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1.
南黄海冷水中心内外夏季大型底栖动物群落分析 总被引：4，自引：2，他引：2
根据1959年、2004年和2012年夏季航次的调查数据,研究南黄海冷水中心内、外大型底栖动物群落结构及年际变化。使用Shannon-Wiener多样性指数、Pielou均匀度指数、Margalef丰富度指数,平均分类差异指数以及丰度生物量比较曲线(abundance-biomass comparison curves,ABC Curves)分析群落的组成与变化,使用相对重要性指数(index of relative importance,IRI)分析群落中的优势种和重要种。研究结果显示,3个航次共鉴定大型底栖动物112种,隶属18纲69科80属;其中冷水中心(Yellow Sea cold water mass core,YSCWMC)内33种,隶属16纲65科75属;冷水中心外87种,隶属7纲30科36属。两因素方差分析(Two-way ANOVA)结果显示三航次间时空尺度上冷水中心内、外的H′、J′和d的差异均不显著,物种丰度和物种生物量也未发生明显的改变。冷水中心内部群落的H′、J′和d变化幅度较冷水中心外部群落小,表明相较冷水中心外的群落,冷水中心内的群落结构较为稳定。分类差异变异指数及ABC曲线分析也显示冷水中心内、外的群落状况良好。通过比较冷水中心内、外物种组成发现冷水中心内软体动物(Mollusk)种类最多,其丰度和生物量在冷水中心内优势明显,且三个航次间软体动物物种改变较小。冷水中心内群落中的多毛类动物(Polychaeta)和棘皮动物(Echinodermata)虽在各年份分别占据优势种地位,丰度极高,但种类极少。冷水中心外群落中的多毛类动物和棘皮动物占据绝对优势,无论是种类数还是生物量都较其他种类高。在调查航次总生物量中,冷水中心内的软体动物生物量占总生物量的38%,而冷水中心外的仅占总生物量的3%,说明软体动物较为适宜生活在低温、高盐的冷水环境中。三年间分析调查显示冷水中心内软体动物的重要种及常见种有薄索足蛤(Thyasira tokunagai)、秀丽波纹蛤(Raetellops pulchella)、短吻蛤(Periploma sp.)、胡桃蛤(Nucula sp.)和日本梯形蛤(Portlandia japonica)。冷水中心对于大型底栖动物中软体动物的生长繁殖具有重要的保护作用,能够维持其群落结构的稳定。 相似文献
2.
2OO2年冬季象山港大型底栖生物生态分布特征 总被引：1，自引：0，他引：1
根据拟建的浙江宁海电厂环境评价项目的要求,于2002年冬季对象山港水域大型底栖生物进行了调查,共发现大型底栖生物43种,其中多毛类的种类最多,其次是软体动物和棘皮动物,分别占总种数的44%、26%和21%,全区总平均生物量为103.32g/m2,总平均栖息密度为123个/m2。通过种类相似性聚类和数值多维尺度的分析得出,该区大型底栖生物可划分为5个群落: 为翅状索沙蚕-寡鳃卷吻沙蚕-奇异稚齿虫群落; 为纵肋织纹螺-缩头节节虫群落; 为高骨片沙鸡头-菲律宾蛤仔-凸镜蛤群落; 为棘刺锚参群落; 为洼颚倍棘蛇尾-纵肋织纹螺-黄短口螺群落。群落间的种类和数量呈明显差异。同时,还对影响底栖生物分布的环境因子进行了分析。 相似文献
3.
渤、黄海近岸海域底栖生物生态研究 总被引：3，自引：0，他引：3
对渤、黄海近岸海域底栖生物的种类组成、生物量及栖息密度的分布和群落结构进行了叙述和讨论。结果表明 :渤、黄海近岸海域共获底栖生物 2 39种 ,种类组成以甲壳动物及软体动物占优势 ,为 51 .9% ;底栖生物平均生物量为 56.54g/m2 ,生物量组成以棘皮动物占绝对优势 ,为 41 .6% ;平均栖息密度为 2 64.3个 /m2。按生态特征调查海域的底栖生物可分成 7个群落。分析各测站群落结构指数 ,渤、黄海近岸海域 50 %测站表现出多样性及种类丰度高、种类分布均匀、优势度不明显的特点 相似文献
4.
