海上净化实验舱

已报道的关于大洋水中某些痕量金属的基线浓度,总的说来是随着经历的年代而一直在减少的。这样,在文献中看到的大部分有关痕量金属浓度的数据就似乎没有什么价值,而只不过是污染水平的指标罢了,因为,实验室之间精心的相互校正实践已证明,只有严格净化的采样、操作和分析技术才会产生准确的数据。     

与辐射对流过程有关的热带环流:用全球谱模式所作的数值试验

一、引 言 在热带地区,太阳辐射和云辐射的互相作用过程对于数值天气预报来说是头等重要的。1983年 6月 WCRP的报告指出,目前的数值试验确认:时间平均热带环流的模拟(热带环流的时间平稳模拟)对对流和对流与辐射的相互作用是十分敏感的。这些物理过程的主要作用是通过加强的水分循环使对流加热加强,而水分循环的加强是由热带地区的水汽供应的增加和降水率的增加所造成的。 这篇文章描述了欧洲中期天气预报中心全球谱模式两个旬积分的结果。其目的是为了确定在热带地区的对流加热和降水率对辐射的作用。每一个模式的积分是从1979年 6月 11日格林威治时间12点的初始状态开始的,并且适用于若干天以后发生的印度夏季风迅速加强的时期。     

Biochemical and histological responses in mussel (Mytilus edulis) exposed to North Sea oil and to a mixture of North Sea oil and alkylphenols

Several environmental chemicals are suspected to be responsible for adverse health effects on the reproductive system in various organisms. During this work, environmentally relevant concentrations of North Sea oil were used alone or in combination with alkylphenols and additional PAH to study the effect on vitellogenin-like protein expression and gonadal development in mussels. North Sea oil (0.5 ppm) induced the expression of phospho-proteins in both sexes indicating that some compounds are oestrogen-mimics. This induction was not seen in samples dosed with the mixture but signs of toxic effects were observed in the gonads. Indeed, numerous degenerating ovarian follicles in females and foci, similar to vertebrate melanomacrophage centres, were observed in testes.     

PRELIMINARY REPORT ON SUSPENSION CULTURE OF CLON OF PORPHYRA YEZOENSIS CONCHOSPORANGIAL FILAMENTS IN THE PRODUCTION OF CONCHOSPORES FOR PURPLE LAVER AQUACULTURE

InSpringof1990,carposporesofboyeamsiswerecollected,gendnatedandgrewuptothefree-livingConchocelis,whichproducedconchosporangialfilaments.Allexperimentswereconductedincultureboxeswithlightandtemperaturecontrol.Theresultsofanumberofexperimentsareasfollows:1.Afterthedevelopmentofconcho-sporangialfilamellts,theycanbecultivatedalone,andnormallydevelopanddischargealargenumberofconchospores.2.Thesuspensionconchosporangialfilamentusedinpresentworkhavebeenvegetativelypropapatedmanytimesinseveralyears.…     

美国长岛湾缺氧现象及其治理对策综述

近年来,缺氧(hypoxia)现象成为世界范围大洋沿岸水域的一个主要环境问题.本文介绍了由美国环境保护署协调进行的“长岛湾研究”项目对缺氧现象的成因、影响及其与海洋富营养化的关系所做的研究,同时介绍了治理缺氧所采取的对策.     

对地球大气和表面研究的卫星数据处理和分析软件系统

一、引 言 在地球科学发展中现在正出现两个重要的趋势。一个是传统的研究地球部分的定向学科的方法。它正慢慢地让位於更全面的多学科的方法,该方法把地球和大气看成是一个动态的综合系统。另一个是空间观测方法,或更确切地说是卫星遥感,它正成为地球科学各学科如:海洋学、气象学、生物学、地质学和地球物理学的标准研究工具。 鉴于这种趋势,加州空间研究所一直都在开发卫星数据处理和分析软件系统,来支持多学科的及综合研究计划。该系统叫做OASIS(海洋大气卫星图象系统),它有助於处理地球的大气和表面(陆地和海洋)的科研及教学活动的开展。     

