2006 Vol. 25, No. 6

Display Method:
Features of physical oceanography in the oceans near the Prydz Bay during the 1998/1999 austral summer
PU Shuzhen, HU Xiaomin, DONG Zhaoqian, XIANG Baoqiang, YU Weidong
2006, (6): 1-14.
Thermohaline features, spatial extensions, and depths of the antarctic circumpolar deep water, the antarctic bottom water, and the upper layer water near the Prydz Bay (including the Prydz Bay summer surface water, the antarctic winter water, and the Prydz Bay shelf water) are analyzed and studied by use of the full depth CTD data obtained in the Southern Ocean near the Prydz Bay during the 1998/1999 austral summer.The northward extension of the shelf water, the thickness of the temperature inversion layer, the minima in the vertical temperature profile and the vertical temperature gradient are interpreted.On the basis of analysis of gravitational potential field, the geostrophic current and the geostrophic volume transport are calculated to determine the location of the strongest current in the zonal circulation near the Prydz Bay and to find the spatial variability of the volume transport in the 64°~66.5°S zone.In addition, the central location, the frontal strength, the vertical depth and thickness of the continental water boundary (CWB) are estimated from the CTD data to expound the spatial variability of CWB in the study area (64°~66.5°S, 70°~75°E).
Adjustment time of the first baroclinic Rossby wave in the global oceans
FAN Haimei, LI Bingrui, XU Ren, ZHANG Zhenglong, LI Yihong
2006, (6): 15-21.
According to the freely linear Rossby wave theory, global 1°×1° climatology of Rossby deformation radius and phase speed are studied under the flat bottom fluid approximation.Geographical variations in the contours of the phase speed are very similar to those of the Rossby radius of formation, which are mainly affected by stratification, rotation, water depth, topography, etc.The basin-crossing time of the first baroclinic Rossby wave is obtained and analyzed in the global ocean basins.The results are useful to learn the importance of Rossby wave and the adiabatic adjustment of large-scale ocean circulation.
Relationship between Indian Ocean dipole and ENSO and their connection with the onset of South China Sea summer monsoon
LIANG Zhaoning, WEN Zhiping, LIANG Jieyi, WU Liji, WU Naigeng
2006, (6): 22-32.
Using Reynolds and Smith 1950~1998 re-constructed monthly-mean SST to discuss the relationship between the ENSO and Indian Ocean dipole (IOD) and their possible connection with the onset of South China Sea summer monsoon (SCSSM), the results are obtained as follows:Most of IOD events have a closely positive relation to simultaneous ENSO events in summer and autumn.IOD events in autumn (mature phase) are also closely related to ENSO events in winter (mature phase).When these two kinds of events happen in phase, i.e., positive (negative) IOD events are coupled with El Niño (La Nina) events, they are always followed by late (or early) onsets of SCSSM.On the contrary, when these two kinds of events happen out of phase, I.e.Positive (negative) IOD events are coupled with La Nina (El Niño) events, they are followed by normal onsets of SCSSM.In addition, single IOD events or single ENSO events cannot correspond well to the abnormal onset of SCSSM.
Quantizing and analyzing the feature information of coastal zone based on high-resolution remote sensing image
YANG Xiaomei, LAN Rongqin, LUO Jiancheng
2006, (6): 33-42.
On the basis of realization of beach information and its differentiating of high-resolution remote sensing image on coastal zone, extracting objects are carried through RS multi-scale diagnostic analysis, and fast information extraction methods and key technologies are put forward.Meanwhile image segmentation methods are set forth for objects of coastal zone.And through the application of Otsu2D to the segmentation of water area and dock and the applying of Gabor filter to the separation and extraction of construction, some typical applications of high-resolution RS image are presented in the field of coastal zone surface objects' recognition.Quantizing high-resolution RS information on the coastal zone proved to be of great scientific and practical significance for coastal development and management.
Heat and mass flux estimation of modern seafloor hydrothermal activity
ZHAI Shikui, WANG Xingtao, YU Zenghui
2006, (6): 43-51.
