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1.
《中国海洋大学学报(自然科学版)》2016,(4)
循环水养殖系统在凡纳滨对虾种虾养殖中应用较少,本研究应用循环水养殖系统养殖凡纳滨对虾种虾,设定4个不同的养殖密度(30、40、50、65尾/m2),初始体重:(0.102±0.008)g,研究凡纳滨对虾种虾在循环水养殖系统中的生长情况。养殖期间定时对对虾体重和水体指标(氨氮、亚硝酸氮、pH、水温、微生物)进行分析测定。通过对各项数据分析表明:低密度组(30、40、50尾/m2)凡纳滨对虾体重增长较快,各组特定生长率分别为(3.83±0.03)%、(3.87±0.01)%、(3.81±0.03)%,绝对增重率分别为(0.201±0.009)、(0.214±0.004)、(0.194±0.009)g/d,但均无显著性差异(P0.05);高密度组(65尾/m2)的凡纳滨对虾体重增长较慢,特定生长率和绝对增重率分别为(3.41±0.02)%和(0.107±0.004)g/d,该结果与低密度组间存在显著性差异(P0.05)。低密度组中凡纳滨对虾养殖水体的水质指标要优于高密度组,4个密度组中氨氮、亚硝酸氮、绿菌均维持在安全浓度范围内,仅仅黄菌数量略高。综合分析,采用该养殖系统养殖凡纳滨对虾的最优密度为50尾/m2。因此,本研究可为循环水养殖系统养殖凡纳滨对虾种虾提供参考。 相似文献
2.
《中国海洋大学学报(自然科学版)》2016,(4)
在凡纳滨对虾养殖水体中使用悬浮絮团发生装置(对照组未使用),设置空白对照组、芽孢杆菌(Bacillus sp.)组、产纤维素酶菌组、共同添加组,检测养殖环境中水质指标、细菌数量和对虾生长指标,评估添加甘蔗渣悬浮颗粒和芽孢杆菌对凡纳滨对虾生长和养殖环境的影响。研究表明:芽孢杆菌组、产纤维素酶菌组、共同添加组的氨氮浓度在实验前期显著低于对照组(P0.05),实验中后期,亚硝态氮浓度显著低于对照组(P0.05),生物絮团含量显著高于对照组(P0.05),说明添加甘蔗渣悬浮颗粒和芽孢杆菌能促进生物絮团的形成,有效降低水体中氨氮、亚硝态氮浓度。芽孢杆菌组、共同添加组水体中芽孢杆菌数量显著大于对照组、产纤维素酶菌组(P0.05);芽孢杆菌组、产纤维素酶菌组、共同添加组的弧菌数量在实验后期都低于对照组,对虾成活率显著高于对照组(P0.05),饵料系数显著低于对照组(P0.05),换水比例较对照组低30%。结果表明:甘蔗渣悬浮颗粒和芽孢杆菌的添加,能增加和维持水体中芽孢杆菌等有益菌的数量,改善养殖环境,促进对虾生长,提高对虾产量,降低饵料系数。 相似文献
3.
《中国海洋大学学报(自然科学版)》2020,(Z1)
为探究定向培育的悬浮生物絮团对凡纳滨对虾(Litopenaeus vannamei)工厂化养殖系统水质环境的影响,分别使用甘蔗渣和稻壳粉搭配芽孢杆菌,在养殖池中培育悬浮生物絮团,以商业养殖模式为对照,进行为期50 d的凡纳滨对虾水泥池养殖实验(放养密度350尾/m~2,初始体长(4.8±0.6) cm,初始体重(1.35±0.48) g);定期检测养殖系统的水质状况、水体和絮团的细菌密度、对虾生长状况。研究表明:甘蔗渣组和稻壳粉组的对虾成活率分别为77.14%和74.11%,与对照组相比分别提高了26.7%和21.7%(P0.05);其产量分别为4.03和3.16 kg/m~2,与对照组相比分别提高了31.7%和3.3%。甘蔗渣组的亚硝态氮和硝态氮峰值分别为2.33和2.27 mg/L,稻壳粉组的亚硝态氮和硝态氮峰值分别为2.20和2.55 mg/L,均较对照组高,且比对照组出现时间早10 d。养殖水体亚硝态氮与硝态氮浓度变动呈极显著线性负相关关系(P0.01),拟合方程分别为对照组y=e~(0.2/x)(R~2=0.966)、甘蔗渣组y=e~(0.364/x)(R~2=0.942)和稻壳粉组y=e~(0.434/x)(R~2=0.945);其亚硝态氮转化为硝态氮的转化速率排序依次为:稻壳粉组甘蔗渣组对照组。研究结果表明:定向培育甘蔗渣和稻壳粉悬浮生物絮团能提升水体的硝化速率,促进亚硝态氮向硝态氮的转化,有利于维持良好的水质环境。另外,甘蔗渣和稻壳粉悬浮生物絮团也有助于提升对虾的成活率和产量,且甘蔗渣悬浮生物絮团对对虾成活率和产量的提升效果优于稻壳粉悬浮生物絮团。 相似文献
4.
