海水硬骨鱼白点病组织病理学研究   总被引：2，自引：0，他引：2  

徐润林  陈毕生  江静波 《海洋科学》1992,16(5):16-21

在光镜水平下研究了刺激隐核虫寄生黄鳍鲷和真鲷后引起宿主组织病理学的变化。该寄生虫可在宿主皮肤、鳃上皮和舌上皮的组织内寄生。与正常组织相比,被寄生的皮肤表皮层明显增厚、粗糙,其增厚部分主要是粘液细胞层、表皮层与真皮层间的联系被破坏。寄生囊内有较大的空隙。虫体内含有大量的宿主细胞残骸。由于寄生虫的感染,使得非寄生部位的脏器也出现某些病理变化:肝细胞萎缩,窦状隙增大;脾肾内都有颗粒性沉积。本研究结果还与淡水“白点”病引起的病理组织学变化进行了比较。  相似文献   

珠江口现代沉积速率及其反映的沉积特征   总被引：2，自引：0，他引：2  

陈耀泰  罗章仁 《热带海洋学报》1991,(2)

文章分析了珠江河口海区泥沙来源及淤积动态,采用以历史海图分析对比为主,~(210)Pb测年数据校核等方法,参考有关沉积速率定性方面的标志,推算出珠江口不同地段的现代沉积速率,并相应划分出高速率沉积、快速率沉积、中速率沉积和慢速率沉积或稍有侵蚀等4个分区.进而,还论述了沉积作用的特征.  相似文献   

A three-layer model for the thermal structure in the Huanghai Sea     

Wan Bangjun  Guo Binghuo  Chen Zeshi 《海洋学报(英文版)》1990,9(2):159-172

A one-dimentional three-layer model for the thermal structure in the Huanghai Sea is presented in this study, me model consists of the upper mixed layer caused by heating and wind mixing, the lower mixed layer driven by tidal mixing, and the thermocline with certain thickness. The entrainment velocities of the upper and lower layers are obtained respectively. The results show that the model is capable of describing the development and decline processes of the seasonal thermocline in the Huanghai Sea, simulating successfully the Huanghai Sea Cold Water Mass, the nearshore front and surface cold water off North Jiangsu and explaining reasonably their formation mechanisms as well as the strong thermocline off Qingdao. It is suggested that the tidal mixing plays key role in the formation of the nearshore front off North Jiangsu and the strong thermocline off Qingdao. The wind mixing and the tidal mixing make the lower layer water with high nutrients go up to the upper layer. This physical process may be sig  相似文献   

The behaviour of ⁵⁹Fe in marine microhabitat     

Cai Fulong  Chen Ying  Xu Pi''an  Oiu Manhua 《海洋学报(英文版)》1989,8(3):423-429

Under the artificial condition the 59Fe morphology in sea water, its concentration in sediment and phytoplankton, its distribution and metabolism in tissue organs of marine animals were studied. The results showed that the morphology of 59Fe was in a particulate state in sea water. The adsorption rule of 59Fe by three kinds of sediments was similar. The concentration ability of 59Fe by phytoplankton was very strong. The critical concentration organs of S9Fe by marine animals were viscera. The gross radioactivity of 59Fe was mainly concentrated in protein. The concentration factor of 59Fe by DNA was the highest one. After excretion experiment, 59Fe of all the tissue organs was not detected. Small part of59Fe remained in the organic acid and protein state. There was a redistribution process in sediment for59Fe.  相似文献   

Theoretical wind wave frequency spectra in shallow water     

Wen Shengchang 《海洋学报(英文版)》1988,7(3):325-343

The method developed by Wen et al. (1988 a) for deriving theoretical wind wave frequency spectrum in deep water is extended to the case of water of finite depth, in which a parameter η=H/d is introduced, where H and d represent the average wave height and water depth respectively. The derived spectra reduce to those in deep water when η=0. The case of η=1/2 corresponds to waves impending to break because of the effect of the bottom. Simplified forms of spectra are given. The theoretical results agree with the observed spectra well.  相似文献   

我国海洋软相底质底栖经济贝类的可持续利用探讨   总被引：1，自引：0，他引：1  

吴进锋  梁超愉  陈利雄  陈素文  李夏 《海洋湖沼通报》2005,(2):93-98

分析了海洋软相底质底栖贝类的资源特性和我国的资源利用现状及存在问题．并从规模化苗种生产、海区增殖、高效养殖模式开发及增养殖环境保障与产品无公害生产等方面对该资源的可持续利用进行了探讨。  相似文献   

Seismic structure and tectonics of the Shackleton Fracture Zone (Drake Passage,Scotia Sea)     

Riccardo?Geletti  Emanuele?LodoloEmail author  Anatoly?A.?Schreider  Alina?Polonia 《Marine Geophysical Researches》2005,26(1):17-28

