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1.
黄海是中国近海生态系统的重要组成部分,蕴藏着丰富的海洋生物资源。本研究利用碳氮稳定同位素技术,对该海域大型底栖动物的食物源、营养级和底栖食物网结构进行了研究。结果表明,底栖动物的食物源悬浮颗粒有机物(POM)、沉积物有机物(SOM)、浮游植物和浮游动物的δ~(15)N平均值为:浮游动物浮游植物SOMPOM,δ~(13)C平均值为:SOM浮游动物浮游植物POM。共测定了54种底栖动物的碳氮稳定同位素,其δ~(15)N值范围为5.81‰(美原双眼钩虾)～14.6‰(黄鲫),δ~(13)C值范围为-21.51‰(日本胡桃蛤)～-8.38‰(司氏盖蛇尾)。软体动物双壳类大多数以SOM和浮游植物作为主要食物来源;软体动物腹足类大多数为以小型软体动物和多毛类为食的肉食性动物;节肢动物蟹类是以POM、SOM、浮游动植物、小型软体动物和多毛类等为食的杂食性动物;节肢动物虾类大多数以浮游动物和端足类等小型甲壳类为食;小型鱼类大多数以浮游动物和小型软甲类为食;大中型鱼类则是以小型鱼类、小型软甲类和小型软体动物为食。本研究中的54种底栖动物的营养级范围为1.20～3.57。其中,双壳类等10种处于1～2营养级,腹足类、蟹类、虾类和小型鱼类等36种处于2～3营养级,大中型鱼类等8种处于3以上营养级。基于大型底栖动物的食物源和营养关系,初步构建了黄海底栖食物网。 相似文献
2.
烟台养马岛潮间带大型底栖动物食物网结构特征 总被引：3，自引：0，他引：3
为探明烟台潮间带主要底栖生物类群间的营养关系和食物网结构特征及其季节性变化,于2019年春季(3月)和夏季(7月)在山东烟台养马岛潮间带采集大型底栖动物、沉积颗粒(SOM)、悬浮有机质(POM)、浮游植物和浮游动物样品。利用稳定同位素技术,对养马岛海滩潮间带底栖生物的碳、氮稳定同位素进行测定和分析。结果表明:大型底栖动物在春季和夏季δ13C和δ15N值分别为?20.23‰—?12.99‰, 5.32‰—10.45‰和?21.91‰—?9.88‰, 7.01‰—14.17‰。夏季的碳、氮稳定同位素数值范围相较于春季均有所增加,相同大型底栖动物物种的碳、氮稳定同位素值会随季节变化而发生变化。春季该潮间带主要大型底栖动物的营养级范围为1.98—3.49,夏季为1.89—4.00。相同大型底栖动物营养级在季节之间无显著变化(P0.05)。营养传递顺序可表达为:滤食性软体动物→多毛类→甲壳动物,与能量流动方向一致。 相似文献
3.
为评价舟山钓梁围垦一期工程对附近海域生态系统的影响,对工程海域水质、浮游植物、浮游动物、底栖动物和潮
间带动物在不同时间的调查数据进行了综合分析。结果表明,工程海域海水处于高度富营养化水平,无机氮和活性磷酸盐严
重超标。围海区内浮游植物细胞丰度在2007 年降到最低,2011 年8 月较2007 年8 月显著增加,均匀度指数呈现相反的变化
趋势。围海工程结束后浮游动物生物量显著降低,浮游幼体在种类数中所占比例增加;大型底栖动物栖息密度、生物量、多
样性指数均显著降低,多毛类种数所占比例增加;潮间带动物栖息密度、多样性指数和均匀度减少。围海造成的海水水质的
变化与浮游植物、浮游动物、底栖动物群落结构参数改变密切相关,海水悬浮物含量是影响浮游生物群落结构的重要因素,
围海工程结束后底栖动物群落结构发生了明显改变。 相似文献
4.
