有机锡对海洋微藻的生理效应 Ⅰ.三苯基锡和三丁基锡对光合色素含量的影响

于1991年4月－1992年五月，以金藻和扁藻为材料，用室内一次培养法研究三苯基锡（TPTC）和三丁基锡（TBTC）化合物对光合色素含量的影响。结果表明，两种有机锡对两种藻均有影响，在0．2—0．4μg／L的浓度时有轻微毒性；浓度大于0．5μg／L时，能使光合色素明显减少。对于两种藻叶绿素a72hEC50影响结果：TBTC和TPTC对金藻的均为0．59μg／L；对扁藻的，TBTC是0．87μg／L，而TPTC本出现半效应浓度。对于两种藻的类胡萝卜素72hEC50影响结果：金藻，TPTC是0．57μg／L，TBTC是0．49μg／L；扁藻，TBTC是0．89μg／L，TPTC也未出现半效应浓度。认为，两种有机锡对光合色素有明显的破坏作用。     

热致死小球藻生物富集Cr3+的研究

研究了热致死小球藻对微量Cr^3 的生物吸附富集和机理。结果表明，培养72h左右的热致死小球藻吸附富集Cr^3 的能力最强；当pH为4．5—5．0，藻浓度为1—2g／L时，死体藻对Cr^3 有较好的生物吸附作用；随着Cr^3 浓度增加，单位质量藻的Cr^3 吸附量呈上升趋势，但其Cr^3 吸附率却急剧下降。热致死小球藻对Cr^3 的吸附可以用Freundlich模型描述，拟合方程为：q＝5．3369C11/2.6295，R^2＝0．9974；在生物吸附的起始阶段，藻体对Cr^3 的吸附较快，40min左右时藻体达到最大吸附量。     

NaHCO3浓度对塔胞藻、小球藻和新月菱形藻生长的影响

在温度为 ( 2 2± 1 )℃ ,盐度为 2 8的条件下 ,用不同浓度的NaHCO3( 0 ,1 0 0 ,2 0 0 ,40 0 ,80 0 ,1 2 0 0和 1 60 0mg/L)对青岛海洋大学微藻种质库保存的塔胞藻 (Pyramidomonassp.)、小球藻 (Chlorellaspp .)和新月菱形藻 (Nitzschiaclosterium )进行培养。实验结果表明 ,NaHCO3浓度对 3种海洋微藻生长的影响差异显著 ,经过 6d的培养 ,塔胞藻和小球藻的细胞浓度都在NaHCO3浓度为 1 2 0 0mg/L时达到最大值 ;新月菱形藻的细胞浓度在NaHCO3浓度为 40 0mg/L时达到最大值。     

锶诱导的氧化胁迫对叉鞭金藻(Dicrateria inornata)的影响

采用不同浓度的锶胁迫方法研究了叉鞭金藻生长、叶绿素、MDA含量及三种抗氧化酶SOD、CAT、GPX活性的变化。结果表明，在实验设计的各种Sr^2 浓度内叉鞭金藻均能生长，但Sr^2 浓度较高时生长受到不同程度的抑制，细胞数量比对照组分别减少15．9％和51．0％；叉鞭金藻中叶绿素含量随着Sr^2 浓度的升高而降低，呈负相关关系；叉鞭金藻中MDA含量在较低Sr^2 浓度下稍呈下降趋势，但与对照组相比并无显著差异，而在23．04mmol／L Sr^2 浓度时是对照的1．25倍；低Sr^2 浓度时，叉鞭金藻中蛋白质含量没有大的变化，当浓度超过5．76mmol／L时则引起蛋白质含量下降；叉鞭金藻中抗氧化酶SOD在低Sr^2 时分别降低12．5％、7．5％和9．5％，高Sr^2 时显著升高，为对照组的85．7％；CAT、GPX活性在低Sr^2 浓度时差别不大，但当浓度为23．04mmol／L时升高显著，比对照组分别增加了19．8％和74．4％。     

均匀设计在后棘藻培养基中的应用

将均匀设计的方法应用于一种海洋微藻：后棘藻（Ellipsoidion)培养基的优化。设计了硝氮、氨氮、磷酸盐三因素各五个浓度水平的试验，根据均匀设计表设计了10种培养基，检测细胞浓度、脂肪酸含量和产量。结果表明：在硝氮、氨氮浓度均为1．92mmol/L，磷酸盐浓度为0．082mmol/L，细胞浓度达到最大值167．23mg/L。在硝氮浓度为0．84mmol/L，氨氮浓度为3．38mmol/L，磷酸盐浓度为0．07mmol/L时，EPA含量达到最大值7．748％。在硝氮浓度为0．915mmol/L，氨氮浓度为1．92mmol/L，磷酸盐浓度为0．072mmol/L时，EPA产量达到最大值9．999mg/L。     

