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71.
The source and significance of two nutrients, nitrogen and phosphorous, were investigated by a modified dilution method performed on seawater samples from the Jiaozhou Bay, in autumn 2004. This modified dilution method accounted for the phytoplankton growth rate, microzooplankton grazing mortality rate, the internal and external nutrient pools, as well as nutrient supplied through remineralization by microzooplankton. The results indicated that the phytoplankton net growth rate increased in turn from inside the bay, to outside the bay, to in the Xiaogang Harbor. The phytoplankton maximum growth rates and microzooplankton grazing mortality rates were 1.14 and 0.92 d-1 outside the bay, 0.42 and 0.32 d-1 inside the bay and 0.98 and 0.62 d-1 in the harbor respectively. Outside the bay, the remineralized nitrogen (Kr=24.49) had heavy influence on the growth of the phytoplankton. Inside the bay, the remineralized phosphorus(Kr=3.49) strongly affected the phytoplankton growth. In the harbor, the remineralized phosphorus (Kr=3.73) was in larger demand by phytoplankton growth. The results demonstrated that the different nutrients pools supplied for phytoplankton growth were greatly in accordance with the phytoplankton community structure, microzooplankton grazing mortality rates and environmental conditions. It is revealed that nutrient remineralization is much more important for the phytoplankton growth in the Jiaozhou Bay than previously believed. 相似文献
72.
Recruitment patterns of Serpula vermicularis L. (Polychaeta, Serpulidae) in Loch Creran, Scotland 总被引:1,自引:0,他引:1
Nicola D. Chapman Colin G. Moore Dan B. Harries Alastair R. Lyndon 《Estuarine, Coastal and Shelf Science》2007,73(3-4):598-606
This study aimed to contribute to conservation management of reefs of Serpula vermicularis by increasing understanding of the factors influencing larval settlement. The study was carried out in Loch Creran, which supports the most extensive known development of S. vermicularis reefs in the world. Settlement plates were deployed to examine the influence of season, depth, reef density, substrate type and orientation. Monthly deployment of plates revealed settlement of S. vermicularis to occur predominantly from mid-June to mid-October, peaking in late August to early September. Settlement of Pomatoceros spp. peaked much earlier, in late May to early June. Deployment of plates at different depths revealed a marked reduction in S. vermicularis settlement intensity between 6 and 12 m. As this corresponds with the deeper limit of the peripheral fringe of serpulid reefs in the loch, it is suggested that this limit is imposed by a depth-correlated settlement response, rather than reduction in available substrata. Comparisons of various substrata showed a preference by S. vermicularis larvae for a slate over a scallop substrate and no evidence of enhanced recruitment to occupied or unoccupied tubes of S. vermicularis, suggesting that gregarious attraction is unlikely to be a factor causing reef formation. Settlement onto the upper side of a horizontal scallop substrate was found to be insignificant in comparison with the underside or a vertically orientated scallop. Evidence for the role of light in controlling the depth and substrate-orientation preferences of S. vermicularis larvae is discussed. Based on the results of this study, recommendations are made regarding remediation of areas suffering reef damage. 相似文献
73.
人工饲料饲养的对虾肠道菌群和水体细菌区系的研究 总被引:9,自引:0,他引:9
对人工饲料饲养的凡纳滨对虾Litopenaeus vannamei成虾肠道菌群组成及其水体细菌区系组成进行了研究.分离纯化后的革兰氏阴性菌鉴定到种的水平.对虾肠道菌群主要由弧菌Vibrio spp.、希瓦氏菌属Shewnella spp.、嗜氢菌属Hydrogenophaga spp.、伯克霍尔德氏菌Burkholderia spp.、气单胞菌Aeromonas spp.、食酸菌Acidovorax spp.和芽孢杆菌Bacillus spp.组成.水体细菌区系主要包括弧菌Vibrio spp.、希瓦氏菌属Shewnella spp.、艾肯菌Empedobacter spp.、无色杆菌Achromobacter spp.和芽孢杆菌Bacillus spp..肠道菌群和水体细菌区系的优势菌是副溶血弧菌Vibrio parahaemolyticus和芽孢杆菌Bacillus spp..利用Shannon-Wiener指数进行多样性分析,发现虾肠道多样性指数(H)和均匀度(J)高于水体细菌区系,而丰度(D)较低. 相似文献
74.
