2009 Vol. 28, No. 1

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Articles
A Lagrangian mean theory on coastal sea circulation with inter-tidal transports Ⅱ. Numerical Experiments
JU Lian, JIANG Wensheng, FENG Shizuo
2009, (1): 1-14.
Abstract:
The results of the new concept of coastal sea circulation are demonstrated by numerical simulations for the first time. The numerical experiments in three types of rectangular model seas illustrate the dependence of circulation on tidal phases due to the convectively nonlinear effect which is estimated by a newly defined drift dispersion in-dex. Then, the present theory is applied in the Bohai Sea of China. At the Bohai Straits and the Huanghe River mouth area the circulation direction even reverses owing to different initial tidal phases which shows that the the-ory copes with nonlinearity well. The calculated M2 tide-induced residual circulation shows that a clockwise gyre exists in the center of an anticlockwise gyre in the central Bohai Sea due to the topographic features. In the Bo-hai Gulf the tide induced circulation shows a 3D structure with outflow at the surface and the inflow at the bottom which can partly explains the spread of the Huanghe River fresh water out of the Bohai Gulf and the inflow of the sediment from the Huanghe River.
Identification of CO2 disposal locations in an ocean general circulation model of the North Pacific
XU Yongfu, AOKI Shigeaki, HARADA Koh
2009, (1): 15-24.
Abstract:
A basin-wide ocean general circulation model of the North Pacific is used to identify which location is more effi-cient for ocean CO2 sequestration in the North Pacific. Four injection depths at each one of fifteen locations are chosen. In terms of effectiveness index (EI) and escape factor (EF), it is clear that the effectiveness increases with increasing latitude at the end of the 50 a injection period. Site-by-site differences in the EI can be over 9% for the 1 000 m injection depth in the western North Pacific at the end of 50 a of continuous injection. The difference is much larger for the 500 m injection. The difference decreases with increasing injection depth. However, the site-by-site difference is small for the injection in the eastern North Pacific. The sequestration is more efficient for the injection in the east than in the west. For the 500 m injection depth, the difference in ef-fectiveness between the west and the east is over 10% at the end of 50 a injection period. The largest concentra-tion of sequestered CO2 increases with increasing injection depth. For the injection in both the western and cen-tral North Pacific, the largest exchange flux always appears to be at about 42°N, 150°E, whereas for the injec-tion in the eastern area the large flux appears to be in the equatorial region (120°W).
On tectonic movement in the South China Sea during the Cenozoic
LIN Changsong, CHU Fengyou, GAO Jinyao, TAN Yonghua
2009, (1): 25-36.
Abstract:
The tectonic movement taking place at the end of Cretaceous and the beginning of Cenozoic had opened the Ce-nozoic phase of polycyclic tectonic movements, then the whole crust of the South China Sea had been mainly subjected to the regional stress field of tectonic tension, which was characterized by rifting depression. Seven times of regional tectonic movement and sedimentation had been assembled into a geological development history of polycyclic oscillation. Especially, the tectonic movements were strongly intensified at the end of Cretacious and the beginning of Paleagene, between Late Eocene and Mid-Oligocene, during Mid- and Late Miocene. These three times of tectonic movement had built the most important regional tectonic interfaces in the South China Sea. Crust movements of the South China Sea were the result and epitome of interaction of the Eurasia, Pacific and Indo-Australia plates, that is, they were introduced by polycyclic changes of directions, rates and strengths of lithospheric movements and asthenospheric flows across the Pacific and Indo-Australia plates.
Denitrification in Qi'ao Island coastal zone, the Zhujiang Estuary in China
WANG Hu, ZHOU Huaiyang, PENG Xiaotong, YANG Qunhui, QIN Chaomei, YIN Xijie, CHEN Guangqian
2009, (1): 37-46.
Abstract:
Samples of sediments and the overlying water were collected in the Qi'ao Island coastal zone, the Zhujiang (Pearl River) Estuary (ZE). Denitrification rates, sediment oxygen demand (SOD), and fluxes of inorganic nitrogen compounds were investigated with N2 flux method, using a self-designed continuous flow through and auto-sampling system. The results indicate that the denitrification rates varied between 222 and 908 μmol/(m2·h) with an average of 499 μmol/(m2·h). During incubation, the sediments absorbed dissolved oxygen in the overlying water with SOD ranging from 300 to 2 363 μmol/(m2·h). The denitrification rates were highly correlated with the SOD (r2=0.77) regardless of the NO3-+ NO2- concentrations in the overlying water, organ-ic carbon contents in sediments and water temperature, suggesting that the SOD was probably the main environ-mental factor controlling the denitrification in the Qi'ao Island coastal zone. There was a net flux of NO3-+ NO2- into the sediments from the overlying water. The NH4+ flux from sediments into water as the result of mineraliza-tion was between 12.3 and 210.3 μmol/(m2·h),which seems limited by both organic carbon content in sedi-ment and dissolved oxygen concentration in the overlying water.
