Parent and alkylated polycyclic aromatic hydrocarbons(alkyl-PAHs),which are a class of important toxic components of crude oil especially in the marine environment,exhibit adverse effects on aquatic life and potential...Parent and alkylated polycyclic aromatic hydrocarbons(alkyl-PAHs),which are a class of important toxic components of crude oil especially in the marine environment,exhibit adverse effects on aquatic life and potentially pose a human health risk.However,the lack of chronic toxicity data is one of the hindrances for alkylPAHs when assessing their ecological risks.In this study,predicted no-effect concentrations(PNECs)in seawater and marine sediment for ten parent-and alkyl-PAHs were derived by applying species sensitivity distributions(SSDs)and quantitative structure-activity relationships(QSARs).The local area,Dalian Bay,where an oil-spilled accident happened in 2010,was chosen as a case site to assess ecological risks for ten PAHs in surface seawaters and marine sediments.Their PNECs in seawater and sediment for protecting aquatic organisms in marine ecosystems were calculated and recommended in the range of 0.012-2.79μg/L and 48.2-1337 ng/g(dry weight),respectively.Overall,the derived PNECs for the studied PAHs in seawater and marine sediment were comparable to those obtained by classical methods.Risk quotient results indicate low ecological risks to ecosystems for ten parent-and alkyl-PAHs in surface seawaters and surface sediments from the Dalian Bay.These findings provide a first insight into the PNECs and ecological risks of alkyl-PAHs,emphasizing the role of the computational toxicology in ecological risk assessments.The use of QSARs has been identified as a valuable tool for preliminarily assessing ecological risks of emerging pollutants,being more predictable of real exposure scenarios for risk assessment purposes.展开更多
Predicted no-effect concentration(PNEC) is often used in ecological risk assessment to determine low-risk concentrations for chemicals. In the present study, the chronic data from native saltwater species were used to...Predicted no-effect concentration(PNEC) is often used in ecological risk assessment to determine low-risk concentrations for chemicals. In the present study, the chronic data from native saltwater species were used to calculated PNEC values using four methods: log-normal distribution(ETX 2.0), log-triangle distribution(US EPA's water quality criteria procedure), burr III distribution(Burrli OZ) and traditional assessment factor(AF). The PNECs that were calculated using four methods ranged from 0.08 μg/L to 1.8 μg/L. Three of the SSD-derived PNECs range from 0.94 to 1.8 μg/L, about a factor of two apart. To demonstrate the use of SSD-based PNEC values and comprehensively estimate the regional ecological risk for cadmium in surface water of the Bohai Sea, in the Liaodong Bay, Bohai Bay, and Laizhou Bay, China, the dissolved cadmium concentrations were measured and obtained 753 valid data covering 190 stations from July 2006 to November 2007. Based on three ecological risk assessment approaches, namely hazard quotient(HQ), probabilistic risk quotient and joint probability curve(JPC), the potential ecological risk of cadmium in surface water of the Liaodong Bay, Bohai Bay, and Laizahou Bay were estimated. Overall, the ecological risk of cadmium to aquatic ecosystem in the whole Bohai Sea was at acceptable ecological risk level, the order of ecological risk was Liaodong Bay>Bohai Bay>Laizhou Bay. However, more concerns should be paid to aquatic ecological risk in the Liaodong Bay which is the home of many steel, metallurgy and petrochemical industrial in China.展开更多
The phytoplankton water samples were collected in two multidisciplinary investigations which were carried out during summer(June) and autumn(November to December) of 2011. Phytoplankton species composition and abundan...The phytoplankton water samples were collected in two multidisciplinary investigations which were carried out during summer(June) and autumn(November to December) of 2011. Phytoplankton species composition and abundance data were accomplished by Uterm?hl method. The phytoplankton community was dominated by diatoms and dinoflagellates in the southern Yellow Sea(YS) in summer and autumn. In summer, Paralia sulcata and Prorocentrum dentatum were the predominated species, the cell abundance ranged from 0.074 to 107.733×103 cells/L with an average of 9.057×103 cells/L. Two phytoplankton high abundance appeared in northwest part of the survey area and the Changjiang River Estuary, respectively. In autumn, Par. sulcata became the predominant species, and the phytoplankton cell abundance ranged from 1.035×103 to 8.985×103 cells/L, the average was 3.263×103 cells/L. The phytoplankton abundance in surface layer presented the homogeneous distributions. Canonical Correspondence Analysis(CCA) method was applied for discovering the relationship between environmental factors and the common found phytoplankton species. The responses of phytoplankton to nutrients were varied between summer and autumn. The abundance of most predominant species, Par. sulcata was strongly correlated to temperature and salinity in autumn, but not the case in summer.展开更多
