红树蚬的生态观察

１９９１年４月－１９９３年８月，对广东，广西，海南的红树蚬Ｐｏｌｙｍｅｓｄａ ｅｒｏｓａ（Ｓｏｌａｎｄｅｒ）的生态环境，生活习性与分布等进行了观察。红树蚬分布于热带－亚热带海区，生活在咸淡水交汇的河口和潮间带，生长量适的水温２０－２８℃，盐度５－２０，海水ＰＨ７．２－８．２，底质为软泥，泥砂或砂泥，栖息深度约１０ｃｍ，以底栖硅藻和有机碎屑为食，繁殖期为５－９月。其肉供食用，药用，可发展人工养殖。     

南麂列岛海域微小型底栖藻类生态研究

本文首次报道南麂列岛海域沉积物中的微型（２～２０μｍ）、小型（２０～２００μｍ）藻类组成、数量分布及其与环境因子的关系。经初步鉴定，沉积物中共有微小型藻类２４属７１种，其中小型的底栖圆筛藻属Ｃｏｓｃｉｎｏｄｉｓｃｕｓｓｐｐ．为２１种，广布于整个海区，春季平均细胞密度为（１０．４±３．６）×１０３个／ｃｍ２，占总密度的６５．４％；微型藻以中肋骨条藻Ｓｋｅｌｅｔｏｎｅｍａｃｏｓｔａｔｕｍ占优势，秋季平均细胞密度为（４２６２．８±１１９２８．２）×１０３个／ｃｍ２，占总细胞密度的９８．９％，主要分布在沿岸区。对０～１２ｃｍ柱状样品中细胞密度分层分析结果表明，０～２ｃｍ层的细胞密度大于２～５ｃｍ层大于５～１２ｃｍ层。沿岸区（１，２，５，６，７，８，９站）的种类和细胞密度高于岙口（３站）、远岸（１０站）及水道区（４站）。根据微小型底栖藻类组成特点，可划分为三个生态类群：广布性类群、暖水性类群和温带性类群。微小型底栖藻类密度与营养盐浓度的季节变化密切相关，秋季高于春季。     

大连湾水域浮游桡足类的分布

本文根据１９８２年４月至１９８３年５月在大连湾周年生态调查中获得的资料，分析了大连湾浮游桡足类的数量分布和季节变化。结果表明，大连湾共有浮游桡足类２２种，其中优势种大网为中华哲水蚤Ｃａｌａｎｕｓｓｉｎｉｃｕｓ；中网为小拟哲水蚤Ｐａｒｕｃａｌａｎｕｓｐａｒｖｕｓ、拟长腹剑水蚤Ｏｉｔｈｏｎａｓｉｍｉｌｉｓ、短角长腹剑水蚤Ｏｉｔｈｏｎａｂｒｅｖｉｃｏｒｎｉｓ。桡足类总量年高峰，大、中同各有２次，最高峰分别为２月和８月。本文还讨论了几种环境因素对浮游桡足类分布的影响。     

日本对虾卵巢促熟技术研究

利用卵巢未发育的海捕日本对虾Ｐｅｎａｅｕｓｊａｐｏｎｉｃｕｓ，采用综合措施，进行切除眼柄前、后两个阶段培育，促进卵巢发育和成熟。结果：切除眼柄前分别在ｔ＝１５．０—１８℃和２０．０─２３．０℃经１７ｄ左右的培育，卵巢发育率为６２％—６５％；切除眼柄后在ｔ＝２５．０—２５．５℃经４—５ｄ的培育，亲虾成批成熟和产卵，成熟率为９６％。先后两批共育出了３０２０万尾苗种。     

渤海中部铅直扩散系数的探讨

根据Ｋｕｌｌｅｎｂｅｒｇ的半理论半经验公式，利用渤海中部８号平台的观测资料，选择强风期的２月和弱风期的７月分别代表冬季和夏季，推算了渤海中部海域冬、夏两季的铅直扩散系数。计算结果表明：Ｋｚ值在强风期的２月最大可达５．５ｃｍ２／ｓ；在弱风期的７月跃层中可达０．０２～０．０４ｃｍ２／ｓ。     

湛江港污损生物挂板试验

１９９１年４月至１９９２年３月在湛江港内的试验浮筏上进行了污损生物周年挂板调查。共记录５９种生物。优势种是浒苔Ｅｎｔｅｒｍｏｒｐｈａｓｐ．和网纹藤壶Ｂａｌａｎｕｓｒｅｔｉｃｕｌａｔｕｓ。表层月板附着量变化幅度１０．０—２５０．０ｇ·ｍ－２，底层月板附着量变化幅度为３．０—５６８０．５ｇ·ｍ－２，年板全年附着量为２２３４７·１ｇ·ｍ－２。     

福建西洋岛海域浮游植物的分布

鉴定分析了于１９９０年５、８、１１月和１９９２年２月采自福建西洋岛海域的７２份样品。记录浮游植物１２７种，其中蓝藻１种、硅藻１０５种、甲藻２０种、金藻１种。浮游植物月平均细胞总量为５１．４２×１０＾４个／ｍ＾３。其年高峰出现于夏季８月，达１３７．０５×１０＾４个／ｍ＾３，低谷出现在冬季２月，仅有６．９６×１０＾４个／ｍ＾３。     

虾池小型底栖动物的数量研究

提出１９８７年５月至１０月在黄岛养虾池对虾生长周期内对小型底栖动物数量逐月调查。指出：小型底栖动物总平均密度为１０９２．４ｉｎｄｓ·１０ｃｍ－２，自由生活海洋线虫和底栖桡足类是主要类群，其总平均密度分别为４６６．９和４５７．９ｉｎｄｓ·１０ｃｍ－２。８９．７％的小型底栖动物分布在沉积物表层２ｃｍ内。结果指明小型底栖动物被对虾捕食，并提出了捕食模式。     

光合细菌在对虾育苗生产中的应用

１９９５年４月２４日～５月８日，在文登高岛盐场育苗场５０ｍ３水体育苗池，进行了用几株光合细菌（ＲｈｏｄｏｐｓｅｕｄｏｍｏｎａｓＳ．Ｐ．）混合菌液作为中国对虾（Ｐｅｎａｅｕｓｃｈｉｎｅｎｓｉｓ）苗期水质净化剂及辅助饵料，取得了明显效果。育苗池水透明度提高约２０ｃｍ，幼体挂脏率下降５０％，变态提早１ｄ左右，且多产仔虾百万尾     

海水池塘施肥混养滤食性鱼贝的初步研究

实验于１９９５年７月１０日至９月１６日,在烟台市黄海水产集团公司第二养虾场进行。采用围隔生态系实验法,利用４个海水池塘陆基围隔（５ｍ×５ｍ）初步研究了台湾红罗非鱼（Ｏｒｅ－ｏｃｈｒｏｍｉｓｍｏｓｓａｍｂｉｃｕｓ×Ｏ．ｎｉｌｏｔｉｃｕｓ）与菲律宾蛤仔（Ｒｕｄｉｔａｐｅｓｐｈｉｌｉｐｐｉｎａｒｕｍ）施肥混养的效果。结果表明：菲律宾蛤仔的生产力为１．２４ｇ／ｍ２·ｄ,负荷力为３８３０．０ｋｇ／ｈｍ２;罗非鱼的生产力为１．８６ｇ·（ｍ２·ｄ）－１,负荷力为１５８０．８ｋｇ／ｈｍ２。鱼贝对施入氮、磷的利用率分别为１５．０６％和６．８０％,比单养罗非鱼要高;总生产力和总负荷力都明显高于单养罗非鱼。     

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.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics.