawa Trough.During the Last Glacial maximum and cooling events (Heinrich events), the East Asian winter monsoon would have intensified and thus provided much eolain dust to the Okinawa Trough.The Heinrich events recorded in the Okinawa Trough would be related to the intensifitation of the East Asian winter monsoon.
A terrestrial flux in sediments is potential not only to reflect the paleoceanog raphic evolution of sedimentary basin, but also to reveal the paleoclimatic changes in source regions.The sediments of Core DGKS9603 from the Okinawa Trough were quantitatively partitioned into terrestrial, volcanic and biogenitic source end members, using Q-mode factor analysis for geochemical compositional data.Combined with the density of dried sediments and sedimentation rate, the terrest rial flux in the sediments from the Okinawa Trough since the last 35 000 a has been estimated to reveal the response of terrest rial supply to climate changes.It is demonst rated that the terrestrial supply to the Okinawa Trough has mainly derived from China's Mainland terrestrial mass via the Changjiang River.On the glacial-interglacial scale, terrestrial supply to the Okinawa Trough was mainly controlled by sea level changes via changing the relative distance between the Changjiang River mouth and the Okinawa Trough.During the Last Glacial maximum and cooling events (Heinrich events), the East Asian winter monsoon would have intensified and thus provided much eolain dust to the Okinawa Trough.The Heinrich events recorded in the Okinawa Trough would be related to the intensifitation of the East Asian winter monsoon.
2007, 29(5): 81-87.
Abstract:
On the basis of three geological models and several orebody boundaries, a grid subdivision and integral method has been proposed to calculate and evaluate the resource quantity of cobalt-rich crust on the seamounts of the central Pacific Ocean.The formulas of this method are deduced, and the interface of program module is designed, this method is carried out in the software "Auto mapping system of submarine topographic and geomorphic MBChart".This method and the program will possibly become a potential tool to calculate the resource quantity of seamounts and block out the target diggings during China's next five years plan.
On the basis of three geological models and several orebody boundaries, a grid subdivision and integral method has been proposed to calculate and evaluate the resource quantity of cobalt-rich crust on the seamounts of the central Pacific Ocean.The formulas of this method are deduced, and the interface of program module is designed, this method is carried out in the software "Auto mapping system of submarine topographic and geomorphic MBChart".This method and the program will possibly become a potential tool to calculate the resource quantity of seamounts and block out the target diggings during China's next five years plan.
2007, 29(5): 88-94.
Abstract:
In the past 50 a, the East Asian summer monsoon intensity index has changed significantly, which has led to some response to the water cycle system of the Huanghe River Basin.The variation of the summer monsoon intensity index shows three stages: (1) from 1951 to 1963, the summer monsoon intensity index increased; (2) from 1963 to 1965, the summer monsoon intesity declined sharply, which may be regarded as an abrupt change; (3) from 1965 to 2000, the summer monsoon intensity index remained at low levels and showed a decreasing trend.The variation of annual precipitation is synchronic with that in the summer monsoon intensity index.From 1950 to 1970, annual air temperature showed slight decrease in large fluctuations.From 1970, a significant increasing trend can be seen.Climate change may result in a change in sediment flux into the sea, and therefore a change in the rate of land accretion of the delta.The annual rate of land accretion of delta and sediment flux into the sea tended to increase from 1952 to 1964, but decreased after 1964, its tendency was similar to the summer monsoon intensity index.Apart from the climate factor, human activity such as water and soil conservation measures and water division in the drainage basin also have some effect on land accretion of the Huanghe River Delta.A multiple regression analysis indicates that the rate of land accretion of the delta decreased with the decrease in the summer monsoon intensity index, the increase in annual temperature, the increase in the area of water and soil conservation measures and increase in water diversion.The contribution of the variations of the above influencing variables to the variation of the rate of land accretion of the delta was calculated as 34.94%, 3.80%, 53.82% and 7.44%, respectively.The cont ribution of the two climate factors sums 38.7%, indicating that the influence of global climate change on the variation in the land accretion of the Huanghe River Delta is significant.
