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透明胞外聚合颗粒物（TEP）是凝聚网的重要组成部分甚至核心，在微尺度范围上形成了水环境结构的重要梯度，对于元素地球化学生物循环、碳沉降以及食物网有着举足轻重的作用。本文研究了东海典型断面PN透明胞外聚合颗粒物的分布特征及来源。结果表明:东海典型断面PN透明胞外聚合颗粒物含量介于28~376 μg Xeq./L之间，平均值为（115±67）μg Xeq./L；呈现出明显的夏季 > 冬季 > 秋季 > 春季的季节变化特征以及近岸 > 外海和底层 > 表层的分布趋势。通过对比透明胞外聚合颗粒物分布趋势和硅藻、甲藻分布趋势以及统计分析得出，东海典型断面PN透明胞外聚合颗粒物主要来源于硅藻，甲藻贡献不大；而外海TEP的来源可能主要由超微型浮游植物贡献。 相似文献
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透明胞外聚合颗粒物(TEP)在海洋微食物网和海洋碳循环中发挥着重要作用。本文针对夏季闽东沿海TEP的分布特征及影响因素进行研究。结果表明,闽东沿海TEP含量(以黄原胶为标准物质计算,后同)范围为25.2～935.5 μg/L,平均值为(201.8±177.9) μg/L。整体而言,TEP的分布表现为近岸高、远岸低,表层TEP含量相对于底层要低。相关性分析显示,研究海域TEP含量与浊度和营养盐(硅酸盐、磷酸盐、硝酸盐、亚硝酸盐和铵盐)浓度呈正相关,与pH、溶解氧浓度和小型浮游生物量呈负相关。分级叶绿素a结果显示,相对于其他尺寸浮游植物,调查海域小型浮游生物可能对TEP含量的贡献最大。相比于开阔大洋中TEP主控因素为浮游植物而言,夏季闽东海域TEP主要由浮游植物在衰退阶段产生,其分布主要受颗粒物再悬浮作用影响。该结果不仅进一步阐明了近岸海域与开阔大洋TEP影响因素的区别,并且对我国近海海域不同区域TEP分布研究空白进行了补充。 相似文献
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北白令海透明胞外聚合颗粒物的含量与来源 总被引：2，自引：1，他引：1
透明胞外聚合颗粒物(TEP)是海水中大量存在的黏性颗粒物质,它对于海洋颗粒物的聚集、有机碳的埋藏、食物网物质的传递、痕量金属的清除与迁出等均起着重要作用。本研究开展了夏季北白令海陆架、陆坡和海盆区透明胞外聚合颗粒物含量和分布的研究。结果表明,北白令海TEP含量介于34~628 mg/m3(Xeq)之间,其中陆架、陆坡和海盆区TEP的平均含量分别为240, 145和83 mg/m3(Xeq),整体呈现由陆架向外海降低的趋势。在陆坡和海盆区,TEP含量随着深度的增加而降低,但在陆架近底层水中,观察到TEP高含量的特征,与近底层水高的TSM, POC相对应。TEP与荧光强度、TSM、POC等的关系分析显示,研究海域TEP存在两个来源,其一为海洋上层水体的浮游生物,其主要贡献于陆架上层、陆坡和海盆水体;其二为陆架沉积物的底栖生物,其通过沉积物再悬浮贡献于陆架近底层水。 相似文献
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广西北部湾近岸海域虽常年为磷限制状态，但球形棕囊藻（Phaeocystis Globosa）赤潮灾害频繁发生。球形棕囊藻暴发时主要以囊体形式存在，赤潮衰退后，囊体破裂产生大量的透明胞外聚合颗粒物（Transparent Exopolymer Particles,TEP），在海洋动力作用下形成高碳、高黏性泡沫，影响渔业和核电取水安全。本文通过设置氮磷比为32∶1和64∶1的半连续培养实验，探讨磷限制对球形棕囊藻的生长，以及透明胞外聚合颗粒物产量的影响。结果表明：在氮磷比为32∶1和64∶1的磷限制条件下，球形棕囊藻的细胞密度、叶绿素a浓度、囊体密度及囊体表面细胞数，在培养的后半期都受到了抑制。与控制组相比，两个磷限制的处理组在囊体直径上并没有表现出显著的差异（显著性水平p> 0.05）。在氮磷比为32∶1的条件下，球形棕囊藻的TEP生产量与控制组相比没有显著差异（p> 0.05），在氮磷比为64∶1的条件下，TEP的生产量显著降低（p <0.05），磷限制程度的加剧对球形棕囊藻细胞分泌TEP产生影响。研究结果为进一步研究环境胁迫下球形棕囊藻TEP形成机制提供了依据。 相似文献
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本文研究夏季珠江口透明胞外聚合颗粒物(TEP)含量以及分布特征.结果表明,珠江口TEP含量(以黄原胶物质的量计算,下同)范围在85.0-1234.9μg·L-1之间,平均值为690.9μg·L-1.表层和底层TEP均值分别为562.3μg·L-1和778.2μg·L-1,大部分站位表层TEP含量略低于底层.TEP在表层分布自上游至下游逐渐递增,而向外海以及人海口东西两侧延伸逐渐降低.内河口为底层TEP含量高值区,虎门附近S3站TEP含量最高.TEP与不同粒径浮游植物叶绿素a的相关性分析表明微型浮游植物(粒径3-20μm)可能对珠江口TEP贡献较大.珠江口TEP/Ch1a比值与活性硅酸盐、硝酸盐、铵盐和总磷浓度呈现负相关性;表层TEP/Ch1a比值与盐度呈现正相关性,这表明盐度和营养盐可能是影响TEP含量的重要因素. 相似文献
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《海洋地质前沿》2015,(11)
一直以来,对于测定从海洋表层到深层整个全水柱的颗粒物输出通量都是一个很大的挑战。放射性元素~(234)Th因其合适的半衰期(t_(1/2)=24.1d)和超强的颗粒物活性而被广泛应用于示踪颗粒物的循环以及和生物有关的海洋过程,并且~(234)Th/~(238)U不平衡法因其采样简单且能得到高分辨率的垂向和水平向数据而具有更远的发展前景。主要介绍了~(234)Th/~(238)U不平衡法的原理、发展历史、采样和分析方法及其在海洋颗粒物循环过程和其他海洋学研究中的应用、存在的问题和发展前景,并重点探究其对于研究颗粒物有机物再矿化过程和受控机制以及深海碳循环的可能。 相似文献
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透明胞外聚合颗粒物（TEP）具有高黏性、低密度和高碳氮比等特性,在颗粒有机物的聚集以及食物网循环中发挥着重要作用。为了解近岸海域TEP的分布动力学规律与机制,本文对温州近海夏秋季节水体中透明胞外聚合颗粒物的分布进行调查,并结合多项环境要素的主成分分析与相关性分析,探究了浙江南部近岸海域TEP分布的影响因素。结果显示,温州近海TEP秋季平均含量明显高于夏季,夏季TEP分布变化主要受陆地径流（瓯江）作用影响,而秋季主要受闽浙沿岸流影响。受沿岸流影响,秋季TEP的主要来源可能是其他海域以及底层颗粒物再悬浮。此外,由浮游植物释放的TEP对夏季的POC贡献最大,而秋季外源性TEP对POC的贡献较夏季有所升高。 相似文献
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南海表面浮力通量、水型变性及南海"暖水"的消长分析 总被引：1，自引：0，他引：1
利用英国南安普敦海洋中心(SOC)海-气界面的热量和淡水通量资料以及世界大洋图集(WOA01)的海面温度和盐度资料计算了南海表面各月的有效浮力通量及水型变性矢量场,分析了南海表层暖水形成和发展的季节性特征。研究结果表明,南海表层暖水的发展、维持以及消亡在很大程度上受到海洋表层浮力通量的影响;此外,南海上层水体密度的垂直结构和变化也深受表面浮力通量和表层水型变性的影响。在中、北部,南海的垂向结构季节性变化较为明显,其中冬季表层水体的下沉强度最大,深度最深,而夏季表层水体却无下沉趋势。 相似文献
