南海深海盆表层沉积物氮的地球化学特征与生态学功能   总被引：4，自引：1，他引：4  

郑国侠  宋金明  孙云明  戴纪翠 《海洋学报》2006,28(6):44-52

研究了南海深海盆区域(南沙海槽西南部)表层沉积物中氮的形态、分布及其在生物地球化学循环中的功能.研究表明,表层沉积物中不同形态氮的含量不同.其中,氧化还原转化态的氮(SOEF-N)含量最高,平均为68.3μg/g,占总氮(TN)的7.08%;弱酸转化态氮(WAEF-N)含量最小,仅占总氮(TN)的1.09%.离子交换态(IEF-N),WAEF-N,S OEF-N及TN的地球化学分布特征存在一定相似性:均由海槽东西两侧向中央递增,并在槽底呈高含量分布;SAEF-N(强碱转化态)分布则与该趋势相反.IEF-N,SAEF-N和SOEF-N的分布主要受沉积物中有机碳含量(OC)控制;而WAEF-N则与碳酸盐(CaCO₃)存在显著的负相关关系;TN与OC不具有显著意义的相关,间接说明二者来源的不同.同时,各形态氮的分布还与沉积物粒度类型密切联系.此外,研究区域内由沉积物提供的氮源很大程度上补偿了浮游植物对水体中营养盐的消耗,对维持该海域的初级生产力水平起到一定作用.其中,IEF-N和SOEF-N的释放对浮游植物生长及初级生产力的贡献较为显著.  相似文献   

Growth and Production in Posidonia Oceanica (L.) Delile*     

Jrg A. Ott 《Marine Ecology》1980,1(1):47-64

Abstract. In situ investigations of growth and production in a stand of Posidonia oceanica (L.) DELILE at a depth of 4 m at Ischia (Gulf of Naples) were carried out over two growing seasons. Posidonia starts to grow in August and an average bundle produces ten leaves in increasing time intervals until May. Growth curves for the leaves are given. Maximum leaf standing crop is in May with 1300 g dry weight per m^-2, leaf area index at this time reaches 22 m² m^-2. Leaf net productivity is highest in March with 12 g dry weight per m² per day. Annual leaf production is estimated as 3110 g dry weight per m², “underground” production as 115 g dry weight per m². About half the leaf production is exported from the system. Adaptive strategies of the growth and production pattern are discussed.  相似文献   

南海北部含油气构造上方化探异常研究     

陈汉宗  周蒂  王平 《热带海洋学报》1997,(3)

在南海北部利用地球化学方法作为油气勘探的一种辅助手段。在6个航次中采集了沉积物、底层海水及海面大气样品，测定了近50种化探指标，并采用稳健统计方法进行了数据处理和异常圈定。化探结果在油气藏上方发现了清晰的、具不同指标组合的综合化探异常，与邻近空构造形成鲜明的对照。圈闭顶部的块状异常和圈闭周绿的环状、半环状异常是下伏油气藏的良好指示，而剖面上呈锯齿状、平面上呈线状的异常则与断裂带有关。实践表明，建立已知油气藏上方的化探异常模式及解剖已知空构造上方的地球化学特征对于指导本区或邻区的化探异常评价是十分必要的。  相似文献   

Diel fluctuations in dissolved free amino acids and monosaccharides in Chesapeake Bay dinoflagellate blooms   总被引：1，自引：0，他引：1  

K. G. Sellner  E. W. Nealley 《Marine Chemistry》1997,56(3-4)

The accumulation of phytoplankton biomass in recurring summer dinoflagellate blooms of Chesapeake Bay is accompanied by large pools of dissolved organic matter (DOM). Two fractions of the DOM, free amino acids (DFAA) and monosaccharides (MONO), were measured at 3 h intervals in mixed species dinoflagellate blooms (Katodinium rotundatum, Gymnodinium spp.) and related to productivity, biomass and photoperiod. Peak chlorophyll levels for the three blooms were 28, 65 and 938 μg1⁻¹. In general, DFAA and MONO concentrations increased with increasing biomass of bloom-forming species, reaching 203 and 844 μg1⁻¹. MONO appeared to accumulate during the day while there was no consistent pattern for DFAA. The accumulations of DFAA and MONO in blooms indicate that bloom production might stimulate microheterotrophy, thereby enhancing carbon and nutrient cycling in bloom-impacted regions.  相似文献   

Effects of cold eddy on phytoplankton production and assemblages in Luzon strait bordering the South China Sea   总被引：6，自引：0，他引：6  

Yuh-Ling Lee Chen  Houng-Yung Chen  I. -I. Lin  Ming-An Lee  Jeng Chang 《Journal of Oceanography》2007,63(4):671-683

