Large variations in the Holocene marine radiocarbon reservoir effect reflect ocean circulation and climatic changes

Accurate radiocarbon dating of marine samples requires knowledge of the marine radiocarbon reservoir effect. This effect for a particular site/region is generally assumed constant through time when calibrating marine 14C ages. However, recent studies have shown large temporal variations of several hundred to a couple of thousand years in this effect for a number of regions during the late Quaternary and Holocene. Here we report marine radiocarbon reservoir correction (ΔRΔR) for Heron Reef and Moreton Bay in southwestern (SW) Pacific for the last 8 ka derived from 14C analysis of 230Th-dated corals. Most of our ΔRΔR for the last ∼5.4 ka agree well with their modern value, but large ΔRΔR variability of ∼410 yr (from trough to peak) with possible decadal/centennial fluctuations is evident for the period ∼5.4–8 ka. The latter time interval also has significant variations with similar features in previously published ΔRΔR values for other sites in the Pacific, including southern Peru–northern Chile in southeastern (SE) Pacific, the South China Sea, Vanuatu and Papua New Guinea, with the largest magnitude of ∼920 yr from SE Pacific. The mechanisms for these large ΔRΔR variations across the Pacific during the mid-Holocene are complex processes involving (1) changes in the quantity and 14C content of upwelled waters in tropical east Pacific (TEP) (frequency and intensity of ocean upwelling in the TEP, and contribution of Subantarctic Mode Water to the upwelled waters, which is influenced by the intensity and position of southern westerly winds), and (2) variations in ocean circulation associated with climate change (La Niña/El Niño conditions, intensity of easterly trade winds, positions of the Intertropical Convergence Zone and the South Pacific Convergence Zone), which control the spreading of the older upwelled surface waters in the TEP to the western sites. Our results imply the need for employing temporal changes in ΔRΔR values, instead of constant (modern) values, for age calibration of Holocene marine samples not only for the SW Pacific sites but also for other tropical and subtropical sites in the Pacific.

On the roles of the northeast cold surge, the Borneo vortex, the Madden-Julian Oscillation, and the Indian Ocean Dipole during the extreme 2006/2007 flood in southern Peninsular Malaysia

The mid-December 2006 to late January 2007 flood in southern Peninsular Malaysia was the worst flood in a century and was caused by three extreme precipitation episodes. These extreme precipitation events were mainly associated with strong northeasterly winds over the South China Sea. In all cases, the northeasterlies penetrated anomalously far south and followed almost a straight trajectory. The elevated terrain over Sumatra and southern Peninsular Malaysia caused low-level convergence. The strong easterly winds near Java associated with the Rossby wave-type response to Madden-Julian Oscillation (MJO) inhibited the counter-clockwise turning of the northeasterlies and the formation of the Borneo vortex, which, in turn, enhanced the low-level convergence over the region. The abrupt termination of the Indian Ocean Dipole (IOD) in December 2006 played a secondary role as warmer equatorial Indian Ocean helped in the MJO formation.

The induced flow field by internal solitary wave and its action on cylindrical piles in the stratified ocean

The induced flow fields by internal solitary waves and its actions on cylindrical piles in density stratified ocean with a basic density profile and a basic velocity profile are investigated. Some results, such as the time evolution of flow fields and hydrodynamic forces on the piles are yielded both by theoretical analysis and numerical calculation for general and specific cases. Several kinds of ambient sea conditions of the South China Sea are specified for numerical simulation. Moreover, the effects of relative density difference, depth ratio and wave steepness on maximal total force and total torque are analyzed.

南海北部沙波运移的观测与理论分析

针对南海北部海域特点建立了模拟该区域小尺度沙波运移过程的准三维力学模型.以多波束海底地貌扫描数据和水文资料为基础,预测了研究区域沙波的运移,其结果在沙脊脊沟处与实际观测一致,而在脊背上与实际观测值存在差异.分析表明,本文所提出的物理模型可以用于预测南海海域以推移质泥沙运动为主的小尺度沙波运移规律.这一结果对该区域海底管线等工程设计是很有意义的.

