广西珍珠湾红树种群结构与动态特征

本研究以种群生命表为基础,对位于广西珍珠湾内的桐花树(Aegiceras corniculatum)种群、白骨壤(Avicennia marina)种群、秋茄(Kandelia obovata)种群和木榄(Bruguiera gymnorrhiza)种群采用径级法及匀滑技术,编制种群特定时间生命表,绘制种群存活曲线、死亡率和消失率曲线,进行种群数量动态变化和时间序列分析。结果表明:(1)白骨壤种群、秋茄种群和木榄种群年龄结构呈倒"J"形,种群趋于Deevey-II型,即增长型,主要集中在I龄级,存活曲线、死亡率和消失率曲线均呈现出更新层死亡率较高的特征;(2)桐花树种群年龄结构呈"金字塔"形,属于Deevey-I型,为衰退型,更新层个体数量少,种群总体不具备显著增长性幅度;(3)4种红树种群的数量变化动态指数V_pi和V′_pi均大于0.00%,种群稳定但易受外部环境影响;(4)在未来2、4、6、8个龄级时间后,4种红树种群中老龄级个体能够得到不同程度的补充。     

三亚海洋“热带雨林”保护现状

<正>三亚珊瑚礁国家级自然保护区位于海南省三亚市南部附近海域,地理位置在东经109°20′50″~109°40′30″和北纬18°10′30″~18°15′30″范围内,保护区总面积85平方千米;实际保护海域、岛礁面积为70.02平方千米;由亚龙湾片区、鹿回头半岛——榆林角沿岸片区和东、西瑁洲片区三个区域组成。各片区分有核心区、缓冲区和实验区。保护区内有东瑁洲、西瑁洲、小青洲、野猪岛、东排礁和西排礁等岛礁。保护区的主要保护对象是造礁石珊瑚、非造礁珊瑚、珊瑚礁及其生态系统和生物多样性。     

南沙群岛西南部海域鱼类群落结构分析

南沙群岛是南海中最靠南、岛礁最多、散布最广的岛;南沙群岛海区南起3°57′N,北至11°55′N,西起103°30′E,东至117°50′E,由众多礁、滩、岛屿等组成,为典型的热带海域。为进一步研究该海域,国家海洋局第三海洋研究所在2012—2013年在南沙群岛西南部海域共开展了春秋2个航次的调查;根据该调查资料分析了该海域的鱼类群落结构。调查共获得鱼类357种,隶属于27目108科219属,其中暖水性鱼类327种,暖温性鱼类30种。优势种鱼类(IRI500)有菲律宾尖牙鲈(Synagrops philippinensis)、土佐副眶棘鲈(Parascolopsis tosensis)、锯棘尖牙鲈(Synagrops serratospinosus)等5种,多为中小型鱼类,且季节间变化较大。分析多样性指数显示,南沙群岛西南部海域的Margalef种类丰富度指数(D)变化范围较大(3.05~4.20),两季间变化最为明显;Shannon-Wiener多样性指数(H’)春秋两季间变动范围较小(2.31~2.69);Pielou均匀度指数(J’)季节间基本保持一致(0.69~0.70);更替指数和迁移指数显示,秋季鱼类群落结构稳定性要低于春季,而且两个季节的鱼类群落结构都偏离平衡状态;同时分析数量生物量曲线显示,春秋两季的数量优势度曲线均在生物量优势度曲线之上,表明群落主要以生长较快,个体较小的r选择物种为主,群落受到的干扰程度较高,稳定性较差。鱼类的洄游、不同适温性鱼类的迁入迁出以及繁殖群体的补充、个体生长、捕捞等都是影响群落稳定性的因素。     

红树植物木榄种群植冠层结构的分形特征

应用分形理论分析了山口国家级红树林保护区木榄种群植冠层结构的分形特征。木缆3a生枝条的计盒维数介于1.22-1.55之间，这些维数值揭示了分枝结构的复杂程度以及占据生态空间和利用生态空间的能力。分形维数为了解木缆的光能利用效率和掌握它的生长发育过程提供了一个有用的指标。根据双表面积法，20－50a的木缆树冠格局的分形维数介于2.21-2.54之间，表明叶片对树冠的填充程度较低，该树种具有阳生的性质。随着种群个体年龄的增长，树冠被叶片填充的程度出现了由高到低的变化，其分形维数相应地呈现由高到低的动态变化特征。根据植冠层的灰度图分析，得出种群植冠层的计盒维数介于1.47-1.61之间。计盒维数越大，表明种群植冠层的空间结构越松散，透光的空斑块越多，计盒维数有效地揭示了种群植冠层包含于图像中的结构信息及其复杂性。     

