# Acta Oceanologica Sinica -English Edition-

Online ISSN: 0253-505X
Publications
Article
The present study is based on the sedimentological data from a piston core KCES1 off the southern Ulleung Basin margin, the East Sea (Sea of Japan). The data include sediment color (L*), X-ray radiographs, grain size distribution and AMS14C date. Four kinds of sediments (homogeneous, laminated, crudely laminated and hybrid sediments) are identified according to the characters of the sedimentary structures that were considered to reflect changes in bottom-water oxygenation. Alternations of dark laminated/crudely laminated sediments and light homogeneous sediments represent millennial-scale variations that are possibly associated with the high-resolution changes in the East Asian monsoon (EAM). The relative contributions of the East China Sea Coastal Water (ECSCW) and the Tsushima Warm Current (TWC) were likely the main reasons for the repetition of the anoxic and oxic depositional conditions in the East Sea since the last 48 ka BP. During the interstadial, the strengthen summer EAM was attributed to the expansion of the ECSCW because of more humid climate in central Asia, and then more strongly low-salinity, nutrient-enriched water was introduced into the East Sea. The ventilation of deep water was restricted and therefore the dark laminated layer deposited under the anoxic bottom water condition. During the lowest stand of sea level in the last glacial maximum (LGM), the isolated East Sea dominated by stratified water masses and the euxinic depositional environment formed. The homogenous sediments have been predominating since 17.5 ka BP indicating that the TWC has intruded into the East Sea gradually with the stepwise rise of sea level and the bottom water oxygen level was high. During the late Younger Dryas (YD) period, the last dark laminated layer deposited because the ventilation of bottom water was restricted by stronger summer EAM. The TWC strengthened and the bottom water became oxic again from 10.5 ka BP.

Article
Altimeter and in situ data are used to estimate the mean surface zonal geostrophic current in the section along 115°E in the southern Indian Ocean, and the variation of strong currents in relation to the major fronts is studied. The results show that, in average, the flow in the core of Antarctic Circumpolar Current (ACC) along the section is composed of two parts, one corresponds to the jet of Subantarctic Front (SAF) and the other is the flow in the Polar Front Zone (PFZ), with a westward flow between them. The mean surface zonal geostrophic current corresponding to the SAF is up to 49 cm·s−1 at 46°S, which is the maximal velocity in the section. The eastward flow in the PFZ has a width of about 4.3 degrees in latitudes. The mean surface zonal geostrophic current corresponding to the Southern Antarctic Circumpolar Current Front (SACCF) is located at 59.7°S with velocity less than 20 cm·s−1. The location of zonal geostrophic jet corresponding to the SAF is quite stable during the study period. In contrast, the eastward jets in the PFZ exhibit various patterns, i.e., the primary Polar Front (PF1) shows its strong meridional shift and the secondary Polar Front (PF2) does not always coincide with jet. The surface zonal geostrophic current corresponding to SAF has the significant periods of annual, semi-annual and four-month. The geostrophic current of the PFZ also shows significant periods of semi-annual and four-month, but is out of phase with the periods of the SAF, which results in no notable semi-annual and fourmonth periods in the surface zonal geostrophic current in the core of the ACC. In terms of annual cycle, the mean surface zonal geostrophic current in the core of the ACC shows its maximal velocity in June. Key wordssouthern Indian Ocean–Antarctic Circumpolar Current–zonal geostrophic current–front

Article
Riverine carbon input is closely related to the inshore aquatic environment, the marine carbon pool and climate change. Samples were synchronously obtained from 16 rivers discharging into the Bohai Sea (China) in 1–5 July 2005. The dissolved organic carbon (DOC) concentrations of the 16 rivers were mainly controlled by anthropogenic activities. The particulate organic carbon (POC) of the Haihe, Luanhe, Ziyaxinhe, Chaobaixinhe, Xiaoqinghe, Xiaolinghe, Duliujianhe, Jiyunhe, and Majiahe Rivers mainly originated from pollutants discharged by human, while that of the Huanghe River (Yellow River), Daliaohe, Shuangtaizihe, Tuhaihe, Dalinghe, Daqinghe, and Liuguhe Rivers were generated mainly by soil erosion. Higher dissolved inorganic carbon (DIC) concentrations in the 16 rivers were detected, which were influenced by the large amounts of carbonate and industrial pollution. The estimated DOC, POC and DIC fluxes from the 16 rivers discharging into the Bohai Sea in summer, 2005 were 0.91×105, 1.23×105 and 6.31×105t, respectively. Key wordsBohai Sea–carbon fluxes–dissolved organic carbon–particulate organic carbon–carbon cycling–sources

Article
A two-month study was conducted to test the effects of macroalgae on the growth and survivorship of juvenile lined seahorse (Hippocampus erectus) in aquaria. Twenty-day old seahorses were cultured in the tanks with green alga Chaetomorpha linum, red alga Gracilaria tikvahiae, green plastic artificial plant (stargrass), and black plastic net, respectively. Increases in wet mass and standard length for the seahorses were significantly higher in the tanks with macroalgae than those without macroalgae. The seahorse survivorships in the two macroalgal treatments were also significantly higher than those of the two treatments without macroalgae. In the treatments with macroalgae, the DO and pH were higher than those without marcoalgae. During the experiment, the color of seahorses was changed to certain extent. In the green background (the treatments with C. linum and stargrass), 24.1%–28.4% of black seahorses decreased over time; whereas in the black (plastic net) or brown (G. tikvahiae) background treatments, 14.1%–16.3% of yellow seahorses decreased over time, for matching that of the background. Furthermore, the survival rate of seahorse was correlation with DO and pH, and strong correlation with standard length, wet mass and CF. Polyculture with macroalgae, survival rates of seahorse were higher than without macroaglae. Key words Hippocampus erectus - Chaetomorpha linum - Gracilaria tikvahiae -growth rate-survival rate-water quality in aquarium

Article
The sea surface temperature (SST) of the East China Sea (ECS) increased in the past decades, which may have a great impact on the ecosystem of the ECS, including the changes in planktonpopulation structure. In this paper, the changes in peaked abundance of Calanus sinicus in the Changjiang River (Yangtze River) Estuary were compared between 1959 and 2002, based on the data collected from the seasonally oceanographic cruises and those performed in spring of 2005. It was much higher in spring compared with that in other seasons both in 1959 and 2002. Furthermore, in spring 2005, the time for occurrence and decrease of the peaked C. sinicus abundance advanced about one month, accompanying the increase in the sea surface water temperature (SST). It peaked in June and decreased in July in 1959, however, in 2005, it peaked in May and attenuated sharply in early June. The earlier decrease of peaked C. sinicus abundance may further deteriorate the ecosystem in the Changjiang River Estuary and north nearshore of the ECS. Key words Calanus sinicus –East China Sea (ECS)–temperature–Changjiang River (Yangtze River) Estuary–zooplankton

