2007 Vol. 26, No. 1

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Articles
Retrieving the surface axis of the Kuroshio off southern coast of Japan from SST data
SHAO Quanqin, CHEN Zhuoqi, MA Weiwei
2007, (1): 1-11.
Abstract:
One thousand and forty-nine sea surface isotherm maps during 1990~2000 were used to detect the Kuroshio axis off the coast of Japan.The current axis on the surface cannot be identified by just one indicative isotherm as is commonly done in deep water, but still there are complicated isotherms indicatives of the Kuroshio axis.Three types of isotherms indicatives of the surface axis of the Kuroshio are identified, which are nesting-warm-tongue-indicator, warm-tongue-isotherm-indicator, and isotherm-indicator.The occurrence frequency of NWTI-type is 72%, that of WTⅡ-type is 19.1% and that of Ⅱ-type is 8.9%.The vector-based and raster-based methods were introduced and used to retrieve automatically the Kuroshio paths from SST data.The total retrieving percentage is 74% by the three methods, 52.3% by the vector method, 56.8% by one raster method and 49.6% by another raster method.For the NWTI-type, the total retrieving percentage is 91.3% by the three methods, 64.4% by the vector method, 75.9% by one raster method and 65% by another raster method.Using retrieving results of the Kuroshio axis from SST data, the Kuroshio path detour is analyzed during 1990~2000.
A global analysis of multi-mode sea surface temperature pattern
ZHANG Caiyun, CHEN Ge
2007, (1): 12-22.
Abstract:
The variability of the air-sea system in the low-frequency time domain can be decomposed into several systematic climate modes, namely, the decadal variability (DV) mode, the El Niño Southern Oscillation (ENSO) mode, the annual cycle (AC) mode, the semiannual cycle (SC) mode and the intraseasonal variability (ISV) mode.The combination of these primary modes in the air-sea system orchestrates a complex climate system.The multi-mode low-frequency variability in SST is investigated based on 22 a SST records from 1982 through 2003.The variation of SST in the past two decades undergoes a different combination of these dominant climate modes over different regions, which leads to an interesting new classification of the global ocean based on the relative importance of these modes.The new classification can provide ideal locations for better monitoring of these low-frequency modes in the scientific proof sense.Moreover, two no-annual variation and 14 no-semiannual variation oceanic points, termed annual and semiannual amphidromes, have been well defined in the AC and SC phase maps.The formation of these nodal points is attributed to the couplings of climate modes in EOF analysis results.
Analysis and prognosis of tropical cyclone genesis over the western North Pacific on the background of global warming
LI Yongping, WANG Xiaofeng, YU Runling, QIN Zenghao
2007, (1): 23-34.
Abstract:
As revealed by the observational study, there are more tropical cyclones generated over the western North Pacific from the early 1950s to the early 1970s in the 20th century and less tropical cyclones from the mid-1970s to the present.The decadal change of tropical cyclones activities are closely related to the decadal changes of atmospheric general circulation in the troposphere, which provide favorable or unfavorable conditions for the formation of tropical cyclone.Furthermore, based on the simulation of corresponding atmospheric general circulation from a coupled climate model under the schemes of Intergovernmental Panel on Climate Change (IPCC) special report on emission scenarios (SRES) A2 and B2 emissions scenarios an outlook on the tropical cyclone frequency generated over the western North Pacific in the coming half century is presented.It is indicated that in response to the global climate change the general circulation of atmosphere would become unfavorable for the formation of tropical cyclone as a whole and the frequency of tropical cyclones formation would likely decrease by 5% within the next half century, although more tropical cyclones would appear during a short period in it.
Wave-tide-surge coupled model simulation for Typhoon Maemi
CHOI Byung Ho, KIM Dong Chule, KIM Young Bok, KIM Hyun Seung
2007, (1): 35-47.
Abstract:
Reasonably accurate predictions of wave heights, current and elevations during storm events are vital information for marine operations and design of offshore and coastal structures in the surrounding seas of Korea Peninsula.Ocean circulation and wind-wave models have traditionally been run separately, but recent researches have identified potentially important interactions between current and wave motions.The coupled tide-surge and the WAM wave models at the atmospheric boundary layer and bottom boundary layer around the Korea Peninsula are applied for the Typhoon Maemi (0314) event.Communication between the models is achieved using MPI.Results are compared with coastal tide gauges and moored wave buoys and comparisons are also made between wave computations from the coupled model and the independent third generation wave models.Results suggest that applying the tide-surge-coupled model can be an effective means of obtaining wave and storm surge predictions simultaneously.
