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851.
于2006~2007年之间采集浙江省温州南麂列岛海域水样.研究了硅藻和甲藻群落变化与环境因子的关系.硅藻集群的高峰区主要集中在水温较高的夏季,调查期间共发生赤潮2起,分别出现在2006年8月和10月.甲藻赤潮仅在春季发生.优势种类为原甲藻种类.硅藻赤潮对N的消耗较大,甲藻赤潮对P的消耗较大.南麂海域合适的温度、盐度、丰富的N、P营养盐以及营养盐的及时补充是该海域浮游植物丰度较高和赤潮频繁发生的主要原因.  相似文献   
852.
春季黄、东海表层水中的溶解无机碳   总被引:2,自引:0,他引:2  
根据2009年5月在黄、东海海域获得的表层海水中溶解无机碳(DIC)和总碱度(TA)的数据,结合现场生物、化学和水文等参数,探讨了该海域DIC的分布特征、组成情况及其影响因素.结果表明,黄、东海表层海水DIC和TA的变化范围分别为1 918.8~2 196.1 μmol/L和2 127.0 ~2 420.7μmol/L...  相似文献   
853.
Concentrations and areal distribution of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn were determined in the surficial sea bottom sediments along the coastal areas of Istanbul at the southern exit of the Bosphorus Strait, ?stanbul, Turkey. The pollution status of shelf sediments was evaluated by employing pollution indicators (enrichment factors, geo-accumulation, and ecological risk indexes) and sediment quality guidelines (threshold effect level/probable effect level, effect range median (ERM)/effect range low). The results demonstrated that Cd, Cr, Zn, Cu, and Pb were enriched minor to moderate. The net sediment transport patterns show terrestrial inputs in front of the short streams. Another polluted region is at the western margin of the southern Bosphorus exit, where sediment transport is mainly controlled by the secondary currents driven by the Bosphorus jet, and depending on a sand ridge extending offshore. Based on the sediment quality guidelines, Cu, Pb, As, and Cr were likely the most dangerous chemicals to pose environmental risk, and may show toxic biological results. The areal distribution of ecotoxicological index (m-ERM-Q) suggested that 20% of the sediment sample sites fall in the medium–high priority zone and scattered at some specific areas along the coast.  相似文献   
854.
The long-term population dynamics of the white-eyed pochard (Aythya nyroca) in the eastern Sea of Azov region was analyzed. It was found that the local population of this species tends to decrease in size. Clutch size, egg size, reproductive behavior, intraspecific clutches, embryonic mortality, and hatching success in this population were studied. The contents of PCDD and PCDF in the eggs of waterfowl were estimated. The eggs of white-eyed pochard, compared to other waterfowl, proved to contain abnormally high concentrations of xenobiotics. Possible causes of A. nyrocapopulation decline, including the impact of superecotoxicants, are discussed.  相似文献   
855.
渤海越冬场渔业生物资源量和群落结构的动态特征   总被引:15,自引:0,他引:15  
根据1983、1993和1999年冬季在渤海越冬场拖网试捕采集的渔获量资料,分析研究了渤海渔业生物地方种群的种类组成、生物量指数和优势种群的年间变化。资源量呈逐年大幅度减少之势,平均网获量分别为115kg/h、35kg/h和07kg/h,平均网获尾数则为669尾/h、145尾/h和37尾/h;群落结构和优势种发生了明显的变化,1983~1993年的优势种群梅童和孔鳐等经济底层鱼类为安氏新银鱼所替代。捕捞过度是经济种群资源量剧减的主要原因,强化渔政管理,开展经济种群的种苗放流是保护、恢复和增殖渔业资源的主要措施和途径。  相似文献   
856.