Terrestrial flux in sediments from the Okinawa Trough estimated using geochemical compositional data and its response to climate changes over the past 35 000 a
MENG Xianwei, LIU Yanguang, DU Dewen, SHI Xuefa
2009, (1): 47-54.
Abstract:
Terrestrial supply to marginal seas is a function of interaction between land and ocean in response to climate changes. Terrestrial flux in sediments, therefore, is potential not only to reflect the paleoceanographic evolution of sedimentary basin, but also to reveal the paleoclimatic changes in source regions. Sediments from the Okina-wa Trough were quantitatively partitioned into terrestrial, volcanic and biogenitic end members using constrained least-squares technique for geochemical compositional data. Combined with the density of bulk sediments and sedimentation rate, the terrestrial flux in sediments from the Okinawa Trough since the last 35 000 a was esti-mated. Based on surface seawater temperature (SST) and sea level changes over the past 35 000 a, the re-sponse of terrestrial flux to the climate changes was discussed. It is demonstrated that the terrestrial supply to the Okinawa Trough mainly derived from Chinese landmass via the Changjiang (Yangtze) River and controlled by sea level changes. During the post-glaciation, the terrestrial flux was the lowest in response to the highest sea level stand. During the last glacial maximum (LGM), the terrestrial flux was not so high as previously expec-ted, indicating the arid climatic condition in source region was responsible for lowering the Changjiang River's runoff during that time. During the deglaciation, the terrestrial flux increased in response to a quick rising of the sea level, probably implicating occurrence of down-slope transport. The four events characterized by slight in-crease in terrestrial flux exactly correspond to the LGM, Heinrich events (H1, H2, H3), respectively.
Characterization of marine microplankton communities of Qingdao coastal areas using randomly amplified polymorphic DNA (RAPD)
GAO Shan, HU Xiaozhong, CHEN Zigui, XU Henglong, YI Zhenzhen, LIN Xiaofeng, LI Jiqiu
2009, (1): 55-61.
Abstract:
Microplankton communities of three coastal sites of Qingdao, Shandong Province, China were investigated using RAPD (random amplified polymorphic DNA) molecular markers and morphological observations. Eight RAPD-primers were selected to amplify the DNA polymorphy. The genetic distances inferred from the pairwise similari-ties were calculated for the phylogenetic tree construction. Meantime, the traditional microscopic determination, a way of visualizing the species composition, was performed to detect the major taxa of microplanktons from all samples. Results showed that:(1) the band sharing index values were in the range of 0.504 2-0.763 2 among samples from the same sampling site at different time scales, while 0.406 5-0.685 7 among the samples from different stations at the same time scales, indicating that spatial variations of microplankton communities were more pronounced than temporal ones; (2) samples from the same station basically clustered together, cor-responding to the geographic distribution of the sampling sites; (3) diversity derived from genetic and morpho-logical data did not correspond with each other well.
A culture-dependent survey of thermophilic bacteria from hot springs in Xiamen area in China
YANG Bo, OUYANG Jianping, AO Jingqun, CHEN Xinhua
2009, (1): 62-71.
