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1.
根据2006年6~11月我国远洋船队秘鲁茎柔鱼生产统计及其表温(SST)、表温距平值(SSTA)数据,利用GIS软件ArcGIS9.0,对各月平均日产量(CPUE)和SST、SSTA关系的分布图进行绘制并分析,计算作业渔场重心。结果表明,6~8月的产量和CPUE比其他月份高。6~11月作业渔场在80°W~85°W,10°S~15°S,渔场重心在81°W~84°W,11°S~14°S。产量主要集中在12°~14°S海域,约占年总产量的72.72%,与2004-2005年有较大差异。6月作业渔场的SST为21~23℃,7、8月分别为19~21℃和18~20℃,9~11月为18~21℃。6月作业渔场的SSTA为0.1~0.2℃,7、8月分别为0.5~0.7℃,9~11月分别为0.2~0.6℃、1.0~1.4℃和0.4~0.7℃。研究认为,茎柔鱼渔场分布与SST、SSTA关系密切,可作为寻找中心渔场的海洋环境指标。  相似文献   

2.
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。  相似文献   

3.
为了解太平洋大眼金枪鱼(Thunnus obesus)和黄鳍金枪鱼(Thunnus albacares)主要作业渔场次表层关键环境变量时空分布特征,作者采用2007~2012年Argo剖面浮标数据,分析了太平洋大眼金枪鱼和黄鳍金枪鱼延绳钓主要作业渔场区温跃层特征参数、12℃和距表层海温8℃(Δ8℃)等值线信息。研究表明,温跃层上界深度和温度以及Δ8℃等深线具有明显的季节性变化。温跃层上界深度呈现出冬深、夏浅的季节性变化特征,大致呈纬向带状分布。1~3月份,北太平洋从东到西温跃层上界深度值都超过90 m,同期10°S以南的海域均低于60 m;7~9月份则相反。在太平洋150°W以西,20°S~20°N区域,温跃层上界温度全年在28℃以上。8℃等深线显示在东部太平洋,一块低值区域(150m)由东海岸向西海岸延伸;在20°N以北和20°S以南的高值区域(250m)表现出冬深、夏浅的季节性变化特征。温跃层下界深度图显示有两块高值区域(深度大于280m)从西向东,由低纬度向高纬度漂移;在东部太平洋,两个高值区域之间的纬向区域常年存在一块下界深度低值区域(140m)。与下界深度类似,温跃层下界温度也有两块低温区域(12℃)从西向东,由低纬度向高纬度漂移。在该低温区域的外侧舌状区域,下界温度超过17℃;东部太平洋在13~15℃。在15°N以北和15°S以南12℃等深线超过400 m,呈舌状;赤道东部太平洋,一块300 m深的细长舌状区域由东向西延伸。在上述区域之间,12℃等深线的深度值低于200 m。温跃层下界深度和温度,以及12℃等深线则没有明显的季节性变化。分析结果初步揭示了太平洋金枪鱼主要作业渔场温跃层上界温度、12℃和Δ8℃等值线信息分布特征,为金枪鱼实际生产作业提供理论参考。  相似文献   

4.
秘鲁外海茎柔鱼渔场时空分布分析   总被引:3,自引:0,他引:3  
秘鲁外海茎柔鱼是重要的经济性种类,掌握其渔场时空分布规律有助于资源的合理利用。本文根据2003—2004年和2006—2009年我国鱿钓船在秘鲁外海的生产统计和海洋表面温度(SST)等资料,使用空间距离和聚类分析的方法,对其各年间渔场时空分布进行分析比较。结果表明,各年产量重心的分布都存在一定差异,产量重心在经度上随月份整体上呈现向西移动的趋势,在纬度方向上1~6月整体上呈向北移动的趋势,7~12月则表现出向南移动的趋势。聚类分析表明,2003、2006和2008年;2004、2007和2009年空间分布格局各为一类。空间距离分析表明,2006和2009年产量重心差异最大,其中前者平均产量重心为82°23′W、12°53′S,后者为81°47′W、14°27′S,南北相差约1.5个纬度。研究认为,渔场分布的月间变化是由茎柔鱼南北洄游所引起的,年间渔场分布差异与SST等海洋环境关系密切。  相似文献   

5.
西北太平洋公海区域为我国近年来重点开发的海域,而日本鲭(Scomber japonicus)为该海域的重要经济鱼种,本文初步探讨了该海域日本鲭渔场的形成机制。根据2015年4—6月春季航次和2016年6—7月夏季航次西北太平洋灯光围网船各站点的调查数据,对日本鲭资源丰度分布与海表面温度(Sea Surface Temperture,SST)、水温垂直结构的关系进行了分析。研究显示:春季日本鲭的站位平均渔获率为736.94 kg/h,高于夏季的498.87 kg/h。日本鲭渔场的分布范围随季节变化而略有差异,春季主要集中在40°N、151°E~153°E海域,夏季主要集中在41°N、154°E~160°E海域。春、夏两季渔场的SST范围有所差异,春季渔场SST范围为7~19℃,最适SST为11~15℃;夏季渔场SST范围为8~24℃,最适SST为8~12℃。分析了不同季节的5~50、50~100和5~100 m水温垂直梯度与站位平均渔获率的关系,表明不同季节渔场的水温垂直梯度差异明显,从50~100 m水温垂直梯度来看,春季日本鲭的站位平均渔获率在0.10~0.15℃/m组距内达最大;夏季,站位平均渔获率随水温垂直梯度增加而减少,在-0.05~0.00℃/m组距内达最大。灰色关联度分析表明,ΔT_(50~100)(50~100 m水温垂直梯度)是对日本鲭渔获率影响最显著的因子,关联度为0.991,纬度、经度和T_(50)等次之。同时分析了所选取的3个代表性站点的水温垂直结构,表明在50~100 m水深范围内有温跃层的站点渔获产量较高,因此,日本鲭渔获率的大小可能与50~100 m水深范围内温跃层的形成密切相关。  相似文献   