The biochemical effects of a cold-core eddy that was shed from the Kuroshio Current at the Luzon Strait bordering the South China Sea (SCS) were studied in late spring, a relatively unproductive season in the SCS. The extent of the eddy was determined by time-series images of SeaWiFS ocean color, AVHRR sea surface temperature, and TOPEX/Jason-1 sea surface height anomaly. Nutrient budgets, nitrate-based new production, primary production, and phytoplankton assemblages were compared between the eddy and its surrounding Kuroshio and SCS waters. The enhanced productivity in the eddy was comparable to wintertime productivity in the SCS basin, which is supported by upwelled subsurface nitrate under the prevailing Northeastern Monsoon. There were more Synechococcus, pico-eucaryotes, and diatoms, but less Trichodesmium in the surface water inside the eddy than outside. Prochlorococcus and Richelia intracellularis showed no spatial differences. Water column-integrated primary production (IPP) inside the eddy was 2–3 times that outside the eddy in the SCS (1.09 vs. 0.59 g C m⁻²d⁻¹), as was nitrate-based new production (INP) (0.67 vs. 0.25 g C m⁻²d⁻¹). INP in the eddy was 6 times that in the Kuroshio (0.12 g C m⁻²d⁻¹). IPP and INP in the eddy were higher than the maximum production values ever measured in the SCS basin. Surface chlorophyll a concentration (0.40 mg m⁻³) in the eddy equaled the maximum concentration registered for the SCS basin and was higher than the wintertime average (0.29 ± 0.04 mg m⁻³). INP was 3.5 times as great and IPP was doubled in the eddy compared to the wintertime SCS basin. As cold core eddies form intermittently all year round as the Kuroshio invades the SCS, their effects on phytoplankton productivity and assemblages are likely to have important influences on the biogeochemical cycle of the region.  相似文献   

云南程海近500年来湖泊初始生产力的演化   总被引：14，自引：1，他引：14  

吴敬禄  蒋雪中  夏威岚  潘红玺  尹宇 《海洋地质与第四纪地质》2002,22(2):95-98

程海为富营养化封闭湖泊，通过对程海CH01乳沉积物色素分析，定性恢复了近500a来程海湖泊初始生产力演化过程，结果表明，近500a来程海湖泊初始生产力总体上呈现由低到高的上升趋势，其中1700AD前后，1790AD前后是湖泊初始生产力出现变化的界限，另外，色素含量变化揭示研究时期内存在1750AD前后，1930AD前后二次明显暖波动。  相似文献   

Interannual variability in Nordic seas primary production   总被引：1，自引：0，他引：1  

Skogen  Morten D.; Budgell  W. Paul; Rey  Francisco 《ICES Journal of Marine Science》2007,64(5):889-898

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Elemental geochemical records of seafloor hydrothermal activities in the sediments from the Okinawa Trough     

ZHAI Shikui  YU Zenghui  DU Tongjun 《海洋学报(英文版)》2007,26(4):53-62

The major and minor element contents in the sediment core H9 from the hydrothermal fields of the Okinawa Trough show a sharp change at the depth of 80 cm. The elements enriched in the upper 80 cm core are those enriched in the hydrothermal deposits and in the surface sediments recovered from the hydrothermal fields in the trough, which indicates the input of hydrothermal materials. Comparing with other hydrothermal sediments from Mid-ocean Ridges or the Lau Basin, the degree of the enrichment of elements iron, copper,cobalt, and nickel is relatively low. However, the enrichment of elements manganese, lead, arsenic, antimony and mercury is remarkable. The average contents of these elements in the upper 80 cm core sediments are three to six times those in the lower section, and 3~12 times those in the surface sediments which are not influenced by hydrothermal activities. Hydrothermal activities have contributed significant manganese, lead, arsenic, antimony and mercury to the sediments, and these elements are distinct indicators for the hydrothermal activity in the Okinawa Trough. The significant enrichment of these elements in Core H9 upward from the depth 80 cm indicates the start or the significant enhancing of the hydrothermal activity in this area at about 5 740 aB.P. The average accumulation rate of manganese during this period is about 40 461 μg/(cm2·ka), which is similar to the hydrothermal sediments in the Lau Basin or the East Pacific Rise.  相似文献   

南黄海表层沉积物中氮的区域地球化学特征   总被引：5，自引：0，他引：5  

吕晓霞  宋金明 《海洋科学进展》2003,21(2):174-180

通过分级浸取分离的方法获得了南黄海表层沉积物不同形态的氮，首次探讨其分布的区域性特征：南黄海表层沉积物中各形态氮在不同测线上均呈现出波状分布。B测线的基本上呈现出中部海域高，两边海域低，而西部海域又略高于东部海域的趋势，D和E测线的基本上呈现出西高、东低的趋势，C测线的则呈现出西低、东高的趋势，F测线的变化趋势比较平缓，从整体上看，SOEF—N和TN的分布呈现出西部海区比东部海区低的趋势。受各测线上沉积物种类差异的影响，自北向南各形态氮的变化幅度逐渐减小，其中SOEF-N在各测线上的变化幅度最大，且自北向南降幅最大。受水动力及沉积物粒度的影响，不同形态氮在黄海槽内各站位沉积物中的含量较高。沉积物中各形态氮在不同测线上的分布还表明，陆源输入对南黄海沉积物中氮测线分布有较小的影响，海洋自生氮对南黄海表层沉积物中氮的形态、含量与分布具有重要影响。  相似文献   

基于GIS数据仓库的激光单分子海洋油气化探数据可视化处理          下载免费PDF全文

李谷祺  杨作升  刘?? 展  张?? 勇  初晓璐 《海洋科学》2007,31(2):13-16

采用基于地理信息系统(GIS)的数据仓库技术,以激光单分子海洋油气化探数据处理与评价作为数据仓库主题,实现了激光单分子海洋油气化探数据的可视化处理。将可视化处理分为4个步骤:数据预处理、异常背景分析、异常分析、异常综合评价;使用MAPX、DELPHI等软件研制开发了相应的可视化软件模块。通过对渤海湾盆地某测区实测的甲苯化探数据的处理,验证了所开发技术的实用性。  相似文献