Although the Indo-Australian plate near the Ninetyeast Ridge is important for understanding the formation of new plate boundaries, its tectonic problems are complex and most of them are poorly known. This paper made a...Although the Indo-Australian plate near the Ninetyeast Ridge is important for understanding the formation of new plate boundaries, its tectonic problems are complex and most of them are poorly known. This paper made a detailed tectonic analysis based on the data of bathymetry, gravity and magnetics. Bathymetry and gravity maps show morphological features of many folds, which are related to the intraplate deformation of the Indo-Australian plate due to the collision between the Indian and Asian plates. Gravity anomalies show the structure of fracture zones, which are caused by the seafloor spreading and transform faulting. The characteristics of the folds and fracture zones are consistent with the hypothesis that diffuse plate boundaries and redefined plate components would occur within the Indo-Australian plate. In addition, compiled magnetic data demonstrate magnetic lineations, abandoned spreading centers, southward ridge jumps and plate motions. These features provide useful information for rebuilding the tectonic evolution history of the study area. Magnetic anomalies suggest that an additional plate boundary of transform fault type is developing.展开更多
Dissolved oxygen(DO) and pH in the central part of the Bohai Sea were surveyed in late June and late August,2011.During the June cruise,the bottom DO was in the range of 215-290 μmol-O2 kg-1(i.e.85%-115% of the satur...Dissolved oxygen(DO) and pH in the central part of the Bohai Sea were surveyed in late June and late August,2011.During the June cruise,the bottom DO was in the range of 215-290 μmol-O2 kg-1(i.e.85%-115% of the saturation level),and the bottom pH was in the range of 7.82-8.04 on the total-hydrogen-ion scale.In August,however,both the bottom DO and the pH had significantly declined in the northwestern-northern near-shore areas,where the water depth was no more than 35 m.The lowest bottom DO was 100-110 μmol-O2 kg-1(only 44%-47% of the June DO values) in the northern near-shore area,where the bottom pH was 7.64-7.68 on the total-hydrogen-ion scale(0.16-0.20 units lower than the June pH value).The largest decreases in DO and in pH were observed in the northwestern near-shore bottom waters,corresponding to declines of 170 μmol-O2 kg-1(as high as 59% of the June DO value) and 0.29 pH units,respectively.The greatest pH decline of 0.29 pH units meant that the total-hydrogen-ion concentration doubled in the bottom waters from June to August.Based on field measurements of bottom DO/pH combined with a simplified model simulation,we suggest that respiration/remineralization-derived CO2 increased the acidity in the bottom oxygen-depleted waters of northwestern-northern near-shore areas in the Bohai Sea as a result of coastal red tides and/or marine aquaculture.This aquatic chemistry is suggested to be partially responsible for scallop-breeding failures in the northwestern Bohai Sea in summer 2011.展开更多
Recent geophysical research programs survey the Tamu Massif within the Shatsky Rise oceanic plateau in the northwest Pacific Ocean to understand the formation of this immense volcano and to test the formation hypothes...Recent geophysical research programs survey the Tamu Massif within the Shatsky Rise oceanic plateau in the northwest Pacific Ocean to understand the formation of this immense volcano and to test the formation hypotheses of large igneous province volcanism. Massive sheet basalt flows are cored from the Tamu Massif, implying voluminous eruptions with high effusion rates. Seismic reflection data show that the Tamu Massif is the largest single volcano on Earth, characterized by a central volcanic shield with lowgradient flank slopes, implying lava flows emanating from its center and spreading massive area on the seafloor. Velocity model calculated from seismic refraction data shows that crustal thickness has a negative correlation with average velocity, implying a chemically anomalous origin of the Tamu Massif. Seismic refraction and reflection data reveal a complete crustal structure across the entire volcano, featured by a deep crust root with a maximum thickness of $30 km, and Moho geometry is consistent with the Airy Isostasy. These recent findings provide evidence for the two end-member formation models: the mantle plume and the plate boundary. Both are supported by some results, but both are not fit with some either. Consequently, plume–ridge interaction could be a resolution that awaits future investigations.展开更多
The production and application of organophosphate esters(OPEs)have dramatically increased in recent years due to their use as a replacement for brominated flame retardants.In this study,13 OPEs(∑_(13)OPEs)were analyz...The production and application of organophosphate esters(OPEs)have dramatically increased in recent years due to their use as a replacement for brominated flame retardants.In this study,13 OPEs(∑_(13)OPEs)were analyzed in indoor air samples from kitchens and living rooms in 14 residential homes in Beijing,China.The concentrations of ∑_(13)OPEs in kitchen air samples(mean:13 ng/m^(3))were significantly(p<0.05)higher than in living room air samples(5.0 ng/m^(3)).In addition,paired window surface organic film samples were collected and analyzed to investigate film-air partitioning,exhibiting a mean concentration of ∑_(13)OPEs of 4100 ng/m^(2).The congener profiles showed that tris(2-chloroisopropyl)phosphate(TCPP)was the predominant compound in both window film samples(48%)and the corresponding indoor air sample(56%).The estimated daily intakes(EDI)of OPEs via indoor air inhalation were 2.8 and 1.4 ng/kg/day for infants and adults,respectively,both of which are below the reference dose values(RfDs).Overall,these findings indicate that OPEs in the indoor air environment of residential homes in Beijing are not likely to pose a health risk to the general population.展开更多