6.
根据2004年9~12月在阿拉伯北部公海海域鸢乌贼资源的探捕生产情况,分海区初步分析了海洋环境因子与中心渔场之间的关系。调查表明,中心渔场分布在62°E~64°E、12°N~13°N,59°E~62°E、15°N~18°N和62°E~64°E、18°N~20°N三个海区。中心作业渔场基本分布在冷水与暖水交汇边缘处,并处于冷水涡边缘一侧。中心渔场的适宜表温27~29℃、表层盐度35.5~36.5。不同作业渔场的温盐结构不同。北部渔场的表温相对要高于南部渔场,但是50m以下水层的温度则相反;中部渔场的各层盐度明显低于南部和北部渔场。GAM模型分析表明,产量与表温、50m水温和200m水温以及各层盐度的关系密切。  相似文献   

7.
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   总被引:3,自引:0,他引:3  
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。  相似文献   

8.
太平洋延绳钓长鳍金枪鱼及渔场水温分析   总被引:4,自引:0,他引:4  
根据收集到的渔获量数据、海水表层温度数据及有关文献资料,应用GIS技术对太平洋长鳍金枪鱼延绳钓渔业进行定量和定性综合分析。结果表明:太平洋延绳钓长鳍金枪鱼渔场分布范围广泛,具纬向分布特征,集中分布在30°N线附近的西北太平洋海域和~40°S之间的西南太平洋海域。对渔获产量同海表温度的分月统计显示:太平洋长鳍金枪鱼渔场最适月平均表层水温约28~29℃,渔场出现频次为偏态分布型。文中结合有关文献综合讨论了海表温度、溶解氧含量、海流等环境因子与金枪鱼渔场分布和形成机制的关系。  相似文献   

9.
中西太平洋延绳钓黄鳍金枪鱼渔场时空分布与温跃层关系   总被引:3,自引:2,他引:1  
为了解热带中西太平洋延绳钓黄鳍金枪鱼(Thunnus albacares)适宜的温跃层参数分布区间,采用Argo浮标温度信息和中西太平洋渔业委员会(The Western and Central Pacific Fisheries Commission,WCPFC)的黄鳍金枪鱼延绳钓渔获数据,绘制了热带中西太平洋月平均温跃层特征参数和月平均CPUE的空间叠加图,用于分析热带中西太平洋黄鳍金枪鱼中心渔场时空分布和温跃层特征参数间的关系。分析结果表明:热带中西太平洋温跃层上界深度、温度具有明显的季节性变化,而温跃层下界深度、温度季节性变化不明显,黄鳍金枪鱼中心渔场分布和温跃层季节性变化有关。全年中心渔场的位置分布在温跃层上界深度高值区域,随温跃层上界深度高值区域季节性南北移动。在新几内亚以东纬向区域(5°N~10°S,150°E~170°W)上界深度值全年都在70~100m之间,全年都是延绳钓黄鳍金枪鱼中心渔场。中心渔场上界温度多在26℃以上,但是在上界温度超过30℃区域,CPUE值较小。中心渔场主要分布在温跃层下界深度两条高值带之间区域,在温跃层下界深度超过300m和小于150m区域,CPUE值均偏低。中心渔场主要分布在下界温度低于13℃区域,下界温度超过17℃难以形成中心渔场。频次分析和经验累积分布函数计算其适宜温跃层特征参数分布,得出中西太平洋黄鳍金枪鱼适宜的温跃层上界温度和深度分别是27~29.9℃和70~109m;适宜的温跃层下界温度和深度分别是11~13.9℃和250~299m。文章初步得出中西太平洋黄鳍金枪鱼中心渔场温跃层各特征参数的适宜分布区间及季节变化特征,为我国金枪鱼实际生产作业提供技术支持。  相似文献   

10.
毛里塔尼亚底拖网作业渔场时空分布研究   总被引:1,自引:0,他引:1  
毛里塔尼亚位是我国在西非的主要入渔国家之一。把握底拖网作业渔场时空分布及其规律是渔业生产的重要内容。本研究根据2010—2015年上海某渔业公司在毛里塔尼亚海域的底拖网渔船生产统计数据,采用频度分析法和渔场重心法对底拖网作业渔场时空分布进行研究。研究认为,毛里塔尼亚底拖网作业渔场分布在16.90°W~17.70°W、19.70°N~20.80°N海域,主要集中在17.40°W~17.60°W、20.20°N~20.70°N海域。平均网次产量为27~77kg,总体平均网次产量为43.98kg。研究认为,渔场重心呈现出规律的分布,基本上分布在1个经纬度范围内。1~4月份渔场重心主要分布在17.38°W~17.59°W、20.49°N~20.56°N海域;7~8月主要分布在17.21°W~17.33°W、20.26°N~20.48°N海域;9~11月主要分布在17.43°W~17.54°W、20.40°N~20.64°N海域;12月主要分布在17.08°W、20.00°N附近海域。作业渔场时空分布规律的掌握,有助于毛里塔尼亚海洋渔业的合理生产。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

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《海洋学报(英文版)》2014,(11):161-F0003
<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,  相似文献   

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