The polycyclic aromatic hydrocarbons(PAHs) concentrations were determined in the root of three mangrove species(Kandelia candel, Avicennia marina and Bruguiera gymnorrhiza) and their growing environment(sediment) in m...The polycyclic aromatic hydrocarbons(PAHs) concentrations were determined in the root of three mangrove species(Kandelia candel, Avicennia marina and Bruguiera gymnorrhiza) and their growing environment(sediment) in mangrove wetlands of Jiulong River Estuary, Fujian, China. The total PAHs(16 parent PAHs) in mangrove sediments ranged from 193.44 to 270.53 ng/g dw, with a mean value of 231.76±31.78 ng/g dw. Compared with other mangrove and coastal marine sediments, the PAHs concentrations of all the sampling areas in this study were at relatively lower level. The total PAHs(13 parent PAHs) values varied from 30.83 to 62.73 ng/g dw in mangrove roots. Benzo[a]pyrene(five-ring), fluoranthene(four-ring) and pyrene(four-ring) dominated in mangrove sediments. Based on ratios of phenathrene/anthracene, fluoranthene/pyrene and fluoranthene/pyrene + fluoranthene, the main possible sources of surface sediment PAHs were identified as grass, wood or coal combustion for mangrove wetlands of Jiulong River Estuary. Naphthalene(two-ring) and phenathrene(three-ring) were the most abundant compounds in mangrove roots. Sediment-to-vegetation bioconcentration factors(BCF SV s) were calculated and their relationships with PAHs' physico-chemical properties were investigated. The average BCF SV s of PAHs for three mangrove species roots were almost all under the level of 1 except for naphthalene. Good linear relationship between BCF SV values for mangrove roots and PAHs water solubility, octanol-water partitioning coefficients was derived in present study. The solubility and the octanol-water partition coefficient were proved to be good predictors for the accumulation of PAHs in mangrove roots, respectively.展开更多
Four units and twenty-four zones of diatom have been discerned in the Borehole ZK5 in the estuarine plain of the Jiulong River, Fujian Province. Comprehensive analysis of these, together with microbiological assemblag...Four units and twenty-four zones of diatom have been discerned in the Borehole ZK5 in the estuarine plain of the Jiulong River, Fujian Province. Comprehensive analysis of these, together with microbiological assemblages and age determinations in some other boreholes, shows that during the Late Wurm Glacial, sea level of the study area rose and fell frequently, but had principally been in the environments of estuary-bay. This mainly resulted from the tectonic subouction. In this period 3 low sea levels occurred. at 18, 16 and 12 kaBP respectively. During Holocene, sea weter intruded massively and the sea level over the transgnaion maximum had been 5-10 m higher than that of the present.展开更多
There are 4 species of Littorinidae on the intertidal hard bed in the Jiulong River Estu-ary. They are Littorina scabra, L. brevicula, Nodilittorina pyramidalis pyramidalis and N.millegrana. Of these species, L. scabr...There are 4 species of Littorinidae on the intertidal hard bed in the Jiulong River Estu-ary. They are Littorina scabra, L. brevicula, Nodilittorina pyramidalis pyramidalis and N.millegrana. Of these species, L. scabra is a dominant species. According to the results of in-vestigation, we find distribution patterns of the Littorinidae on intertidal hard bed in theestuary as follows: (1)There is no Littorinid species at Haicheng Station. (2)There is only Lit-展开更多
Dissolved iodine species and the relationship between its distribution and salinity in Jiulong River estuarine water have been determined. It has been found that the total iodine, iodate and iodide are positive linear...Dissolved iodine species and the relationship between its distribution and salinity in Jiulong River estuarine water have been determined. It has been found that the total iodine, iodate and iodide are positive linear with salinity. This indicates that dissolved iodine species (IO-3 and I- ) in estuarine water .how conservative behaviour. The river water contains 2. 40μg/1 as iodide and less than 1. 0μg/1 as iodate, and iodide is the predominant species. Whereas the sea water contains 39. 4μg/1 as iodate and 4. 00μg/1 as iodide, and iodate is the dominant form. The distribution of dissolved iodine in pore water, as a function of depth, has been studied. Iodine in pore water occurs as iodide. The apparent fluxes of soluble iodine from the sediment to the overlying water in the estuary have been determined. The values are 2. 4 (15℃) and 27μmol/(m2·d) (30℃) respectively.展开更多