Article
Based on Total Ozone Mapping Spectrometer (TOMS) monthly aerosol optical thickness (AOT) measurements in 1980–2001 a study is made of space/time patterns and difference between land and sea of AOT 0.50 µm thick over China, which are put into correlation analysis with synchronous extreme temperature indices (warm/cold day and night). Results suggest that 1) the long-term mean AOT over China is characterized by typical geography, with pronounced land-sea contrast. And AOT has significant seasonality and its seasonal difference is diminished as a function of latitude. 2) On the whole, the AOT displays an appreciably increasing trend, with the distinct increase in the eastern Qinghai-Tibetan plateau and SW China, North China, the mid-lower Changjiang (MiLY) valley as well as the South China Sea, but marginal decrease over western/northern Xinjiang and part of South China. 3) The AOT over land and sea is marked by conspicuous intra-seasonal and -yearly oscillations, with remarkable periods at one-, two-yr and more (as interannual periods). 4) Land AOT change is well correlated with extremely temperature indexes. Generally, the correlations of AOT to the extreme temperature indices are more significant in Eastern China with 110°E as the division. Their high-correlation regions are along the Southern China coastline, the Loess Plateau and the Sichuan Basin, and even higher in North China Plain and the mid-lower Changjiang River reaches. 5) Simulations of LMDZ-regional model indicate that aerosol effects may result in cooling all over China, particularly in Eastern China. The contribution of aerosol change may result in more decrease in the maximum temperature than the minimum, with decrease of 0.11/0.08 K for zonal average, respectively. Key wordskaerosol optical thickness–extreme temperature index–space/time pattern–trend–correlation

Article
A coastal upwelling event in the southern Taiwan Strait (STWS) was investigated using intensive cruise surveys (four repeated transects in a month) and satellite data in July and early August 2004. The extensive upwelling-associated surface cold water was first observed in early July (∼2.0×104 km2) along the STWS coast. Then, the cold surface water reduced in size by ∼50% with decreased chlorophyll concentrations after 15 days, indicating the weakening of the upwelling event. At the end of July, the cold surface water disappeared. The temporal variations of the surface cold water and the 3-D hydrography around Dongshan Island are thought to be mainly attributed to the weakened upwelling-favorable southwestern wind, the asymmetric spatial structure of the wind field and the intrusion of warm water from the northern South China Sea. Key wordscoastal upwelling–evolution–SST–ocean color–remote sensing–Taiwan Strait

Article
During spring and autumn of 2006, the investigations on abundance, carbon biomass and distribution of picoplankton were carried out in the southern Huanghai Sea (Yellow Sea, sHS). Three groups of picoplankton-Synechococcus (Syn), Picoeukaryotes (PEuk) and heterotrophic bacteria (BAC) were identified, but Prochlorococcus (Pro) was undetected. The average abundance of Syn and PEuk was lower in spring (5.0 and 1.3×103 cells/cm3, respectively) than in autumn (92.4 and 2.7×103 cells/cm3, respectively), but it was opposite for BAC (1.3 and 0.7×106 cells/cm3 in spring and autumn, respectively). And the total carbon biomass of picoplankton was higher in spring (37.23±11.67) mg/m3 than in autumn (21.29±13.75) mg/m3. The ratios of the three cell abundance were 5:1:1 341 and 30:1:124 in spring and autumn, respectively. And the ratios of carbon biomass of them were 5:7:362 and 9:4:4 in spring and autumn, respectively. Seasonal distribution characteristics of Syn, PEuk, BAC were quite different from each other. In spring, Syn abundance decreased in turn in the central waters (where phytoplankton bloom in spring occurred), the southern waters and inshore waters of the Shandong Peninsula (where even Syn was undetected); the high values of PEuk abundance appeared in the central and southern waters and the inshore of the Shandong Peninsula; the abundance of BAC was nearly three order of magnitude higher than that of photosynthetic picoplankton, and high values appeared in the central waters. In autumn, Syn abundance in central waters was higher than that in surrounding waters, while for PEuk abundance, it decreased in turn in the inshore waters of the Shandong Peninsula, the southern waters and the central waters; BAC presented a complicated blocky type distribution. Sub-surface maximum of each group of picopalnkton appeared in both spring and autumn. Compared with the available literatures concerning the studied area, the range of Syn abundance was larger, and the abundance of BAC was higher. In addition, the conversion factors for calculating picoplanktonic carbon biomass were discussed, with the conversion factors which are different from previous studies in the same surveyed waters. The result of regression analysis showed that there was distinct positive correlation between BAC and photosynthetic picoplankton in spring (r=0.61, P<0.001), but no correlation was found in autumn. Key wordssouthern Huanghai Sea-photosynthetic picoplankton-heterotrophic bacteria-abundance and carbon biomass distribution

Article
The wide presence of internal solitary waves (ISWs) in the northern South China Sea (SCS) has been confirmed by both Synthetic Aperture Radar (SAR) images and in situ observations. These ISWs are believed being generated over the varying topography in the Luzon Strait. They typically propagate westwards into the SCS with a diurnal or semidiurnal period. Their generation sites are, however, not yet solidly identified. To obtain a clear picture of the ISWs, we designed numerical experiments to analyze the generation and propagation of the ISWs in the Luzon Strait using a 2-dimensional non-hydrostatic model. The model current is forced by barotropic or baroclinic currents imposed at open boundaries. The experiments show that the tidal current serves as a kind of triggering force for the ISWs over the submarine ridges in the strait. Under the forcing of tidal currents, depressions are formed near the ridges. The ISWs then split from the depressions through a process different from lee-wave generation mechanism. The appearance of the ISWs is influenced by the strength and period of the forcing current: the ISWs are more likely to be generated by a stronger tidal current. That is why the ISWs in the Luzon Strait are frequently observed during spring tide. Compared with diurnal tidal current, the ISWs generated by semidiurnal tidal current with the same amplitude is much more energetic. It is partly because that the wave beams in diurnal frequency have a larger angle with the vertical direction, thus are more likely to be reflected by the topography slope. The impact of the Kuroshio to the ISWs is also analyzed by adding a vertical uniform or shear current at boundaries. A vertically uniform current may generate ISWs directly. On the other hand, a vertically shear current, which is more realistic to represent the Kuroshio branch, seems to have little influence on the generation process and radiating direction of the ISWs in the Luzon Strait.

Article
A new method of detecting abnormal sounding data based on LS-SVM is presented. The theorem proves that the trend surface filter is the especial result of LS-SVM. In order to depict the relationship of trend surface filter and LS-SVM, a contrast is given. The example shows that abnormal sounding data could be detected effectively by LS-SVM when the training samples and kernel function are reasonable. Key wordsLS-SVM–trend surface filter–kernel function–abnormal sounding data

Article
Distribution and abundance of Pseudeuphausia sinica off the Changjiang River Estuary (30 °00′-32°00′N, 122°00′-123°30′E), the East China Sea were studied in relation to environmental features associated with the regional warming. P. sinica is a subtropical species. Off the Changjiang River Estuary, its abundance reached maximum in summer. To examine spatial and temporal changes of P. sinica off the Changjiang River Estuary, the authors have combined all available sampling data in 1979, 1981, and 2000–2007. This database shows that a significant increase in abundances of P. sinica was observed in spring of 2000–2007 as compared with 1979, 1981. The abundance of P. sinica increased from 0.18–0.21 ind./m3 in 1979 and 1981 to 0.68–4.00 ind./m3 in 2000–2007. Accordingly, the sea temperature increased obviously from spring of 1979, 1981 to the 2000s. The authors further found a positive relationship between average surface temperature and average abundance of P. sinica. Regional warming, together with the release of predator induced stress due to a sharp decline in the abundance of its predator (e.g., fishes), were thought to be responsible for the increase in abundance of P. sinica in water off the Changjiang River Estuary. Key wordsChangjiang River (Yangtze River) Estuary–East China Sea– Pseudeuphausia sinica –temperature adaptation–zooplankton

