2010 Vol. 29, No. 2
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2010, (2): 1-4.
doi: 10.1007/s13131-010-0016-o
Abstract:
For selected locations in the Atlantic and Pacific Ocean, we compared surface ocean chlorophyll time series extracted from SeaWiFS imagery from 1997-2004 with the results of an ocean coupled circulation and biogeochemical model covering the period 1958-2004. During the 1997-2004 time period, linear trends in model and satellite time series were significantly correlated at most of the 44 sites we studied. Eleven sites were selected for further study, and we used the longer time series of the model to assess whether trends observed during the SeaWiFS period at these 11 sites were unusual in relation to those observed over the longer historical period covered by the model. The results show that the trends observed during the SeaWiFS period were not unusual and fell well within the range in magnitude of linear trends observed in other 8-year periods of model output. This result implies that the SeaWiFS satellite ocean color time series is not yet sufficiently long, on its own, to directly observe any long term changes in phytoplankton chlorophyll that may be occurring in the surface waters of the open ocean as a result of increased ocean stratification linked to global climate changed.
For selected locations in the Atlantic and Pacific Ocean, we compared surface ocean chlorophyll time series extracted from SeaWiFS imagery from 1997-2004 with the results of an ocean coupled circulation and biogeochemical model covering the period 1958-2004. During the 1997-2004 time period, linear trends in model and satellite time series were significantly correlated at most of the 44 sites we studied. Eleven sites were selected for further study, and we used the longer time series of the model to assess whether trends observed during the SeaWiFS period at these 11 sites were unusual in relation to those observed over the longer historical period covered by the model. The results show that the trends observed during the SeaWiFS period were not unusual and fell well within the range in magnitude of linear trends observed in other 8-year periods of model output. This result implies that the SeaWiFS satellite ocean color time series is not yet sufficiently long, on its own, to directly observe any long term changes in phytoplankton chlorophyll that may be occurring in the surface waters of the open ocean as a result of increased ocean stratification linked to global climate changed.
2010, (2): 5-13.
doi: 10.1007/s13131-010-0017-Z
Abstract:
In the present paper, by introducing the effective wave elevation, we transform the extended elliptic mild-slope equation with bottom friction, wave breaking and steep or rapidly varying bottom topography to the simplest time-dependent hyperbolic equation. Based on this equation and the empirical nonlinear amplitude dispersion relation proposed by Li et al. (2003), the numerical scheme is established. Error analysis by Taylor expansion method shows that the numerical stability of the present model succeeds the merits in Song et al. (2007)'s model because of the introduced dissipation terms. For the purpose of verifying its performance on wave nonlinearity, rapidly varying topography and wave breaking, the present model is applied to study:(1) wave refraction and diffraction over a submerged elliptic shoal on a slope (Berkhoff et al., 1982); (2) Bragg reflection of monochromatic waves from the sinusoidal ripples (Davies and Heathershaw, 1985); (3) wave transformation near a shore attached breakwater (Watanabe and Maruyama, 1986). Comparisons of the numerical solutions with the experimental or theoretical ones or with those of other models (REF/DIF model and FUNWAVE model) show good results, which indicate that the present model is capable of giving favorably predictions of wave refraction, diffraction, reflection, shoaling, bottom friction, breaking energy dissipation and weak nonlinearity in the near shore zone.
In the present paper, by introducing the effective wave elevation, we transform the extended elliptic mild-slope equation with bottom friction, wave breaking and steep or rapidly varying bottom topography to the simplest time-dependent hyperbolic equation. Based on this equation and the empirical nonlinear amplitude dispersion relation proposed by Li et al. (2003), the numerical scheme is established. Error analysis by Taylor expansion method shows that the numerical stability of the present model succeeds the merits in Song et al. (2007)'s model because of the introduced dissipation terms. For the purpose of verifying its performance on wave nonlinearity, rapidly varying topography and wave breaking, the present model is applied to study:(1) wave refraction and diffraction over a submerged elliptic shoal on a slope (Berkhoff et al., 1982); (2) Bragg reflection of monochromatic waves from the sinusoidal ripples (Davies and Heathershaw, 1985); (3) wave transformation near a shore attached breakwater (Watanabe and Maruyama, 1986). Comparisons of the numerical solutions with the experimental or theoretical ones or with those of other models (REF/DIF model and FUNWAVE model) show good results, which indicate that the present model is capable of giving favorably predictions of wave refraction, diffraction, reflection, shoaling, bottom friction, breaking energy dissipation and weak nonlinearity in the near shore zone.