Underwater topography detection of Shuangzi Reefs with SAR images acquired in different time
YANG Jungang, ZHANG Jie, MENG Junmin
2007, (1): 48-54.
Abstract:
Imaging mechanism of underwater topography by SAR and a underwater topography SAR detection model built on the theory of underwater topography detection with SAR image presented by Yuan Yeli are used to detect the underwater topography of Shuangzi Reefs in the Nansha Islands with three scenes of SAR images acquired in different time.Detection results of three SAR images are compared with the chart topography and the detection errors are analyzed.Underwater topography detection experiments of Shuangzi Reefs show that the detection model is practicable.The detection results indicate that SAR images acquired in different time also can be used to detect the underwater topography, and the detection results are affected by the ocean conditions in the SAR acquiring time.
Measurements of suspended particulate matter with laser in-situ scattering and transmissometry in the Jiaozhou Bay in China
WEI Jianwei, SHI Xuefa, FANG Xisheng, ZHANG Weibin
2007, (1): 55-65.
Abstract:
A laser in-situ scattering and transmissometry probe (LISST-100) was used to estimate the spatial variations of suspended particle (aggregate) distribution, volume concentration and beam attenuation in the Jiaozhou Bay, Qingdao, China on 18 July 2003.One study site was located at the mouth (Sta.J1), with the other being within the inner bay (Sta.J2).Measurements of total suspended matter (TSM) and chlorophyll fluorescence and sampling of bottom sediments were carried out simultaneously.On the basis of the field data, the in-situ particle effective density, settling velocity and flux, and particle projected surface area (PSA) were estimated.The results demonstrate that both profiles have similar particle size distributions from surface to bottom within the water columns.Mean particle diameters for Stas J1 and J2 are 38~74 and 1~20 μm, respectively, particles within these ranges dominate over the particulate components.Suspended particle volume concentrations increase with water depth, with spikes near the bottom.At Sta.J1, the mean size of bottom sediments and those of suspended particles at 10.8 m below the water surface are almost the same, as well as their size distributions.This observation suggests that a special affinity exists between bottom sediment and suspended particles.In addition, the estimates show that the effective density, settling velocity and flux are higher in the inner bay.Beam attenuation coefficient correlates well with the volume concentration, positively.It is inferred that the optical scattering was mostly caused by 1~250 μm components, among which the particles finer than 20 μm dominate the beam attenuation.The PSA appears a proxy for the leaving reflectance estimation.
Mineral provinces and material provenance of the surficial sediments near the Zhongsha Islands in the South China Sea
YAN Quanshu, SHI Xuefa, WANG Kunshan
2007, (1): 66-76.
Abstract:
Characteristics and distribution patterns of clastic minerals (0.063~0.125 mm) in bottom sediments represent a significant indicator for the identification of the origin of sediment.One hundred and fourteen surface sediment samples, which were collected from the area near the Zhongsha Islands in the South China Sea, were analysed to identify the mineral suites and their distributions in the study area.The area can be divided into three mineral provinces:(Ⅰ) a province of biogenic minerals, which mainly originate from the Zhongsha Atoll; (Ⅱ) a province of volcanogenic minerals, which are mainly derived from local basaltic seamounts and small-scale volcanoes that are probably erupting, with some influences from the island-arc volcanic region around the South China Sea; and (Ⅲ) a mixed mineral province whose material source includes biogenic minerals, volcanogenic minerals and terrigenous minerals; the last province can be subdivided into a mixed mineral sub-province of the northeastern part of the study area, in which terrigenous minerals are mainly derived from China's Mainland and do not exceed 17°N, and a mixed mineral sub-province of the southeastern part of the study area, in which terrigenous minerals are derived from Kalimantan and Indochina Peninsula and might be further transported into the deep sea basin through submarine canyons.
