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Simulation of potential tsunami hazards in the South China Sea
PAN Wen-liang,WANG Sheng-an,CAI Shu-qun
Journal of Tropical Oceanography    2009, 28 (6): 7-14.   DOI: 10.11978/j.issn.1009-5470.2009.06.007
Abstract2522)      PDF(pc) (4945KB)(1849)       Save

Based on comprehensive consideration of topography, geological structureseismological features and historical records, the authors analyze the hazardous tsunamigenic zones in the South China Sea and discuss the possibility of potential tsunami hazards in the region. A tsunami induced by a hypothetical earthquake in the Manila Trench is simulated using a nested 3-layer grid system with high resolution. Each grid area in the grid system can be configured with its own type of coordinate system depending on its coverage, simulation parameters as well as the governing equations in terms of the characteristics at different stages of tsunami propagation. This flexible, nested grid setup allows for a balance between computational accuracy and efficiency. The simulation resultssuch as the calculated travel time map, maximum surface elevation and water height series at four virtual gauges, indicate that the tsunami hazards could happen on the coasts off South China. Further research is necessary to determine the need for a monitoring system of tsunami in the region.

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Cited: Baidu(22) CSCD(10)
Relationship between the Western Pacific Subtropical High and sea-surface temperature anomaly
FAN Lei,LIU Qin-yu
Journal of Tropical Oceanography    2009, 28 (5): 83-88.   DOI: 10.11978/j.issn.1009-5470.2009.05.083
Abstract2510)      PDF(pc) (6368KB)(2141)       Save

The authors study the relationship between the Western Pacific Subtropical High (WPSH) and sea-surface temperature (SST) anomaly in each selected key area based on lag correlation analysis. The lag correlation indicates that the eastern Pacific SST in winter correlates with the WPSH anomaly two or three months later to the highest degree; the SST in the tropical Indian Ocean and the WPSH anomaly in the corresponding period significantly correlates with each other in winter; and the SST in the western Pacific in winter and spring negatively correlates to the WPSH anomaly in the corresponding period. In addition, the SST in the northern Pacific in winter and spring negatively correlates with the WPSH anomaly one to two months earlier. The largest positive correlation between the Atlantic Warm Pool and the WPSH anomaly in the corresponding period occurs in June. Regarding to the southern Pacific, the WPSH anomaly in winter negatively correlates with the SST anomaly from last autumn to next spring. To sum up, in winter and spring, SST anomaly is almost fully responsible to the annual variation of the WPSH anomaly, but in summer and autumn, the influence of SST on the WPSH is constrained to a small scale.

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Cited: Baidu(8) CSCD(4)
Environmental pollution in the Pearl River Estuary: a review
HUANG Xiao-ping,TIAN Lei,PENG Bo,ZHANG Da-wen
Journal of Tropical Oceanography    2010, 29 (1): 1-7.   DOI: 10.11978/j.issn.1009-5470.2010.01.001
Abstract2484)      PDF(pc) (339KB)(3422)       Save

Environmental pollution is serious in the Pearl River Estuary due to human activities and an increasing attention has been paid to the pollution in this region. This paper mainly reviews the eutrophication characteristics and the pollution patterns of persistent toxic substances (PTS, including heavy metals and persistent organic pollutants—POPs) in the water. Results in-dicate that the excessive input of nitrogen and phosphate has led to the high eutrophication in the water. Eutrophication plays an important role in triggering red tides. The coupling effect of the water stratification and eutrophication leads to the seasonal hypoxia in certain areas of the estuary. PTS mainly accumulate in sediment and organisms. The records of pollutants in sedi-ment cores reflect that pollutant accumulation in sediments is closely related to the rapid economical development of the Pearl River Delta in the past three decades. Finally, the critical issues of research are put forward on the environmental pollution of this area in the future, which include biotransformation of pollutants in tissues and bioaccumlation in food chain, the combined pollution of various pollutants in eutrophic water, mechanisms of microbial biodegradation of pollutants, pollution control strategy, among others.

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Cited: Baidu(55) CSCD(18)
An improved, SSH-based method to automatically identify mesoscale eddies in the ocean
WANG Xin, DU Yun-yan, ZHOU Cheng-hu, FAN Xing, YI Jia-wei
Journal of Tropical Oceanography    2013, 32 (2): 15-23.   DOI: 10.11978/j.issn.1009-5470.2013.02.002
Abstract2386)      PDF(pc) (1543KB)(1896)       Save

Mesoscale eddies are an important component of oceanic features. How to automatically identify these mesoscale eddies from available data has become an important research topic. Through careful examination of existing methods, we propose an improved, SSH-based automatic identification method. Using the inclusion relation of enclosed SSH contours, the mesoscale eddy boundary and core(s) can be automatically identified. The time evolution of eddies can be examined by a threshold search algorithm and a tracking algorithm based on similarity. Sea-surface height (SSH) data from Naval Research Laboratory Layered Ocean Model (NLOM) and sea-level anomaly (SLA) data from altimeter are used in the many experiments, in which different automatic identification methods are compared. Our results indicate that the improved method is able to extract the mesoscale eddy boundary more precisely, retaining the multiple-core structure. In combination with the tracking algorithm, this method can capture complete mesoscale eddy processes. It can thus provide reliable information for further study of reconstructing eddy dynamics, merging, splitting, and evolution of a multi-core structure.

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Cited: CSCD(6)
Assessment of the Pearl River Estuary pollution by water comprehensive pollution index and biodiversity index
ZHANG Jing-ping,HUANG Xiao-ping,JIANG Zhi-Jian,HUANG Dao-jian,HUANG Liang-min
Journal of Tropical Oceanography    2010, 29 (1): 69-76.   DOI: 10.11978/j.issn.1009-5470.2010.01.069
Abstract2188)      PDF(pc) (1159KB)(3555)       Save

Two cruises were carried out to investigate the water quality and ecological status in the Pearl River Estuary in July 2006 and March 2007. Water comprehensive pollution index and biodiversity index (including phytoplankton, zooplankton and benthos) were used to assess the pollution status. In addition, rationality of the assessment by using the biodiversity index was also discussed. The results indicated that the pollution degrees of the Pearl River Estuary were between moderate to severe. Water comprehensive pollution index showed that it was at a severely polluted status both in wet and dry seasons. Biodiversity index led to different results, which varied from lightly-moderate pollution to severe pollution. Among the three biodiversity indices, we considered that zooplankton diversity index was more congruent than the other two indices in pollution status assessment. However, the evaluation criteria should be verified and modified in future study. It was concluded that assessment for the environment quality and ecological status by using different biodiversity indices may come to a varied result, and a simple conclusion could not be hastily educed but should be associated with physicochemical factors.

