Spatial Diversity of Bacterioplankton Communities in Surface Water of Northern South China Sea

The South China Sea is one of the largest marginal seas, with relatively frequent passage of eddies and featuring distinct spatial variation in the western tropical Pacific Ocean. Here, we report a phylogenetic study of bacterial community structures in surface seawater of the northern South China Sea (nSCS). Samples collected from 31 sites across large environmental gradients were used to construct clone libraries and yielded 2,443 sequences grouped into 170 OTUs. Phylogenetic analysis revealed 23 bacterial classes with major components α-, β- and γ-Proteobacteria, as well as Cyanobacteria. At class and genus taxon levels, community structure of coastal waters was distinctively different from that of deep-sea waters and displayed a higher diversity index. Redundancy analyses revealed that bacterial community structures displayed a significant correlation with the water depth of individual sampling sites. Members of α-Proteobacteria were the principal component contributing to the differences of the clone libraries. Furthermore, the bacterial communities exhibited heterogeneity within zones of upwelling and anticyclonic eddies. Our results suggested that surface bacterial communities in nSCS had two-level patterns of spatial distribution structured by ecological types (coastal VS. oceanic zones) and mesoscale physical processes, and also provided evidence for bacterial phylogenetic phyla shaped by ecological preferences.     

中国南中国海海岸湿地的保护和管理

中国南中国海湿地是中国各类生态系统中生物多样性最为丰富的地区之一,也是中国人口稠密、经济发达的地区。范围包括广东省、香港特别行政区、澳门特别行政区、广西壮族自治区和海南省等5个行政区。该区海岸湿地总面积约为1.54×104km2。海岸湿地处于海陆的交错地带,是脆弱的生态敏感区。由于受人口增加和经济发展的巨大压力,中国南中国海湿地破坏严重,退化趋势明显。本文在对中国南中国海地区海岸湿地的现状、类型及湿地退化的主要原因进行分析的基础上,提出中国南中国海地区海岸湿地资源保护与管理的建议,以便切实保护中国南中国海沿海多样化的湿地类型,持续发挥其生态服务功能。     

Distribution Patterns of Strongylocentrotus Sea Urchins along the Coast of Eastern Kamchatka

The distribution patterns of three sea urchin species of the genus Strongylocentrotus in relation to depth, type of substrate, surf action, and to some hydrological parameters were studied along the coast of eastern Kamchatka and in adjacent waters in 1984–1996. The sea urchin Strongylocentrotus polyacanthus dominated the open coast on rocky subintertidal sites with increased surf action and standard oceanic salinity. S. droebachiensis prevailed in shoals with lower salinity, higher water temperature and lower turbulence (enclosed and semienclosed bays). S. pallidus dominated at depths corresponding to the position of the cold intermediate layer deeper than 30–50 m with normal oceanic salinity and lower temperature.     

Archaeal Diversity and Spatial Distribution in the Surface Sediment of the South China Sea

Archaea represent a significant portion of biomass in the marine sediments and may play an important role in global carbon cycle. However, the identity and composition of deep sea sediment Archaea are unclear. Here, we used the archaeal 16S rRNA gene primers to determine the diversity and community structure of Archaea from shallow water (<100 m) and deep water (>1500 m) sediments in the South China Sea. Phylogenetically the archaeal community is separated between the shallow- and deep sea sediments, with the former being dominated by the Thaumarchaeota and the latter by the Marine Benthic Group B, E and the South African GoldMine Euryarchaeotal Group as well as Thaumarchaeota. Sand content showed significant correlation with Thaumarchaeota, suggesting that the porous media may create an oxic environment that allowed these aerobic organisms to thrive in the surface sediments. The carbon isotope composition of total organic carbon was significantly correlated to the distribution of archaeal groups, suggesting that Archaea overall may be constrained by the availability or sources of organic carbon in the sediments of the South China Sea.     

中国沿海鼠尾藻遗传多样性分析

鼠尾藻是我国沿海重要经济海藻,本文采用AFLP分子标记技术对我国辽宁、山东和浙江沿海的野生鼠尾藻共120个个体进行了遗传多样性分析.5对引物共得到340个位点,多态性位点比例分别为旅顺盐场群体82.31%、大连长海群体78.97%、山东海阳群体91.03%和浙江洞头群体94.87%,平均杂合度分别为0.2088、0.1862、0.2505和0.2736.Shannon多样性指教分别为0.3273、0.2974、0.3911和0.4236,群体间的遗传距离在0.0301～0.1437之间.分析结果表明,4个群体的遗传多样性水平均出现了一定程度的降低.     