Studies on the mouth size of fish larvae. Method and conclusions only [Translation from: Bulletin of the Japanese Society of Scientific Fisheries 36, 353-368, 1970]

This study was conducted to look into the relationship between mouth size and the total length of larval fish, and the growth in total length of larval fish in one or within a one-year period. Study material was gathered in the South China Sea, the Bay of Bangkok and the Vietnamese coast. This translation focuses on methods and conclusions of the original (longer) paper.

Length-weight relationship of Gulf of Thailand fishes

The length-weight relationship of 26 fish species belonging to 17 families obtained from the Gulf of Thailand was examined. As seven species were obtained from different survey periods and three were from two different locations, seasonal and geographic variations of the equation between body weight W and total length L, W = aL super(b), were examined. The b values of the 27 species were tested for their significant differences from the value of 3; this confirmed that a few species showed significant differences of b value from 3. It is suggested that the 'cube law (b = 3)' can be applied to the length-weight relationship of most fishes in the Gulf of Thailand, with a few exceptions. This was confirmed by the analysis of b values from 72 additional species from the South China Sea area.

3.0～2.0Ma B. P.南海南部深海沉积物孢粉记录及其对全球变化的响应

为了重建东亚季风区域2.5MaB.P.前后植被和气候变化的历史，更好地了解低纬度地区植被变化及其对全球变化的响应，本研究选择了南海南部ODP1143站深海沉积物中的孢粉样品进行研究。通过高分辨率（7ka）的孢粉样品的分析研究，建立起3.0～2.0MaB.P.时段南海深海沉积孢粉组合序列，系统建立了这一时段植被演替序列。在此基础上，重点研究了2.5MaB.P.前后气候变化在南海周边地区植被演替中的响应，为探索和揭示东亚古季风及古环境演变提供了孢粉学依据。 ODP 1143站位于南沙海区，北纬9º22´，东经113º17´，深海柱状样采于水深2772m的大陆坡。本研究以生物地层学和氧同位素年代学为依据建立了年龄框架，对1143站135～95m（3.0～2.6 Ma B. P.）深海沉积中的孢粉样品进行了分析，建立了3.0～2.0MaB.P.时段南海深海沉积孢粉组合序列。孢粉样品处理方法主要是用盐酸去掉钙质和氢氟酸浸泡溶解硅质后，再用筛子将样品在超声波发生器中震荡过滤。孢粉的鉴定和统计在光学透视显微镜下完成。研究结果表明： 1、孢粉谱的主要特征是沉积率变化显著。与3.0～2.6 Ma B. P. 相比，2.6～2.0 Ma B. P.各类型花粉及孢子沉积率均有显著提高。该结果表明2.6 Ma B. P.南海海平面有显著下降，可与北半球冰盖形成、东亚季风增强相对应。 2、2.6 Ma B. P.以来，各类型孢粉沉积率变化与深海氧同位素分期相对应，代表了多次冰期-间冰期旋回。该结果表明南海海平面曾有多次上升和下降。 3、频谱分析结果表明，3.0～2.0 Ma B. P.存在0.1 Ma（偏心率）和46.9ka（斜率）的周期。

Developmental characters of Psettina Iijimae (Jordan and Starks), bothid flat fishes - Pisces

Post larval stages of Psettina Iijimae ranging from 1.8 mm NL to 44.6 mm SL collected during Naga Expedition and International Indian Ocean Expedition (IIOE) are described. The characteristics which help to identify larval stages of Psettina are: the presence of pigmented urohyal appendage in early stages which is progressively reduced during flexion stages and which disappears in later postflexion stages, the meristics, the spines on urohyal and posterior basipterygial processes and the absence of spines on cleithra. The P. iijimae can be distinguished by the presence of spines on the median fin rays which differentiate near the baseosts along the dorsal and ventral body wall much before the fin rays. The larvae of P.iijimae were more abundant in the Gulf of Thailand compared to South China Sea and Indian Ocean.