Article
The community composition, abundance and culturablity of heterotrophic bacterioplankton in the Dapeng Bay of the South China Sea were investigated by morphological method, bacterial cultivation and biochemical methods over an annual cycle. Aeromonas and Pseudomonas were the predominant genera among the Gram-negative bacteria. The bacterioplankton abundance fluctuated from 2.07×108 to 2.44×109 cells/dm3, and culturable bacteria abundance ranged between 0.1×106 and 16.07×106 CFU/dm3. The Culturablity of heterotrophic bacteria ranged between 0.01% and 1.31%. The relationship between bacterial culturablity and the environmental factors was also studied in different sites of the Dapeng Bay. Throughout the bay, a significantly positive relationship was evidenced between bacterial culturability and temperature, meanswhile bacterial culturability was significantly inversely related with salinity. The positive relationship was shown at the central bay while a negative relationship was observed at the bay mouth and there was no significant correlation at top bay between bacterial culturablity and chlorophyll a of sea water. A positive relationship was found between culturability and DIN all the bay, but DIP showed a significantly negative relationship with bacterial culturability only at the mouth of the bay. Key wordsheterotrophic bacteria-culturable bacteria-culturablity-environmental factors

Article
underwater topography is one of oceanic features detected by Synthetic Aperture Radar. Underwater topography SAR imaging mechanism shows that tidal current is the important factor for underwater topography SAR imaging. Thus under the same wind field condition, SAR images for the same area acquired at different time include different information of the underwater topography. To utilize synchronously SAR images acquired at different time for the underwater topography SAR detection and improve the precision of detection, based on the detection model of underwater topography with single SAR image and the periodicity of tidal current, a detection model of underwater topography with a series of SAR images acquired at different time is developed by combing with tide and tidal current numerical simulation. To testify the feasibility of the presented model, Taiwan Shoal located at the south outlet of Taiwan Strait is selected as study area and three SAR images are used in the underwater topography detection. The detection results are compared with the field observation data of water depth carried out by R/V Dongfanghong 2, and the errors of the detection are compared with those of the single SAR image. All comparisons show that the detection model presented in the paper improves the precision of underwater topography SAR detection, and the presented model is feasible. Key wordsunderwater topography-SAR image-Taiwan Shoal-tide and tidal current

Article
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 two-way 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, Δ +) 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 (Δ) 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 (Δ*) 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.

Article
Chemometric approach based on principal component analysis (PCA) was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River (Pearl River) Estuary and adjacent waters (ZREAW) in the South China Sea. The PCA result shows that the ZREAW can be divided into different zones according to the principal components and geographical locations of the study stations, and indicates that there are distinct regional variances on environmental features and the corresponding phytoplankton biomass and community structures among different areas. The spatial distribution of ecological features was implied to be influenced by various degrees of the different water resources, such as the Pearl River discharges, the coastal current and the oceanic water from the South China Sea. The variation of the biomass maximum zone and the complex impacts on the spatial distributions of phytoplankton biomass and production were also evaluated. Key wordsprincipal component analysis–spatial variations–environmental conditions–ecological distribution–phytoplankton–Zhujiang River (Pearl River) Estuary

Article
A three-dimension ecological dynamic model was established to numerically study the relationship of HAB and environmental conditions. The numerical experiments showed that the growth of diatom, the dominant HAB specie, was mainly restricted by phosphate and silicate. If the concentrations of phosphate and silicate reach 17–25 µg/L and 300–375 µg/L respectively, the water is in a state of eutrophication. When phosphate and silicate up to 26–32 µg/L and 350–500 µg/L respectively, HAB could be induced. The major regions of HAB occurrence are Jiaozhou Bay mouth, coastal bays, and coastal area from Maidao to Shilaoren. To avoid HAB occurrence, concentration of phosphate and silicate should not exceed 17–20 µg/L and 300 µg/L as a whole. Reasonable control of pollutant discharge is a key point to prevent water eutrophication and HAB occurrence. Key wordsHAB–numerical model–marine ecosystem dynamics–environmental condition

Article
Nonylphenol (NP) and bisphenol A (BPA) are endocrine disruptors causing harmful effects including feminization and carcinogenesis to various organisms, and consequently, their contamination in natural environment has received wide concerns. This study reports the distribution characteristics of NP and BPA in surface sediments and their deposition history based on a dated sediment core in the Changjiang River (Yangtze River) Estuary and its adjacent East China Sea. The contents of NP and BPA in surface sediments ranged from 1.56–35.8 and 0.72–13.2 ng/g (dry mass), respectively, with high values recorded in the two mud zones, the Changjiang River Estuarine Mud Zone and the Zhejiang Coastal Mud Zone. High values in the Zhejiang Coastal Mud Zone suggest the possibility of long distance transport of both contaminants through the Changjiang riverine plume. The contents were not correlated with the distance from the pollution source, indicating other factors including particle deposition rate and sediment grain size obviously affecting the distribution pattern. NP was also detected in a sediment core at layers deposited from the year of 1971 to 2001 with contents of up to 20.9 ng/g (dry mass). The deposition fluxes of NP varied from 0.68 to 17.9 ng/(cm2·a) with peaks and valleys reflecting the traces of economic development history in China during the previous three decades. BPA was detected at sediment layers deposited from 1973 to 2001 with contents of up to 3.66 ng/g. The fluxes of BPA varied from 0.62 to 3.13 ng/(cm2·a) showing a similar pattern as NP. The contents of NP and BPA also indicated potential risks on benthic organisms in the study area. Key wordsnonylphenol–bisphenol A–endocrine disruptor–deposition flux–the Changjiang River (Yangtze River) Estuary

Article
Based on the simulation of a marine ecosystem dynamical model in the Bohai Sea, the Yellow Sea and the East China Sea, chlorophyll data are assimilated to study the spatially varying control parameters (CPs) by using the adjoint method. In this study, the CPs at some grid points are selected as the independent CPs, while the CPs at other grid points can be obtained through linear interpolation with the independent CPs. The independent CPs are uniformly selected from each 30′× 30′ area, and we confirm that the optimal influence radius is 1.2° by a twin experiment. In the following experiments, when only the maximum growth rate of phytoplankton (V m ) is estimated by two given types of spatially varying CPs, the mean relative errors of V m are 1.22% and 0.94% while the decrease rates of the mean error of chlorophyll in the surface are 94.6% and 95.8%, respectively. When the other four CPs are estimated respectively, the results are also satisfactory, which indicates that the adjoint method has a strong ability of optimizing the prescribed CP with spatial variations. However, when all these five most important CPs are estimated simultaneously, the collocation of the changing trend of each parameter influences the estimation results remarkably. Only when the collocation of the changing trend of each parameter is consistent with the ecological mechanisms which influence the growth of the phytoplankton in marine ecosystem, could the five most important CPs be estimated more accurately. Key wordsmarine dynamical ecosystem–adjoint method–influence radius–spatially varying parameters