基于支持向量机的库克群岛海域长鳍金枪鱼栖息环境综合指数

掌握海洋环境因子对长鳍金枪鱼(Thunnus alalunga)资源密度分布的影响有利于该资源的可持续利用。根据2013年9-12月在库克群岛海域利用延绳钓调查所获得的共计56个站点的长鳍金枪鱼渔获率数据,以及测得的温度、叶绿素a浓度、水平海流及垂直海流等环境因子数据,采用支持向量机方法分析了各水层(40.0~239.9 m,每40 m为一层)及整个水体中各个环境因子与长鳍金枪鱼渔获率的关系并建立了长鳍金枪鱼栖息环境综合指数(IHI)模型,并利用验证站点对模型进行了验证。结果表明:(1)预测渔获率与其对应的名义渔获率无显著性差异;(2)IHI模型的预测能力较好,能有效预测长鳍金枪鱼的分布;(3)不同水层影响长鳍金枪鱼分布的主要因素不同,在40.0~79.9 m、80.0~119.9 m、120.0~159.9 m、160.0~199.9 m和200.0~239.9m水层其分布分别主要受叶绿素a浓度、水温、垂直海流、叶绿素a浓度和温度的影响。整个水体影响长鳍金枪鱼分布的主要因素为温度;(4)长鳍金枪鱼分布密度较高的水层为120.0~199.9 m;(5)长鳍金枪鱼IHI指数分布较高的3个区域分别为9°00′S-12°20′S,159°00′W-164°00′W、13°30′S-14°30′S,159°00′W-161°00′W和10°30′S-12°30′S,167°00′W-168°00′W,建议在上述海域作业时,应使钓具沉降到120~199.9 m水层,以减少其它物种的兼捕率并提高长鳍金枪鱼的渔获率。     

中国黄海封闭与开放水域大叶藻种群动态研究

为探明黄海海域不同生境下大叶藻(Zostera marina L.)种群特征,自2011年2月至2012年6月,对黄海山东半岛两处不同大叶藻生境[烟台四十里湾海区(开放水域生境SSL:37°02.531′N,122°32.693′E)和荣成爱莲湾海区围堰池(半封闭水域生境AL:37°14.925′N,122°35.716′E)]种群季节动态规律和繁殖状况进行了跟踪观测。结果显示:处于半封闭水域生境的爱莲湾大叶藻种群平均峰值植株高度、地上/地下干重生物量、种群植株密度、繁殖枝密度(107.42cm,754.84g/113.21g·m-2,364株·m-2,109.21株·m-2)显著大于开放水域生境四十里湾大叶藻种群(66.98cm,487.63g/127.63g·m-2,273.21株·m-2,69.21株·m-2)(P0.05)。两生境下大叶藻种子大小存在显著差异,开放水域生境四十里湾大叶藻种群种子大小(平均长4.17mm,宽2.02mm,重11.13mg)显著大于半封闭水域生境爱莲湾种子(平均长3.43mm,宽1.75mm,重6.97mg)(P0.05)。处于半封闭水域生境的种群具有更高生物量和种群密度,产生更多繁殖枝,但是种子远小于开放水域生境大叶藻种群产生的种子,表明浪冲击生境下大叶藻种群具有更强的有性繁殖拓殖能力。     

印度洋西北部公海鸢乌贼资源特征及其与海况的关系

根据2004年9月~2005年4月我国鱿钓船在印度洋西北部12°N~21°30′N,58°E~65°E获得的鸢乌贼资源调查资料,对其资源特征及其与海况关系进行了分析。研究认为,调查海域内鸢乌贼均有一定的分布,其中以14°30′N、60°E~63°E附近海域CPUE为最高。渔获物胴长范围为163~560 mm,优势胴长组为280~440 mm,占总数的70.51%,平均胴长为365.0 mm。渔获个体组成随纬度变化差异显著,而随经度变化差异不明显。16°N以南海域,雌性个体一般以Ⅰ、Ⅱ期为主;16°N以北海域,则以Ⅲ~Ⅴ期为主。分析还认为,鸢乌贼分布与表温、海面高度距平关系密切,9~11月适宜表温为27~28℃,12月~翌年3月为26~27℃,高产渔场大都分布在海面高度距平SSHA≤0的附近海域。     

