Pharmacological and immunocytochemical investigation of the role of catecholamines on larval metamorphosis by beta-adrenergic-like receptor in the bivalve Meretrix meretrix

Catecholamines regulate several physiological processes in mollusks. Many pharmacological experiments have been conducted to determine the effects of adrenergic agonist and antagonist of catecholamine receptors on Meretrix meretrix metamorphosis. Results showed that adrenaline (AD) and noradrenaline (NA) had substantial effects (p < 0.05) on larval metamorphosis at concentrations ranging from 10 mu M to 100 mu M. 10 mu M beta-adrenergic receptor (AR) agonist isoproterenol showed the same inducement effect as that of NA and AD on metamorphosis, whereas the alpha-AR agonist phenylephrine had no significant effect at concentrations between 0.1 mu M and 100 mu M concentrations (p > 0.05). Furthermore, I mu M beta-AR antagonist propanolol, but not alpha-AR antagonist prazosin, depressed the larval metamorphosis induced by NA or AD. By immunocytochemistry, two cell bodies of beta-adrenergic-like receptor, C/A1, C/A2, were observed in the cerebral/apical ganglion of competent larvae. In addition, there were other immunoreactive dots near C/A1 and C/A2. The results of pharmacology and immunocytochemistry suggests that beta-adrenergic-like receptor located in the larval CNS, might play a considerable role in the larval metamorphosis of M meretrix by AD or NA. (c) 2006 Elsevier B.V. All rights reserved.

Short-term morphological changes after sand-digging during a sand sculpture activity

The morphology of the beach backshore and foreshore at Huiquan Bay, Qingdao, China, is characterized by a single intertidal sandbar system with a spring tide range of 4.59 m. The beach was measured with a laser total station of Leica TPS402. Contours of the beach were generated using data collected in March and November 2005. The survey method provided 2 mm measuring accuracy and 4-10 m horizontal spacing. The net accretion volume of the foreshore was about 11, 215 m(3) from March to November. After sand sculpture activity, the axis of the sand trough migrated onshore from about 3.5 m to 17.5 m on the foreshore beach in November. At the same time, the axis of the sandbar crest migrated onshore no more than 42.25 m on the northwest foreshore; and it migrated offshore no more than 23.75 m on the southeast foreshore. On the northwest and southeast foreshore beach, two strips of erosion areas with a thickness of 0-0.2 m appeared on the sandbar crest. Accretion occurred at the bottom of the sand trough with a thickness of similar to 0.2-0.6 m. The sandbar height decreased after sand sculpture activity, and it was no more than 0.7 m in March and 0.6 m in November. Human activities, such as sand digging on the sandbar crest during sand sculpture activity, also can disturb the beach morphology of intertidal bar systems. This phenomenon also was validated by comparison of beach morphology, the results of a color artificial tracer experiment and a sediment transportation trend prediction.

Authigenic sulfide minerals and their sulfur isotopes in sediments of the northern continental slope of the South China Sea and their implications for methane flux and gas hydrate formation

This is a report of the study of the authigenic sulfide minerals and their sulfur isotopes in a sediment core (NH-1) collected on the northern continental slope of the South China Sea, where other geophysical and geochemical evidence seems to suggest gas hydrate formation in the sediments. The study has led to the findings: (1) the pyrite content in sediments was relatively high and its grain size relatively large compared with that in normal pelagic or hemipelagic sediments; (2) the shallowest depth of the acid volatile sulfide (AVS) content maximum was at 437.5 cm (> 2 mu mol/g), which was deeper than that of the authigenic pyrite content maximum (at 141.5-380.5 cm); (3) delta S-34 of authigenic pyrite was positive (maximum: +15 parts per thousand) at depth interval of 250-380 cm; (4) the positive delta S-34 coincided with pyrite enrichment. Compared with the results obtained from the Black Sea sediments by Jorgensen and coworkers, these observations indicated that at the NH-1 site, the depth of the sulfate-methane interface (SMI) would be or once was at about 437.5-547.5 cm and the relatively shallow SMI depth suggested high upward methane fluxes. This was in good agreement with the results obtained from pore water sulfate gradients and core head-space methane concentrations in sediment cores collected in the area. All available evidence suggested that methane gas hydrate formation may exist or may have existed in the underlying sediments.