Abstract:
Microbes are believed to play important roles in ecosystem function in many environments. The hot springs of Xiamen Island are close to the Xiamen Sea, and may have some characteristics different from those of inland hot springs. Microbes living in the hot springs of Xiamen may have new characteristics. However, little is known about microbial communities of hot springs close to the Xiamen Sea. A culture-dependent survey of microbial population in the Xiamen hot springs was performed by using an approach combining total cellular protein profile identification and 16S rRNA gene sequencing. A total of 328 isolates of bacteria were obtained from liquid and sediment samples from the Xiamen hot springs, including neutrophilic thermophilic bacteria and moderately thermophilic acidophiles. Neutrophilic thermophilic bacteria, which grow at a temperature range of 55-90℃ including Rhodothermus marinus (Strain 1), Thermus thermophilus (Strain 2), Thermus thiopara (Strain 3), Geobacillus stearothermophilus (Strain 4), Geobacillus thermoleovorans (Strain 5), and Pseudomonas pseudoalcaligenes (Strain 6), were recovered by 2216E plates. Moderately thermophilic acidophiles, which can grow at temperatures above 50℃ and a pH range of 1.8-3.5 such as Alicyclobacillus acidoterrestris (Strain 8), Sul-f obacillus acidophilus (Strain 9), and Sulf obacillus thermosulf idooxidans (Strain 10), were isolated on selective solid medium containing sulfur and Fe2+. Among these strains, Rhodothermus marinus, Thermus thermophilus and Geobacillus stearothermophilus are not only thermophiles, but also halophiles. One bacterium strain (Strain 6) shared 99% nucleotide sequence homology with Pseudomonas pseudoalcaligenes on the 16S rRNA gene se-quence, but was quite different from Pseudomonas pseudoalcaligenes in biological characteristics, suggesting that it may represent a novel thermophilic species. Results indicated that various species of neutrophilic thermophiles and moderately thermophilic acidophiles were widely distributed in the Xiamen hot springs and that Rhodothermus marinus and Thermus thermophilus dominated the cultivable microbial community.
Interspecies competition for nutrients between Prorocentrum donghaiense Lu and Skeletonema costatum (Grev.) Cleve in mesocosm experiments
ZHU Mingyuan, XU Zongjun, LI Ruixiang, WANG Zongling, SHI Xiaoyong
2009, (1): 72-82.
Abstract:
Three mesocosm experiments were conducted in the East China Sea during blooms of Prorocentrum donghaiense Lu in May of 1998, 2002 and 2003 to examine the role of nutrients in the formation of these harmful algae blooms (HABs). The results showed that there was interspecies competition between P. donghaiense and Skeletonema costatum (Grev.) Cleve. The cell number of P. donghaiense and S. costatum accounted for about 85% and 11% of the total cell number of phytoplankton respectively at the beginning of the experiment in May 1998. In May 2002, at the beginning of the experiment, the cell number of P. donghaiense accounted for 55% -66% of the total and S. costatum accounted for 32%-42%. The density of P. donghaiense and S. costatum was over 95% and 1%-5% respectively in May 2003. The results of these three mesocosm experiments showed that the dominant species in this specific community varied with different nutrient availability. Under low-phos-phate conditions, the dominant species was P. donghaiense, while S. costatum became dominant in phosphate-replete cases. The average growth rate (1.08 d-1) of S. costatum in exponential growth phase was higher than that (0.39 d-1) of P. donghaiense. In the mesocosm, S. costatum predominated in the mesocosm by its rapid growth. When phosphorus was depleted, the cell number of S. costatum dropped rapidly, while P. donghaiense Lu decreased more slowly. The results from mesocosm experiment may explain why:(1) P. donghaiense bloom usually occurs in May, when phosphate concentration is low; (2) the bloom of S. costatum appears in early spring and summer time, when nutrients increase with increasing Changjiang River (Yangtze River) runoff; (3) the bloom of S. costatum is short and that of P. donghaiense Lu can last more than a month in the East China Sea.
Effects of wind waves of the Pacific westerly on the eastern Pacific wave transport
DENG Zeng'an, WU Kejian, ZHAO Dongliang, YU Ting
2009, (1): 83-88.
Abstract:
There exists a tongue-shaped swell-dominance pool known as Swell Pool (SP) in the Eastern Pacific region. The monthly-mean wave transports (WT) for each month of 2000 is computed using the wave products of ECMWF reanalysis data. By comparing the 2000 monthly-mean WT and monthly-mean wind field from QUICKSCAT, large differences are found between the wave transport direction and the wind direction over the Eastern Pacific. This may serve as an evidence for the existence of the SP in this region. The work done in this study indicates that the sources of swell in the Tropical Eastern Pacific (TEP) are in the westerly regions of the Southern and Northern Pacific.
Interactions of nonlinear gravity waves and uniform current in Lagrangian system
HSU Hung-Chu, CHEN Yang-Yih, LI Meng-Syue, TSENG Wen-Jer
2009, (1): 89-98.
Abstract:
The particle trajectory on a weakly nonlinear progressive surface wave obliquely interacting with a uniform cur-rent is studied by using an Euler-Lagrange transformation. The third-order asymptotic solution is a periodic bounded function of Lagrangian labels and time, which imply that the entire solution is uniformly-valid. The ex-plicit parametric solution highlights the trajectory of a water particle and mass transport associated with a particle displacement can now be obtained directly in Lagrangian form. The angular frequency and Lagrangian mean lev-el of the particle motion in Lagrangian form differ from those of the Eulerian. The variations in the water particle orbits resulting from the oblique interaction with a steady uniform current of different magnitudes are also investi-gated.
