黑鲷和青石斑鱼对气泡幕反应的比较

在室内水池中观察了黑鲷（Ｓｐａｒｕｓｍａｃｒｏｃｅｐｈａｌｕｓ）和青石斑鱼（Ｅｐｉｎｅｐｈｅｌｕｓａｗｏａｒａ）对孔径０．５ｍｍ、孔距５．０ｃｍ，空气压力０．２５ｋｇ／ｃｍ２固定气泡幕的反应。结果表明，气泡幕对两种海水鱼都有显著的阻拦作用，平均阻拦率分别为黑鲷７５．１％、青石斑鱼８２．４％。分析显示，气泡幕对两种鱼的阻拦率间无显著差异。在本实验中，该两种鱼对气泡幕均无明显的适应现象     

气泡幕对黑鲷阻拦作用机制初探

于１９８７年３月－１９８８年１月在室内水池中观察黑铜失去视觉后气泡幕的反应,比较同种参数气泡幕对正常视觉黑鲷与失去视觉黑鲷的阻拦效果,采用大小适宜的红黑双层布将鱼的双眼裹住,使鱼失去视觉,探讨气泡幕对鱼类作用的机制,结果表明,黑鲷失去视觉后,活动受到限制,游泳行为发生变化,游速显著低于正常视觉时,气泡幕对其阻拦率由正常视觉由７５．１％下降到４５．２％下降了３９．８％,ｔ－检验表明,两种视觉状态下的     

扇贝精液超低温冷冻保存技术的研究

于１９９７年３月￣１９９７年５月,取山东长岛和青岛太平角海区的虾夷扇贝和栉孔扇贝,采用自然排放法和解剖法取精液,用自然海水作基础溶液,采用不同的抗并保护剂、冷冻速度、平衡时间,对精子的存活率、受精率和孵 进行了研究。结果表明,两种扇贝的精子以自然海水为基础溶液,加８￣１０％的ＤＭＳＯ作为抗冻保护剂,距液氮表面２５ｃｍ、２０ｃｍ、１０ｃｍ各停留８ｍｉｎ,移入液氮中保存;解冻时,距液氮表面１０ｃｍ、１     

对虾网箱两茬养殖试验

１材料和方法１．１试验海区环境因子　本试验在乐清湾漩门水域进行。网箱泊置海区为泥沙底质，水深１５ｍ，５～１０月份水温１７～３１℃，比重１．００８～１．０１７，海水透明度３００～５００ｃｍ。试验期间海区曾遭受热带风暴潮袭击。１．２网箱结构和规格试验在规格为３ｍ×３ｍ×４ｍ的板框式浮动网箱内进行。箱体为单层聚乙烯网衣结构，用铁锚和沉石固定。网衣网目大小分别是２０目，０．６ｃｍ和１．０ｃｍ网径。１．３养殖措施１．３．１苗种及放苗数第一茬养殖于５月４日将体长０．８～１．２ｃｍ的中国对虾苗２００００尾直放…     

固定气泡幕对许氏平鲉阻拦效果的研究

为探究固定气泡幕对许氏平鲉(Sebastes schlegelii)的阻拦效果,设定气泡幕的孔距、孔径如下:当孔径为0.5mm时,设定孔距为1.0、2.0、3.0、5.0、10.0cm,当孔距为2.0cm时,设定孔径为0.2、0.5、0.8、1.0、1.5mm,研究了这9种类型的固定气泡幕对许氏平鲉的阻拦效果,并探究了许氏平鲉对孔距2.0cm、孔径0.5mm气泡幕的适应性。研究表明:上述各规格的气泡幕对许氏平鲉均有显著的阻拦效果(tt0.01)。在孔距实验中,孔距为1.0、2.0、3.0、5.0、10.0cm的气泡幕对许氏平鲉的平均阻拦率分别为71.43%、95.24%、92.98%、53.85%、80.14%,其中孔距2.0cm的气泡幕阻拦率最高。在孔径实验中,孔径为0.2、0.5、0.8、1.0、1.5 mm的气泡幕对许氏平鲉的平均阻拦率分别为96.03%、95.24%、82.05%、100%、98.74%,其中孔径1.0mm的气泡幕阻拦率最高。在4h的适应性实验中,许氏平鲉对孔距2.0cm、孔径0.5mm的气泡幕表现出一定的适应性(FF_(0.05))。本研究结果可为我国海洋牧场中许氏平鲉鱼群控制技术提供参考。     

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Ｅｎｔｅｒｍｏｒｐｈａ ｓｐ．和网纹藤壶Ｂａｌａｎｕｓ ｒｅｌｉｃｕｌａｔｕｓ。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，年板全年附着量炒２２３４７．１ｇ．ｍ＾－２。     

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。     

紫彩血蛤的生物扰动对沉积物颗粒垂直分布的影响

以玻璃珠作为示踪颗粒,研究底栖双壳类软体动物紫彩血蛤对沉积物的扰动。室内实验的结果表明,在整个实验周期１０ｄ内,沉积物表层的示踪颗粒有４７％向下迁移,最大迁移深度１２ｃｍ,垂直迁移率为１．８０×１０－５·ｇ－１·ｃｍ－２·ｄ－１。沉积物１０ｃｍ深处的示踪颗粒分别有４５％和１５％向上和向下迁移,向上及向下迁移率分别为１．８９×１０－５·ｇ－１·ｃｍ－２·ｄ－１和０．６３×１０－５·ｇ－１·ｃｍ－２·ｄ－１     