Distribution and mobility of metals in agricultural soils near a copper smelter in South China

The distribution and mobility of heavy metals in the paddy soils surrounding a copper smelting plant in south China was investigated. We assessed the degree of metal contamination using an index of geoaccumulation. The metals were divided into two groups: (1) Cu, Zn, Pb and Cd, whose concentrations were heavily affected by anthropogenic inputs, and (2) Ni, Co and Cr, which were mainly of geochemical origin. Concentrations of Cu, Cd, Zn, and Pb in the polluted soils were higher than the Chinese soil quality criteria. The chemical partitioning patterns of Pb, Zn and Cu indicated that Pb was largely associated with the residual and NH2OH HCl extractable fractions. In contrast, Cd was predominantly associated with the MgCl2 extractable fraction. A large proportion of Cu was bound to the acidic H2O2 extractable fractions, while Zn was predominantly found in the residual phase. The fraction of mobile species, which potentially is the most harmful to the environment, was found to be elevated compared to unpolluted soils in which heavy metals are more strongly bound to the matrix. The mobility of the metals was studied by water extraction using a modification of Tessier's procedure, and the order of mobility was Zn > Cd > Cu > Ce > Pb.

An approach to prediction of the South China Sea summer monsoon onset

In the present paper, correlation between the South China Sea summer monsoon (SCSSM) onset and heat content in the upper layer of the warm pool in the western Pacific Ocean is examined using the Scripps Institution of Oceanography dataset for the period of 1955-1998 and an approach to prediction the SCSSM onset is proposed. Correlation showes that there exists interdecadal variability of the SCSSM onset demarcated by 1970 with the largest correlation coefficient in the area west of the center of the warm pool rather than near its centers, implying certain effect from other factors involved besides ENSO. As the correlation is poor for the period before 1970, the heat content anomaly of the warm pool after 1970 is used to indicate early or late onset of the SCSSM beforehand. An ideal representative area (1A degrees x1A degrees) for the warm pool heat content was determined with its center at 3A degrees N/138A degrees E. The nearest TAO (TAO-Tropical Atmosphere Ocean-array) mooring to the center is at 2A degrees N/137A degrees E, and chosen to calculate the heat content for prediction. It is suggested that the TAO mooring at 2A degrees N/137A degrees E could be used to predict the SCSSM onset with the heat content in the upper layer, if the correlation between the SCSSM onset and the heat content of the warm pool runs like that of after 1970. On the other hand, if the situation does like the one before 1970, the representative station is determined at 13A degrees S/74A degrees E with relatively poor correlation, meaning that the warm pool in the western Pacific Ocean plays more important role in the SCSSM onset than the Indian Ocean.

近海面气象参数的反演及应用研究

全球气候与人类活动密切相关，气候研究一直是现代科学家关注的重点问题之一。过去海面气象参数的研究主要借助于浮标和站点的观测，但是它们稀少的观测资料极大地限制了海面气象参数的研究。现在借助卫星观测大大地提高我们的认识能力，卫星可以对全球海洋进行连续观测，获取长期大范围的海洋气象资料，为全面深入地了解大洋甚至全球大气活动提供可能。 本文的工作就是利用卫星资料进行月平均和实时的近海面气象参数的反演及应用研究。利用近十八年SSM/I和AVHRR卫星资料与实测资料进行结合，建立神经网络（ANN）模型反演近海面月平均气温和湿度，与实测资料相比气温的均方根差为0.87 ℃，相关系数为 0.99，相对湿度的均方根差为3.73%，相关性为0.65。利用同步物理方法从TOVS资料反演中国海区上空1000mb到10mb之间的温湿廓线，再利用神经网络方法和基于Bowen比的方法从温湿廓线的结果反演出近海面处的实时气温和露温参数，取得了比较合理的结果，气温和露温结果的均方根差分别是1.85K和2.59K（与实测数据相比）。利用2005年1月的AMSR-E亮温资料对实时气象参数反演进行探讨，分析AMSR-E的各个探测通道与海表温度、近海面气温、湿度和风速等参数的相关性，把12个通道分为四种情况并在每种情况下分别进行试验，选择最合适的组合通道并进行气象参数的反演，结果与TAO资料进行比较，海表温度的均方根差是0.55℃，近海面气温的均方根差是0.74℃，海面湿度的均方根差是3.24%，海面风速的均方根差是1.11m/s。目前，与其它结果相比该结果的精度是最好的。 把以上反演得到的近海面气象参数结果应用于海气界面热通量的计算，以更好地研究海气相互作用。分别采用神经网络和Bulk公式两种方法计算月平均潜热和感热通量，结果与GSSTF2资料进行比较，Bulk方法反演的感热和潜热的均方根差分别为9.05±4.6 W/m2和23.7±4.0 W/m2，ANN模型得到的分别是7.54±3.0 W/m2和20.1±3.2 W/m2，，结果表明ANN模型得到的结果明显的好于Bulk公式。ANN模型反演的全球潜热和感热结果在空间分布上与GSSTF2的吻合很好，但在极大值区，ANN模型得到的结果偏小。把AMSR-E亮温资料反演得到的实时的海表温度、近海面气温、湿度和风速四个参数结合ANN模型，计算太平洋赤道地区的实时感热和潜热通量。 对反演得到的约18年近海面月平均气温进行年变化分析,得知近18年里气温呈现上升趋势。近海面气温在反映气候异常信息上有与海表温度相似的表达性，1989冷事件年，全球平均海面气温明显偏低（14.25℃），1998暖事件年，平均海面气温值最大（14.57℃ ）。用经验正交函数（EOF）和经验模态分解（EMD）分析近海面气温的距平变化，得到的前三个主要模态解释了84%的总体变化，EOF1解释了76.1%的变化，主要表达了太阳辐射引起的年周期气温变化；EOF2解释了4.6%的变化，主要解释ENSO对气温异常的作用；EOF3（3.3%）的空间模态呈现了很多有趣的现象，比如气温正异常主要表现在北半球的高纬度区，南极附近高低起伏的气温异常可以作为南极绕极流的一个证据等。