为了研究X80、EH36和45#钢在东海海域42个站位的初期腐蚀速率.通过动电位极化曲线法获取出海实测的X80、45#和EH36钢2019年9月在东海42个站位的初期腐蚀速率数据,并以地统计学方法对数据进行分析,探索研究区内3种钢材初期腐蚀速率的空间分布及其变异特征,绘制初期腐蚀速率预测图.对于每一种钢材初期腐蚀速率的空间分布,45#钢在西南部高,东北部低;EH36钢在东北部高,西南部低;而X80钢靠近长江口海域低,其他海域高.X80、45#、EH36钢在东海的平均初期腐蚀速率分别为0.42、0.49、0.17 mm/a,并且3种钢材在东海初期腐蚀速率分布的空间变异特征明显,空间自相关性强,X80、45#、EH36钢的块金值分别为0.0148、0.0044、0.0017,变程为1000~2000 km.  相似文献   
857.
The increase in the number of tourists visiting a coast is desired by most of the countries for economic reasons. However, this increase in tourism may cause pollution of the sea. This can be only avoided by proper planning and by predicting the carrying capacity of the coast in terms of sea pollution. This is especially important for developing countries where part of the wastewater is discharged without any treatment into the sea.In the present study the beaches were classified according to their use — and consequently the amount of waste discharged into the sea — into four groups: (1) coasts that are used only for swimming and recreational purposes; (2) coasts used simultaneously for dwelling, swimming, and recreational purposes; (3) coasts along which only dwellings exist; and (4) natural and man-made harbors, i.e., coasts used as shelters. During the survey,40,320 observations were made between December 1985 and February 1988 to determine the effect of the number of tourists on seawater quality. The results obtained were analyzed by a multilinear regression program to obtain an empirical equation giving the extent of the sea pollution in terms of coliform concentration as a function of population density and some other environmental factors.The equations derived in this study enable the determination of the carrying capacity of a beach in terms of pollution as well as the expected degree of pollution corresponding to a given population density. Furthermore, it allows the prediction of the extra carrying capacity that can be obtained by improving the waste-disposal conditions.  相似文献   
858.
859.
Sea surface colour data, derived from the Coastal Zone Colour Scanner (CZCS) archive, have been used to assess the space/time variability of coastal plumes and run-off in the Mediterranean Sea. A time series of 2645 scenes, collected by the CZCS from 1979 to 1985, was processed to apply sensor calibration algorithms, correct for atmospheric contamination, and derive chlorophyll-like pigment concentration. Individual images, remapped on a 1-km2 pixel grid, were generated for each available day, and then mean values calculated pixel by pixel to form monthly, seasonal and annual composites. The results obtained must be taken with caution, due to the CZCS limitations in the quantitative assessment of bio-optical pigments when high concentrations of dissolved organics or suspended sediments are present, e.g. along littorals or within plumes. Marked differences appear in the distribution of water constituents between coastal zones and open sea, northern and southern near-coastal areas, western and eastern sub-basins. The oligotrophic character of the basin contrasts with areas of high concentration related to river plumes—Ebro (Ebre), Po, Rhone, Nile—, coastal run-off patterns, and persistent mesoscale features (e.g. coastal filaments and eddies). Seasonal variability appears to be high, with higher concentrations occurring over most of the basin in the cold season, when climatic conditions are favourable to coastal run-off and vertical mixing. Atmospheric forcing (wind and rainfall over continental margins) could play an important role in establishing the observed space/time distribution of water constituents. The impact of continental interactions (fluvial and coastal run-off), or that of exchanges between coastal zone and open sea, could have paramount influence on the biogeochemical fluxes in the entire basin.  相似文献   
860.
北黄海与渤海沉积物中磷形态的分布特征   总被引:7,自引:0,他引:7  
对1998年9月和1999年5月渤海航次和1999年8月北黄海航次所采集的柱状沉积物和表层沉积物样品进行了P形态的六步连续提取分析,分析了各种形态P在表层及垂直方向上的分布特征。并通过对沉积物充空气和N2条件下培养前后各步形态P的测定,认识各步形态P培养前后的变化以及不同的氧化还原环境对各步形态P的影响。结果表明:从渤海到并黄海总P的含量逐步降低。碎屑磷灰石的含量在六步中含量最高,约占50%左右,其次是非活性有机磷,约占20%,其他几步含量较小;充N2培养沉积物样品中碎屑磷灰石的含量要比充空气的低,其他形态的P较充空气培养的略高或相关不大。  相似文献   
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