China,Vietnam, and the South China Sea: Disputes and Dispute Management

This article examines recent developments in the South China Sea; in particular, the China-Vietnam relationship. The developments are presented in the broader context of the Sino-Vietnamese approach to managing border disputes since full normalization of relations in late 1991. The challenges for China and Vietnam in managing their disputes and related tension in the South China Sea are also discussed.     

Universalizing the Law of the Sea in the South China Sea Dispute

This article argues that a resolution of the maritime disputes in the South China Sea must be based upon a universalist framework where the maritime interests of the world are upheld. The article discusses the universalist framework of the 1982 United Nations Convention on the Law of the Sea (UNCLOS) and the universalist approach taken by the Tribunal on 12 July 2016 in the South China Sea Arbitration regarding the extinguishment of a state's “exceptionalist” maritime claims and the adoption of strict criteria for the characterization of features at sea.     

大鹏湾浮游动物种群密度变化的一次数学模拟

大鹏湾浮游动物种群密度变化的一次数学模拟郭远琼（暨南大学华侨医院计算机室,广州５１０６３３）黄伟建韩博平齐雨藻（暨南大学水生生物研究所,广州５１０６３２）ＴｈｅＩｄｅｎｔｉｆｉｃａｔｉｏｎｏｆａＭｅｃｈａｎｉｓｍＭｏｄｅｌｏｆｔｈｅＺｏｏｐｌａｎｋｔ...     

我国沿海缢蛏群体遗传结构的mtDNA-COⅠ分析

采集了我国沿海共计9个缢蛏(Sinonovacula constricta)地理群体的197个样本,分别是北部组群的3个群体:辽宁省庄河群体(ZH),天津市汉沽群体(HG),山东省海阳群体(HY);中部组群的3个群体:江苏省盐城群体(YC),上海市崇明县东滩群体(DT)和堡镇群体(BZ);以及南部组群的3个群体:浙江省宁波群体(NB),浙江省台州群体(TZ)以及福建省宁德群体(ND)。利用线粒体COⅠ标记分析了9个群体的遗传多样性和遗传分化。结果表明,在共计197个个体中检测到125个单倍型和96个变异位点,核苷酸多样性指数位于2.1764～7.4970之间,其中中部组群的群体遗传多样性指数最高。AMOVA分析结果显示,组间遗传变异量占总变异的80.27%,18.74%来自于群体内,只有0.99%来自于组内群体间。群体间遗传分化系数位于0.0219～0.8706之间,不同群体间具有一定的遗传分化,尤其是中部群体与其他群体间遗传分化值达到了0.8以上,为极高度分化。遗传距离和聚类结果显示,北部3群体和南部3群体首先聚在一起,之后与中部3群体聚类。     

一株南海北部深海沉积环境真菌00457的鉴定及其活性研究

从南海深海沉积环境样品中分离到一株编号为00457的真菌,基于形态学特征、ITS和5.8S rDNA序列比对分析,鉴定该菌株为白黄笋顶孢霉( Acrostalagmus luteoalbus).活性研究表明,其代谢产物粗浸膏的卤虫致死活性明显,并具有一定强度的抑菌和DPPH自由基清除活性.此外,研究还发现代谢产物粗浸膏在25-100℃持续加热不超过30 min时,卤虫致死活性成分稳定,但在100C持续加热超过60 min后卤虫致死活性成分显著减少,而一定强度的紫外光照射90 min内则无显著影响.     

Community shift of ammonia-oxidizing bacteria along an anthropogenic pollution gradient from the Pearl River Delta to the South China Sea

The phylogenetic diversity and abundance of ammonia-oxidizing beta-proteobacteria (beta-AOB) was analyzed along an anthropogenic pollution gradient from the coastal Pearl River Delta to the South China Sea using the ammonia monooxygenase subunit A (amoA) gene. Along the gradient from coastal to the open ocean, the phylogenetic diversity of the dominant genus changed from Nitrosomonas to Nitrosospira, indicating the niche specificity by these two genera as both salinity and anthropogenic influence were major factors involved. The diversity of bacterial amoA gene was also variable along the gradient, with the highest in the deep-sea sediments, followed by the marshes sediments and the lowest in the coastal areas. Within the Nitrosomonas-related clade, four distinct lineages were identified including a putative new one (A5-16) from the different sites over the large geographical area. In the Nitrosospira-related clade, the habitat-specific lineages to the deep-sea and coastal sediments were identified. This study also provides strong support that Nitrosomonas genus, especially Nitrosomonas oligotropha lineage (6a) could be a potential bio-indicator species for pollution or freshwater/wastewater input into coastal environments. A suite of statistical analyses used showed that water depth and temperature were major factors shaping the community structure of beta-AOB in this study area.     