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Cited: Baidu(47) CSCD(31)
Effects of NaHSO3 on the growth and contents of photosynthetic pigments in Dunaliella salina
CHENG Jian-feng,HU Fen-hong,SHEN Yun-gang
Journal of Tropical Oceanography    2010, 29 (3): 65-70.   DOI: 10.11978/j.issn.1009-5470.2010.03.065
Abstract2166)      PDF(pc) (326KB)(3975)       Save

Bisulfite (NaHSO3) is a substance to accelerate plant cyclic photophosphorylation that can be used safely and environmentally friendly. In order to optimize the nutrients formula, decrease the production cost and improve the biomass and pigment accumulation of Dunaliella salina, the authors investigated the effects of different concentrations (0.00?0.40mM•L-1) of NaHSO3 on the biomass and photosynthetic pigment contents. The results showed that NaHSO3 could significantly improve the growth, contents of chlorophyll (Chl) a, Chl b, Chl (a+b), carotenoid (Car) and ratio of Chl to Car. The effects firstly increased and then decreased with the increase of concentration. Accelerating effects under low concentrations (<0.10mM•L-1) were better than those under high concentrations (0.10?0.40mM•L-1), and the maximum accelerating effects were reaches at 0.07mM•L-1. NaHSO3 could increase Chl b content more than Chl a content, which caused the reduction of Chl a content relative to Chl b content; the effects firstly decreased and then increased with the increase of concentration, reducing effects under low concentrations (<0.1mM•L-1) were better than those under high concentrations (0.10?0.40mM•L-1), and the minimum reducing effect was achieved at 0.07mM•L-1. The correlations of biomass (Y) to contents of photosynthetic pigments and between contents of photosynthetic pigments were significant or markedly significant, with the highest correlation of Chl b (XChl.b) to biomass (Y=0.284XChl.b-0.883 (R2=0.994**)) and the next of Chl to biomass (Y=0.100XChl-2.022 (R2=0.993**)), which provided an indirect index to measure the growth of Dunaliella salina in every moment.

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An ecological study on fouling in the waters off the Bailong Peninsula in the Beibu Gulf
LI Heng-xiang,YAN Yan,HE Wei-hong,ZOU Xiao-li
Journal of Tropical Oceanography    2010, 29 (3): 108-113.   DOI: 10.11978/j.issn.1009-5470.2010.03.108
Abstract2152)      PDF(pc) (288KB)(4305)       Save

An annual panel test on fouling organisms was carried out in the waters off the Bailong Peninsula in the Beibu Gulf from March 2006 to February 2007. The fouling organisms from the wharf and the cultured cages during the same time were also investigated. The biofouling in this area reflected distinct characteristics of subtropical harbors. A total of 82 fouling organism species were recorded, among which Balanus reticulates, Dexiosprira foraminosus, Spirorbis papillatus, Bugula neritina, Membranipora grandicella, Styela canopus, Electra tenella, Perna viridis and Dendostrea crenulifera were dominant species. Bioattachment occurred throughout the year, but the main period of settlement extended from May to October of 2006. The mean biomass of fouling organisms on the monthly, seasonal, and annual test panels were 200.54, 2 550.37 and        15 121.67g•m?2, respectively, in the waters off the Bailong Peninsula, which were lower than those in the waters of the Daya Bay and Zhanjiang Harbor, but higher than those in the waters of the Qinglan Harbor and off the Weizhou Island. The attachments of fouling were greatly different in each tidal zone of the Bailong Wharf, with the dominant species Littorina scabra and Nodilittorina radiate on high tidal zone, Ostrea glomerata, Saccostrea echinata, Saccostrea cucullata and Tetreclita squamosa on middle tidal zone, and algae on low tidal zone. Different suggestions on biocontrol are given in the present study for protecting the artificial structures, mariculture, and estuarine ecology in the Bailong waters.

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Cited: Baidu(12) CSCD(9)
The impaction of typhoon on seafloor ambient noise by analyzing the OBS recording data
AO Wei, ZHAO Ming-hui,RUAN Ai-guo,QIU Xue-lin
Journal of Tropical Oceanography    2009, 28 (6): 61-67.   DOI: 10.11978/j.issn.1009-5470.2009.06.061
Abstract2149)      PDF(pc) (4891KB)(1676)       Save

Ocean Bottom Seismometer (OBS) deployed in the seafloor can record information of ocean ambient noise, and typhoon can generate elastic waves propagating through the seafloor directly or indirectly. These factors cause great changes on OBS recording data to some extent. The OBS data during the process of typhoon was analyzed, and the methods of optimum filter were used in order to separate signals. After those work, we found that wind wave and ground swell were well recorded by short-period OBSs for the first time, and a new mode which typhoon affected seafloor ambient noise was put forward. We get three preliminary conclusions from above analysis: (1) Wind wave and ground swell caused by typhoon have their own distinctive modes to affect seafloor ambient noise;(2)The range and extent of seafloor ambient noise are obviously different which have been strengthened by two above waves;(3)Short-period OBSs can clearly record the information of ground swell, whose dominating period is 6—8 seconds and its energy is generally steady (we call it “8-second phenomenon); These results will have great significance for the future research on marine seismology and other aspects of oceanography.

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Cited: Baidu(4) CSCD(5)
Internal-wave characteristics of strong bottom currents at the sand-wave zone of the northern South China Sea and its role in sand-wave motion
XIA Hua-yong,LIU Yu-qiang,YANG Yang
Journal of Tropical Oceanography    2009, 28 (6): 15-22.   DOI: 10.11978/j.issn.1009-5470.2009.06.015
Abstract2146)      PDF(pc) (2386KB)(1766)       Save

From the 6th March to the 9th April in 2008, serial bottom-current observations were carried out at the sand-wave zone of the continental shelf and slope in the northern South China Sea (SCS). The measurements show that the tidal current and ocean current are weak at the observation sites, but bottom currents as strong as 30-77 cm.s-1 occur frequently. The directions of the strong bottom currents are related to the northwestward propagation of the internal waves in the region. Most of the strong currents are nearly northwestward or nearly southeastward, and the southeastward currents are stronger than the northwestward ones, which corresponds to the feature of downslope flows stronger than upslope ones when internal waves propagating onshore. Rotary power spectral analysis is carried out for the time series of current velocity. The results show that most of the rotary components higher than the frequency of M2 tide have the characteristics of internal-wave flows, further demonstrating that the frequent, strong bottom currents are induced by internal waves. The measurements are used to calculate the motion speed of sand waves. The results also show that the strong currents can initiate the sea bottom sediments, and due to downslope flows stronger than upslope ones, the sand waves move southeastwards at a low speed less than 1.6 m.yr-1. In addition, the authors model the coupled tide-storm bottom current fields in the northern SCS. From the modeling, the bottom currents, driven by strong typhoon and tide, can move the sand waves, but only move them a very short distance during each typhoon process. The direction of the movement is subject to the typhoon route, which is not always southeastward. Therefore, the coupled tide-storm currents are not the major factor to move the sand waves.

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Cited: Baidu(22) CSCD(9)
Simulations of the northern South China Sea using WAVEWATCH Ⅲ and SWAN
JIANG Li-fang,ZHANG Zhi-xu,QI Yi-quan,CHEN Rong-yu
Journal of Tropical Oceanography    2011, 30 (5): 27-37.   DOI: 10.11978/j.issn.1009-5470.2011.05.027
Abstract2141)      PDF(pc) (1139KB)(6212)       Save
We study the applicability of the National Centers Environmental Prediction/University Corporation for Atmospheric Research ( NCEP/NCAR) reanalysis wind field using the buoy data including the wind speed, significant wave height and mean wave period from September 1987 to August 1988 in the northern South China Sea (SCS). To some extent, the NCEP/NCAR reanalysis wind speed is consistent with the buoy data in the northern SCS. Then we assess the simulations using wave models WAVEWATCH Ⅲ (WW3) and Simulating Waves Nearshore (SWAN) forced by the NCEP/NCAR reanalysis data. The results show that the simulations of the significant wave height (SWH) from the two models are almost the same during the monsoon and monsoon transition periods. The simulation of the mean wave period (MWP) from the WW3 is better than that from the SWAN during the monsoon period, while the results are just contrary during the monsoon transition period. The spatial characteristics from the WW3 simulation in the northern SCS are presented. The SWH affected by monsoon shows significant seasonal change in the northern SCS, while the MWP presents certain semi-annual variability.
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Cited: Baidu(11) CSCD(10)


