Evidence of temporal genetic change in wild Atlantic salmon, Salmo salar L., populations affected by farm escapees     

Skaala  Oystein; Wennevik  Vidar; Glover  Kevin A. 《ICES Journal of Marine Science》2006,63(7):1224-1233

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Temporal variation in an immune response gene (MHC I) in anadromous Salmo trutta in an Irish river before and during aquaculture activities     

Coughlan  James; McGinnity  Philip; O'Farrell  Brian; Dillane  Eileen; Diserud  Ola; de Eyto  Elvira; Farrell  Killian; Whelan  Ken; Stet  Rene J.M.; Cross  Thomas F. 《ICES Journal of Marine Science》2006,63(7):1248-1255

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塔里木盆地的构造演化   总被引：6，自引：0，他引：6  

杨克绳 《海洋地质前沿》2005,21(2):25-29

从地震大剖面显示，塔里木盆地发育为手风琴式的演化史。大体上形成有3层“断-坳”结构：①震旦系的“断”，古生界-三叠系的“坳”；②侏罗系的“断”，上白垩系的“坳”；③古近系的“断”，新近系的“坳”。断陷与坳陷分别由拉张与挤压应力场所致，这种应力场的变化是由相邻洋壳板块俯冲倾角由小到大的变化所引起的。由于地壳的多旋回运动，多次发生构造沉积演变，构成了多套生储盖组合，多领域、多种圈闭类型的油气藏，从震旦系-古生界-中生界-新生界，各断陷-坳陷结构的盆地都有可能形成油气藏的地质条件。  相似文献   

Spatial and temporal distribution patterns of deep‐sea mesozooplankton in the eastern Mediterranean – indications of a climatically induced shift?     

Rolf Koppelmann  & Horst Weikert 《Marine Ecology》2007,28(2):259-275

Zooplankton samples from the eastern Mediterranean were collected in April/May 1999 with a multiple opening and closing net (mesh size 333 μm) to examine the distribution and taxonomic composition of mesozooplankton, mainly Calanoida (Copepoda), some years after the onset of the Eastern Mediterranean Transient (EMT), a climatically induced shift in hydrography. The samples from seven stations on a transect from the Ionian Sea to the eastern part of the Levantine Basin were collected at closely spaced vertical intervals from the surface to water depths of 4250 m. Data from January 1987, June 1993, January 1998 and October 2001 from the main site of investigation, south of Crete, were used to describe the temporal evolution before (1987), during (1993) and after (1998–2001) the EMT. The eastern Mediterranean mesozooplankton fauna is dominated by three Calanoida species along the west–east transect, with varying abundances in different depth‐zones: Haloptilus longicornis in the epipelagic zone, Eucalanus monachus in the mesopelagic zone, and Lucicutia longiserrata in the bathypelagic zone. A drastic change in mesozooplankton composition and abundance occurred at the main site during the EMT, whereupon increased abundances of Candacia elongata and L. longiserrata were observed in the bathypelagic zone in the following years; L. longiserrata accounted for 43% of the total mesozooplankton in this zone. The hypothesis is posed that the Mediterranean deep‐sea ecosystem is able to respond quickly to changes in the environment and memorizes these changes over time. We claim that the biological effects of climatically induced changes can be easily monitored in the deep eastern Mediterranean Sea using calanoid copepod key species due to the hydrographically extreme, but ‘simply structured’ ecosystem.  相似文献   

成山卫沙坝潟湖链的形成和近期演化     

王永红  庄振业  李从先  李学伦 《海洋学报》2001,23(2):86-92

山东荣成市成山头南侧发育了一条沙坝和一系列的湖 ,组成成山卫湖链 ,以面积最大的天鹅湖有关资料为主 ,运用粒度分析、软体动物鉴定、14 C测年等方法 ,对So5 ,Sh5 ,Sh1和Sh6孔岩心进行分析 ,揭示了该湖链的形成过程 :距今 70 0 0a左右 ,海水开始入侵 ,形成了荣成湾 ,距今 6 0 0 0a左右 ,沙坝和坝内的一系列半封闭湖形成 .根据沙坝层理的观测资料分析了湖形成后自然作用下的演化动态 ,并指出近年来由于人类活动加剧 ,严重影响了湖的演化过程  相似文献   

Short-term shoreline changes due to cross-shore structures: a one-line numerical model     