This study developed a method to perform the simultaneous concentration and selective separation of66(ultra) trace persistent toxic substances in Antarctic waters. The substances included 30 polychlorinated biphenyls,...This study developed a method to perform the simultaneous concentration and selective separation of66(ultra) trace persistent toxic substances in Antarctic waters. The substances included 30 polychlorinated biphenyls, 17 organochlorine pesticides, 16 polycyclic aromatic hydrocarbons, 3hexabromocyclododecanes. Solid phase extraction was performed using a C18 membrane and silica gel column. Gradient elution was conducted using organic solvents with different polarities; as a result, the efficiency of the C18 film is improved and the interferences from impurities and target compounds are eliminated. Extracts were subsequently analyzed through gas chromatography or liquid and gas chromatography coupled to tandem mass spectrometry. Method validation yielded the following values:recoveries of all target analytes in the Antarctic water ranged from 87.3% to 117.6% and reproducibility as percent relative standard deviation was lower than 5%. Quantification limits ranged from 0.004 mg L 1[2_TD$IF]to0.030 mg L 1. The established method improved the recoveries and reduced the limits of detection.Results indicated the method exhibited good performance in the simultaneous concentration and selective separation of 66(ultra) trace organic pollutants; Therefore, the proposed sample pretreatment can potentially eliminate the effects of various classes of impurities to some extent.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
Polycyclic aromatic hydrocarbons (PAHs) investigation in different matrices has been reported largely,whereas reports on snow samples were limited.Snow,as the main matrix in the polar region,has an important study mea...Polycyclic aromatic hydrocarbons (PAHs) investigation in different matrices has been reported largely,whereas reports on snow samples were limited.Snow,as the main matrix in the polar region,has an important study meaning.PAHs in snow samples were analyzed to investigate the distribution and contamination status of them in the Antarctic,as well as to provide some references for global migration of PAHs.Snow samples collected in Fildes Peninsula were enriched and separated by solid-phase membrane disks and eluted by methylene dichloride,then quantified by gas chromatography/mass spectrometry.All types of PAHs were detected except for Benzo(a)pyrene.Principal component analysis method was applied to characterize them.Three factors (Naphthalene,Fluorene and Phenanthrene) accounted for 60.57%,21.61% and 9.80%,respectively.The results showed that the major PAHs sources maybe the atmospheric transportation,and the combustion of fuel in Fildes Peninsula.The comparison of concentration and types of PAHs between accumulated snow and fresh snow showed that the main compound concentrations in accumulated snow samples were higher than those in fresh ones.The risk assessment indicated that the amount of PAHs in the snow samples would not lead to ecological risk.展开更多
Concentrations of 16 polybrominated diphenyl ether(PBDE) congeners were measured in river sediments, paddy soils and three species of paddy-field organisms(crab, loach and carp) collected from the Liaohe River Basin, ...Concentrations of 16 polybrominated diphenyl ether(PBDE) congeners were measured in river sediments, paddy soils and three species of paddy-field organisms(crab, loach and carp) collected from the Liaohe River Basin, northeastern China. The total contents of PBDEs(∑_(16)PBDEs) in sediments and paddy soils were in the ranges of 273.4–3246.3 pg/g dry weight(dw), and 192.1–1783.8 pg/g dw, respectively. BDE 209 was the dominant congener both in sediments and paddy soils. The concentrations of ∑_(16)PBDEs in sediments were significantly higher than those in the adjacent paddy soils, indicating a potential transport of PBDEs from river to paddy ecosystems via river water irrigation. The biota–soil accumulation factor(BSAF) was calculated as the ratio between the lipid-normalized concentration in paddyfield organisms and the total organic carbon-normalized concentration in paddy soil. The average BSAF values of ∑15PBDEs followed the sequence of crab(3.6) > loach(3.3) > carp(2.1). BDE 154 had the highest BSAF value, and a parabolic trend between BSAF values of individual PBDE congeners and their log KOWvalues was observed. In view of the fact that crab had the larger BSAF value and higher lipid content, the ecological risk and health risk for crab cultivation in paddy fields should be of particular concern.展开更多