In the past 50 a, the East Asian summer monsoon intensity index has changed significantly, which has led to some response to the water cycle system of the Huanghe River Basin.The variation of the summer monsoon intensity index shows three stages: (1) from 1951 to 1963, the summer monsoon intensity index increased; (2) from 1963 to 1965, the summer monsoon intesity declined sharply, which may be regarded as an abrupt change; (3) from 1965 to 2000, the summer monsoon intensity index remained at low levels and showed a decreasing trend.The variation of annual precipitation is synchronic with that in the summer monsoon intensity index.From 1950 to 1970, annual air temperature showed slight decrease in large fluctuations.From 1970, a significant increasing trend can be seen.Climate change may result in a change in sediment flux into the sea, and therefore a change in the rate of land accretion of the delta.The annual rate of land accretion of delta and sediment flux into the sea tended to increase from 1952 to 1964, but decreased after 1964, its tendency was similar to the summer monsoon intensity index.Apart from the climate factor, human activity such as water and soil conservation measures and water division in the drainage basin also have some effect on land accretion of the Huanghe River Delta.A multiple regression analysis indicates that the rate of land accretion of the delta decreased with the decrease in the summer monsoon intensity index, the increase in annual temperature, the increase in the area of water and soil conservation measures and increase in water diversion.The contribution of the variations of the above influencing variables to the variation of the rate of land accretion of the delta was calculated as 34.94%, 3.80%, 53.82% and 7.44%, respectively.The cont ribution of the two climate factors sums 38.7%, indicating that the influence of global climate change on the variation in the land accretion of the Huanghe River Delta is significant.
2007, 29(5): 95-101.
Abstract:
The BHC and DDT contents in three species of Nemipterus fish from continental shelf of northern South China Sea were determined by GC-ECD method in order on explore the effect of BHC and DDT on fishery resources and quality of fishery products off shore.The data showed that the contents of BHC and DDT in the fish muscle were from 0.04 to 0.89 with mean of 0.26μg/kg (wet mass), and from 0.71 to 8.0 (3.1)μg/kg (wet mass), respectively, both were below the superior limits in fishery products published by home and abroad, and under the mean level of some marine fish from near shore in Asia and Pacific Ocean.The mean content of BHC or DDT in the fish muscle along Guangdong was higher than that of Taiwan Bank.No significant difference of mean content of BHC or DDT in the fish muscle were observed among the different species or between the near shore and off shore (P > 0.10).In the fish N.bathybius, pesticide contents were significantly higher in the liver and lower in the gill thread (P < 0.05).The tissue of N.bathybius containing pesticides from high to low was in the order of liver greater than abdomen muscle greater than back muscle greater than intestines greater than skin greater than gill thread for BHC, and liver greater than abdomen muscle greater than back muscle greater than skin≈intestines greater than gill thread for DDT.The content of pp-DDT, op-DDT positively related to lipid content in different tissues of N.bathybius (P < 0.05).
The BHC and DDT contents in three species of Nemipterus fish from continental shelf of northern South China Sea were determined by GC-ECD method in order on explore the effect of BHC and DDT on fishery resources and quality of fishery products off shore.The data showed that the contents of BHC and DDT in the fish muscle were from 0.04 to 0.89 with mean of 0.26μg/kg (wet mass), and from 0.71 to 8.0 (3.1)μg/kg (wet mass), respectively, both were below the superior limits in fishery products published by home and abroad, and under the mean level of some marine fish from near shore in Asia and Pacific Ocean.The mean content of BHC or DDT in the fish muscle along Guangdong was higher than that of Taiwan Bank.No significant difference of mean content of BHC or DDT in the fish muscle were observed among the different species or between the near shore and off shore (P > 0.10).In the fish N.bathybius, pesticide contents were significantly higher in the liver and lower in the gill thread (P < 0.05).The tissue of N.bathybius containing pesticides from high to low was in the order of liver greater than abdomen muscle greater than back muscle greater than intestines greater than skin greater than gill thread for BHC, and liver greater than abdomen muscle greater than back muscle greater than skin≈intestines greater than gill thread for DDT.The content of pp-DDT, op-DDT positively related to lipid content in different tissues of N.bathybius (P < 0.05).