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根据中国SOLAS计划2006年4月航次出海调查所得数据，系统地研究了春季黄海表面海水溶解无机碳（DIC）的分布规律，同时，与2005年3月、5月两个航次的DIC调查结果进行了对比。结果表明：（1）DIC浓度由近岸向外海逐渐降低；（2）DIC浓度在海水微表层中明显大于次表层和表层，呈现富集现象；（3）由于海水微表层的多层模型特征和海水微表层中Gibbs吸附异常的共同作用，使DIC含量在海水微表层、次表层和表层中变化趋势呈现非线性；（4）在连续站的周日变化研究中发现，DIC浓度在02：00～03：00时间范围内出现最大值，在13：00～15：00时间范围内出现最小值，呈“单峰”分布规律；（5）对比2005年研究结果，发现黄海春季表面海水中的DIC浓度在3，4，5月份依次降低；（6）DIC与温度和盐度均呈较明显的负相关性。 相似文献
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《Deep Sea Research Part I: Oceanographic Research Papers》2001,48(1):1-48
Reduced ice extent within coastal regions of the Southern Ocean may lead to deeper surface mixed layers (SML), as prevail in offshore areas. A future decline of ice melt-induced stability of the water column may be associated with a shift in dominant food webs, from larger, sun-adapted diatoms grazed by euphausiids to smaller, shade-adapted flagellates consumed by salps. A basically one-dimensional numerical model of three dominant groups of the Antarctic phytoplankton community (diatoms, cryptophytes, and colonial prymnesiophytes) and four types of herbivore (protozoans, salps, copepods, and euphausiids) is used to explore the seasonal importance of both light limitation and grazing pressure on the amount of annual carbon sequestration and larval krill survival within contrasting oceanic and neritic waters, where respective validation data have been gathered during austral spring by the European JGOFS and RACER programs. With imposition of moderate and large grazing stresses, thought to be typical of offshore waters, we were able to replicate the European JGOFS 1992 observations of light penetration, phytoplankton biomass, primary production, pCO2, bacterial biomass, labile DOC, ammonium, and total particle effluxes at 100 m within the deep SML of our model. The fidelity of such a large set of simulated state variables suggests that multiple limiting factors are indeed operating on different components of the oceanic phytoplankton community — selective grazing losses on the flagellates, but light limitation of diatoms. Release of protozoan grazing pressure in our model instead leads to unobserved spring blooms of cryptophytes, found only in laboratory enclosures. On an annual basis, weak sequestration of atmospheric CO2 is simulated in a habitat typical of the Polar Front, while evasion of carbon dioxide occurs under biophysical conditions of the Antarctic Circumpolar Current. Stratification in shallow SML and the same absolute grazing demands by krill and copepods allows sun-adapted diatoms of our model to bloom at the expense of shade-adapted cryptophytes and prymnesiophytes, eaten by salps and protozoans. We were also able to replicate RACER-I observations of the same suite of variables in 1986–1987, as well as the observed 10-fold range of detrital fluxes caught by other sediment trap deployments during 1980 and 1983 along the Antarctic Peninsula. In western Bransfield Strait, coastal waters are a strong sink for atmospheric CO2 within parcels of Bellingshausen Sea origin, but not perhaps in those from the Weddell Sea, which resemble the oceanic regime of deep SML. We conclude that even in shallow neritic SML, some protozoan rivals of larval krill must still crop flagellates to ensure sufficient abundance of diatom food for both euphausiid survival and possible clogging of the mucous nets of other salp rivals. 相似文献