Article
An algal bloom is defined as a relatively rapid increase in the biomass of phytoplankton in an aquatic system. During 30 March to 24 April 2007, a cruise was conducted in the central Southern Huanghai Sea to investigate the spring bloom processes. The spatial and temporal variations of phytoplankton are discussed based on the in-situ observations and simultaneous remote sensing data. The explosive algal blooming varied quickly in temporal and spatial scales, due to the highly patchy distribution. Data obtained at the 2 anchor stations (BM1 and BM2) were analyzed in the present study. Horizontal advection is speculated to be responsible for the abrupt decrease in the concentration of chlorophyll-a at stations BM1 and BM2. At station BM2, the intermediate high chlorophyll-a concentration, coinciding with the low temperature, was found to be advected from the inshore colder water mass located to the east of the site. Key wordschlorophyll-a–algal bloom–horizontal advection–remote sensing–Southern Huanghai Sea

Article
The study aims to reveal phylogenetic and evolutionary relationship between aerobic anoxygenic phototrophic bacteria (AAnPB) and their relatives, anaerobic anoxygenic phototrophic bacteria (AnAnPB) and nonphototrophic bacteria (NPB, which had high homology of 16S rDNA gene with AAnPB and fell into the same genus), and validate reliability and usefulness of farnesyl pyrophosphate synthase (FPPS) gene for the phylogenetic determination. FPPS genes with our modified primers and 16S rDNA genes with general primers, were amplified and sequenced or retrieved from GenBank database. In contrast to 16S rDNA gene phylogenetic tree, AAnPB were grouped into two clusters and one branch alone with no intermingling with NPB and AnAnPB in the tree constructed on FPPS. One branch of AAnPB, in both trees, was located closer to outgroup species than AnAnPB, which implicated that some AAnPB would be diverged earlier in FPPS evolutionary history than AnAnPB and NPB. Some AAnPB and NPB were closer located in both trees and this suggested that they were the closer relatives than AnAnPB. Combination codon usage in FPPS with phylogenetic analysis, the results indicates that FPPS gene and 16S rRNA gene have similar evolutionary pattern but the former seems to be more reliable and useful in determining the phylogenic and evolutionary relationship between AAnPB and their relatives. This is the first attempt to use a molecular marker beside 16S rRNA gene for studying the phylogeny of AAnPB, and the study may also be helpful in understanding the evolutionary relationship among phototrophic microbes and the trends of photosynthetic genes transfer. Key wordsaerobic anoxygenic phototrophic bacteria–farnesyl pyrophosphate synthase–phylogeny–anaerobic anoxygenic phototrophic bacteria–nonphototrophic bacteria

Article
A total of 117 agar-decomposing cultures were isolated from coastal seawater around Qingdao, China. The phenotypic and agarolytic features of an agarolytic isolate, QM38, were investigated. The strain was gram negative, strictly aerobic, curved rod and polar flagellum. On the basis of several phenotypic characters, biochemical and morphological characters and phylogenetic analysis of the gene coding for the 16S rRNA, the strain was identified as Agarivorans albus strain QM38. This strain can liquefy the agar on the solid agar plate. An excellular agarase activity was determined in liquid culture. The enzyme exhibited maximal activity at 40 °C, pH 7.6. Its activity was greatly affected by different concentrations of agarose. The highest activity 32 U/ml was achieved in the culture supernatant. The hydrolytic product was analyzed by fluorophore-assisted carbohydrate electrophoresis (FACE). After complete hydrolysis of agarose, a series of agaro-oligosaccharides were produced. The main products of the enzymes were oligosaccharides in the degree of polymerization (DP) of 2, 4, 6 and 8. Three genes agaD01, agaD02 and agaD03, encoding β-agarases, had been cloned from genomic DNA of Agarivorans albus strain QM38. The open reading frame of agaD01, consisted of 2 988 bp, and shared 95.5%–98.9% identity to the β-agarase genes of some strains of Vibrio and Agarivorans. Gene agaD02 comprised 2 868 bp and encoded a 955- amino-acid protein. It showed 97.4% and 98.7% identity to the β-agarase genes of strain Vibrio sp. PO-303 and strain Vibrio sp. JT0107, respectively. Only partial sequence of agaD03 gene has been cloned. It showed 96.5% identity to β-agarase gene (agaB) of Pseudoalteromonas sp. CY24, and shared 96.8% identity to β-agarase-c gene of Vibrio sp. PO-303. Key wordsmarine bacteria–isolation and characterization–agarase–gene cloning– Agarivorans albus

Article
It is well known that marine sponges harbor large numbers of bacteria, some of which have been proved to be sponge-specific. The diversity of bacteria in marine sponges distributed along the coast of South China Sea has been previously studied but that of bacteria in sponges inhabiting the open sea has been rarely investigated. In this report, the diversity of bacteria associated with the marine sponge Agelas robusta from a remote coral reef in the South China Sea was documented employing 16S rDNA library construction, amplified ribosomal DNA restriction analysis (ARDRA) and phylogenetic analysis. A total of 32 phylotypes were finally categorized in nine phyla including Cyanobacteria, Proteobacteria, Chloroflexi, Firmicutes, Actinobacteria, Acidobacteria, Planctomycetes, Bacteroidetes and Gemmatimonadetes. The dominant phylum was Proteobacteria whereas the dominant genus was Synechococcus in Cyanobacteria. Some spongespecific bacteria were also found in the bacteria population, but the proportion (5 OTUs/32 OTUs) was much lower than other sponges. This study reveals the phylogenetic diversity of bacteria in A. robusta and confirms the presence of some sponge-specific bacteria in the South China Sea. Understanding the diversity of sponge-associated bacteria in China assists to exploit the bacteria resources for biotechnology. Key wordsSouth China Sea– Agelas robusta –phylogenetic diversity–sponge-specific bacteria

Article
This paper proposes the retrieval method of ocean wave spectrum for airborne radar observations at small incidence angles, which is slightly modified from the method developed by Hauser. Firstly, it makes use of integration method to estimate total mean square slope instead of fitting method, which aims to reduce the affects of fluctuations superposed on normalized radar cross-section by integration. Secondly, for eliminating the noise spectrum contained in signal spectrum, the method considers the signal spectrum in certain look direction without any long wave components as the assumed noise spectrum, which would be subtracted from signal spectrum in any look direction for linear wave spectrum retrieval. Estimated ? from the integration method are lower than the one from fitting method and have a standard deviation of 0.004 between them approximately. The assumed noise spectrum energy almost has no big variations along with the wave number and is slightly lower to the high wave number part of signal spectrum in any look direction, which follows that the assumption makes sense. The retrieved directional spectra are compared with the buoy records in terms of peak wavelength, peak direction and the significant wave height. Comparisons show that the retrieved peak wavelength and significant wave height are slightly higher than the buoy records but don't differs significantly (error less than 10%). For peak direction, the swell waves in first case basically propagate in the wind direction 6 hours ago and the wind-generated waves in second case also propagate in the wind direction, but the 180? ambiguity remains. Results show that the modified method can carry out the retrieval of directional wave spectrum. © The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg 2011.