Water samples were collected at 20 sites on 4 occasions in 2009(twice in May,and once in both August and November) along the Jiulong River,South China to examine how nutrient inputs from the Jiulong River could affect...Water samples were collected at 20 sites on 4 occasions in 2009(twice in May,and once in both August and November) along the Jiulong River,South China to examine how nutrient inputs from the Jiulong River could affect the nutrient status of the Xiamen Water.Samples were analyzed for nitrite(NO2-N),nitrate(NO3-N),ammonium(NH4-N),phosphate(PO4-P),silicate(SiO3-Si),salinity,and temperature,to determine the nutrient and trophic status of the river.The results indicate that nutrients are derived mainly from river runoff.NO3-N was the main form of DIN in most parts of the river.In addition,NO3-N,DIN,and SiO3-Si behave conservatively.There is a surplus of DIN and SiO3-Si in the river,and PO4-P is a limitation on phytoplankton growth.The concentration of DIN is typically above 0.60 mg/dm3,and higher than 1.00 mg/dm3in most parts of the river.The concentration of PO4-P is typically above 0.02 mg/dm3,while the concentration of SiO3-Si is higher than 1.00 mg/dm3.Between 2003 and 2008,samples were collected 3 times per year(May,August and November) at 27 sites in the Xiamen Water and analyzed for NO2-N,NO3-N,NH4-N,PO4-P,salinity,and temperature.We discovered that the Jiulong River was the key source of DIN into the Xiamen Water,but not PO4-P,indicating the reason of the N/P molar ratio imbalance in the Xiamen Water.In the future,the effects of high DIN concentrations on the phytoplankton communities and marine ecosystems of the Xiamen Water shall be studied.展开更多
Phytoplankton blooms occurring in the Jiangdong Reservoir of Jiulong River,Fujian Province,South China,are a potential source of contamination of the drinking water of Xiamen(Amoy)City.To understand the main factors g...Phytoplankton blooms occurring in the Jiangdong Reservoir of Jiulong River,Fujian Province,South China,are a potential source of contamination of the drinking water of Xiamen(Amoy)City.To understand the main factors governing phytoplankton composition and succession,we sampled phytoplankton and measured environmental parameters in the reservoir,weekly or biweekly from Jan.2010 to Feb.2012.We identifi ed 123 species of phytoplankton from 7 phyla and 74 genera.The major phyla were Chlorophyta,Bacillariophyta,Cryptophyta,Cyanophyta,and Dinophyta.The main trend in the succession of phytoplankton was from prevalence of Cryptophyta-Bacillariophyta communities to those of Chlorophyta-Cyanophyta.High cell concentrations of Cryptophyta,predominantly Komma caudate,Cryptomonas marssonii,and Cryptomonas erosa,were present in winter,associated with low river discharge and cold water.Bacillariophyta,primarily Cyclotella meneghiniana,Aulacoseira granulata,and Aulacoseira granulata var.angustissima,dominated in early spring,coinciding with high turbulence and low irradiance.During early summer and autumn,Chlorophyta,comprising Scenedesmus quadricauda,Dictyosphaerium ehrenbergianum,and Pandorina sp.were prevalent during conditions of warmer water temperatures and low turbulence.Cyanophyta,with dominance of Pseudanabaena mucicola,Merismopedia tenuissima and Raphidiopsis sp.increased throughout the summer,coinciding with higher water temperatures and lower nutrient concentrations.Dinophyta content was occasionally high during winter and summer.Peridiniopsis penardii(Dinophyta)bloomed during winter 2009,with a persistently high biomass recorded into early spring.Canonical correspondence analysis indicated that phytoplankton communities were infl uenced by river discharge,irradiance,water temperature,and nutrient concentrations.展开更多
