An electrochemical study on the effects of marine fouling organisms on steel used in the sea

-Study on the effects of microorganism secretive membrane and covering layer of macrofouling organisms-Balanus reticulatus, Ostrea plicatula, Membranipora, Corophium and Algae on the corrosion of carbon steel and low-alloy steel by the determination of natural corrosive potentials, linear polarization and the polarization curver of dynamic potential scanning through an electrochemical equipment.The results show that the microorganism secretion membrane formed on sample surface has some protective role, during the initial period of exposure (about ten days). Then protective role decreases and corrosive rate increases with the lapse of immersion time. The protective role of some macrofouling organisms is shown in order as follows: Corophium> Balanus reticulatus>Algae>Membranipora>Ostrea plicatula.     

An improved gas chromatographic method for the measurement of hydroxylamine in marine and fresh waters

We present here an improved method for the analysis of hydroxylamine at nanomolar levels, which involves oxidation by Fe(III) and the subsequent measurement of nitrous oxide by electron-capture gas chromatography. The relationship between the pH and salinity of natural waters and the conversion of hydroxylamine to nitrous oxide by Fe(III) is defined, the rates of the reaction are evaluated, and the effects of dissolved O₂, Cu(II), and Hg(II) on the reaction are investigated. The method is linear to more than 300 nM and the standard deviation for a single measurement is 1 nM in the 0–40 nM range, thus exceeding the sensitivity of the spectrophotometric methods by almost an order of magnitude. This method eliminates the effects of pH and salinity that have burdened an earlier gas chromatographic approach, making possible the investigation of this labile substance not only in seawater, but in fresh and brackish waters as well.     

An improved method for the determination of ammonia in seawater

The Liddicoat, Tibbitts and Butler method for the determination of ammonia in seawater has been noticeably improved by replacing the UV lamp with a 300 VA tungsten lamp. The characteristics so achieved, a low blank value (0.012 ± 0.002a.u.), a good molar absorptivity (23.90 × 10⁻³) and a reasonably short reaction time (1 h), are such that this modified procedure is more convenient for routine work in chemical oceanography.     

海洋生物的有机锡化合物污染

由于在工农业上,特别是在海洋防污涂料方面的广泛应用,有机锡化合物已通过各种途径进入海洋环境,使海洋生物普遍受到污染。有机锡化合物是迄今为止由人为活动引入海洋环境最毒的化学物质之一,也是目前已知内分泌干扰物质中惟一的金属化合物,它对多种海洋污损生物具有长期有效的     

指示生物在海洋污染监测中的应用

伴随着社会经济和工业的快速发展,人口的不断增长,在生产和生活过程中产生的废弃物也越来越多,这些废弃物的绝大部分最终直接或间接地进入海洋.当这些废物和污水的排放量达到一定的限度,海洋便受到了污染.污染海洋的物质众多,按污染物的性质和毒性,以及对海洋环境危害方式,大体可以把污染物分成以下几类:一是营养盐类和有机物质,如工业排出的无机氮、磷酸盐等,生活污水中的粪便、洗涤剂等;二是重金属和酸碱类物质如汞、铜、锌、镉等重金属,以及砷、硫、磷等非金属和各种酸碱;三是有毒化学制品,主要是化肥和农药的残留物[1,2].     

防腐高效溶样罐-ICP-MS测定海洋生物体中微量元素

为明确海洋生物体中微量元素的含量状况,开发了一种适合海洋生物体中微量元素准确测定的分析方法。研究采用防腐高效溶样罐对GBW08517（海带Saccharina japonica）与GBW08571（贻贝Mytilus coruscus Goyld）2种国内海洋生物标准物质进行2种不同前处理方法的消解实验,然后应用电感耦合等离子质谱仪（ICP-MS）测试了包括稀土元素在内的33个微量元素。实验结果表明,除个别元素外,测试结果均与标准值相符合,且前处理方法1消解的生物样品测试结果更加准确和稳定。使用防腐高效溶样罐优化了生物样品处理的消解方法,能有效去除生物样品中的有机基体,使ICP-MS充分发挥优势。与以往的消解方法相比,在生物消解中效果优于微波消解,前处理方法1还具有易操作、处理效率高、低试剂消耗、安全性强、避免样品污染等优点。     