2010, (2): 14-32.
doi: 10.1007/s13131-010-0018-y
Abstract:
An important goal in ocean colour remote sensing is to accurately detect different phytoplankton groups with the potential uses including the validation of multi-phytoplankton carbon cycle models; synoptically monitoring the health of our oceans, and improving our understanding of the bio-geochemical interactions between phytoplankton and their environment. In this paper a new algorithm is developed for detecting three dominant phytoplankton size classes based on distinct differences in their optical signatures. The technique is validated against an independent coupled satellite reflectance and in situ pigment dataset and run on the 10-year NASA Sea viewing Wide Field of view Sensor (SeaWiFS) data series. Results indicate that on average 3.6% of the global oceanic surface layer is dominated by microplankton, 18.0% by nanoplankton and 78.4% by picoplankton. Results, however, are seen to vary depending on season and ocean basin.
An important goal in ocean colour remote sensing is to accurately detect different phytoplankton groups with the potential uses including the validation of multi-phytoplankton carbon cycle models; synoptically monitoring the health of our oceans, and improving our understanding of the bio-geochemical interactions between phytoplankton and their environment. In this paper a new algorithm is developed for detecting three dominant phytoplankton size classes based on distinct differences in their optical signatures. The technique is validated against an independent coupled satellite reflectance and in situ pigment dataset and run on the 10-year NASA Sea viewing Wide Field of view Sensor (SeaWiFS) data series. Results indicate that on average 3.6% of the global oceanic surface layer is dominated by microplankton, 18.0% by nanoplankton and 78.4% by picoplankton. Results, however, are seen to vary depending on season and ocean basin.
2010, (2): 33-39.
doi: 10.1007/s13131-010-0019-x
Abstract:
China Marine Surveillance Force was equipped with modern aerial equipments for marine lawexecute with the advantage of functioning agilely at a large scale of surveillance coverage, providing powerful all-round safeguard, which is of benefit to the harmonious and sustainable development of coastal economy. Onboard the planes, three kinds of remote sensing sensors have been installed, including a marine airborne multi-spectrum scanner (MAMS), an optical-electronic platform, and an airborne hyper-spectral system AISA+. The specifications of remote sensing platforms were introduced briefly first, then examples of water quality monitoring by airborne remote sensing were presented, including the monitoring in coastal suspended material, oil-spill and abnormal warm water, etc.
China Marine Surveillance Force was equipped with modern aerial equipments for marine lawexecute with the advantage of functioning agilely at a large scale of surveillance coverage, providing powerful all-round safeguard, which is of benefit to the harmonious and sustainable development of coastal economy. Onboard the planes, three kinds of remote sensing sensors have been installed, including a marine airborne multi-spectrum scanner (MAMS), an optical-electronic platform, and an airborne hyper-spectral system AISA+. The specifications of remote sensing platforms were introduced briefly first, then examples of water quality monitoring by airborne remote sensing were presented, including the monitoring in coastal suspended material, oil-spill and abnormal warm water, etc.
2010, (2): 40-52.
doi: 10.1007/s13131-010-0020-4
Abstract:
The evolvement history of modern Huanghe River Delta tidal flat, coastline and underwater terrain were studied based on the analysis of remote sensing images and water depth data. Based on the analysis of seafloor terrain evolution on different historical stages, a formula simulating the erosion and deposition evolvement model of subaqueous Huanghe River Delta slope was proposed, and the evolvement trend of the subaqueous delta terrain was predicted. The result shows that the equilibrium transition zone is near the water depth of 12 m with seabed erosion in shallower water and accumulation in deeper water during the first 150 a after the river channel was deserted. In the meantime, the underwater slope became gentler and the coastal erosion rate became slow gradually. Then, the subaqueous delta slope changed to up concave from upper convex, and the shape of subaqueous delta disappeared. The coast type changed to silt-mud coast about 100-150 a after the river course was deserted. The erosion depth in the foot of the seawall is calculated based on the formula.