On new species and records of Hydroidomedusae from the Changjiang River Estuary and its adjacent waters
XU Zhenzu, HUANG Jiaqi, LIU Guangxing
2007, (1): 77-83.
Abstract:
Forty-nine species of Hydroidomedusae are identified.Two new species and new records are described.
The prewarning value of Alexandrium tamarense PSP in an area with frequent outburst of red tide
JI Weidong, ZHOU Qiulin, HUO Wenmian, CHEN Weifen, LIN Hui, HE Qing, CHEN Baohong, LIANG Junrong, GAO Yahui, HUANG Deqiang, LI Yang
2007, (1): 84-92.
Abstract:
The PSP toxicity of Alexandrium tamarense (Lebour) Balech on the blue mussel (Mytilus edulis) from the western waters of Xiamen in China was studied by following the standard method of PSP mouse bioassay developed by the Association of Official Analytical Chemists (AOAC).The results showed that the mice survived when the density of A.tamarense cells was lower than 1×105 cells per cubic decimetre and died when the density was higher than 1×106 cells per cubic decimetre.The past record of red tide events in the western waters of Xiamen showed a general trend of starting from the bloom of non-toxic planktonic diatoms in local waters and resulting in a harmful algal bloom due to the fade of planktonic diatoms which failed in the survival competition in the unfavorable and deteriorated eco-environment.On the basis of experimental results and natural environment of Xiamen waters and by making reference to the critical criteria of shellfish toxins in various states, a prewarning value 1×105 cells per cubic decimetre of A.tamarense PSP toxicity was proposed for the areas in South China where red tides frequently occur.
Application of the first internal transcribed spacer(ITS-1) of ribosomal DNA as a molecular marker to population analysis in farrer's scallop Chlamys farreri
YU Ziniu, WEI Xiaohua, KONG Xiaoyu, YU Shanshan
2007, (1): 93-100.
Abstract:
Sequence variation of the first internal transcribed spacer of ribosomal DNA (ITS-1) was examined and its application to the study of genetic variation was explored in four populations of farrer's scallop Chlamys farreri.ITS-1 fragments, with a length of about 300 bp, of 78 individuals collected from Dalian, Qingdao, Yantai in China and Korea respectively were amplified via PCR, cloned and sequenced.Intra-genomic variation was examined by sequencing several clones of single individuals.Alignment and polymorphism analysis detected 44 haplotypes and 50 polymorphic sites which consist of 30 substitutions and 20 indels, indicating a high level of polymorphisms.Sequence analysis also showed a very low level of intra-individual variation.All these features validated the feasibility of application of ITS-1 fragment to population analysis.Polymorphism analysis showed that the Korea sample has the richest genetic variation, followed by Yantai and Qingdao samples.AMOVA (analysis of molecular variance) showed that the majority (96.26%) of genetic variation was distributed within populations and 3.74% resulted from among populations, but with P<0.05 (=0.042), indicating that the populations in this study have significant divergence.This output was basically concordant with the result arising from RAPD data and different from that from mitochondrial 16S rDNA sequence data.Discussion on this inconsistency was made accordingly.
Protective immunity of orange-spotted grouper(Epinephelus coioids) against a nervous necrosis virus isolated from China,and determination of the complete sequences of the virus
CHEN Xiaoyan, WENG Shaoping, CHEN Shengping, CHEN Zhaoming, HE Jianguo
2007, (1): 101-111.
Abstract:
On the basis of the sequence and analysis of genome from the orange-spotted nervous necrosis virus (OGNNV), China strain, a pair of special primers were designed according to the nucleotide sequences of RNA2 from OGNNV.The major capsid protein (MCP)gene of OGNNV was cloned by means of reverse-transcriptase polymerase chain reaction (RT-PCR)and ligated into the pET32a expression plasmid.The MCP gene of OGNNV was 1 017 bases, encoded a protein of 338 amino acid with a molecular mass of 37.1 kDa.Recombinant protein with a molecular mass of 57.4 kDa was expressed in E.coli BL21 (DE3).Vaccine was prepared from the recombinant protein expressed in recombinant cells.The juvenile orange-spotted groupers (8 cm in average length) were immunized by intraperitoneal injection.Group A was challenged with infected tissue filtrates 25 d post-vaccination.The mortality in the vaccined group (A1, 30%) was a little higher than the unvaccined group (B2, 27.8%).Group B was challenged after three vaccine injections.The mortality in the vaccined group (B1, 16.7%) was lower than the unvaccined group (B2, 27.8%), And the relative percentage survival (RPS) value of vaccined group, compared with the unvaccined group, was 40%.The anti-recombinant protein sera with a 1:100 dilution were mixed with double volume of infected tissue filtrates and incubated at 4℃ for 12 h and then intramuscularly injected into the juvenile orange-spotted grouper.Treatment of infected tissue filtrates with anti-recombinant protein serum resulted in a significantly lower mortality of fish (Group C1, mortality of 18.18%), compared with the fish (Group C2, mortality of 40%) which received infected tissue filtrates treated with control serum.Results implied the potential use of the capsid protein in immunization against OGNNV.
