鬼You人工繁殖和早期发育的研究

采用激素诱导鬼Ｙｏｕ在水池中自然卵受精获得成功。在海水密度１．０２２５ｇ．ｍｌ＾－１，水温２０℃的条件下，受精卵经４８－５５ｈ孵化。在１８－２４℃的温度波动下，于孵后第５－６天卵黄被完全吸收并开始主动摄食，第１５天进入稚鱼期。     

不同孵化方式、培育密度和附着基对瘤背石磺人工繁育的影响

为提高瘤背石磺(Onchidium struma)在胚胎发育和幼虫发育过程中受精卵的孵化速率和幼虫的存活率, 本试验模拟滩涂生态环境对瘤背石磺亲贝进行人工养殖, 并促使其交配产卵。将采集的瘤背石磺新鲜卵块置于盐度18, 水温25～26 ℃的水体中进行孵化。比较3 种不同孵化方式对孵化速率的影响, 并研究不同孔径(1.0～1.5 mm)海绵附着基和不同培育密度对幼虫存活率的影响, 同时结合幼虫在各水层中分布的变化规律, 探索瘤背石磺胚胎发育和幼虫发育过程的关键技术。结果显示, 采用3 种方式(“喷淋”、“露空”和“梯笼”)孵化, 受精卵至出膜面盘幼虫期所需时间分别为8、6 和9 d; 大孔径(1.2～1.5 mm)海绵组对幼虫的附着效果较好, 存活率显著高于小孔径(1.0～1.2 mm)海绵组(P<0.05),且两者均显著高于未添加附着基组(P<0.05); 存活率与不同培育密度的二次多项式回归分析显示, 瘤背石磺幼虫培育密度为55～61 个/mL 时存活率较高。上述结果表明, “露空”孵化方式能显著缩短瘤背石磺孵化所需时间; 在生产过程中, 幼虫培育密度以55～61 个/mL 为宜, 面盘幼虫期投放大孔径海绵作为幼虫附着基能显著提高幼虫存活率且能明显缩短胚胎发育和幼虫发育所需时间。     

温度对墨西哥湾扇贝胚胎和幼虫发育的影响

于１９９４－１９９５年,在中国科学院海洋研究所贝类生态实验室,利用引自美国佛罗里达州并在我国培育繁衍的第二,三代墨西哥湾扇贝作为亲贝,采集精卵,在盐度为３１－３２的条件下,采用控温仪对各个设计实验温度严格控温,进行胚胎和幼虫发育的耐温实验。结果表明,墨西哥湾扇贝受精久的有效孵化温度范围为２３－３０℃,其中２７－２８℃为最适孵化温度;Ｄ形幼虫的生存温度范围是２０－３２℃。当温度升至３４℃时,其存活率     

鲍鱼采苗板上附着猛水蚤和线虫的数量研究

研究了鲍鱼幼体培育阶段中采苗板上附着猛水蚤和线虫的数量变化。12－2号池猛水蚤的密度为0.02-5.5个／cm^2，平均密度为1.8个／cm^2；12－10号池的猛水蚤的密度为0.01-8.4个／m^2，平均密度为3.0个／cm^2，两个池的猛水蚤都有两个密度的高峰期。采苗板上硅藻的密度变化和猛水蚤的密度的变化有一定关系，显示猛水蚤数量的增加依赖硅藻量的增加和猛水蚤会摄食硅藻。12－2号池线虫的密度为0.02-3.6个／cm^2，平均为个1.5个／cm^2；12－10号池的线虫的密度为0.2-7.0个／cm^2，平均密度为3.2个／cm^2，到幼体培育的中期，两个池的线虫密度都达到最高峰。线虫的密度的增长是依赖于硅藻的密度的增加的。12－2号池鲍鱼幼体密度为0.01-0.45个／cm^2，平均密度为0.15个／cm^2；12－10号池鲍鱼幼体密度为0.01-0.17个／cm^2，平均密度为0.06个／cm^2。在育苗的早期，在采苗板上附着的鲍鱼幼体逐渐增加，以后两个池的鲍鱼幼体密度渐渐降下来。     

太平洋牡蛎高产育苗技术的研究

本文主要从强化亲贝蓄养，加强洗卵和分池孵化工作入手，提高其孵化率，及时选幼；幼虫增减及时筛选不同规格幼虫，投附着基后严格管理等措施来提高其变态率，达到稳产、高产，取得单位水体出苗量平均为３８万多个／ｍ＾３的好效果和明显的经济效益。     

