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1.
The transport of particulate organic carbon (POC) and particulate trace metals (PTM) to the sea surface by rising bubbles in samples of surface water collected in Narragansett Bay was examined using an adsorptive bubble separation technique. Recoveries of POC ranged from 30 to 59% while those of the particulate form of the trace metals, Al, Mn, Fe, V, Cu, Zn, Ni, Pb, Cr and Cd were generally greater than 50%. The recovery data were used to arrive at a rough order of magnitude estimate of the bubble transport of POC and PTM under open-ocean conditions. While transport rates of the trace metals to the sea surface by both bubble transport and atmospheric deposition varied over approximately 3 orders of magnitude, the ratio of bubble transport to atmospheric deposition for most metals varied over approximately one order of magnitude, perhaps suggesting some degree of coupling between atmospheric PTM and bubble-transported PTM. 相似文献
2.
Seasonal and spatial distribution of particulate organic matter (POM) in the Chukchi and Beaufort Seas 总被引:1,自引:0,他引:1
Nicholas R. Bates Dennis A. Hansell S. Bradley Moran Louis A. Codispoti 《Deep Sea Research Part II: Topical Studies in Oceanography》2005,52(24-26):3324
As part of the Western Arctic Shelf–Basin Interactions (SBI) project, the production and fate of organic carbon and nitrogen from the Chukchi and Beaufort Sea shelves were investigated during spring (5 May–15 June) and summer (15 July–25 August) cruises in 2002. Seasonal observations of suspended particulate organic carbon (POC) and nitrogen (PON) and large-particle (>53 μm) size class suggest that there was a large accumulation of carbon (C) and nitrogen (N) between spring and summer in the surface mixed layer due to high phytoplankton productivity. Considerable organic matter appeared to be transported from the shelf into the Arctic Ocean basin in an elevated POC and PON layer at the top of the upper halocline. Seasonal changes in the molar carbon:nitrogen (C:N) ratio of the suspended particulate organic matter (POM) pool reflect a change in the quality of the organic material that was present and presumably being exported to the sediment and to Arctic Ocean waters adjacent to the Chukchi and Beaufort Sea shelves. In spring, low particulate C:N ratios (<6; i.e., N rich) were observed in nitrate-replete surface waters. By the summer, localized high particulate C:N ratios (>9; i.e., N-poor) were observed in nitrate-depleted surface waters. Low POC and inorganic nutrient concentrations observed in the surface layer suggest that rates of primary, new and export production are low in the Canada Basin region of the Arctic Ocean. 相似文献
3.
Data is presented for the concentrations of organic carbon and nitrogen, and C:N ratios, in marine particulate matter, and for POC and PN, from surface waters collected in the northeastern Atlantic, South Atlantic, Indian Ocean and China Sea.The organic carbon content of this particulate matter varies between 4.6% and 29.9%, and has an average of 17.8%. The average organic carbon content of particulate matter from the various oceans decreases in the order: Northeastern Atlantic > South Atlantic > Indian Ocean > China Sea.The nitrogen content of the particulate matter varies between 1.0% and 3.9%, with an average of 2.2%, and in general follows the same trend as that of organic carbon.C:N ratios vary between 5.1 and 10.6, and have an average of 7.9.The POC contents of the oceanic waters vary between 6.6 and 211 μg/l, with an average of 52 μg/l. The concentrations in the surface waters decrease in the following order: Northeastern Atlantic τ China Sea > South Atlantic > Indian Ocean.The concentrations, and compositions, of particulate matter from various coastal localities are given for comparison with the oceanic values. 相似文献
4.
