花尾胡椒鲷室内与室外人工育苗的比较研究

将花尾胡椒鲷(Plectorbinchus cinctus)的受精卵在室内育苗池和室外大池不同环境下进行人工育苗比较试验,在26℃～28．8℃的水温条件下,室内培育盐度保持26左右,室外大池的盐度变动范围为26．2～22．9,经过36d的培育,结果显示：①在室内育苗池培育的鱼苗成活率最高为13．9％,最低为6．4％,平均为11．0％;室外培育的成活率仅为6％,室内培育相对室外培育的成活率增加45．5％。②室内培育的鱼苗平均体长为34．5mm,室外培育为52．1mm,室外培育相对室内培育鱼苗体长增加33．6％。③活力试验。室内培育的鱼苗成活率最高为94．8％,最低82．4％,平均为90．9％,而室外培育的鱼苗成活率则达到99．6％,室外培育相对室内培育鱼苗活力试验的成活率增加8．0％。因此,室内培育鱼苗的成活率相对较高,但生长缓慢,活力较差;室外培育鱼苗成活率相对较低,但生长快,活力强。     

杜氏鰤人工苗养殖生物学特性及养殖技术研究

报道杜氏鰤(Seriola dumerili)人工苗养殖生物学特性及养殖技术研究结果。在海区水温6-30．5℃。海水盐度14．33，溶解氧6．5-7．3mg／L，pH7．5-8．1，水流为15-35cm／s的网箱中，杜氏鰤人工苗叉长40-50mm，体质量1．5-1．7g，经208d养殖，叉长达到330-388mm，体质量达到950-1400g，饲料系数为11，成活率为71．7％；养殖720d，体质量达4．5-6．5k，饲料系数为8；养殖l080d，体质量达7．5-11．5kg，饲料系数为7；养殖l440d，体质量达13．，15．5k异，饲料系数为6；养殖l800d，体质量达15．5-18．5kg，饲料系数为5。第4年性腺发育成熟，4-5月份，海上网箱人工催产，平均每尾雌鱼可产卵1．8kg左右。     

提高日本对虾人工育苗成活率的研究

通过日本对虾Penaeusjaponicus人工育苗中饵料配给、水质处理和控制,以及幼体病害防治的单因子和多因子正交试验及大面积生产验证,对提高日本对虾人工育苗成活率的几项关键措施进行了探讨。结果表明：（1）在Z期,添加螺旋藻Spiralsp.粉10g·（1．0×106尾·d）-1、光合细菌2ml·（m3·d）-1和Z3期添加卤虫Artemia无节幼体1-2个·ml-1,使Z1－M1期幼体的成活率提高10％-15％;（2）用36％甲醛0．065－0．13mmol·dm-3和光合细菌2ml·（m3·d）－1处理并改良育苗水质,以及在N期1次性加水75％,至M3期加满,P1-5期换水6％－10％,P6-10期换水15％－20％,用此方法控制育苗水质,作用显著;（3）用间投联用0．5g·（m3·d）－1抗菌素的方法预防幼体细菌病效果良好;（4）在10个总水体为543m3的育苗池中,共育出P8-10期的虾苗3．026×107尾,单位平均出苗量为5．5×104尾·m－3,N-P8-10期的成活率最高达65％,平均为54．6％。     

温度、盐度和底质对大竹蛏稚贝生长及存活的影响

采用单因子分析方法,在室内模拟设置10个温度梯度(6-36℃)、10个盐度梯度(4‰-40‰)和4种底质(细粉沙、细沙、粗沙、混合沙组)及3个厚度梯度(5、10、30mm),研究温度、盐度和底质对大竹蛏稚贝生长及存活的影响.结果表明:1)在盐度为21.4‰的条件下,大竹蛏稚贝存活及生长的适温范围为6-30℃,最适温度范围为21-30℃;15℃以上随温度升高日生长率逐渐增大,30℃个体日生长率为1.82%,21℃组成活率最高达88%.2)在温度为21.6-28.6℃条件下,大竹蛏稚贝存活及生长的盐度适宜范围为20‰-32‰,最适盐度范围为20‰-28‰;盐度20‰时成活率最大为85%,盐度24‰时个体日生长率最大为1.72%.3)大竹蛏稚贝对底质环境无明显的选择性,沙的粒径大小对稚贝成活率和日生长率均无显著影响(P＞0.05);但稚贝在不同厚度底质中的成活率和日生长率存在显著差异,10和30mm组的成活率和日生长率均显著高于5mm组的成活率和日生长率(P＜0.05).     