热带太平洋次表层海温变化及其与ENSO循环的研究

随着全球变暖和各种极端天气事件发生频率的增加，气候变化已成为全世界关注的焦点问题，ENSO事件是年际尺度上气候变化的最强信号，它的影响波及到世界各地，所以，对ENSO事件进行深入研究，弄清其发生机制，具有重要的科学意义。虽然，目前对ENSO事件的研究已经取得了巨大成果，但仍不能对其发生发展的全过程进行准确的预测，因此，仍需要对其进行深入研究，本文正是从热带太平洋次表层温度场和流场的变化着手，对ENSO循环过程中的相关机理进行研究。 通过对TOGA/TAO、SODA和NCEP等海洋大气实测和再分析资料的分析，研究了热带太平洋次表层海温和流场的变化特征，分析了它们的变化机理，进而深入探讨了它们与ENSO事件的相互关系，并利用全球海洋数值模式的敏感性试验，探讨了大气风场的变化对海洋次表层要素的影响，主要得到以下结论： 1. 上世纪70年代末的气候突变之后，用28℃定义西太平洋暖池（WPWP），已不能合理的描述WPWP的基本特征。我们通过对比分析提出，用28.5℃来定义WPWP更合理，这一定义即可以充分反映WPWP突变前的特征，又能够合理的反映WPWP突变后的特征；对新定义的WPWP区域不同深度的海温距平的分析表明，次表层（148m）海温距平的变化趋势和变化幅度与表层和深层的变化差异较大，次表层海温的变化幅度最大并且年代际变化趋势与上下层正好相反；进一步的研究表明，WPWP次表层海温的年代际变化与PDO的变化有一定关系。 2. 利用热带太平洋次表层海温的变化特征，定义了表征ENSO事件的新指数——赤道太平洋温跃层海温振荡指数（EPOI），与其它ENSO指数相比，EPOI将东、西太平洋次表层海温的变化信息都包括在内，能够较全面的反映出ENSO事件的变化特征，特别是EPOI可以较好的反映出ENSO循环的年代际变化特征。另外，EPOI的变化比ONI的变化超前2个月，更有利于对ENSO事件的提前预报。由于EPOI主要反映海洋次表层的变化特征，因此能够更好的满足对ENSO机理研究的需要。 3. 赤道潜流距平场的EOF分析表明，其前两个模态的方差贡献较大，第一模态方差贡献为30.75%，主要反映东太平洋赤道潜流的变化特征；第二模态方差贡献为16.18%，主要反映中太平洋赤道潜流的变化特征。赤道潜流前两个模态与ENSO指数的变化有很好的相关关系，其中东太平洋潜流在滞后ENSO指数1个月时，二者达到最大负相关（r=-0.74）。中太平洋赤道潜流的变化对“东部型”和“中部型”El Niño事件的形成有一定影响。“东部型”El Niño事件发生前，中太平洋赤道潜流异常增强，次表层异常海温信号随着潜流中心迅速向东移动到达东太平洋，使得“东部型”El Niño事件爆发；而“中部型”El Niño事件发生前，中太平洋赤道潜流则异常减弱，西太平洋异常海温信号不能迅速向东传播，而是在中西太平洋堆积并向上扩展，使得异常海温首先在中太平洋出现，“中部型”El Niño事件爆发。 4. ENSO循环过程中，异常冷（暖）信号之所以在8ºN-10ºN附近向西传播的原因较多，其中温跃层深度在8ºN-10ºN的特殊分布特征对其有一定贡献，具体表现为在北半球8ºN-10ºN正好是温跃层深度较浅的区域，该区域的温跃层相当于从东到西的一个海下“山脊”，使得来自南北两侧的异常信号都很难穿过这一区域，而只能沿该纬度向西传播；而南半球的温跃层对来自赤道地区的异常信号没有阻挡作用，使其可以直接传播到高纬度地区。ENSO信号的强度在传播过程中发生了明显的变化，主要是ENSO事件爆发后，4-5年的周期信号并没有传到东太平洋10ºN附近，在从东到西的传播过程中，4-5年的周期信号有所增加，但增加的幅度较小。在西太平洋有来自南、北半球中高纬度异常信号的补充，从而使得ENSO循环得以维持。 5. 数值模拟表明，不同区域风应力的变化对海洋的影响各不相同。赤道地区风应力对海洋的影响主要通过纬向分量的变化来产生作用，它的变化主要对赤道次表层海温的变化产生影响，并且东西太平洋呈现反位相变化趋势；而对流场的影响则是上下层反位相变化。北太平洋副热带地区风应力的变化对海洋的影响与赤道有明显不同，对温度场的影响表现为东西太平洋次表层海温的变化一致，而对流速的影响则是东西太平洋反位相变化。

