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1.
台湾东部黑潮区海源碳的沉积物记录与近千年来生产力与气候变化的反演 总被引：1，自引：0，他引：1
本文基于对台湾以东黑潮主流区沉积物的粒度和定年，通过解析沉积物总有机碳及其同位素组成获取海源碳变化特征，首次报道了该海区近千年来的初级生产力与气候变化反演结果。研究显示，台湾以东黑潮主流区近千年来的平均沉积速率为34.44 cm/ka，沉积环境较为稳定。另外，台湾以东黑潮主流区沉积物中的总有机碳和总氮含量主要受台湾东部河流输入、海洋初级生产力的沉降过程、成岩作用和粒度效应影响。对沉积物海源碳的定量估算表明，近千年来台湾以东黑潮主流区沉积物中40.02%~73.88%的有机质为海源输入，陆源输送次之。同时，近千年来台湾以东黑潮主流区沉积物记录较好地反映了中世纪暖期、小冰期和现代暖期3个气候变化阶段。1150-1420年期间，沉积物中总有机碳、总氮和海源碳含量缓慢升高，较高的表层海水温度有利于海洋初级生产力水平的升高。1500-1840年期间，较低的表层海水温度和亚洲大陆风尘输送水平使得海洋初级生产力较低，同时台湾地区小冰期较高的降水量有利于台湾东部河流向海输送，增强的水动力条件可能会加强海底沉积物的东移，从而导致该区域沉积物中总有机碳含量的增加。进入现代暖期以来研究区的海水温度逐渐增暖，而东亚季风强度和降水量却表现出波动的年际变化特征，并体现在研究区1930-1950年和1970年期间沉积物的中值粒径、总有机碳和总氮含量的快速波动。 相似文献
2.
采用稀释涂板法研究了南麂岛海域沉积物中海洋放线菌的分离技术,分析了真空干燥处理、热处理、海水浓度、培养基种类等因素对分离效果的影响;首次将羧甲基纤维素钠(CMC)溶液应用于海洋沉积物样品的预处理,探讨了不同浓度的CMC对海洋沉积物样品中放线菌分离结果的影响。结果表明:海洋沉积物经干燥处理、50℃热处理20 min均能有效地减少细菌数量,利于海洋沉积物中放线菌的分离;60%的海水配制的培养基对海洋放线菌的分离效果优于纯海水所配培养基,并且培养基中添加海泥浸出液能有效地增加海洋放线菌的出菌率;以质量浓度为2 g/L的CMC为分散剂时,不仅能良好地分散沉积物样品中的放线菌孢子,而且能明显地增加海洋放线菌的检出量及稀有放线菌的数量。 相似文献
3.
由中国科学院海洋研究所青年学者来金明同志独立完成的35万字的《中国海沉积物一海水界面化学》专著，将于1997年1月由海洋出版社出版发行。该专著是中国第一部海洋界面化学专著，也是世界上第一部有关中国海沉积物一海水界面化学专著。作为学科交叉新的生长点，海洋沉积物一海水界面化学的研究在国际也不过刀多年的历史，在我国仅有10多年。由于海洋沉积物一海水界面过程参与了海洋中许多复杂的生物地球化学过程，所以已成为当今海洋学研究的热点之一。《中国海沉积物一海水界面化学》是著者及其研究组10年来把当今海洋学研究的前沿领域，… 相似文献
4.
海洋沉积物含水率对部分碱金属及碱土金属元素含量的影响及意义 总被引：1，自引：0，他引：1
利用电感耦合等离子体光谱仪(ICP-AES)对海洋表层沉积物及上覆海水、海洋沉积物国家标准物质、陆地的水系沉积物及土壤国家标准物质进行检测以对比海洋沉积物含水率对部分碱金属及碱土金属元素分析结果所造成的影响。结果显示海洋沉积物含水率对钠离子影响最大,往往有超过50%的钠离子来自其中所含海水的贡献,而海洋沉积物含水率对钾、钙、镁的影响则较为微弱。因此,研究海洋沉积物化学组分时有必要考虑其所含海水对钠含量的贡献,以期达到不同海洋沉积物化学组分的可比性。 相似文献
5.