Research on heat and mass flux yielded by modern seafloor hydrothermal activity is very important, because it is involved not only in the base of ocean environment research, but also in the historical evolution of seawater properties.Currently, estimating heat flux is based on the observation data of hydrothermal smokers, low-temperature diffusive flow and mid-ocean ridge mainly.But there are some faults, for example, there is lack of a concurrent conductive item in estimating the heat flux by smokers and the error between the half-space cooling model and the observation data is too large.So, three kinds of methods are applied to re-estimating the heat flux of hydrothermal activity resepectively, corresponding estimation is 97.359 GW by hydrothermal smoker and diffusive flow, 84.895 GW by hydrothermal plume, and 4.11 TW by exponential attenuation method put forward by this paper.Research on mass flux estimation is relatively rare, the main reason for this is insufficient field observation data.Mass fluxes of different elements are calculated using hydrothermal vent fluid data from the TAG hydrothermal area on the Mid-Atlantic Ridge for the first time.Difference of estimations by different methods reflects the researching extent of hydrothermal activity, and systematically in-situ observation will help to estimate the contribution of hydrothermal activity to ocean chemical environment, ocean circulation and global climate precisely.
Sedimentary facies and paleoenvironmental interpretation of a Holocene marsh in the Gironde Estuary in France
WANG Jianhua, MASSE Laurent, TASTET Jean-Pierre
2006, (6): 52-62.
The Monards Marsh is located on the northeastern bank of the Gironde Estuary in France.Lithological, sedimentological and micropalaeontological investigations were made on four cores to determine the evolution of Holocene sedimentary environments and processes in this area over the last 6 000 a.Three main lithological facies are distinguished from bottom to top:(1) grey laminated silty-sandy clay; (2) homogeneous dark grey silty clay; and (3) compact silty clay.About 26 benthic foraminifera species are identified and divided into six groups according to their ecological characteristics.In association with lithology, sedimentary structures and grainulometry, the distribution of foraminifera group is used to define external slikke, internal slikke, external schorre, internal schorre, and continental marsh facies.Combined with 14C (AMS) dating, these data indicate four successive paleoenvironments in the Monards Marsh:(1) Holocene transgression resulted in the development of a basal schorre facies overlying fluvial deposits that transformed to slikke facies sedimentation; the transgression maximum occurred around 5 600 to 5 400 a BP and was inferred to be associated with the last phase of the rapid Holocene sea-level rise; (2) post-trangressive maximum sedimentation resulted in a regressive sequence of deposits prograding towards the estuary, corresponding to the stabilisation of sea level after 5 400 a BP; (3) a slight positive tendency in the sea level around 2 800 a BP recorded in the central part of the marsh; and (4) the wetland to a continental marsh environment.The sequential pattern for the evolution of wetlands in this estuarine area during the Holocene is fluvial facies-blackish schorre facies-slikke facies-blackish schorre facies-continental marsh facies.Characteristics of sedimentary facies distribution and evolution reveal that the development of Holocene salt marsh in this area was controlled by the sea-level change and tidal range.The sedimentary facies show an obvious surficial and vertical banding distribution in which the texture and structure, authigenic mineral, foraminifera distribution and bioturbation indicate many distinct difference characteristics.
Grain-size distribution patterns of suspended sediment in response to hydrodynamics on the Dafeng intertidal flat, Jiangsu, China
LI Zhanhai, GAO Shu, CHEN Shenliang, WANG Yaping
2006, (6): 63-77.