AMSR-E卫星海面气象参数遥感方法研究

全球气候变化对人类社会有重要影响，气候变化已经成为当今科学界、各国政府和社会公众普遍关注的环境问题之一，它可能对生态系统和社会经济产生灾难性的影响。海洋约占着地球表面70%的面积，海洋的变化对全球气候的变化起着非常重要的作用，海面气象参数的研究也成为关注的重点之一。卫星遥感技术的发展，为海洋科学提供了广阔的发展空间。通过卫星可以对全球海洋进行连续观测，能够获取长期的大范围的海洋气象资料，进而可以比较全面而深入的研究全球海洋及大气。 本文的主要工作就是利用AMSR-E卫星资料进行瞬时和月平均近海面气象参数反演。利用遗传算法，根据2002年6月-2006年12月的AMSR-E的瞬时海洋产品数据与TAO和NDBC实测数据，反演瞬时近海面气温和比湿，与实测资料相比瞬时近海面气温和比湿的均方根误差分别1.13℃，1.28 g/ kg。根据2002年7月-2007年12月的AMSR-E月平均数据与实测资料，反演月平均近海面气温和比湿，同实测资料相比，均方根误差分别为0.80℃，1.03k/kg。将遗传算法反演的结果同神经网络和线性回归方法进行比较，遗传算法可以较好的反演近海面气象参数，且遗传算法具有客观性和数据适应性，可以不依赖于导数信息或其他辅助信息来进行最优种搜索。并利用2005年一年的AMSR-E位于赤道太平洋区域亮温资料反演近海面气温和比湿，结果同TAO资料进行比较，均方根误差分别为0.71℃和0.91g/kg。