Article
China Marine Surveillance Force was equipped with modern aerial equipments for marine law-execute 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. Key wordsairborne remote sensing-water quality monitoring-multi-spectrum-hyper-spectrum

Article
Using the observations from ICOADS datasets and contemporaneous NCEP/NCAR reanalysis datasets during 1960–2002, the study classifies the airflows in favor of sea fog over the Huanghai (Yellow) Sea in boreal spring (April–May) with the method of trajectory analysis, and analyzes the changes of proportions of warm and cold sea fogs along different paths of airflow. According to the heat balance equation, we investigate the relationships between the marine meteorological conditions and the proportion of warm and cold sea fog along different airflow paths. The major results are summarized as follows. (1) Sea fogs over the Huanghai Sea in spring are not only warm fog but also cold fog. The proportion of warm fog only accounts for 44% in April, while increases as high as 57% in May. (2) Four primary airflow paths leading to spring sea fog are identified. They are originated from the northwest, east, southeast and southwest of the Huanghai Sea, respectively. The occurrence ratios of the warm sea fog along the east and southeast airflow paths are high of 55% and 70%, while these along the southwest and northwest airflow paths are merely 17.9% and 50%. (3) The key physical processes governing the warm/cold sea fog are heat advection transport, longwave radiation cooling at fog top, solar shortwave warming and latent heat flux between airsea interfaces. (4) The characteristics of sea fog along the four airflow paths relate closely to the conditions of water vapor advection, and the vertical distribution of relative humidity. Key wordsspring sea fog over the Huanghai Sea-airflow paths-water vapor flux-heat advection-vertical distribution of water vapor

Article
Harmful algal blooms (HABs) have been affecting negatively the shellfish and aquaculture industries around the world. Though a lot of efforts have been made to disclose the changes of environmental factors involved and their effects on the HABs events, the molecular mechanism of this process remains unclear. To address this problem, proliferating cell nuclear antigen gene (pcna) was isolated and characterized from Alexandrium catenella. It showed high homology to those of other dinoflagellates (89% and 91% homology to Pfiesteria piscicid and Pyrocystis lunula, respectively), and also 42%–43% homology to those of plant and animals. The expression level of pcna revealed by quantitative real time PCR was the lowest at the late lagging cell growth phase, increased to the highest at the late exponential phase, and then decreased at the stationary phase. Though the cell growth rate was also changing, no positive correlation between pcna expression level and cell growth rate was displayed throughout the whole cell growth stages (r 2=0.024 6). However, the pcna expression level had the similar trend with the change of cell growth rate throughout the whole growing process, e.g., from increasing at the earlier cell growth stage to decreasing at the following stages, though slightly lagging to the latter.

Article
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. Key wordsred tides- Alexandrium species- Moina mongolica Daday-toxic effect

Article
The authors have investigated the biochemical events by which marine algal virus infection induces cell cycle arrest. The key G2/M-phase regulatory proteins are analyzed by immunobloting in unicellular Emiliania huxleyi, suggesting that virus induced cell cycle arrest is related with virus’s effect on cyclins and cyclin dependent kinases. E. huxleyi virus (EhV) represses Cdc2/cyclinB complex activity by inhibiting the activity of Cdc2 kinase in a phosphorylation-related manner, blocking host cells G2/M checkpoint. Dephosphorylated / inactive Cdc25C combined with up-regulation of Wee1 expression at early infect period appears to be important mechanisms by which EhV represses Cdc2/cyclinB complex activity that is required for entry into M phase. This study has allowed us to confirm that algal virus infection leads to selective activation or inhibition of certain cell-cycle factors, which may play a significant role in establishing a more efficient environment for viral gene expression and DNA replication. Key wordsmarine algal virus–cell cycle regulators expression– Emiliania huxleyi

Article
Considering that the field is largely unexplored and its importance to aquaculture, outline of oomycetes and fungi parasiting on marine algae was provided in this paper, including 15 species of oomycetes, six species of chytrids, 31 Ascomycota species and one species of mitosporic fungi. In natrue, both the oomycetes and chytrids frequently occurred and induced prevalences of disease which could destroy the populations of host plants greatly. However, the parasites in Ascomycota on algae have never occurred as epidemics so far. Some issues relating to the field were discussed such as performing tests to satisfy Koch’s postulates, investigations of host specificity, interactions between host and parasite and the potential effects of environmental factors on occurrence of a disease, which are urgent in need of further investigations. Key wordsoomycetes–fungi–parasites–marine algae

Article
The excitation spectra of chlorophyll (Chl) fluorescence can be used to differentiate phytoplankton populations at phylum level in vivo and in situ within a few minutes. The investigated phytoplankton divisions (Dinophyta, Bacillariophyta, Chrysophyta, Cyanophyta, Cryptophyta, Chlorophyta) are each characterized by a specific composition of photosynthetic antenna pigments and, consequently, by a specific excitation spectrum of the Chl fluorescence. Norm excitation spectra (emission of 680 nm and excitation of 400–600 nm) of every division were obtained from several species per division by a F4500 fluorescence spectrophotometer. Fisher’s linear discriminant analysis of the norm spectra shows that the divisions could be discriminated. The discrimination method, established by multivariate linear regression and weighted least squares, was used to differentiate the phytoplankton samples cultured in the laboratory and samples collected from the Jiaozhao Bay at division level. The correctly discriminated samples were more than 94% for single algal species ones, more than 84% for simulatively mixed ones, more than 83% for real mixed ones and 100% for samples collected from the Jiaozhou Bay for the dominant species. The method for phytoplankton differentiation described here can be applied to routine checking by fluorescence spectrophotometer, and benefit the monitoring and supervision tasks related to phytoplankton populations in the marine environments. Key wordsfluorescence spectrum-discrimination-weighted least squares-phytoplankton

Article
The invasive red alga Grateloupia turuturu Yamada could turn Vibrio parahaemolyticus into nonculturable state in live algal culture. In order to elucidate the mechanism of such an effect, a series of culture experiments were performed in this investigation based on three hypothesized causes, namely bacterial attachment, production of reactive oxygen species (ROS) and the discharge of water soluble secondary metabolic compounds. The results reveal that attachment to the thallus surface of G. turuturu was the major reason for the decrease of V. parahaemolyticus in seawater. Further investigations show that V. parahaemolyticus attachment to the surface of algal thallus in live cultures of seaweeds was a common phenomenon. However, the disappearance of the culturability of V. parahaemolyticus occurred only on the thallus of G. turuturu over 72 h among all six algal species tested. Electron microscopic scanning shows that most of V. parahaemolyticus attached to G. turuturu changed from the initial normal bacilli to coccoid-shape after 72 h. The enclosure experiments by enclosing the algal thallus in tubes demonstrate that the nonculturability of V. parahaemolyticus in the water of live culture of G. turuturu occurred after the physical contact of the V. parahaemolyticus to the alga. The capacity of G. turuturu in affecting the culturability of V. parahaemolyticus was not influenced after inhibition of photosynthesis by treatment of 3′-(3,4-dichlorophenyl)-1′,1′-dimethyl urea (DCMU) at non-lethal levels. Production of reactive oxygen species after addition of live culture of bacteria was excluded by on-line analyzing the oxidation of dichlorohydrofluorescein (DCFH) to dichlorofluorescein (DCF) in the presence of peroxidase on a VersaFluor fluorometer. Key words Grateloupia turuturu –attachment– Vibrio parahaemolyticus –nonculturability–effective quantum yield