Journal of Tropical Oceanography    2009, 28 (3): 45-53.   DOI: 10.11978/j.issn.1009-5470.2009.03.045
Abstract2121)      PDF(pc) (2767KB)(1799)       Save
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Cited: CSCD(6)
Evaluation of heavy-metal pollution in Shenzhen coastal sediments
DAI Ji-cui,GAO Xiao-wei,NI Jin-ren,YIN Kui-hao
Journal of Tropical Oceanography    2010, 29 (1): 85-90.   DOI: 10.11978/j.issn.1009-5470.2010.01.085
Abstract2098)      PDF(pc) (326KB)(2273)       Save

Based on the field data of Shenzhen coastal surface sediments from 2000–2007, methods of geo-accumulation index and potential ecological risk index are employed to evaluate heavy-metal pollution status in the area. Results show that Shenzhen coastal sediments have been polluted by heavy metals. The quality degree of most coastal sediments are Class II except for the Gushu Coast. The severity of heavy-metal pollution is: the Gushu Coast, the middle of the Shenzhen Bay, the mouth of the Shenzhen Bay, followed by the mouth of the Shatoujiao Bay that is least polluted. Among heavy metals found in the sediments, Cu and Zn are the two most seriously-polluting elements. The average contents of Cu and Zn in Gushu coastal sediments are 128.96mg·kg−1 and 199.40mg·kg−1, belonging to Class III; other coastal areas of Shenzhen belong to Class II. The results also reveal that there are no potential ecological risks for Shenzhen coastal sediments. The order of potential ecological risks is, Hg>Cd>Cu>As>Pb>Cr>Zn.

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Cited: Baidu(14) CSCD(9)
Two sea-surface warming events in the South China Sea during and after El Nino
HUANG Zhuo,XU Hai-ming,DU Yan,XIE Qiang
Journal of Tropical Oceanography    2009, 28 (5): 49-55.   DOI: 10.11978/j.issn.1009-5470.2009.05.049
Abstract2098)      PDF(pc) (4646KB)(2008)       Save

Using monthly products from the International Comprehensive Ocean-Atmosphere Data Set (ICOADS), the International Satellite Cloud Climatology Project (ISCCP), and the Optimum Interpolation Sea Surface Temperature (OISST), the authors investigate the interannual variation of sea-surface temperature (SST) along a meridional transection in the South China Sea (SCS). It is found that the air-sea interaction in the tropical Pacific plays an important role in the SCS SST variation. Taking warming as an example, the SCS SST warms up in the winter of El Nino developing year and again in the following summer. The first SCS warming occurs during the mature phase of El Nino. The decrease in cloudage and increase in net shortwave radiation flux contribute to the SST warming in the winter. The air-sea interaction associated with El Nino has a direct impact on this SCS warming process. The second warming occurs in the summer after the decay of El Nino. The weakening summer monsoon reduces the latent heat flux release and coastal upwelling off the southeastern Vietnam, which could not be attributed to the direct impact of the El Nino.

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Cited: CSCD(11)
Sea spray parameterization used in typhoon simulations
LIU Lei,ZHENG Jing,LU Zhi-wu,ZHANG Yi-tao
Journal of Tropical Oceanography    2010, 29 (3): 17-27.   DOI: 10.11978/j.issn.1009-5470.2010.03.017
Abstract2093)      PDF(pc) (759KB)(3484)       Save

Sea spray, an important factor in the air-sea interaction, plays an essential role in the occurrence and evolution of typhoon. In order to examine the impact of different sea spray parameterizations on typhoon simulations, the Fairall and Andreas schemes were included in the WRF atmosphere model to simulate two typhoons. The results show that the latent and sensible heat fluxes increased greatly in the Fairall scheme. Since the heat construction of the typhoons changed and the warm core was obvious, the dynamic construction changed as well. Relative diff-vortex explains the cause of the change in typhoon's track and the diff-divergence, vortex and the vapor flux affect the intensity of typhoon. The Andreas scheme, which considers the change of roughness in momentum, heat, and moisture with wind speed and relative humidity, has lower latent and sensible heat fluxes than the Fairall scheme, so the intensity of the typhoons is strong. The simulation of track is less impacted by different sea spray parameterizations.

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Cited: Baidu(7) CSCD(6)
Tidal energy fluxes and dissipation in the South China Sea without considering tide-generated potential energy
TONG Jing-quan,LEI Fang-hui,MAO Qing-wen,QI Yi-quan
Journal of Tropical Oceanography    2010, 29 (3): 1-9.   DOI: 10.11978/j.issn.1009-5470.2010.03.001
Abstract2067)      PDF(pc) (853KB)(3841)       Save

The tidal energy fluxes and dissipation of the principal barotropic tidal constituents M2, S2, K1 and O1 over the South China Sea (SCS) are examined in detail using the simulated tidal results of the Estuarine, Coastal and Ocean Model(ECOM). The results show that the M2, S2, K1 and O1 tidal energy fluxes across the Luzon Strait from the west Pacific are 38.93, 5.77, 29.73 and 28.97 GW into the SCS respectively, and the corresponding fluxes across the Karimata Strait into the Java Sea are 2.42, 0.36, 8.67 and 7.86 GW, respectively. There are also M2 tidal energy fluxes of 25.28 GW into the Taiwan Strait from the East China Sea and northwest of the Luzon Strait. The semi-diurnal tidal energy fluxes into the Beibu Gulf of and the Gulf of Thailand (6.52 GW in all) are much weaker than the diurnal tides (24.74GW). There is 12.28GW of diurnal tidal energy flux into the Sulu Sea from the SCS, while 1.92 GW of semi-diurnal tidal energy flux in a contrary direction. The net tidal energy fluxes and bottom boundary layer dissipation, which should be equal to each other in steady state, are not balanced in each area of the SCS. The most convenient management to this is to modulate the bottom friction coefficients, which are calculated to be 0.0023, 0.0024, 0.0023, and 0.0021 for the Taiwan Strait, the Beibu Gulf, the Gulf of Thailand and deep sea areas in the SCS, respectively.

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Cited: Baidu(3) CSCD(5)
Relationship between ENSO events and regional climate anomalies around the Xisha Islands during the last 50 years
YAN Hong,SUN Li-guang,LIU Xiao-dong,QIU Shi-can
Journal of Tropical Oceanography    2010, 29 (5): 29-35.   DOI: 10.11978/j.issn.1009-5470.2010.05.029
Abstract2058)      PDF(pc) (307KB)(2672)       Save

The authors investigate the relationship between ENSO events and regional climate anomalies around the Xisha Islands during the last 50 years. They find that there is evident correlation between ENSO events and the regional climate anomalies. There is a significant positive correlation between air-temperature anomalies and ENSO index (MEI). Power spec-tral analysis shows that the temperature anomalies have similar cycles to the ENSO index. Regarding to rainfall, the annual precipitation in La Niña years is much more than that in El Niño years. As to tropical cyclone, its frequency during El Niño is significantly lower than that during La Niña.

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Cited: Baidu(35) CSCD(10)
A numerical study on hypoxia and primary production in the Pearl River Estuary in summer using the modified RCA water quality model
ZHANG Heng,LI Shi-yu
Journal of Tropical Oceanography    2010, 29 (1): 20-31.   DOI: 10.11978/j.issn.1009-5470.2010.01.020
Abstract2006)      PDF(pc) (1673KB)(2560)       Save

The RCA water quality model was incorporated with the sediment module and the light shading effect due to the high turbidity in the Pearl River Estuary (PRE). The modified RCA water quality model was then applied to the PRE. Results show that the modified RCA model can reproduce the distribution of nutrients, phytoplankton and dissolved oxygen (DO) in the PRE successfully, which means the modified model can capture the main processes of water quality in the PRE. In the wet season, huge amount of fresh water enters the PRE and results in a river plume. Particulate organic matter (POM) deposits intensely in specific areas of western and central shoal of the Lingdingyang Estuary and outside Modaomen as a result of the plumes. Furthermore, high deposition rate of POM in specific areas leads to high sediment oxygen demand (SOD), which coincides with the areas with strong stratification. High SOD and strong stratification lead to hypoxia. On the shelf areas, primary production increases as the suspended sediment concentration decreases, but the increasing primary production does not result in hypoxia as the marine particulate organic carbon (POC) spreads all over the shelf and the stratification is weak.

