A fuzzy distinguishability on species composition similarities of pelagic fishes in different years in the southern Taiwan Strait     

Zhang Chengmao  Fang Shuimei  Yang Shengyun 《海洋学报(英文版)》2001,20(4):575-583

I\rnooUcrIoxThe drpdric fish species cor-npositlon is an imPOrtant element 1n the study of fish ecologyand plays an important guiding role ln fishery preduction and roouLrces rnanagement. Lin(l988) and Zhang (1994 and l995) have studied the simi1drities of mpulation COtwsition ofame s1ngle species of different yea-rs including hairtail Trichuras haumee and yellDw cndertwinena cmi. But no rePOrt is available on the discridrination of the sidrildrities amongmuLlt1ple sPecies composition of…  相似文献   

Atmospherically-promoted photosynthetic activity in a well-mixed ecosystem: Significance of wet deposition events of nitrogen compounds   总被引：1，自引：0，他引：1  

C. Boulart  P. Flament  V. Gentilhomme  K. Deboudt  C. Migon  F. Lizon  M. Schapira  A. Lefebvre 《Estuarine, Coastal and Shelf Science》2006,69(3-4):449

Wet atmospheric deposition of dissolved N, P and Si species is studied in well-mixed coastal ecosystem to evaluate its potential to stimulate photosynthetic activities in nutrient-depleted conditions. Our results show that, during spring, seawater is greatly depleted in major nutrients: Dissolved Inorganic Nitrogen (DIN), Dissolved Inorganic Phosphorus (DIP) and Silicic acid (Si), in parallel with an increase of phytoplanktonic biomass. In spring (March–May) and summer (June–September), wet atmospheric deposition is the predominant source (>60%, relative to riverine contribution) for nitrates and ammonium inputs to this N-limited coastal ecosystem. During winter (October–February), riverine inputs of DIN predominate (>80%) and are annually the most important source of DIP (>90%). This situation allows us to calculate the possibility for a significant contribution to primary production in May 2003, from atmospheric deposition (total input for DIN ≈300 kg km⁻² month⁻¹). Based on usual Redfield ratios and assuming that all of the atmospheric-derived N (AD-N) in rainwater is bioavailable for phytoplankton growth, we can estimate new production due to AD-N of 950 mg C m⁻² month⁻¹, during this period of depletion in the water column. During the same episode (May 2003), photosynthetic activity rate, considered as gross primary production, was estimated to approximately 30 300 mg C m⁻² month⁻¹. Calculation indicates that new photosynthetic activity due to wet atmospheric inputs of nitrogen could be up to 3%.  相似文献   

台湾海峡西部柱状沉积物粘土矿物的分析   总被引：4，自引：0，他引：4  

游仲华  唐锦龙 《台湾海峡》1993,12(1):1-7

根据台湾海峡西部10个柱102个样品的X 射线衍射等分析,鉴定了该区粘土矿物组合与含量变化,分析了其与沉积环境的关系.结果表明,该区粘土矿物组合大多数站位以伊利石含量占首位,绿泥石和高岭石次之,且含少量蒙脱石;伊利石含量随距岸、水深的增加而递增,高岭石则反之;蒙脱石含量与火山活动密切相关,绿泥石含量呈斑块状分布;775和819号站有典型的陆相层,为早玉木冰期的“台湾陆桥”或“东山陆桥”提供有力证据.  相似文献   

台湾海峡1997年8月至1999年8月份海水光学衰减系数的分布特征   总被引：2，自引：0，他引：2  

张彩云  商少平  胡建宇  陈照章 《台湾海峡》2001,20(1):127-131

利用1997－1999年间8月份台湾海峡的实测资料，分析了海水光学衰减系数的垂直分布类型、水平分布特征。结果表明，台湾海峡海水光学衰减系数的垂直分布类型主要分为5种，大部分随深度而递增；光学衰减系数等值线基本与岸线平行，水平梯度自北向南、自近岸向外海递减，近岸等值线密集，而外海稀疏；影响台湾海峡光学衰减系数的主要因素是县浮物质（主要含浮游生物）和海流运动。  相似文献   

弯睾鲫吸虫[Carassotrema flecterotestis(Zhukov,1971)comb.nov.]及其毛蚴发育观察     

于水舟  彭文峰  刘升发 《台湾海峡》2005,24(1):97-103

本文对取自台湾海峡棱鮻 (Lizacarinatus)消化道的弯睾软穴吸虫 (HapalotremaflecterotestisZhukov, 1971)进行重新描述,并对其毛蚴的体外发育进行观察.根据Yamaguti(1971)区分单孔科 (Haploporidae)和叉盘科 (Waretrematidae)的标准,同意李敏敏(1984)将其从单孔科移出并入叉盘科.在与叉盘科已知属比较后,我们发现该吸虫除睾丸形状外,其他主要特征与鲫吸虫属 (CarassotremaPark, 1938)的相似.因此,我们拟将其作为后者的同物异名,并将该吸虫重新命名为弯睾鲫吸虫 [Caras sotremaflecterotestis(Zhukov, 1971)comb. nov. ].实验结果表明:在室温 7~24℃(均值为 15. 3℃)条件下,其虫卵从单个卵细胞到毛蚴孵出共需 12d.  相似文献   