西太平洋—印度洋—青藏高原气候系统在南海夏季风爆发过程中的作用

本文利用美国国家环境预测中心和国家大气研究中心(NCEP/NCAR—National Centers for Environmental Prediction/National Center for Atmospheric Research)的位势高度、气温、风速等大气资料、欧洲中期天气预报中心 （ECMWF—European Centre for Medium-Range Weather Forecasts—ERA-40）的雪深资料、美国国家海洋大气管理局（NOAA—National Oceanic and Atmospheric Administration）的海表温度（SST）资料、美国Scripps海洋研究所的上层海洋热含量资料等，采取相关分析、合成分析、经验正交函数分析、小波分析和小波交叉谱分析等统计分析方法，系统深入地讨论了西太平洋—印度洋—青藏高原气候系统在南海夏季风爆发过程中的作用。得到的主要结论如下： 1. 西太平洋和印度洋在南海夏季风爆发过程中起着关键作用 利用1951－1998年多种大气海洋资料，分析研究结果表明，西太平洋（暖池热含量）、印度洋（纬向风）在南海夏季风爆发中起关键的调控作用：以1970年为界，1970年之前，印度洋起主要作用，1970年之后西太平洋起主要作用，这主要是1970前后北极涛动有明显跃变的原因，这种跃变决定了印度洋在南海夏季风爆发中是否起决定作用（西风异常或东风异常），进而，决定了有利于或不利于南海夏季风的爆发。 1970年之前，北极涛动指数为负值，海陆温差（海上气温减大陆气温）是负值，大陆气温偏高，印度洋气温相对偏低，印度洋出现西风异常，有利于南海夏季风早爆发。在此期间，与印度洋SST密切相关的南印度洋偶极子的变化也与南海夏季风的爆发紧密相联。当南印度洋为正偶极子（西南印度洋SST为正异常，印度洋其他区域的SST为负异常）时，北印度洋为西风异常，南海夏季风爆发偏早；南印度洋为负偶极子（西南印度洋SST为负异常，印度洋其他地区的SST为正异常）时，北印度洋为东风异常，南海夏季风爆发偏晚。 1970年之后，北极涛动指数为正值，海陆气温差为正值，印度洋的状态不利于南海季风爆发；在这种情况下，西太平洋暖池的热含量则成为控制南海夏季风爆发的主要原因：暖池变暖的年份，即 La Niña 年，南海夏季风爆发早（强），反之，当暖池变冷的年份，即El Niño年，南海季风爆发晚（弱），即，南海夏季风爆发的早（强）晚（弱）与ENSO事件密切相关。 2.青藏高原春季积雪对南海夏季风爆发有重要的影响 1958-2003年青藏高原3月积雪厚度与南海夏季风爆发时间存在着很好的正相关。青藏高原3月积雪厚度偏厚时，其500毫巴以上的气温偏低，上层海陆之间的气温差是正值，南亚高压向西北方向的移动速度变慢，上层东风偏弱，西太平洋地区的上层辐散和下层辐合变弱，西太平洋暖池热含量偏少，南海夏季风爆发偏晚（弱）。同时，下层850毫巴东印度洋异常大气是东风和跨赤道反气旋对，南海被东风异常所控制，这种大气环流形势不利于南海夏季风的爆发；青藏高原3月积雪厚度偏薄时，其500毫巴以上的气温偏高，上层海陆之间的气温差是负值，上层南亚高压在南亚地区建立较早，上层东风偏强，西太平洋地区的上层辐散和下层辐合偏强，西太平洋暖池热含量偏多，南海夏季风爆发偏早（强）。同时，下层850毫巴东印度洋低层大气是西风异常和跨赤道气旋对，南海被西南风异常所控制，有利于南海夏季风的爆发。 研究结果还表明，青藏高原春季的积雪与厄尔尼诺事件存在着密切的关系。在厄尔尼诺鼎盛期的冬季，各种条件都有利于青藏高原的降雪，从而，来年春天的积雪则变厚，不利于南海季风的爆发。 3. 南海夏季风爆发的预测 1970年之后，西太平洋暖池的热含量与南海夏季风的爆发早晚有非常好的负相关。据此，我们可以通过西太平洋暖池热含量的变化来预测南海夏季风的爆发。通过暖池区海洋上层400米热含量的分析研究，我们找到了西太平洋暖池热含量变化的代表站点（以3N，138E为中心的1°×1°范围），其热含量变化能很好代表整个西太平洋暖池热含量的变化（相关系数大于0.85）。在此基础上，文章用1993-2007年热带大气海洋浮标列阵（TAO-Tropical Atmosphere Ocean-array）中最靠近该站点的浮标（2N, 137E）资料验证了上述选择站点的代表性和相应的预测能力。1993-2004年TAO浮标（2N, 137E）3月上层400米和500米海洋热含量与南海夏季风爆发时间的相关系数分别是-0.75，-0.73，置信度均超过99%；用1993-2007年4月份TAO浮标（2N, 137E）上层400米和500米海洋热含量与南海夏季风爆发时间作相关则相关系数均为-0.83，置信度超过99%。因此，我们可以通过3月或者4月份该TAO浮标（2N, 137E）的热含量来预测当年南海夏季风爆发的早（强）晚（弱）。 总之，南海夏季风爆发以1970年为界存在明显的年代际变化，1970年之前，主要受印度洋控制，1970年之后，南海夏季风爆发主要受控于太平洋（西太平洋暖池），这种变化是由北极涛动年代际变化引起的，。青藏高原春季积雪也对南海夏季风有重要影响，但主要受ENSO控制。因此，我们认为西太平洋—印度洋—青藏高原气候系统在南海夏季风爆发中起着重要的调控作用：西太平洋的作用当属第一位，印度洋的作用居第二，青藏高原的作用最弱。

