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1.
海水池塘混合施肥养殖台湾红罗非鱼的鱼产力和负荷力   总被引:2,自引:0,他引:2  
于1995年7—9月,在烟台市黄海水产集团公司第二养虾场,采用围隔实验法研究了海水池塘混合施肥养殖台湾红罗非鱼的鱼产力、负荷力和最适放养量。实验中每个围隔面积为 5m×5m,各设 1台 90W的搅水机(4 800r/ h)。每日施肥基准为:鸡粪干物质, 25kg/ha:氮肥, N0.15× 10-6;磷肥,P0.015× 10-6。结果表明,静水海水池塘混合施肥的鱼产力为0.79g/(m2·d),池塘对台湾红罗非鱼的负荷力为1796.0kg/ha,鱼(体重70g/ind)的最适放养量约为8000ind/ha。  相似文献   

2.
紫彩血蛤的生物扰动对沉积物颗粒垂直分布的影响   总被引:3,自引:3,他引:0  
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  相似文献   

3.
黄、渤海几种海产无脊椎动物蛋白质与氨基酸含量分析   总被引:13,自引:1,他引:13  
三疣梭子蟹(Portunus trituberculatus)、虾蛄(Squillaoratoria)、刺参(Stichopus japonicus)、海地瓜(Acaudinamolpadioides)、脉红螺(Rapana venosa)、长竹蛏(Solengouldii)、泥蚶(Tegillarcagranosa)、菲律宾蛤仔(Ruditapesphilippinarum)、紫贻贝(Mytilus edulis)、长蛸(Octopusvariabilis)、马粪海胆(Hemicentrotu…  相似文献   

4.
金属离子对牙鲆仔鱼的毒性影响   总被引:4,自引:0,他引:4  
本文用静水生物实验法进行了Zn、Cu、Pb、Cd金属离子对海洋底栖鱼类牙鲆(Paralichthysolivaceus)仔鱼的成活影响研究。结果表明:Cu(2+)、Cd(2+)、Zn(2+)、Pb(2+)对牙鲆仔鱼24hLC(50)分别为1.14、1.51、4.68、5.89mg/dm3.48hLC(50)分别为0.14、0.83、0.99、3.47mg/dm3.72hLC(50)分别为0.06、0.36、0.71、0.93mg/dm3.96hLC(50)分别为0.02、0.14、0.43、0.53mg/dm3.Cu(2+)对牙鲆仔鱼的毒性最大,Pb(2+)的毒性最小.4种金属离子对仔鱼的毒性顺序依次为:Cu(2+)>Cd(2+)>Zn(2+)>Pb(2+).  相似文献   

5.
厌氧接触消化技术处理高浓度淀粉废水研究   总被引:1,自引:0,他引:1  
实验采用厌氧接触消化技术,分别在中温(32℃)和自然温度条件下处理淀粉厂的高浓度废水。结果表明,采用中温厌氧消化可取得较好的处理效果,原水不调pH(原水pH为4.0~4.9)直接进反应器,容积负荷最高达5.06kgCODcr/m3·d,进水CODcr平均11.604×103mg/l,出水CODcr平均1.778×103mg/l,CODcr去除率达85.8%,出水pH提高到6.4~7.0。采用自然温度消化,当气温大于24℃时,可取得较好的处理效果  相似文献   

6.
本文根据经济贝类污染物残留量调查结果,对辽宁沿岸海域贻贝、菲律宾蛤仔作为重金属、石油污染的生物指示种的可能性进行了初步研究和评价。应用POLYDIV统计技术对采自辽宁沿岸海域14个站点样品中的重金属、石油含量进行了统计分析,结果表明辽宁沿岸海域各站点的贻贝、菲律宾蛤仔受Cu,Zn,Cd,Hg和石油污染与石油污染程度的分布和沿岸排放工业废水的分布及表层沉积物中的含量相一致。据此,贻贝和菲律宾蛤仔可作为监测Cu,m,Cd,Hg和石油污染的生物指示种;可否作为Pb的生物指示种尚需进一步研究。  相似文献   

7.
空间因子分析与沉积地球化学旋回元素组合的确定   总被引:1,自引:0,他引:1  
1995年5月,引用地矿部“七五”东北太平洋CCA121柱状沉积物的8个元素地球化学分析数据,利用空间因子分析方法确定两种周期度(D1=65cm,D2=105cm)内的沉积地球化学旋回元素组合,并据此探讨多金属结核成矿与物源环境的关系,研究表明,与小尺度周期(D1=65cm)对应的元素组合:Ud1(Mn,Co,Cu,Al2O3,SiO2和Ud2(Fe,Ca,Co,Cu)与大尺度周期对应的元素组合为  相似文献   

8.
虾蛄的人工养殖技术研究   总被引:7,自引:0,他引:7  
1998年5月1日~7月16日在浙江宁波大学水产苗种试验场进行了不同虾蛄种类,不同换水量,不同放苗规格、数量的养殖试验。结果表明:黑斑口虾蛄Oratosquilakempi比口虾蛄O.oratoria生长快、成活率高;水质条件较佳的塘,虾蛄生长迅速,平均每10天体长增加1.4cm,产量达804.0kg/hm2。  相似文献   

9.
本文在σ坐标下建立了一个半诊断计算及预报计算的数值模式,应用于台湾海峡夏季时三维海流计算。计算结果表明,当t=2.5d时,密度场和速度场得到调整,即得到半诊断解,当t=40d以后,解已达到准稳定态;半诊断及预报计算的结果在定性上是与诊断计算结果一致。但它们在定量上有些变化,如表层台湾岛西岸附近的最大水平流速,在t=0时(诊断)为59.1cm/s,t=2.5d时(半诊断)为62.1cm/s,t=300d时(预报)为62.0cm/s.此外,在半诊断及预报计算中,上升流也主嵰⑸诟=ń兜龋魉偌忧浚段б灿兴┐蟆  相似文献   

10.
张Cai 《海洋通报》1997,16(5):66-70
从合浦珠母贝Pinctada fucata (Gould)和刁海龙Solenognathms hardwichi(Gray)中提取而制成的龙珠液,给大鼠灌服(0.75、1.50、2.25g.kg^-1)可显著抑制由高脂食物诱发的高脂血症;给小鼠灌服(2.25、3.75g.kg^-1)可显著增强其对异物颗粒的廓清能力,增高淋平细胞化的转化率,增加前列腺贮精囊的重量。  相似文献   

11.
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.  相似文献   

12.
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。  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

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18.
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.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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