The isotopic composition of dissolved inorganic carbon(DIC) in estuarine environments has been studied for its significant role in determining the isotopic composition of inorganic/organic matter and its applications ...The isotopic composition of dissolved inorganic carbon(DIC) in estuarine environments has been studied for its significant role in determining the isotopic composition of inorganic/organic matter and its applications to the study of various natural processes. In this paper, based on the stable isotope geochemical characteristics of dissolved inorganic carbon in the Jiulong River Estuary, the following conclusions are drawn:(1) δ13CDIC values are mainly controlled by the mixing ratio of fresh water and sea water;(2) δ13Cphytoplankton values are linearly related to the δ13CDIC values;(3) δ13CPOM values for the Jiulong River Estuary are affected by anthropogenic pollution significantly; and(4) the comprehensive analysis of δ13Cphytoplankton, δ13CPOM and δ13CDIC shows that along with increasing salinity, the proportion of POM derived from the degradation of phytoplanktons gradually increases.展开更多
Mixing of freshwater and seawater creates the well-known salinity gradients along the estuaries. In order to investigate how phytoplankton respond to the acute salinity changes, we exposed natural phytoplankton assemb...Mixing of freshwater and seawater creates the well-known salinity gradients along the estuaries. In order to investigate how phytoplankton respond to the acute salinity changes, we exposed natural phytoplankton assemblies from the Jiulong River Estuary to differential saline field water while continuously monitoring their photosynthetic performances under both indoor-and outdoor-growth conditions. When the natural cell assemblies from salinity 30 field water were exposed to series low saline field water(salinity 25, 17, 13 and 7.5), the effective Photosystem II quantum yield(ΔF/Fm′) decreased sharply, e.g., to one-fifth of its initials after 5 min exposure to salinity 7.5 field water, and then increased fast during the following 40 min and almost completely recovered after 320 min. During such an exposure process, non-photochemical quenching(NPQ) sharply increased from 0 to 0.85 within 5 min, and then decreased to nearly 0 within the following 70 min. When these cells re-acclimated to salinity 7.5 field water were exposed to series high saline field water(salinity 13, 17, 25 and 30), a similar response pattern was observed, with the decreased ΔF/Fm′ accompanied with increased NPQ, and followed by the recovery-induced increase in ΔF/Fm′ and decrease in NPQ. A similar response pattern as ΔF/Fm′to the acute osmotic stress was also observed in the photosynthetic carbon fixation capacity according to radiocarbon(14C) incorporation. Our results indicate that estuarine phytoplankton assemblies could rapidly recover from the acute osmotic stress, implying a potential cause for their frequent blooms in coastal-estuarine waters where despite drastically varying salinity, available nutrients are abundant due to the land-derived runoffs or mixing-caused relaxations from sediments.展开更多
The bottom sediment samples were gathered during island investigation in 1994 and in the period of carrying out the natural science fund project of Fujian in 1999. The composition, distribution and assemblage characte...The bottom sediment samples were gathered during island investigation in 1994 and in the period of carrying out the natural science fund project of Fujian in 1999. The composition, distribution and assemblage characteristics of heavy minerals which granularity distributes from 0.063 to 0.125 mm in the sediment from Jiulong River estuary are studied in the paper. The results show that there are 49 kinds of heavy minerals and the average content of them is 9.38 %. The dominant and characteristic minerals are magnetite, hematite, epidote, ilmenite, limonite, hornblende, zircon, andalusite, biotite and so on. 4 mineral assemblage ⅠⅡzones (.The watercourse gateway of Jiulong River mineral zone, . The northern estuary ⅢⅣof Jiulong River mineral zone, . The southern estuary mineral zone, . The eastern estuary of Jiulong River mineral zone ), can be divided based on the heavy mineral contents and the distribution characteristics, which not only relates to the matter sources but also is controlled by hydrodynamic condition and the sedimentary environment in the Jiulong River estuary.展开更多