The evolvement history of modern Huanghe River Delta tidal flat, coastline and underwater terrain were studied based on the analysis of remote sensing images and water depth data. Based on the analysis of seafloor terrain evolution on different historical stages, a formula simulating the erosion and deposition evolvement model of subaqueous Huanghe River Delta slope was proposed, and the evolvement trend of the subaqueous delta terrain was predicted. The result shows that the equilibrium transition zone is near the water depth of 12 m with seabed erosion in shallower water and accumulation in deeper water during the first 150 a after the river channel was deserted. In the meantime, the underwater slope became gentler and the coastal erosion rate became slow gradually. Then, the subaqueous delta slope changed to up concave from upper convex, and the shape of subaqueous delta disappeared. The coast type changed to silt-mud coast about 100-150 a after the river course was deserted. The erosion depth in the foot of the seawall is calculated based on the formula.
2010, (2): 53-57.
doi: 10.1007/s13131-010-0021-3
Abstract:
Along with the reduction of sediment yield of the Huanghe (Yellow) River, the erosion of the Huanghe River Delta aggravates, which has becomes an important factor that threatens the coastal protection structures. Starting from the study of the erosion resistibility of the sediment, this paper explores the internal mechanism of erosion phenomenon. This paper takes Diaokou as the study area and takes soils as samples which are mixed with clay into reconstructed samples whose ratio of clay content are 5%, 10%, 15%, 20% respectively, then dynamic tri-axial apparatus is applied to simulate wave loads of different intensity; then the resistibility of soil to erosion is determined via concentrated flow test and the structural property is determined via the disintegration test. Finally, the resistibility to erosion and the structural property of the non-compressed soil samples are compared with the compressed data. The results indicates that liquefaction failure exerts significant influence on the resistibility to erosion and the structural property of the silty soil in the Huanghe River Delta. Therefore, in the future erosion studies, the liquefaction phenomenon shall be fully considered.
Along with the reduction of sediment yield of the Huanghe (Yellow) River, the erosion of the Huanghe River Delta aggravates, which has becomes an important factor that threatens the coastal protection structures. Starting from the study of the erosion resistibility of the sediment, this paper explores the internal mechanism of erosion phenomenon. This paper takes Diaokou as the study area and takes soils as samples which are mixed with clay into reconstructed samples whose ratio of clay content are 5%, 10%, 15%, 20% respectively, then dynamic tri-axial apparatus is applied to simulate wave loads of different intensity; then the resistibility of soil to erosion is determined via concentrated flow test and the structural property is determined via the disintegration test. Finally, the resistibility to erosion and the structural property of the non-compressed soil samples are compared with the compressed data. The results indicates that liquefaction failure exerts significant influence on the resistibility to erosion and the structural property of the silty soil in the Huanghe River Delta. Therefore, in the future erosion studies, the liquefaction phenomenon shall be fully considered.
2010, (2): 58-61.
doi: 10.1007/s13131-010-0022-2
Abstract:
Two new species of genus Ectopleura, i.e., Ectopleura elongata sp. nov. and E. triangularis sp. nov. are described in the present paper based on type specimens from the Taiwan Strait. The types are deposited in the Third Institute of Oceanography, State Oceanic Administration, Xiamen, China.
Two new species of genus Ectopleura, i.e., Ectopleura elongata sp. nov. and E. triangularis sp. nov. are described in the present paper based on type specimens from the Taiwan Strait. The types are deposited in the Third Institute of Oceanography, State Oceanic Administration, Xiamen, China.