2007, 29(5): 102-108.
Abstract:
The objective was to find and identify immune-related genes of Chinese shrimp (Fenneropenaeus chinensis) by panning phage display library T7 phage display libraries were constructed with the shrimp hemocyte mRNA following the manufactures instruction.The titer of the Library was 1.1×1011pfu/cm3.The library was panning by various ligands, including lipopoly saccharide, chitin and different kinds of bacteria, such as gram positive bacteria, Staphylococcusaureus, Bifidobacteriumlactis and Micrococcusluteus, and gramnegative bacteria, Escherichia coli, Vibrio anguillarum.After three rounds of phage panning, the inserts in the phage was amplified by PCR with T7 select 10-3b vector primers, and subcloned into pMD 18T vecter for sequencing.The sequences were analyzed by BLAST Sixteen fragments were obtained.Among them, peritrophin, Proteinarg inine N-methyltransferase, thr mbospondin, RNA binding protein, and nuclear autoantigenic sperm protein which were firstly reported in Chinese shrimp.The expression profile of peritrophin was analyzed by Reverse Transcription-PCR (RT-PCR), the results showed that it was reducing expression in hemocytes, heart, stomach, gut, gill and sperm in infected shrimp.This surgested that the peritriphin may be involved in innate immunity.Other genes panned from the library need further study.
The objective was to find and identify immune-related genes of Chinese shrimp (Fenneropenaeus chinensis) by panning phage display library T7 phage display libraries were constructed with the shrimp hemocyte mRNA following the manufactures instruction.The titer of the Library was 1.1×1011pfu/cm3.The library was panning by various ligands, including lipopoly saccharide, chitin and different kinds of bacteria, such as gram positive bacteria, Staphylococcusaureus, Bifidobacteriumlactis and Micrococcusluteus, and gramnegative bacteria, Escherichia coli, Vibrio anguillarum.After three rounds of phage panning, the inserts in the phage was amplified by PCR with T7 select 10-3b vector primers, and subcloned into pMD 18T vecter for sequencing.The sequences were analyzed by BLAST Sixteen fragments were obtained.Among them, peritrophin, Proteinarg inine N-methyltransferase, thr mbospondin, RNA binding protein, and nuclear autoantigenic sperm protein which were firstly reported in Chinese shrimp.The expression profile of peritrophin was analyzed by Reverse Transcription-PCR (RT-PCR), the results showed that it was reducing expression in hemocytes, heart, stomach, gut, gill and sperm in infected shrimp.This surgested that the peritriphin may be involved in innate immunity.Other genes panned from the library need further study.
2007, 29(5): 109-116.
Abstract:
A nucleotide sequence analysis of mitochondrial cytochrome coxidase subunit I (COI) gene fragment was conducted among six family Vener idae clams, Meretrix meretrix L., 1758, Cyclina sinensis G., 1791, Mercenaria mercenaria L., 1758, Protothaca jedoensis L., 1874, Dosinia corrugata R., 1850, Ruditapes philippinarum A., 1850 and four populations of M.meretrix to determine the utility of this regions in identifying phylogeog raphic and phylog enetic structure.Nucleotide sequences of 709 bp in length were obtained from the mitochondrial DNA cytochrome coxidase subunit I (COI) gene for 18 Veneridae specimens representing six species and four geographical populations of M.meretrix, with A+T contents from 62.2% to 67.6%, which higher than G+C contents obviously.Analysis of sequence variation at the COI gene across six species revealed 311 variable sites, which 202 were par sim-informative sites.Translation of codons into amino acids indicated 85 varable sites.Analysis of sequence variation across four M.meretrix populations revealed 46 variable sites, which only two were parsim-informative sites.Translation of codons into amino acids indicated only one variable site.The phylogenetic tree of Veneridae clams was reconstructed by using COI gene sequences as marker, and with Solen grandis as outg roups.Tree topologies indicated that four M.meretrix populations formed a monophy letic group with its sister taxon C.sinensis, all Veneridae species form a clade, which was consistent with the tree based on morphological characters.This result reveals that the COI gene was an appropriate marker for studies of phylogeny and phylogeography of the Veneridae clams.