Research Notes
Spatial distributions and seasonal variations of particulate phosphorus in the Jiaozhou Bay in North China
YUAN Huamao, SONG Jinming, LI Ning, LI Xuegang, ZHANG Ying, XU Sisi
2009, (1): 99-108.
Abstract:
Based on the measurements of particulate phosphorus (PP) in the Jiaozhou Bay from May 2003 to April 2004, the spatial distribution, seasonal variation and biogeochemical characteristics of PP were investigated to under-stand the fates and roles of phosphorus in the Jiaozhou Bay ecosystem. The concentration of the total PP ranged from 0.07 to 2.09 μmol/dm3. The concentration of POP was from 0.01 to 1.83 μmol/dm3, with an average of 0.32 μmol/dm3, which accounted for 49.6% in total PP. The concentration of PIP was from 0.01 to 1.49 μmol/dm3, with an average of 0.33 μmol/dm3, which accounted for 50.4% in total PP. In general, the con-centrations of PP in surface water show obvious seasonal variations in the Jiaozhou Bay. POP was the highest in spring, which derived from the accumulation of phyto-detritus and was the lowest in autumn, which was decom-posed into seawaters to participate the recycle of phosphorus. PIP was the highest in spring and summer and was the lowest in autumn and winter. PIP was mainly influenced by river input in the inner bay but POP derived from autochthonous source in the outer bay. Overall, the concentrations of PP in the inner bay were higher than those in mouth and the outer bay. In the inner bay, the concentrations of PP with the area near the shore were higher than those in the center of the bay. Totally PP showed the decreasing trend with depth especially in spring and winter. The high value of PP emerged in 20 and 10 m corresponding to summer and autumn, respec-tively. The changes of POP showed hysteretic effect compared with the changes of Chl a in the investigated year. However, according to the change of Chl a, the second high value of POP which should be emerged in October was missing due to the remineralization of POP and participation in the recycle of phosphorus, which lead to the high concentration of orthophosphate in seawaters.
Aequorea taiwanensis n. sp. (Hydrozoa, Leptomedusae) and mtCOI sequence analysis for the genus Aequorea
ZHENG Lianming, LIN Yuanshao, LI Shaojing, CAO Wenqing, XU Zhenzu, HUANG Jiaqi
2009, (1): 109-115.
Abstract:
Aequorea taiwanensis, a new hydrozoan species from the Taiwan Strait was described using morphological and molecular characteristics. Both morphological and mitochondrial cytochrome oxidase subunit I (mtCOI) data supported A. taiwanensis n. sp. as a valid species. Sequence divergence and genetic distance of A. taiwanensis n. sp., A. papillata and A. conica were analysed based on the mtCOI gene sequences. The mtCOI sequences from these three species of the genus Aequorea showed high variation frequency, with sequence divergences ran-ging from 9.10% to 11.9%, and pairwise genetic distances ranging from 0.097 to 0.130. MtCOI sequence analysis provided diagnostic molecular systematic characteristics for accurate identification and discrimination of the species of Aequorea or their populations, and will be used to resolve evolutionary relationships among them. It was suggested that 10% -20% pairwise mtCOI sequence differences indicated the species-level divergence among congeneric species in the Hydromedusae.
Report of Prionospio complex (Annelida: Polychaeta: Spionidae) from China's waters, with description of a new species
ZHOU Jin, LI Xinzheng
2009, (1): 116-127.
Abstract:
Nine species of Prionospio complex are recorded from China's waters, including one new species and six newly recorded species. Prionospio (Prionospio) pacifica sp. nov., is characterized by having first and forth pairs of branchiae pinnate, second and third pairs of apinnate, ventral crest on Setiger 9 and dorsal crests on Setigers 10-25. Apoprionospio kirrae (Wilson, 1990), Prionospio (Aquilaspio) convexa Imajima, 1990, Prionospio (Minuspio) multibranchiata Berkeley, 1927, Prionospio (Prionospio) bocki Søderstrøm, 1920, Prionospio (Prionospio) dubia Maciolek, 1985 and Prionospio (Prionospio) paradisea Imajima, 1990 are recorded for the first time from China's waters.