岱山海域大型底栖动物多样性分析

文章利用2015年春季航次(5月)和夏季航次(8月)的大型底栖动物采泥调查资料,对岱山海域大型底栖动物的种类组成、丰度、生物量、优势种、多样性进行分析。主要研究结果如下:春季航次共采得大型底栖动物15种,夏季共采得大型底栖动物22种。类群涉及纽形动物、腔肠动物、环节动物多毛类、软体动物、节肢动物甲壳类、棘皮动物等。其中环节动物多毛类在两个航次中种数均为最高。岱山海域春季大型底栖动物优势种为:不倒翁虫、圆锯齿吻沙蚕、双鳃内卷齿蚕和金氏真蛇尾。夏季岱山海域大型底栖动物优势种类有:不倒翁虫、西方拟蛰虫和异足索沙蚕,其中不倒翁虫是两个调查季度月的共同优势种。岱山海域春季各站位平均丰度22ind./m~2,丰度范围为0~90ind./m~2。夏季各站位丰度范围0~165ind./m~2,平均38ind./m~2。春季各站位湿重生物量范围0~2.65g/m~2,平均0.81g/m~2。岱山海域夏季各站位湿重生物量范围0~16.25g/m~2,平均2.29g/m~2。岱山海域春季生物多样性指数(H′)在0~1.75,平均0.70;夏季生物多样性指数(H′)在0~1.75,平均0.67,季节间差异不明显。     

山东南部近海春季大型底栖动物丰度、生物量及群落结构研究

于2007年4月对山东南部近海进行了32个站位的大型底栖动物研究,共发现大型底栖动物170种,其中多毛类87种,软体动物25种,甲壳类47种,棘皮动物7种,其他类群4种。排名前3位的优势种是背蚓虫(Notomastus latericeus)、东方缝栖蛤(Hiatella orientalia)和寡鳃齿吻沙蚕(Nephtys oligobranchia)。研究海域大型底栖动物总平均丰度为1494 ind/m~2,总平均生物量为13.88 g/m~2,生物多样性指数H′、J′和d的平均值分别为:3.856、0.805和4.004。在30%相似度水平上,该海域大型底栖动物可划分为4个群落。综合H′和ABC曲线的结果,山东南部海域底栖生态环境较好。     

山东半岛南部近海冬季大型底栖动物多样性及群落结构特征

于2006年12月对山东半岛南部近岸海域进行了37个站位的大型底栖动物调查。调查海域共发现大型底栖动物266种,大型底栖动物的总平均丰度和生物量分别为2 373ind./m~2和10.42g/m~2,丰度呈北部高、南部低的分布规律,生物量呈沿岸高、外围海域低的分布规律;调查海域IRI指数居于前10位的种中,多毛类8种,软体动物2种,显示了多毛类在调查海域的优势地位;多样性指数H’表明,调查海域除个别站位外底栖生态环境整体清洁;在23%相似性水平上,调查海域可划分为4个群落,群落呈明显地域性分布;沉积物类型显著影响调查海域大型底栖动物丰度分布。     

洞头列岛及邻近海域大型底栖动物群落结构的研究

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。     

辽东湾六股河口邻近海域冬季大型底栖动物生态学特征

2009-12对辽东湾西部海域进行5条断面15个站位的大型底栖动物调查。共鉴定出大型底栖动物69种,其中纽形动物1种,多毛类31种,软体动物11种,甲壳类25种,棘皮动物1种。优势种有长尾亮钩虾(Photis longicaudata)、日本浪漂水虱(Cirolana japonensis)和长吻沙蚕(Glycera chirori)等。调查海域大型底栖动物平均丰度为955个/m~2,平均生物量为14.0g/m~2。丰度和生物量分布整体呈现离河口越远越高的趋势。在25%相似度尺度上,该海域大型底栖动物可划分为4个群落,各群落受到不同程度扰动。检验得出,底层水环境因子不足以影响大型底栖动物群落结构。     

河北昌黎生态监控区8月份大型底栖动物多样性研究

根据2011-2013年每年8月昌黎生态监控区大型底栖动物监测数据,以Simpson优势度为指标分析了研究区大型底栖动物的物种组成及群落结构年际变化。运用物种多样性指数(H')、均匀度指数(J)、丰富度指数(dMa)深入探究了监控区底栖动物的多样性变化趋势。研究结果显示:1)多毛类、甲壳类、软体类动物是该海域大型底栖动物的主要类群;2)2011-08监控区平均密度为43个/m2,平均生物量为3.14g/m2;2012-08监控区平均密度为41个/m2,平均生物量为3.21g/m2;2013-08监控区平均密度为28.74个/m2,平均生物量为7.72g/m2;3)2013年监控区19个站位多样性指标均值远高于前两年;4)2011-08监控区第一优势种为绒毛细足蟹其Y值为0.029 4;2012-08监控区第一优势种为裸盲蟹其Y值为0.007 3;2013-08监控区第一优势种为长吻沙蚕其Y值为0.007 0。     