吕宋海峡输送年际变异数值研究   总被引：1，自引：0，他引：1  

姜涛  黄洪辉  王文质 《热带海洋学报》2006,25(5):13-20

利用MITgcm数值模式1980—2001年的常规模拟输出数据,研究了吕宋海峡22年平均的体积、热量和盐量输送随深度的变化,并利用小波变换分别分析了吕宋海峡3个层次(0—145、145—915、915—1 837m)体积和热量输送的年际变化,主要结果如下。(1)在吕宋海峡1 837m层以下,仍有一定数量的西北太平洋海水(体积和盐)西向输送到南海;(2)915—1 615m层的年际体积输送的变化趋势与上两个层次(0—145m、145—915m)类似,但是在某些ENSO时期(如1985、1987、1991—1995年),其年际变化与145—915m层年际变化的位相相反;(3)吕宋海峡年际体积(热量)输送的小波谱图较明显地反映出ENSO现象对吕宋海峡不同层次的输送均产生一定影响。145—915m层次的吕宋海峡年际体积输送与ENSO现象相关性显著。  相似文献   

Inhomogeneous substrate analysis using EM300 backscatter imagery   总被引：2，自引：0，他引：2  

Yves Le Gonidec  Geoffroy Lamarche  Ian C. Wright 《Marine Geophysical Researches》2003,24(3-4):311-327

Backscatter reflectivity from multibeam echo-sounders provides a powerful tool to efficiently characterize seafloor substrates. A comprehensive EM300 bathymetric and backscatter survey has been completed of Cook Strait, in central New Zealand. This paper presents a detailed analysis of the realtime corrections applied to the raw EM300 multibeam data and additional corrections required to compute angular variations of the backscatter strength. The corrections, including the local absorption coefficient, the influence of seafloor topography and sound refraction in the water column, are determined for different Cook Strait seafloor substrates. Modifying MB-System software code, we extracted the backscatter signal parameters in order to quantify the raw backscatter strength and apply additional processing. Profiles of backscatter strength versus incidence angle were computed for a variety of sites characterized by flat seafloor and homogeneous substrates, and for which ground-truth data were available. For each homogeneous site, different but characteristic backscatter profiles are observed that can be interpreted in terms of sediment facies. To analyze heterogeneous substrates, we present a statistical technique, based on a 3-dimensional distribution of (incidence angle, backscatter strength) couples that preserves geological information of the substrate components. This analysis, using backscatter data acquired on a submarine volcano, north of New Zealand, clearly differentiates soft sediments and lava flows within a heterogeneous substrate.  相似文献   

The influence of hydrography on the distribution of phytoplankton in the southern Taiwan Strait     

R. Huang 《Estuarine, Coastal and Shelf Science》1988,26(6)

During the period August 1985 to May 1986, phytoplankton in the southern Taiwan Strait was collected and studied for distributional variability in relation to hydrography. The results indicated that maximum standing crops of phytoplankton occurred in October and May due to the outgrowth of certain species of diatoms and blue-green algae. The majority of phytoplankton appeared in the water in the top 25 m and occurred in distinct clusters under the influence of water movement. Multivariate analysis indicated that hydrographic parameters, which accounted for the variability of phytoplankton distribution, varied seasonally. Vertical, spatial and temporal variabilities were also apparent. The close relationship between hydrography and algal distribution justifies the use of variations in the phytoplankton population as a useful tracer of water movement.  相似文献   

台湾海峡表层沉积物中重矿物特征及其物质来源   总被引：15，自引：0，他引：15  

陈华胃 《台湾海峡》1993,12(2):136-144

台湾海峡重矿物平均分布0.95%,其分布由西岸向东岸递减;由北部经台湾浅滩朝粤东方向缓慢递减。碎屑矿物46种,以角闪石、绿帘石、磁铁矿、钛铁矿、褐铁矿和片状矿物为主,它们占重矿物含量的67%。据主要重矿物含量将海峡分成8个矿物组合区。碎屑矿物来自海峡两岸基岩,通过河流搬运入海,有部分片状矿物为海峡以北的物质随浙闽沿岸流进入海峡而沉积。其海绿石是台湾西岸、澎湖岛第三系或第四系含海绿石岩层剥蚀后搬运入海沉积而成的。台湾浅滩的残留沉积物为晚更新世低海面时期的河口滨海相沉积物。由于处在开放的海洋环境,至今没有接受现代沉积。残留沉积物中的磁铁矿、钛铁矿、锆石等重矿物相对富集,含量高于近源海域,有可能赋存浅海砂矿。  相似文献   

The Luzon Strait transport variations during 1997～2000     

JIANG Tao  LIU Yun  WANG Wenzhi 《海洋学报(英文版)》2004,23(1):83-90

Based on the output data from 1997 to 2000 obtained by the MITgcm's (general circulation model) adjoint assimilation method, volume, heat and salt transports through the Luzon Strait are calculated. The results indicate that there are obvious different characteristics between 1997 and 1998～2000 on the transports through the Luzon Strait. During 1997, theLuzon Strait had a mean net westward transport of 3.93×10⁶ m³/s with a maximum transport of 7.34×10⁶ m³/s in October. During 1998～2000, the Luzon Strait possessed an annual mean eastward transport of 0.93×10⁶, 1.80×10⁶ and 1.00×10⁶ m³/s respectively with a maximum eastward transport of 4.10×10⁶/3.31×10⁶ m³/s in July 1998/1999 and 2.06×10⁶ m³/s in April 2000, respectively. Moreover, the transports in 1997 indicated a difference from the other years, i.e.,that the ranges of westward inflows expanded more obviously to north of the Luzon Strait and downwards exceedingthose of the other years. The westward inflows expanded horizontally to the north part of the Luzon Strait until 21°N.  相似文献