Effects of salinity, temperature and food type on the uptake and elimination rates of cd, cr, and zn in the asiatic clamcorbicula fluminea

Laboratory radiotracer experiments were conducted to determine assimilation efficiencies (AE) from ingested algal food and oxic sediment particles, uptake rates from the dissolved phase, and the efflux rates of Cd, Cr and Zn in the Asiatic clamCorbicula fluminea. Among three elements, AE from both algal and sediment food was greatest for Cd, followed by Zn and Cr. The AEs of tested elements from algal food(Phaeodactylum tricornutum) were consistently higher than those from sediments at a given salinity and temperature. The influence of salinity (0, 4 and 8 psu) and temperature (5, 13 and 21¼) on the metal AEs was not evident for most tested elements, except Cd AEs from sediment. The rate constant of metal uptake from the dissolved phase (k _u was greatest for Cd, followed by Zn and Cr in freshwater media. However, in saline water, thek _u of Zn were greater than those of Cd. The influx rate of all tested metals increased with temperature. The efflux rate constant was greatest for Cr (0.02 d^-1), followed by Zn (0.010~0.017 d^-1) and Cd (0.006 d^-1). The efflux rate constant for Zn in clam tissues depurated in 0 psu (0.017 d^-1) was faster than that in 8 psu (0.010 d^-1). Overall results showed that the variation of salinity and temperature in estuarine systems can considerably influence the metal bioaccumulation potential in the estuarine clamC. fluminea. The relatively high Cd accumulation capacity ofC. fluminea characterized by the high AE, high dissolved influx rate and low efflux rate, suggested that this clam species can be used as an efficient biomonitor for the Cd contamination in freshwater and estuarine environments.     

Cloning of cytochrome P450 1A (CYP1A) genes from the hermaphrodite fish Rivulus marmoratus and the Japanese medaka Oryzias latipes

To use two small fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae) and the Japanese medaka Oryzias latipes (Belloniformes) as testing models in molecular ecotoxicology, we have cloned the cytochrome P450 1A (CYP1A) gene after screening of both genomic DNA libraries, and sequenced 11,863 and 7,243 bp including all the exons and introns with promoter regions, respectively. The Rivulus and the medaka CYP1A gene consisted of seven exons (including non-coding exons) with high homology to mammals. In the promoter region, Rivulus CYP1A gene has seven xenobiotic response elements (XREs) and two metal response elements (MREs), while the Japanese medaka CYP1A gene has six XREs and four MREs. Interestingly, medaka CYP1A gene has a number of MREs at the promoter, which may affect its response on metal exposure. We describe here the gene structure of both fish CYP1A genes.     

深圳发展东部滨海旅游度假区的前景探析

深圳具备优良的海滨旅游资源，但其滨海旅游特色一直体现得不够充分，滨海度假旅游品牌在全国以至海外的影响力还很有限。深圳最近对东部滨海地区的发展进行了总体规划，根据深圳东部滨海地区发展现状和发展规划，就开发深圳东部滨海旅游度假胜地、将东部滨海旅游度假区打造成为具有国际水准的、以滨海休闲度假为特色的黄金海岸旅游胜地提出了的几点建议。     

基于GIS的柘林湾生态信息系统

柘林湾生态信息系统以ArcGIS为开发平台，采用客户端／服务器的体系结构，基于ArcObjects的组件式二次开发而成，实现了柘林湾的三维实景模拟、生态数学模型与GIS的有效集成、分析评价结果与地理空间数据相结合等功能，具有可视化、智能化、易扩展、安全实用等特点．该系统的建成．极大地提高了柘林湾生态信息的现代化管理水平，并为制定柘林湾的污染防治与生态环境保护策略提供了强有力的支持．     

南海季风型海-气耦合模态的时空特征及其与中国夏季降水的关系

使用NCEP/NCAR的海表温度(SST)、海面10 m风场的月平均再分析资料,用联合SVD(CSVD)的方法研究了不同季节南海的海气耦合模的时空分布特征及其与中国夏季降水的关系。通过对不同季节的海-气耦合模的年际变化特征的分析。结果发现:第一模态为最显著模态,模态协方差贡献比在四季均超过80%,空间上SST表现为与南海等深线相一致的海盆模态,风场上主要表现为弱的冬季风或弱的夏季风,各个季节的海-气耦合模态都主要反映了SST-蒸发-风反馈这样1种正反馈的海-气相互作用过程,而且冬季风期间这种相互作用要更强烈些。时间系数均主要表现为一致的上升趋势和1976年前后的年代际突变,以及与ENSO相关的年际变化特征。冬、夏季弱的季风对应暖SST的特征体现了这种耦合模态隔季相关的特征,都对应夏季华南旱(涝)、江南涝(旱),华北、山东半岛旱(涝),东北涝(旱)这样1种波列状的旱涝相间分布。     