Effects of single and mixed diatom diets on the reproduction of copepod Calanus sinicus

Under laboratory conditions, the potential influence of diatom diets on reproduction of zoo-plankton Calanus sinicus was studied. Four diatom diet ingredients: Skeletonema costatum (SC), Chaetoceros muelleri (CM), Phaeodactylum tricornutum (PT), diatom mixture (MIX) and a control diet: the flagellate Platymonas subordiformis (PS), were used at the same carbon concentrations of 2.0 mu g mL(-1) C. In a period of 17-day laboratory experiment, the effects of these algae diets on egg production and hatching success of the copepod Calanus sinicus were examined. The diets were analyzed for fatty acid content as an indicator of food quality. The results showed that the female survival of all treatments reached more than 80% except PT. Comparing to the initial value, egg production of Calanus sinicus was reduced in diatom diets (PT, CM), but remained in normal level in SC and MIX, indicating that some single diatom diets had a negative effect on the egg production of Calanus sinicus. Feeding with mixed food however can eliminate this negative effect. Among all the treatments, hatching success in filtered seawater was significantly higher than in algal exudates, indicating that not only diatoms but also other phytoplankton in certain concentration can release extracelluar substance that may inhibit eggs from hatching. Fatty acid analysis showed that both egg production rate and hatching success were negatively correlated to the ratio of 20:5 omega 3 and 14:0 in fatty acid composition.

Characterization of a homogeneous taxonomic group of marine magnetotactic cocci within a low tide zone in the China Sea

Magnetotactic bacteria are a heterologous group of motile prokaryotes, ubiquitous in aquatic habitats and cosmopolitan in distribution. Here, we studied the diversity of magnetotactic bacteria in a seawater pond within an intertidal zone at Huiquan Bay in the China Sea. The pond is composed of a permanently submerged part and a low tide subregion. The magnetotactic bacteria collected from the permanently submerged part display diversity in morphology and taxonomy. In contrast, we found a virtually homogenous population of ovoid-coccoid magnetotactic bacteria in the low tide subregion of the pond. They were bilophotrichously flagellated and exhibited polar magnetotactic behaviour. Almost all cells contained two chains of magnetosomes composed of magnetite crystals. Intriguingly, the combination of restriction fragment length polymorphism analysis (RFLP) and sequencing of cloned 16S rDNA genes from the low tide subregion samples as well as fluorescence in situ hybridization (FISH) revealed the presence of a homogenous population. Moreover, phylogenetic analysis indicated that the Qingdao Huiquan low tide magnetotactic bacteria belong to a new genus affiliated with the alpha-subclass of Proteobacteria. This finding suggests the adaptation of the magnetotactic bacterial population to the marine tide.

Summer reproduction of the planktonic copepod Calanus sinicus in the Yellow Sea: influences of high surface temperature and cold bottom water

We have observed that Calanus sinicus retreated from neritic areas in the Yellow Sea and concentrated in the Yellow Sea Cold Bottom Water (YSCBW) area in summer. To investigate the summer reproductive strategy of C. sinicus in this situation, effects of high temperature on reproduction and hatching, as well as geographical variation of in situ egg production rate, were studied by onboard incubation in August 2001. Diel vertical migration (DVM) of females was investigated within and outside the YSCBW, respectively. Onboard incubation at 27 degrees C (i.e. surface temperature) resulted in lower fecundities than that at 9.8 and 12 degrees C (i.e. bottom temperature inside and outside the YSCBW) together with decreased hatching rates and increased naupliar malformation. Egg production was more active at stations outside the YSCBW than inside, where chlorophyll-a concentration was also relatively low. Females inside the YSCBW underwent DVM although they rarely entered the surface layer, but DVM was not observed outside the YSCBW. We conclude that surface temperature in summer has deleterious effects on C. sinicus egg production and hatching, and that it cannot reproduce successfully over the whole area. Inside the YSCBW, egg production is depressed by low food availability, while females outside suffer from high temperatures because of strong vertical mixing.