In recent years, Dechloranes have been widely detected in the environment around the world.However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic,remain lacking. Therefore, the conce...In recent years, Dechloranes have been widely detected in the environment around the world.However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic,remain lacking. Therefore, the concentrations of 5 Dechloranes in surface seawater, sediment,soil, moss, and dung collected from Ny-lesund in the Arctic were measured with the concentrations 93 pg/L, 342, 325, 1.4, and 258 pg/g, respectively, which were much lower than those in Asian and European regions. The mean ratios of anti-Dechlorane Plus(DP) to total DP(fanti) in seawater, sediment, soil, moss, dung, and atmospheric samples were 0.36, 0.21, 0.18,0.27, 0.66, and 0.43, respectively. Results suggested that the main source of DP in seawater,sediment, soil, and moss was long-range atmospheric transport. However, the ratio identified in dung was different, for which the migration behavior of the organism is probably the main source of DP.展开更多
Sediment is recognized as the largest reservoir and source of methane(CH_(4))in the ocean,especially in the shallow coastal areas.To date,few data of CH_(4)concentration in sediment have been reported in the China she...Sediment is recognized as the largest reservoir and source of methane(CH_(4))in the ocean,especially in the shallow coastal areas.To date,few data of CH_(4)concentration in sediment have been reported in the China shelf seas.In this study,we measured CH_(4)concentration in sediment and overlying seawater columns,and conducted an incubation experiment in the Bohai Sea in May 2017.CH_(4)concentration was found to be ranged from 3.075 to 1.795μmol/L in sediment,which was 2 to 3 orders of magnitude higher than that in overlying seawater columns.The surface sediment was an important source of CH_(4),while bottom seawater acted as its sink.Furthermore,the net emission rate via sediment water interface(SWI)was calculated as 2.45μmol/(m^(2)·day)based on the incubation experiment at station73,and the earthquake may enhance CH_(4)release from sediment to seawater column in the eastern Bohai Sea.展开更多
Lidar techniques present a distinctive ability to resolve vertical structure of optical properties within the upper water column at both day-and night-time.However,accuracy challenges remain for existing lidar instrum...Lidar techniques present a distinctive ability to resolve vertical structure of optical properties within the upper water column at both day-and night-time.However,accuracy challenges remain for existing lidar instruments due to the ill-posed nature of elastic backscatter lidar retrievals and multiple scattering.Here we demonstrate the high performance of,to the best of our knowledge,the first shipborne oceanic high-spectral-resolution lidar(HSRL)and illustrate a multiple scattering correction algorithm to rigorously address the above challenges in estimating the depth-resolved diffuse attenuation coefficient Kd and the particulate backscattering coefficient bbp at 532 nm.HSRL data were collected during day-and night-time within the coastal areas of East China Sea and South China Sea,which are connected by the Taiwan Strait.Results include vertical profiles from open ocean waters to moderate turbid waters and first lidar continuous observation of diel vertical distribution of thin layers at a fixed station.The root-mean-square relative differences between the HSRL and coincident in situ measurements are 5.6%and 9.1%for Kd and bbp,respectively,corresponding to an improvement of 2.7-13.5 and 4.9-44.1 times,respectively,with respect to elastic backscatter lidar methods.Shipborne oceanic HSRLs with high performance are expected to be of paramount importance for the construction of 3D map of ocean ecosystem.展开更多
基金The National Key Research and Development Program of China under contract No.2016YFC1402305the Postdoctoral Research Foundation of China under contract No.2016M601148the Scientific Research Special Fund of Marine Public Welfare Industry under contract No.201305002
文摘Parent and alkylated polycyclic aromatic hydrocarbons(alkyl-PAHs),which are a class of important toxic components of crude oil especially in the marine environment,exhibit adverse effects on aquatic life and potentially pose a human health risk.However,the lack of chronic toxicity data is one of the hindrances for alkylPAHs when assessing their ecological risks.In this study,predicted no-effect concentrations(PNECs)in seawater and marine sediment for ten parent-and alkyl-PAHs were derived by applying species sensitivity distributions(SSDs)and quantitative structure-activity relationships(QSARs).The local area,Dalian Bay,where an oil-spilled accident happened in 2010,was chosen as a case site to assess ecological risks for ten PAHs in surface seawaters and marine sediments.Their PNECs in seawater and sediment for protecting aquatic organisms in marine ecosystems were calculated and recommended in the range of 0.012-2.79μg/L and 48.2-1337 ng/g(dry weight),respectively.Overall,the derived PNECs for the studied PAHs in seawater and marine sediment were comparable to those obtained by classical methods.Risk quotient results indicate low ecological risks to ecosystems for ten parent-and alkyl-PAHs in surface seawaters and surface sediments from the Dalian Bay.These findings provide a first insight into the PNECs and ecological risks of alkyl-PAHs,emphasizing the role of the computational toxicology in ecological risk assessments.The use of QSARs has been identified as a valuable tool for preliminarily assessing ecological risks of emerging pollutants,being more predictable of real exposure scenarios for risk assessment purposes.