The Jiulong River Estuary (JRE) is a typical subtropical macro-tide estuary on the southwest coast of the Taiwan Strait (TWS),which has been greatly impacted by human activities over the past 30 years.To understand nu...The Jiulong River Estuary (JRE) is a typical subtropical macro-tide estuary on the southwest coast of the Taiwan Strait (TWS),which has been greatly impacted by human activities over the past 30 years.To understand nutrient dynamics and fluxes under such a heavy background of anthropogenic perturbation,eight cruises were conducted from April 2008 to April 2011,covering both wet (May to September) and dry (October to April next year) seasons.Nutrient concentrations were very high for the freshwater end-member in the upper reach of the JRE (nitrate (NO 3-N):120-230 mol L-1 ;nitrite (NO 2-N):5-15 mol L-1 ;ammonium (NH 4-N):15-170 mol L-1 ;soluble reactive phosphorus (SRP):1.2-3.5 mol L-1 ;dissolved silicate (DSi):200-340 mol L-1).In dry seasons,concentrations of these nutrients were higher than in wet seasons.Nitrate was the dominant chemical species of dissolved inorganic nitrogen (DIN),with percentages of 67%-96% in wet seasons and 55%-72% in dry seasons.Distributions of NO 3-N and DSi against salinity were nearly constant during all cruises,and showed generally conservative mixing behaviors in the estuary (1<Salinity<32).The concentrations of SRP varied within a narrow range of 1.0-2.0 mol L-1 in low/middle salinity areas,and they were quickly diluted by relatively oligotrophic near-shore seawater in the high salinity region.Based on a temporally high-resolution water discharge dataset,riverine fluxes of DIN,SRP and DSi into the JRE were calculated at 34.3 10 3 t N a 1,0.63 10 3 t P a-1 and 72.7 10 3 t Si a-1,respectively.In comparison,estuarine export fluxes of DIN,SRP and DSi from the JRE to the TWS were estimated at 34.8 10 3 t N a-1,0.82 10 3 t P a-1 and 71.6 10 3 t Si a-1.The estuarine addition flux of SRP was independently estimated at 0.16 10 3 t P a-1.In comparison with major world rivers,the Jiulong River shows a very high areal yield rate of NO 3-N.In comparison with historical datasets from 1980s-1990s,concentrations of NO 3-N and SRP increased 2-3 times in upper/middle areas of the JRE,while DSi remained at the same level.The latter is much different from decadal nutrient changes in the Mississippi River and the Yangtze River/Estuary.Such nutrient changes may fundamentally contribute to recent red tide events in the JRE and adjacent Xiamen Bay.展开更多
文摘The polycyclic aromatic hydrocarbons(PAHs) concentrations were determined in the root of three mangrove species(Kandelia candel, Avicennia marina and Bruguiera gymnorrhiza) and their growing environment(sediment) in mangrove wetlands of Jiulong River Estuary, Fujian, China. The total PAHs(16 parent PAHs) in mangrove sediments ranged from 193.44 to 270.53 ng/g dw, with a mean value of 231.76±31.78 ng/g dw. Compared with other mangrove and coastal marine sediments, the PAHs concentrations of all the sampling areas in this study were at relatively lower level. The total PAHs(13 parent PAHs) values varied from 30.83 to 62.73 ng/g dw in mangrove roots. Benzo[a]pyrene(five-ring), fluoranthene(four-ring) and pyrene(four-ring) dominated in mangrove sediments. Based on ratios of phenathrene/anthracene, fluoranthene/pyrene and fluoranthene/pyrene + fluoranthene, the main possible sources of surface sediment PAHs were identified as grass, wood or coal combustion for mangrove wetlands of Jiulong River Estuary. Naphthalene(two-ring) and phenathrene(three-ring) were the most abundant compounds in mangrove roots. Sediment-to-vegetation bioconcentration factors(BCF SV s) were calculated and their relationships with PAHs' physico-chemical properties were investigated. The average BCF SV s of PAHs for three mangrove species roots were almost all under the level of 1 except for naphthalene. Good linear relationship between BCF SV values for mangrove roots and PAHs water solubility, octanol-water partitioning coefficients was derived in present study. The solubility and the octanol-water partition coefficient were proved to be good predictors for the accumulation of PAHs in mangrove roots, respectively.
文摘Four units and twenty-four zones of diatom have been discerned in the Borehole ZK5 in the estuarine plain of the Jiulong River, Fujian Province. Comprehensive analysis of these, together with microbiological assemblages and age determinations in some other boreholes, shows that during the Late Wurm Glacial, sea level of the study area rose and fell frequently, but had principally been in the environments of estuary-bay. This mainly resulted from the tectonic subouction. In this period 3 low sea levels occurred. at 18, 16 and 12 kaBP respectively. During Holocene, sea weter intruded massively and the sea level over the transgnaion maximum had been 5-10 m higher than that of the present.
