Organic matter origin and distribution in suspended particulate materials and surficial sediments from the western Adriatic Sea (Italy)   总被引：5，自引：2，他引：5  

T. Tesi  S. Miserocchi  M.A. Goi  L. Langone  A. Boldrin  M. Turchetto 《Estuarine, Coastal and Shelf Science》2007,73(3-4):431-446

In this study, organic carbon (OC), total nitrogen (TN), stable carbon isotopic (δ¹³C_OC) and CuO reaction product compositions were used to identify the sources of organic matter (OM) and to quantify the relative importance of allochthonous and autochthonous contributions to the western Adriatic Sea, Italy. Suspended particulate material (195 samples) and surficial sediments (0–1 cm, 70 samples) from shallow cross-shelf transects were collected in February and May 2003, respectively. Vertical water column profiles were acquired along the same transects. Data include depth, potential temperature, salinity, density and chlorophyll fluorimetry.Along the western Adriatic shelf in the near-shore region, the phytoplankton growth was influenced by dynamics of the buoyant plumes from the Po and Appennine rivers. A small amount of very fine terrigenous material remained suspended within the coastal current and was exported southward along the shelf to the slope. High variability in the bulk composition was detected in the Po prodelta surficial sediments, whereas the western Adriatic shelf, although a larger area, exhibited a narrower range of values.A significant decoupling was observed between suspended particles in the water column and surficial deposits. The organic material collected in the water column was compositionally heterogeneous, with contributions from marine phytoplankton, riverine–estuarine phytoplankton and soil-derived OM. Frequent physical reworking of surficial sediments likely leads to the efficient oxidation of marine OC, resulting in the observed accumulation and preservation of refractory soil-derived OC delivered by the Po and Appennine rivers.  相似文献   

大气中的有机氮化合物及其向海洋的沉降     

毕言锋  刘素美  张经 《海洋科学进展》2006,24(4):604-610

近几年的研究表明,有机氮化合物是大气氮沉降的重要组成部分,对全球氮循环的贡献不可忽视。介绍了大气中有机氮化合物的组成、测定方法以及存在的问题,综述了大气有机氮化合物向海洋沉降的研究现状及其对海洋生态系统的影响,并探讨了未来的研究重点。  相似文献   

海洋古生产力重建初探──以南沙群岛海区NS90-103柱样为例     

吴时国  涂霞  罗又郎 《海洋科学》1996,20(2):47-51

以南沙海区ＮＳ９０－１０３柱样为例，利用各种古生产力指标物，如有机碳含量，有孔虫壳和有孔虫碳同位素，重建了２０００００ａ以来古生产力变化，并对结果予以讨论。  相似文献   

浙江西沪港重金属铜的配位容量和形态分析   总被引：3，自引：2，他引：3       下载免费PDF全文

吕海燕  王正方  傅和芳  冯旭文 《海洋学报》2003,25(3):47-52

根据2000年6月10～14日在浙江省西沪港采集的海水样品,利用AA-800石墨炉原子吸收分光光度技术和阳极溶出伏安法测定样品中重金属铜的含量,获得铜在海水中受不同的有机配体控制.不同粒级的铜表观配位容量表明西沪港海水过孔径1.00μm微孔膜的(ACuCC)较高,为144.4nmol/dm3;过0.40和0.20μm滤膜的(ACuCC)分别为103.0和102nmol/dm3;铜的有机配体条件稳定常数的对数值在7.25～9.14之间.铜的总量为21.72nmol/dm3.铜全部为稳定溶解态,其中pH2酸溶态占95.0%,强有机结合态占5.0%.溶解态铜中有机结合态占过滤海水中总铜的61.6%.  相似文献   

Distribution of dissolved organic carbon in and near the Prydz Bay, Antarctica     

Qiu Yusheng  Chen Min  Huang Yipu  Liu Guangshan 《海洋学报(英文版)》2003,22(4):547-556

INTRODUCTIONDissolvedorganiccarbon (DOC)makesupthesecondlargestofthebioactivepoolsofcar bonintheocean ,secondtothelargestpoolofdissolvedinorganiccarbon .Theglobaldissolvedorganiccarbonpoolisestimatedtobe 6 85Gt,avaluecomparabletothemassofCO2 intheat mosphere (Hedges,1 992 ) .Thesizeofthereservoir,aswellasitsdynamics ,indicatesthatDOCplaysacentralroleintheoceancarboncycle .AsitrelatestogreenhousegasessuchasCO2 andassociatesclimatecycle ,oceanicDOCbiogeochemicalcycleshavebeenoneoftheh…  相似文献   