A nucleotide sequence analysis of mitochondrial cytochrome coxidase subunit I (COI) gene fragment was conducted among six family Vener idae clams, Meretrix meretrix L., 1758, Cyclina sinensis G., 1791, Mercenaria mercenaria L., 1758, Protothaca jedoensis L., 1874, Dosinia corrugata R., 1850, Ruditapes philippinarum A., 1850 and four populations of M.meretrix to determine the utility of this regions in identifying phylogeog raphic and phylog enetic structure.Nucleotide sequences of 709 bp in length were obtained from the mitochondrial DNA cytochrome coxidase subunit I (COI) gene for 18 Veneridae specimens representing six species and four geographical populations of M.meretrix, with A+T contents from 62.2% to 67.6%, which higher than G+C contents obviously.Analysis of sequence variation at the COI gene across six species revealed 311 variable sites, which 202 were par sim-informative sites.Translation of codons into amino acids indicated 85 varable sites.Analysis of sequence variation across four M.meretrix populations revealed 46 variable sites, which only two were parsim-informative sites.Translation of codons into amino acids indicated only one variable site.The phylogenetic tree of Veneridae clams was reconstructed by using COI gene sequences as marker, and with Solen grandis as outg roups.Tree topologies indicated that four M.meretrix populations formed a monophy letic group with its sister taxon C.sinensis, all Veneridae species form a clade, which was consistent with the tree based on morphological characters.This result reveals that the COI gene was an appropriate marker for studies of phylogeny and phylogeography of the Veneridae clams.
2007, 29(5): 117-122.
Abstract:
Calanus sinicus, an independent species divided from C.pacificus, dominated in all main seas of China, plays the same role in China neritic ecosystem as C.finmarchicus in Atlantic.As a mega-copepod, C.sinicus has been widely studied because of its connecting link between the preceding and the following in marine food webs.In Xiamen Harbor, located opposite of Taiwan Island, C.sinicus usually appears in the late autumn or early winter and disappears at the beginning of summer.Then how can they spend the summer? Did they move into deeper waters or produce dormant eggs for oversummering? The present paper studies the egg types of C.sinicus in order to discuss whether C.sinicus produced dormant eggs.We collected female of C.sinicus by horizontal hauls with a 50cm diameter netequipped with a 500 m mesh in Xiamen Harbo revery 10~15 d from January to May in 2003 and 2004.In the laboratory, healthy females were chosen and placed individually in twenty-four wells tissue culture plate with full of sea water pumped from beach (salinity of 28~31) and filtered with fine sand.No food was supplied during culture.On the second morning, all eggs (except died eggs) newly released by the females were immediately transferred into glass slide.And the thickness of blister was measured under Olympus BH 2 LM.
Calanus sinicus, an independent species divided from C.pacificus, dominated in all main seas of China, plays the same role in China neritic ecosystem as C.finmarchicus in Atlantic.As a mega-copepod, C.sinicus has been widely studied because of its connecting link between the preceding and the following in marine food webs.In Xiamen Harbor, located opposite of Taiwan Island, C.sinicus usually appears in the late autumn or early winter and disappears at the beginning of summer.Then how can they spend the summer? Did they move into deeper waters or produce dormant eggs for oversummering? The present paper studies the egg types of C.sinicus in order to discuss whether C.sinicus produced dormant eggs.We collected female of C.sinicus by horizontal hauls with a 50cm diameter netequipped with a 500 m mesh in Xiamen Harbo revery 10~15 d from January to May in 2003 and 2004.In the laboratory, healthy females were chosen and placed individually in twenty-four wells tissue culture plate with full of sea water pumped from beach (salinity of 28~31) and filtered with fine sand.No food was supplied during culture.On the second morning, all eggs (except died eggs) newly released by the females were immediately transferred into glass slide.And the thickness of blister was measured under Olympus BH 2 LM.