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Cited: Baidu(4) CSCD(5)
XIANG Rong,CHEN Mu-hong,CHENG Xin-rong, ZHANG Lan-lan, LU Jun,Liu Jian-guo,CHEN Zhong
Journal of Tropical Oceanography    2009, 28 (3): 59-66.   DOI: 10.11978/j.issn.1009-5470.2009.03.059
Abstract1995)      PDF(pc) (4924KB)(1907)       Save
The authors analyzed oxygen and carbon isotope of planktonic foraminifera from surface sediments and plankton tow samples collected from southern South China Sea (SCS) in spring 2002, and discussed their relationship with marine environmental parameters and depositional process. Their results show that Globigerinoides ruber and G. sacculifer have almost the same average δ18O values in the spring tow samples, which are obviously lighter than those in the surface sediments. In the surface sediments, however, the average δ18O value of G. ruber is apparently lighter than that of G. sacculifer, which may be related to gametogenesis calcification of G. sacculifer and seasonal difference of the two species. The average δ18O value of Pulleniatina obliquiloculata is apparently heavier than that of G. ruber and G. sacculifer in both the surface sediments and the upper water, suggesting a large intra-species δ18O gap between the three species. The average δ18O value of P. obliquiloculata in the upper water in spring is about 0.7‰ lighter than that in the surface sediments, possibly due to the winter flourish of P. obliquiloculata that prefers the low temperature of winter water. The average δ13C values of the three species show a similar trend in both the sediments and the upper water, namely, the heaviest for G. sacculifer, the lightest for P. obliquiloculata, and G. rubber in the middle. The difference of δ13C values between the three species may be mainly caused by vital effect. The regional variations of δ18O values of G. ruber and G. sacculifer in the surface sediments show a similar trend, with heavy values in the northwest and gradually lightening to the southeast of the studied area, all accords with the trend of yearly-averaged sea-surface temperature of gradually increasing from northwest to southeast. Both the δ18O and δ13C of P. obliquiloculata show heavier values in the upwelling stations of the studied area. The relationship of δ13C of P. obliquiloculata with nutrient level of the upper-water mass in southern SCS is contrary to that in northern SCS, which needs to be confirmed by future studies.
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The outbreak of Cochlodinium geminatum bloom in Zhuhai, Guangdong
OU Lin-jian,ZHANG Yu-yu,LI Yang,WANG Hua-jie,XIE Xue-dong,RONG Zhi-ming,LÜ Song-hui,QI Yu-zao,
Journal of Tropical Oceanography    2010, 29 (1): 57-61.   DOI: 10.11978/j.issn.1009-5470.2010.01.057
Abstract1987)      PDF(pc) (358KB)(2575)       Save

Blooms of Cochlodinium polykrikoides occur frequently around the world. During October to November, 2006, an unusual bloom of Cochlodinium geminatum occurred in the coastal eutrophicated waters in Zhuhai, Guangdong. The water temperature and salinity in the bloom zone ranged between 23.41-27.54℃ and 15.49-17.92 psu, respectively. The density of C. geminatum increased significantly with water temperature and salinity and reached to the highest density of 1.6×106 ind.L-1. During the latter period of bloom, the decrease of water temperature and the increase of density of Mesodinium rubrum might be responsible for the dissipation of the C. geminatum bloom.

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Cited: Baidu(28) CSCD(9)
Review of eco-development model for mangrove land-based enclosure aquaculture in the Pearl River Estuary
ZHANG Qiao-min,SHI Qi,YU Ke-fu
Journal of Tropical Oceanography    2010, 29 (1): 8-14.   DOI: 10.11978/j.issn.1009-5470.2010.01.008
Abstract1986)      PDF(pc) (266KB)(2418)       Save

The traditional mangrove land-based enclosure aquaculture model originated in the Pearl River Delta is a good example showing how mangroves can be used sustainably. This paper introduces three examples of mangrove land-based enclosure aquaculture at the mouth of the Pearl River Estuary. The first example is about the only operating traditional mangrove land-based enclosure for shrimp farming located in Mai Po Marshes Nature Reserve of Hong Kong and managed by WWF Hong Kong; its history goes back to the mid-1940s and its focus for management strategy has evolved from being commercial culture ponds to performance of multi-ecological functions including feeding habitat for piscivorous water birds, bird-watching, environmental education, as well as shrimp farming. The second example is the mangrove land-based enclosure for traditionally extensive aquaculture trial in the Dawei Bay on the Qi’ao Island of Zhuhai City, regarding measurement and analyses of relationship between the environmental condition change of water level and salinity and the mangrove community dynamics inside land-based enclosure. The third example is the mangrove planting-aquaculture system trial in the Shenzhen Waterlands Resort on the east coast of the Lingdingyang Estuary, including research on water purification function by mangroves. For mangrove protection and management and for marine pollution prevention in the Pearl River Estuary waters, the following suggestions are given: 1) Preventing resolutely the development model of clearing mangrove for aquaculture ponds, and disseminating and applying the eco-development model of land-based enclosure aquaculture or mangrove-friendly aquaculture; 2) Building new land-based enclosure aquaculture demonstration site in major mangrove regions, and exploring mangrove-friendly restoration model in aquaculture pond areas built by clearing mangroves; 3) strengthening relevant scientific research for maximizing comprehensive efficiency of mangrove land-based enclosure aquaculture.

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Cited: Baidu(5) CSCD(1)
Preliminary investigation on the bacteria diversity coupled with the monsoon forced circulation in the South China Sea
Jie LI, Zhiyou JING, Si ZHANG
Journal of Tropical Oceanography    2018, 37 (6): 1-15.   DOI: 10.11978/2017127
Abstract1985)   HTML855)    PDF(pc) (1521KB)(1388)       Save

Ocean dynamic processes in the South China Sea driven by the monsoon are characterized by seasonal and multi-scale variations, which have significant impacts on the evolution of marine ecosystems. Marine bacteria, as an important component of material cycle and energy flow in marine ecosystems, have active responses to the environmental changes associated with multi-scale dynamic processes. The interdisciplinary research on microbial community structures, their dynamic variation and associated physical processes is one of the hot issues in marine sciences, which combines marine microbiology, microbial ecology and physical oceanography. Based on the primary results of the Key Research Program, "Study on bacteria diversity coupled with the monsoon circulation in the South China Sea and significance in microbial oceanography" supported by the National Natural Science Foundation of China, we discuss in this paper current research progress, including coastal upwelling, seasonal thermal fronts, mesoscale eddy, sub-mesoscale processes, and their potential impacts on the marine bacterial diversity and local ecosystem in the South China Sea.

