Gradients in coral reef communities exposed to muddy river discharge in Pohnpei,Micronesia     

Yimnang Golbuu  Katharina Fabricius  Steven Victor  Robert H. Richmond 《Estuarine, Coastal and Shelf Science》2008

This study analyzed how coral communities change along a gradient of increasing exposure to a mud-discharging river in the Enipein Catchment, Pohnpei, Micronesia. Using video transects, we quantified benthic communities at five sites along a gradient moving away from the river mouth towards the barrier reef. The most river-impacted site was characterized by a high accumulation of mud, low coral cover and low coral diversity. Although coral cover leveled off at ∼400 m from the river mouth to values found at the outer-most sites, coral diversity continued to increase with increasing distance, suggesting that the most distant site was still impacted by the river discharges. Fungiidae, Pavona, Acropora, Pachyseris and Porites rus all significantly increased in cover with distance from the river, while Turbinaria decreased. The combined presence and abundance of these six species groups, together with coral species richness, may help to indicate the effects of terrestrial runoff in similar runoff-exposed settings around Micronesia, whereas coral cover is not a sensitive indicator for river impact. Coral reefs are important resources for the people of Pohnpei. To prevent further degradation of this important resource, an integrated watershed approach is needed to control terrestrial activities.  相似文献   

Micromorphological features of Paleo-Stagnic-Anthrosols at archaeological site of Sanxingdui,China     

Yurong He  Chengmin Huang  Xiangming Xu  Yanqiang Wang  Xiubin He 《山地科学学报》2008,5(4):358-366

The archaeological site of the Sanxingdui may date back as far as 5,000 years ago. The typical profiles of Palaeo-Stagnic-Anthrosols near the ancient site were selected, which aimed to identify diagnostic horizons employing methodology of soil taxonomic classification and to reveal the micromorphological properties of the paleosols. Under long-term anthropogenic mellowing, the discernible differentiation between anthrostagnic epipedon and its subhorizons as well as hydragric horizon and its subhorizons occurred in Paleo-Stagnie-Anthrosols at the archaeological site of the Sanxingdui. The mieromorphological properties diversified among each specific diagnostic subhorizon, e.g., the developed microstructure in cultivated subhorizon within anthrostagnic epipedon, closely arranged particles and considerable micropores beneficial to both of water conservation and filtration in plow subhorizon within anthrostagnic epipedon, and automorphic optical-orientation clays and calcareous corrosion in hydragric horizons. The findings above of micromorphological features related with diagnostic horizons are significant for soil taxonomic classification.  相似文献   

帘蛤科4种养殖蛤群体遗传多样性和种间关系的fAFLP分析          下载免费PDF全文

彭永兴  程汉良  夏德全  吴婷婷  孟学平  吉红九  董志国 《海洋科学》2008,32(1):45-51

利用荧光标记扩增片段长度多态性(fAFLP)技术对文蛤(Meretrix meretrix)、青蛤(Cyclina sinensis)、菲律宾蛤仔(Ruditapes philippinarum)和硬壳蛤(Mercenaria mercenaria)4种帘蛤科贝类的群体遗传多样性和种间关系进行了研究。选择EcoRⅠ/MseⅠ进行酶切,使用6个E 3/M 3引物组合进行扩增,共获得1 096个位点,多态位点比率95.1%,片段长度50~456 bp。其中,文蛤、青蛤、菲律宾蛤仔和硬壳蛤分别得到681,715,702和694个位点,相应的多态位点比率为76.8%,81.7%,83.0%和75.1%,得到17个种特异性位点,可作为4物种特征标记。分析了群体遗传相似系数和遗传多样性指数以及种间遗传相似系数。结果表明,硬壳蛤群体遗传相似系数最高(0.670 9),遗传多样性指数最低(0.236 0);菲律宾蛤仔群体遗传相似系数最低(0.592 5),遗传多样性指数最高(0.261 8);根据遗传相似系数采用UPGMA法构建了4物种32个体的聚类图,表明文蛤与菲律宾蛤仔遗传关系最近,青蛤与其他3物种遗传关系较远。  相似文献   

Genetic diversity analysis with ISSR PCR on green algae Chlorella vulgaris and Chlorella pyrenoidosa     

沈颂东 《中国海洋湖沼学报》2008,26(4)

In the present study, genetic polymorphism and diversity in unicellular clones of Chlorella vulgaris Beijerinck and Chlorella pyrenoidosa Chick were studied with Inter Simple Sequence Repeats PCR (ISSR PCR). Samples including four clones of C. vulgaris and three clones of C. pyrenoidosa were purified by single-clone-choice method. For four C. vulgaris unicellular clones, the total number of the bands scored for 18 primers was 298; and the number of the polymorphic bands was 118, of which 39.6% were polymorphic. The size of PCR products ranged from 200 to 2 500 bp. The total number of bands scored for 18 primers, the number of polymorphic bands and the percentage of three C. pyrenoidosa unicellular clones was 194.83 and 30.8%, respectively. POPGENE analysis show that the average Nei genetic diversity (h *) and Shannon index of diversity (I *) in the four C. vulgaris unicellular clones was 0.2181 and 0.3208, respectively, which is slightly higher than those of the three C. pyrenoidosa unicellular clones (0.190 3 and 0.274 8), which agreed with the percentage of polymorphic bands in the mixed samples of the two species. The results suggest that ISSR is a useful method to Chlorella for intra-species genetic analysis.  相似文献   

牙鲆GHR基因Promoter区微卫星序列多态性与生长性状关系的初步研究   总被引：2，自引：0，他引：2  

倪静  尤锋  于深辉  张培军  徐冬冬  吴志昊  文爱韵  徐永立 《中国海洋大学学报(自然科学版)》2008,38(5)

采用牙鲆GHR基因5'端Promoter区的1个微卫星标记,对胶南和日照2个牙鲆养殖群体进行了群体遗传多样性的研究,并探索该基因多态性位点与牙鲆生长性状之间的相关性.结果表明,2个群体在该座位的等位基因数为12和9个,有效等位基因数为6.26和5.04个,多态信息含量为0.84和0.80.2个群体该座位的Hardy-Weinberg遗传偏离指数均为正值,并没有显示出杂合子缺失,但各基因型分布频率都在一定程度上偏离Hardy-Weinberg平衡(P<0.01).连锁分析中发现,在胶南群体中,IM基因型对应的个体在全重、全长、体长、头长、体高和眼径形态学数据中均是最大的;在日照群体中,BC基因型对应的个体在全重、全长、体高、尾柄高、尾柄长和眼径数据中均是最大的;而CJ基因型对应的个体在体长和头长这两组数据中是最大的.该结果为研究GHR基因的变异对鱼类生长发育的影响及探索将该基因作为生长遗传标记的可行性奠定了实验基础.  相似文献   

丹江口水库赤眼鳟(Squaliobarbus curriculus)遗传多样性的RAPD和ISSR分析   总被引：1，自引：0，他引：1       下载免费PDF全文

杨太有  关建义  陈宏喜  汪亚平 《海洋与湖沼》2008,39(2):157-161

利用RAPD和ISSR两种分子标记技术,分析了丹江口水库野生赤眼鳟30个个体的遗传多样性。用11个RAPD引物对其基因组DNA进行扩增,共获得101个重复性好且谱带清晰的扩增位点,片段大小在100—3000bp之间,其中多态性位点63个,多态位点比例为62.38%;个体间遗传距离在0.1049—0.3417之间,平均为0.1742。用10个ISSR引物共检测到88个位点,其中多态性位点61个,多态位点比例为69.32%;个体间遗传距离在0.1088—0.3847之间,平均为0.1907。结果显示,丹江口水库野生赤眼鳟群体的多态位点比例和平均遗传距离均较大,说明其有较高的遗传多样性。  相似文献   

杭州湾上海石化沿岸潮间带生态环境分析   总被引：1，自引：0，他引：1  

张进龙 《海洋湖沼通报》2008,(1):74-79

通过对1993～2002年杭州湾上海石化沿岸潮间带底栖动物群落结构的分析,得出上海石化处理达标后排放的工业废水对此段潮间带生态环境影响的范围和程度。自2002年到现在为止,本潮间带的底栖动物群落结构呈现一种适应性广、耐污染的结构组成.其生物多样性指数值在2.00～3.50之间。  相似文献   