2007, 29(5): 123-131.
Abstract:
On the basis of the data from four seasonal oceanog raphic censuses in the East China Sea (23.30~33 N, 118.30~128 E) in 1997~2000, the paper studies on adaptation and ecotype of Ostracoda in the East China Sea through curve fitting, forming mathematical model, calculating optimal temperature and salinity, consulting geographic distribution based on synchronous data of abundance and environmental factors.The results show that in the dominant species, Euconchoecia maimai, E Chierchiae, Cypridina dentate, E aculeate and E elongata are off shore subtropical water species with wide distribution.They can occur in north off shore waters because warm currents may take them from low latitude areas to there during winter and spring.The mathematical analyses show that optimal temperatures of Paraconchoecia decipiens, P echinata, P spinifera, Conchoecia magna, P oblonga and Porroecia porrect are over 25, and their optimal salinity over 34, mainly distributing in waters of Kuroshio, the Taiwan Warm Current and the Taiwan Strait, which all make the species qualified as oceanic tropical water species.Though Pseudoconchoecia concentrica and Conchoecia sp have low optimal temperature, characters of their geographic distribution ascribe the former to of fshore subtropical water species and the latter to temperate warm water species.The optimal temperatures of the rest species are between 15 and 20.Though most of their optimal salinity is over 34, these species can widely distribute in areas from the East China Sea to the Nansha archipelago with not high density and their distribution are related with warm currents so that they can be defined as offshore subtropical water species.
On the basis of the data from four seasonal oceanog raphic censuses in the East China Sea (23.30~33 N, 118.30~128 E) in 1997~2000, the paper studies on adaptation and ecotype of Ostracoda in the East China Sea through curve fitting, forming mathematical model, calculating optimal temperature and salinity, consulting geographic distribution based on synchronous data of abundance and environmental factors.The results show that in the dominant species, Euconchoecia maimai, E Chierchiae, Cypridina dentate, E aculeate and E elongata are off shore subtropical water species with wide distribution.They can occur in north off shore waters because warm currents may take them from low latitude areas to there during winter and spring.The mathematical analyses show that optimal temperatures of Paraconchoecia decipiens, P echinata, P spinifera, Conchoecia magna, P oblonga and Porroecia porrect are over 25, and their optimal salinity over 34, mainly distributing in waters of Kuroshio, the Taiwan Warm Current and the Taiwan Strait, which all make the species qualified as oceanic tropical water species.Though Pseudoconchoecia concentrica and Conchoecia sp have low optimal temperature, characters of their geographic distribution ascribe the former to of fshore subtropical water species and the latter to temperate warm water species.The optimal temperatures of the rest species are between 15 and 20.Though most of their optimal salinity is over 34, these species can widely distribute in areas from the East China Sea to the Nansha archipelago with not high density and their distribution are related with warm currents so that they can be defined as offshore subtropical water species.
2007, 29(5): 132-145.
Abstract:
They were presented that the phytoplankt on species composition and cell abundance data based on the investigation in northern South China Sea (17°~23°N, 111°~117°E) which was carried out from 8 th February to 4th March 2004 with 149 samples taken from 30 grid stations.A total of 195 taxa (not include uncertain species) belonging to 110 genera of 5 phyla were identified by Utermhl method, in which Bacillariophyta were predominant and coexisted with Dinophyta.Chrysophyta which was mainly composed of coccolithophores and diazotrophs Cyanophyta were also common found in survey area.Few Chlorophyta were checked out at two stations near Zhujiang (Pearl River) Estuary.The dominant species in turn were Thalassionema nitzschioides Grunow, Thalassionema frauenfeldii Hallegraeff, Emiliania huxleyi (Lohmann) Hayet Mohler, Pseudo-nitzschia delicatissma Heiden, Thalassiothrix longissima Cleve & Grunow, Gephyrocapsa oceanica Kamptner, Prorocentrum dentatum Stein, Paralia sulcata (Ehrenberg) Cleve and Gyrodinium spirale Bergh, etc.Most of phytoplankt on taxa found in survey area was cosmopolit an species, warm-water species are also common, there were just few trophic-water, subtrophic-water or cold-water species.