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Cited: CSCD(1)
The characteristics and sources of surface sediments in the Pearl River Estuary and its adjacent shelves
ZHANG Ling,CHEN Fan-rong,YIN Ke-dong,LÜ Ying,YANG Yong-qiang,ZHANG De-rong
Journal of Tropical Oceanography    2010, 29 (1): 98-103.   DOI: 10.11978/j.issn.1009-5470.2010.01.098
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The authors study the characteristics and sources of organic carbon, nitrogen and the hydrolysable amino acids (THAA), total carbohydrates (TCHO), total lipid and acid-insoluble organic compounds (AIOC) in the surface sediments of the Pearl River Estuary (PRE) and its adjacent shelves. The results show that the organic matter in the PRE was mainly derived from mixed sources of terrestrial and aquatic origins, whereas the organic matter in the adjacent shelves was predominantly algal-derived. Terrestrial higher plants were rich in more lignin and cellulose, which were exported to the PRE. As a result, the content of TCHO in the sediment of the estuary was higher than that in the adjacent shelves, while the content of aquatic organic matter in the estuary was close to that in the adjacent shelves. The proportions of THAA and TCHO were 56%, 48% and 19% in plankton, suspended particulate and surface sediment, respectively; suggesting that the organic matter had undergone degradation during the sedimentation to the water-sediment interface.

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Cited: Baidu(21) CSCD(11)
ZHAO Huan-Ting
Journal of Tropical Oceanography    2009, 28 (3): 5-15.   DOI: 10.11978/j.issn.1009-5470.2009.03.005
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The Chinese probably first had the name of the South China Sea (pronounced as “Nanhai” in Chinese, where “Nan” means “south”, “hai” means “sea”) in writing at the time of Wuwang Period (1046 BC-1043 BC) during the Zhou Dynasty. “Nanhai (place name)”, was named for its closeness to the South China Sea (Nanhai), which clearly suggests that the term “Nanhai (place name)” was used later than the term “Nanhai (sea name)”. During Chengwang Period (1042 BC-1021 BC) of the Zhou Dynasty, the famous tribute of black millet (Indian millet), known as the story of “Millet of Nanhai”, was from the “Nanhai (place name)”. In Xuanwang Period (827 BC -782 BC) of the Zhou Dynasty, the name “Nanhai” used in the poem Jiang Han includes both the “Nanhai (sea name)” and “Nanhai (place name)”, which was the first time the name was used in writing. “Nanhai” was then used in Yu Gong of Shang Shu in late Zhanguo Period (475 BC -221 BC), but whether it meant the “Nanhai (sea name)” or not has yet to be confirmed. “Nanhai” was later used in Hai Nei Dong Jing of Shan Hai Jing during the Qin (221 BC -207 BC) and Han (206 BC- AD 220) Dynasties; it was also used in Nan Yue Lie Zhuan of Shi Ji and in an ancient map of early Western Han Dynasty (206 BC- AD 8), where it was definitely referring to the “Nanhai (sea name)”, just like its present meaning. From the Eastern Han Dynasty (AD 8-220) to the Tang (AD 618-907) and Song (AD 960-1279) Dynasties, the “Nanhai” was referred as the “Zhanghai”. Over the Ming (AD 1368-1644) and Qing (AD 1644-1911) Dynasties, the “Nanhai” was called the “Daminghai” and “Daqinghai” by foreigners. Then the “Nanhai” was translated as the “South China Sea” by foreigners and the name “South China Sea” has been widely used all over the world. Unfortunately, some Chinese translate the English name “South China Sea” directly into Chinese as the “Nanzhongguohai”, which is then used by some books, magazines and media. The “Nanhai” was first found and named by Chinese around 3 000 years ago, which has been well recognized all over the world. The “Nanhai” is the only name used in official publications and maps by the most recent governments of China. The “Nanhai” is also the only name used in the related administrative departments, armed forces and institutions. Therefore, the “Nanhai” should not be called the “Nanzhongguohai”. People using the name “Nanzhongguohai” can be considered ignorant to Chinese history, which may mislead people to think that the “Nanhai” (South China Sea) was first found and named by foreigners, and further confuse the Chinese sovereignty on the Nanhai.
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Cited: CSCD(2)
Effects of salinity and nutrition on growth, respiration and excretion of Litopenaeus vannamei
SHEN Yu-chun,CHEN Zuo-zhou,WU Zao-he,HUANG Xiang-hu
Journal of Tropical Oceanography    2010, 29 (5): 111-118.   DOI: 10.11978/j.issn.1009-5470.2010.05.111
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An experiment was conducted to determine the effects of salinity and dietary protein levels on growth, respiration and excretion of Litopenaeus vannamei. The composition of body muscle was analyzed. The results showed that the growth rate was increased with the increase of dietary protein level, but the survival rate was not significantly affected (P>0.05). The survival rate was not significantly increased with the increase of salinity in the different dietary protein levels (P>0.05). The growth rate was increased with the increase of salinity in a low salinity levels, the highest growth rate was obtained at 18, then it was decreased with further increase of salinity. The analysis of body composition showed that the crude protein, crude fat and ash content significantly increased with the increase of salinity (P<0.05), but moisture and nitrogen-free extract content decreased significantly (P<0.05). Crude protein and ash content significantly increased with the increase of dietary protein level (P<0.05), but moisture and nitrogen-free extract content decreased significantly (P<0.05), crude fat was not significantly affected (P>0.05).The oxygen consumption rate and the ammonia excretion rate were affected significantly by the different salinity and dietary protein levels (P<0.05). The oxygen consumption rate was significantly decreased with the increase of salinity and dietary protein level (P<0.05), appearance time of the high peak was 2−3 h after ingestion. The ammonia excretion rate increased with the increase of dietary protein level, but decreased with the increase of salinity, appearance time of the high peak was 2 h after ingestion. The oxygen-nitrogen ratio was affected significantly by the different salinity and the dietary pro-tein levels (P<0.05).

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Cited: Baidu(5) CSCD(4)
Development of international marine observation system and construction of deep-sea station in China
LI Jian ,CHEN Rong-yu,WANG Sheng-an,MAO Hua-bin,HE Yun-kai,SUI Dan-dan,XIE Qiang,SHI Ping,YANG Yue-zhong,WANG Dong-xiao
Journal of Tropical Oceanography    2012, 31 (2): 123-133.   DOI: 10.11978/j.issn.1009-5470.2012.02.017
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Since the 1980s, marine observation has become much more diversified, capable of delivering three-dimensional and real-time data. National and regional observing systems have been playing important roles in key regions of the oceans. Going with the development of technology and concept innovation, regional marine observation system has been widely used and gradually improved. International marine observation stations, such as the Irish Sea Coastal Observatory, the Carolinas Regional Coastal Ocean Observing System (RCOOS), and the Victoria Experimental Network Under the Sea (VENUS) are great examples, which consist of three-dimensional and real-time data, combined with marine ecosystem, physical, biological and chemical models. Some other examples, such as the American “ North-East Pacific Time-series Undersea Networked Experiments ” (NEPTUNE), the “ European Seafloor Observatory Network ” (ESONET) and the Japanese “ Advanced Real-time Earth monitoring Network in the Area ” (ARENA) are deep-sea network systems, which make th e ocean observatory more comprehensive. Under these international backgrounds, the first deep-sea observation research network station in China-Xisha Marine Research Station was completed in 2008 and has started offering real-time data. The observation system mainly includes automatic weather station, mooring in the western boundary, biological traps, Xisha surface ocean observation system, and Xisha Ocean Optics observation system. Because of the complexity of marine structure, harsh working environment and resource shortages, marine observation could be a high risk task. With the knowledge of the domestic and international marine observation systems reviewed in this study, it is hoped that Chinese marine observation system could be developed and improved to achieve more rapid progress.
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Cited: Baidu(8) CSCD(8)
Analysis and evaluation of nutrition composition of double-headed parrotfish Cheilinus undulates
OU You-jun,LI Jia-er
Journal of Tropical Oceanography    2010, 29 (3): 97-102.   DOI: 10.11978/j.issn.1009-5470.2010.03.097
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Nutritive composition in muscle of wild double-headed parrotfish Cheilinus undulates was investigated in this study. Results showed that the contents of moisture, crude protein, crude lipid, and crude ash in fresh muscle of C. undulates were 80.97%, 18.38%, 0.10% and 0.49%, respectively. A total of 18 kinds of common amino acid in the muscle was detected with the 15.7%(wet weight); the content of essential amino acids was 39.37% of the total ones, which met the Food and Agriculture Organization of the Untied Nations/World Health Organization (FAO/WHO) standard. The ratio of branch-chain amino acids to aromatic amino acids was 2.5654, close to the normal value of that in human. According to nutritive evaluation in amino acid score(AAS), the first limited amino acid was threonine (Thr), the second was tryptophane (Trp), and the value of essential amino acid index (EAAI) was 68.46. The total content of four smelled amino acids was 31.85%. The content of EPA + DHA in fatty acids was 21.86%。The elements of Na, K, Ca, Mg, Fe, Cu, Zn were found in muscle, which were essential for the human. In conclusion, this research indicated that C. undulates is a nutritive sea-food fish.