Application of a probabilistic method to the analysis of accumulation of toxic substances by marine organisms

The process of accumulation of toxic substances by marine organisms is studied on the basis of the kinetic theory of systems of macroscopic particles (V. I. Belyaev, 1987). The use of stochastic equations makes it possible to evaluate the degree of accumulation of toxic substances in marine organisms and take into account random variations of their concentrations in marine environments. Translated by Peter V. Malyshev and Dmitry V. Malyshev.     

一种改进的随机起伏海面的仿真方法

根据线性滤波器模型的基本原理,提出了一种改进的基于高阶滤波器的随机起伏海面仿真方法.利用Pierson的半经验海浪谱模型,得到了各种不同风速条件下海面随机起伏的仿真结果,并且对仿真结果进行了比较和讨论,结果表明,利用高阶滤波器方法能更加准确地仿真不同风速下的实际海面、更好地再现随机起伏海面的海浪谱特征.这一方法的提出为海浪的物理模拟实验提供了更为准确的数值计算方法,也为研究目标与海面共存条件下高频地波雷达信号的回波特性提供了更好的数值仿真平台.     

Factors responsible for catastrophic extinction of marine organisms at the Mesozoic-Cenozoic boundary

The mass death of organisms at the Cretaceous-Tertiary boundary (KT boundary) resulted in the extinction of approximately half of marine genera. Some taxa had degraded by the end of the Cretaceous to become eventually extinct either before or precisely at the KT boundary. Most of them became extinct immediately at this boundary. The terminal Cretaceous was marked by changes in many environmental processes, which influenced the biota. These included tectonic events, powerful basalt eruptions, falls of large asteroids (impact events), anoxia, transgressions and regressions, cooling and warming episodes, and the chemistry of the atmosphere and seawater. All these factors, except for impact events, could stimulate degradation of some groups of organisms, not their extinction. The Cretaceous-Tertiary boundary was marked by major impact events, which are reflected in the occurrence of the Chicxulub, Shiva, Boltysh, Silverpit, and, probably some other impact craters. Some known craters were left by asteroids at that time or slightly earlier. At least as many asteroids undoubtedly fell into the ocean. The combination of many factors in the terminal Cretaceous harmful for organisms and seemingly unrelated to each other may be likely explained only by a single supreme cause beyond the Solar System.     

Introduction of accumulation-dispersal coefficient of marine organisms

Avoiding the subject for fish accumulation, the traditional view in fish population dynamics has ascribed immigration and emigration of fish to dispersal of fish. The main purpose of this paper is to find a quantity that represents the time rate of accumulation-dispersal of marine organisms, and also has some relation to the horizontal convergence of current velocity of the surrounding water. For this, the accumulation-dispersal coefficient is introduced not in the form of diffusion, but in the same form as the convergence. Since the accumulation-dispersal of organisms is a factor that changes its distribution density, all factors causing the change are first classified to locate the position occupied by the accumulation dispersal. Each factor corresponds to each coefficient appearing in a linearized equation describing the rate of change in the density, averaged over a region or a group. The immigration-emigration coefficient is divided into three coefficients of passage, accumulation dispersal and diffusion velocity. For the organisms ranging in a nearly horizontal layer, the accumulation-dispersal coefficient is shown to equal the area-averaged horizontal convergence of organismal velocity relative to land, which is the sum of the area-averaged horizontal convergences of swimming velocity relative to water and of current velocity. However, the area-averaged convergence of current velocity associated with the accumulation-dispersal coefficient for a region is shown to be somewhat different from the usual one.     