Fluorescence Characterization of Dissolved Organic Matter in East China Sea

Sea water samples were collected in the East China Sea in March and April, 2005, and three-dimensional fluorescence of dissolved organic matter was measured by fluorescence excitation-emission matrix spectroscopy. The position, number and intensity of fluorescence peak in the spectra and the relations of the peaks were analyzed to determine the type, distribution and origin of the fluorescence dissolved organic matter. Seven types of fluorescence peaks were detected from the samples. There are protein-like fluorescence peaks B with Ex(max)/Em(max) = 275/300 nm, D with Ex(max)/Em(max) = 225/295-305 nm, T with Ex(max)/Em(max) = 280/345 nm, and S with Ex(max)/Em(max) = 225-240/320-350 nm, two humic-like peaks A with Ex(max)/Em(max) = 250-255/410-455 nm and C 335-345/410-440 ran, and marine humic peak M with Ex(max)/Em(max) = 305 nm/400-420 nm. Peaks B, S and A appeared in all surveyed area. Peaks T and D appeared in the north of the surveyed area. Peaks M and C only appeared in a few stations. In the surface layer, the source of the fluorescence dissolved organic matter might be the fresh water outflow of the Yangtze River, while the fluorescence dissolved organic matter in the middle layer had double sources from the Yangtze River and the phytoplankton. The good correlationships of different fluorescence peaks showed the same source or some relationship between the protein-like and the humic-like fluorescence dissolved organic matter.

INVOLVEMENT OF CA(2+) SIGNALING PATHWAY DURING OOCYTE MATURATION OF THE NORTHERN QUAHOG MERCENARIA MERCENARIA

In many molluses, it has been found that Ca2+ signaling pathway is involved in the resumption of meiotic maturation in oocytes. To better understand the possible role of Ca2+ signaling pathway in regulating meiotic maturation in oocytes of the northern quahog Mercenaria mercenaria, free extracellular Ca2+, A23187 (calcium ionophore), verapamil (calcium channel blocker), and trifluoperazin (calmodulin antagonist) were used to incubate oocytes or serotonin-induced oocytes by pharmacological methods. Results show that extracellular Ca2+ (50 similar to 200 mM) and A23187 (1 similar to 10 mu M) can stimulate the meiotic maturation. In addition, verapamil (1 similar to 100 mu M) and trifluoperazin (10 similar to 1,000 mu M) could inhibit serotonin-induced oocyte maturation. Therefore, Ca2+ is essential for the reinitiation of meiotic maturation in oocytes of the northern quahog. Moreover, an increase i [Ca2+]i can promote meiotic maturation.

Onshore-offshore variations of copepod community in northern South China Sea

Copepod communities in onshore and offshore waters show a gradient from primarily near shore to primarily oceanic species. Understanding the transition between these communities is fundamental to determining the range of coastal influence. Copepod communities in the northern South China Sea (nSCS) were studied based on samples collected by vertically towing a net in 10 February-6 March (winter) and 26 August-6 September (summer) of 2004. Calanoida species richness, total copepod abundance, Shannon-Weaver diversity index, and onshore-offshore occurrence of dominant species showed obvious change from onshore to offshore waters. Although the offshore stations had lower abundance than the shelf stations, they had more species and larger diversity index. Abundance of some species (groups) with dominance index > 5% (Calanus sinicus, Euchaeta spp., Temora spp., Paracalanus parvus, and Subeucalanus subtenuis) declined from onshore to offshore waters. Warm water species (Pleuromamma abdominalis, P. gracilis, and P. robusta) occurred in offshore waters in both cruises. Station (q-type) cluster analysis in winter and summer separated copepod community into onshore and offshore communities at similar to 40% level of similarity. The two communities were divided at the position of similar to 100-m isobath. In summer, C. sinicus occurred in the upwelling area east of Hainan Island, indicating the presence of an oversummering stock of this species.