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Cited: Baidu(11) CSCD(9)
Effect of heating rate on the upper incipient lethal temperature for copepods
JIANG Zhi-bing,ZENG Jiang-ning,CHEN Quan-zhen,LIAO Yi-bo,GAO Ai-ge
Journal of Tropical Oceanography    2010, 29 (3): 87-92.   DOI: 10.11978/j.issn.1009-5470.2010.03.087
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To explore how heating rate influences the thermal tolerance of copepods and to recommend heating rate criteria during copepod upper incipient lethal temperature (UILT) tests, four copepod species (Calanus sinicus, Labidocera euchaeta, Euchaeta concinna, Centropages dorsispinatus) collected from the Yueqing Bay were studied in laboratory under different heat-ing rates (1℃•h-1, 0.1℃•min-1, 1℃•min-1, and abrupt exposure). The results showed that thermal tolerance of the same copepod species varied with heating rate, and all the experimental copepods decreased in number from a heating rate of 0.1℃•min-1 to-wards quicker or slower heating rates. Thus, the rate of 0.1℃•min-1 was considered as the standard heating rate for UILT experi-ments. In the trial conducted at 0.1℃•min-1, the 24h-UILT of L. euchaeta, C. dorsispinatus, E. concinna and C. sinicus were 31.0℃, 29.6℃, 29.1℃ and 27.7℃, respectively; the 48h-UILT of L. euchaeta, C. dorsispinatus, E. concinna and C. sinicus were 30.1℃, 29.5℃, 28.6℃ and 27.3℃, respectively. Differences of thermal sensitivity between these animals were all significant.

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Cited: Baidu(6) CSCD(3)
Effects of N to P ratio on the growth of two red tide diatom Skeletonema costatum and Thalassiosira weissflogii
LIU Hao,Gao Yong-li,YIN Ke-dong,YUAN Xiang-cheng,XU Jie,HARRISON Pau
Journal of Tropical Oceanography    2010, 29 (6): 92-97.   DOI: 10.11978/j.issn.1009-5470.2010.06.092
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The growth character and ecophysiology of Skeletonema costatum and Thalassiosira weissflogii were studied in culture medium of different ambient ratios of N to P (4︰1, 16︰1, 64︰1). Bacth cultures of these two phytoplankton species were conducted to examine their growth rates, Chl-a, DIN︰P (dissolved inorganic nitrogen and phosphorus) and PON︰P (particular organic nitrogen and phosphorus) during incubation periods. The results showed that the N︰P ratio could signifi-cantly influence the growth of Skeletonema costatum and Thalassiosira weissflogii. The ratio of N to P could evidently influ-ence these two diatom species. The growth rate, cell numbers and Chl-a of these two species were obviously lower with N-limitation (N︰P=4︰1) than those with P-limitation (N︰P=64︰1). The results suggested that T. weissflogii was more sensitive to N-limitation than S. costatum. Although cultured in different N︰P ratios medium, the N︰P composition of these two algal species hardly changed with the medium N︰P ratio. Due to the luxury consumption, the cells could still take up excessive nutrients for living when other nutrients were depleted by phytoplankton, which resulted in different N︰P ratios of phytoplankton. N-limited medium reduced the N︰P ratio of the algal cells, while P-limited medium increased the N︰P ratio of the phytoplankton cells significantly.

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Cited: Baidu(16) CSCD(18)
Influence of Nitrogen and Phosphorus on Phytoplankton Community Structure in Dapeng’ao Bay, Daya Bay
II Species Composition
ZHU Ai-jia,HUANG Liang-min,LIN Qiu-yan,XU Zhan-zhou,
Journal of Tropical Oceanography    2009, 28 (6): 103-111.   DOI: 10.11978/j.issn.1009-5470.2009.06.103
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In situ survey in the surface of Dapeng’ao Bay (Daya Bay), combined with nutrient enrichment bioassays were conducted in April-May (spring), August (summer) and November (autumn), 2005 in order to better understand the potential influence of nitrogen (NO3- or urea) and phosphate(PO43-)on the species composition of phytoplankton in this area in different seasons. In spring, the abundance of phytoplankton in Dapeng’ao Bay was the highest but the diversity index was the lowest among the three seasons. The dominant species had significant seasonal variations. The horizontal variation of species composition was more significant in autumn than that in any other season. Results showed that the succession among the dominant species Rhizosolenia alata f. genuina, Leptocylindrus danicus and Chaetoceros cinctus from spring to summer may due to the change of the condition of nitrogen (N) and PO43-. In summer, there should be factors other than nitrogen or PO43- controlling the succession between the dominant species Thalassionema nitzschioides and Thalassiosira weissflogii. Although phosphorus is consider to be the most limiting factor for the growth of phytoplankton in this area, the treatment with high N:P ratio in summer did not showed any phosphorus (P) limiting effect, and the variation of N:P ratio had little effect on the species composition. Further more, the potential impact of nitrogen on the species composition was more significant than PO43- in autumn.

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Numerical Models of the Tectono-Thermal Evolution of Rift Basins and Their Applications to the Northern South China Sea
Journal of Tropical Oceanography    2009, 28 (6): 41-51.   DOI: 10.11978/j.issn.1009-5470.2009.06.041
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Numerical models are the basis for quantitative modeling of the tectono-thermal evolution of sedimentary basins. Due to the importance of rift basins in scientific research and petroleum exploration, extensive studies have been devoted to building numerical models for rift basins. This paper summarizes the models that have great influence or play an important role in the study of the passive continental margin of the South China Sea, including the most fundamental model of McKenzie, and the models of finite-rate stretching, simple shear stretching, flexural cantilever stretching, depth-dependent stretching, and multiphase stretching. Special emphasis was placed on their basic assumptions, application conditions, and numerical formulations for the geothermal field and basin subsidence. The similarities, differences, and correlations of these models were expounded. Finally, the applications of the models in studying the rift basins in the northern South China Sea were briefed, which may help to advance our understanding of the methods and applications of the numerical models.