斜带髭鲷室外人工生态系育苗试验

本文系斜带髭鲷鱼苗室外水泥池不同生态系的育苗试验．在育苗前的“养水”期 间,1号池接入小球藻、微绿球藻、扁藻、金藻、轮虫、桡足类、枝角类等生物饵料;2号 池仅接入小球藻、轮虫生物饵料．在水温19．1～23℃、比重1．019、pH值8．5的条件 下．2池鱼苗经100d的培育后,平均全长各为31mm和29mm,平均体重各为0．90g 和0．75g,成活率18．5％和10．1％．试验表明:在育苗前期,生物饵料的多样性有利于 开口仔鱼的摄食和营养,也利于鱼苗的生长发育和成活率的提高．     

钝缀锦蛤(Tapes dorsatus)稚贝的温度和盐度耐受性研究

本实验在室内控制条件下,采用实验生态学方法研究了钝缀锦蛤(Tapes dorsatus)稚贝对温度和盐度的耐受性.在温度耐受性方面:(1)稚贝在低温端温度为4℃、6℃、8℃、10℃时保持90％～100％存活的时间分别为0?d、2?d、3?d、7?d;在高温端温度为33℃、34℃、35℃、36℃时保持90％～100％存活...     

黑鲪生态生长效率周年变化的研究

于1983年12月-1984年5月和1990年6月-1991年1月以中国科学院海样研究所生物培育楼养殖黑为材料，进行黑周年的摄食-生长实验，以探讨其生态生长效率变化规律。结果表明，作为冷温性鱼，黑在4．0－27．3℃水温条件下都有摄食；平均日摄含量为2．4－10．0g，相对体重的百分比为1．1%-4.4%．单见，这二者的周年变化趋势基本一致；平均体重日增长量以4，6，7月和10－12月份较高。生态生长效率波动于6．5%-34．7%范围内，年平均为16．7％。     

干露胁迫对青蛤呼吸代谢及抗氧化相关酶活力的影响

研究了不同时间和温度下干露对青蛤(Cyclina sinensis)失水率、存活率、呼吸代谢相关酶及抗氧化相关酶的影响。结果表明,随着干露时间的增加,青蛤的失水率显著增加,且高温状态下青蛤失水加剧;在3℃和10℃条件下干露48 h未出现死亡现象。在20℃条件下,干露时间超过24 h后,青蛤出现死亡现象,死亡率为3.33%,至48 h死亡率增加至5.33%;随着干露时间的增加,青蛤的呼吸代谢相关酶的活性整体呈现显著下降趋势(P<0.05),10℃条件下青蛤的呼吸代谢相关酶的活性整体高于3℃和20℃;随着干露时间的增加,青蛤的抗氧化相关酶的活性呈现与青蛤呼吸代谢相关酶相似的变化趋势,且不同温度条件下,干露时间达到48 h时,青蛤的抗氧化相关酶活性显著低于对照组(P<0.05)。综上表明青蛤受干露胁迫时具有一定的自我调节能力,但干露时间超过其耐受限度时会对青蛤的生理状态造成影响。     

三疣梭子蟹(Portunus trituberculatus)的保活参数优化及其代谢响应

为延长三疣梭子蟹(Portunus trituberculatus)在捕捞后的存活时间,在优化保活温度和充氧量的基础上,再采用基于核磁共振(NMR)的代谢组学技术,比较分析了三疣梭子蟹前鳃代谢谱在充氧和不充氧保活过程中的变化。结果发现, 12 ℃下的三疣梭子蟹存活率最高, 80%的三疣梭子蟹能存活3.5 d。加大充氧量能提高三疣梭子蟹的存活率, 3.6 L氧气可满足一只三疣梭子蟹成蟹存活到3 d以上。因此,保活三疣梭子蟹的适宜温度和充氧量分别是12 ℃和3.6 L。不充氧保活会导致三疣梭子蟹前鳃中乳酸、丙氨酸和葡萄糖等代谢物的快速积累,但充氧保活可抑制这些代谢物的变化,表明氧气通过缓解三疣梭子蟹前鳃的缺氧和渗透压失衡,从而有效延长三疣梭子蟹的存活时间。研究结果为三疣梭子蟹的保活运输提供可借鉴的方法和理论参考。     

三苯基氯化锡对黑褐新糠虾的毒性效应

于 1 992年 7月在青岛胶州湾西岸采集黑褐新糠虾 ,经实验室常年培养驯化后作为实验材料 ,研究了三苯基氯化锡 (TPTC)的急性毒性效应及其对糠虾繁殖、生殖周期和种群的慢性毒性影响。结果表明 ,在急性毒性实验中 ,TPTC对糠虾的半致死浓度为 2 5× 1 0 - 9g/L( 2 4hLC50 )和 1 5× 1 0 - 9g/L( 4 8hLC50 ) ;慢性毒性实验结果表明 ,TPTC能影响糠虾种群的世代繁殖 ,2× 1 0 - 9g/L的TPTC能使糠虾首次生育的年龄延迟 3d ,产幼总数比对照组减少80 %以上 ,1× 1 0 - 9— 2× 1 0 - 9g/L的TPTC能导致糠虾生殖周期延长 3— 4d ,在生殖期内的死亡率上升 30 %— 55% ,暴露于 0 2 5× 1 0 - 9— 2 0 0× 1 0 - 9g/LTPTC中的糠虾其子代的在 6× 1 0 - 9g/LTPTC中存活能力下降。可以认为 ,1× 1 0 - 9g/L的TPTC可导致糠虾种群的衰亡。     

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.