《Estuarine, Coastal and Shelf Science》2005,62(1-2):95-107
The organic matter (OM) pool has been studied in two sub-arctic north Norwegian fjords, Balsfjord and Ullsfjord, in July 2001 and June 2003. Besides general OM parameters such as dissolved organic carbon (DOC), particulate organic carbon and nitrogen (POC and PON), the distribution of specific compounds such as folic acid and surface active substances (SAS) was followed. The results are supported with data of salinity, temperature, and chlorophyll a (Chl a). This approach allowed assessment of the fate of the OM pool, and its distinct vertical, spatial, and seasonal variations. Fjord waters could be vertically divided into two layers: the upper mixed layer (UML), until 40 m depth, and the deep aphotic layer. Spatial variability between the two fjords is a consequence of different influences of shelf waters on the fjords. Significant enrichment of POC and PON concentrations (3–5 times), as well as those of particulate SAS and folic acid (up to 3.2 times) in the UML was recorded during the period of new production, in early June. Depletion of particulate OM in deep waters was ascribed to fast dissolution or remineralization in the UML or upper part of aphotic layer. OM in July 2001 was characterized with 15.9% higher DOC pool compared to June 2003, and had refractory properties, suggesting the fjords to be an important source of organic matter for the continental shelf ecosystem. The DOC pool in these subarctic fjords represents the major component of the OM pool. The DOC concentrations in fjords are lower than those in previously studied warmer seas (e.g. the Adriatic Sea), whereas the concentrations of folic acid and SAS are comparable to those in the Adriatic Sea. 相似文献
5.
陆架边缘海悬浮颗粒有机质的组成及其来源研究是海洋物质生物地球化学循环研究的重要组成部分。南极的地理位置和气候环境特殊,其边缘海海洋环境受海–气–冰系统共同作用与影响,颗粒有机质的组成及来源具有独特的区域特征与全球意义,其控制因素研究对全面认识罗斯海、阿蒙森海等典型西南极边缘海生物地球化学循环以及生物泵传输效率具有重要的意义。利用中国第36次南极科学考察期间在西南极罗斯海–阿蒙森海区采集的59个表层海水悬浮颗粒物样品的有机碳、氮及其同位素和多种来源特异性的生物标志物分析测试数据,研究了罗斯海–阿蒙森海区域悬浮颗粒物中有机质的物质组成和分布特征,探讨了悬浮颗粒物中不同来源有机质含量与分布的控制因素,评估了不同有机地球化学指标在海–气–冰系统作用下的南极边缘海颗粒有机质组成及来源示踪的应用潜力。研究结果表明,罗斯海–阿蒙森海区海水表层颗粒物中颗粒有机碳(POC)的丰度与表层水体荧光值、海水pCO2、海洋浮游植物源和动物源生物标志物等的丰度分布趋势一致,这种水平分布趋势的一致性表明夏季罗斯海–阿蒙森海海水表层POC主要由浮游植物和动物现场产生。表层悬浮颗粒物总有机质C/N比普遍低于4,显示海区颗粒有机质受微生物降解改造作用明显;表层悬浮颗粒物δ13C值普遍低于−25.2‰,空间分布复杂,反映了南极冰架边缘海独特的贫13C的浮游植物源、富13C的动物源和贫13C的陆源颗粒有机组成的混合信号。表层悬浮颗粒物类脂生物标志物指标是区分不同来源POC组分的有效指标;菜籽甾醇、甲藻甾醇等浮游植物源生物标志物含量之和能较好地反映浮游植物源POC的贡献:近岸冰间湖区呈现高值,其浓度的空间变化受控于水体浮游植物活动;胆甾醇能较好地反映动物源POC的贡献:冰架边缘近岸区呈现高值,其浓度的空间变化受控于海区次级生产力水平和企鹅、海豹等生物量水平;长链的烷基类脂生物标志物较好地反映了南极岩性陆源POC的贡献,其浓度的空间变化受控于南极冰川作用主导的海陆相互作用的过程影响,往往在融冰过程明显的冰架边缘近岸区呈现高值。以上研究结果表明,生物标志物分子指标结合总有机质指标的多参数综合评估为准确辨识南极边缘海复杂的POC来源组成提供了有效的方法,在极区现代海洋(生物地球化学)过程及古海洋环境演化研究中具有广阔的应用空间。 相似文献
6.
