Potential bioeconomic impact of reduced mortality of codend escapees of the shrimp fishery in the Davis Strait     

Christensen  Steen 《ICES Journal of Marine Science》1995,52(5):843-851

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Growth patterns of three cohorts of Atlantic cod larvae (Gadus morhua L.) studied in a macrocosm     

Folkvord  Arild; Oiestad  Victor; Kvenseth  Per Gunnar 《ICES Journal of Marine Science》1994,51(3):325-336

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Analysis of size spectra off northwest Africa: a useful indicator in tropical areas?   总被引：1，自引：1，他引：1  

Stobberup  Kim A.; Inejih  Cheikh A.O.; Traore  Sory; Monteiro  Carlos; Amorim  Patricia; Erzini  Karim 《ICES Journal of Marine Science》2005,62(3):424-429

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Seagrass landscapes and their effects on associated fauna: A review   总被引：1，自引：2，他引：1  

Christoffer Bostrm  Emma L. Jackson  Charles A. Simenstad 《Estuarine, Coastal and Shelf Science》2006,68(3-4):383

Seagrasses comprise some of the most heterogeneous landscape structures of shallow-water estuarine/marine ecosystems in the world. However, while knowledge at the molecular, organism, patch and community scale is pervasive, understanding of seagrass landscape ecology is more fragmentary and has not been synthesized. The growth and recruitment dynamics of seagrasses as well as man-made and/or natural disturbances create complex spatial configurations of seagrass over broad (metres to kilometres) spatial scales. Hence, it is important to identify mechanisms maintaining and/or threatening the diversity-promoting function of seagrass meadows and to understand their effects on benthic populations and communities. Although landscape ecology has recently become more integrated into seagrass research, our understanding of animal responses to variability in seagrass landscape structure is still fragmentary. By reviewing the literature to date, this paper evaluates studies on seagrass landscape ecology, testing the general null hypothesis that concepts developed in terrestrial settings can be generalized across landscapes, and (a) presenting definitions and terms used in seagrass landscape ecology, (b) reviewing geographical patterns of seagrass landscape studies to identify possible key regions and target species, (c) evaluating different methodological approaches, (d) describing the spatial and temporal scales used to describe organism responses to seagrass landscape structure, and (e) placing seagrass landscapes into an applied context.  相似文献   

Gradient responses of epilithic diatom communities in the Baltic Sea proper   总被引：1，自引：0，他引：1  

Anna Ulanova  Pauli Snoeijs   《Estuarine, Coastal and Shelf Science》2006,68(3-4):661

Diatom communities and assemblages are widely used as indicators of ecological change in aquatic environments and for reconstructing palaeo-environments. Good calibration data sets, directly linking changes in diatom composition to environmental factors, are needed for building reliable gradient models with high indicative value. Such models have a broad applicability because most diatom species have cosmopolitan distributions. This paper presents community analyses of brackish-water diatoms living on submerged stones in four areas of the Baltic Sea proper along the Swedish coast. The communities on the stones were composed of epilithic, epiphytic, epipelic, epipsammic and occasionally some pelagic species. Altogether, 158 quantitative samples were taken at 41 sites between 23 April and 11 May, 1990, and the data set contained 300 diatom taxa belonging to 75 genera. Species data were analysed with principal components analysis (PCA) and environmental factors were fitted passively by multiple regression analysis on the ordination results. Differences in community composition could be explained by variation in salinity (which was correlated with N:P and Si:P ratios and the occurrence of macroalgae on the stones), nutrient concentrations and variation in exposure to wave action (which was correlated to the occurrence of soft bottoms around the stones, water temperature and the occurrence of sand grains and macroalgae on the stones). Separate analyses for small taxa (cell biovolume <1000 μm³), for large taxa (cell biovolume ≥1000 μm³) and for small and large diatom taxa together showed that diatoms of different size classes respond differently to environmental variation.  相似文献   

巢湖沉积物粒度特征与沉积环境   总被引：9，自引：0，他引：9  

顾成军  戴雪荣  张海林  何小勤 《海洋地质前沿》2004,20(10):10-13

利用巢湖湖底柱样沉积物的粒度资料分析了巢湖湖底沉积物粒径的组成、大小等粒度特征；初步探讨了柱样采样点位置的沉积环境及其沉积过程，以期能为巢湖流域恢复过去环境变化提供参考。通过对沉积物粒度实验分析发现，巢湖靠近河口地区的沉积物粒度在深度上变化幅度大，颗粒物相对较粗，而在湖心位置，沉积物随深度变幅小、连续性好，沉积物的颗粒细。两者的差别分别反映了它们之间不同的沉积环境。  相似文献   