Article
An optimal interpolation assimilation model for satellite altimetry data is developed based on Princeton Ocean Model (POM), which is applied in a quasi-global domain, by the method of isotropic correlation between sea level anomaly (SLA) and sea temperature anomaly. The performance of this assimilation model is validated by the modeled results of SLA and the current patterns. Comparisons between modeling and satellite data show that both the magnitudes and distribution patterns of the simulated SLA are improved by assimilation. The most significant improvement is that meso-scale systems, e.g., eddies, are well reconstructed. The evolution of an eddy located in the northwest Pacific Ocean is traced by using the assimilation model. Model results show that during three months the eddy migrated southwestward for about 6 degrees before merging into the Kuroshio. The three dimensional structure of this eddy on 12 August 2001 is further analyzed. The strength of this warm, cyclonic eddy decreases with the increase of depth. The eddy shows different horizontal patterns at different layers, and the SLA and temperature fields agree with each other well. This study suggests that this kind of data assimilation is economic and reliable for eddy reconstruction, and can be used as a promising technique in further studies of ocean eddies as well as other fine circulation structures. Key wordsdata assimilation-eddy-numerical model-optimal interpolation-POM

Article
Sampling errors of the global mean sea level derived from TOPEX/Poseidon (T/P) altimetry are explored using $$3\frac{1} {4}$$ a of eddy-resolving numerical model outputs for sea level. By definition, the sampling errors would not exist if data were available everywhere at all times. Four problems with increasing and progressively added complexities are examined to understand the causes of the sampling errors. The first problem (P1) explores the error incurred because T/P with turning latitudes near 66° latitudes does not cover the entire globe. The second problem (P2) examines, in addition, the spatial sampling issue because samples are only available along T/P ground tracks. The third problem (P3) adds the additional complexity that sea level at any along track location is sampled only once every 10 d versus every 3 d for the model (i.e., the temporal sampling issue). The fourth problem (P4) incorporates the full complexity with the addition of real T/P data outages. The numerical model (Los Alamos POP model Run 11) conserves the total water volume, thus generating no global mean sea level variation. Yet when the model sea level is sampled in the four problems (with P4 using the real T/P sampling), variations occur as manifestations of the sampling errors. The results show root-mean-squares (rms) sampling errors for P1 of 0.67 (0.75) mm for 10 d (3 d) global mean sea level, 0.78 (0.86) mm for P2, 0.79 mm for P3, and 1.07 mm for P4, whereas the amplitudes of the sampling errors can be as large as 2.0 (2.7) mm for P1, 2.1 (2.7) mm for P2,2.2 mm for P3, and 2.5 mm for P4. The results clearly show the largest source of the sampling errors to be the lack of global coverage (i.e., P1), which the model has actually underestimated due to its own less-than-global coverage (between latitudes about 77° latitudes). We have extrapolated that a truly global model would show the rms sampling error to be 1.14 (1.28) mm for P1, thus implying a substantially larger sampling error for P4.

Article
Dark respiration (non-photorespiratory mitochondrial respiration), which occurs both in the light and in darkness, is vital for growth and survival of algae and plays a critical role in modulating the carbon balance of them. In the present study, we have investigated dark respiration in the light (R L) and in darkness (R D) in three marine macroalgal species, Hizikia fusiformis (phaeophyta), Gracilaria lemaneiformis (Rhodophyta) and Ulva lactuca (Chlorophyta), cultured at 20 °C using aeration with two CO2 conditions: current ambient (CO2 concentration about 380 µl/L) and elevated CO2 (approximately 720 µl/L) air. R L was estimated by using the Kok method, whereas R D was determined as the rate of O2 influx at zero light. The results showed that both R L and R D were unchanged for the elevated CO2-grown algae relative to ambient CO2 concentration for all the algal species tested. However, R L was significantly lower than R D across all the algal species and growth CO2 treatments, demonstrating that daytime respiration was partly depressed by the light. The percentage of inhibition of respiration by light was similar between ambient and elevated CO2-grown algae. The ratio of respiration to photosynthesis, which tended to decrease when estimated using R L instead of R D, was not altered for the elevated relative to ambient CO2 concentration. The results suggest that R L, rather than R D, is a more accurate estimate of nonphotorespiratory carbon loss in marine macroalgae during the daytime. It would not be anticipated that elevated atmospheric CO2 would exert a substantial influence on respiratory flux either in the light or in darkness in these particular marine macroalgal species. Key wordsmarine macroalgae–respiration–CO2 –carbon balance

Article
The spatial distribution of ammonia-oxidizing Betaproteobacteria (βAOB) was investigated by FISH (fluorescence in situ hybridization) and DGGE (denaturing gradient gel electrophoresis) techniques in the sediment off the Changjiang River Estuary. Sediment samples were collected from eight stations in June before the formation of hypoxia zone in 2006. The abundance of βAOB ranged from 1.87×105 to 3.53×105 cells/g of sediment. βAOB abundance did not present a negative correlation with salinity, whereas salinity was implicated as the primary factor affecting nitrification rates. The DGGE profiles of PCR-amplified amoA gene fragments revealed that the βAOB community structure of sample S2 separated from other samples at the level of 40% similarity. The variations in composition of βAOB were significantly correlated with the salinity, temperature, absorption ability of sediments and TOC. The statistical analysis indicates that the βAOB abundance was a main factor to influence nitrification rates with an influence ratio of 87.7% at the level of 40% biodiversity similarity. Considering the good correlation between βAOB abundance and nitrification estimates, the abundance and diversity of βAOB community could be expected as an indirect index of nitrification activity at the study sea area in summer. Key wordsammonia-oxidizing Betaproteobacteria (βAOB)–diversity–abundance–nitrification–surface sediment–Changjiang River Estuary (CRE)

Article
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. Key words Vibrio vulnificus -LAMP-virulence-correlated gene-seawater-culture-free-VBNC

Article
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. Key wordstime-dependent-mild-slope equation-nonlinear amplitude dispersion-steep or rapidly varying topography-bottom friction-wave breaking

Article
The system with one floating rectangular body on the free surface and one submerged rectangular body has been applied to a wave energy conversion device in water of finite depth. The radiation problem by this device on a plane incident wave is solved by the use of an eigenfunction expansion method, and a new analytical expression for the radiation velocity potential is obtained. The wave excitation force is calculated via the known incident wave potential and the radiation potential with a theorem of Haskind employed. To verify the correctness of this method, an example is computed respectively through the bound element method and analytical method. Results show that two numerical methods. are in good agreement, which shows that the present method is applicable. In addition, the trends of hydrodynamic coefficients and wave force are analyzed under different conditions by use of the present analytical method. Key wordswave energy device-hydrodynamic coefficients-wave force-analytical method