黄海、东海颗粒有机碳的分布特征及其影响因子分析 总被引:16,自引:4,他引:16
分析研究了2001年春季黄海、东海颗粒有机碳(POC),结果表明POC的浓度为2~3815μg/dm3,其平面分布呈现近岸高、远岸低的特点.海水表层POC浓度与三磷酸腺苷(ATP)呈显著的正相关,这表明2001年真光层POC主要是海洋生物源.对不同海区POC垂直分布的影响因素做了探讨:长江口附近受总悬浮颗粒物浓度的影响,POC呈现表层低、底层高的特征;陆架区POC的垂直分布是生物活动与水文条件(海水混合、层化)等因素共同作用的结果;在离岸较远的深水区,影响POC垂直分布的主要因素是大洋海水的性质.由海区4个周日连续站的观测结果得知黄海区POC的周日变化主要受生物周日活动的影响,而在东海区POC周日变化除了受生物周日活动影响外,还分别受到潮汐作用以及海水水团周日变化等因素的影响. 相似文献
7.
In three sections in the Kara Sea, the contents of the dissolved and particulate organic carbon (the DOC and POC, respectively),
as well as of the organic carbon of the bottom sediments (Corg) were determined. The contents of varied from 6.3 to 2400 μg/l for the DOC and from 0.84 to 12.2 mg of C/l for the POC. The
average concentrations for all the samples tested amounted to 200 μg/l for the DOC (n = 78, σ = 368) and 2.7 mg/l for the POC (n = 92, σ = 2.7). The concentrations of Corg in the samples of the upper layer of the bottom sediments of the area treated
varied from 0.13 to 2.10% of the dry substance at an average value of 0.9% (n = 21, σ= 0.49%). It is shown that the distribution of the different forms of organic matter (OM) is an indicator of the supply
and spreading of the particulate matter in the Kara Sea and that the DOC and POC of the Kara Sea are formed under the impact
of the runoff of the Ob and Yenisei river waters. It is found that the distribution of the OM of the bottom sediments in the
surveyed area of the Kara Sea is closely related to their grain-size composition and to the structure of the currents in the
area studied. The variations in the Corg content in the bottom sediment cores from the zone of riverine and marine water mixing
represent the variability of the OM burial. 相似文献
8.
Incorporation of 14C-depleted (old) dissolved organic carbon (DOC) on/into particulate organic carbon (POC) has been suggested as a possible mechanism to explain the low Δ14C-POC values observed in the deep ocean [Druffel, E.R.M., Williams, P.M., 1990. Identification of a deep marine source of particulate organic carbon using bomb 14C. Nature, 347, 172–174.]. A shipboard incubation experiment was performed in the Sargasso Sea to test this hypothesis. Finely ground dried plankton was incubated in seawater samples from the deep Sargasso Sea, both with and without a biological poison (HgCl2). Changes in parameters such as biochemical composition and carbon isotopic signatures of bulk POC and its organic compound classes were examined to study the roles of sorptive processes and biotic activity on POC character. Following a 13-day incubation, the relative abundance of the acid-insoluble organic fraction increased. Abundances of extractable lipids and total hydrolyzable amino acids decreased for both treatments, but by a greater extent in the non-poisoned treatment. The Δ14C values of POC recovered from the non-poisoned treatment were significantly lower than the value of the unaltered plankton material used for the incubation, indicating incorporation of 14C-depleted carbon, most likely DOC. The old carbon was present only in the lipid and acid-insoluble fractions. These results are consistent with previous findings of old carbon dominating the same organic fractions of sinking POC from the deep Northeast Pacific [Hwang, J., Druffel, E.R.M., 2003. Lipid-like material as the source of the uncharacterized organic carbon in the ocean? Science, 299, 881–884.]. However, the Δ14C values of POC recovered from the poisoned treatment did not change as much as those from the non-poisoned treatment suggesting that biological processes were involved in the incorporation of DOC on/into POC. 相似文献
9.
10.
11.