遥感研究南海台风引起的冷迹特征

海表面温度（Sea Surface Temperature, SST）是海洋生态环境变化的重要因子，也是海洋观测研究的最重要的因子之一。海表温度场表征了海洋热力、动力过程和海洋与大气相互作用的综合结果，是反映海气热量、动力和水汽交换的重要参量，也是气候变化及海洋营养盐浓度和初级生产力的重要影响因子。台风过后通常会在上层海洋引起冷迹，即台风路径附近的海表温度降低。海表温度的变化是台风与海洋之间能量交换的关键，对于台风的产生，演化和强度变化有非常重要的作用。因此，研究上层海洋对台风的响应，特别是海表温度对台风的响应过程有非常重要的科学意义。本研究主要利用微波SST逐日数据资料统计研究了海表面温度对南海台风的响应过程，并分析了中尺度涡（特别是气旋性涡）对台风所引起的降温幅度和降温位置的影响作用。在此研究基础上初步尝试提出了一种新的量化台风降温效应的方法。 首先，本研究以1998-2009年总共12年内经过中国南海的92个台风为研究对象，利用逐日连续的微波TMI及TMI-AMSER海表温度数据资料分析了92个台风所引起的最大降温幅度以及冷迹位置的分布特征。统计结果表明有64个（69.6%）台风引起了海表温度明显的降低（降温≥2oC），而对最大降温出现的位置进行分析发现：有超过半数（56个）的台风引起的最大降温位于台风路径的附近或路径右侧，同时还有8个（8.7%）台风引起的最大降温明显位于路径的左侧。文中选取了冷迹相对于台风路径出现在不同位置（左、右、附近）的4个台风为例来说明台风引起的降温特征。通过量化降温中心到台风路径的距离发现台风所引起的最大降温出现的位置主要集中分布在路径左右两侧100km范围内。另外，通过对比台风来之前的海平面高度距平发现先于台风之前处在于上层海洋环境的冷涡，特别是强冷涡，在台风引起的海表面降温幅度和位置分布中可能起着重要的作用，其中冷涡的位置与台风所引起的最大降温中心出现的位置有很好的相关性。 其次，本研究提出一个新的描述降温效应的指数。台风所经过的海域往往会出现海表温度的降低，而海表温度的变化对海洋生态系统有很重要的影响。台风的降温效应因台风、背景温度场和台风前的海洋环境条件而异。目前，海表温度对台风的响应效应主要是通过三个物理量来描述，降温幅度、冷迹范围、冷迹持续时间。但是还没有一个综合的量来对台风的降温效应进行定量的描述。本研究利用遥感微波SST数据尝试初步