Patterns of grain-size distributions of suspended sediment in relation to resuspension, settling, and tidal processes are investigated, based on in situ measurements over the Dafeng intertidal flat, on the Jiangsu coast, in the summer of 2002 and 2003.The suspended sediment here is dominated by fine and very fine silt, with a mean grain-size of 7~13 μm.The patterns of the grain-size distributions of suspended sediment during a tidal cycle are characterized by two types:one stable type representing insignificant spatial and temporal variations; and the other bimodal type with significant variations.The main factors influencing the grain-size distributions include resuspension, settling, suspended sediment imported into intertidal flats during the flood phase, and the grain-size distribution of seabed sediment.Resuspension increases the coarse particle content, enhances the mean grain-size of suspended sediment, and results in grain-size distributions for the suspended sediment similar to those of seabed sediment; the settling process has opposite effects on the suspended sediment.When resuspension occurs, the gain-size distributions of suspended sediment in the lower part of water column respond significantly to the current velocity.Where the influence of resuspension and settling processes is weak, the grain-size distributions of suspended sediment appear to be stable and almost identical for the various parts of intertidal flats during different measurement periods.Such distributions are referred to the background grain-size distribution, for which the mean grain-size over the Dafeng intertidal flat is around 7 μm.
Excess polonium-210 in the coastal atmosphere originating from marine biogenic material
YANG Weifeng, CHEN Min, HUANG Yipu, LIU Guangshan, JIA Chengxia
2006, (6): 78-87.
The depositional fluxes of atmospheric polonium-210 were measured at one site in Xiamen from August 2001 to March 2002.With predominant marine air mass, the depositional fluxes of atmospheric polonium-210 ranged from 0.01 to 0.09 Bq/(m2·d), with an average of 0.04 Bq/(m2·d).The seasonal pattern showed elevated polonium-210 fluxes in summer and autumn rather than in winter.Atmospheric depositional fluxes of polonium-210 showed a good correlation with beryllium-7 (r2=0.85) and lead-210 fluxes (r2=0.71), indicating their similar removal mechanism from atmosphere.The relationship between the polonium-210 depositional fluxes and the precipitation amount demonstrated that the precipitation dominates the polonium-210 removal from the atmosphere.The observed high activity ratios of polonium-210 to lead-210 indicated the occurrence of excess polonium-210 in coastal atmosphere, which may originate from marine surface waters either by indirect (foam), or more likely, direct (air-sea exchange) input of marine biogenic material into the atmosphere.This source is even more important than the in situ decay of lead-210.
Population dynamics of Acartia pacifica (Copepoda: Calanoida): the importance of benthic-pelagic coupling
JIANG Xiaodong, WANG Guizhong, LI Shaojing
2006, (6): 88-98.
The seasonal occurrence of Acartia pacifica (Copepoda:Calanoida) and their resting eggs in the sediment of Xiamen Bay were documented between October 2002 and September 2003.The number of viable eggs in the sediment increased from January to May with the increase in the number of planktonic females.When the population of A.Pacifica disappeared from the water column, the number of eggs in the sediment began to decrease and reached a low value due to lack of input.The peak of nauplii abundance occurred when the hatching potential of eggs from the sediment was high under the natural environment from February to June.The hatching of resting eggs of A.Pacifica was essentially temperature-dependent after suspension, while photoperiod regimes had no significant effect on the hatching.The mean density of subitaneous eggs was 1.122 0 g/cm3 with a standard deviation (SD) of 0.000 2 g/cm3.The mean density of diapause eggs was 1.151 2 g/cm3 with a SD of 0.000 1 g/cm3.The sinking rates of subitaneous eggs ranged from 19.55 to 26.17 m/d, while those of diapause eggs ranged from 30.29 to 31.28 m/d.The comparison of the egg deposition time and egg hatching time suggested that in most cases virtually all subitaneous eggs of A.Pacifica would settle to the bottom before their hatching even though the eggs have high potential to hatch.The evidence was provided that the seasonal dynamics of A.Pacifica is accompanied by benthic-pelagic coupling.
Expression, purification and polyclonal antibody generation of p23, an Hsp90 cochaperone, in the amphioxus Branchiostoma belcheri
ZHAO Bosheng, ZHANG Shicui, PANG Qiuxiang, LIU Zhenhui, LIANG Yujun
2006, (6): 99-105.