Suspended particulate matter was collected, from the water layer at 10 cm above the sediments, over a period of 13 months in the Golfo Marconi (Ligurian Sea, NW Mediterranean). Measurements of seston concentration as well as the elemental (particulate organic carbon and nitrogen; POC and PON, respectively) and biochemical composition (lipids, proteins, carbohydrates, DNA) of particulate organic matter were carried out to assess quality and quantity of food potentially available to benthic suspension-feeders. Particulate organic matter showed wide qualitative and quantitative variations during the sampling year. Seston concentrations and POC did not reflect the quantity and quality of the food available to benthic suspension-feeders. The biopolymeric fraction of particulate matter (C-BPF, i.e. the sum of lipid, protein and carbohydrate carbon) was mostly composed of phytoplankton (which accounted for about 60% of C-BPF). The ratio of C-BPF to POC was utilized as a measure of the fraction which had the potential to be more readily available to consumers. Suspended organic matter showed higher values of the C-BPF:POC ratio during spring, and lower values in summer and autumn–winter. Quantitative estimates of the energy content of the suspended particulate matter were obtained from its biochemical composition. Bacterial dynamics were significantly related to changes in phytoplankton biomass. Bacteria accounted for a significant fraction of the biopolymeric carbon pool (annual average about 15%) and of the total particulate DNA (21·5%), thus enhancing the nutritional value of the particulate organic matter. The results achieved in this study indicate that the biochemical composition of the particulate matter provides additional information on the origin, quality and characteristics of the seston more readily available to benthic suspension-feeders. 相似文献
12.
三峡截流后长江口秋季TSM、POC和PN的分布特征 总被引:2,自引:0,他引:2
基于2004年11—12月长江口56个站位的悬浮体调查资料,分析了长江口区悬浮体总量(TSM)、颗粒有机碳(POC)和颗粒氮(PN)质量浓度的平面分布特征,探讨该区TSM及颗粒有机质的物质来源和三峡截流对长江三角洲的影响。结果表明,表、底层TSM与POC、PN质量浓度之间存在显著的正线性相关关系并都呈现出南高北低的格局,说明了长江悬浮颗粒物入海后主要沿东南方向输运。POC、PN质量分数与POC、PN的质量浓度不同,它们与TSM质量浓度对数有负相关关系。由于河口区底质再悬浮作用显著,TSM和POC、PN质量浓度呈现表层低、底层高的特点。长江口悬浮体主要来自长江径流和底质沉积物的再悬浮。与三峡截流前数据的对比表明,截流对目前长江口区的TSM和POC尚未造成明显的影响。 相似文献
13.
Integrated studies on the hydrochemistry and water column rates of microbial processes in the eastern sector of the Black Sea along a standard 100-miles transect off Gelendzhik from the coast to the central part of the sea at water depths of 100–2170 m show that a series of warm winters and the absence of intense convective winter mixing resulted in a relatively low content of suspended particulate matter (SPM), particulate organic carbon (POC), and nutrients in the water column in March 2009. The relatively high SPM concentrations and the presence of isotopically light POC at the offshore station are indicative of the supply of terrigenous material from land and low contributions of phytoplanktonic organic matter to the composition of SPM. This may explain the low rates of biogeochemical processes in the water column near the coast. The surface layer at deep-water stations is dominated by isotopically heavy phytoplanktonic organic matter. This suggests that the supply of terrigenous material from land was insufficient in offshore deep-water areas. Therefore, warm winters and insufficient nutrient supply do not prevent photosynthesis in the photic layer of the deep-water zone, which generates organic substrates for heterotrophic aquatic communities. The results of isotopic analysis of POC, measurements of the rates biogeochemical processes, and the hydrochemical characteristics of the water column can be used to determine the nature and seasonal variability of the POC composition. 相似文献
14.