微孔管增氧和气石增氧对凡纳滨对虾室内养殖影响的比较研究 总被引：1，自引：0，他引：1
在凡纳滨对虾室内养殖池底部分别铺设微孔管和安装气石,在供氧功率相同的情况下比较微孔管增氧与气石增氧对凡纳滨对虾室内养殖产生的影响.研究表明:在养殖中后期微孔管增氧组的水温低于气石增氧组;从养殖60 d左右到养殖结束微孔管增氧效果明显优于气石增氧;亚硝酸氮、氨氮、非离子氨氮、无机磷与COD含量在2种增氧条件下没有显著性差异(P＞0.05);凡纳滨对虾体重变化、最终产量与成活率在2种增氧条件下没有显著性差异(P＞0.05);凡纳滨对虾血清溶菌酶活力、过氧化物酶相对活力、抗菌酶活力在微孔管增氧条件下较高并达到了显著性差异(P＜0.05);超氧化物歧化酶活力则在气石增氧条件下较高且达到显著性差异(P＜0.05);酚氧化酶活力在2种增氧条件下不存在显著性差异(P＞0.05). 相似文献
5.
投放双齿围沙蚕养殖中国明对虾实验研究 总被引：3，自引：0，他引：3
在养殖中国对虾的围隔内投放不同密度(0kg·m-2,0．4kg·m-2,0．8kg·m-2,1．2kg·m-2)双齿围沙蚕,定时监测水体总氨氮(TAN)、亚硝氮、透明度、DO等指标。实验结束时计量养殖效果。结果表明:总体上,投放沙蚕的处理组对虾产量高于末投放沙蚕的对照组,饵料系数显著低于对照组(p<0．05)．其中0．4kg·m-2沙蚕处理组对虾产量最高[(165．4±8．7)g／m2],水质最佳。随着沙蚕密度增大,国格内TAN、亚硝氮、pH均上升且不稳定,这可能是致使对虾成活率下降的一个原因。投放沙蚕对透明度也有影响。依据实验结果认为,双齿围沙蚕促进了沉积物无机氮向水体释放,进而加速浮游植物的繁殖速率。沙蚕密度过人,可引起对虾成活率下降,建议沙蚕密度控制为0．2～0．6kg·m-2。 相似文献
6.
不同养殖密度对我国热带地区集约化养殖凡纳滨对虾水质和成活率的影响 总被引：2，自引：0，他引：2
报道了在我国热带地区集约化养殖凡纳滨对虾Litopenaeus vannamei不同放养密度下水体pH值、溶解氧(DO)、总碱度(TA)、化学需氧量(COD)、生物化学需氧量(BOD)、硫化氢(H2S)、亚硝酸态氮(NO2-NT)、氨态氮(NH4-NT)及弧菌活菌总浓度(Concentration of Live Vibrio,CLV)的变化特征及其与对虾死亡之间的关系,并比较了70、100、120、150尾.m-2不同养殖密度下的养殖成活率。通过几种主要水质因子变化与对虾死亡数之间的相关性分析,结果表明,DO、H2S、NO2-NT、NH4-NT和CLV等5种水质指标与对虾大量死亡存在显著的线性相关,其中DO为负相关,其余为正相关。而pH、TA、COD、BOD与对虾死亡数无显著相关性。4种养殖密度下的成活率分别为80.44%、75.16%、51.74%和44.43%。建议我国热带地区集约化养殖凡纳滨对虾的合理密度为70—100尾.m-2。 相似文献
7.
凡纳滨对虾(Litopenaeus vannamei Boone),由于其生长快,抗环境变化能力强,对饵料的要求低,肉味鲜美、出肉率高,成为世界上公认的优良养殖对虾品种之一.凡纳滨对虾自1998年从美国夏威夷再次引进到中国华南,并相继突破集约化防病养殖和全人工繁育技术以来[1],已成为中国海水养殖动物中发展最快的一个种类,其养殖产量已达到中国养殖对虾产量的80%～90%.然而目前中国凡纳滨对虾亲虾多数直接从虾塘挑选,造成品质参差不齐,抗病力下降,生产周期延长,严重制约了中国凡纳滨对虾养殖业持续健康发展.凡纳滨对虾亟需形成稳定优良的养殖品系. 相似文献
8.
9.