文摘There are 4 species of Littorinidae on the intertidal hard bed in the Jiulong River Estu-ary. They are Littorina scabra, L. brevicula, Nodilittorina pyramidalis pyramidalis and N.millegrana. Of these species, L. scabra is a dominant species. According to the results of in-vestigation, we find distribution patterns of the Littorinidae on intertidal hard bed in theestuary as follows: (1)There is no Littorinid species at Haicheng Station. (2)There is only Lit-
文摘Dissolved iodine species and the relationship between its distribution and salinity in Jiulong River estuarine water have been determined. It has been found that the total iodine, iodate and iodide are positive linear with salinity. This indicates that dissolved iodine species (IO-3 and I- ) in estuarine water .how conservative behaviour. The river water contains 2. 40μg/1 as iodide and less than 1. 0μg/1 as iodate, and iodide is the predominant species. Whereas the sea water contains 39. 4μg/1 as iodate and 4. 00μg/1 as iodide, and iodate is the dominant form. The distribution of dissolved iodine in pore water, as a function of depth, has been studied. Iodine in pore water occurs as iodide. The apparent fluxes of soluble iodine from the sediment to the overlying water in the estuary have been determined. The values are 2. 4 (15℃) and 27μmol/(m2·d) (30℃) respectively.
基金Supported by the Scientific Research Foundation of Third Institute of Oceanography,SOA(Nos.TIO2007009,TIO2009007)the River Basin-Estuary Ecological Security Assessment and Management Strategy(No.200805064)+3 种基金the Natural Science Foundation of Fujian Province(Nos.2006J0362,2010J01260,2012Y0048)the National Department Public Benefit Research Foundation:Protection Technique of Beach and Demonstration Project in China(No.200905008)a Sub-task of the National Commonweal Marine Research Project:Typical Semi-enclosed Bay Eutrophication Immediate Report and Ecological Effect Assessment(No.201105014-6)the Special Social Commonweal Foundation for Research Institutes:Primary Red Tide Warning Index System of Physical and Chemical Research for Enclosed Bay(No.2004DIB3J084)
文摘Water samples were collected at 20 sites on 4 occasions in 2009(twice in May,and once in both August and November) along the Jiulong River,South China to examine how nutrient inputs from the Jiulong River could affect the nutrient status of the Xiamen Water.Samples were analyzed for nitrite(NO2-N),nitrate(NO3-N),ammonium(NH4-N),phosphate(PO4-P),silicate(SiO3-Si),salinity,and temperature,to determine the nutrient and trophic status of the river.The results indicate that nutrients are derived mainly from river runoff.NO3-N was the main form of DIN in most parts of the river.In addition,NO3-N,DIN,and SiO3-Si behave conservatively.There is a surplus of DIN and SiO3-Si in the river,and PO4-P is a limitation on phytoplankton growth.The concentration of DIN is typically above 0.60 mg/dm3,and higher than 1.00 mg/dm3in most parts of the river.The concentration of PO4-P is typically above 0.02 mg/dm3,while the concentration of SiO3-Si is higher than 1.00 mg/dm3.Between 2003 and 2008,samples were collected 3 times per year(May,August and November) at 27 sites in the Xiamen Water and analyzed for NO2-N,NO3-N,NH4-N,PO4-P,salinity,and temperature.We discovered that the Jiulong River was the key source of DIN into the Xiamen Water,but not PO4-P,indicating the reason of the N/P molar ratio imbalance in the Xiamen Water.In the future,the effects of high DIN concentrations on the phytoplankton communities and marine ecosystems of the Xiamen Water shall be studied.