The cDNA of amphioxus p23, a highly conserved co-chaperone for Hsp90, was cloned into a bacterial expression vector pGEX-6P-1 and the GST-tagged fusion protein was produced in Eschherichia coli cells.The recombinant p23 was purified by affinity purification, and its molecular mass was estimated to be approximately 22 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.The N-terminus of purified p23 was sequenced, and the resulting amino acid sequence matches exactly the predicted residues deduced from the amphioxus p23 gene.Besides, polyclonal antibodies against the recombinant p23 were generated, and these antibodies not only recognized specifically the fusion protein GST-p23 from induced E.coli cells, purified GST-p23 and p23 protein, but also reacted with the total protein extracted from the adult amphioxus and formed a single positive band.These results pave the way for identifying its tissue and subcellular localization, and may open the door to clarifying its structure and mechanisms of biological role.
Production and characterization of an extracellular polysaccharide of antarctic marine bacteria Pseudoalteromonas sp. S-15-13
LI Jiang, CHEN Kaoshan, LIN Xuezheng, HE Peiqing, LI Guangyou
2006, (6): 106-115.
Twenty-seven antarctic bacteria producing extracellular polysaccharide (EPS) were selected from 57 strains by staining technology.The effects of major environmental factors on the growth and EPS production of Pseudoalteromonas sp.S-15-13 were investigated, and the EPS was separated and purified for characterization analysis.The results showed that the optimal conditions for the EPS production were culture period, 56 h; growth temperature, 8℃; carbon source, 1.0% glucose; NaCl concentration, 3.0%; pH 6.0~7.0.The EPS was purified by cold ethanol precipitation, proteins removal, ion exchange chromatography and gel chromatography technology.The molecular mass of EPS-Ⅱ was 62 kDa as determined by the high performance gel permeation chromatography.Its sugar composition was a homopolymer of mannose analyzed by gas chromatograph spectroscopy.After repeated freezing and thawing of the bacteria biomass in the presence of EPS, the bacterial growth was much higher than that observed after freezing in the absence of EPS and the difference augmented with the increase of freeze-thaw cycles.It is hypothesized that the adaptation of Pseudoalteromonas sp.S-15-13 to the antarctic marine conditions, characterized by low temperature, high NaCl concentration and repeated freeze-thaw cycles, might be related to the EPS production ability.
Draft effect on wave action with a semi-infinite elastic plate
TENG Bin, GOU Ying, CHENG Liang, LIU Shuxue
2006, (6): 116-127.
A method for analyzing reflection and transmission of ocean waves from a semi-infinite elastic plate with a draft is developed.The relation of energy conservation for plates with three different edge conditions (free, simply supported and built-in) is also derived.It is found that the present method satisfies the energy relation very well.The effects of draft on wave reflection and transmission coefficients as well as on the vertical vibration of the plates are examined through numerical tests.It is demonstrated that the zero draft assumption works well for low wave frequencies, but the effect of plate draft becomes significant for high wave frequencies.
Research Notes
LEADAT: a MATLAB-based program for lead-210 data analysis of sediment cores
LU Xueqiang, MATSUMOTO Eiji
2006, (6): 128-137.
The program described herein (LEADAT) serves to calculate sediment date and sedimentation rate using the 210Pb method for the studies of environmental processes and pollution history on a time scale of 100~150 a.The program written in MATLAB (Version7.0) permits the user to select the principal models of 210Pb method, I.e., the constant fluxes of sediment and lead-210 (CFSL) model, the constant flux of lead-210 (CFL) model, the constant initial concentration of lead-210 (CICL) model and the two-layer mixing (TLM) model.Although appropriate model selection is essentially based on understanding of the sedimentary processes, the pattern of the excess 210Pb profile is also helpful for model selection.The excess 210Pb profiles for two sediment cores collected from a brackish lake and an embayment respectively are used to demonstrate the application of the program.With a graphical user interface, the program can be easily executed.Not only ASCⅡ but also graphical output can be generated by means of the program.Meanwhile, the code can be modified easily for extension.
