Nutrients, Chlorophyll a and Phytoplankton in the İskenderun Bay (Northeastern Mediterranean)

Abstract. The monthly changes in chlorophyll a , phytoplankton abundance and nutrient concentrations at two stations, one at the inshore and the other at the deep waters of the northern part of İskenderun Bay, were investigated between 1994 – 1995. The vertical distribution of nutrients and phytoplankton biomass were also studied at the deep station. The concentrations of NO₃+NO₂-N, PO₄-P and SiO₄-Si of surface water at both stations were 0.31 – 1.63 µg-at · l^-1, 0.08 – 0.60 µg-at · l^-1 and 0.50 – 2.7 µg-at · l^-1, respectively. The highest concentrations were measured at the inshore station and clear differences were found between the inshore and deep-water stations. Chlorophyll a concentrations ranged from 0.17 to 2.78 µg · l^-1 and the highest value was measured in March. At the inshore station, which was affected by land run-off, phytoplankton abundance reached the highest value (21,308 cells · l^-1) in October 1995, with a marked dominance of Pseudonitzschia pungens (20,200 cells · l^-1). The nutrient and chlorophyll a concentrations at the inshore station were higher than those at the deep station. One reason for this is the land-based nutrient input into the coastal area here. In spite of these effects, the bay is not eutrophicated because of circulation events in the northeastern Mediterranean.     

化合氯对浮游植物对绿素a和光合作用影响的室内研究

化合氯是温排水中主要的化学物质,它的存在会对电厂邻近水域中生活的浮游植物造成一定的影响,运用均匀设计的实验方法研究温度,化合氯浓度,氯处理时间,及这3个因素之间的交互作用,从中筛选出影响叶绿素a含量与光合作用过程的主要因子,结果表明：影响叶绿素a的主要因子是氯处理时间,氯浓度与处理时间之间的交互作用（置信水平为99％）,影响光合作用的主要是氯处理时间,氯浓度,氯处理时间与氯浓度之间的交互作用,以及温度与氯处理时间的交互作用（置换水平为98％）。     

烟威及石岛近海春季水团分析

本文使用1960—1980年春季的水文资料,以温度和盐度作为主要指标,根据聚类分析逼近温盐图解,结合对该海域地理环境特征的分析,对烟台、威海及石岛近海春季的水团结构演变及其和渔场、渔期的关系进行综合分析。结果表明,北黄海及青岛外海的冷水团,以及黄海暖水团的强度与位置的变动,对春季渔期的早迟以及渔场位置的变动,都有很大的影响。     

2000年夏季莱州湾生态环境要素的分布特征

论文依据 2 0 0 0年夏季 8月 2 9日至 9月 2日莱州湾的 1次综合性生态环境调查资料 ,给出了表、中、底 3层的平均温度、盐度、主要营养盐浓度及其比例和叶绿素 a浓度 ,分析了莱州湾的温盐结构、主要营养盐和叶绿素 a的分布特征。由于莱州湾的水深较浅 ,各要素的垂直分布都比较均匀。生态环境要素的水平分布表现为小清河口为高温、低盐、高营养盐和高叶绿素 a浓度区 ,小清河口东测的湾顶区域为高温、高盐、相对低的营养盐和叶绿素 a浓度区。此次观测到的盐度较 1997年以前有明显升高。莱州湾各层平均的 N/ P和 Si/ N分别为 16.73和 1.67,都比 1998～ 1999年渤海中部的值大 ,但 N/ P比 1992 ,1995和 1996年莱州湾的 N/ P明显偏低。叶绿素 a浓度与硅酸盐浓度之间有较好的相关关系 (α=0 .0 1) ,表、中、底 3层叶绿素 a浓度同硅酸盐浓度的线性相关系数分别为 :0 .5 4 ,0 .68和 0 .67     

Use of an optical oxygen sensor to measure dissolved oxygen in seawater

The use of an optical oxygen sensor to measure dissolved oxygen in seawater was investigated. The sensor is based on the dynamic quenching of an oxygen-sensitive fluorochrome embedded in the tip. Dissolved oxygen in seawater samples collected from eight stations at depths ranging from 3000 to 6000 m was analyzed both with the optical sensor and by the Winkler titration method. The two sets of data did not differ significantly. The stability and simplicity of the method and the good agreement of the results with those of the titration method indicate that the sensor would be useful for fieldwork.     