基金Supported by the Bureau of Science and Technology of Xiamen Municipal Government,China(No.3502Z20091005)the National Natural Science Foundation of China(No.40925018)the State Oceanic Administration(SOA)Program(Nos.201105021,201005015)
文摘Phytoplankton blooms occurring in the Jiangdong Reservoir of Jiulong River,Fujian Province,South China,are a potential source of contamination of the drinking water of Xiamen(Amoy)City.To understand the main factors governing phytoplankton composition and succession,we sampled phytoplankton and measured environmental parameters in the reservoir,weekly or biweekly from Jan.2010 to Feb.2012.We identifi ed 123 species of phytoplankton from 7 phyla and 74 genera.The major phyla were Chlorophyta,Bacillariophyta,Cryptophyta,Cyanophyta,and Dinophyta.The main trend in the succession of phytoplankton was from prevalence of Cryptophyta-Bacillariophyta communities to those of Chlorophyta-Cyanophyta.High cell concentrations of Cryptophyta,predominantly Komma caudate,Cryptomonas marssonii,and Cryptomonas erosa,were present in winter,associated with low river discharge and cold water.Bacillariophyta,primarily Cyclotella meneghiniana,Aulacoseira granulata,and Aulacoseira granulata var.angustissima,dominated in early spring,coinciding with high turbulence and low irradiance.During early summer and autumn,Chlorophyta,comprising Scenedesmus quadricauda,Dictyosphaerium ehrenbergianum,and Pandorina sp.were prevalent during conditions of warmer water temperatures and low turbulence.Cyanophyta,with dominance of Pseudanabaena mucicola,Merismopedia tenuissima and Raphidiopsis sp.increased throughout the summer,coinciding with higher water temperatures and lower nutrient concentrations.Dinophyta content was occasionally high during winter and summer.Peridiniopsis penardii(Dinophyta)bloomed during winter 2009,with a persistently high biomass recorded into early spring.Canonical correspondence analysis indicated that phytoplankton communities were infl uenced by river discharge,irradiance,water temperature,and nutrient concentrations.
基金financially supported jointly by the National Natural Science Foundation of China(Grant Nos.40771185 and 51004053)the Fujian Province Natural Science Foundation(D0710021)the Li Shangda Scientific Research Foundation of Jimei University,China(No.ZC2011015)
文摘The isotopic composition of dissolved inorganic carbon(DIC) in estuarine environments has been studied for its significant role in determining the isotopic composition of inorganic/organic matter and its applications to the study of various natural processes. In this paper, based on the stable isotope geochemical characteristics of dissolved inorganic carbon in the Jiulong River Estuary, the following conclusions are drawn:(1) δ13CDIC values are mainly controlled by the mixing ratio of fresh water and sea water;(2) δ13Cphytoplankton values are linearly related to the δ13CDIC values;(3) δ13CPOM values for the Jiulong River Estuary are affected by anthropogenic pollution significantly; and(4) the comprehensive analysis of δ13Cphytoplankton, δ13CPOM and δ13CDIC shows that along with increasing salinity, the proportion of POM derived from the degradation of phytoplanktons gradually increases.
基金The National Natural Science Foundation of China under contract Nos 41890853 and 41676156the National Basic Research Program of China(973 Program)under contract No.2015CB452903+3 种基金the Strategic Priority Research Program of Chinese Academy of Sciences under contract Nos XDA13020103 and XDA11020305the Natural Science Foundation of Guangdong Province under contract Nos 2015A030313826 and 2017A030313216the Special Fund for Agro-scientific Research in the Public Interest under contract No.201403008the Science and Technology Planning Project of Guangdong Province under contract No.2017B030314052
文摘Mixing of freshwater and seawater creates the well-known salinity gradients along the estuaries. In order to investigate how phytoplankton respond to the acute salinity changes, we exposed natural phytoplankton assemblies from the Jiulong River Estuary to differential saline field water while continuously monitoring their photosynthetic performances under both indoor-and outdoor-growth conditions. When the natural cell assemblies from salinity 30 field water were exposed to series low saline field water(salinity 25, 17, 13 and 7.5), the effective Photosystem II quantum yield(ΔF/Fm′) decreased sharply, e.g., to one-fifth of its initials after 5 min exposure to salinity 7.5 field water, and then increased fast during the following 40 min and almost completely recovered after 320 min. During such an exposure process, non-photochemical quenching(NPQ) sharply increased from 0 to 0.85 within 5 min, and then decreased to nearly 0 within the following 70 min. When these cells re-acclimated to salinity 7.5 field water were exposed to series high saline field water(salinity 13, 17, 25 and 30), a similar response pattern was observed, with the decreased ΔF/Fm′ accompanied with increased NPQ, and followed by the recovery-induced increase in ΔF/Fm′ and decrease in NPQ. A similar response pattern as ΔF/Fm′to the acute osmotic stress was also observed in the photosynthetic carbon fixation capacity according to radiocarbon(14C) incorporation. Our results indicate that estuarine phytoplankton assemblies could rapidly recover from the acute osmotic stress, implying a potential cause for their frequent blooms in coastal-estuarine waters where despite drastically varying salinity, available nutrients are abundant due to the land-derived runoffs or mixing-caused relaxations from sediments.