太平洋牡蛎高产育苗技术的研究

本文主要从强化亲贝蓄养，加强洗卵和分池孵化工作入手，提高其孵化率，及时选幼；幼虫培养及时筛选不同规格幼虫，投附着基后严格管理等措施来提高其变态率，达到稳产、高产，取得单位水体出苗量平均为３８万多个／ｍ３的好效果和明显的经济效益。     

石斑鱼鱼虱病的研究：V.盐度对南海鱼虱存活的影响

记述了盐度对南海鱼虱ＣａｌｉｇｕｓｎａｎｈａｉｅｎｓｉｓＷｕ＆Ｐａｎ不同发育影响,在盐度为１０以上时,南海鱼虱的幼虫和成虫对盐度的变化有较大的忍耐性,盐度在１０－４之间对幼虫和成虫存活没有明显的影响,２４ｈ的实验表明,存活率较为１００％,然而,虫卵对盐度的变化较为敏感,虫卵孵化的最适盐度范围为２０－３５,超出此范围虫卵孵化受到影响,当盐度为１０时,虽然孵化率可达１００％,但孵出的幼虫活动能力差,多     

培育密度对大珠母贝受精卵的孵化率及不同期幼虫生长率、成活率与变态率的影响

为了确定大珠母贝(Pinctada maxima)人工繁育过程中受精卵适宜孵化密度和不同发育期幼虫适宜培育密度,设立四组实验比较了培育密度对大珠母贝育苗效果的影响。实验I,比较了受精卵培育密度对孵化率与幼虫大小的影响,受精卵密度设为10个/mL、20个/mL、30个/mL与40个/mL;实验II,比较了D形幼虫培育密度对生长率与成活率的影响,幼虫密度设为1.0个/mL、2.0个/mL、3.0个/mL与4.0个/mL;实验III,比较了壳顶初期幼虫培育密度对生长率与成活率的影响,幼虫密度为1.0个/mL、1.5个/mL、2.0个/mL与2.5个/mL;实验IV,比较了眼点期幼虫密度对变态率与生长率的影响,眼点幼虫密度设为0.4个/mL、0.8个/mL、1.2个/mL与1.6个/mL。结果表明,大珠母贝受精卵培育密度对孵化率存在显著影响(P0.05),对幼虫大小影响不显著(P0.05)。培育密度对D形幼虫与壳顶幼虫的生长率和成活率均存在显著影响(P0.05),生长率与成活率随着密度增加而降低。培育密度对眼点幼虫的变态率和附着幼苗的生长存在显著影响(P0.05)。大珠母贝苗种繁育阶段,合适的受精卵培育密度为10-30个/mL,D形幼虫培育密度为1-3个/mL,壳顶初期幼虫为1.0-1.5个/mL,眼点幼虫为0.4-0.8个/mL。     

紫色无硫细菌对栉孔扇贝幼虫生长发育的影响

于１９９１年，以栉孔扇贝幼虫为材料，用１０００ｍｌ烧杯模拟育菌现场条件，进行光合细菌作为饵料添加剂的试验。分析表明，光合细菌中含粗蛋白６２．３％；１８种氨基酸的总量为５１．２４％；维生素Ｂ１，Ｂ２，Ｂ１２含量分别为０．０１０６５％，０．００９３８８％，０．００２６４％；脂类和其他生理活性物质。生长试验结果表明，在开始的１２ｄ，在补充Ｒｐｓ ｓｐ，５０ｍｇ／Ｌ和１００ｍｇ／Ｌ时，幼虫平均增长率分别为     

虾池纳潮期日本刺沙蚕幼虫数量及其沉降的研究

于1992年2月27日－5月30日在文登市高岛盐场养虾场，对日本刺沙蚕（卵、各期胚胎和幼虫）的纳潮数量和幼虫的沉降进行现场调查和实验研究。结果表明，对养虾生产有意义的纳潮期有3个。3月上旬的新月潮，持续12d，数量为（25－50）×103个／m3，主要组成是受精卵、各期胚胎和担轮幼虫。3月甲旬的满月潮持续7d，数量为（2－5）×103个／m3。4月上旬的新月潮持续8d，数量为（2－3．5）×103个／m3。纳潮量与潮汐关系密切，但与平均潮高无显著的相关。各潮期的纳潮数量比应是4：4：2。对16个纳潮虾池测试的平均沉降量为4492个／m2。据现场调查和实验研究，日本刺沙蚕幼虫的沉降期可划为暂时沉降（5－6刚节）和变态沉降（7—10刚节）。出现暂时沉降（4月15日以后），便可执行纳潮后的排水等虾池早期管理。纳潮的定量监测方法简单、快速和准确，可用来指导虾池的纳潮。     

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.     

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.     

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.     

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.