基金The National Natural Science Foundation of China under contract No.41106089the National Key Technology Research and Development Program of the Ministry of Science and Technology of China under contract No.2010BAC69B01the Scientific Research Special Fund of Marine Public Welfare Industry under contract No.201005008-1
文摘Predicted no-effect concentration(PNEC) is often used in ecological risk assessment to determine low-risk concentrations for chemicals. In the present study, the chronic data from native saltwater species were used to calculated PNEC values using four methods: log-normal distribution(ETX 2.0), log-triangle distribution(US EPA's water quality criteria procedure), burr III distribution(Burrli OZ) and traditional assessment factor(AF). The PNECs that were calculated using four methods ranged from 0.08 μg/L to 1.8 μg/L. Three of the SSD-derived PNECs range from 0.94 to 1.8 μg/L, about a factor of two apart. To demonstrate the use of SSD-based PNEC values and comprehensively estimate the regional ecological risk for cadmium in surface water of the Bohai Sea, in the Liaodong Bay, Bohai Bay, and Laizhou Bay, China, the dissolved cadmium concentrations were measured and obtained 753 valid data covering 190 stations from July 2006 to November 2007. Based on three ecological risk assessment approaches, namely hazard quotient(HQ), probabilistic risk quotient and joint probability curve(JPC), the potential ecological risk of cadmium in surface water of the Liaodong Bay, Bohai Bay, and Laizahou Bay were estimated. Overall, the ecological risk of cadmium to aquatic ecosystem in the whole Bohai Sea was at acceptable ecological risk level, the order of ecological risk was Liaodong Bay>Bohai Bay>Laizhou Bay. However, more concerns should be paid to aquatic ecological risk in the Liaodong Bay which is the home of many steel, metallurgy and petrochemical industrial in China.
基金The Ocean Public Welfare Scientific Research Project under contract Nos 201105021-03 and 201005015-1the New Century Excellent Talents in University under contract No.NCET-12-1065the National Natural Science Foundation of China under contract Nos 41176-136,41276124,40776093,40676089 and NORC2011-01
文摘The phytoplankton water samples were collected in two multidisciplinary investigations which were carried out during summer(June) and autumn(November to December) of 2011. Phytoplankton species composition and abundance data were accomplished by Uterm?hl method. The phytoplankton community was dominated by diatoms and dinoflagellates in the southern Yellow Sea(YS) in summer and autumn. In summer, Paralia sulcata and Prorocentrum dentatum were the predominated species, the cell abundance ranged from 0.074 to 107.733×103 cells/L with an average of 9.057×103 cells/L. Two phytoplankton high abundance appeared in northwest part of the survey area and the Changjiang River Estuary, respectively. In autumn, Par. sulcata became the predominant species, and the phytoplankton cell abundance ranged from 1.035×103 to 8.985×103 cells/L, the average was 3.263×103 cells/L. The phytoplankton abundance in surface layer presented the homogeneous distributions. Canonical Correspondence Analysis(CCA) method was applied for discovering the relationship between environmental factors and the common found phytoplankton species. The responses of phytoplankton to nutrients were varied between summer and autumn. The abundance of most predominant species, Par. sulcata was strongly correlated to temperature and salinity in autumn, but not the case in summer.
基金supported by the National Natural Science Foundation of China(No.41406088)The open fund of Key Laboratory for Ecological Environment in Coastal Areas,State Oceanic Administration(201506)
基金supported by the National Natural Science Foundation of China (Nos. 41606069 and 31500411)the Key Laboratory of Marginal Sea Geology, Chinese Academy of Sciences (MSGL15-04)+6 种基金the Key Laboratory of Marine Mineral Resources, Ministry of Land and Resources of China (No. KLMMR-2014-B-06)the Natural Science Foundation of Guangdong Province in China (No. 2015A030310374)the Director Grant for Oceanic technology of South China Sea Branch, State Oceanic Administration (1501)the Ministry of Human Resources and Social Security of China (50603-54)the Key Laboratory of Integrated Marine Monitoring and Applied Technologies for Harmful Algal Blooms, State Oceanic Administration (No. MATHAB201501)the Key Laboratory for Ecological Environment in Coastal Areas, State Oceanic Administration (201504)the Mariana Trench Project of the South China Sea Institute of Oceanology, Chinese Academy of Sciences
文摘Although the Indo-Australian plate near the Ninetyeast Ridge is important for understanding the formation of new plate boundaries, its tectonic problems are complex and most of them are poorly known. This paper made a detailed tectonic analysis based on the data of bathymetry, gravity and magnetics. Bathymetry and gravity maps show morphological features of many folds, which are related to the intraplate deformation of the Indo-Australian plate due to the collision between the Indian and Asian plates. Gravity anomalies show the structure of fracture zones, which are caused by the seafloor spreading and transform faulting. The characteristics of the folds and fracture zones are consistent with the hypothesis that diffuse plate boundaries and redefined plate components would occur within the Indo-Australian plate. In addition, compiled magnetic data demonstrate magnetic lineations, abandoned spreading centers, southward ridge jumps and plate motions. These features provide useful information for rebuilding the tectonic evolution history of the study area. Magnetic anomalies suggest that an additional plate boundary of transform fault type is developing.