Bulk particulate organic carbon in the East China Sea: Tidal influence and bottom transport 总被引:4,自引:0,他引:4
Five oceanographic surveys were carried out in the East China Sea (ECS) and Yellow Sea from 1999 to 2003. In all, seven different sections were surveyed, but one section (the PN section) was observed on every cruise. Two time-series stations were also surveyed, one located at the Changjiang River mouth, the other over the continental shelf in the PN section.We identified biogeochemical characteristics for waters close to the Changjiang Estuary and in the Kuroshio waters (KW), respectively. Resuspension is a strong feature near bottom over the ECS continental shelf, with suspended matter values 13 times higher than that for the surface. A model of particulate organic carbon (POC) dynamics based on a rectangle equation reveals that POC concentration close to the Changjiang Estuary varies with a semidiurnal period of ∼13 h, coinciding with the tidal period. The upper limit for POC residence times in the seasons we covered over the shelf are estimated to be on the order of weeks and generally increase seaward from near the Changjiang Estuary to the KW. Short POC residence times suggest that POC in the ECS is rapidly exported from euphotic waters.A nepheloid layer, observed as elevated suspended matter in near the bottom of the water column, is important in particle transfer over the shelf, especially in winter when the residual current flows mainly eastward. Cross-shelf transport of POC via the nepheloid layer is estimated to be 0.22 × 1012 g yr−1. Comparison with other work indicates that POC transport is ∼2% of the Changjiang POC input. 相似文献
15.
2016年夏季黄、渤海颗粒有机碳的分布特征及影响因素 总被引:1,自引:1,他引:1
本文根据2016年6-7月黄、渤海航次获得的调查数据,分析了黄、渤海海域颗粒有机碳(POC)的浓度变化、空间分布特征并结合盐度、叶绿素a、POC/PON、POC/Chl a平面分布特征和相关性分析,探讨了黄、渤海海域POC的来源和影响因素。结果表明:2016年夏季渤海海域POC平均浓度(500.2±226.5)μg/L,北黄海POC平均浓度(358.2±101.5)μg/L,南黄海POC平均浓度(321.0±158.1)μg/L,渤海海域POC浓度高于黄海,整个海域POC浓度表层高于底层。POC的平面分布特征为近岸高,外海低。调查海域表层POC/PON均值为8.89,POC/Chl a均值为182.52;中层POC/PON均值为8.87,POC/Chl a均值为179.56;底层POC/PON均值为9.41,POC/Chl a均值为178.80。黄海海域浒苔衰败对POC/PON与POC/Chl a影响较大。相关性分析结果表明渤海海域盐度、总悬浮物和叶绿素a与POC存在显著的相关性,是影响POC分布的主要控制因素。南黄海除表层POC浓度与盐度、总悬浮物和叶绿素a浓度有很好的相关性外,中层和底层POC浓度与盐度、总悬浮物和叶绿素a浓度不存在显著的相关性。渤海海域POC主要受陆源和浮游植物共同影响,浮游植物是POC的主要贡献者,而黄海海域POC受长江冲淡水、黄海暖流、苏北沿岸流、生物活动和底层沉积物等多种因素影响,其中苏北近岸和青岛外海,有机碎屑为POC的主要贡献者。 相似文献
16.
Lutz Brügmann 《Marine Chemistry》1988,23(3-4)
Between 1980 and 1984 extensive studies were carried out in the Baltic Sea on trace metals (Cd, Co, Cu, Fe, Hg, Mn, Ni, Pb and Zn) in water, suspended matter and sediments. The results enabled the influence of different factors on metal distribution patterns to be considered. The vertical profiles of dissolved and particulate metals in waters of the central deep basins reflect influences caused by oxygen deficiency and anoxic conditions in near-bottom water layers. Peculiarities at Station BY15 in the Gotland Deep included high dissolved Fe, Mn and Co concentrations and remarkable enrichment of Zn (0.64%), Cd (51 μg g−1) and Cu (0.15%) in particulate matter from the anoxic zone. Manganese-rich particles were accumulated above this layer.In fine-grained soft sediments below anoxic deep waters, maximum contents of Cd, Cu and Zn were observed, relative to other coring sites, between Bothnian Bay and Lübeck Bight. The Hg content in sediments probably reflects the joint flocculation with organic matter. Land-based sources seem to play the leading part for maximum lead contents. 相似文献
17.