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E. Ortega-Retuerta I. Reche E. Pulido-Villena S. Agustí C.M. Duarte 《Marine Chemistry》2009,115(1-2):59-65
Transparent exopolymer particles (TEP) are formed by the assembly of dissolved precursors, mainly mono and polysaccharides (DMCHO and DPCHO) that are released by microorganisms. Although TEP formation plays a significant role in carbon export to deep waters and can affect gas exchange at the sea surface, simultaneous measurements of TEP and their precursors in natural waters have been scantly reported. In this study, we described the spatial (vertical and regional) distribution of TEP, DMCHO and DPCHO in a region located around the Antarctic Peninsula, assessed their contribution to the total organic carbon pool, and explored their relationships with phytoplankton (with chlorophyll a (chl a) as a proxy) and bacteria. TEP concentration ranged from undetectable values to 48.9 µg XG eq L− 1 with a mean value of 15.4 µg XG eq L− 1 (11.6 µg TEP-C L− 1). DMCHO and DPCHO showed average values of 4.3 µmol C L− 1 and 8.6 µmol C L− 1, respectively. We did not find simple relationships between the concentrations of TEP and dissolved carbohydrates, but a negative correlation between DMCHO and DPCHO was observed. Chl a was the best regressor of TEP concentration in waters within the upper mixed layer, while bacterial production was the best regressor of TEP concentration below the mixed layer, underlining the direct link between these particles and bacterial activity in deep waters. 相似文献
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Index species of zooplankton of the Oyashio water are found in and beneath the salinity minimum layer in Sagami Bay. In order to clarify the intrusion path of the intermediate Oyashio Water (or the water of the Mixed Water Region), the oceanographic conditions off the Boso Peninsula are studied by using available hydrographic data obtained mainly by Japan Meteorological Agency. The cross-sectional salinity distribution along KJ line which extends southeastward from off the tip of the peninsula always indicates the existence of a low salinity patch just off the coast in the salinity minimum layer. This water is well separated from the offshore low salinity water which is considered as the water in the western margin of the so-called North Pacific Intermediate Water. We refer to the former water as the coastal salinity-minimum-layer (SML) water and to the latter as the offshore SML water. The coastal SML water is usually bounded by the current zone of the Kuroshio. The existence of the coastal SML water seems to indicate the possible pathway of the intermediate Oyashio water along the Boso Peninsula into Sagami Bay. The detailed water type analysis is made in T-S plane, S-st plane, and O2-st plane. There is no significant difference in distribution ranges of the water types between the coastal SML water and the offshore SML water. However, the water types of the coastal SML water is not uniformly distributed, and the water can be classified into two groups: group A with relatively high oxygen content and relatively low salinity value and group B with relatively low oxygen content and relatively high salinity value. Group A is thought to be associated with strong event-like intrusions, the details of which will be discussed in Part II. 相似文献