2010, (2): 62-69.
doi: 10.1007/s13131-010-0023-1
Abstract:
A study was undertaken to investigate the heterotrophic bacterial flora associated with the sea anemones. Samples of the sea anemones Anthopleura midori were collected from the coast of Weihai and bacteria were isolated from these samples. Additionally, high numbers of viable bacteria were obtained from the celom wall and surface of anemone, the community of cultivable bacteria was very diverse. As a result of this isolation, 60 strains were obtained, 56 of them were selected for identification and characterization by 16S rRNA gene sequence analysis and limited phenotypic testing. Among these isolates, 16 strains were phylogenetically related to members of the genus Pseudoalteromonas and neighboring taxa. Other isolates included members of the genera Colwellia, Vibrio, Acinetobacter, Pseudomonas, Endozoicomonas, Roseovarius, Paracoccus, Loktanella, Leisingera, Sulfitobacter, Bacillus, Staphylococcus, Plantibacter, Microbacterium, Micrococcus, Joostella, Psychroserpens, Cellulophaga, Krokinobacter, Polaribacter and Psychrobacter. Seven potential novel species were found. Among 60 strains, 17 of them can produce proteolytic exoenzyme, 20 can produce lipolytic exoenzyme. Strain NQ8 has strong antagonistic effects on some Vibrio strains. This study demonstrates that the culturable fraction of bacteria from the sea anemones Anthopleura midori is diverse and appears to possess much potential as a source for the discovery of novel bioactive materials.
A study was undertaken to investigate the heterotrophic bacterial flora associated with the sea anemones. Samples of the sea anemones Anthopleura midori were collected from the coast of Weihai and bacteria were isolated from these samples. Additionally, high numbers of viable bacteria were obtained from the celom wall and surface of anemone, the community of cultivable bacteria was very diverse. As a result of this isolation, 60 strains were obtained, 56 of them were selected for identification and characterization by 16S rRNA gene sequence analysis and limited phenotypic testing. Among these isolates, 16 strains were phylogenetically related to members of the genus Pseudoalteromonas and neighboring taxa. Other isolates included members of the genera Colwellia, Vibrio, Acinetobacter, Pseudomonas, Endozoicomonas, Roseovarius, Paracoccus, Loktanella, Leisingera, Sulfitobacter, Bacillus, Staphylococcus, Plantibacter, Microbacterium, Micrococcus, Joostella, Psychroserpens, Cellulophaga, Krokinobacter, Polaribacter and Psychrobacter. Seven potential novel species were found. Among 60 strains, 17 of them can produce proteolytic exoenzyme, 20 can produce lipolytic exoenzyme. Strain NQ8 has strong antagonistic effects on some Vibrio strains. This study demonstrates that the culturable fraction of bacteria from the sea anemones Anthopleura midori is diverse and appears to possess much potential as a source for the discovery of novel bioactive materials.
2010, (2): 70-80.
doi: 10.1007/s13131-010-0024-0
Abstract:
Taxonomic diversity of fish assemblages in the Changjiang Estuary (Yangtze River Estuary) and its adjacent waters was analyzed based on bottom trawl surveys carried out by R/V Beidou in June, August and October 2006. Four groups of fishes were identified for each survey by the twoway indicator species analysis (TWIA). Taxonomic distinctness, species richness and phylogenetic diversity were used to detect changes in taxonomic structure of fish assemblages. Most dominant fish species mainly belonged to Perciformes, Pleuronectiformes, Clupeiformes, Scorpaeniformes and Tetraodontiformes. Species richness in offshore waters of the survey area was higher than that in the other area. The average taxonomic distinctness value (AvTD, △+) of each fish assemblage was close to the average taxonomic distinctness of master list in the Changjiang Estuary (79.9), and had a positive correlation with species richness and Shannon diversity index (H'). A negative correlation was found between variations in taxonomic distinctness (VarTD, Λ+) and traditional diversity indices, which were caused by fish species component that led to longer average path lengths among species. Taxonomic diversity index (△) had the similar results with species richness, H', Simpson diversity index (D) and Pielou's evenness index (J'). VarTD also kept stable, which further certificated that fish assemblages and ecological environment were in equilibrium. Taxonomic distinctness index (△*) was relatively stable in most of fish assemblages, and had higher values in some fish assemblages for a few absolutely dominant species. The present study showed that fish community formed new equilibrium stability in 2006 in the Changjiang Estuary when compared with those in the corresponding months of annual survey from 1985 to 1986. And AvTD in each sampling station was lower than AvTD of master list in the Changjiang Estuary, so some ecological niches were absent in each sampling stations from taxonomic or phylogenetic relationships, these would be helpful to stock natural resource and maintain ecological equilibruim of fish assemblages.