Article
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. Key words Anthopleura midori -Bacterial diversity-16S rRNA gene-Phylogeny-Identification

Article
A data assimilation scheme used in the updated Ocean three-dimensional Variational Assimilation System (OVALS), OVALS2, is described. Based on a recursive filter (RF) to estimate the background error covariance (BEC) over a predetermined scale, this new analysis system can be implemented with anisotropic and isotropic BECs. Similarities and differences of these two BEC schemes are briefly discussed and their impacts on the model simulation are also investigated. An idealized experiment demonstrates the ability of the updated analysis system to construct different BECs. Furthermore, a set of three years experiments is implemented by assimilating expendable bathythermograph (XBT) and ARGO data into a Tropical Pacific circulation model. The TAO and WOA01 data are used to validate the assimilation results. The results show that the model simulations are substantially improved by OVALS2. The inter-comparison of isotropic and anisotropic BEC shows that the corresponding temperature and salinity produced by the anisotropic BEC are almost as good as those obtained by the isotropic one. Moreover, the result of anisotropic RF is slightly closer to WOA01 and TAO than that of isotropic RF in some special area (e.g. the cold tongue area in the Tropic Pacific). Key wordsrecursive filter–anisotropic–isotropic–background error covariance

Article
Teleconnection between El Nino/La Nina-Southern Oscillation (ENSO) phenomenon and anomalous Antarctic sea-ice variation has been studied extensively. In this study, impacts of sea surface temperature in the Indian Ocean on Antarctic sea-ice change were investigated during Janaury 1979 and October 2009. Based on previous research results, sea areas in the western Indian Ocean (WIO; 50°-70°E, 10°-20°S) are selected for the resreach. All variables showed 1–10 year interannual timescales by Fast Founer Tranaform (FFT) transformation. Results show that i) strong WIO signals emerged in the anomalous changes of Antarctic sea-ice concentration; ii) significant positive correlations occurred around the Antarctic Peninsula, Ross Sea and its northwest peripheral sea region iii) negative correlation occurred in the Indian Ocean section of the Southern Ocean, Amundsen Seas, and the sea area over northern Ross Sea; and iv) the atmospheric anomalies associated with the WIO including wind, meridional heat flux, and surface air temperature over southern high latitudes were the possible factors for the teleconnection. Key wordsAntarctic sea-ice–western Indian Ocean–sea surface temperature

Article
The investigation on sea-ice biology in combination with physics, chemistry and ecology was carried out in the northwestern Weddell Sea, Antarctica, during the cruise ANT/XX III-7 on board POLARSTERN in the austral winter (August–October) in 2006. The distribution of chlorophyll a was measured and related to sea ice texture. The mean concentrations of chlorophyll a in the sea ice varied considerably with ice texture. The concentration of chlorophyll a per core ranged from 2.10–84.40 µg/dm3 with a mean of 16.56 µg/dm3. And the value of R (chlorophyll a / gross chlorophyll) ranged from 0.79–0.83. These high winter chlorophyll values indicate that primary production is considerable and confirms that there is significant primary production in Antarctic sea ice during winter. Thus this constitutes a major proportion of southern ocean primary production and carbon flux before the sea ice retreats. Key wordsphysical structure-chlorophyll a-Antarctica-winter sea-ice

Article
Simple sequence repeat (SSR) markers were obtained for the large yellow croaker Pseudosciaena crocea using 1 205 expressed sequences tags (ESTs) from the NCBI database. Primers for 48 ESTSSR loci were designed and screened with 30 P.crocea specimens captured from Guanjingyang sea area in Fujian Province of China. Sixteen of the loci were polymorphic, which were amplified with 3 to 11 alleles per locus and the mean of 6.13. The observed and expected heterozygosity per locus ranged from 0.091 to 0.844 (mean 0.544) and from 0.118 to 0.892 (mean 0.644), respectively. Polymorphic information content (PIC) ranged from 0.115 to 0.866 (mean 0.593). The results for cross-species amplification of the 16 large yellow croaker EST-SSRs on P. polyactis, C. niveatus, C. lucidus, A. argentatus and J. belengeri revealed that 14, 12, 11, 7 and 6 loci were successfully amplified with 1 to 10 alleles with an average of 4.5 per locus, respectively, which are suitable for population genetics studies of these species and useful for phylogenetic relationship analysis among these species. Overall, this study provides a set of type I markers for population genetics studies and genome mapping for large yellow croaker and its closely related species. Key words Pseudosciaena crocea –EST-SSRs–genetic diversity–cross-species amplification

Article
Based on the published data of structure geology, geochronology, petrology and isotope geochemistry, the authors of this paper have conducted studies on the tectonic evolution history of Japan arc system and Kyushu-Palau ridge (KPR). The studies show that the initial Japan arc system was resulted from the subduction of ancient Pacific plate beneath Eurasian Plate in Permian. It was part of an Andean-type continental volcanic arc which occurred in the offshore in the east of Asian during late Mesozoic era. The formation of tertiary back-arc basin (Japan Sea) resulted in the fundamental tectonic framework of the present arc system. Since Quaternary the system has been lying at E-W compression tectonic setting due to the eastward subduction of Amur Plate. It is expected that Japan arc system will be juxtaposed with Asian continent, which is similar to the present Taiwan arc system. The origin of Philippine Sea Plate (PSP) is still in debate. Some studies argued that it is a trapped oceanic crust segment, while the others insisted that it is a back-arc basin accompanied with ancient IBM arc. However, it is all agreed that the tectonic evolution of PSP started since 50 Ma, i.e., PSP has drifted from the site around equator at 50 Ma to the present site, and the subduction of PSP along Nankai trough-Ryukyu Trench beneath the Japan arc system during 6–2 Ma led to the formation of the present Ryukyu arc system. Of the PSP, the KPR has been found with the oldest rocks formed at 38 Ma. Combining with its geochemical characteristics of oceanic arc tholeiite, it is suggested that KPR is an intraoceanic volcanic arc, more specifically, a relic arc (i.e., rear arc of the ancient IBM) after rifting of ancient IBM. In addition, Amami-Daito province is of arc tectonic affinity, but has been affected by mantle plume. Therefore, based on their respective tectonic evolution history and geochemical characteristics of rock samples, it is inferred that there is no genetic relationship between Japan arc system and KPR. It is noted that rocks reflecting continental crust basement feature have been collected on the northern tip of KPR, which may be related to the process of KPR accreting on Japan arc, but the arc-continent accretion process are still at initial stage of modern continental crust accretion model. However, due to the scarcity of data of the northern tip of KPR, crustal structure of this location and its adjacent Nankai trough need to be further constrained by geophysical studies in the future. Key wordsJapan arc system–Kyushu-Palau ridge (KPR)–Philippine sea plate (PSP)–Tectonic evolution–geochronology–geochemistry