基金The natural science fund of Fujian ( Numbering item: D9910006 )
文摘The bottom sediment samples were gathered during island investigation in 1994 and in the period of carrying out the natural science fund project of Fujian in 1999. The composition, distribution and assemblage characteristics of heavy minerals which granularity distributes from 0.063 to 0.125 mm in the sediment from Jiulong River estuary are studied in the paper. The results show that there are 49 kinds of heavy minerals and the average content of them is 9.38 %. The dominant and characteristic minerals are magnetite, hematite, epidote, ilmenite, limonite, hornblende, zircon, andalusite, biotite and so on. 4 mineral assemblage ⅠⅡzones (.The watercourse gateway of Jiulong River mineral zone, . The northern estuary ⅢⅣof Jiulong River mineral zone, . The southern estuary mineral zone, . The eastern estuary of Jiulong River mineral zone ), can be divided based on the heavy mineral contents and the distribution characteristics, which not only relates to the matter sources but also is controlled by hydrodynamic condition and the sedimentary environment in the Jiulong River estuary.
基金supported by the National Natural Science Founda-tion of China(NSFC)(40810069004)the National Basic Research Program of China(2009CB421204)+1 种基金Sampling cruises were partially supported by the State Oceanic Administration of China(contract DOMEP-MEA-01-10)the NSFC(40949901)
文摘The Jiulong River Estuary (JRE) is a typical subtropical macro-tide estuary on the southwest coast of the Taiwan Strait (TWS),which has been greatly impacted by human activities over the past 30 years.To understand nutrient dynamics and fluxes under such a heavy background of anthropogenic perturbation,eight cruises were conducted from April 2008 to April 2011,covering both wet (May to September) and dry (October to April next year) seasons.Nutrient concentrations were very high for the freshwater end-member in the upper reach of the JRE (nitrate (NO 3-N):120-230 mol L-1 ;nitrite (NO 2-N):5-15 mol L-1 ;ammonium (NH 4-N):15-170 mol L-1 ;soluble reactive phosphorus (SRP):1.2-3.5 mol L-1 ;dissolved silicate (DSi):200-340 mol L-1).In dry seasons,concentrations of these nutrients were higher than in wet seasons.Nitrate was the dominant chemical species of dissolved inorganic nitrogen (DIN),with percentages of 67%-96% in wet seasons and 55%-72% in dry seasons.Distributions of NO 3-N and DSi against salinity were nearly constant during all cruises,and showed generally conservative mixing behaviors in the estuary (1<Salinity<32).The concentrations of SRP varied within a narrow range of 1.0-2.0 mol L-1 in low/middle salinity areas,and they were quickly diluted by relatively oligotrophic near-shore seawater in the high salinity region.Based on a temporally high-resolution water discharge dataset,riverine fluxes of DIN,SRP and DSi into the JRE were calculated at 34.3 10 3 t N a 1,0.63 10 3 t P a-1 and 72.7 10 3 t Si a-1,respectively.In comparison,estuarine export fluxes of DIN,SRP and DSi from the JRE to the TWS were estimated at 34.8 10 3 t N a-1,0.82 10 3 t P a-1 and 71.6 10 3 t Si a-1.The estuarine addition flux of SRP was independently estimated at 0.16 10 3 t P a-1.In comparison with major world rivers,the Jiulong River shows a very high areal yield rate of NO 3-N.In comparison with historical datasets from 1980s-1990s,concentrations of NO 3-N and SRP increased 2-3 times in upper/middle areas of the JRE,while DSi remained at the same level.The latter is much different from decadal nutrient changes in the Mississippi River and the Yangtze River/Estuary.Such nutrient changes may fundamentally contribute to recent red tide events in the JRE and adjacent Xiamen Bay.