Effect of dietary docosahexaenoic acid on lipogenesis and lipolysis in black sea bream, Acanthopagrus schlegeli
JI Hong, OM Ahamd Daud, YOSHIMATSU Takao, UMINO Testuya, NAKAGAWA Heisuke, FURUHASHI Makoto, SAKAMOTO Shuichi
2007, (1): 112-121.
Abstract:
Hatchery-reared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish.To assess the effect of docosahaxaenoic acid (DHA) on lipogenic and lipolysis enzymes, one-year fish were reared on a casein-based purified diet and a DHA fortified diet (1.5% DHA ethyl ester/kg diet) for 60 d, followed with a period of 55 d for starvation.Dietary DHA was effectively incorporated into the fish body.Fortification of DHA depressed activities of glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase as lipogenic enzymes in the hepatopancreas and intraperitoneal fat body.Carnitine palmitoyltransferase as lipolysis enzyme in the hepatopancreas was active in the DHA fortified fish.Starvation after feeding experiment induced increased carnitine palmitoyltransferase activity in both control and DHA fortified fish and the activity remained higher in the DHA fortified fish, while the monoenes were selectively consumed prior to highly unsaturated fatty acids.These results indicated that dietary DHA depressed lipogenesis and activated lipolysis.
Identification of Epinephelus malabaricus and Epinephelus coioides using DNA markers
WANG Shifeng, DU Jiaying, WANG Jun, DING Shaoxiong
2007, (1): 122-129.
Abstract:
Using multi-molecular marker technologies and based on morphological criteria, the genetic relationship between Epinepheelus malabaricus and E.coioides was examined in the hope of resolving the long-standing issue of identifying these two species.Results showed that:(1) E.coioides and E.malabaricus should be identified as two species, the consistency of mitochondrial DNA cytochrome b gene sequence between E.malabaricus and E.coioides is 94.4%, and the genetic similarity by AFLP was 0.753 9; (2) Hybridization exists between E.malabaricus and E.coioides, the specific RAPD and AFLP fragments are found to be useful in the identification of these two species, and the genetic properties (both with exterior and inheritance) of hybrid is significantly biased to the male parents; and (3) AFLP was a potentially powerful tool in constructing the genetic linkage map for these two groupers.
An experimental investigation of the velocity field under cnoidal waves over the asymmetric rippled bed
CHENG Yongzhou, WANG Yongxue, JIANG Changbo, CHEN Chun
2007, (1): 130-139.
Abstract:
The evolution of an initially flat sandy bed is studied in a laboratory wave flume under cnoidal waves and acoustic Doppler velocimeter (ADV) was utilized in the detailed velocity measurements at different positions.The ripple formation and evolution have been analyzed by CCD images and the asymmetric rippled bed is induced by the nonlinear wave flow.The flow structure and a complete process of vortex formation, evolvement and disappearance were observed on the asymmetric rippled bed under cnoidal waves.With the increasing nonlinearity of waves, which is an important factor in the sand ripple formation, the vortex intensity becomes stronger and shows different characteristics on both sides of the ripple crest.The vorticity and wave velocity reach their maximum values at different phase angles.The vortex value reaches the maximum value at a small phase angle with the increasing Ursell number.The near bed flow patterns are mainly determined by the ripple forms and the averaged longitudinal velocity over a wave period above the ripple trough and crest are positive, which indicates the possibility of significant onshore sediment transport and a corresponding ripple drift.The phase averaged vertical velocity has noticeable positive values near the bottom of the ripple crest and trough.Sediments may be lifted from the ripple surface, picked up in suspension by the local velocity, and deposited over the crest and on the lee of the ripples.