对台湾海峡及邻近海域14种主要经济无脊椎动物的胃含物进行了鉴定分析。结果表明：这些无脊椎动物对饵料生物无明显的选择性，均为混合食性。其食性类型可分为：游泳生物食性类型、游泳动物和底栖动物混合食性类型、底栖生物和浮游动物食性类型、底栖生物食性类型、浮游动物和游泳动物食性类型。10种甲壳动物和4种头足类的营养级范围分别为1．64～2．60级和2．04～2．88级。除周氏新对虾(Metapenaeus joyneri)、角突仿对虾(Parapenaeopsis cornuta)和鹰爪虾(Trachypenaeus curdrostris)属第二营养层次的杂食性动物外，其它的均属第三营养层次的肉食性动物。拥剑梭子蟹(Portunus haanii)、秀斑好(Caarybdis feriatus )、哈氏仿对虾(Parapenaeopsis harduickii)和杜氏枪乌贼(Loligo duvaucelii)的食物生境宽度较大，它们对各种饵料生物的利用更趋均衡。4种头足类之间、3种蟹类之间食物重叠显著。长尾类、短尾类、鱼类和腹足类是台湾海峡主要无脊椎动物营养层次能量传递中的关键功能类群。 相似文献
5.
本文根据2004年长江口及其邻近海域生态调查数据,运用生态通道模型(Ecopath模型)构建生态系统能流网络,分析本区域生态系统营养结构及功能,并与1985—1986年研究数据进行对比,解析两个时期生态系统营养结构与功能的差异。研究结果显示,2004年长江口及其邻近海域生态系统营养级范围为1～4.34,相较于1985—1986年研究结果,底层无脊椎动物食性鱼类和头足类的营养级变动较大。牧食食物链占据主导地位,浮游植物在浮游动物和水母的能量来源中所占比例均在60%以上;碎屑食物链所占能流比为44%。系统总能流为6342.081 t·km–2·a–1。渔获物平均营养级下降,生态营养效率平均值较高,但是碎屑和浮游植物的生态营养效率却明显下降,碎屑趋于累积。生态系统统计量整体显示,长江口及邻近海域生态系统成熟度降低。 相似文献
6.
浮游植物生物量与生产力是海洋生态系食物网的结构与功能的基础环节，是供养其摄食者——浮游动物的物质基础，从而直接或间接地影响海区鱼、虾、贝等经济渔业资源的变动。对浮游植物粒度分级生物量与生产力的研究有助于从更深层次上研究海洋生态系自然群落结构、功能及其环境调控，并可对了解其捕食者群体的特性和营养关系提供重要信息。
渤海是一个半封闭的浅海，生态环境的季节变化显著，同时渤海周围又是人口相对集中，工农业生产较为发达的区域，易受人为因素的影响。20世纪80-90年代初，科学家们曾在渤海进行过不少初级生产力的观测(费尊乐等，1988；朱明远等，1993；吕端华等，1999)，但该海域浮游植物生物量与生产力粒度结构方面的资料尚为欠缺。而近年来渤海生态环境日趋恶化，渔业资源严重衰退，因此在该海域进行生态系统动力学，特别是浮游动物种群动力学的研究时，必须同步开展初级生产力结构的动态变化及其控制过程研究。
本研究是国家自然科学基金重大项目“渤海生态系统动力学与生物资源持续利用”的一个重要组成部分，旨在研究渤海春末、夏初对虾产卵期浮游植物现存生物量和初级产力的粒度结构、周日和空间变化及其与环境之间的关系，特别是浮游动物摄食之间关系，从而为渤海生态系统动力学模式的建立和生物资源的可持续利用提供科学依据。 相似文献
7.