Formation and identification of PAHs metabolites in marine organisms

In this study, the development of the technique APCI⁺ LC/MS/MS allowed the detection of phenanthrene, pyrene and metabolites of alkyl homologs in fish bile (in situ) and in urine of crabs. Laboratory experiments were carried out exposing crabs from an unpolluted mangrove (Barra de Guaratiba) to phenanthrene, and to the alkylated homologs 1-methyl phenanthrene and 2,6,9-trimethyl phenanthrene. Urine samples were collected at 0, 24, 48, 72, and 96 h. Fishes were captured from strategic sites from Guanabara Bay. Hydroxylated metabolites of phenanthrene, epoxides, orthoquinone and glucoside conjugates were identified in both samples. The method APCI⁺ LC/MS/MS showed to be effective in a preliminary assessment of phenanthrene metabolite formation, although the low concentrations of 1-methyl phenanthene and 2,6,9-trimethyl phenanthrene did not allow a systematic evaluation of data. The method, however, proved to be excellent tool for studies of PAHs metabolites due to the high selectivity, sensitivity and separation attained.     

An improved method for the determination of phytoplankton chlorophyll using N,N-dimethylformamide

Non volatile N, N-dimethylformamide (DMF) at room temperature is proposed as a new solvent for determining the chlorophylla in cultured and natural phytoplankton samples. Advantages of DMF compared to the solvents ordinarily used are (1) higher extraction efficiency, (2) rapid extraction time of 30 min, (3) simple extraction procedure requiring neither extra heating nor grinding, but soaking, and (4) a long stable life of chlorophylla (at least one month at 5°C in the dark).     

Scale dependence of accumulation-dispersal coefficient of marine organisms

An attempt is made to find a relation betweenK, the absolute value of accumulation-dispersal coefficient of marine organisms referred to a region or a group (Kawai, 1986a), andL, the square root of the area of the region or the group over which the distribution density of organisms is averaged.K is estimated as shown below. For appropriate sampling time-intervals,K becomes greater than other coefficients such as population growth coefficient. Using this result, an order of magnitude ofK dependent onL is estimated from various data of temporal change in density. With the aid of a dependenceQL ^–2/3 (Kawai, 1985b), a relationKL ^–2/3 is predicted for 30 cmL 30 km, whereQ andK are the root-mean-square values of area-averaged horizontal divergence of near-surface flows and of the accumulation-dispersal coefficient, respectively. The reason whyK tends to have the order of magnitude of weak or mediumQ is discussed. The doubling-halving time of the distribution density due to accumulation-dispersal,T, is related toK byT=(log_e2)/¦K¦L ^2/3. Finally, sampling time-intervals to estimate accumulation-dispersal coefficients are referred to.     

Causes of the great mass extinction of marine organisms in the Late Devonian

The second of the five great mass extinctions of the Phanerozoic occurred in the Late Devonian. The number of species decreased by 70–82%. Major crises occurred at the Frasnian–Famennian and Devonian–Carboniferous boundary. The lithological and geochemical compositions of sediments, volcanic deposits, impactites, carbon and oxygen isotope ratios, evidence of climate variability, and sea level changes reflect the processes that led the critical conditions. Critical intervals are marked by layers of black shales, which were deposited in euxinic or anoxic environments. These conditions were the main direct causes of the extinctions. The Late Devonian mass extinction was determined by a combination of impact events and extensive volcanism. They produced similar effects: emissions of harmful chemical compounds and aerosols to cause greenhouse warming; darkening of the atmosphere, which prevented photosynthesis; and stagnation of oceans and development of anoxia. Food chains collapsed and biological productivity decreased. As a result, all vital processes were disturbed and a large portion of the biota became extinct.     