为探究近海养殖水体溶解性有机质(dissolved organic matter,DOM)的荧光特征及环境指示意义,以山东省东营市凡纳滨对虾池塘为研究对象,利用三维荧光光谱-平行因子分析(EEMs-PARAFAC)技术对2020年9月14日至10月17日凡纳滨对虾池塘养殖水体中DOM的荧光特征进行了分析,以期揭示其来源及环境指示意义。结果表明,养殖池水体DOM有4种荧光组分,包括1种类蛋白质物质(C4)和3种类腐殖酸物质(C1、C2与C3),前者作为养殖池水体DOM特有组分,且其荧光强度高于对照池各组分。养殖池水体DOM总荧光强度、总有机碳和溶解有机碳含量于采样时期均明显高于对照池。综合3种荧光指数(FI、BIX、HIX),对照池和养殖池水体DOM以内源输入为主,自生源特征明显。对照池和养殖池水体DOM组分与营养盐(氮、磷营养盐为主)具有显著相关性,表明DOM组分的产生与利用和营养盐的消耗与生成过程相耦合。养殖池DOM组分C1和C4与chl a呈显著正相关性,表明浮游藻类是养殖水体DOM类蛋白质和类腐殖酸物质的重要来源。该研究揭示了养殖水体有机质高度积累,对养殖环境的富营养化带来潜在威胁,同时为进一步揭示养殖水体DOM的光化学性质提供了科学依据。 相似文献
10.
利用生物控制养殖池污染的研究 总被引：4，自引：0，他引：4
利用陆基围隔对微生物制剂、底栖滤食性贝类、大型藻类控制养殖池污染进行了研究。研究表明,微生物制剂效果明显,利生健浓度达到6mg/L时即可显著降低池塘底泥的自污染速率,底泥中总氮积累速率仅为对照组的45.4%,对虾存活率提高53.25%,并能有效缓解水体中的氨氮压力。底栖滤食性贝类效果不明显,底播密度过大会加快底质的氮污染。菲律宾蛤仔(Ruditapes philippinarum)适宜底播密度为100g/m2,100g/m2处理组水体中的氨氮含量、水体和底泥中的氮积累速率在各处理组中最低,但差异不显著(p<0.05)。结果还表明,江蓠(Gracilaria tenuistip)在池塘中受到微藻竞争、浮泥以及透明度变化影响,生长较差。同时,本文通过对养殖池塘污染物基本概况的初步分析,提出了养殖环境综合治理的初步设想。 相似文献
11.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
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. 相似文献
12.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
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. 相似文献
13.
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. 相似文献
14.
Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
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16.
《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
17.
Hoi-Soo Jung Kap-Sik Jeong Yong-Shik Chu Sung-Hyun Park Ki-Hyune Kim 《Marine Georesources & Geotechnology》2001,19(3):181-195
Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors. 相似文献
18.
Shigehisa Nakamura 《Marine Geodesy》2001,24(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献
19.
This study tests the hypothesis that the in situ void ratio of surficial marine sediments may be predicted from shear wave velocity-depth data with a reliability equal to that of other methods currently available. Shear wave velocity is fundamentally controlled by the number of grain-to-grain contacts per unit volume of material and by the effective stress across those contacts. In this study, three previously established empirical formulae are used to predict void ratio from velocity-depth data. Field data were acquired along a transect off the northern Californian coast across which water depth increased from 35 to 70 m and seafloor sediment type varied from sand to silty-sand, respectively. A towed seafloor sled device was used to collect shear wave refraction data, and a marked, systematic decrease in velocity was observed along the line, ranging from 35-70 m/s for the coarse, near-shore material to 25-40 m/s for the finer, offshore deposits. Void ratios predicted from these velocities were compared with data measured directly from box-core samples. Of the formulae used for prediction, two agree remarkably well with the control data. Both predicted and control values increase from 0.6-0.8 for the sandy material to 1.1-1.5 for the silty-sand. Thus, this study does not disprove the hypothesis set and demonstrates the potential of field shear wave velocity-depth data as a means of delineating spatial variation in void ratio for surficial marine sediments in a remote, nondestructive manner. 相似文献
20.
Particulate samples were collected from the Changjiang river system during a flood period, in May 1997, and POC, stable isotope and lipids associated with particles were examined. Results showed the decrease (0.84% ～ 1.88%) of organic carbon content from the upper reaches to the estuary.δ13C values of particulate organic carbon was in the range of -24.9×10-3 to -26.6×10-3, which were close to the isotopic signature of continental C3 vegetation. Total particulate n-alkanes concentrations varied from 1.4 to 10.1μg/dm3,or from 23.7 to 107μg/g of total suspended matter. Fatty acids were present in all the samples, from 1.4 to 5.4μg/dm3, with saturated and unsaturated straight-chain and branched compounds in the carbon number range from C12 to C30. Both δ13C and the ratio of carbon content to nitrogen content indicate the predominance of terrestrial inputs (soil organic matter) among the particles. The biomarker approach has been used to identify the relative portion of terrigenous and autochthonous fraction in the particulate samples. The distribution of fatty acids suggests a striking phytoplanktonic and microbial signal in most particle samples. The terrestrial alkanes are used to estimate the contribution of terrestrial inputs along the mainstream. 相似文献