Taxonomic diversity of fish assemblages in the Changjiang Estuary (Yangtze River Estuary) and its adjacent waters was analyzed based on bottom trawl surveys carried out by R/V Beidou in June, August and October 2006. Four groups of fishes were identified for each survey by the twoway indicator species analysis (TWIA). Taxonomic distinctness, species richness and phylogenetic diversity were used to detect changes in taxonomic structure of fish assemblages. Most dominant fish species mainly belonged to Perciformes, Pleuronectiformes, Clupeiformes, Scorpaeniformes and Tetraodontiformes. Species richness in offshore waters of the survey area was higher than that in the other area. The average taxonomic distinctness value (AvTD, △+) of each fish assemblage was close to the average taxonomic distinctness of master list in the Changjiang Estuary (79.9), and had a positive correlation with species richness and Shannon diversity index (H'). A negative correlation was found between variations in taxonomic distinctness (VarTD, Λ+) and traditional diversity indices, which were caused by fish species component that led to longer average path lengths among species. Taxonomic diversity index (△) had the similar results with species richness, H', Simpson diversity index (D) and Pielou's evenness index (J'). VarTD also kept stable, which further certificated that fish assemblages and ecological environment were in equilibrium. Taxonomic distinctness index (△*) was relatively stable in most of fish assemblages, and had higher values in some fish assemblages for a few absolutely dominant species. The present study showed that fish community formed new equilibrium stability in 2006 in the Changjiang Estuary when compared with those in the corresponding months of annual survey from 1985 to 1986. And AvTD in each sampling station was lower than AvTD of master list in the Changjiang Estuary, so some ecological niches were absent in each sampling stations from taxonomic or phylogenetic relationships, these would be helpful to stock natural resource and maintain ecological equilibruim of fish assemblages.
2010, (2): 81-87.
doi: 10.1007/s13131-010-0025-z
Abstract:
A new cell line, CSEC, has been successfully established from embryos at gastrula stage of a cultured marine fish, half smooth tongue sole (Cynoglossus semilaevis). CSEC cells grow actively and stably more than 50 passages for over 200 d in DMEM medium supplemented with 15% FBS (fetal bovine serum), 2.5 ng/cm3 bFGF (basic fibroblast growth factor), 1 ng/cm3 LIF (leukemia inhibitory factor) and 50 mmol/dm3 2-ME (2-mecaptoethanol). The cells grew well in the temperature range of 24-30℃ and the optimal growth temperature was 24℃. FBS and bFGF concentrations are the two key components for CSEC cells proliferation. Chromosome analysis reveals that CSEC cells have a normal diploid karyotype with 2n=42t. The significant fluorescent signals were observed in CSEC after transfection with the GFP reporter gene, suggesting that the CSEC cell line can be used as a useful tool for transgenic and genetic manipulation studies. CSEC cells showed the cytopathic effect (CPE) after infection with lymphosystis disease virus (LCDV) in 2 d. Moreover, the LCDV particles can be observed in the cytoplasm of virus-infected cells by electron microscopy. It suggests that CSEC could be potentially used for the study of aquatic virus.
