南澳岛人工放流增殖花蛤

粤东南澳岛发挥内湾滩涂广阔的优势,于1998年10月23日在岛东北端的深澳猎屿湾西南海域,进行了大规模的花蛤人工放流增殖,共放流种苗760多万粒,增殖海区面积2000多亩,为这个海岛县开拓了一条花蛤高产稳产养殖的新路子。     

山东半岛南岸潮汐汊道式海湾海洋环境特征及开发功能探讨

本文以靖海湾、乳山湾、丁字湾为例,论述了潮汐汉道式海湾的自然形态、水文气象、地质地貌之特性,提出要开发利用海湾,首先必须保护海湾,并提出了海湾开发的四项准则:经济效益;促进经济发展的程度;开发项目对国家和地区的重要程度;对环境的影响。据此,靖海湾、乳山湾、丁字湾开发应以港口运输为主,辅以水产生产。     

关于乐清湾对虾人工放流增殖的建议

一、国内外对虾放流增殖简况当今,国内外除人工养殖对虾外,还采取放流增殖,以增加捕捞产量。这既是水产科技重大成果,也是发展近海捕虾业的必由之路。据文献介绍:日本濑户内海70年代初对虾产量仅466吨,由于每年投放虾苗1～1.5亿尾,回捕率为5～10％,我国从1984年开始就进行大规模的对虾生产性放流对虾,据1986年统计:全国沿海共放流对虾苗(3cm)27亿尾使资源迅速增长。到1975年对虾产量上升1230吨。现仍以每年放流3～5亿尾,回捕增殖对虾5000吨,产     

江近海甲壳类资源增殖放流现状研究

甲壳类作为增殖放流的重要组成部分,可以有效地养护、补充自然海域的渔业资源。文章基于2017—2021年浙江省甲壳类增殖放流数据及相关文献资料,系统梳理了甲壳类放流种类与数量、放流资金等的年间变化趋势及放流海域、放流规格的空间、数量分布,结果显示：浙江省2017—2021年甲壳类增殖物种有日本对虾（Penaeus japonicus）、三疣梭子蟹（Portunus trituberculatus）、中国对虾（Penaeus chinensis）等6个种类,共计放流522 045.5万只,投入资金3 320.2万元,其中放流量、投入资金最多的是日本对虾,放流量最少的是拟穴青蟹,投入资金最少的是葛氏长臂虾,放流区域涉及温州、宁波、台州、舟山等市,各区域间的放流布局不平衡,且主要集中在小、中规格。文章将对浙江近海甲壳类放流物种存在的效果评估工作不足、个别增殖物种放流效果不佳、甲壳类放流储备物种少等问题提出针对性建议,以期为今后完善科学的增殖放流管理提供依据。     

大亚湾日本对虾放流技术和增殖效果研究

１９９２年至１９９４年在大亚湾开展了日本对虾Ｐｅｎａｅｕｓｊａｐｏｎｉｃｕｓ的放流增殖研究,以探讨恢复业已衰退资源的可行性,标志放流体长５３－１０９ｍｍ的日本对虾１１１８８尾,生产性放流体长２０－４１ｍｍ的日本对虾苗６４０万尾,放流增殖效果明显,标志放流的回捕率为２．９１％,生产性放流的回捕率为９．３％,大亚湾内放流的日本对虾,不作季节性远距离洄游,只作季节性短距离的浅水－深水区移动。     

胶东半岛南部典型海湾地貌过程对滩涂养殖的响应

应用3S技术和海湾涨/落潮不对称原理,研究了最近40年来胶东半岛南部四个典型潮汐汊道海湾的动力地貌演变,分析了大面积修建养殖池对海湾地貌过程的影响。结果表明,最近30年来4个海湾的海岸地貌类型面积、空间分布格局、地貌类型转换、地貌结构和地貌冲淤状态发生了显著改变。在大面积养殖池被围建以前的1960s年代末到1980s年代初,丁字湾处于涨潮不对称状态但不对称程度增高,乳山湾、五垒岛湾和靖海湾也处于涨潮不对称状态但不对称程度在降低。最近30年来的大面积滩涂养殖池修建,使丁字湾由不断增强的涨潮不对称向落潮不对称状态逆转,使五垒岛湾、靖海湾由涨潮不对称向落潮不对称状态的转化提前,使乳山湾由涨潮不对称向落潮不对称状态的转化延缓。     

胶州湾对虾标志放流回捕率分析

根据在胶州湾东北部，红石崖和黄岛后湾标志放流虾的回捕情况的明显不同，联系到海域的环境特点和幼鲈鱼的分布及中国对虾的习性，讨论了制约放流虾回捕率差异的主要因素；提出了中国对虾放流点应选择在河口，混水，软底质海域。     

天津市渔业资源增殖放流现状及展望（英文）

根据天津渤海水产研究所增殖放流资料,全面总结了天津市自2006来增殖放流工作的成效。天津市自2006年第一次开展以"中国对虾"为龙头的增殖放流活动,迄今为止,增殖品种已达22余种,其中以甲壳类占绝对优势。经过大规模增殖放流,天津市渔业资源增殖放流工作已取得了显著的生态、经济和社会效益。在文章最后,总结了国内外增殖放流的发展趋势,并提出了产业发展需求及发展目标。     

胶州湾中国对虾增殖效果与回捕率的研究

以没有放流幼虾的1987年的河口区仔虾相对数量和8月份幼虾数量比值(109)为系数(a),以ni=axi式(ni是i年自然补充量,x_i是i年河口区仔虾相对数量),估算胶州湾中国对虾有关年份自然补量。将各年8月份幼虾数量(Ni)扣除自然补充量后,再按捕捞系数(k)为0.75,以Ci=(Ni—ni)k/R式估算放流虾的回捕量和回捕率(C)。结果表明,1985,1986和1988—1990年回捕率分别为16.05,11.23,8.49,13.69和17.40％。对虾放流增殖效果显著。     

黄渤海沿岸海湾—溺谷型潮汐汊道的地貌结构

本文以丁字湾等基岩海湾为例，论述了黄渤海沿岸海湾－溺谷型潮汐汊道的地貌结构，尤其着重于口门段深槽及涨、落潮三角洲。认为涨、落潮三角洲的发育状况与入湾河流的供沙量、纳潮水域容量、波浪作用、潮差以及口外海域的开阔程度有关；泻湖型潮汐汊道的落潮三角洲的典型模式可以应用于海湾－溺谷型潮汐汊道，但涨潮三角洲因受基岩海湾的复杂岸线的限制而不能充分发育。本文还讨论了海湾型潮汐汊道与半开敞海湾在动力和形态中的差异     

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.     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.     

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.     

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.     

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.     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.     

《Acta Oceanologica Sinica》Vol. 33(2014) contents

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