元素分析仪快速测定海洋沉积物TOC和TN的条件优化 总被引：4，自引：0，他引：4
报道了在优化样品前处理、燃烧温度、最小加氧量和最佳称样量的基础上,综合构建优化了直接固体进样varioMACRO cube元素分析仪同时测定海洋沉积物样品中总有机碳(TOC)和总氮(TN)的条件,即准确称取20~30 mg沉积物样品用1 mol/L盐酸除去无机碳后,直接进样在燃烧管温度960℃,次级燃烧管温度830℃,还原管温度900℃,氦气压力0.12 MPa,流量600 mL/min,氧气压力0.20 MPa,加氧量22.5 mL仪器条件下,用标准曲线法峰面积获取TOC和TN浓度。结果表明,海洋沉积物中TOC和TN测定的检出限分别为0.0508%和0.0146%,回收率分别为97.7%~100.9%和97.2%~101.1%,对4个实际外海沉积物样测定总有机碳和总氮结果的相对标准偏差(RSD)为0.83%~3.06%和1.33%~3.49%(n=12)。该方法操作简便快速、灵敏度高,具有较好的精密度和准确度,可准确可靠地用于海洋沉积物中总有机碳和总氮含量的测定。 相似文献
6.
对南黄海和东海北部462个表层沉积物样品进行了有机碳、总氮及粒度测试,以趋探讨表层沉积物有机质的分布规
律及来源。结果表明：南黄海及东海北部陆架区沉积有机碳质量分数分布范围为0.11 豫耀0.82 豫,均值为0.44 豫;总氮质量
分数分布范围为0.01 豫耀0.11 豫,均值为0.06 豫。有机碳及总氮质量分数平面分布特征相似,泥质沉积区质量分数较高,砂
质沉积区较低,最高值位于杭州湾外部。其分布特征明显遵从粒度效应,随着粒度变粗,有机碳、总氮质量分数减小,其中
在粒度>4准的细粒沉积物中,粒度处于6原11准的细粒沉积物更为富集有机碳。沉积物C/N比值显示,南黄海及东海北部大部
分区域沉积有机质为陆地和海洋混合来源,仅在123.5毅E以东、31毅N以南东海中陆架小部分区域为海洋自生来源。 相似文献
7.
任保卫 《海洋与海岸带开发》2014,(4):95-99
文章根据2012年8月对福建罗源湾海域的环境质量调查结果,结合海洋功能区划对海洋环境质量现状进行了评价与分析,并综合分析了海水中富营养化程度,沉积物中重金属的富集程度与生态风险效应。结果表明:该海域水质中除活性磷酸盐、无机氮和石油类存在超标外,其他环境因子均符合功能区划要求的海水水质标准。沉积物中除滴滴涕外,其他因子均符合海洋沉积物标准。20%的站位富营养化指数大于1,该海区的富营养化程度较低。沉积物中铅的富集程度相对较大,沉积物重金属的潜在生态危害轻微。 相似文献
8.
海洋里面到底有多少古菌?古菌不仅在海水中从表层到深部都有大量存在,而且在海洋沉积物及深部也广泛存在,并且海水中的浮游古菌和沉积物中的底栖古菌有着本质的差别,在此只针对海水中的浮游古菌进行介绍和讨论。浮游古菌是海洋生物量最多的微型生物之一。目前,从太平洋和大西洋,从水体表层到深部以及海底沉积物中都检测到大量古菌的存在。 相似文献
9.
海洋沉积物/颗粒物在生源要素循环中的作用及生态学功能 总被引：2，自引：1，他引：1
海洋沉积物/颗粒物是生源要素循环过程中的关键源与汇，沉积物/颗粒物一方面是海水生源要素的主要归宿，生源要素从溶解态经复杂的生物-化学过程转变为颗粒态，颗粒物质再沉降形成沉积物，另一方面，海洋沉积物/颗粒物经过微生物-浮游动物-底栖生物作用分解形成溶解态的生源要素，并释放到海水中再次被浮游植物利用，进入下一轮循环，所以，海洋沉积物/颗粒物具有异常重要的生态学功能。浮游植物是海水溶解态生源要素的利用者和海源颗粒态生源要素的初始形成者，浮游动物通过摄食浮游植物或其他有机颗粒物可释放出溶解态生源要素或形成更大的颗粒物，颗粒物沉降后形成的沉积物又通过底栖生物摄食-扰动-破碎等过程将颗粒生源要素释放进入水体参与再循环。生态系统不同类群的生物在颗粒生源要素的释放-沉降中所起的作用不同而又相互关联，其中浮游动物-底栖生物的摄食与代谢、微生物参与的分解过程起着非常重要的作用。所以，海洋沉积物/颗粒物生态学功能研究作为支撑海洋环境和资源的持续利用的科学基础，已成为海洋科学的前沿领域，必将获得跨越发展。 相似文献
10.