Article
By using the Arctic runoff data from R-ArcticNET V4.0 and ArcticRIMS, trends of four major rivers flowing into the Arctic Ocean, whose climate factor plays an important role in determining the variability of the Arctic runoff, are investigated. The results show that for the past 30 years, the trend of the Arctic runoff is seasonally dependent. There is a significant trend in spring and winter and a significant decreasing trend in summer, leading to the reduced seasonal cycle. In spring, surface air temperature is the dominant factor influencing the four rivers. In summer, precipitation is the most important factor for Lena and Mackenzie, while snow cover is the most important factor for Yenisei and Ob. For Mackenzie, atmospheric circulation does play an important role for all the seasons, which is not the case for the Eurasian rivers. The authors further discuss the relationships between the Arctic runoff and sea ice. Significant negative correlation is found at the mouth of the rivers into the Arctic Ocean in spring, while significant positive correlation is observed just at the north of the mouths of the rivers into the Arctic in summer. In addition, each river has different relationship with sea ice in the eastern Greenland Sea. Key wordsArctic runoff–multiple linear regressions–sea ice

Article
Waters along China coast are very turbid with high concentrations of suspended sediment nearly all the time, especially at the Hangzhou Bay, the Changjiang (Yangtze) River Estuary and the shoal along Jiangsu Province. In these turbid and optically complex waters, the standard MODIS ocean color products tend to have invalid values. Because the water-leaving radiances in the near-infrared (NIR) are significant resulting from the strong scattering of suspended particles, the standard MODIS atmospheric correction algorithm often gets no results or produces significant errors. And because of the complex water optical properties, the OC3 model used in the standard MODIS data processing tends to get extremely high chlorophyll-a (Chl-a) concentrations. In this paper, we present an atmospheric correction approach using MODIS short wave infrared (SWIR) bands based on the fact that water-leaving radiances are negligible in the SWIR region because of the extreme strong absorption of water even in turbid waters. A regional Chl-a concentration estimation model is also constructed for MODIS from in situ data. These algorithms are applied to MODIS Aqua data processing in the China coastal regions. In situ data collected in the Yellow Sea and the East China Sea in spring and autumn, 2003 are used to validate the performance. Reasonably good results have been obtained. It is noted that water-leaving reflectance in the NIR bands are significant in waters along the China coast with high sediment loadings. The satellite derived and in-situ reflectance spectra can match in the turbid waters along China coast, and there is relatively good linear relationship between satellite derived and in-situ reflectance. The RMSE value of Rrs(λ) is 0.0031 sr−1 for all the nine ocean color bands (412 to 869 nm). The satellite-derived Chl-a value is in the reasonable range and the root mean square percentage difference is 46.1%.

Article
The formation mechanism of the large hydrothermal sulfide deposit is a complex geological process involving many controlling factors. Mixing between hydrothermal fluid and seawater plays a key role in this process. The results of the Ocean Drilling Program (ODP) indicate that mixing of the evolved seawater and hydrothermal fluid, which is wildly developed within the Trans-Atlantic Geo-Traverse (TAG) hydrothermal deposit, governs the internal structure and chemical compositions of the deposit to great extent. Taking the TAG field for example, the mixing processes of hydrothermal fluid with the seawater heated to different extent are calculated, so as to discuss the impact of hydrothermal fluid/seawater mixing on the formation process of the sulfide deposit. The results indicate that: (1) mixing between the heated seawater and hydrothermal fluid derived from the deep deposit is largely responsible for the wild precipitation of anhydrite within the TAG hydrothermal deposit; (2) 330–310°C is a special temperature range in the mixing process; (3) the mixing and hydrothermal processes in different zones of the TAG hydrothermal deposit (TAG-1, TAG-2 and TAG-5, etc.) have been discussed based on the simulated results. Key wordshydrothermal sulfide deposit-mixing process-TAG hydrothermal field-numerical simulation

Article
In the satellite synthetic aperture radar (SAR) images of the Bohai Sea and Huanghai Sea, the authors observe sea surface imprints of wave-like patterns with an average wavelength of 3.8 km. Comparing SAR observations with sea surface wind fields and surface weather maps, the authors find that the occurrence of the wave-like phenomena is associated with the passing of atmospheric front. The authors define the waves as atmospheric frontal gravity waves. The dynamical parameters of the wave packets are derived from statistics of 9 satellite SAR images obtained from 2002 to 2008. A two-dimensional linear physical wave model is used to analyze the generation mechanism of the waves. The atmospheric frontal wave induced wind variation across the frontal wave packet is compared with wind retrievals from the SAR images. The CMOD-5 (C-band scatterometer ocean geophysical model function) is used for SAR wind retrievals VV (transmitted vertical and received vertical) for ENVISAT and HH (transmitted horizontally and received horizontally) for RADARSAT-1. A reasonable agreement between the analytical solution and the SAR observation is reached. This new SAR frontal wave observation adds to the school of SAR observations of sea surface imprints of AGWs including island lee waves, coastal lee waves, and upstream Atmospheric Gravity Waves (AGW). Key wordsAtmospheric gravity waves–atmospheric front–generation mechanism–synthetic aperture radar

Article
By using the TRMM and QuikSCAT datathe characteristics of the 2–8 day high frequency atmospheric variability over the South China Sea are studied in this paper. It’s found that: (1) the 2–8 day high frequency signals are significant not only during the periods of the South China Sea Summer Monsoon (SCSSM), but also after the retreat of the SCSSM. It reaches its peak around July to August; (2) the 2–8 day high frequency signals exhibit strong intermittent features; (3) During El Nino years, the 2–8 day high frequency signals are active only in the periods of the SCSSM. During La Nina years, the 2–8 day high frequency signals are obviously not only in periods of the SCSSM, but also after the retreat of the SCSSM. During the SCSSM periods, the 2–8 day high frequency signals in El Nino years are much stronger than that in La Nina years; (4) During spring to early summer, most of 2–8 day signals propagate southward and eastward, during midsummer to autumn, however, most of 2–8-day signals propagate northward and westward; (5) The 2–8 day northward and westward propagation signals is probably related to the activities of high-frequency vortex over the SCS. Key wordshigh-frequency atmospheric variability–South China Sea–TRMM–QuikSCAT

Article
16S rDNA sequencing results from this study and literatures demonstrate that sediment bacteria in the South China Sea (SCS) were very diverse, which contained 22 of the 24 phyla of bacteria investigated from marine sediment, however, it was very imbalance among stations. So bacterial diversity from 15 samples which covered a wide range of sediment types from 20 to 3 888 m in depth was studied in DGGE (denature gradient gel electrophoresis) in this paper. The DGGE results indicate that both sediment bacterial diversity and diversity difference among stations were significant. Thirty representative and differential fingerprints among samples were recovered and sequenced, phylogenetic analysis indicates that they may belong to Proteobacteria (α-, β-, γ-, δ-, ɛ-), Planctomycetes, Firmicutes, Chloroflexi, Acidobacteria, Actinobacteria, Nitrospirae, Gemmatimonadetes, candidate division WS3 and so on, of which, Gemmatimonadetes and candidate division WS3 bacteria were first detected in SCS sediment. This study also shows that bacterial diversity analysis based on DGGE was more potential than traditional 16S rDNA clone library in multiple sample analysis. Key wordsbacterial diversity-DGGE-marine sediment-South China Sea

Top-cited authors
• First Institute of Oceanography
• University of Maryland, College Park
• Second Institute of Oceanography MNR
• First Institute of Oceanography
• China University of Geosciences