南海北部区域表层水微生物多样性及其分布特点研究

海洋中的微生物多样性是十分丰富的。南海北部区域表层水的微生物群落结构及物种多样性情况仍不十分清楚。本研究，采用构建基因克隆文库的方法，对该区域内表层水中的微生物多样性及分布特点进行研究。获得了8000多个细菌16S rDNA基因、真核微生物ITS 区基因及光合微型生物 psbA 基因单克隆。本研究结果表明：在南海北部区域表层水中存在两种不同微生物类群，即近海岸带海洋微生物类群和开阔海域海洋微生物类群。 16S rDNA基因克隆文库中，确定了507个OTUs。93.7% 的16S rDNA 序列定义在同一种水平上，1.4 %的16S rDNA序列定义在同一属的水平上，2.7%的16S rDNA序列定义在同一纲的水平上，1.2%的16S rDNA序列定义在同一门的水平上。值得一提的是有0.7%的南海表层水样品的16S rDNA 序列，属于目前数据库中的未知序列。系统育树分析表明这类序列可归属于4个不同的分枝群。与Venter’s Sorcerer II 海洋科考（马尾岛海域）的结果不同，南海北部区域表层水中，并没有发现SAR11分支细菌、丝状杆菌（Fibrobacter）和Rheinheimera细菌序列，但南海北部区域却发现了马尾岛海域未检测到的物种，如酸杆菌门、恐球菌-栖热菌门、厚壁菌门，硝化螺旋菌门，浮霉菌门以及疣微菌类细菌。除疣微菌外，其他5种细菌都是海洋环境样品中较为常见的细菌。变形菌门、蓝细菌及厚壁菌门细菌序列是南海北部表层样品16S rDNA基因克隆文库中的主要类群。 真核生物如浮游植物和海洋真菌是海洋表面生物质的主要组成部分之一。现有的研究多集中在环境样品的原核微生物的群落结构研究上，很少关注海洋微型真核生物的多样性及群落结构分布。本研究通过构建ITS基因克隆文库的方法，得到了3044条ITS序列，最终定义了1288个OTUs。其中，329个OTUs序列定义在同一种水平上，310个OTUs序列定义在同一属或纲的水平上，123个OTUs序列定义在同一门的水平上。值得注意的是有339个OTUs的序列，属于目前数据库中的未知序列。系统发育树分析表明它们分别归属于4个不同的分枝群。这表明以往对海洋真核微型生物的多样性仍知之甚少。盘菌亚门、体腔动物门和担子菌纲是南海北部表层样品ITS基因克隆文库中的主要类群。此外，在南海北部区域还发现了少数归属于绿藻、链形植物、定鞭金藻类、放射虫类、Stramenopiles、Typhlocoela、壶菌类、多孢囊霉目、子囊菌门、地位未定的物种、 酵母、领鞭毛虫门、不可培养的后生动物和海绵动物的ITS序列。 海洋初级生产力主要是依靠光合微型浮游生物进行光合作用完成的。利用新设计的psbA通用引物，对南海北部33个表层水样滤膜进行基因克隆文库建库分析，最终获得了南海北部区域表层水微生物多样性及其分布特点研究3062条部分psbA基因序列，并将其划分为957个 OTUs。其中蓝细菌和未培养的病毒序列在psbA基因库中的数量最多。本研究还发现了南海北部区域存在11个独立分支的新型psbA类群。研究证实psbA基因可以作为一种研究海洋光合微型浮游生物群落结构的指示基因。 克隆文库相似性分析发现，在所有的16S rDNA克隆文库中没有任意两个站点的克隆文库相似性超过50%。虽然N401和N420站点的16S rDNA克隆文库相似性最大，但它们在地理位置上并不接近。一些地理位置接近的站点，其16S rDNA克隆文库之间相似性比较接近。比如，海南岛区域的克隆文库之间就比较相似，且在同一分支。大多数地理环境相似的站点的16S rDNA克隆文库都聚在同一大分支上。例如，来自于珠江口区域站点的克隆文库之间的相似性比较接近，而且分布在一个大分支中；开阔海洋区域的16S rDNA克隆文库，也大多聚类在同一分支中。但也有例外的情况：比如 N107 和N400 站点的16S rDNA克隆文库，就聚类到一起，分析发现这两个文库中所处的环境都是甲烷产生区，其中都含有相似的与甲烷代谢相关的菌群。不过从整体来看，整个南海北部的细菌群落，大致分为两大类：中国大陆近海岸微生物群落和开阔海域微生物群落。33个ITS克隆文库的相似性分析发现：相似性在10%以下的类群，可以分成两大分支，而且该分类，比细菌群落的分布情况更接近南海北部的地理环境特征。对psbA基因克隆文库的相似性分析也验证了在南海北部区域表层水中存在两种不同微生物生态系统。 此外，本研究针对分子生态专业软件DOTUR程序在处理大量克隆文库数据时所遇到的

The methane hydrate formation and the resource estimate resulting from free gas migration in seeping seafloor hydrate stability zone