I. O. Leont'yev   《Coastal Engineering》1997,31(1-4)

The proposed numerical model simulates the short-term temporal changes in shoreline position due to a structure interrupting the longshore sediment flux. The impacts of both the groin-type construction and underwater trench of arbitrary orientation relative to the shore are discussed. In order to estimate the sediment mass trapped by the structure, a submodel of the longshore sediment transport induced by a random wave field is developed. The contribution of the surface roller in momentum balance as well as in sediment suspension is included. The shoreline changes are computed from the equation deduced from the mass conservation. The perturbations in the longshore sediment discharge caused by a structure are assumed to concentrate within some boundary area of which the spatial scale is proportional to the structure's length until the latter is exceeded by the width of the sediment flux. It is shown in particular that the total effect of a long trench (channel) and a pier in its nearshore part results in general shoreline recession except for the vicinity of a pier. The model is tested against the laboratory data of Baidei et al. (1994) and applied to the Baidara Bay coast (Kara Sea) where a pipeline would be designed.  相似文献   

黄河尾闾河道1996年改道的意义及黄河三角洲演化趋势   总被引：3，自引：0，他引：3  

尹延鸿  亓发庆 《海岸工程》2001,20(4):36-42

现代黄河三角洲由几个亚三角洲组成。 1 85 5 -1 93 4年 ,形成了以宁海为顶点的第一亚三角洲 ;1 93 4-1 996年 ,三角洲冲积扇顶点进一步下移 ,形成了以渔洼为顶点的第二亚三角洲。最近的一次改道是在 1 996年 6月 ,改道后的河流沿清水沟流路的清 8剖面附近东流入海。这次改道可能是第三亚三角洲形成的开始。以后数十年内的黄河尾闾摆动将在清 8剖面附近进行。虽然人类活动将对三角洲的发展演化产生越来越明显的影响 ,但这些亚三角洲的发育演化仍有明显的规律性  相似文献   

赤潮叉角藻18SrDNA和ITS区序列测定与分析   总被引：20，自引：0，他引：20  

庄丽  陈月琴  李钦亮  屈良鹄 《海洋与湖沼》2001,32(2):148-154

采用PCR及克隆测序的方法，对1998年引发渤海赤潮的叉角藻18SrRNAadldey DNAITS区（Internal Transcribed Spacer Regions)进行了序列测定与分析。并通过因特网从国际分子生物学数据库中获取甲藻另外15个种的18rDNA序列，以Tetrahymena corlissi作为类群，分别采用Neighbor-Joining和Fitch方法构建甲藻较为一致和可靠的进化树图，探讨具有高度多样性和在分类上争议较多的甲藻各类群之间的形态与分子进化关系。结果表明，Prorocentrum(有2个简单的壳板）出现得较早，而大多数多甲藻目（覆盖着多个壳板）、裸甲藻目（大多数不具壳板）和膝沟藻目的成员较晚出现。另外，对叉角藻ITS区的分析表明，ITS区为高变区，是良好的分子标记，可用于叉角藻快速鉴定的专一性核酸分子探针的研制。  相似文献   

Nereis diversicolor: an Unreliable Biomonitor of Metal Contamination in the 'Ría de Bilbao' (Spain)     

J. I. Saiz-Salinas  G. Francés-Zubillaga   《Marine Ecology》1997,18(2):113-125

Abstract. Samples of the polychaete Nereis diversicolor O.F. M üller and surficial sediments from a clean and a polluted estuary were taken during a year at monthly intervals to determine, by comparison, the range of temporal fluctuations in trace metal concentrations. Whereas metal variations in surficial sediments were more pronounced in the polluted estuary, concentrations in N. diversicolor in both estuaries showed a wide range of temporal variation that surpassed that of surficial sediments. A clear decline in all metals studied (except Mn) from polluted sediments was noted after episodes of strong rainfall. In the reference estuary the fluctuations were less pronounced. Metal body burdens in N. diversicolor from the two estuaries were usually quite similar even though total levels in sediments differed considerably, indicating a lack of worm-sediment relationship. The low level of Cu, Cr and Pb in the tissues of N. diversicolor suggest a mechanism which prevents the polychaete from being exposed to these metals in highly polluted sediments. Therefore, it is concluded that N. diversicolor cannot be considered to be an ideal biomonitor of metal contamination in the polluted Bilbao Estuary.  相似文献   

南海西南部新生代盆地类型及演化历史   总被引：4，自引：0，他引：4  

钟广见  王Liao亮 《海洋湖沼通报》1996,(2):24-32

南海西南部地区发育了多种类型的新生代沉积盆地，各种类型的盆地具有各自的结构特征和演化历史，走滑－周缘前陆盆地－曾母盆地发育了渐新－中中新统层系，晚中新统层系和上新－第四系层系第三套地层，曾母盆地经历了三个发育阶段，拉张剪切盆地－万安盆地发育下第三系－下渐新统层系，上渐新统一中中新统层系和上中新统一第四系层系三套地层，万安盆地经历了四个发育阶段。  相似文献