ICP-AES测定海洋生物体中13种元素的微波消解条件优化

报道了微波密闭消解正交试验条件优化电感耦合等离子体发射光谱法(ICP-AES),同时测定8种海洋生物体中硒、铁、锰、锌、钙、镁、锶、砷、镉、铬、铜、铅和镍等13种元素含量的实验结果。优化后的样品消解条件为加入的HNO3V:H O2 2V=6.0 mL:1.0 mL,第二步程序升温温度为170℃,消解时间20 min;测定标准曲线相关系数大于0.999,相对标准偏差为0.30%~2.55%,加标回收率为92.0%~104.8%,方法检出限为0.0010~0.0468μg/g。结果表明,优化后方法测定操作简便、具有高的灵敏度、准确度和精密度,且能多元素同时测定,适合于海洋生物样品中这些元素含量的准确测定,并可为评估海产品食用安全提供科学依据。     

海洋生物抗炎活性物质研究进展

炎症是一种常见生理反应,在疾病的发生发展过程中具有非常重要的作用。炎症反应既具有阻止致炎因子蔓延全身和清除致炎因子、修复损伤组织和器官等积极作用,也有引发细胞和组织变性和坏死,甚至诱发某些肿瘤的潜在危害。目前临床常用的抗炎药分为甾体类和非甾体类抗炎药,它们常伴有胃肠损伤等各种副作用。海洋独特的自然环境孕育了独特而多样的抗炎活性物质,如萜类、生物碱、多糖类、多肽类、脂肪酸类和聚酮类化合物等。这些独特的抗炎活性物质因具有较好的抗炎效果和较少的副作用,从而备受关注。本文综述了近年来具有抗炎活性的海洋生物活性物质及其衍生物的研究进展。     

海水双壳类减数分裂器的一种免疫荧光显微观察方法

为定性并定量研究海水双壳类受精过程中纺锤体和染色体的动态,改进了一种免疫荧光显微观察方法,包括样品的预处理、荧光染色和荧光显微观察.本方法适用于同步观测海水双壳类的纺锤体和染色体,具有操作简捷、清晰度高的优点.     

海洋自然资本评估中生物能值转换率的研究

自然资本评估是研究生态系统服务与社会经济发展的重要方式。由于海洋具有特殊性和复杂性、开放性、流动性和多层次耦合性等特点,海洋自然资本评估方法的研究进展缓慢。能值分析理论通过能值转换率将生态系统内流动和储存的各种不同类别的能量和物质转换为同一标准的能值,可衡量和比较不同等级的能量价值,系统完整地反映自然资本价值,这一特点是其他评估方法所缺乏的。为精确量化海洋生物资本价值,本研究引入海洋食物网信息能流图和生态系统能量传递规律,提出了生物能值转换率的经验公式,即Tn=T1·E^1-nL(T1为初级生产者的太阳能值转换率,n为营养级,EL为林德曼效率)。为验证经验公式的可行性,选用相关案例进行了研究,得到海洋食物网中不同食性生物所处营养级及其相应的能值转换率。经验公式有一定误差,具体应用时应通过调研文献和相关数据,确定关键参数的取值范围以提高准确性。本研究得出的经验公式简化了海洋生物能值转换率的计算方法,促进了能值分析理论在海洋自然资本评估中的进一步应用。     

微塑料对海洋生物生态毒理学效应研究进展

海洋环境中的微塑料主要来源于陆源塑料垃圾输入、海上船只塑料垃圾的丢弃和水产养殖业漂浮装置的废弃等.微塑料的大小、形状和颜色与海洋生物的食物相似,容易被海洋生物误食,由于微塑料自身的毒性及其表面吸附的有毒化学物,对海洋生物及其生态系统具有直接和潜在的危害.本研究主要综述了微塑料对海洋生物产生影响的途径、毒性效应及其效应机制的研究进展状况;提出未来应重点加强微塑料环境浓度的长期效应、微塑料与其他污染物的联合效应及其机制、微塑料效应的生物标志物筛选以及生态风险评估技术的研究等.