Flocculation process of fine-grained sediments by the combined effect of salinity and humus in the Changjiang Estuary
LIU Qizhen, LI Jiufa, DAI Zhijun, LI Daoji
2007, (1): 140-149.
Abstract:
For the great amount of organic compounds and the variation of salinity in the Changjiang Estuary, the study on the flocculation process of fine-grained sediments by the combined effect of salinity and humus in the high-turbid system is of critical significance for the understanding of the mechanism of the formation of the turbidity maximum (TM).For the great amount of organic compounds and the variation of salinity in the Changjiang Estuary, the study on the flocculation process of fine-grained sediments by the combined effect of salinity and humus in the high-turbid system is of critical significance for the understanding of the mechanism of the formation of the turbidity maximum (TM).The effects of salinity and humus on the fine-grained sediments have been analyzed through the synthetic study of the aspects of flocculation/coagulation power (F), diameter (D) and zeta potential (Z).And the microcosmic configuration of the flocs has been analyzed by using a scan electron microscope and Fourier Transform Infrared Spectrometry.The results show that:(1) with the increase of salinity, F and D become greater and Z becomes smaller, and with the increase of the concentration of humus, F becomes smaller, but D and Z become greater; (2) the microcosmic configuration of the flocculation shows that humus packs on the fine sediments in the form of salt, and the flocculation model of C-P-OM (C stands for clay; P cations; OM organic materials) can successfully demonstrate the mechanism of the formation of the fine-grained sediments in the high-turbid area of the Changjiang Estuary.
Research Notes
AFLP analysis revealed differences in genetic diversity of four natural populations of Manila clam(Ruditapes philippinarum) in China
LIU Xiangquan, BAO Zhenmin, HU Jingjie, WANG Shi, ZHAN Aibin, LIU Hui, FANG Jianguang, WANG Rucai
2007, (1): 150-158.
Abstract:
The amplified fragment length polymorphism (AFLP) technology was used to analyze the genetic diversities in four natural populations of Manila clam (Ruditapes philippinarum), distributed in four sea areas of China, i.e., the Bohai Sea, the Huanghai Sea, the East China Sea and the South China Sea.Two hundred and sixty-four AFLP loci were analysed in 195 individuals and revealed high levels of genetic diversity.The percentage of polymorphic loci ranged from 92.13% to 96.06% and the Shannon's information index was from 0.256 8 to 0.275 6.By analyzing molecular variance (AMOVA), it was found that there were high levels of genetic differentiation between populations of Qingdao and the other three sea areas.Cluster analysis by Nei's pairwise distances grouped specimens by geographical origin, except the population of Qingdao.A conclusion can be drawn that there are high genetic diversities in the four natural populations of Manila clam in China and some distinct differences existed among and between the four populations.The results also indicated that human cultivation activities will have great influence on the genetic structure of the population of Qingdao.
Identification of SNARE proteins in fish-Tilapia Oreochromis niloticus
HUANG Xiaohang, LAM Patrick P L, LIN Xuezheng, LIU Chenlin, BIAN Ji, GAISANO Herbert
2007, (1): 159-164.
Abstract:
SNARE proteins are a group of membrane-associated proteins involved in exocytosis, secretion and membrane trafficking events in eukaryotic cells.Research on SNARE protein biology has become a more attractive field in recent years, which is applied to marine biology specifically to the fish Tilapia (Oreochromis niloticus).Plasma membrane fractions of different tissues of Tilapia, including brain, liver-pancreas, intestine, skin and muscle, were extracted, and immuno-decorated with isoform-specific antibodies to the SNARE families and associated proteins.The presence of Syntaxins -1A, 2 and 3, SNAP-23 and SNAP-25, VAMP-2, Munc-18-1 and Munc-13 in the brain was identified, which were differentially distributed in the other organ tissues of the fish Tilapia.The distinct distribution of SNARE and associated proteins will serve as the basis for further investigation into their special secretory function in these tissues of the fish.