长江干流有机碳的时空输运特征及三峡工程对其影响 总被引:1,自引:0,他引:1
2006-04,2008-04,2008-05沿长江干流采集表层水样,并于2006-05~2007-05在下游大通站进行每月2次、为期1 a的连续观测,测定溶解有机碳(DOC)、颗粒有机碳(POC)及总悬浮物(TSM)。结果表明:长江重庆以上江段DOC浓度较低,重庆至河口由于人为污染排放DOC表现出高值;干流POC与TSM显著正先关,POC%(TSM)随TSM含量增大呈负指数关系下降。大通站有机碳浓度及通量均表现出明显的季节性,2006-06~2007-05全年经大通站进入河口的DOC、POC通量分别为1.17×106tC和1.88×106tC,其中洪季(5~10月)输运的有机碳占到总有机碳的70%,组成以颗粒态为主。三峡水库135 m及156 m蓄水后,泥沙在库区的沉降作用显著影响长江POC的输运特征及入海通量;从目前观测结果看,三峡库区DOC浓度并没有表现出明显的升高趋势,可能与水库运行时间尚短有关。 相似文献
18.
Malgorzata Stramska 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(2):284-296
The diffusive component of the particulate organic carbon (POC) export from the ocean's surface layer has been estimated using a combination of the mixed layer model and SeaWiFS ocean color data. The calculations were carried out for several example sites located in the North Atlantic over a 10-year time period (1998–2007). Satellite estimates of surface POC derived from ocean color were applied as an input to the model driven by local surface heat and momentum fluxes. For each year of the examined period, the diffusive POC flux was estimated at a 200 m depth. The highest flux is generally observed in the spring and fall seasons, when surface waters are weakly stratified. In addition, the model results demonstrate significant interannual and geographical variability of the flux. The highest diffusive POC flux occurs in the northern North Atlantic and the lowest in the subtropical region. The interannual variability of the diffusive POC flux is associated with mixed layer dynamics and underscores the importance of atmospheric forcing for POC export from the surface layer to the ocean's interior. 相似文献
19.
夏季黄东海颗粒有机碳的分布特征 总被引:2,自引:0,他引:2
根据2006年6~7月对黄东海大面调查的资料,分析研究了黄东海颗粒有机碳(particulate organic carbon,POC)的浓度和分布特征。结果表明,夏季黄东海POC的浓度范围是6.07~2 204.17μg.L-1,平均浓度为147.15μg.L-1。POC整体上呈现近岸浓度较高、远岸浓度较低,北部浓度较高,南部浓较低的分布特点;在长江口外及浙江近岸海区存在POC的高值区,特别是长江口外,表层和底层POC浓度很高,这主要是受到长江陆源输入的重要影响。在垂直分布上,南黄海区POC的浓度分布整体上呈现上层水体浓度较低,下层水体浓度较高的特点,这主要是受底质再悬浮的影响。而东海区呈现近岸POC浓度较高,离岸POC浓度较低的特点,这主要是受长江冲淡水输入的影响。 相似文献
20.
Particular features of the distribution of the transparency and particulate matter content, their variability, and their interdependence in the surface water layer (0–5 m) over the northwestern shelf and in the adjacent abyssal part of the Black Sea in the summer were considered on the basis of long-term simultaneous optical, biological, and hydrological observations (1979–1993). In the shelf regions with different river discharges and in the waters of the open part of the sea, the distributions of the transparency, the total particulate matter, and its organic components (organic carbon, nitrogen, and chlorophyll a), as well as the relative content of particulate organic carbon in the total amount of the particulate matter and the content of chlorophyll a in the particulate organic carbon, were considered. The distributions of the transparency and particulate matter and their dependence on the water dynamics are in good agreement. It was demonstrated that extreme anthropogenic eutrophication influences the western and northern coastal shelf areas. The water transparency and particulate organic matter distributions in the central shelf area subjected to the influence of transformed river water and the water properties of the southern part of the shelf, which is influenced by the waters of the open sea, were determined according to the particular structure of the phytoplankton, its abundance, and the processes of its production and destruction. 相似文献