泉州湾北岸潮间带大型底栖生物群落研究

2014年9月和2015年5月,分别在泉州湾北岸布设3条潮间带断面进行大型底栖生物群落研究.共计采获潮间带大型底栖生物样品166种,其中泥沙滩有80种,岩相有96种.其中环节动物、软体动物和节肢动物有145种,构成该区域潮间带大型底栖生物的主要类群,调查的3条断面中,泥沙滩断面的平均栖息密度和生物量分别为133 ind./m~2和24.48 g/m~2,岩相断面的平均栖息密度和生物量分别为1 412 ind./m~2和958.78 g/m~2.数量垂直分布,泥沙滩断面和岩相断面平均栖息密度和生物量均以中潮区低潮区高潮区.数量季节变化,泥沙滩断面平均栖息密度和生物量均为春季(170 ind./m~2和32.04 g/m~2)大于秋季(96 ind./m~2和16.92g/m~2),岩相断面平均栖息密度为春季(1 360 ind./m~2)小于秋季(1 464 ind./m~2),而平均生物量为春季(1 122.83 g/m~2)大于秋季(794.75 g/m~2),数量季节变化显著.丰度/生物量曲线显示,泉州湾北岸潮间带大型底栖生物群落群落结构较为稳定,受到干扰较小.     

大亚湾红树林区底相大型动物的群落

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。     

渔山列岛夏季潮间带大型底栖生物群落结构研究

于2014年8月,在浙江宁波渔山列岛布设4个岩礁断面开展潮间带大型底栖生物调查,分析其种类组成、丰度、生物量、优势种、生物多样性和群落结构特征等。该调查共采集到潮间带大型底栖生物98种,包括大型底栖动物70种和大型底栖藻类28种;其中优势种有9种,分别为小结节滨螺[Echinolittorina radiata(Souleyet)]、条纹隔贻贝[Septifer virgatus(Wiegmann)]、厚壳贻贝[Mytilus coruscus(Gould)]、带偏顶蛤[Modiolus comptus(Sowerby)]、栗色拉沙蛤[Lasaea nipponica(Keen)]、日本笠藤壶[Tetraclita japonica(Pilsbry)],刺巨藤壶[Megagbalanus volcano(Pilsbry)],以及珊瑚藻[Corallina officinalis(Linnaeus)]和小石花菜[Gelidium divaricatum(Marteus)]。潮间带大型底栖生物平均生物量为8 515.50 g/m~2,平均丰度为6 841.63个/m~2;各断面Shannon-wiener指数(H′)、Pielou均匀度指数(J)和Margalef丰富度指数(d)平均值分别为1.89±0.14、0.38±0.01和3.66±0.52。ABC曲线分析表明,4个断面受到一定扰动。与历史资料相比,该区域物种数减少明显,生物量和丰度有所增加,优势种被个体较小的日本笠藤壶、条纹隔贻贝等物种所演替。上述结果可为渔山列岛潮间带开发保护管理及其生物资源的可持续利用提供重要参考。     

福清核电站邻近潮间带大型底栖生物数量分布与群落结构

于2006年2、4、7和10月在福清核电厂运行前对其邻近潮间带不同底质断面的大型底栖生物进行采样,以了解该潮间带大型底栖生物的种类及资源分布.结果表明,该核电站附近潮间带大型底栖生物总共为146种,以多毛类、软体动物和甲壳动物为主.以季节和底质为因素对取样获得物种数进行双因素方差分析显示:种类获得数的季节变化无显著差异,底质间呈边缘性显著.4季的大型底栖生物平均生物量为1 446.11 g/m2、平均栖息密度为972个/m2.大型底栖生物生物量平均值为春季＞夏季＞冬季＞秋季,栖息密度平均值为夏季＞春季＞冬季＞秋季.以季节和底质为因素的双因素方差分析显示:大型底栖生物生物量和栖息密度季节间无显著差异但底质间差异极显著.底质和季节间大型底栖动物的Shannon-Weiner指数、Margalef种类丰度、Pielou均匀度和Simpson优势度指数均无显著差异.利用Bray-Curtis相似性聚类对福清核电站邻近潮间带大型底栖生物进行分析后得出,该潮间带大型底栖生物可划分为两个群落:岩礁群落和泥沙滩群落.分析表明,底质是影响大型底栖生物分布的主要环境因子,季节对大型底栖生物分布的影响不显著.     