They were presented that the phytoplankt on species composition and cell abundance data based on the investigation in northern South China Sea (17°~23°N, 111°~117°E) which was carried out from 8 th February to 4th March 2004 with 149 samples taken from 30 grid stations.A total of 195 taxa (not include uncertain species) belonging to 110 genera of 5 phyla were identified by Utermhl method, in which Bacillariophyta were predominant and coexisted with Dinophyta.Chrysophyta which was mainly composed of coccolithophores and diazotrophs Cyanophyta were also common found in survey area.Few Chlorophyta were checked out at two stations near Zhujiang (Pearl River) Estuary.The dominant species in turn were Thalassionema nitzschioides Grunow, Thalassionema frauenfeldii Hallegraeff, Emiliania huxleyi (Lohmann) Hayet Mohler, Pseudo-nitzschia delicatissma Heiden, Thalassiothrix longissima Cleve & Grunow, Gephyrocapsa oceanica Kamptner, Prorocentrum dentatum Stein, Paralia sulcata (Ehrenberg) Cleve and Gyrodinium spirale Bergh, etc.Most of phytoplankt on taxa found in survey area was cosmopolit an species, warm-water species are also common, there were just few trophic-water, subtrophic-water or cold-water species.
2007, 29(5): 146-153.
Abstract:
It was for med based on the data obtained from the east and west regions of Chinese Contract Area in the NE of Pacific Ocean during 6 surveys, DY85-4, DY95-7, DY95-8, DY95-10, DY105-11 and DY105-12.14, in years from 1994 to 2003.The result shows that the maximum chlorophylla distribution was located under the subsurface water layer, following the general distribution pattern for Chlorophylla.It was measured that the chlorophylla around 0.1 mg/m3 was found from the surface water to 50 m depth and around 0.2~0.4 mg/m3 was from 50 to 100 m.It diminished below 100m depth and zeroed particularly at 150 m depth.The primary production(C) in range from 76.8~191.9 mg/(m2·d) with average 116.1 mg/(m2·d) was located in the east region, and the production from 73.1 to 222.5 mg/(m2·d) with average 127.1 mg/(m2·d) was in the west region.The picoplanktonic chlorophyll a in particle size from 0.2 to 2μm was accounted for more than 70% of the total and it decreased to less than 50% in depth below 125 m.The particles with size from 2 to 20μm and over 20μm were only accounted for less than 30% of the total at depth from 0 to 125 m while it rose above 50% below 125 m depth.It demonstrated that the primary production in both regions should be classified as the areas of lower productivity.
It was for med based on the data obtained from the east and west regions of Chinese Contract Area in the NE of Pacific Ocean during 6 surveys, DY85-4, DY95-7, DY95-8, DY95-10, DY105-11 and DY105-12.14, in years from 1994 to 2003.The result shows that the maximum chlorophylla distribution was located under the subsurface water layer, following the general distribution pattern for Chlorophylla.It was measured that the chlorophylla around 0.1 mg/m3 was found from the surface water to 50 m depth and around 0.2~0.4 mg/m3 was from 50 to 100 m.It diminished below 100m depth and zeroed particularly at 150 m depth.The primary production(C) in range from 76.8~191.9 mg/(m2·d) with average 116.1 mg/(m2·d) was located in the east region, and the production from 73.1 to 222.5 mg/(m2·d) with average 127.1 mg/(m2·d) was in the west region.The picoplanktonic chlorophyll a in particle size from 0.2 to 2μm was accounted for more than 70% of the total and it decreased to less than 50% in depth below 125 m.The particles with size from 2 to 20μm and over 20μm were only accounted for less than 30% of the total at depth from 0 to 125 m while it rose above 50% below 125 m depth.It demonstrated that the primary production in both regions should be classified as the areas of lower productivity.
