Distribution and Seasonal Variability of Organic Matter in a Small Eutrophicated Salt Lake     

《Estuarine, Coastal and Shelf Science》2000,51(6):705

Distribution and seasonal variability of dissolved organic carbon (DOC) and surface active substances (SAS) were studied along the depth profile (15 m) in a small eutrophicated and periodically anoxic sea lake (Rogoznica Lake, Eastern Adriatic coast) in 1996 and 1997. The range of DOC concentrations was characteristic for productive coastal marine ecosystems (60% of samples in the range of 1–2 mg l⁻¹and 40% between 2 and 3 mg l⁻¹). Distribution of SAS concentrations was uniform and shifted toward higher concentrations in comparison to other coastal areas in the Adriatic Sea. Eutrophication in the lake is generated by nutrient recycling under anaerobic conditions. Systematically higher concentrations of chlorophyll a, DOC and SAS were determined at the chemocline in the bottom layer (10–12 m) than in the upper water layer (0·5–2 m). Seasonal variability of organic matter was discussed regarding distributions of microphytoplankton (cells >20 μm) and photosynthetic pigments as well as oxygen and salinity changes along the depth profile. The dissolved oxygen saturation reaching up to 300% in the water layer between 8 m and 10 m depths in May and June 1996, was correlated with enhanced concentrations of phytoplankton biomass (reflected as chl a and b, fucoxanthin, peridinin, zeaxanthin) and increased concentrations of DOC and SAS.  相似文献   

Food and habitat resource partitioning between three estuarine fish species on the Swedish west coast     

Staffan Thorman 《Estuarine, Coastal and Shelf Science》1983,17(6)

In 1978 the food and habitat resource partitioning of three small and common fish species, viz. Pomatoschistus microps (Krøyer), Gasterosteus aculeatus (L.) and Pungitius pungitius (L.) were studied in river Broälven estuary on the Swedish west coast (58°22′N, 11°29′E). The area was divided into three habitats, based on environmental features. In July, September, and October stomach contents and size distribution of each species present were analysed.In July there was high food and habitat overlap between the species. Interference interactions probably occurred between some size classes of P. microps and the other two species. P. pungitius was exposed to both intra- and interspecific interactions. In September the food and habitat overlaps between G. aculeatus and P. pungitius were high, while both had low food and habitat overlaps in relation to P. microps. Interactions between G. aculeatus and P. pungitius were probably influenced by more severe abiotic conditions in one habitat, which caused lower abundances there, and higher abundances in the other two habitats. In October no interactions were observed. These results indicate that competition for food at least temporarily determines the species distribution in a temperate estuary, and that estuarine fish populations are sometimes food limited.  相似文献   

渤海莱州湾南岸第四纪地下卤水演化的地球化学模拟   总被引：13，自引：0，他引：13  

王珍岩  孟广兰  王少青 《海洋地质与第四纪地质》2003,23(1):49-53

渤海莱州湾南岸地区赋存有大量的地下卤水，许多研究者认为这些水是第四纪地质历史时期古海水经强烈蒸发浓缩后埋藏而成的，运用反向地球化学模拟理论，选用美国地质调查局（USGS）提供的PHREEQC（1997）地球化学模拟软件，对莱州湾南岸昌邑廒里501孔各层卤水的水化学演化过程进行模拟，研究结果表明，该地区的地下卤水是由古海水经强烈蒸发浓缩后被沉积物理藏，并在赋存过程中发生水－岩相互作用，使地下水出现方解石，石膏及CO2气体的过饱和析出。并伴随与沉积物发生K^ ,Na^ ,Mg^2 ,Ca^2 之间的阳离子交换反应。其中的浅层地下卤水还受到地表盐后排放卤水的侵染。  相似文献   

大连沿海蓝藻植物新记录     

张淑梅 《中国海洋大学学报(自然科学版)》2002,32(1):85-88

报道 6种产自大连沿海的蓝藻植物 ,分别为栖石隐杆藻 Aphanothece saxicola Naeg.、色合藻 Chroothece littorinae Tseng et Hua、附钙管鞘藻 H ormathonema ep ilithicum Ercegovic、短丝颤藻 Oscillatoria brevis Kuetzing、丰裕颤藻 Oscillatoria limosa(Dillw.) Ag.ex Gom.、中央席藻海生变种 Phormidium naveanum var.marina Tseng et Hua,它们均是大连沿海新记录。  相似文献   

广西沿海年极值波高分析   总被引：2，自引：0，他引：2  

夏华永  李树华 《热带海洋学报》2001,20(2):1-7

经分析发现广西沿海极值波高不符合用的P－Ⅲ型分布，并分析了其符合的分布函数，结果表明对Weibull分布符合最好，为解决Weibull分布参数难于确定的问题，引入了共轭梯度法计算其参数，最终计算了多年一遇极值波高。  相似文献   