长江口及冲淡水区叶绿素a、细菌、ATP、POC及微生物呼吸作用速率之间的关系

1986年7月作者在长江口及其冲淡水区对水体细菌丰度、叶绿素a、ATP、POC的浓度和微生物呼吸作用耗氧速率进行了测定和研究。结果表明,高细菌丰度值出现在口门附近,与悬浮物浓度有关,在该区域,细菌是ATP的主要贡献者和溶解氧的主要消耗者,ATP与POC之间存在着相关性。在稀释区(盐度25—30),由于硅藻的旺发使浮游植物取代了细菌而成为ATP的主要贡献者,同时浮游植物的呼吸作用成为溶解氧消耗的主要因素。叶绿素a和ATP之间以及ATP和POC之间均存在着明显的相关性。文章还估测了微生物碳对POC的贡献。     

中型海洋围隔生态系中汞通量、形态和收支的研究

在海洋围隔生态系实验中加入迄今最低浓度的无机汞,以研究汞的迁移通量、形态分布和收支。加汞后,汞从水柱中被排除的行为可用一级反应动力学描述。在该生态系内汞被排除的半寿期,与初级生产力和浮游植物特性如个体大小、浮游能力等有关。对照围隔生态系内,0.01μg Hg/cm~2·a的汞垂直通量与海湾现场测量值一致。在自然条件下,溶解汞是水中的主要形态,占73％。加汞后,颗粒汞迅速上升,可达70％以上。浮游植物对汞的富集因子为10~5级。汞在沉积物、器壁和水体中的回收只占52.3％。     

Implications of seasonal priming and reproductive activity on the interpretation of Comet assay data derived from the clam, Tapes semidecussatus Reeves 1864, exposed to contaminated sediments

We explore the use of the clam Tapes semidecussatus Reeves 1864 as an indicator for the presence of potentially genotoxic substances in estuarine sediments. The limitations associated with the interpretation of Comet assay data (expressed as % DNA in tail) in terms of clam reproductive state, size (age) and thermal exposure history following laboratory acclimation are discussed. Hatchery-reared clams, subjected to ambient temperature fluctuations during growth, were exposed in vivo under laboratory conditions for three weeks to sediment samples collected from a polluted site and a "clean" reference site. The DNA damage observed in haemocytes, gill and digestive gland cells was significantly higher in animals exposed to contaminated sediment compared to those exposed to sediment from the reference site. The extent of DNA damage recorded was not correlated with size (age). Spawning was not observed during the experiment. Nevertheless, clams with well-developed gonads showed a statistically higher degree of DNA damage in gill and digestive gland cells- but not haemocytes, demonstrating an increased sensitivity to potential genotoxic compounds, possibly caused by impaired DNA repair capacity due to reproductive activity. Furthermore, the degree of DNA damage in clams exposed to contaminated sediments was higher in autumn and winter compared to spring and summer, suggesting an effect of seasonal priming.     

Esterification of vertebrate-like steroids in the eastern oyster (Crassostrea virginica)

The esterification of two model vertebrate steroid hormones - estradiol (E2) and dehidroepiandrosterone (DHEA) - was studied in the oyster Crassostrea virginica. The activity of acyl-CoA:steroid acyltransferase was characterized in microsomal fractions isolated from oyster digestive glands. The apparent Km and Vmax values changed with the fatty acid acyl-CoA used (C20:4, C18:2, C18:1, C16:1, C18:0 or C16:0), and were in the range of 9-17 microM, and 35-74 pmol/min/mg protein for E2, and in the range of 45-120 microM, and 30-182 pmol/min/mg protein for DHEA. Kinetic parameters were also assessed in gonadal tissue. The enzyme saturated at similar concentrations, although conjugation rates were lower than in digestive gland. Preliminary data shows that tributyltin (TBT) in the low microM range (1-50) strongly inhibits E2 and DHEA esterification, the esterification of E2 being more sensitive to inhibition than that of DHEA. Overall, results indicate that apolar conjugation occurs in oysters, in both digestive gland and gonads, at a very similar rate to mammals, suggesting that this is a well conserved conjugation pathway during evolution. Esterification, together with other mechanisms, can modulate endogenous steroid levels in C. virginica, and might be a target for endocrine disrupters, such as TBT.