A new cell line, CSEC, has been successfully established from embryos at gastrula stage of a cultured marine fish, half smooth tongue sole (Cynoglossus semilaevis). CSEC cells grow actively and stably more than 50 passages for over 200 d in DMEM medium supplemented with 15% FBS (fetal bovine serum), 2.5 ng/cm3 bFGF (basic fibroblast growth factor), 1 ng/cm3 LIF (leukemia inhibitory factor) and 50 mmol/dm3 2-ME (2-mecaptoethanol). The cells grew well in the temperature range of 24-30℃ and the optimal growth temperature was 24℃. FBS and bFGF concentrations are the two key components for CSEC cells proliferation. Chromosome analysis reveals that CSEC cells have a normal diploid karyotype with 2n=42t. The significant fluorescent signals were observed in CSEC after transfection with the GFP reporter gene, suggesting that the CSEC cell line can be used as a useful tool for transgenic and genetic manipulation studies. CSEC cells showed the cytopathic effect (CPE) after infection with lymphosystis disease virus (LCDV) in 2 d. Moreover, the LCDV particles can be observed in the cytoplasm of virus-infected cells by electron microscopy. It suggests that CSEC could be potentially used for the study of aquatic virus.
2010, (2): 88-92.
doi: 10.1007/s13131-010-0026-y
Abstract:
The nucleotide sequence of the mitochondrial genome of the solecurtidae Bivalvia mollusca Sinonovacula constricta (GenBank accession number EU880278) has been determined and is reported here. We determined the complete mitochondrial genome sequence using long-PCR and Shot Gun Sequencing. Contained within the 17 225 base pairs (bp) are the two ribosomal RNA genes and 12 protein coding genes typical of metazoan mitochondrial genomes. The S. constricta mitochondrial DNA (mtDNA) did not contain a gene for atp8, similar to the mtDNA of Crassostrea virginica, Crassostrea giga and Mytilus edulis. The S. constricta mtDNA is 67.0% A+T (A 25.9%, C 10.5%, G 22.5%, and T 41.1%). This value is higher than that for many invertebrate mitochondrial genomes. Only 19 putative tRNA genes are present in S. constricta and 27 noncoding regions, of which two are large in size. The trnE and trnW genes as well as a second trnS were absent in S. constricta. The gene arrangement of S. constricta is different from the other Bivalvia genomes.
The nucleotide sequence of the mitochondrial genome of the solecurtidae Bivalvia mollusca Sinonovacula constricta (GenBank accession number EU880278) has been determined and is reported here. We determined the complete mitochondrial genome sequence using long-PCR and Shot Gun Sequencing. Contained within the 17 225 base pairs (bp) are the two ribosomal RNA genes and 12 protein coding genes typical of metazoan mitochondrial genomes. The S. constricta mitochondrial DNA (mtDNA) did not contain a gene for atp8, similar to the mtDNA of Crassostrea virginica, Crassostrea giga and Mytilus edulis. The S. constricta mtDNA is 67.0% A+T (A 25.9%, C 10.5%, G 22.5%, and T 41.1%). This value is higher than that for many invertebrate mitochondrial genomes. Only 19 putative tRNA genes are present in S. constricta and 27 noncoding regions, of which two are large in size. The trnE and trnW genes as well as a second trnS were absent in S. constricta. The gene arrangement of S. constricta is different from the other Bivalvia genomes.
2010, (2): 93-97.
doi: 10.1007/s13131-010-0027-x
Abstract:
Vibrio vulnificus is an opportunistic pathogen widely distributed in estuarine and coastal seawaters. In this study, a culture-free method was developed to rapid detection of V. vulnificus in all seasons, based on loop-mediated isothermal amplification (LAMP) targeting virulent-correlated gene (vcg). The new assay method allows differentiation between the virulent and non-virulent strain of V. vulnificus accurately. This method also allows effective detection of the pathogeny in winter when the bacterium lives in the viable but non-culturable (VBNC) state. A total of 30 costal seawater samples collected in all seasons were used for the evaluation of this method. The results show that the method is sensitive, accurate and convenient.
Vibrio vulnificus is an opportunistic pathogen widely distributed in estuarine and coastal seawaters. In this study, a culture-free method was developed to rapid detection of V. vulnificus in all seasons, based on loop-mediated isothermal amplification (LAMP) targeting virulent-correlated gene (vcg). The new assay method allows differentiation between the virulent and non-virulent strain of V. vulnificus accurately. This method also allows effective detection of the pathogeny in winter when the bacterium lives in the viable but non-culturable (VBNC) state. A total of 30 costal seawater samples collected in all seasons were used for the evaluation of this method. The results show that the method is sensitive, accurate and convenient.