Environmental control of growth and BChl a expression in an aerobic anoxygenic phototrophic bacterium, Erythrobacter longus (DSMZ6997)
LI Qiang, JIAO Nianzhi, PENG Zaiqing
2006, (6): 138-144.
Aerobic anoxygenic phototrophic bacteria (AAPB), which form a unique functional group of heterotrophic bacteria, have the ability to utilize light energy.The impact of carbon source and light intensity on the growth and bacteriochlorophyll a (BChl a) expression of a typical strain of AAPB, Erythrobacter longus strain DSMZ6997 was examined during batch culture and continuous culture.The results showed that the expression of BChl a in DSMZ6997 was regulated by both carbon-source and light conditions, and was stimulated by low availability of carbon but inhibited by light to a certain extent at 300 lx and completely at 1 500 lx.In contrast, cell abundance, and even cell size of this strain, was substantially enhanced under light/dark cycle cultivation conditions over dark conditions, indicating the promotion of growth by light.These results led to the conclusion that utilization of light through BChl a helps AAPB to survive under carbon stress, while light at high intensity is harmful to the synthesis of BChl a in AAPB.
Genetic transformation of marine Actinomycete sp. isolate M048 and expression of a recombinant plasmid carrying the apc gene
HOU Yanhua, LI Fuchao, QIN Song, WANG Quanfu
2006, (6): 145-152.
Optimal conditions for protoplasts formation of marine Actinomycete sp.isolate M048 were described, dense and disperse mycelia were cultured in SGGP medium, 0.5% glycine, lysozyme exposure (2 mg/cm3, 37℃, 40 min), and the concentration of sucrose in protoplast buffer was 0.4 mol/dm3 for keeping the balance of osmotic pressure.Using PEG-mediated protoplasts transformation, the transformation frequency was 89 transformants per microgramme of pIJ702.Meanwhile, an effective transformation procedure was established based on intergeneric conjugation from E.coli ET12567 (pUZ8002) using shuttle vectors pPM801, pPM803 and a (ψ)C31-derived integration vector pIJ8600 containing ori T and att P fragments.Transformation frequencies were 5.30×10-4±0.26×10-4, 8.92×10-4±0.19×10-4 and 6.38×10-5±0.41×10-5, respectively.Further, the heterologous expression of the allophycocyanin gene (apc) in the strain M048 was used to demonstrate this transformation system.SDS-PAGE and Western blot analysis confirmed the expression of recombinant APC (rAPC).
Studies on the bioactivity of marine microorganisms using Pyricularia oryzae model
WEN Zhanbo, PEI Yuehu, TIAN Li, GAO Aiguo, HONG Xuguang, LI Xianchun
2006, (6): 153-161.
A total of 2 088 marine microorganisms including 1 392 strains of bacteria and 696 strains of fungi were isolated from diverse marine environment such as the South Pole, the North Pole, and Qingdao tideland, etc.Through a systematic screening process involving the use of Pyricularia oryzae mode, 90 bacteria and 31 fungi strains demonstrating positive bioactivities were identified.The rates of active strains of marine bacteria and marine fungi were 6.5% and 4.5%, respectively.The relationships between the active strains and the sampling locations and hosts were studied.For marine bacteria, the three locations showing the highest rates of active strains were 8.4% in the Zhujiang Estuary, 7.2% at the North Pole and 6.3% in the Bohai Sea.For marine fungi, the highest rates observed were 7.8% at the South Pole, 7.4% in the South China Sea and 6.8% at the Qingdao tideland.An analysis of the host showed that the three highest rates of active strain for marine bacteria were 8.2% for seawater from the Zhujiang Estuary, 8% for alga from the Qingdao tideland and 7.6% for sea mud from the North Pole.For marine fungi, the highest rates observed were 8.3% for Qingdao actiniae, 7.4% for South China Sea poriferan and 4.5% for soil of Qingdao Suaeda salsa.Four fungi and two bacteria samples were selected for further study because of their high bioactivity.They were found to be active towards several pathogenic microorganisms, and demonstrated stable genetic and thermal characteristics and conservation activities.