闽东沿岸2004～2006年浮游植物生态特征研究     

丁页  林元烧  曹文清  杨圣云  李乃姜 《台湾海峡》2009,28(3):360-369

根据闽东海洋环境监测中心2004年-2006年阂东沿岸生态调查的资料，分析和研究了闽东沿岸浮游植物的生态特征．共鉴定出浮游植物的种类3个门39属共134种，其中硅藻门的种类占总种数的80％，为该调查海域主要门类．主要优势种是中肋骨条藻（Skeletonema costatum）、旋链角毛藻（Chaetoceros curvisetus）、尖刺拟菱形藻（Pseudo—nitzschia pungens）和丹麦细柱藻（Leptocylindrus danicus）等．浮游植物的丰度分布，呈现由调查海域东北侧向西南侧、由近岸向远岸减少的空间特征，夏季高、春季低的季节变化特点，并且有逐年减少的年际变化趋势．本调查海域浮游植物多样性指数较高，群落较稳定．  相似文献   

Characterization of marine microplankton communities of Qingdao coastal areas using randomly amplified polymorphic DNA（RAPD）   总被引：1，自引：1，他引：0  

GAO Shan  HU Xiaozhong  CHEN Zigui  XU Henglong  YI Zhenzhen  LIN Xiaofeng  LIJiqiu 《海洋学报(英文版)》2009,28(1)

Microplankton communities of three coastal sites of Qingdao, Shandong Province, China were investigated using RAPD (random amplified polymorphic DNA) molecular markers and morphological observations. Eight RAPD-primers were selected to amplify the DNA polymorphy. The genetic distances inferred from the pairwise similari-ties were calculated for the phylogenetic tree construction. Meantime, the traditional microscopic determination, a way of visualizing the species composition, was performed to detect the major taxa of microplanktons from all samples. Results showed that: (1) the band sharing index values were in the range of 0. 504 2-0. 763 2 among samples from the same sampling site at different time scales, while 0.406 5-0.685 7 among the samples from different stations at the same time scales, indicating that spatial variations of microplankton communities were more pronounced than temporal ones; (2) samples from the same station basically clustered together, cor-responding to the geographic distribution of the sampling sites; (3) diversity derived from genetic and morpho-logical data did not correspond with each other well.  相似文献   

Biodiversity patterns of free-living marine nematodes in a tropical bay: Cienfuegos, Caribbean Sea   总被引：2，自引：0，他引：2  

M. Armenteros  A. Ruiz-Abierno  R. Fernndez-Garcs  J.A. Prez-García  L. Díaz-Asencio  M. Vincx  W. Decraemer 《Estuarine, Coastal and Shelf Science》2009,85(2):179-189

Spatial and temporal biodiversity patterns of free-living marine nematodes were studied in Cienfuegos Bay, a tropical semi-enclosed basin in the Caribbean Sea. Taxonomic (to species level) and functional (biological trait) approaches were applied for describing the assemblage structure and relating it to abiotic environment based on a sampling scheme in six subtidal stations and three months. Biological trait approach added relevant information to species pattern regarding relationships between diversity patterns and the abiotic environment. The most common morphotypes were deposit feeding nematodes, with colonising abilities of 2–3 (in a scale from 1 to 5), tail conical cylindrical or filiforme and body slender; and their abundance were correlated with depth, organic matter and silt/clay fraction. In spite of a high turnover of species, functional diversity of assemblages did not change notably in space and time. A result probably due to sampling of the habitat pool of species and to low heterogeneity of the studied muddy bottoms. Chemical pollution (organic enrichment and heavy metals) and hydrodynamic regime possibly drove the biodiversity patterns. Spatial distribution of assemblages support the existence of two well differentiated basins inside the bay, the northern basin more polluted than the southern one. The low hydrodynamic regime would determine a poor dispersion of nematodes resulting in high spatial variance in the assemblage structure; and also the associated hypoxic conditions and pollutants in sediments can explain the dominance of tolerant nematode species such as Daptonema oxycerca, Sabatieria pulchra, Terschellingia gourbaultae, and Terschellingia longicaudata. A comparison of spatial–temporal patterns of biodiversity between Cienfuegos Bay and other semi-enclosed bays in temperate regions suggests several similarities: nematode assemblages are strongly influenced by anthropogenic disturbance, temporal trends are weak or overridden by spatial ones, and few cosmopolitan genera/species tolerant to pollution and hypoxic conditions are dominant.  相似文献