拟建宁海电厂附近潮间带底栖生物群落生态

2002年12月对拟建宁海电厂附近海域3条潮间带断面的底栖生物生态进行了调查,共鉴定出潮间带大型底栖生物71种,平均生物量为1753.92g/m2,平均栖息密度为839个/m2。生物多样性指数和K-优势曲线都显示了位于拟建电厂选址区内的潮间带底栖生物群落已经受到了扰动。     

硇洲岛潮间带不同生境底栖软体动物物种多样性研究

对硇洲岛潮间带（岩石、砾石、泥沙滩）3种不同生境的11个样方的底栖软件动物进行了生物多样性调查，共鉴定底栖软体动物21科41种。研究结果表明，硇洲岛潮间带底栖软体动物动物种丰富度指数砾石滩最大（平均为9.236)，岩石滩次之（平均为6.494)，泥沙滩最小（平均为3.788)，多样性指数砾石滩（平均为2.154)大于泥沙滩（平均为1.506）大于岩石滩（平均为1.334)。对上述样方进行聚类分析的结果表明，底栖软体动物的种类及数量分布受底质、浪击、污染等因素的影响。     

胶州湾中部海域大型底栖生物生态学初步研究

2006年8月～2007年10月分4个航次对胶州湾中部海域进行大型底栖生物调查。调查结果表明,大型底栖生物总平均丰度和总平均生物量为1507个/m~2和35.88g/m~2。与历史资料做了对比,并初步分析了与以往调查结果不同的原因。调查海域大型底栖生物多样性指数和丰度生物量比较曲线显示,胶州湾中部海域底栖生物处于轻微扰动状态。     

厦门西港底栖生物的生态

本文根据1980年11月和1981年2,5,8月在厦门西港调查的底栖生物资料,研究了本区底栖生物的生态特点。结果表明,本区底栖生物333种,主要由多毛类、甲壳动物和软体动物组成;其平均生物量46.53g/m~2;平均栖息密度699个/m~2,这两者分布很不均匀,季节变化明显;环境质量和水动力是影响本区底栖生物分布的主要因子。     

不同孔径筛网对底栖多毛类采样效果的研究

本文根据大亚湾50个站底栖生物生态调查资料,对孔径1mm和0.5mm筛网中多毛类的种类数、主要种、平均密度、平均生物量进行比较分析。结果表明,孔径1mm的为14种/站、9种、110个/m~2和8.03g/m~2,而0.5mm为22种/站、12种、216个/m~2和0.71g/m~2;1mm筛网多毛类密度(X)与0.5mm的密度(Y)呈线性正相关关系,其回归方程为:Y=0.93X+113.77;在估算海域生产力中,应当使用0.5mm孔径筛网。     

珠江口东南部海域大型底栖生物群落特征研究

根据2006年的3月和7月在珠江口东南部海域进行的大型底栖生物调查,初步鉴定出大型底栖生物共156种,其中多毛类种类最多(79种),其次是甲壳动物(37种)。7月(116种)比3月(92种)种类多。3月大型底栖生物平均生物量和平均密度分别为6.703g/m2和679.4ind/m2,7月分别为22.436g/m2和576.3ind/m2。大型底栖生物种类数、生物量、密度和多样性指数(H’和J’)在调查海区东南部相对较低。采用Bray-Curtis相似性系数聚类分析和多维排序尺度(MDS)分析了3月和7月大型底栖生物群落的相似性,认为相同季节各站大型底栖生物相似性系数较高,大型底栖生物群落季节性差异相对较大。大型底栖生物群落在40%相似性以上,3月和7月分别可以划分出2个和3个生物群落。3月大型底栖生物群落Ⅱ和7月群落Ⅰ受到中等程度的扰动,其它生物群落处于轻微扰动状态。大型底栖生物种类数、密度、种类均匀度和种类丰富度与水深和沉积物特征相关性显著。     

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。     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

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.     

Estimation of Sediment Properties during Benthic Impact Experiments

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.     

A Tidal Flow Model for the Gulf of Kachchh, India

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.     

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

<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     

离子交换—原子吸收光谱法测定海水中痕量铜、铅、锌、镉、铁、锰

本文介绍了用国产D401型螯合树脂分离富集海水中铜、铅、锌、镉、铁、锰等痕量元素,并用原子吸收光谱仪测定其含量的方法。讨论了各元素的分离条件选择及干扰元素的影响,并与溶剂萃取法的结果作了比较。各元素检测的定量下限为:铜0.5μg/L、铅0.1μg/L、锌1.0μg/L、镉0.01μg/L、铁2.0μg/L、锰2.0μg/L。方法精密度在4—8％之间,回收率为90—102％。     

Biogeochemistry of Mangrove Soil Organic Matter: a Comparison BetweenRhizophoraandAvicenniaSoils in South-eastern Brazil

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.     

A review of orange roughy Hoplostethus atlanticus fisheries,estimation methods,biology and stock structure

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.