北大西洋大青鲨渔业生物学初步研究

大青鲨(Prionace glauca)是金枪鱼延绳钓渔业中最主要的兼捕鱼种之一,作为海洋生物链的顶端物种对海洋生态系统的稳定性和多样性起到了重要作用。作者根据中国金枪鱼渔业科学观察员在北大西洋海域(3°~55°N,15°~40°W)采集的2 112尾大青鲨数据,按不同性别对其渔业生物学特征进行初步研究。结果表明:雌、雄大青鲨的优势叉长组分别为180~220 cm、190~230 cm,雄性叉长均值显著大于雌性,雌、雄性比符合1︰1;大青鲨叉长-全长、尾凹长-全长的线性关系分别为L_F=0.8008L_T+7.3361,L_P=0.7576L_T–1.8479;北大西洋热带海域(3°~13°N)兼捕的大青鲨群体组成以大个体为主(180~240 cm),冰岛附近海域(48°~51°N)兼捕的大青鲨群体组成以小个体为主(100~210 cm);大青鲨叉长和质量关系式为W_R=7×10~(–6)L_F~(2.9994);大青鲨肝脏为性腺的发育提供能量,成熟个体的肝质量指数显著小于未成熟个体;热带海域兼捕的大青鲨以性成熟个体为主(96.9%),冰岛海域兼捕的大青鲨以未成熟个体居多(77.1%);50%雌性性成熟个体对应的叉长为178.7 cm,50%雄性性成熟个体对应叉长为173.6 cm;雌性怀仔大青鲨的叉长与其怀仔数量线性关系为L_S=0.419×L_F–49.7(R~2=0.3905),幼仔雌雄性比符合1︰1;胃含物中以沙丁鱼和鱿鱼出现频率最高。作者的研究有助于更好地了解北大西洋大青鲨的生物学特征,为区域性渔业管理组织评估大青鲨种群资源状态提供数据参考。     

基于形态法的西北太平洋柔鱼种群结构研究

西北太平洋柔鱼是我国鱿钓渔业重要捕捞对象,种群结构是渔业生物学研究的基础内容.文中根据2007年7~10月40°N~45°N,151°E~158°E海域连续采集的1 342尾柔鱼样本,测定其胴长(ML)、腕长等12项形态指标,利用正态线性转化、主成分分析和判别分析等方法研究雌雄个体的种群结构.结果表明,该海域雌、雄柔鱼均存在大小2个种群.均数差异显著性表明,雌性个体2个种群在MW/ML和FW/ML存在显著差异,雄性个体在MW/ML和AL_3/ML存在显著差异,但其形态差异仍属于种内差异.主成分分析和逐步判别分析的判别准确率(雌性60.3%,雄性60.1%),说明所划分的种群在部分形态比指标上差异明显.研究认为,形态学指标可初步区分西北太平洋柔鱼种群,但需结合其他生态学指标和耳石等硬组织进一步划分.     

印度洋西北部海域鸢乌贼渔场分布及其与海面温度的关系

根据2004年9月-2005年4月印度洋西北海域鸢乌贼生产调查资料及海面温度数据,按经纬度1°×1°空间分辨率,采用软件Marine Explorer 4.0和数理统计方法对鸢乌贼作业渔场分布及其与海面温度的关系进行了分析。结果显示,9月-翌年1月作业渔场分布比较分散,分布在11°30′~19°30′N,58°~64°E海域;2-4月作业渔场分布比较集中,主要分布在15°~16°30′N,60°~61°30′E。各月份的平均日产量波动不大。作业渔场的适宜海面温度为25~29℃。经Kruskal-Wallis统计检验,调查期间各个温度组作业CPUE不存在显著性差异。     

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.     

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.     

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.     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

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.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

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.