黄河三角州沿岸及相邻渤海海域碳酸盐研究(英文)   总被引：2，自引：0，他引：2  

杨作升  王兆祥  瞿建忠  郑爱芬 《中国海洋大学学报(自然科学版)》1989,(3)

对黄河三角州陆地上河道,河口、潮间带及毗邻渤海海域沉积物中的碳酸盐含量作了分析,在此基础上划分出含量不同的沉积区和亚区。沉积区的划分和其物源有十分良好的对应关系,同一沉积区内的亚区则主要和粒度有关,从而间接反映了水动力环境与生物作用的控制性影响。黄河口沉积物中碳酸盐含量与粒度成反比,其他物源的沉积物则各不相同。黄河口及邻近渤海海域中粘土粒级和碳酸盐含量等值线反映出黄河细粒级沉积物扩散的方向、强度和范围。海洋生源沉积是影响渤海东部和中部沉积物中碳酸盐含量分布的主要因素。  相似文献   

岱海沉积物粒度特征及其古环境意义   总被引：101，自引：2，他引：101  

孙千里  周杰  肖举乐 《海洋地质与第四纪地质》2001,21(1):93-95

处于北方环境敏感带的封闭湖泊岱海，其沉积物的粒度特征反映了岱海降水、水动力搬运强度以及湖面水位高低的变化。较为丰富的降水及较强的水动力条件容易沉积成分较粗的陆源碎屑颗粒；当湖面较低时，缩短了沉积物搬运区与沉积区的距离，也容易使沉积物粗颗粒组分增加，但仅从平均粒径大小上很难时对其沉积作用形式作出判断。通过对贷海沉积物粒度频率曲线的分析，讨论了湖泊的几种可能沉积作用，区分了正常流水沉积与极端条件下风力作用以及水流与风力作用混合沉积，从而揭示了沉积时的古环境特征，在岩心12．34－14．18m段，即10．5ka前具有低湖面、气候寒冷、降水多次波动的特点。  相似文献   

珠江口初级生产力和新生产力研究   总被引：18，自引：2，他引：18  

蔡昱明  宁修仁  刘子琳 《海洋学报》2002,24(3):101-111

1996年12月和1997年8月在珠江河口湾及其毗邻海域对浮游植物生物量、初级生产力和新生产力及其环境制约机制的研究.结果表明,调查海区的叶绿素a、初级生产力和新生产力均是夏季高于冬季,冬、夏两季的平均值分别为(0.95±0.41)和(1.08±0.52)μg/dm3,(69.2±75.5)和(198.7±119.1)mg/(m2·d),(1.46±0.79)和(3.05±3.09)mg/(m3·h).冬、夏两季平均f-比分别为0.45和0.38.分级叶绿素a结果显示,冬、夏两季均以微型和微微型级分(<20μm)占优势,其对海区叶绿素a的贡献分别为796%和81.6%,对初级生产力的贡献分别为70.7%和896%.调查海区具显著的空间区域化特征,叶绿素a和潜在初级生产力的高值出现在冲淡水区的中部,向口门区和远岸区逐渐降低.现场初级生产力的高值出现在远岸区,它与复合参数B_eZ_pI₀(B_e为真光层平均叶绿素a,Z_p为真光层深度,I₀为海面光辐射强度-PAR)呈很好的正相关,说明光是研究海区初级生产力的主要限制因子.新生产力冬、夏两季的高值分别出现在交椅湾和伶仃洋西南部.  相似文献   

灰色系统在电敏感区法粒度分析曲线外推技术中的应用          下载免费PDF全文

姚胜初 《海洋科学》1993,17(3):63-66

根据TAI型库尔特计数器单管粒度分析结果,利用灰色系统建立GM(1,1)预测模型,对样品频率曲线进行外推处理,可获得小于仪器基线通道阈值颗粒的体积百分比含量,并将结果与入重-出重法测定结果进行对比,精度较高。为电敏感区法粒度分析资料的外推处理提供了新的方法。  相似文献