象山港游泳动物群落功能群组成与功能群多样性 总被引：3，自引：0，他引：3
依据2011年4月、7月和11月象山港水域桁杆拖网和单拖网渔业资源定点调查资料,对象山港水域游泳动物群落的功能群组成及功能群多样性特征进行了系统研究。依据摄食习性,本文将调查海域出现的96种游泳动物划分为7个功能群,其中底栖动物/游泳动物食性、游泳动物食性、底栖动物食性和腐屑食性功能群是该水域的优势功能群。相似性分析检验结果显示:不同季节象山港游泳动物群落的功能群结构保持相对稳定,不存在显著性季节差异。4月、7月和11月该水域游泳动物群落的功能群多样性均值分别为1.303、1.261和1.185,亦未呈现显著性季节差异。功能群多样性指数与大个体生物(体重大于50g)的总重量资源密度显著正相关;功能群多样性与物种多样性的关系可用斜率为0.463、截距为0.266的线性方程进行描述,这表明该水域物种多样性的大量丧失可能引起功能群多样性的降低。象山港水域部分功能群所含物种数明显偏少,冗余度较低,在强大的外界干扰下,某些重要物种的衰退可能将使该水域功能群多样性显著降低。 相似文献
8.
9.
南沙渚碧礁生态系营养关系的稳定碳同位素研究 总被引：4，自引：0，他引：4
利用稳定碳同位素分析技术研究了南沙渚碧礁生态系食物网主要生物类群之间的营养关系。结果表明，生物的稳定碳同位素组成与其营养来源有密切关系。浮游植物的δ^13C为-18.3‰，与其所处海域的环境条件一致，浮游动物的δ^13C值变化较大，范围为-20.4‰～-10.9‰,表明可能存在浮游植物和碎屑两种营养来源。珊瑚和砗磲的碳同位素组成（-17‰～-15‰）与浮游动物相差较大，暗示共生虫黄藻可能在这些珊瑚的营养来源中起重要作用。底栖海参（-9.6‰)和蜘蛛螺（-12.5‰)的碳同位不比组成与它们沉积物食性的营养特征吻合。鱼类的δ^13C值变化范围较大（-17.7‰～-10.9‰），未表现出随营养级升高而增大的趋势，说明影响鱼类碳同位素组成的因素比较复杂。 相似文献
10.
浮游生物和大型底栖动物参与水体营养物循环, 影响着污染物的迁移转化与沉积物的稳定性, 对海洋生态系统的能 流和物流起着至关重要的作用。为系统了解渤海海域浮游生物和大型底栖动物多样性与优势种的时空变化状况, 本研究以生 态监测调查结果为依据, 站位重点布设在渤海海域重要的河口、海湾、海岛周边海域以及渤海中部海域, 同时结合相关历史 资料, 对渤海海域的浮游生物和大型底栖动物的种类组成 、密度 、生物多样性指数 、优势种等的变化趋势进行了分析。从 2016—2018 年浮游植物的细胞密度空间分布可以看出, 细胞密度均值在滦河口-北戴河海域相对较高, 而在锦州湾 、莱州湾 和庙岛群岛海域相对偏低。渤海浮游植物多样性在各调查海域之间相差不大, 但渤海湾海域的浮游植物多样性呈现明显的逐 年下降趋势。浮游动物细胞密度在滦河口-北戴河海域相对偏高, 其余各海域差别不大。2016—2018 年, 浮游动物多样性在 双台子河口 、渤海湾 、黄河口海域明显增加, 大型底栖动物群落物种数在渤海湾 、黄河口 、莱州湾和庙岛群岛均呈减少趋 势, 大型底栖动物多样性在锦州湾 、滦河口-北戴河的水平偏低, 在渤海湾有所下降, 耐污能力较强的多毛类成为目前渤海 近岸海域大型底栖动物最主要的优势类群。通过与历史数据对比可知, 2014—2018 年, 渤海浮游植物及浮游动物的群落种 类数、密度 、多样性指数总体变化不大, 主要优势种基本一致, 但大型底栖动物种类数 、生物量和密度总体上呈减少趋势, 主要优势种类由软体动物转变为环节动物多毛类。本研究丰富了渤海海域浮游生物和大型底栖动物群落的研究, 并为渤海生 态系统的健康评价与生物多样性保护提供了数据支持, 对合理开发海洋生物资源具有一定的指导意义。 相似文献
11.
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
12.
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
13.
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
14.
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
15.
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
16.
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
17.
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
18.
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
19.
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
20.