2010, (2): 98-106.
doi: 10.1007/s13131-010-0028-9
Abstract:
Sediment transport in the Hangzhou Bay is extremely complicated due to its bathymetry and hydrodynamic conditions. The ECOMSED model is employed to simulate three-dimensional (3-D) cohesive sediment transport in Hangzhou Bay. Dynamical factors such as Coriolis force, tides, salinity, river discharges, and waves are considered in the model. The wave parameters, including the significant wave height, period, and direction, are calculated with the SWAN model. The Grant-Madsen model is introduced for the bed shear stress due to the combined effect of waves and currents. The formulation of bed shear stress used to calculate the sink/source terms is modified based on previous research that sufficiently validated the formulation with measurement data. The integrated model of the above-mentioned models is applied to simulate sediment transport in Hangzhou Bay. The results of the simulation agree well with field observations concerning the distribution of suspended sediment, indicating that the sediments are remarkably suspended in Hangzhou Bay under the action of waves and currents.
Sediment transport in the Hangzhou Bay is extremely complicated due to its bathymetry and hydrodynamic conditions. The ECOMSED model is employed to simulate three-dimensional (3-D) cohesive sediment transport in Hangzhou Bay. Dynamical factors such as Coriolis force, tides, salinity, river discharges, and waves are considered in the model. The wave parameters, including the significant wave height, period, and direction, are calculated with the SWAN model. The Grant-Madsen model is introduced for the bed shear stress due to the combined effect of waves and currents. The formulation of bed shear stress used to calculate the sink/source terms is modified based on previous research that sufficiently validated the formulation with measurement data. The integrated model of the above-mentioned models is applied to simulate sediment transport in Hangzhou Bay. The results of the simulation agree well with field observations concerning the distribution of suspended sediment, indicating that the sediments are remarkably suspended in Hangzhou Bay under the action of waves and currents.
2010, (2): 107-119.
doi: 10.1007/s13131-010-0029-8
Abstract:
In June 2003 and 2006 concentrations of nutrient were determined in the Changjiang Estuary. The data indicated that phosphate and nitrate did not behave conservatively in the estuary, but silicate behaved conservatively. An important mobilization of phosphate and nitrate was observed from the river up to halfway in the estuary. Both input flux (from river to estuary) and output flux (from estuary to coastal zone) of phosphate, silicate and nitrate were calculated from statistical interpretations of the salinity profiles. There was a large discrepancy between input and output fluxes of phosphate and nitrate. The river fluxes of silicate, phosphate and nitrate (fr) are augmented 5.3%, 28.9% and 36.6% in June 2003 and 1.0%, 62.5%, 31.7% in June 2006 by internal inputs (fi). The phosphate and nitrate fluxes are enhanced through the estuarine process, while silicate flux is unaltered. The authors present some long-term data for nutrient concentrations and the ratios of silicon to nitrogen to phosphorus in the Changjiang Estuary. Silicate level falled in the last two decades, while concentration of nitrate increased. Phosphate concentration had no significant change.
In June 2003 and 2006 concentrations of nutrient were determined in the Changjiang Estuary. The data indicated that phosphate and nitrate did not behave conservatively in the estuary, but silicate behaved conservatively. An important mobilization of phosphate and nitrate was observed from the river up to halfway in the estuary. Both input flux (from river to estuary) and output flux (from estuary to coastal zone) of phosphate, silicate and nitrate were calculated from statistical interpretations of the salinity profiles. There was a large discrepancy between input and output fluxes of phosphate and nitrate. The river fluxes of silicate, phosphate and nitrate (fr) are augmented 5.3%, 28.9% and 36.6% in June 2003 and 1.0%, 62.5%, 31.7% in June 2006 by internal inputs (fi). The phosphate and nitrate fluxes are enhanced through the estuarine process, while silicate flux is unaltered. The authors present some long-term data for nutrient concentrations and the ratios of silicon to nitrogen to phosphorus in the Changjiang Estuary. Silicate level falled in the last two decades, while concentration of nitrate increased. Phosphate concentration had no significant change.