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Transparent exopolymer particles (TEP) in aquatic environments 总被引：7，自引：0，他引：7
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基于室内物理模拟实验, 对长江沉积物进行淡水和海水环境下沉积物搬运过程碳释放通量实验模拟。结果表明, 模拟实验初期, 淡水和海水均为大气CO2的源, 但淡水CO2释放通量略高于海水;淡水、海水两种环境下, CH4释放通量均较小, 为弱释放-弱吸收过程。对两种环境下碳通量对比研究发现,Eh 值可能是造成淡水和海水环境下CO2通量差别的主要原因, 而pH 值可能对CO2通量差别的影响较小。两种环境下温室气体通量差别的具体原因仍需进一步研究。通过模拟对比试验, 旨在为系统地认识长江流域水库的温室效应与减排提供科学依据, 为我国清洁水电能源发展提供理论参考。 相似文献
17.
A closed dynamic compartment model of the global carbon cycle and its modifications with a small number of external parameters, which are constructed on the basis of data on the current and preindustrial carbon fluxes and reserves in reservoirs, are studied. The first possible controlling parameter is the amount of anthropogenic CO2 emission into the atmosphere. Closure in substance allows a decrease in the dimensionality of dynamic models and yields another variable parameter—the system’s total mass, whose change reflects the level of uncertainty in the knowledge of the amount of reserves. The calibration of unsaturated fluxes in each of the models is based on an algorithm developed earlier for local ecosystems, and the measured differences between the fluxes opposite in sign for several times are used to calculate the coefficients of saturated fluxes. The model’s modifications make it possible to estimate the degree to which the oceanic active layer may be involved in rapid exchange with the atmosphere and to introduce the factor of land use as an additional anthropogenic effect. The time trajectories of carbon reserves in reservoirs are calculated until 2100 under variations in anthropogenic emissions in accordance with the IPCC basic scenarios until 2100 for the basic model and its modifications. 相似文献
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Jérôme Harlay Caroline De Bodt Anja Engel Sandra Jansen Quentin d’Hoop Judith Piontek Nicolas Van Oostende Steve Groom Koen Sabbe Lei Chou 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(8):1251-1265
The distribution of transparent exopolymer particles (TEP) was investigated during a coccolithophorid bloom in the northern Bay of Biscay (North Atlantic Ocean) in early June 2006. MODIS chlorophyll-a (Chl-a) and reflectance images before and during the cruise were used to localize areas of important biological activity and high reflectance (HR). TEP profiles along the continental margin, determined using microscopic (TEPmicro) and colorimetric (TEPcolor) methods, showed abundant (6.1×106–4.4×107 L?1) and relatively small (0.5–20 μm) particles, leading to a low total volume fraction (0.05–2.2 ppm) of TEPmicro and similar vertical profiles of TEPcolor. Estimates of carbon content in TEP (TEP-C) derived from the microscopic approach yielded surface concentration of 1.50 μmol C L?1. The contribution of TEP-C to particulate organic carbon (POC) was estimated to be 12% (molar C ratio) during this survey. Our results suggest that TEP formation is a probable first step to rapid and efficient export of C during declining coccolithophorid blooms. 相似文献