为了解洞头列岛及邻近海域大型底栖动物的群落结构特征,于2015年4月在该海域布设35个站位进行大型底栖动物调查采样,并获取相关环境资料,分析了该海域大型底栖动物的群落结构及其与环境因子的关系。共鉴定出大型底栖动物122种,其中多毛类57种,甲壳动物34种,软体动物19种,棘皮动物5种,其它类动物7种。各调查站位大型底栖动物物种数目在1~22种之间,瓯江口附近站位物种数较少。大型底栖动物平均生物量为3.35 g/m2,平均栖息密度为321个/m2。多毛类具有种数上的优势,软体动物具有生物量和密度上的优势。Shannon-Wiener多样性指数、Margalef丰富度指数和Pielou均匀度指数的平均值分别为1.29、2.45和0.66。通过聚类分析和多维尺度排序分析将该海域大型底栖动物划分为3个群落:异蚓虫-薄云母蛤-绒毛细足蟹-不倒翁虫群落(群落Ⅰ),薄云母蛤-异蚓虫-双鳃内卷齿蚕-不倒翁虫群落(群落Ⅱ)和其他群落(群落Ⅲ)。典范对应分析表明,影响大型底栖动物群落的主要环境因子有底层海水的温度、盐度、活性磷酸盐、活性硅酸盐、溶解性无机氮、化学需氧量以及表层沉积物中的总有机碳等。ABC曲线分析结果表明,大型底栖动物群落受到了一定程度的扰动,但基本稳定。与历史资料相比,大型底栖动物的栖息密度和生物量均无明显变化,种类组成由以多毛类和软体动物为主转变为以多毛类和甲壳动物为主,且个体较大的棒锥螺大量死亡。 相似文献
5.
舟山朱家尖岛潮间带软体动物生态初步调查 总被引：1，自引：0，他引：1
本文共报道软体动物88种,隶属5纲49科。潮间带软体动物按栖息底质分为三个类型:1.岩礁相:高潮带生物组成为粒屋顶螺群落和短滨螺—粒屋顶螺群落;中潮带为单齿螺—条纹隔贻贝群落、疣荔枝螺—青蚶—单齿螺群落和锈凹螺—疣荔枝螺群落;低潮带为锈凹螺—复瓦小蛇螺群落。2.泥相为珠带拟蟹守螺—婆罗囊螺群落。3.砂相:高潮带与中潮带上层未发现有软体动物分布,中、低潮带的较高潮区为紫藤斧蛤群落,较低潮区为等边浅蛤群落。 潮间带贝类生物量的季节变化规律如下:岩礁相依春、冬、秋、夏递减,泥相依夏、秋、冬、春递减,砂相依冬、秋、夏、春递减。 此外,本文还与中国沿海生物调查作了比较,其生物量与栖息密度的变化规律极为相似。 相似文献
6.
浙江省近岸海域底栖生物生态研究 总被引：5，自引：1，他引：5
对2003年4~5月在浙江省近岸海域底栖生物调查中获得的126种底栖生物的种类组成、生物量及栖息密度的分布和群落结构进行了叙述和讨论。结果表明:底栖生物种类组成以甲壳动物及软体动物占优势,两者占生物总种数的51.6%;浙江近岸海域底栖生物总平均生物量为18.74 g/m2;总平均栖息密度为89.1个/m2。按生态特征划分,调查海域的底栖生物可分成7个群落。分析调查海域各测站群落结构指数可以看出,浙江近岸海域70%测站呈现出生物多样性指数低及种类分布不均匀等特点。 相似文献
7.
本文研究了东山湾潮下带前鳃类软体动物的生态。结果表明,该湾有前鳃类软体动物31科59属86种。其中,分布到黄、渤海的有18种,分布到东海的有59种,只在南海分布的有26种。广温广布种占20.93%,暖水种55.81%,热带种仅5.81%。平均生物量和栖息密度分别为125.37g/m~2和16个/m~2,数量分布不均匀并有明显的季节变化。该湾主要有三个群落:棒锥螺-浅缝骨螺-红带织纹螺群落、假(?)拟塔螺-线缝骨螺-细肋蕾螺群落、细肋蕾螺-假(?)拟塔螺-双带光螺群落。前鳃类软体动物的种类组成、数量分布和群落结构与底质环境关系密切,生物量和栖息密度在粘土质粉砂和粉砂质粘土底质中较高。 相似文献
8.