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。     

北隍城潮汐,波浪基本特征

北隍城潮汐、波浪特征是：潮汐为正规半日潮，年平均海平面２４２ｃｍ，平均潮差１２７ｃｍ海浪以风浪为主，频率为９９％，涌浪频率为６３％，多年各月平均浪高０．４－１．７ｃｍ周期为３．３－５．４ｓ。     

几种幼鱼曲线游泳能力的比较研究

于１９８９年３－５月，利用视觉运动反应方法测定了黑鲷、黄鳍鲷、鲻鱼、鲤鱼和白鲢５种幼鱼的曲线游泳能力。结果表明，幼鱼游泳速度随环形水道半径增加而加快，但加快的速率逐渐减缓。随游泳时间的延长，游泳速度线性下降，实测耐久时间，黑鲷为６６．７ｍｉｎ；黄鳍鲷为６６．８ｍｉｎ；鲻鱼为１０４．４ｍｉｎ；鲤鱼为７０．３ｍｉｎ；白鲢为５８．８ｍｉｎ。游泳能力指数，黑鲷为２９０．６；黄鳍鲷为１４７．３；鲻鱼为４８５     

气泵法生成气泡帷幕的特性研究

气泡帷幕在水下噪声抑制方面有非常广泛的应用。为了更好地利用气泡帷幕的衰减特性,在实验室水槽设备中采用气泵法产生气泡帷幕,通过对不同深度、气流量接收信号的时频分析,利用共振谱法对气泡分布进行反演。研究表明:(1)气泡的分布可以利用高斯分布近似描述。(2)随着深度增加,气泡含量也有略微增加。(3)气泵法产生的气泡帷幕的气流量大小对衰减的峰值所在的频段基本没有影响,但气流量的改变会影响声波衰减的强弱,气流量大的情况下,气泡帷幕对声波衰减效果更强。通过掌握气泵法生成气泡帷幕中气泡的分布规律,可以有效指导气泡帷幕的设计。     

Acoustic monitoring of gas emissions from the seafloor. Part I: quantifying the volumetric flow of bubbles

Three decades of continuous ocean exploration have led us to identify subsurface fluid related processes as a key phenomenon in marine earth science research. The number of seep areas located on the seafloor has been constantly increasing with the use of multi-scale imagery techniques. Due to recent advances in transducer technology and computer processing, multibeam echosounders are now commonly used to detect submarine gas seeps escaping from the seafloor into the water column. A growing number of en-route surveys shows that sites of gas emissions escaping from the seafloor are much more numerous than previously thought. Estimating the temporal variability of the gas flow rate and volumes escaping from the seafloor has thus become a challenge of relevant interest which could be addressed by sea-floor continuous acoustic monitoring. Here, we investigate the feasibility of estimating the volumetric flow rates of gas emissions from horizontal backscattered acoustic signals. Different models based on the acoustic backscattering theory of bubbles are presented. The forward volume backscattering strength and the inversion volumetric flow rate solutions were validated with acoustic measurements from artificial gas flow rates generated in controlled sea-water tank experiments. A sensitivity analysis was carried out to investigate the behavior of the 120-kHz forward solution with respect to model input parameters (horizontal distance between transducer and bubble stream, bubble size distribution and ascent rate). The most sensitive parameter was found to be the distance of the bubble stream which can affect the volume backscattering strength by 20 dB within the horizontal range of 0–200 m. Results were used to derive the detection probability of a bubble stream for a given volume backscattering strength threshold according to different bubble flow rates and horizontal distance.     

Experimental Investigation of Disturbing the Flow Field on the Vortex-Induced Vibration of Deepwater Riser Fitted with Gas Jetting Active Vibration Suppression Device

An experimental investigation on the disturbance effect of jet-type active vibration suppression device on vortexinduced vibration of deep-sea riser was carried out in the wave-flow combined flume. The vibration suppression device was designed in which the jet pipe was horizontally fixed to the front end of the riser. By varying three different excitation spacings and multi-stage outflow velocities, the influence law of the dominant frequency,dimensionless displacement and other dynamic response parameters was studied under different excitation spacings,and the mechanism and sensitive characteristics of the disturbance suppression were explored. The results indicate that the variation of excitation spacing makes gas curtain enter the strong disturbed flow region at different velocities and angles, and the coupling relationship between excitation spacing and reduced velocity is the key factor to enter the strong disturbed flow region to achieve the optimal disturbance suppression. In the strong disturbed flow region,the influence of gas curtain on the dominant frequency is obviously affected by the flow velocity, while the vibration displacement is stable at the same amplitude and is weakly affected by the flow velocity. Gas curtain can effectively disturb the formation of vortex shedding, destroy the strong nonlinear coupled vibration of the riser, and achieve better vibration suppression effect. In the weak disturbed flow region, the vortex length of the riser tail is prolonged,the strong nonlinear coupled vibration of the riser is gradually restored, and the vibration suppression effect of the device gradually decreases.     