Allometric differences on the shell shape of two scorched mussel species along the Atlantic South American Coast

Scorched mussels (Bivalvia: Mytilidae) are an important component of rocky shore assemblages around the world. The mussel beds of the mid-intertidal coasts of the south-western Atlantic are composed of two species of scorched mussels, which dominate the physiognomy and structure of the rocky shore communities. The present study investigates the variation in the shell-shape allometric trajectories of both species of mussels throughout their distributional range in the southwestern Atlantic coast, from latitude 34°S to 53°S. Shells of Brachidontes rodriguezii were collected at two Uruguayan localities and four Argentinean localities, while shells of Perumytilus purpuratus were collected at six Argentinean localities. Shell shapes of the specimens were studied by geometric morphometrics using landmark and semi-landmark methods. Different evolutionary histories and thermal regimes characterize these two species. Brachidontes rodriguezii seems to have a long history in the region and is present in a restricted area, the warm temperate region of the south-western Atlantic, while P. purpuratus seems to have a recent history and is present in a wide thermal range, involving the cold-temperate regions of the south-western Atlantic and south-eastern Pacific and the warm-temperate region of the south-eastern Pacific. Based on these considerations, we prompt the hypothesis that allometric trajectories of P. purpuratus shell shape is more variable and adapted to a specific habitat than B. rodriguezii. The impact of allometry was larger in P. purpuratus than in B. rodriguezii. Graphical evidence was gathered, showing that these two species differ in allometric growth forms and that the allometric shell morphology changes reflect environmental constraints and adaptation. While the intertidal mussel beds of the South American coasts are ecologically similar in appearance, we found that the allometric variation of the scorched mussels occurs in response to diverging evolutionary processes such as phenotypic plasticity in P. purpuratus and canalization in B. rodriguezii.     

大亚湾大型底栖动物的群落结构

利用2004年3月、5月、9月和12月的大型底栖动物定量采样数据,对大亚湾大型底栖动物的群落结构进行研究.结果表明,大亚湾大型底栖动物大致可分为3个群落,分别分布于湾顶及湾中大部分海域、湾中部和湾口海域,湾中部海域群落的变化较为显著.大型底栖动物整体群落结构的季节变化总体较小,但雨季对大型底栖动物群落的影响较大,存在较明显的干湿季差异.大亚湾海域生态环境受到明显的扰动,处于扰动状态中的大型底栖动物群落稳定性较差;湾顶和湾中大部分海域内的群落Ⅰ,为大亚湾的主体群落,以软体动物为主,种类组成单一、季节变化小,以小鳞帘蛤Veremolpa micra和粗帝汶蛤Timoclea scabra 为特征种.该群落的稳定性最差,处于较强烈的扰动之中;稳定分布于湾口的群落Ⅲ稳定性最好,未受到扰动,以多毛类为主,种类组成较为复杂、变化较大;湾中部海域大型底栖动物群落结构变化较为复杂,主要变化区域为马鞭州附近海域.该群落系经强烈的人为扰动后,经次生演替而形成的新群落,其种类组成的季节变化非常显著,各季的种类几乎完全不同,群落的独立性和抗干扰能力均较弱;与1980's相比,大亚湾大部分区域内大型底栖动物基本保持了原有的群落,但群落稳定性大幅下降,群落的分布范围和种类组成发生较大程度的改变,主体群落组成呈明显的简单化趋势.在人类活动影响下,湾内同一区域内群落完全演替、湾中部海域出现新的群落.     

Identification of two novel esterases from a marine metagenomic library derived from South China Sea

The demand for novel biocatalysts is increasing in modern biotechnology, which greatly stimulates the development of powerful tools to explore the genetic resources in the environment. Metagenomics, a culture independent strategy, provides an access to valuable genetic resources of the uncultured microbes. In this study, two novel esterase genes designated as estA and estB, which encoded 277- and 328-amino-acid peptides, respectively, were isolated from a marine microbial metagenomic library by functional screening, and the corresponding esterases EstA and EstB were biochemically characterized. Amino acid sequence comparison and phylogenetic analysis indicated that EstA together with other putative lipolytic enzymes was closely related to family III, and EstB with its relatives formed a subfamily of family IV. Site-directed mutagenesis showed that EstA contained classical catalytic triad made up of S146-D222-H255, whereas EstB contained an unusual catalytic triad which consisted of S-E-H, an important feature of the subfamily. EstA exhibited habitat-specific characteristics such as its high level of stability in the presence of various divalent cations and at high concentrations of NaCl. EstB displayed remarkable activity against p-nitrophenyl esters and was highly stable in 30% methanol, ethanol, dimethylformamide, and dimethyl sulfoxide, making EstB a potential candidate for industrial applications.     