对虾养殖生态系中有机碳的初步研究本研究由   总被引：1，自引：0，他引：1  

游奎  马甡 《中国海洋大学学报(自然科学版)》2002,32(1):51-55

对于围隔养殖对虾生态系中有机碳的变动进行了研究 ,结果表明 :溶解有机碳 (DOC)含量波动在 5 .2 99～ 13.39mg/ L之间 ,平均为 8.5 3mg/ L± 2 .2 5 mg/ L;颗粒有机碳 (POC)含量波动在0 .6 5～ 6 .6 3mg/ L之间 ,平均为 3.2 5 mg/ L± 1.76 mg/ L;总有机碳 (TOC)含量波动在 6 .92～ 2 0 .0 2mg/ L之间 ,平均为 11.78mg/ L± 3.82 mg/ L ;其中 DOC∶ POC∶ TOC为 0 .72∶ 0 .2 8∶ 1。各种有机碳组分的含量明显高于自然海水中各种有机碳的含量 ;各种有机碳组分的含量在养殖期间总体上呈上升的趋势 ;其变化与 DCOD的变化呈显著线性正相关的关系。  相似文献   

台湾海峡中北部上升流区各种形态磷的化学特性   总被引：4，自引：0，他引：4       下载免费PDF全文

陈水土 《海洋与湖沼》1993,24(6):664-670

根据１９８８年７月调查资料讨论了台湾海峡中北部海域夏季上升流区各种形态磷的分布特征。结果表明，上升流中心区（即海坛岛东侧一带水域）具有低温、高盐、低溶解氧；ＤＩｐ，ＴＤＰ，ＰＰ，ＴＰ较高；ＤＯＰ较低（０．２７）；及ＤＩＰ／ＤＯＰ比值（约为１）较高的特性。ＤＯＰ是该海域磷的主要形态（占ＴＰ的４９．２％），其含量分布及其形态转化与生物活动直接相关，是该海域生物生产力高的体现。  相似文献   

Local remineralization patterns in the mesopelagic zone of the Eastern North Atlantic, off the NW Iberian Peninsula     

C.G. Castro  M. Nieto-Cid  X.A. lvarez-Salgado  F.F. Prez 《Deep Sea Research Part I: Oceanographic Research Papers》2006,53(12):1925-1940

The short-time-scale variability of the remineralization patterns in the domain of Eastern North Atlantic Central Waters (ENACW) off the NW Iberian Peninsula is studied based on biogeochemical data (oxygen, nutrient salts, total alkalinity, pH, dissolved organic matter and fluorescence of dissolved humic substances) collected weekly between May 2001 and April 2002. The temporal variability of inorganic variables points to an intensification of remineralization during the summer and autumn, with an increase of nutrients, total inorganic carbon and fluorescence and a decrease of oxygen. During the subsequent winter mixing, there is a biogeochemical reset of the system, with lower nutrients, total inorganic carbon and fluorescence and higher oxygen. In contrast to inorganic variables, the levels of dissolved organic matter in the ENACW seem to respond to short-term events probably associated with fast sinking particles, where solubilisation of organic matter prevails over remineralization. Applying a previously published stoichiometric model, we observed a vertical fractionation of organic-matter remineralization. Although there is a preferential remineralization of proteins and P compounds in the entire domain of ENACW, the percentage was higher in the upper ENACW (σ<27.10 kg/m³) than in the lower; the percentage of N and P compounds in the oxidised organic matter was >80% for the upper ENACW and 63% for the lower. Likewise, the redissolution of calcareous structures contributes about 6% and 13% to the carbon regenerated in the upper and lower layers of ENACW, respectively.  相似文献   

Vertical Distribution of Meiobenthos in Bathyal Sediments of the Eastern Mediterranean Sea: Relationship with Labile Organic Matter and Bacterial Biomasses     

Roberto  Danovaro  Mauro  Fabiano  Giancarlo Albertelli  Norberto Della  Croce 《Marine Ecology》1995,16(2):103-116

Abstract. Quantitative information on the vertical distribution of meiofaunal abundances and biomass were obtained from samples collected at 3 bathyal stations in the Eastern Mediterranean Sea located at the same depth but characterized by different food supply. Vertical distribution patterns of nieiofauna were investigated in relation to the biochemical composition of the sediment organic matter (proteins, carbohydrates, and lipids) and compared to benthic bacterial standing stocks. No significant relationship between bacteria and meiofauna was found, whereas a significant relationship between protein and lipid concentrations and total meiofauna density was observed. These data suggest that labile organic matter. considered as material readily aVdihbk to benthic consumers, may be an important factor regulating meiofaunal abundance and vertical distribution in deep-sea sediments.  相似文献   

Carbon Isotope Geochemistry of the Orinoco Basin     

F. C. Tan  J. M. Edmond 《Estuarine, Coastal and Shelf Science》1993,36(6)

Stable carbon isotope ratios have been used to study the sources of particulate organic carbon (POC) and total dissolved inorganic carbon in the Orinoco Basin. The isotopic composition of total dissolved inorganic carbon shows a range of from -8·1 to -23·0 ppt, an indication of dominance of biological processes. The isotopic composition of POC exhibits a range of from -24·1 to -34·6 ppt with little seasonal variation. The isotopic evidence indicates that the POC is predominantly of terrestrial origin rather than a result of in situ planktonic production. The similarity of isotopic composition of POC and coastal sediments suggests that riverine organic detritus has been transported 30-50 km offshore in a direction parallel to the Orinoco river channel.  相似文献