Analysis of Dynamic Characteristics of Submarine Free Spanning Pipelines by Complex Damping Method 总被引:2,自引:0,他引:2
Considering the effect of the internal flowing fluid and the external marine environmental condition, the differential equation for the vortex-induced vibration (V1V) of the free spanning pipeline is derived and is discretized by the Hermit interpolation function. The free vibration equation with the damping term is solved by the complex damping method for the natural frequency, and then the effect of fluid damping on the natural frequency of the free spanning pipeline is analyzed.The results show that fluid damping has a significant influence on the damped natural frequency of the free spanning pipeline in the lock-in state, while it has little influence when the pipeline is out of the lock-in state. In the meantime,the change of the free span length has the same effect on the damped natural frequency and the undamped natural frequency. 相似文献
75.
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77.
化学生态调控对鳌山湾氮磷营养盐的影响 总被引:2,自引:0,他引:2
鳌山湾,是一个营养类型特殊的海湾,湾中基本无径流输入,呈“C”字形,封闭性较强,水较浅,湾内主要有筏式扇贝养殖和底播贝类养殖,沿岸有滩涂池塘养殖.根据1996年11月至1998年5月的调查结果得知,鳌山湾海域为贫营养海域[1,2].为探讨贫营养海域进行化学生态调控的可能性,利用鳌山湾的封闭性,根据其水交换规律[3],于1999年6月首次对鳌山湾进行了全湾规模较大的化学生态调控试验,旨在有效提高鳌山湾的营养水平,为今后在贫营养海域合理发展海水养殖业提供科学依据,获得了十分理想的效果. 相似文献
78.
皱纹盘鲍(Haliotis discus hannai Ino)和杂色鲍(Haliotis diversicolor Reeve)遗传多样性的RAPD研究 总被引:13,自引:0,他引:13 下载免费PDF全文
于 2 0 0 1年 8月— 2 0 0 2年 7月 ,选用 2 0条能产生清晰可重复扩增产物的随机引物 ,对皱纹盘鲍 (HaliotisdiscushannaiIno)、杂色鲍 (HaliotisdiversicolorReeve)进行了RAPD分析 ,共检测到 2 1 3个位点 ,在群体之间和个体之间都存在差异。利用PopGen32软件计算各群体扩增位点的多态性比例、群体遗传杂和度和群体间的遗传距离 ,多态比例分别为 43.66%、5 3 0 5 % ,2个群体的平均杂合度为 0 .1 5 5 7、0 .1 686。结果表明皱纹盘鲍与杂色鲍的亲缘关系较远。 相似文献
79.
作为海洋高新技术,水声技术日益成为海洋水下探测的主要手段,而且有时是惟一的手段(比如对浑水或对远距离的情况).海底物体搜索、海底救捞、海底探宝、海底“黑烟囱”探测、海底施工以及海洋军事活动(如探测水雷)等多方面都涉及海底小目标(这里的“目标”泛指物体,包括各种人工制造物和自然形成物)探测.对海底小目标探测是一个困难而有意义的课题.高分辨成像声呐在海底小目标探测方面具有良好的应用前景.将高分辨成像声呐应用于海底小目标探测,图像处理是关键.图像分割是图像处理中的主要问题,也是机器视觉领域低层视觉中的主要问题,同时它又是一个经典难题. 相似文献
80.
离子色谱分析在黄土和粉尘研究中的应用 总被引:1,自引:0,他引:1
黄土中存在着大量的碱金属及碱土金属,以往的测试方法多为原子吸收和ICP—MS,离子色谱法在测试黄土样品的碱金属和碱土金属元素含量中应用不多。将黄土地质标准样品进行消解后用离子色谱进行测试,测试效果良好,重复测试的相对标准偏差小于5%,与推荐值的相对误差小于5%,准确度和精密度符舍相关的质量控制要求。本实验方法测试的离子含量都在仪器响应呈线性的最佳测试范围之内,标准曲线经回归后相关系数均达到0.9999。黄土样品的分析结果与粉尘气溶胶样品的离子分析结果对比表明,此方法对于探讨粉尘起源以及沙尘暴天气的研究具有重要意义。 相似文献