2010, (2): 120-126.
doi: 10.1007/s13131-010-0030-2
Abstract:
The main objective of this study was to investigate toxic effects of the dinoflagellate Alexandrium species, on cladocera Moina mongolica in the laboratory. Ten strains of Alexandrium species, including Alexandrium tamarense (AT-6, ATHK, ATCI02, ATCI03 and AT5-1), A. catenella (ACDH), A. affine (AC-1 and AS-1), A. lusitanicum and A. minutum were tested. The results showed that A. tamarense (ATHK, ATCI02 and AT5-1) and A. affine (AC-1 and AS-1), but not A. tamarense (AT-6 and ATCI02), A. catenella (ACDH), A. lusitanicum and A. minutum had significantly negative effects on the survival of M. mongolica; when exposed to these ten strains of Alexandrium species in densities of 3 000 cells/cm3 for 7 d, respecyively. M. mongolica could feed on A. tamarense (AT-6, ATHK, ATCI02, ATCI03 and AT5-1), A. catenella, A. lusitanicum and A. minutum, but exhibited little or no grazing on A. affine (AC-1 and AS-1), based on the changes in gut pigment after exposure to alga for 1 and 12 h. A. affine AC-1, which had the strongest toxicity on the survival of M. mongolica, was chosen to further study the negative effects on M. mongolica. The results showed that the effect of A. affine AC-1 on the survival of M. mongolica was density-dependent, and its lethal effects on one-day, two-day and three-day old M. mongolica were exacerbated with increasing age; The whole algal culture, re-suspended algal cells, cell fragments and cell contents all had adverse impacts on the survival of M. mongolica. Moreover, both juvenile numbers and life-span time of M. mongolica were decreased significantly when they were cultured in A. affine AC-1 of 10 and 50 cells/cm3, combined with 3×106 cells/cm3 of Chlorella spp., respectively. As a non-PSP producer, A. affine may produce other toxins, responsible for the strong negative effects on M. mongolica.
The main objective of this study was to investigate toxic effects of the dinoflagellate Alexandrium species, on cladocera Moina mongolica in the laboratory. Ten strains of Alexandrium species, including Alexandrium tamarense (AT-6, ATHK, ATCI02, ATCI03 and AT5-1), A. catenella (ACDH), A. affine (AC-1 and AS-1), A. lusitanicum and A. minutum were tested. The results showed that A. tamarense (ATHK, ATCI02 and AT5-1) and A. affine (AC-1 and AS-1), but not A. tamarense (AT-6 and ATCI02), A. catenella (ACDH), A. lusitanicum and A. minutum had significantly negative effects on the survival of M. mongolica; when exposed to these ten strains of Alexandrium species in densities of 3 000 cells/cm3 for 7 d, respecyively. M. mongolica could feed on A. tamarense (AT-6, ATHK, ATCI02, ATCI03 and AT5-1), A. catenella, A. lusitanicum and A. minutum, but exhibited little or no grazing on A. affine (AC-1 and AS-1), based on the changes in gut pigment after exposure to alga for 1 and 12 h. A. affine AC-1, which had the strongest toxicity on the survival of M. mongolica, was chosen to further study the negative effects on M. mongolica. The results showed that the effect of A. affine AC-1 on the survival of M. mongolica was density-dependent, and its lethal effects on one-day, two-day and three-day old M. mongolica were exacerbated with increasing age; The whole algal culture, re-suspended algal cells, cell fragments and cell contents all had adverse impacts on the survival of M. mongolica. Moreover, both juvenile numbers and life-span time of M. mongolica were decreased significantly when they were cultured in A. affine AC-1 of 10 and 50 cells/cm3, combined with 3×106 cells/cm3 of Chlorella spp., respectively. As a non-PSP producer, A. affine may produce other toxins, responsible for the strong negative effects on M. mongolica.