基金supported by the National Basic Research Program of China (2009CB421204)the National Natural Science Foundation of China (NSFC) (41076044 and 40876040)+1 种基金supported by the NSFC (41049901)the State Oceanic Administration of China (contract DOMEP-MEA-01-10)
文摘Dissolved oxygen(DO) and pH in the central part of the Bohai Sea were surveyed in late June and late August,2011.During the June cruise,the bottom DO was in the range of 215-290 μmol-O2 kg-1(i.e.85%-115% of the saturation level),and the bottom pH was in the range of 7.82-8.04 on the total-hydrogen-ion scale.In August,however,both the bottom DO and the pH had significantly declined in the northwestern-northern near-shore areas,where the water depth was no more than 35 m.The lowest bottom DO was 100-110 μmol-O2 kg-1(only 44%-47% of the June DO values) in the northern near-shore area,where the bottom pH was 7.64-7.68 on the total-hydrogen-ion scale(0.16-0.20 units lower than the June pH value).The largest decreases in DO and in pH were observed in the northwestern near-shore bottom waters,corresponding to declines of 170 μmol-O2 kg-1(as high as 59% of the June DO value) and 0.29 pH units,respectively.The greatest pH decline of 0.29 pH units meant that the total-hydrogen-ion concentration doubled in the bottom waters from June to August.Based on field measurements of bottom DO/pH combined with a simplified model simulation,we suggest that respiration/remineralization-derived CO2 increased the acidity in the bottom oxygen-depleted waters of northwestern-northern near-shore areas in the Bohai Sea as a result of coastal red tides and/or marine aquaculture.This aquatic chemistry is suggested to be partially responsible for scallop-breeding failures in the northwestern Bohai Sea in summer 2011.
基金supported by the National Natural Science Foundation of China (41606069 and 31500411)the Key Laboratory of Marine Mineral Resources, Ministry of Land and Resources of China (KLMMR-2014-B-06)+6 种基金the Key Laboratory of Marginal Sea Geology, Chinese Academy of Sciences (MSGL15-04)the Natural Science Foundation of Guangdong Province in China (2015A030310374)the Ministry of Human Resources and Social Security of China (50603-54)the Key Laboratory for Ecological Environment in Coastal Areas, State Oceanic Administration (201504)the Key Laboratory of Integrated Marine Monitoring and Applied Technologies for Harmful Algal Blooms, State Oceanic Administration (MATHAB201501)the Director Grant for Oceanic technology of South China Sea Branch, State Oceanic Administration (1501)the Mariana Trench Project of the South China Sea Institute of Oceanology, Chinese Academy of Sciences
文摘Recent geophysical research programs survey the Tamu Massif within the Shatsky Rise oceanic plateau in the northwest Pacific Ocean to understand the formation of this immense volcano and to test the formation hypotheses of large igneous province volcanism. Massive sheet basalt flows are cored from the Tamu Massif, implying voluminous eruptions with high effusion rates. Seismic reflection data show that the Tamu Massif is the largest single volcano on Earth, characterized by a central volcanic shield with lowgradient flank slopes, implying lava flows emanating from its center and spreading massive area on the seafloor. Velocity model calculated from seismic refraction data shows that crustal thickness has a negative correlation with average velocity, implying a chemically anomalous origin of the Tamu Massif. Seismic refraction and reflection data reveal a complete crustal structure across the entire volcano, featured by a deep crust root with a maximum thickness of $30 km, and Moho geometry is consistent with the Airy Isostasy. These recent findings provide evidence for the two end-member formation models: the mantle plume and the plate boundary. Both are supported by some results, but both are not fit with some either. Consequently, plume–ridge interaction could be a resolution that awaits future investigations.
基金This work was supported by the National Key Research and Development Program,China(No.2018YFC0213103)the National Natural Science Foundation of China(Nos.22021003,21625702).