秋季山东南部近岸海域大型底栖动物群落特征

2007-10对山东南部近岸海域36个站位进行大型底栖动物的调查。样品共鉴定出大型底栖动物129种,其中多毛类69种、软体动物15种、甲壳类35种、棘皮动物3种,其它类群7种。研究海域内IRI指数排名前3位的是寡鳃齿吻沙蚕(Nephthys oligobranchia)、独指虫(Aricideasp.)和背蚓虫(Notomastus latericeus)。研究海域内大型底栖动物的总平均丰度为932.3个/m~2,总平均生物量为8.2g/m~2。其中丰度的高值区分布于青岛-黄岛海域,低值区分布于日照及乳山湾南部海域,生物量的高值区分布于乳山湾南部-鳌山湾海域,生物量低值区分布于日照-胶南海域。在38%相似度水平上,取样站位可被划分为5个群落。BIOENV分析和RELATE检验结果显示,水深和有机碳质量分数是影响大型底栖动物群落结构的主要因素。     

辽东湾西部海域秋季大型底栖动物的群落结构特征

2009年10月在辽东湾西部海域进行了14个站位的大型底栖动物调查,共发现大型底栖动物99种,其中多毛类44种,软体动物13种,甲壳动物39种,其他类群3种.调查海域内IRI指数排名前十位的种中,多毛类和甲壳动物各占60%和40%,其中前三位的是日本双边帽虫(Amphictene japonica)、二齿半尖额涟虫(Hemileucon bidentatus)和滩拟猛钩虾(Harpiniopsis vadiculus).调查海域内大型底栖动物的总平均丰度为2387.1个/m2,总平均生物量为11.16 g/m2,整个调查海域内大型底栖动物呈现出高丰度低生物量的现状.调查海域内大型底栖动物的香农-威纳多样性指数为0.8881~4.626,平均值为3.556;丰富度指数为1.197~5.474,平均值为3.426;均匀度指数为0.213~0.9248,平均值为0.7714.以40%的相似性尺度,取样站可被划分为5个大型底栖动物站组.通过大型底栖动物多样性分析,本文认为该海域的底栖生态状况良好.     

北黄海獐子岛附近海域大型底栖动物数量分布和季节变化

根据2009年8月~2010年6月4个季度月对位于北黄海獐子岛附近海域所设的13个站进行大型底栖动物生态调查所获得的资料,对该海域大型底栖动物的种数、密度和生物量的组成及季节变化进行分析研究,采用Shannon-Wiener指数(H￠)、物种丰富度指数(D)和物种均匀度指数(J)分析该海域大型底栖动物的物种多样性,并研究该海域的次级生产力、P/B值的空间分布和季节变化。结果表明,北黄海獐子岛附近海域大型底栖动物全年总种数有211种、年平均栖息密度为699.415个/m~2,年平均生物量为98.927g/m~2。各季度的种数(S)、平均密度D(个/m~2)和平均生物量B(g/m~2)的季节变化分别为S_(春季(121))S_(秋季(118))S_(冬季(89))S_(夏季(87)),D_(春季(794.58))D_(秋季(766.92))D_(夏季(674.62))D_(冬季(561.54)),B_(春季(180.271))B_(夏季(107.121))B_(秋季(70.824))B_(冬季(37.493))。全年物种多样性指数H′值、物种丰富度指数D值和物种均匀度指数J值分别为2.976、4.135和0.707。该海域大型底栖动物夏季、秋季和春季的平均密度变化不明显,但冬季明显较少,而平均生物量和种数的季节变化比较明显,春季较高,冬季较低。该海域的平均次级生产力为15.335g(AFDW)/(m~2·a),相对较高。P/B值的平均值为1.239。     

渤海海域大型底栖动物群落及多样性研究（英文）

由于人类城市化进程及工业活动的进一步加剧,其所造成的环境问题及气候变化对于海洋生境产生了不可逆的巨大破坏,海洋大型底栖动物的群落结构及其多样性的研究变得越来越重要,海洋生物多样性的保护成为亟待解决的问题。近年来对于大型底栖动物的研究主要以黄海胶州湾、长江口、福建浙江沿岸海域最为广泛,对渤海大型底栖动物研究显得相对弱化,数据资料时间间隔较长。本文主要综述了渤海湾海域常见大型底栖动物的群落结构和多样性变化及其对围填海工程所导致的环境污染的响应。结果表明,渤海海域大型底栖动物区系相对于其它海区较为简单,已发现大型底栖动物约400余种,优势种主要是低温、广盐暖水种,近五年年均生物量约为19.83 g/m~2,年均栖息密度约为474 ind/m~2,主要是多毛类和软体动物。平均栖息密度季节变化为夏季秋季春季冬季,平均生物量秋季春季夏季冬季。在此基础上对海洋资源的综合开发利用以及生物多样性保护提出了建议。     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

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.     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

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.     

A Review of Some Environmental Issues Affecting Marine Mining

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.     

Increased Particle Fluxes at the INDEX Site Attributable to Simulated Benthic Disturbance

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.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

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。     

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.     

Determination of In Situ Sediment Shear Strength from Advanced Piston Corer Pullout Forces

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.     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

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.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

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.