海岸趋势面应用技术比较分析 ——以黄河三角洲海岸为例     

王岩峰  崔承琦 《中国海洋大学学报(自然科学版)》2001,31(1):95-102

依据黄河三角洲潮滩海岸准同步断面实测地形点数据，进行地貌趋势面的多种技术方法处理。多项式回归方法能把握潮滩海岸三维形态的总趋势，忽略全部次一级形态特征；Nearest Neighbor方法、Kriging方法和Triangulation W/线性插值方法均可以显示总趋势面上次一级形态——潮滩海岸沟盆体系。其中Triangulation W/线性插值法计算出的局部特征十分明显，但边界会产生很大误差。Kriging方法和NearestNeighbor方法在边界上处理得较好，Kriging方法图象过渡得非常自然，而Nearest Neighbor方法相对保留了矩形的处理特征。趋势面分析表明，潮沟—潮盆体系的形成与发展是表征黄河三角洲潮滩海岸时空谱系发育进程的重要指标。  相似文献   

福建沿岸海域赤潮发生特点及防治措施   总被引：17，自引：2，他引：17  

许珠华  侯建军 《台湾海峡》2006,25(1):143-150

根据多年来福建沿岸海域发生赤潮的情况及相关资料，概述了该海域赤潮发生的主要趋势、时间、区域、种类和危害等特点，分析和讨论了赤潮发生的自然因素和人为因素；并指出赤潮防灾和减灾工作中存在的主要问题是海洋综合管理力量薄弱，海洋法律法规不够健全，海洋执法能力有待加强，海洋事业经费投入不足．在此基础上提出了防治福建沿岸海域赤潮灾害的如下措施和建议：进一步调查和研究赤潮发生的类型并分析其主要成因；建立健全福建省近岸海域环境监测网络和海洋环境监测系统，大力开展具有福建区域特色的赤潮生物及其有害赤潮发生机理等科学研究；控制陆源污染，减少含氮污染物的排放总量和入海量，提倡和推广使用农家肥，提高生活污水的处理效率；认真研究和分析港湾的环境容量，合理开发福建的海水养殖业；加强围填海等涉海工程对海水动力学影响的研究，以及加强对船舶压仓水等带来外来赤潮生物影响的研究等．  相似文献   

珊瑚礁海岸侵蚀的研究方法     

薛春汀 《海洋地质与第四纪地质》2002,22(2):121-125

珊瑚礁海岸海滩和礁坪是海岸作用是活跃的部分，也是近几十年来与海岸发育，海岸侵蚀联系最密切的部分，这一部分高潮时被淹没，低潮时完全出露或大部分出露，使得在此进行地质填图成为可能，这样的地质图可以提供许多信息，如沉积物粒度分布规律，沉积物来源和搬运方向，海滩岩所指示的古海岸线位置，人类活动特别是海岸工程对沉积物分布的影响以及海岸线的变化过程和趋势，在礁坪上开挖的人工水道内测流，能够了解水流的性质以及是否有足够的速度搬运沉积物，从而了解人工水道对海岸的影响和预测海岸的状态，这些方法也可以用于大陆泥质和砂质第岸侵蚀的研究。  相似文献   

近50年来莱州湾南岸气候变化及环境效应   总被引：2，自引：0，他引：2  

邱志高  丰爱平  谷东起  吴桑云 《海岸工程》2006,25(2):55-60

利用实测的地面气象资料,对近50年来莱州湾南岸的气候变化特征进行了分析。发现自1954年以来莱州湾南岸地区气温持续升高;年均降雨量处于波状起伏状态,1970年以前为多雨期,1970-1990年为少雨期,此后降雨量又有所增加。气温和降水量的变化,加上人类活动不断增强,导致莱州湾南岸海水入侵快速发展,台风风暴潮发生频次和强度有所增加,滨海生态系统发生变化。  相似文献   

Distribution of macrobenthic assemblages along a marine gradient in Mediterranean eutrophic coastal lagoons     

Francesco Rossi  Alberto Castelli  & Claudio Lardicci 《Marine Ecology》2006,27(1):66-75

Coastal lagoons can be characterised by strong environmental changes along the outer marine‐inner brackish gradient, which are reflected in the patterns of distribution of organisms and composition of assemblages. Close to the sea the assemblages are dominated by marine animals, while in the innermost confined areas, there would be estuarine taxa and organisms typical of organically‐enriched areas. During the last decades, human impact has been severe in these habitats and has often profoundly altered the distribution of animals and plants along the gradient. In this study we have analysed the distribution of macrofauna along the outer marine‐inner brackish gradient in five Italian lagoons, affected by severe human disturbance on the Adriatic, Tyrrhenian and Sardinian coasts. We aimed to measure changes in the composition of assemblages according to the distance from the sea, consistent among lagoons and time, after the occurrence of eutrophication, repeated distrophic crisis and other human interventions. We considered existing data from campaigns done during 1994, 1995 and 1999. We arranged different datasets according to the available data, in order to measure the spatial distribution of macrofauna genera with distance from the sea and through time. Analyses showed differences among assemblages related to the gradient. Nevertheless, the species characterizing the assemblages were all typical of organically‐enriched areas, which testified to an impoverishment of diversity and functioning of all these systems.  相似文献