An experimental method for determining the frequency-dependent added mass and added mass moment of inertia for a floating body in heave and pitch motions

Most of the existing relevant materials have been obtained from experiments, in which evaluating the added mass at the resonant frequency corresponding to the peak of a frequency-response curve obtained from the “forced” vibration analysis is the most popular technique. In this paper, a simple experimental method was presented where the “free” vibration responses instead of the “forced” ones were used to determine the values of m_ah and I_ap. The main part of the experimental system is composed of a floating body (model) and a spring–shaft shaker. The “free” vibration of this main part was induced by imposing on it an initial displacement (and/or an initial velocity), and from the time histories of displacements information such as the “damped” natural frequencies, damping ratios, sectional added mass coefficients (C_V and C_P) were obtained. Since the displacements of the spring–shaft shaker are “translational” and those of the floating body due to pitch motions are “angular”, a technique for the transformation between the associated parameters of the two components of the main part was presented.     

软土海岸地区测量控制点标志的设立

分析了软土、湿地、滩涂地区特殊地理环境对测量控制点的影响;主要探讨了此类地区控制点标志的设计、施工。借助于建筑桩基技术和道桥施工方法,首次成功实现了某三角洲湿地滩涂地区统一布网。几年来,结合滩涂湿地测量、海岸防护和滩涂开发工程对部分控制点进行了初步检测,给出了部分检测数据。应用和检测均表明:桩基标石可较好地解决软土、湿地、滩涂地区控制点布设难题,显著提高软土海岸地区测量控制点标志的稳固性,从而延长控制网的可使用期。     

渤海生态动力过程的模型研究 Ⅱ.营养盐以及叶绿素a的季节变化

利用在本系列研究第一部分中所建立的耦合的生物物理模型,模拟了渤海浮游植物生物量和营养盐含量的年度循环特征.模拟结果显示:藻类的春季水华是由经过一冬积累在水体中的营养盐导致,而水华开始的时间在浅水区明显早于深水区,对此深水区水体层化结构的形成可能起着重要作用;另一方面,河载营养盐与悬起的沉积物所释放的营养盐是诱发夏季水华的共同原因.基于模型结果,我们还发现:渤海的浮游植物动力特性就整体而言依然受无机氮限制,但是在莱州湾,磷限制特性表现得非常明显,这主要是由于每年黄河都要携带大量的无机氮进入海水,从而导致莱州湾营养盐的氮磷比已远远超过16.     

Water mass formation variability in the intermediate layer of the east sea

Long-term variability in the intermediate layer of the eastern Japan Basin has been investigated to understand the variability of water mass formation in the East Sea. The simultaneous decrease of temperature at shallower depths and oxygen increasing at deeper depths in the intermediate layer took place in the late 1960’s and the mid-1980’s. Records of winter sea surface temperatures and air temperatures showed that there were cold winters that persisted for several years during those periods. Therefore, it was assumed that a large amount of newly-formed water was supplied to the intermediate layer during those cold winters. Close analysis suggests that the formation of the Upper Portion of Proper Water occurred in the late 1960’s and the Central Water in the mid-1980’s.     

WATER MASS FORMATION IN THE SOUTH INDIAN OCEAN BY AIR-SEA FLUXES

1Introduction　TheIndianCentralWater (ICW) ,formedandsubductedintheSubtropicalConvergenceintheSouthIndianOcean ,occupiesasignificantportionofthethermoclineintheIndianOcean[1,2 ]　 (Fig .1 ) .TheSubantarcticModeWater(SAMW)isformedinthe 2 6.5-2 7.1σθrangenorthoftheSub antarcticFront—thesouthernboundaryofthesubtropicalgyres[3]　 .InthesoutheastIndianO cean ,theSAMWisthethickest,ventilatedasathicklayerofhighoxygenextendingtothetropicalIndianOcean[4 ,5 ]　 .　Watermasstransformation…