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Cited: CSCD(2)
Surface salinity distribution of the Kuroshio in the East China Sea and its influencing factors
REN Hui-ru,KANG Jian-cheng,LI Wei-jiang,AN Yan,ZHANG Jian-ping,WANG Tian-tian
Journal of Tropical Oceanography    2011, 30 (5): 55-61.   DOI: 10.11978/j.issn.1009-5470.2011.05.055
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Using the World Ocean Atlas 2005 by the National Oceanic and Atmospheric (NOAA) published in 2007, topography database in 2006 by the National Geophysical Data Center (NGDC), and the grid precipitation data of the Asian region by the Japan Agency for Marine-Earth Science and Technology ( JAMSTEC) published in 2003, the authors explore three-dimensional techniques for oceanic data analysis and figures manifestation with Matlab computer programs. They find that the surface salinity distribution of the Kuroshio in the East China Sea (ECS) varies monthly. First, the salinity at surface is higher in December through March, and is lower in June to September; the salinity in the rest of year is in between. Second, the salinity is the highest near the east side of the Kuroshio in the East China Sea where is closer to Ryukyu Island . The salinity at surface is affected by surface temperature, rain, and Changjiang diluted water. The salinity at surface of the Kuroshio in the East China Sea is mainly influenced by surface temperature near the shelf of contentious in November to February. Surface salinity is impacted by precipitation at small-scale in January and summer, which is in areas south of 25癗 and also near 30癗 where the ECS-Kuroshio flows into the Tokara Strait. Summer runoff of Changjiang diluted water affects most to the surface salinity of the Kushiro in a fan-shaped zone, resulting the maximum runoff in July and the corresponding minimum salinity on surface of the Kuroshio in the fan-shaped zone in the East China Sea .
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Cited: Baidu(11)
Studies on distribution of fungal endophyte in mangrove plant Aegiceras corniculatum
DENG Zu-jun,CAO Li-xiang,VRIJMOED LILIAN L P,LU Yong-jun,ZHOU Shi-ning
Journal of Tropical Oceanography    2010, 29 (3): 77-81.   DOI: 10.11978/j.issn.1009-5470.2010.03.077
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Five hundred and twenty-nine isolates of fungal endophytes were isolated from the lamina, mid-rib, bark and the xylem of stem of Aegiceras corniculatum, among them 297 isolates in wet and 232 in dry season. The taxa of preponderant fungal endophyte communities differed in the four organs of Aegiceras corniculatum: in lamina are Penicillium and Aureobasidium, in mid-rib are Penicillium and Cladosporium, in bark are the sterile groups, and in xylem of stem are Aureobasidium and Cladosporium. These results indicated that there was some degree of organ specific in distribution of fungal endophytes. The preponderant taxa of endophyte assemblages in organs were different between wet and dry seasons. For example, in lamina, wet season were Penicillium and Aureobasidium, but dry season were sterile groups B and C. It showed that the density and the taxa of the endophyte communities in Aegiceras corniculatum were influenced by the environmental factors such as precipitation, temperature, humidity, and intensity of sunlight.

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Cited: Baidu(9) CSCD(5)
The distribution, enrichment and pollution assessment of heavy metals in surface sediments of sea areas around the Nanao Island
QIAO Yong-min,GU Ji-guang,YANG-Yang,HUANG Chang-jiang
Journal of Tropical Oceanography    2010, 29 (1): 77-84.   DOI: 10.11978/j.issn.1009-5470.2010.01.077
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The Nanao Island is the main island of the Nanao County, Guangdong province, and the sea area around the island is important for local social and economic development. A survey of heavy metal content, distribution, enrichment and pollution state in sediments was conducted in May and July 2004. A total of eleven sediment samples were collected from mariculture base: Houjiang Bay, Baisha Bay and A tourist resort: Qingao Bay along the coast of the Nanao Island. The results showed that the contents of heavy metals were Cd:, Cr:, Cu:, Ni:, Pb: 35.67, Zn:, much higher than those in similar bays of economically developed coastal areas and lower than those of offshore areas without anthropogenic impact. Average heavy metals in sediment tended to be lower in inner bays than at the mouth of the bay, and higher at aquaculture sites than non-aquaculture ones. However, there was no significant difference among studied bays, suggesting that river input maybe the main source of heavy metals in sea areas around the Nanao Island, which resulted in the enrichment of Cu (Cf = 2.75) and Pb (Cf = 2.27) that are representative elements of sewage. Based on the marine sediment quality standard, sediment quality criteria and baseline values for the United States Pacific Coast, the heavy metal pollution near the Nanao Island generally presented a slightly higher level. However, more attentions should be paid to the potential pollution effects.

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Cited: Baidu(42) CSCD(8)
Spatial distribution of demersal fishery resources in the continental shelf of the northern South China Sea
LIU Wei-da,LIN Zhao-jin,JIANG Yan-e,HUANG Zi-rong
Journal of Tropical Oceanography    2011, 30 (5): 95-103.   DOI: 10.11978/j.issn.1009-5470.2011.05.095
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Based on the survey data of four cruises by otter trawl in the continental shelf of the northern South China Sea from October 2006 to September 2007, spatial distributions of species composition, species richness D, and catch rate of fishery resource were analyzed. The richest species was found along Zhanjiang transect (405 species), and the fewest species was found along Shantou transect (337 species). Species number showed a skewed normal distribution with the water depth, and more species were found at depths of 40—80m. The trend of spatial distribution of species richness D was the same as the species number. In the total catch, weight composition of the three groups of fish, cephalopoda, and crustacean was 80:12:8. For the transects distribution, the highest ratio of fish in the composition was found along Zhujiang transect, the highest ratio of cephalopoda was found along Zhanjiang transect, and highest ratio of crustacean was found along Yangjiang trasect. For water depths distribution, the composition of fish increased with depth, a higher composition of cephalopoda was found at 40—100m, and the compostion of crustacean at 10—20m was distinctly higher than at other depths. There were six main dominant species in fish. Of the dominant species, Nemipterus bathybius was dominant in 90?120m depth, while Navodon xanthopterus in 60—90m, Upeneus bensasi in 60—120m, Daicocus peterseni in 120—200m, Polynemus sextarius in 30—60m, and Harpodon nehereus in 10—30m. For transect distribution, high catch rate of fish was found in the Zhujiang estuary and western Guangdong waters, and the lowest was found along Shantou transect. For depth distribution, fish catch rate increased with water depth. Catch rate of cephalopoda was found higher in western Guangdong and Zhujiang estuary than in eastern Guangdong waters. Cephalopoda catch rate increased with water depth within 100m and decreased below 100m. The highest catch rate of crustacean was found along Yangjiang transect, and was distinctly lower along other transects. By comparison with the exist-ing data, succession of species was distinct after the decline of fishery resources in the northern South China Sea. While the resource of large-scale and well quality species substantially decreased, the resource of small-scale and bad quality species increased obviously. Under the pressure of fishing catch power in coastal waters, the distribution of fish catch rate showed the trend of increasing with depth.
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Cited: Baidu(8) CSCD(14)
Seasonal variability of salinity budget in the southeastern Arabian Sea
ZHANG Yu-hong,XU Hai-ming,DU Yan,WANG Dong-xiao
Journal of Tropical Oceanography    2009, 28 (5): 66-74.   DOI: 10.11978/j.issn.1009-5470.2009.05.066
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Based on the monthly mean data of Simple Ocean Data Assimilation (SODA) product, the authors analyze the seasonal salinity budget of surface layer in the southeastern Arabian Sea., The salinity variation in the region cannot be explained by surface freshwater flux. The salinity budgets in two typical regions show that horizontal advection dominates salinity variation, decreasing the salinity in winter and increasing it in summer, except for the coastal region off western India where the surface freshwater flux decreases salinity in summer. During winter, the northeast monsoon current advects fresher water from the Bay of Bengal into the Arabian Sea along the same latitude and then transports the low saline-water northward, resulting in salinity reduction in the surface layer of the southeastern Arabian Sea. During summer, southwest monsoon current advects high-salinity water in the northwestern Arabian Sea southeastward, increasing the salinity in the surface layer of the southeastern Arabian Sea. In the southeastern Arabian Sea, salinity variation of the surface layer is prominently stronger in winter than in summer.