南海生物多样性的保护

海洋对我们有很大的魅力,仅就生物多样性而言,我国是联合国《生物多样性公约》的最早缔约和制定保护生物多样性行动计划的国家之一,保护生物多样性是我国人民必须履行的共同义务,也是关系子孙后代生存的大事.1地理位置南海位于我国东南,面积约350 km2,平均深度为1,212 m,最大深度为5,377 m.它是一个长轴东北-西南向的边缘海,由西沙、中沙、东沙和南沙群岛构成,四大岛礁群散布其中,西南还有北部湾和泰国湾两大海湾.南海东临菲律宾群岛,北靠华南大陆,南接加里曼丹和苏门答腊,西接马来半岛和中南半岛.南海周边共有9个海峡,与东海、太平洋、苏禄海、爪哇海和印度洋相连通,地理位置非常重要,是欧、亚、非通道,在安全航运、经贸往来、环境保护、资源开发和军事战略等方面都具有非常重要的地位.     

Microbial diversity in surface sediments of the Xisha Trough, the South China Sea

Microbial communities were obtained from the surface sediments of the Xisha Trough using the culture-independent technique. The characteristics of the 16S rDNA gene amplified from the sediments indicated that archaeal clones could be grouped into Euryarchaeota and Crenarchaeota, respectively. Two archaeal groups, Marine Crenarchaeotic GroupI and Terrestrial Miscellaneous Euryarchaeotal Group, were the most dominant archaeal 16S rDNA gene components in the sediments. The remaining components were related to the members of Marine Benthic Group B, Marine Benthic Group A, Marine Benthic Group D, Novel Euryarchaeotic Group and C3. The bacterial clones exhibited greater diversity than the archaeal clones with the 16S rDNA gene sequences from the members of Proteobacteria, Planctomycetes, Actinobacteria, Firmicutes, Chloroflexi, Acidobacteria, candidate division OP8, Bacterioidetes/Chlorobi and Verrucomicrobia. Most of these lineages represented uncultured microorganisms. The result suggests that a vast amount of microbial resource in the surface sediments of the South China Sea has not been known.     

南海西沙海槽表层沉积物微生物多样性

利用非培养的分子技术研究了西沙海槽表层沉积物中的微生物群落.沉积物中扩增的古菌16S rDNA 序列分属两个大类:泉古生菌(Crenarchaeota)和广古生菌(Euryarchaeota).以Marine Crenarchaeotic GroupⅠ (古菌16S rDNA文库的49.2%)和Terrestrial Miscellaneous Euryarchaeotal Group (16.9%)为主要类群;其余为Marine Benthic Group B (9.7%)、 Marine Benthic Group A (4%)、 Marine Benthic Group D (1.6%)、Novel Euryarchaeotic Group (0.8%)和 C3(0.8%).细菌克隆子多样性明显高于古菌,16S rDNA序列分别来自变形杆菌(Proteobacteria)(细菌16S rDNA文库的30.5%)、浮霉菌(Planctomycetes)(20.3%)、放线菌(Actinobacteria)(14.4%)、厚壁菌(Firmicutes)(15.3%)、屈桡杆菌(Chloroflexi)(8.5%)、酸杆菌(Acidobacteria)(3.4%)、candidate division OP8 (2.5%)、拟杆菌/绿菌(Bacterioidetes/Chlorobi)(1.7%)和疣微菌(Verrucomicrobia)(1.7%).变形杆菌为优势类群(包括Alpha-和Delta-Proteobacteria亚群).多数克隆子为未培养细菌和古菌.结果表明南海表层沉积物中蕴含大量未知的微生物资源.     

China's U-Shaped Line in the South China Sea Revisited

Despite its existence on the Chinese maps for more than six decades, the U-shaped line, as a traditional maritime boundary line of China in the South China Sea, has never received a wide recognition in the world community, much less by the other claimant states in the South China Sea. The U-shaped line is a legal conundrum not only for China but also for the world community, particularly after the map with the U-shaped line, together with China's Notes Verbale with respect to the claims to the outer continental shelves made by Malaysia and Vietnam, were submitted to the UN Commission on the Limits of Continental Shelf in May 2009. This article discusses China's recent practice relating to the U-shaped line as well as the external factors that affect the validity of the line and tries to unravel the legal puzzle posed by the line.