为研究七连屿海洋环境质量状况,于2017年8月在七连屿海域布设20个采样站位,共采集到22个表层海水样品及6个表层沉积物样品,通过原子吸收分光光度计及原子荧光分光光度计测定海水及沉积物中重金属(Cu、Pb、Zn、Cd、Cr、As、Hg)的含量,采用单因子评价法、综合污染指数法及相关性分析对水质重金属污染程度进行研究,并采用单因子评价法及Hankanson潜在生态风险指数法分别对沉积物质量及沉积物中重金属潜在生态风险进行评价。结果表明,2017年七连屿海域表层海水重金属含量CZn>CPb>CAs>CCr>CCu>CCd>CHg,部分站位海水铅含量超一类海水水质标准,但是综合污染指数小于1,该调查海域表层海水属于清洁型;海水中Zn-As、Cr-Cd含量之间存在显著负相关关系,此两组元素存在明显异源性;该调查海域表层沉积物重金属含量均符合第一类海洋沉积物质量标准,沉积物重金属对海洋生态系统仅存在轻微生态风险。 相似文献
11.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
12.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
13.
The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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15.
《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
16.
The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance. 相似文献
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18.
Rahul Sharma 《Marine Georesources & Geotechnology》2000,18(3):237-250
Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in predisturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions. 相似文献
19.
Vance P. Vicente 《Marine Ecology》1989,10(2):179-191
Abstract. Long-term changes in the distributional patterns of commercial sponges ( Spongia spp. and Hippospongia spp.) within the West Indian Region indicates that: 1) commercial sponges had a widespread distribution throughout the whole West Indian Region and were ubiquitous in very shallow water until about the first half of the present century; 2) they were fished commercially not only in the traditional northern Caribbean sites (Florida, Gulf of Mexico, Bahamas) but also in the Greater ( e. g. , Hispaniola, Jamaica) and Lesser Antilles; and 3) they became extinct throughout most of the Lesser Antilles ( e. g. , Puerto Rico, Vieques, St. Thomas) sometime during the first half of this century. Mortalities of spongiids within the Antilles were found to differ from other marine mortalities in that: 1) species disappeared from a large region; 2) species vanished from different habitats and depths; and 3) natural populations never recovered. Species richness patterns suggest that commercial sponge genera ( Spongia and Hippospongia ) evolved under slightly cooler elimatic conditions than those found at present, and that these extinctions occurred as a direct or indirect effect of positive thermal anomalies in sea surface and atmospheric temperatures between 1900–1950. The concept that species diversity is stable on a regional scale is questioned. 相似文献
20.
The behaviour of an axially pre-loaded cylindrical member of an offshore structure, hit by a supply ship, has been investigated. The effects of axial pre-loading on the dynamic properties of members, the extent of damage and propagation of dynamic instability in the tubular members have also been investigated. Numerical models have been validated using available experimental data from the literature although these are mostly static with no pre-loading. Axial pre-loading was found to change the dynamic characteristics of some cylindrical members quite dramatically while it had no significant effect on others. The study examined whether there was any change in the behaviour between local and global modes when the loading was dynamic rather than static. The effect of damping on the dynamic instability of axially pre-loaded tubes under lateral dynamic loads was also studied. It was observed that for some geometries the quasi-static response can be used to define the boundary between bounded and unbounded dynamic responses. The main contribution of this study, compared with previous investigations reported in the literature, is that both pre-loading and dynamic effects have been included. 相似文献