文摘The production and application of organophosphate esters(OPEs)have dramatically increased in recent years due to their use as a replacement for brominated flame retardants.In this study,13 OPEs(∑_(13)OPEs)were analyzed in indoor air samples from kitchens and living rooms in 14 residential homes in Beijing,China.The concentrations of ∑_(13)OPEs in kitchen air samples(mean:13 ng/m^(3))were significantly(p<0.05)higher than in living room air samples(5.0 ng/m^(3)).In addition,paired window surface organic film samples were collected and analyzed to investigate film-air partitioning,exhibiting a mean concentration of ∑_(13)OPEs of 4100 ng/m^(2).The congener profiles showed that tris(2-chloroisopropyl)phosphate(TCPP)was the predominant compound in both window film samples(48%)and the corresponding indoor air sample(56%).The estimated daily intakes(EDI)of OPEs via indoor air inhalation were 2.8 and 1.4 ng/kg/day for infants and adults,respectively,both of which are below the reference dose values(RfDs).Overall,these findings indicate that OPEs in the indoor air environment of residential homes in Beijing are not likely to pose a health risk to the general population.
基金financially supported by the National Natural Science Foundation of China(No.21377032)the Chinese Polar Environment Comprehensive Investigation and Assessment Program(Nos.2014-02-01,2014-03-04,2014-04-01,2014-04-03)+1 种基金the Marine Public Welfare Scientific Research Projects(No.201105013)the Foundation of Polar Science Key Laboratory,SOA,China(No.KP201208)
文摘This study developed a method to perform the simultaneous concentration and selective separation of66(ultra) trace persistent toxic substances in Antarctic waters. The substances included 30 polychlorinated biphenyls, 17 organochlorine pesticides, 16 polycyclic aromatic hydrocarbons, 3hexabromocyclododecanes. Solid phase extraction was performed using a C18 membrane and silica gel column. Gradient elution was conducted using organic solvents with different polarities; as a result, the efficiency of the C18 film is improved and the interferences from impurities and target compounds are eliminated. Extracts were subsequently analyzed through gas chromatography or liquid and gas chromatography coupled to tandem mass spectrometry. Method validation yielded the following values:recoveries of all target analytes in the Antarctic water ranged from 87.3% to 117.6% and reproducibility as percent relative standard deviation was lower than 5%. Quantification limits ranged from 0.004 mg L 1[2_TD$IF]to0.030 mg L 1. The established method improved the recoveries and reduced the limits of detection.Results indicated the method exhibited good performance in the simultaneous concentration and selective separation of 66(ultra) trace organic pollutants; Therefore, the proposed sample pretreatment can potentially eliminate the effects of various classes of impurities to some extent.
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.
基金supported by the State Ocean Administration Young Scientists Research Program of China (No.2009507)the China Marine Public-welfare Program (No.200805095,201105013)
文摘Polycyclic aromatic hydrocarbons (PAHs) investigation in different matrices has been reported largely,whereas reports on snow samples were limited.Snow,as the main matrix in the polar region,has an important study meaning.PAHs in snow samples were analyzed to investigate the distribution and contamination status of them in the Antarctic,as well as to provide some references for global migration of PAHs.Snow samples collected in Fildes Peninsula were enriched and separated by solid-phase membrane disks and eluted by methylene dichloride,then quantified by gas chromatography/mass spectrometry.All types of PAHs were detected except for Benzo(a)pyrene.Principal component analysis method was applied to characterize them.Three factors (Naphthalene,Fluorene and Phenanthrene) accounted for 60.57%,21.61% and 9.80%,respectively.The results showed that the major PAHs sources maybe the atmospheric transportation,and the combustion of fuel in Fildes Peninsula.The comparison of concentration and types of PAHs between accumulated snow and fresh snow showed that the main compound concentrations in accumulated snow samples were higher than those in fresh ones.The risk assessment indicated that the amount of PAHs in the snow samples would not lead to ecological risk.
基金supported by the Chinese Public Welfare Projects on Environmental Protection (No. 201309030)the National Natural Science Foundation of China (Nos. 21077102 and 41201491)
文摘Concentrations of 16 polybrominated diphenyl ether(PBDE) congeners were measured in river sediments, paddy soils and three species of paddy-field organisms(crab, loach and carp) collected from the Liaohe River Basin, northeastern China. The total contents of PBDEs(∑_(16)PBDEs) in sediments and paddy soils were in the ranges of 273.4–3246.3 pg/g dry weight(dw), and 192.1–1783.8 pg/g dw, respectively. BDE 209 was the dominant congener both in sediments and paddy soils. The concentrations of ∑_(16)PBDEs in sediments were significantly higher than those in the adjacent paddy soils, indicating a potential transport of PBDEs from river to paddy ecosystems via river water irrigation. The biota–soil accumulation factor(BSAF) was calculated as the ratio between the lipid-normalized concentration in paddyfield organisms and the total organic carbon-normalized concentration in paddy soil. The average BSAF values of ∑15PBDEs followed the sequence of crab(3.6) > loach(3.3) > carp(2.1). BDE 154 had the highest BSAF value, and a parabolic trend between BSAF values of individual PBDE congeners and their log KOWvalues was observed. In view of the fact that crab had the larger BSAF value and higher lipid content, the ecological risk and health risk for crab cultivation in paddy fields should be of particular concern.