赤点石斑鱼人工配合饵料中蛋白质最适含量的研究

本文探讨了不同蛋白质含量的配合饵料对赤点石斑鱼（Epinephelusakaara）生长的影响。通过60d度验得出：在各配合饵料组中，蛋白质含量为49．52％的试验的相对增重率（46．84％）体长相对增长率（15．96％）、蛋白质效率（60．35％）和饵料转化率（29．85％）等均为最佳。配合饵料组鱼体肌肉营养成分（蛋白质、脂肪、氨基酸和鲜味氨基酸）也均优于对照组，而更接近野生鱼。经回归方程分析，赤点石斑鱼人工配合饵料中蛋白质最适含量为48．37％～49．24％。     

Characteristic analysis on oxygen isotopic tracer in the East China Sea and waters to east of the Ryūkyū-guntō

Samples of O isotopic tracer were mlleMed at Sections P₃,P₂₅,P_cM-t/2-E and P_CM-1/2.w in both the Fast China Sea and the area to the east of the Ryūkyū-gunto during October-November,1991.Analytical results of the δ¹⁸O are as follows: (1) In the Kuroshio area,the δ¹⁸O isolines are almost parallel to the 200 m isobath.The value of δ¹⁸O is negative and reaches minimum mt the main axis of the Kuroshio,and increases on both sides.(2) In the Taiwan Warm Current (TWC) area there is a high δ¹⁸O tongue extending to the northeast.(3) In the area near the coast,the distribution of δ¹⁸O isoline shows that the Changjiang River runoff diffuses seaward and the land-ocean isotopic effect from the nearshore to the offshore.(4) The values of δ¹⁸O are from -1.0×10^-3 to -0.5×10^-3 in the shelf.(5) There is a low mre of δ¹⁸O value(<-1.6×10^-3) at the 600 m layer in the Kuroshio area,which is quite in accord with the existence of a low salinity mre (S G 34.30) between the 600 and 800 m layers in the same area.Finally,the mrrelations of the δ¹⁸O with the salinity and temperature,the upwelling and so on are discussed.     

海湾扇贝肝素样多糖分离方法的研究

于1992年1月-1993年2月，对从海湾扇贝中提取获得的糖胺聚糖（GAG）用乙醇和溴化十六烷基三甲铵（CTAB）分级分离，并对所得制品用琼脂糖凝胶电泳和高效液相色谱验证，以研究一种简便、快速的分离提纯方法。结果表明，扇贝GAG水溶液在乙醇量60％时分离获得的级分，其GAG－GTAB给合物再用2.0 mol/LNaCl溶液解离得到的主要级分，琼脂糖凝胶电泳和高效液相色谱均显示出单一区带，红外光谱类似干肝素的。证明这一提纯过程是一简便、快速的分离提纯方法。     

中国沿海星虫动物门名录

取1980～1989年间在我国沿海进行星虫动物区系调查的标本和有关资料做了整理、鉴定,共39种,分隶于2纲,4目,6科,12属。其中1种在我国为首次记录。     

Current status of bacteriological parameters and DOC/POC in Xiamen coastal waters

The surface and bottom waters samples were collected from six locations in Xiamen western sea. The quantified estimation of bacterial production (3H-thymidine method) and observation of bacterial heterotrophic activity (14C-glucose method) have been made in order to have a better understanding of the role of marine bacteria and their activities. The results showed that the mean value of bacterial heterotrophic activity was 9×108 cells/(L.h) in the surface waters and 2.6×108 cells/(L.h) in the bottom waters. The mean value of bacterial production was 38×108 cells/(L.h) in the surface waters and 7.1×108 cells/(L.h) in the bottom waters. The relationship between bacterial production, heterotrophic activity, POC and DOC measured during this survey were discussed. The good understanding of the relationship between bacteria activity and total coliform was addressed.