盐度对乌鳢(Channa argus)生长和肌肉品质的影响

设置盐度为0(对照组)、5.0、7.5、10.0的4个水体,饲养平均体重为(402.4±44.6)g的乌鳢30天,测定乌鳢生长性能、肌肉成分、游离氨基酸和肌肉物理性能指标,研究盐度对乌鳢生长和肌肉品质的影响。结果表明,各组乌鳢的增重率分别为37.7%、33.9%、31.5%、6.3%,成活率分别为100%、100%、100%和63.6%,表现出随盐度增加而下降的趋势,但盐度0、5.0、7.5各组间无显著差异,在盐度为10.0的水体中,乌鳢成活率和增重率均显著降低(P<0.05),饲料系数显著增加(P<0.05);随盐度增加,肌肉水分和肌肉失水率增加,而脂肪含量减少;肌肉蛋白含量和胶原蛋白含量在盐度0、5.0、7.5各组间无差异,但在盐度10组显著降低;与对照组相比,盐度7.5组的肌原纤维耐折力增加,肌纤维直径减小;随盐度升高,肌肉质构指标(硬度、弹性、黏性、咀嚼性、凝聚性)均有不同程度改善;在肌肉游离氨基酸方面,随盐度增加,肌肉游离呈味氨基酸和总游离氨基酸含量呈上升趋势,其中盐度10.0组较对照组分别增加88.2%、42.7%(P<0.05)。上述研究表明,适宜的盐度可改善乌鳢的肌肉品质,结合鱼体生长性能,适宜的盐度为7.5。     

杂交鲷和黑鲷幼鱼的代谢率及排泄率比较

杂交鲷是以真鲷为母本,黑鲷为父本的杂交F1代品种,为了比较杂交鲷与黑鲷的代谢特征,采用静水密闭式呼吸仪测定了13、18、23、28、33℃（32℃）5个温度下杂交鲷和黑鲷幼鱼的代谢率及排泄率.结果表明：13~28℃温度下,杂交鲷和黑鲷幼鱼的代谢率、排泄率均随温度的升高而升高,28℃时杂交鲷和黑鲷幼鱼的代谢率、排泄率分别为14.22±0.95、0.39±0.02 J/（g.h）和17.47±0.14、0.43±0.02 J/（.gh）,分别是其13℃时的5.69、4.05倍和4.01、3.73倍;且各温度下黑鲷的代谢率始终高于杂交鲷,前者是后者的1.23~1.73倍;杂交鲷和黑鲷幼鱼分别在32℃和33℃时代谢率比28℃下跌了22.23%和3.83%,证明该温度已分别超出了这2种幼鱼的最高适温;杂交鲷和黑鲷幼鱼28℃时的窒息点溶解氧含量分别为1.94、1.40 mg/dm3,低于真鲷21℃时的窒息点溶解氧含量（2.30 mg/dm3）;O∶N原子比值结果显示,28℃时蛋白质供能比最低,生长积累速度最快,是2种幼鱼的最适温度.综合分析认为,杂交鲷幼鱼具有代谢率显著低于亲本的优点,也继承了父本耐低温的特点,但同时失去了亲本耐高温、耐低氧的特点,并出现了应激反应大等不良性状.     

Site fidelity and movements of gilthead sea bream (Sparus aurata) in a coastal lagoon (Ria Formosa, Portugal)

Short-time site fidelity and movements of gilthead sea bream (Sparus aurata) in a coastal lagoon were determined using passive acoustic telemetry. Nine fish, ranging from 20.1 to 32.5 cm total length, were surgically implanted with acoustic transmitters and monitored for up to 179 days. Minimum convex polygon areas ranged from 18,698.6 m² to 352,711.9 m². Home range sizes were small, with individuals using core areas on a daily basis. However, these core areas shifted within the study site over time towards the opening to the sea. Two different diel behaviors were recorded, with some individuals more active at night and others during day time. Some individuals also demonstrated homing abilities, returning to the capture site after being released more than 4 km away.     

Experimental study on bubble pulse features under the combined action of horizontal and vertical walls

The pulse features of a bubble have a close connection with the boundary condition. When a bubble moves near a rigid wall, it will be attracted by the Bjerknes force of the wall, and a jet pointing at the wall will be generated. In real application, the bubble may move under the combined action of walls in different directions when it forms at the corner of a pipe or at the bottom of a dam. The motion of the bubble shows complex and nonlinear characteristics under these conditions. In order to investigate the bubble pulse features near complex walls, a horizontal wall and a vertical wall are put into the experimental water tank synchronously, and an electric circuit with 200 voltages is designed to generate discharge bubbles, and then experimental study on the bubble pulse features under the combined action of horizontal and vertical walls is carried out. The influences of the combined action of two walls on the bubble shape, pulse period, moving trace and inside jet are obtained by changing the distances from bubble center to the two walls. It aims at providing references for the relevant theoretical and numerical research.