硅浓度对筒柱藻B169生长、叶绿素荧光参数、总脂含量及脂肪酸组成的影响

本文以底栖硅藻筒柱藻(Cylindrotheca sp.)为实验材料,研究了一次性培养过程中,不同硅浓度即:0mg/L(Si0)、8.35mg/L(Si1)、33.4mg/L(Si2)、133.6mg/L(Si3)、534.4mg/L(Si4)和1068.8mg/L(Si5)对藻细胞密度、叶绿素荧光参数、叶绿素含量、总脂含量及脂肪酸组成的影响。结果表明:第5~9d,筒柱藻的细胞密度随硅浓度的增加而增加,硅浓度较高的Si3、Si4和Si5处理组的细胞密度显著高于硅浓度较低的Si0、Si1和Si2处理组的细胞密度。第1~9d,Si5处理组的荧光参数F_v/F_m(PSII的最大光能转换效率)和F_v/F_o(PSII的潜在活性)均显著低于其它处理组。第3~6d,Si3处理组的上述荧光参数均显著高于其它处理组。第1~7d,Si4和Si5处理组的荧光参数φPSII(PSII的实际光能转化效率)和rETR(相对电子传递效率)均显著低于其它处理组,其中Si5处理组的上述荧光参数最低,其次是Si4处理组。筒柱藻的叶绿素含量随着硅浓度的增加而增加,到Si3处理组叶绿素含量达最高值,之后叶绿素含量下降,Si3处理组的叶绿素含量最高,Si0处理组的叶绿素含量最低。筒柱藻的总脂含量随硅浓度的增加而降低,Si0处理组的总脂含量最高,Si5处理组的总脂含量最低。筒柱藻的主要脂肪酸是1 4:0(5.1 5~8.7l%)、16:0(22.40~42.27%)、1 6:1n-7(3l.40~33.12%)、16:3n-4(1.89~8.45%)、20:4n-6(5.95~11.39%)和20:5n-3(EPA)(3.47~8.07%)。饱和脂肪酸含量随着硅浓度的增加而降低,多不饱和脂肪酸含量随着硅浓度的增加而增加,硅浓度对单不饱和脂肪酸的影响差异不显著。经济价值较大的20:4n-6和20:5n-3含量均在Si3和Si4处理组达到最高值。     

盐田藻垫生长与环境因子关系的研究

本文研究测定了卤水浓度、营养盐、温度、光照强度、pH等环境因子对盐田藻垫生长的影响。提出了利于藻垫生长的上述环境因子的最适范围及最适点：1．卤水浓度为6—12°Be。2．在无机氮0～8mg／L，无机磷0～0．8mg／L的范围内，藻垫生长随营养盐浓度的增加而增加。3．温度为30℃。4．在自然条件下，光照越强越有利于藻垫生长。5．pH为8．5。     

有机锡对海洋微藻的生理效应──Ⅱ.三苯基锡和三丁基锡对扁藻和金藻光合作用的影响

于1991年4月-1992年1月，分别用不同浓度的三苯基氯化锡（TPTC）和三丁基氯化锡（TBTC）培养扁藻和金藻，测定24，48和72h两种藻的净光合速率和生长速率。结果表明，TBTC对两种藻的毒性大于TPTC；TPTC和TBTC在浓度为0．2μg／L时，对两种蕉的光合作用有轻微影响；浓度大干0．4μ/L，两种藻的光合作用不同程度地受到抑制。扁藻对有机锡的耐受力大于金藻：扁藻用两种锡处理后，第一天受害最严重，第二天和第三天光合速率开始恢复；金藻经TPTC处理后随时间加长光合速率稍有恢复，而经TBTC处理后则未出现恢复现象。     

IAA对球等鞭金藻和棕鞭藻生长及总脂含量的影响

本文研究了0.1~5mg/L的3-吲哚乙酸(IAA)对球等鞭金藻(Isochrysis galbana)和0.1~3mg/L的IAA对棕鞭藻(Ochromonas neopolitana)的叶绿素荧光参数(PSII最大光能转化效率Fv/Fm、相对电子传递速率rETR、光化学淬灭qP)、细胞密度、叶绿素含量、总脂含量及脂肪酸组成的影响。研究表明,球等鞭金藻和棕鞭藻进行光合作用和生长的最适IAA浓度分别为0.1和0.25mg/L。此条件下,2株藻的Fv/Fm、rETR、qP、细胞密度和叶绿素含量均显著高于对照组和其它处理组。其中,球等鞭金藻的细胞密度和叶绿素含量分别比对照组增加了32.6%和37.1%,总脂含量显著高于其它处理组,但与对照组差异不显著(P0.05);棕鞭藻的细胞密度和叶绿素含量在IAA浓度为0.25mg/L时分别比对照组增加了48.7%和34.4%,总脂含量在IAA浓度为0.5mg/L时显著高于对照组和其它处理组,但与0.25mg/L处理组差异不显著(P0.05)。0.1mg/L的IAA浓度对球等鞭金藻DHA(二十二碳六烯酸)的合成有促进作用,但对其它各脂肪酸(14:0、16:0、16:1n-7和18:1n-9)含量均无显著影响;0.25mg/L的IAA浓度促进了棕鞭藻DHA和多不饱和脂肪酸的合成。研究结果表明,球等鞭金藻和棕鞭藻进行生长和油脂积累的最适IAA浓度分别为0.1和0.25mg/L,此结果为2株藻的大规模培养提供了理论依据。     

利用啤酒废水养殖螺旋藻研究

利用啤酒废水养殖极大螺旋藻(Spirulina marima),研究了废水成分、氮源、藻密度和光照等培养条件对藻生长和蛋白质含量的影响。结果表明,曝气处理的啤酒废水养殖的螺旋藻,相对生长率与CFFRI培养基的几乎一致．蛋白质含量第6天最高,为0．2886g／g干质量,小于CFFRI培养基养殖的。实验确定曝气处理废水养藻的最佳条件是用NaOH调废水pH、藻初始密度取53．8mg／L、光照在1000～10000 1x范围,添加尿素或碳酸氢钠或曝气8h／d。经PSB处理的啤酒废水养殖的螺旋藻,蛋白质为0．4825g／g干质量,与CFFRI培养基养殖的相近。用光合细菌(PSB)处理的废水养藻应控制废水pH为7．0且废水与PSB的体积比为3：1。     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification

An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm.     

A Review of Some Environmental Issues Affecting Marine Mining

This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested.     

Increased Particle Fluxes at the INDEX Site Attributable to Simulated Benthic Disturbance

Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement.     

Determination of In Situ Sediment Shear Strength from Advanced Piston Corer Pullout Forces

The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments.     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations.