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玉环坎门排污口邻近岩相潮间带生物分布特征 总被引：4，自引：2，他引：2
2002年8月对玉环坎门污水处理厂排污口邻近岩相潮间带生物进行定性和定量样品采样,共鉴定出生物57种,其中大型藻类8种、多毛类动物2种、软体动物28种、甲壳类动物13种、棘皮动物1种和其它类动物5种。该排污口邻近两侧岩相潮间带平均生物量为1544.72g/m2,平均栖息密度为3948个/m2。位于排污口左侧的I断面生物量和栖息密度(2406.19g/m2和7415个/m2)明显高于II断面(683.27g/m2和484个/m2),I断面的生物多样性指数(0.91)和均匀度指数(0.39)小于II断面(1.80和0.68);两条断面生物量垂直分布均为中潮区>低潮区>高潮区,I断面栖息密度分布为中潮区>低潮区>高潮区,II断面栖息密度分布为中潮区>高潮区>低潮区。对排污口邻近岩相潮间带生物生态分析表明,该潮间带生物数量的水平分布受海岸开敞度的影响,而垂直分布则与潮区的不同和浪击度的强弱有关。 相似文献
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根据2008年8月至2009年5月4个季度月(夏、秋、冬、春季),对位于石岛大鱼岛村潮间带的高潮区(SD1站)、中潮区(SD2站)和低潮区(SD3站)所设的3个站进行的大型底栖动物生态调查并分析所获得的资料,采用Shannon-Wiener指数(H’)、物种丰富度指数(D)和物种均匀度指数(J)分析该潮间带不同潮区大型底栖动物的物种多样性。结果表明,石岛大鱼岛村潮间带大型底栖动物的总平均栖息密度、总平均生物量和总种数分别为397.7个/m2,99.874 g/m2和68种。3个潮带的平均密度(D)、平均生物量(B)和种数(S)的季节变化分别为:D冬季>D夏季>D秋季>D春季,B夏季>B冬季>B秋季>B春季,S冬季>S夏季>S秋季>S春季。多样性指数H’值大小顺序为低潮区>高潮区>中潮区,D值大小顺序为低潮区>中潮区>高潮区,J值大小顺序为高潮区>低潮区>中潮区;大鱼岛村潮间带物种多样性指数季节性变化不明显。 相似文献
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西门岛红树林区大型底栖动物的群落结构 总被引：20，自引：0，他引：20
浙南乐清湾西门岛红树林区是中国红树林的最北分布地,为研究该区红树林与底栖动物的生态关系,于2004年5月和8月对红树林区大型底栖动物进行现场采样,共发现大型底栖动物42种,其中软体动物20种、甲壳类11种、多毛类5种、其它类6种。平均生物量和平均栖息密度分别为74.26g/m2和340个/m2,软体动物和其它类动物分别占总生物量的43%和39%,它们的栖息密度分别占动物总栖息密度的66%和30%。红树林区底栖动物的特征种为可口革囊星虫Phascolosomaesculenta,在中潮区其生物量和栖息密度分别高达84.33g/m2和304个/m2。该红树林区底栖动物群落结构的分析结果表明:底栖动物种类与红树林发育状况呈负相关、底栖动物生物量与红树林发育状况呈正相关,红树林主分布区(中潮区)底内群落结构较低潮区简单、生物量高、物种多样性低,而无红树林的低潮区则与之相反,生物量低、种间分布均匀、多样性高。多样性指数低潮区(2.44)>中潮区(1.21)>高潮区(1.0);均匀度指数为0.30～0.73,中潮区为最低。 相似文献
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砗磲采挖对珊瑚礁生态系统的破坏——以西沙北礁为例 总被引：1，自引：0，他引：1
《应用海洋学学报》2015,(4)
以西沙群岛北礁为例,通过对比采挖砗磲前后的数据,来说明该活动对珊瑚礁生态系统的破坏.2012~2014年间北礁礁坪上的造礁石珊瑚种类数量变动较大,减少了29种;优势种由之前的鹿角珊瑚(Acropora sp.)变为现在的指状蔷薇珊瑚(Montipora digitata);礁坪的物种多样性指数也处于较低的水平.虽然当前北礁的珊瑚覆盖率为52.83%,但是相比2012年降低了大约10%,尤其是2号站位,珊瑚覆盖率降低了约20%.同时2号站位出现了珊瑚白化死亡的现象.调查结果表明,北礁的珊瑚礁生态系统,尤其是礁坪上的珊瑚礁生态系统已经受到严重的破坏,珊瑚种类减少、群落结构改变、物种多样性降低、覆盖率下降、死亡率提高.通过分析,认为砗磲采挖是造成北礁礁坪珊瑚礁生态系统破坏的一个主要因素. 相似文献
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依据国家海洋环境监测中心2009~2013年测得的数据和资料,对河北昌黎生态监控区潮间带生物的种类组成、栖息密度、生物量、优势种以及多样性指数进行统计运算,分析该监控区5年时间尺度的潮间带生物多样性变化趋势。结果表明:监控区共鉴定出潮间带生物5门,包括节肢动物、环节动物、软体动物、棘皮动物和脊索动物,共17科,26种,类型较少,年际种数呈逐年下降趋势;栖息密度与生物量较低,保持低潮带中潮带高潮带的特征;优势种群变化显著,节肢动物、环节动物和软体动物交替出现,优势种数逐年减少,优势度上升,对其他物种抑制作用增强;均匀度指数(J)呈微上升趋势,变化范围为0.64~0.81,状况良好,物种多样性指数(H′)和丰富度指数(dMa)水平较低,分别为0.81~3.23和0.48~3.96,生物多样性水平呈下降态势。 相似文献
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贝类是海洋底栖生态系统的重要生态类群,在海洋生态系统能量流动和物质循环中起着非常重要的作用,为研究黄河三角洲潮间带底栖贝类群落结构及生物多样性特征,在贝类资源主要分布区分别设置调查断面进行了采样调查和分析。调查共发现贝类22种,隶属于2纲7目17科21属。从丰度来看,各断面季节差异性较大(变化范围在24～3 980 ind./m2),从生物量来看,低潮区>中潮区>高潮区的潮区差异较为显著,低潮区生物量(各断面平均值在945.61～1 091.72 g/m2)远高于其他两个潮区,尤以四角蛤蜊(Mactra Veneriformis)占比最高。优势种包括：四角蛤蜊、文蛤(Meretrix Meretrix)、青蛤(Cyclina sinensis)、托氏■螺(Umbonium thomasi)、光滑河蓝蛤(Potamocorbula laevis)和拟沼螺(Assiminea sp.)等。就各生物多样性指数来看,Shannon-Wiener指数、Pielou均匀度指数和Maglef物种丰富度指数均较低,表明本区域的底栖贝类在物种数量和... 相似文献
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山东半岛宁津沿岸潮间带大型底栖动物生态学研究 总被引：1，自引：0，他引：1
根据2009年11月至2010年8月4个季度(秋、冬、春、夏)对宁津沿岸潮间带2个断面的高潮带(SC1H与SC2H)、中潮带(SC1M与SC2M)和低潮带(SC1L与SC2L)所设6个站位的大型底栖动物生态调查资料,采用种属组成、优势度指数、物种多样性指数、丰富度指数和均匀度度指数等方法,分析了调查区域内大型底栖动物的生态特征和季节变化。结果表明:宁津沿岸潮间带共采集到大型底栖动物45种,其中甲壳动物为优势类群,共计20种;软体动物14种,环节动物多毛类9种,其他类动物2种。优势种组成方面,甲壳动物钩虾类是4个季度的绝对优势种。调查区域大型底栖动物的年平均生物量为45.09 g/m2;最高生物量出现在秋季,最低出现在春季;空间分布上,除春季外其他三个季度的生物量变化趋势均为中潮带低潮带高潮带。年平均丰度为182.67个/m2;最高丰度出现在夏季,最低出现在冬季。宁津沿岸潮间带大型底栖动物的年平均物种多样性指数H′为1.09,季节变化趋势为冬季秋季夏季春季,空间分布趋势为低潮带中潮带高潮带。与邻近潮间带文献资料相比,调查区域的大型底栖动物在物种数量、生物量和丰度、物种多样性方面均处于低值水平。 相似文献
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本文分析了大亚湾潮间带生物数量与分布特点,结果表明,其平均生物量为７３２．８５ｇ／ｍ＾２,平均栖息密度为１２３９个／ｍ＾２,生物量以藻在居第一位,栖息密度以软体动物居首位。岩石、沙滩和红树林泥滩生态相数量比较,生物量以相最高,栖息密度以沙滩最高。数量垂直分布,生物量和栖息密度均为低潮区〉中潮区〉高潮区。 相似文献
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于2009年8月21-22日期间同步调查庙子湖岛和黄兴岛两个岩礁潮间带断面的大型底栖动物种类组成,并分析其群落格局。结果表明,庙子湖岛采集的样品中共有4门28种大型底栖动物,黄兴岛的则有5门37种大型底栖动物;两断面底栖动物群落以广温广布种和亚热带种为主,软体动物作为绝对优势类群主导其分布特征;总平均栖息密度、总平均生物量表现为庙子湖岛＞黄兴岛,种类数及生物量分布均表现为中潮带＞低潮带＞高潮带,栖息密度分布则表现为中潮带＞高潮带＞低潮带;物种多样性指数和物种丰富度指数均为黄兴岛＞庙子湖岛,两断面高潮带的群落生态指数相对中、低潮带较低;大型底栖动物ABC曲线分析表明,庙子湖岛底栖动物群落未受到污染或扰动,黄兴岛底栖动物群落则受到了中等程度的污染或扰动。 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
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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
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Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges. 相似文献
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A vertically integrated model has been used to study the tidal circulation and currents in the Gulf of Kachchh along the west coast of India. The model is fully nonlinear and uses a semiexplicit finite difference scheme to solve the basic hydrodynamic equations on a staggered grid. The model is forced by prescribing the tides along the open boundary of the model domain. The flow is simulated both with and without the presence of the proposed tidal barrage across the Hansthal Creek in the Gulf of Kachchh. The results show a considerable change in the behavior of the tidal flow in the presence of the barrage. 相似文献
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利用中国GF-3卫星SAR和HY-2A卫星微波散射计的首次台风联合定量观测 总被引：4，自引：0，他引：4
<正>The typhoon,as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall,is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia.It can be easily detected by space-borne sensors operated at microwave,visible or infrared bands(Liu et al.,2014).Synthetic Aperture Radar(SAR)is 相似文献
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Soil core samples fromRhizophora mangleL. andAvicennia schauerianaStapf & Leech forests from south-eastern Brazil were analysed for their total organic matter content and their sugars, amino acid and amino sugars composition. Organic carbon and nitrogen contents were higher inAvicenniathan inRhizophorasoils. The contribution of sugars and amino acids to the total organic carbon pool was constant with depth inRhizophorasoils whereas inAvicenniasoils it increased. Spectral distribution of sugars and amino acids showed a dominance of Ca-affine monomers, particularly acidic amino acids, and the sugar arabinose. Biogeochemical indicators derived from ratios of individual sugar and amino acid monomers confirm previous studies which showed that organic matter in both soils is mainly of mangrove origin. The results further suggest accumulation of organic matter inRhizophorasoils and a continuing degradation of organic matter inAvicenniasoils. The latter may thus release more nutrients to adjacent ecosystems thanRhizophorasoils. 相似文献
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《African Journal of Marine Science》2013,35(1):181-203
Orange roughy Hoplostethus atlanticus are unusual fish. They form dense aggregations that have fuelled lucrative fisheries at great depths (600–1 400 m), especially off Namibia, New Zealand and Australia. They are thought to be very long-lived (>100 years, maturity at 22 – 40 years), and to have exceptionally low natural mortality (M = 0.045–0.064 year?1) and slow growth rates (K = 0.055–0.070 year?1). In addition, they spawn large eggs and have low fecundity. These factors combine to make orange roughy highly susceptible to overfishing; most stocks are below 30% of pristine levels. Assessments are obtained from indices of catch rate and trawl, acoustic and egg surveys. Acoustic estimates are the most direct, but are confounded by the species' low target strength (?50 to ?53 dB)–attributable to the wax-filled swim bladder. Extracellular wax esters are stored in abundance and comprise mostly mono-unsaturated fatty acids, with low concentrations of the ω-3 fatty acid family. This unusual composition (resultant from the species' diet) ensures neutral buoyancy. Stock separation has been inferred mainly from biological studies, but genetic studies have also found differences among stocks within New Zealand and Australia. Deep-water habitat may be damaged by trawling operations and may take many years to recover, so in some quarters there is a call for a portion of suitable habitat to be set aside for preservation. Although Namibian orange roughy are shallower, smaller and younger than those in other stocks, the Namibian fishery sustained high catches for only a few years before quotas were reduced, from 12 000 to 1 875 tons. Three management lessons are suggested for developing orange roughy fisheries based on the Namibian experience: (1) imposition of catch limits during exploratory fishing; (2) starting the acoustic surveys earlier in the fishery, if possible; (3) greater reliance on trends in catch rate until a survey series has been established. 相似文献