The structural framework of the southern part of the Shackleton Fracture Zone has been investigated through the analysis of a 130-km-long multichannel seismic reflection profile acquired orthogonally to the fracture zone near 60° S. The Shackleton Fracture Zone is a 800-km-long, mostly rectilinear and pronounced bathymetric lineation joining the westernmost South Scotia Ridge to southern South America south of Cape Horn, separating the western Scotia Sea plate from the Antarctic plate. Conventional processing applied to the seismic data outlines the main structures of the Shackleton Fracture Zone, but only the use of enhanced techniques, such as accurate velocity analyses and pre-stack depth migration, provides a good definition of the acoustic basement and the architecture of the sedimentary sequences. In particular, a strong and mostly continuous reflector found at about 8.0 s two-way traveltime is very clear across the entire section and is interpreted as the Moho discontinuity. Data show a complex system of troughs developed along the eastern flank of the crustal ridge, containing tilted and rotated blocks, and the presence of a prominent listric normal fault developed within the oceanic crust. Positive flower structures developed within the oceanic basement indicate strike-slip tectonism and partial reactivation of pre-existing faults. Present-day tectonic activity is found mostly in correspondence to the relief, whereas fault-induced deformation is negligible across the entire trough system. This indicates that the E–W-directed stress regime present in the Drake Passage region is mainly dissipated along a narrow zone within the Shackleton Ridge axis. A reappraisal of all available magnetic anomaly identifications in the western Scotia Sea and in the former Phoenix plate, in conjunction with new magnetic profiles acquired to the east of the Shackleton Fracture Zone off the Tierra del Fuego continental margin, has allowed us to propose a simple reconstruction of Shackleton Fracture Zone development in the general context of the Drake Passage opening.  相似文献   

Simulations of Annual Cycle of Phytoplankton Production and the Utilization of Nitrogen in the Yellow Sea     

Tian?TianEmail author  Hao?Wei  Jian?Su  Changsoo?Chung 《Journal of Oceanography》2005,61(2):343-357

A nutrient dynamic model coupled with a 3D physical model has been developed to study the annual cycle of phytoplankton production in the Yellow Sea. The biological model involves interactions between inorganic nitrogen (nitrate and ammonium), phosphate and phytoplankton biomass. The model successfully reproduces the main features of phytoplankton-nutrient variation and dynamics of production. 1. The well-mixed coastal water is characterized by high primary production, as well as high new production. 2. In summer, the convergence of tidal front is an important hydrodynamic process, which contributes to high biomass at frontal areas. 3. The evolution of phytoplankton blooms and thermocline in the central region demonstrate that mixing is a dominant factor to the production in the Yellow Sea. In this simulation, nitrate- and ammonium-based productions are estimated regionally and temporally. The northern Yellow Sea is one of the highly ranked regions in the Yellow Sea for the capability of fixing carbon and nitrogen. The annual averaged f-ratio of 0.37 indicates that regenerated production prevails over the Yellow Sea. The result also shows that phosphate is the major nutrient, limiting phytoplankton growth throughout the year and it can be an indicator to predict the bloom magnitude. Finally, the relative roles of external nutrient sources have been evaluated, and benthic fluxes might play a significant role in compensating 54.6% of new nitrogen for new production consumption.  相似文献   

Total Lipid and Fatty Acid Classes in Decomposing Mangrove Leaves of <Emphasis Type="Italic">Bruguiera gymnorrhiza</Emphasis> and <Emphasis Type="Italic">Kandelia candel</Emphasis>: Significance with respect to Lipid Input     

Prosper?L.?Mfilinge  Tarik?Meziane  Zainudin?Bachok  Makoto?TsuchiyaEmail author 《Journal of Oceanography》2005,61(3):613-622

Changes in the concentration of total lipid and fatty acids (FAs) during the decomposition of mangrove leaves were investigated by field experiments using yellow leaves of Bruguiera gymnorrhiza (L.) Lamk. and Kandelia candel (L.) Druce, in order to quantify mangrove contribution to lipid and fatty acid inputs to marine sediments. Total lipid and total FA in the fresh (green and yellow) and decomposing leaves of both species were significantly higher during winter than summer. During decomposition, total lipid content and FA concentration, in particular branched chain fatty acids (BrFAs) and bacterial fatty acids (BFAs), increased to a maximum concentration in 45 days during winter and in 17 days during summer. Lipids were lost faster in K. candel leaf detritus than in B. gymnorrhiza leaf detritus in which >90% of the total lipid original weight was lost during the summer experiment and <60% during the winter experiment. The changes in the concentrations of total lipids and FAs in the decomposing leaves also indicate that mangrove leaves are significant sources of fatty acids and probably other lipid compounds to estuarine ecosystems and that tidal waters transport the lipids and FAs adsorbed to particulate matter from mangroves to adjacent estuarine sediments and the ocean.  相似文献   

Occurrence and environmental implications of magnetic iron sulfides in stiff muds from the continental shelf of the East China Sea     

Zhanghua Wang  Zhongyuan Chen  Jiawei Gu  Yanhong Li  Weixian Li 《Geo-Marine Letters》2005,25(5):300-305

Magnetic properties were measured on 370 vibrocores obtained from the outer continental shelf of the East China Sea, with the aim of reconstructing environmental changes during the late Quaternary. High SIRM/χ values (>25 kA m⁻¹) found in stiff muds of late Pleistocene age suggest the presence of magnetic iron sulfides, especially greigite. Framboidal aggregates of greigite were further identified by scanning electron microscopy (SEM) and attached energy dispersive X-ray (EDAX) analyses, as well as powder X-ray diffraction (XRD) analyses of the magnetic separates. The occurrence of magnetic iron sulfides indicates the complex oxidation–reduction of the stiff muds, resulting from exposure and inundation during the last glacial maximum (LGM) and the post-glacial transgression, respectively.  相似文献