基金supported by the National Natural Science Foundation of China (No. 21377032)the Chinese Polar Environment Comprehensive Investigation and Assessment Program (Nos. 2014-02-01, 2014-03-04, 2014-04-01, 2014-04-03)+1 种基金the Marine Public Welfare Scientific Research Projects (No. 201105013)the Foundation of Polar Science Key Laboratory, SOA, China (No. KP201208)
文摘In recent years, Dechloranes have been widely detected in the environment around the world.However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic,remain lacking. Therefore, the concentrations of 5 Dechloranes in surface seawater, sediment,soil, moss, and dung collected from Ny-lesund in the Arctic were measured with the concentrations 93 pg/L, 342, 325, 1.4, and 258 pg/g, respectively, which were much lower than those in Asian and European regions. The mean ratios of anti-Dechlorane Plus(DP) to total DP(fanti) in seawater, sediment, soil, moss, dung, and atmospheric samples were 0.36, 0.21, 0.18,0.27, 0.66, and 0.43, respectively. Results suggested that the main source of DP in seawater,sediment, soil, and moss was long-range atmospheric transport. However, the ratio identified in dung was different, for which the migration behavior of the organism is probably the main source of DP.
基金supported by the National Key Research and Development Program of China(No.2020YFA0607500)the National Natural Science Foundation of China(Nos.41775127 and 42075112)+3 种基金Key Laboratory of Global Change and Marine Atmospheric Chemistry,Ministry of Natural Resources(No.GCMAC2001)the Basic Research Fund of Chinese Academy of Meteorological Sciences(No.2020Z002)Key Laboratory of Atmospheric Chemistry,China Meteorological Administration(No.2019B07)Key Laboratory on Marine Hazards Forcasting,Ministry of Natural Resources(No.LOMF1803)
文摘Sediment is recognized as the largest reservoir and source of methane(CH_(4))in the ocean,especially in the shallow coastal areas.To date,few data of CH_(4)concentration in sediment have been reported in the China shelf seas.In this study,we measured CH_(4)concentration in sediment and overlying seawater columns,and conducted an incubation experiment in the Bohai Sea in May 2017.CH_(4)concentration was found to be ranged from 3.075 to 1.795μmol/L in sediment,which was 2 to 3 orders of magnitude higher than that in overlying seawater columns.The surface sediment was an important source of CH_(4),while bottom seawater acted as its sink.Furthermore,the net emission rate via sediment water interface(SWI)was calculated as 2.45μmol/(m^(2)·day)based on the incubation experiment at station73,and the earthquake may enhance CH_(4)release from sediment to seawater column in the eastern Bohai Sea.
基金This study was supported by Excellent Young Scientist Program of Zhejang Provincial Natural Science Foundation of China(LR19D050001)National Key ResearchandDevelopment Programof China(2016YFC1400900)+1 种基金Fundamental Research Funds for the Central Universities(international team)Scientific Research Foundation for Talent Introduction(20201203Z0175,20201203Z0177)of Zhejiang University Ningbo Campus.
文摘Lidar techniques present a distinctive ability to resolve vertical structure of optical properties within the upper water column at both day-and night-time.However,accuracy challenges remain for existing lidar instruments due to the ill-posed nature of elastic backscatter lidar retrievals and multiple scattering.Here we demonstrate the high performance of,to the best of our knowledge,the first shipborne oceanic high-spectral-resolution lidar(HSRL)and illustrate a multiple scattering correction algorithm to rigorously address the above challenges in estimating the depth-resolved diffuse attenuation coefficient Kd and the particulate backscattering coefficient bbp at 532 nm.HSRL data were collected during day-and night-time within the coastal areas of East China Sea and South China Sea,which are connected by the Taiwan Strait.Results include vertical profiles from open ocean waters to moderate turbid waters and first lidar continuous observation of diel vertical distribution of thin layers at a fixed station.The root-mean-square relative differences between the HSRL and coincident in situ measurements are 5.6%and 9.1%for Kd and bbp,respectively,corresponding to an improvement of 2.7-13.5 and 4.9-44.1 times,respectively,with respect to elastic backscatter lidar methods.Shipborne oceanic HSRLs with high performance are expected to be of paramount importance for the construction of 3D map of ocean ecosystem.