It is a typical multiphase flow process for hydrate formation in seeping seafloor sediments. Free gas can not only be present but also take part in formation of hydrate. The volume fraction of free gas in local pore of hydrate stable zone (HSZ) influences the formation of hydrate in seeping seafloor area, and methane flux determines the abundance and resource of hydrate-bearing reservoirs. In this paper, a multiphase flow model including water (dissolved methane and salt)-free gas hydrate has been established to describe this kind of flow-transfer-reaction process where there exists a large scale of free gas migration and transform in seafloor pore. In the order of three different scenarios, the conversions among permeability, capillary pressure, phase saturations and salinity along with the formation of hydrate have been deducted. Furthermore, the influence of four sorts of free gas saturations and three classes of methane fluxes on hydrate formation and the resource has also been analyzed and compared. Based on the rules drawn from the simulation, and combined information gotten from drills in field, the methane hydrate(MH) formation in Shenhu area of South China Sea has been forecasted. It has been speculated that there may breed a moderate methane flux below this seafloor HSZ. If the flux is about 0.5 kg m-2 a-1, then it will go on to evolve about 2700 ka until the hydrate saturation in pore will arrive its peak (about 75%). Approximately 1.47 109 m3 MH has been reckoned in this marine basin finally, is about 13 times over preliminary estimate.

中国南海深海沉积物中的微生物资源

由于采样条件和培养条件的限制，深海微生物研究的较少，因此目前海洋微生物资源的研究主要集中在近海和浅海。而深海独特的生态环境，使微生物形成了独特的代谢体系，成为新颖化合物的重要来源，具有很好的开发应用前景。本文首次较为系统的研究了深度为1758-3600m南海海底沉积物中深海微生物资源的分离和活性菌株的筛选情况，旨在为探索我国南海深海微生物资源提供一定的科学依据。 采用多种分离培养基从6个不同深度（1758、2620、3200、3500、3587和3600m）的南海深海沉积物样品中，分离到225株深海微生物，包括40株放线菌和185株细菌。以分离得到的225株深海微生物为研究对象，从产蛋白酶、抗真菌、杀虫三个方面进行活性菌株的筛选，研究南海深海沉积物中的微生物资源状况： （1）.将分离到的225株深海微生物，同时在10℃、28℃、45℃三个温度下进行产低温蛋白酶、中温蛋白酶、高温蛋白酶的筛选。初筛结果表明：这225株深海微生物大都有大小不同的产蛋白酶能力。10℃有产蛋白酶的有109株，28 ℃产蛋白酶的有160株，45℃产蛋白酶的有117株。筛选到一株在45℃下有较强产蛋白酶能力的菌株B1394，其酶活可达873U/ml，有一定的应用前景。通过形态观察、生理生化测定、16SrDNA序列测定，将B1394定名为枯草芽孢杆菌（Bacillus subtilis）。其粗酶液性质研究发现：最适酶活温度60℃，最适pH 8.0， 40℃、50℃和60℃热稳定性较好， Mn2+ 、Mg2+ 、Ca2+对该蛋白酶有激活作用，Hg2+ 、Fe3+ 、Cu2+ 、Zn2+ 、 Fe2+对其有抑制作用，苯甲基磺酰氟（PMSF）几乎完全抑制其活性，推断为丝氨酸蛋白酶。 （2）.对其中100株深海细菌和40株深海放线菌，以立枯丝核菌（ Rhizoctonia solani）和白色念珠菌（Candida albicans）为靶菌进行了抗真菌活性的筛选。初筛结果表明：分别有37株和35株深海细菌对立枯丝核菌和白色念珠菌有抑菌活性，分别占被检测细菌数目的37%和35%；有18株深海放线菌对立枯丝核菌有抑制作用，占被检测放线菌总数的45%。筛选到一株有较强抗真菌活性的深海放线菌SHA6，其发酵液对包括尖孢镰刀菌（Fusarium oxysporum）在内的10种植物病原菌有明显的抑制作用。对其发酵液的理化性质进行初步研究发现SHA6发酵液具有良好的热稳定性和酸碱稳定性, 对SHA6进行分子生物学鉴定后将其初步定名为为橙色单胞菌（Aurantimonas altamirensis）。 （3）.以卤虫为初步筛选模型，对其中的20株深海放线菌进行了杀虫方面的筛选，结果发现有5个深海放线菌菌株表现有较强的杀虫活性。其中深海放线菌SHA4发酵液的乙酸乙脂提取物杀卤虫的活性最强，在浓度为100μg/ml时杀卤虫活性为83%,而在浓度400ppm时，48h可以杀死38%的甜菜夜娥。对SHA4进行分子生物学鉴定后将其初步定为拟诺卡氏菌属（Nocardiopsis sp）。 总之，本论文阐明了我国南海深海沉积物中微生物资源状况的初步研究结果，为进一步开发利用我国南海深海微生物资源奠定了基础。