2007, 29(5): 154-160.
Abstract:
An alginate lyase gene of Azotobacter chroococcum, called algL, has been cloned with PCR technique.The sequence encoding the mature peptide of alginate lyase of Azotobacter chroococcum was added with EcoRI and NotI.Then the gene was inserted into the Pichia pastoris vector pPIC9K and introduced into the host Pichia pastoris GS115 by PEG method.After screen, the recombinant Pichia pastoris strain was obtained and induced in 25mL methylot rophic culture medium.Expression of the algL gene in P.pastor is cells resulted in the expression of alginate lyase activity (1 400 U/cm3) and the appearance of a new protein of 43 kDa detected on SDS-PAGE.To characterize the recom binantenzyme, it was found that the optimum temperature is 40℃ at pH 8.5 and that activity of alginate lyase decreased rapidly when analyzed above 60℃.The activity of recom binant AlgL decreased by over 50% in the presence of 10 mmol/L Cu2+ or Fe2+, furthermore, 10mmol/L Co2+, Mn2+, Ca2+ or 1mmol/L Fe2+ decreased it by 20% respectively.Other cations including K+, Na+, Zn2+ did not affect significantly the enzymatic activity.
An alginate lyase gene of Azotobacter chroococcum, called algL, has been cloned with PCR technique.The sequence encoding the mature peptide of alginate lyase of Azotobacter chroococcum was added with EcoRI and NotI.Then the gene was inserted into the Pichia pastoris vector pPIC9K and introduced into the host Pichia pastoris GS115 by PEG method.After screen, the recombinant Pichia pastoris strain was obtained and induced in 25mL methylot rophic culture medium.Expression of the algL gene in P.pastor is cells resulted in the expression of alginate lyase activity (1 400 U/cm3) and the appearance of a new protein of 43 kDa detected on SDS-PAGE.To characterize the recom binantenzyme, it was found that the optimum temperature is 40℃ at pH 8.5 and that activity of alginate lyase decreased rapidly when analyzed above 60℃.The activity of recom binant AlgL decreased by over 50% in the presence of 10 mmol/L Cu2+ or Fe2+, furthermore, 10mmol/L Co2+, Mn2+, Ca2+ or 1mmol/L Fe2+ decreased it by 20% respectively.Other cations including K+, Na+, Zn2+ did not affect significantly the enzymatic activity.
2007, 29(5): 161-173.
Abstract:
A numerical model is developed with a new type of Boussinesq equations including utility velocity variables employed as the governing equations.In the present model, the seven-point finite difference scheme is used to discretize the spatial derivatives, the fifth-order Runge-Kutta-England scheme is employed to perform the time integration, and the appropriate out flow boundary condition is adopted.Systematic numerical modeling of wave propagation is performed with uniform depth from shallow to deep water and from linear to nonlinear waves.The calculation results show that the present numerical model with utility velocity variables is valid for greater water depth than that without utility velocity variables.The numerical simulation of wave propagation is also performed in a wave tank with a submerged dike, and the comparisons between experimental data and numerical solutions are made.The calculation results show that the present numerical model is more accurate than that without utility velocity variables.
A numerical model is developed with a new type of Boussinesq equations including utility velocity variables employed as the governing equations.In the present model, the seven-point finite difference scheme is used to discretize the spatial derivatives, the fifth-order Runge-Kutta-England scheme is employed to perform the time integration, and the appropriate out flow boundary condition is adopted.Systematic numerical modeling of wave propagation is performed with uniform depth from shallow to deep water and from linear to nonlinear waves.The calculation results show that the present numerical model with utility velocity variables is valid for greater water depth than that without utility velocity variables.The numerical simulation of wave propagation is also performed in a wave tank with a submerged dike, and the comparisons between experimental data and numerical solutions are made.The calculation results show that the present numerical model is more accurate than that without utility velocity variables.
2007, 29(5): 174-180.
Abstract:
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