分析了广东省雷州半岛红树林滩涂底栖生物种类组成与数量分布特点，用Shan non-Wiener多样性指数(H′)、Pielous种类均匀度(J)、种类丰度(D)、Berger-Parker优势度指数(I)4个测定红树林群落种类多样性指标进行数值分析。结果表明，调查所采获的底栖生物种类共有68科165种，种类组成以软体动物和甲壳类动物为主。红树林滩涂全年平均生物量为223．25g／m^2，平均栖息密度为2lO．97个／m^2。H′甚高，2个季度平均为2．2633～2.7411，J平均为0．6407～0．6411，D平均达到1．4910～2．6232。全年各类群生物组成中，生物量及栖息密度以软体动物居首位。红树林滩涂底栖生物主要经济种类有中国绿螂(Glauconome chinensis)、四角蛤蜊(Mactrar Mactra) veneriformis)、青蛤(Cyclinasinensis)等20多种。 相似文献
9.
三沙湾西北部滨海湿地潮间带生物生态研究 总被引：1，自引：0，他引：1
本文报道三沙湾西北部滨海湿地潮间带生物109种,其中多毛类、软体动物和甲壳动物占总种数的89.90%,三者构成潮间带生物主要类群.断面间比较,Sch1断面的种数最少（42种）,Sch3断面的种数最多（73种）.种类季节变化,以春季种数（83种）大于秋季（59种）.三沙湾西北部滨海湿地潮间带生物平均生物量12.45g/m^2,平均栖息密度为368个/m^2.生物量以软体动物居第一位（7.34g/m^2）,甲壳动物居第二位（2.55g/m^2）;栖息密度以软体动物居第一位（196个/m^2）,多毛类居第二位（154个/m^2）.数量垂直分布,生物量以中潮区（15.20g/m^2）大于高潮区（12.37g/m^2）大于低潮区（9.78g/m^2）;栖息密度以低潮区（563个/m^2）大于中潮区（483个/m^2）大于高潮区（56个/m^2）.数量季节变化,生物量以春季（16.69g/m^2）大于秋季（8.21g/m^2）;栖息密度以春季（677个/m2）大于秋季（58个/m^2）.三沙湾西北部滨海湿地潮间带生物按断面和所处的位置可分为3个群落：Sch1泥沙滩群落,高潮区：黑口滨螺-粗糙滨螺带;中潮区：中蚓虫-鸭嘴蛤-秀丽长方蟹带;低潮区：似蛰虫-焦河篮蛤-鸭嘴蛤带.Sch2泥沙滩群落,高潮区：黑口滨螺-粗糙滨螺带;中潮区：才女虫-鸭嘴蛤-淡水泥蟹带;低潮区：似蛰虫-侧底理蛤-鸭嘴蛤带.Sch3泥沙滩群落,高潮区：黑口滨螺-粗糙滨螺带;中潮区：才女虫-鸭嘴蛤-短拟沼螺-弧边招潮带;低潮区：不倒翁虫-侧底理蛤-齿腕拟盲蟹带.结果分析表明：春季Sch1和Sch2群落不稳定,秋季Sch1、Sch2群落和Sch3群落相对稳定,总体显示,三沙湾西北部滨海湿地潮间带生物群落发生扰动,初步分析认为与优势种鸭嘴蛤和优势种才女虫季节演替有关. 相似文献
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大亚湾红树林区底相大型动物的群落 总被引：6，自引：2，他引：6
本文据1987～1989年实地调查资料,研究了大亚湾红树林区底栖生物的种类组成与数量分布。结果表明,分布于湾顶5种红树林内的底栖生物70种,主要由多毛类(23种)、软体动物(23种)、甲壳动物(12种)和星虫动物(8种)组成;平均生物量219.77g/m~2,平均栖息密度281个/m~2;在数量上以软体动物的腹足类占优势。文中应用群落结构指数进行分析,并与九龙江口的作了比较。 相似文献
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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
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
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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.
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. 相似文献
14.
Derek V. Ellis 《Marine Georesources & Geotechnology》2001,19(1):51-63
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.
G. Parthiban 《Marine Georesources & Geotechnology》2000,18(3):223-235
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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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.
Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引：1，自引：0，他引：1
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