Optimizing the formation of in vitro sponge primmorphs from the Chinese sponge Stylotella agminata (Ridley)

The establishment and optimization of in vitro primmorph formation from a Chinese sponge, Stylotella agminata (Ridley), collected from the South China Sea, were investigated. Our aims were to identify the key factors affecting primmorph formation in this species and to optimize the technique for developing an in vitro primmorph culture system. The size of dissociated cells from S. agminata is relatively small, in the range between 5 and 10 mum. Round-shaped primmorphs of less than 100 gm were formed 3 days after transferring the dissociated cells into seawater containing Ca2+ and Mg2+. The effect of various cell dissociation conditions, inoculum. cell density, concentration of antibiotics, pH, and temperature was further investigated upon the formation of primmorphs. The time required for primmorph formation, primmorph size distribution, and the proliferating capability were microscopically documented. Healthy sponge S. agminata, inoculum. cell density and culture temperature play a critical role for the successful formation of primmorphs and that the microbial contamination will have to be controlled. (C) 2002 Elsevier Science B.V. All rights reserved.

Web-based spatiotemporal visualization of marine environment data

With long-term marine surveys and research, and especially with the development of new marine environment monitoring technologies, prodigious amounts of complex marine environmental data are generated, and continuously increase rapidly. Features of these data include massive volume, widespread distribution, multiple-sources, heterogeneous, multi-dimensional and dynamic in structure and time. The present study recommends an integrative visualization solution for these data, to enhance the visual display of data and data archives, and to develop a joint use of these data distributed among different organizations or communities. This study also analyses the web services technologies and defines the concept of the marine information gird, then focuses on the spatiotemporal visualization method and proposes a process-oriented spatiotemporal visualization method. We discuss how marine environmental data can be organized based on the spatiotemporal visualization method, and how organized data are represented for use with web services and stored in a reusable fashion. In addition, we provide an original visualization architecture that is integrative and based on the explored technologies. In the end, we propose a prototype system of marine environmental data of the South China Sea for visualizations of Argo floats, sea surface temperature fields, sea current fields, salinity, in-situ investigation data, and ocean stations. An integration visualization architecture is illustrated on the prototype system, which highlights the process-oriented temporal visualization method and demonstrates the benefit of the architecture and the methods described in this study.

Population genetic structure of crimson snapper Lutjanus erythropterus in East Asia, revealed by analysis of the mitochondrial control region

The population genetic structure of the crimson snapper Lutjanus erythropterus in East Asia was examined with a 427-bp hypervariable portion of the mtDNA control region. A total of 262 samples were collected and 75 haplotypes were obtained. Neutrality tests (Tajima's and Fu's) suggested that Lutjanus erythropterus in East Asia had experienced a bottleneck followed by population expansion since the late Pleistocene. Despite the low phylogeographic structures in mtDNA haplotypes, a hierarchical examination of populations in 11 localities from four geographical regions using analysis of molecular variance (AMOVA) indicated significant genetic differentiation among regions (Phi(CT) = 0.08564, p < 0.01). Limited gene flow between the eastern region (including a locality in the western Pacific Ocean and two localities in the East Sea) and three geographic regions of the South China Sea largely contributed to the genetic subdivision. However, comparisons among three geographic regions of the South China Sea showed little to no genetic difference. Populations of Lutjanus erythropterus in East Asia are inferred to be divided into two major groups: an eastern group, including populations of the western Pacific Ocean and the East Sea, and a South China Sea group, consisting of populations from northern Malaysia to South China. The results suggest that fishery management should reflect the genetic differentiation and diversity in East Asia. (c) 2006 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.