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Cited: Baidu(11) CSCD(10)

YANG Xiao-qiu1,2,SHI Xiao-bin1,XU He-hua1,XU Xing3,LI Guan-bao4,GUO Xing-wei5,LUO Xian-hu3

Journal of Tropical Oceanography    DOI: 10.11978/j.issn.1009-5470.2009.04.028
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Selecting an effective and convenient simplified model for dual-probe seafloor heat-flow meter is the theoretical basis for optimizing dual-probe structure, which is very important to improve heat-flow calculation accuracy. Basing on the finite element numerical model about seafloor pulsing dual-probe, the authors analyzed in detail how the dual-probe’s heat pulse duration, heat generation rate, thermal properties, length and radius affect model errors in three line source simplified models. The selected effective and convenient simplified model is the one whose model errors are the least. The results are as follows: 1) in dual-probe heat pulse method, Pulsed Finite Line Source (PFLS) model is a more practical simplified model, in which the model errors from pulse duration and probe length can be avoided; 2) in the PFLS model, model errors from probe thermal conductivity can be neglected. In addition, model errors can recede with probe spacing increasing, probe radius decreasing and probe volume heat capacity approaching the surrounding medium. When surrounding medium temperature change can be detected and recorded effectively by the sensor probe, probe heat pulse power cannot affect model errors.
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Characteristics of phytoplankton community in the Pearl River Estuary during saline water intrusion period
LI Kai-zhi,HUANG Liang-min,ZHANG Jian-lin,YIN Jian-qiang,LUO Lin
Journal of Tropical Oceanography    2010, 29 (1): 62-68.   DOI: 10.11978/j.issn.1009-5470.2010.01.062
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The authors analyzed species composition, distribution of species richness and phytoplankton density based on the data collected from two cruises carried out during saline water intrusion period from the end of 2007 to the beginning of 2008 at both spring and neap tides in the Pearl River Estuary. In addition, influence of environmental factors on phytoplankton community was discussed. Seventy-six species in total were identified, including 38 diatoms, 18 green algae, 14 dinoflagel-lates, 4 cyanobacteria and 2 euglenas. In general, the distribution of species richness decreased from inner section to outer section of the Pearl River Estuary. The species richness of phytoplankton was higher at neap tide than at spring tide, and it distributed unevenly among different water layers. The dominant species were mainly freshwater diatoms, such as Melosira granulate, Melosira granulata v. angustissima, Cyclotella sp. and Thalassiosira sp. The dominant species were very out-standing in the inner section of the Pearl River Estuary with the characteristics of uneven density distribution and low even-ness index value. The mean phytoplankton densities at spring and neap tides were 53.80×104 and 62.21×104ind.L-1, and the ranges of cell density were from 1.48×104 to 290.41×104 and from 1.52×104 to 283.62×104ind.L-1, respectively. Phyto-plankton density decreased from the inner to outer sections of the Pearl River Estuary, and the density of diatom was the highest among different groups during both spring and neap tides. The community of phytoplankton presented clear tidal pe-riodicity. Environmental factors such as salinity and nutrients played an important role in the composition and distribution of phytoplankton during saline water intrusion period in the Pearl River Estuary.

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Cited: Baidu(9) CSCD(10)
Phylogenetic diversity analysis of bacteria in the deep-sea sediments from the Bashi Channel by 16S rDNA BLAST
SUN Hui-min,DAI Shi-kun,WANG Guang-hua,XIE Lian-wu,LI Xiang
Journal of Tropical Oceanography    2010, 29 (3): 41-46.   DOI: 10.11978/j.issn.1009-5470.2010.03.041
Abstract1902)      PDF(pc) (444KB)(3594)       Save

Using modified DNA extraction and purification method, high-quailty environmental DNA was obtainedfrom deep-sea sediments of the Bashi Channel in the northern South China Sea. Diversity of eubacteria was studied by PCR, ARDRA and sequence analysis of 16S rDNA and compared with the published sequences in the GenBank. Based on the ARDRA profile generated, 118 clones from the 16S rDNA library were divided into 23 operational taxonomic units (OTUs). Phylogenetic analysis showed that the representative clones of the 23 OUT fell into nine groups: Actinobacteria (26%), Proteobacteria (22%), Planctomycetes (18%), Verrucomicrobia (4.5%), Sphingobacteria (4.5%), Nitrospira (4.5%), Chloroflexi (5%), Firmicutes (4.5%), and Acidobacteria (4.5%), repspectively. Among the 23 clones, there was no clone being identical to the known 16S rDNA sequences in the Ribosomal Database Project small subunit RNA database. In this clone library, 11 clones had less than 95% similarity to rDNA sequences retrieved from the DNA databases. The results suggested that bacterial population in the Bashi Channel of the northern South China Sea is very diverse in phylogeny and there are the massive unknown microorganism deserve further studying and exploration as valuable resources.

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Cited: Baidu(9) CSCD(9)
Study of fine-scale mixing in intermediate and deep layers of the South China Sea
Zhumin Lu, CHEN Gui-Yang,SHANG Xiao-Dong
Journal of Tropical Oceanography    2009, 28 (3): 21-28.   DOI: 10.11978/j.issn.1009-5470.2009.03.021
Abstract1889)      PDF(pc) (5436KB)(2035)       Save
Using ADCP (Acoustic Doppler Current Profiler) and CTD (Conductivity/Temperature/Depth profiler) data acquired in August 2007 and the Gregg model, the authors estimate the internal-wave-scale mixing in the intermediate and deep layers of the South China Sea. They also use the Thorpe scale to study the vertical overturns in these layers and the corresponding diapycnal diffusivity. The results by the two methods are consistent, showing that the dissipation rate and diapycnal diffusivity in the upper 400m near the Luzon Strait are larger than those at 18°N, while there is no obvious distinction in the mediate and deep layers. These results, therefore, suggest that there may be active internal waves resulting in intensive internal wave mixing and vertical overturning in the upper 400m near the Luzon Strait. The dissipation rate and diapycnal diffusivity estimated by the Gregg model are at the level of 10–9 W?kg–1 and 10–6 m2?s–1, respectively. At most of the CTD stations surveyed, there always exists vertical overturning in the intermediate and deep layers and the diapycnal diffusivity estimated by the Thorpe scale does not decrease with depth. The characteristics of the fine-scale mixing reported here will facilitate the understanding of the intermediate and deep layers of the South China Sea.
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Cited: CSCD(3)
Estimation of suspended sediment concentration at Zhujiang River Mouth based on decomposition of mixing spectrum
LIU Da-zhao,CHEN Chu-qun,LIU Fen-fen ,GOGN Jie-qiong
Journal of Tropical Oceanography    2009, 28 (5): 43-48.   DOI: 10.11978/j.issn.1009-5470.2009.05.043
Abstract1887)      PDF(pc) (1243KB)(1606)       Save

Although there has some been effort to retrieve suspended sediment concentration (SSC) by using remote sensing data, there are some limitations for the application of this technology in estuary waters partly due to the low spatial resolution of remote sensing data, such as the Moderate Resolution Imaging Spectroradiometer data. By comparison, the EO-1 Hyperion instrument, which is capable of resolving 196 spectral bands over the range of 400–2500 nm, with 10-nm wide band and 30-m spatial resolution, has a great potential in studying suspended sediments in estuaries. The authors study the SSC at the Zhujiang River Mouth using the Hyperion images obtained on December 4, 2006, along with the real time remote sensing reflectance. The results show that the mixing spectral decomposition model is a good choice for estimating the SSC using remote sensing data.

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Cited: Baidu(9) CSCD(5)
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