Denitrification in Qi'ao Island coastal zone, the Zhujiang Estuary in China   总被引：1，自引：0，他引：1  

WANG Hu  ZHOU Huaiyang  PENG Xiaotong  YANG Qunhui  QIN Chaomei  YIN Xijie  CHEN Guangqian 《海洋学报(英文版)》2009,28(1):37-46

Samples of sediments and the overlying water were collected in the Qi'ao Island coastal zone, the Zhujiang (Pearl River) Estuary (ZE). Denitrification rates, sediment oxygen demand (SOD) , and fluxes of inorganic nitrogen compounds were investigated with N2 flux method, using a self-designed continuous flow through and auto-sampling system. The results indicate that the denitrification rates varied between 222 and 908 μmol/(m2·h) with an average of 499 μmol/(m2·h). During incubation, the sediments absorbed dissolved oxygen in the overlying water with SOD ranging from 300 to 2 363 μmol/(m2·h). The denitrification rates were highly correlated with the SOD (r2 =0.77) regardless of the NO3- + NO2- concentrations in the overlying water, organ- ic carbon contents in sediments and water temperature, suggesting that the SOD was probably the main environ-mental factor controlling the denitrification in the Qi'ao Island coastal zone. There was a net flux of NO3- + NO2-into the sediments from the overlying water. The NH4+ flux from sediments into water as the result of mineraliza-tion was between 12. 3 and 210. 3 μmol/(m2·h) ,which seems limited by both organic carbon content in sedi-ment and dissolved oxygen concentration in the overlying water.  相似文献   

The application of hyperspectral remote sensing to coast environment investigation   总被引：1，自引：0，他引：1  

ZHANG Liang  ZHANG bing  CHEN Zhengchao  ZHENG Lanfen  TONG Qingxi 《海洋学报(英文版)》2009,28(2):1-13

Requirements for monitoring the coastal zone environment are first summarized. Then the application of hyperspectral remote sensing to coast environment investigation is introduced, such as the classification of coast beaches and bottom matter, target recognition, mine detection, oil spill identification and ocean color remote sensing. Finally, what is needed to follow on in application of hyperspectral remote sensing to coast environment is recommended.  相似文献   

Coloured dissolved organic matter (CDOM) in Southern North Sea waters: Optical characterization and possible origin   总被引：1，自引：0，他引：1  

Rosa Astoreca  Véronique Rousseau  Christiane Lancelot 《Estuarine, Coastal and Shelf Science》2009

The variability and origin of the Coloured Dissolved Organic Matter (CDOM) were studied in the Belgian coastal and adjacent areas including offshore waters and the Scheldt estuary, through the parameters: absorption at 375 nm, a_CDOM(375), and the slope of the absorption curve, S. a_CDOM(375) varied between 0.20 and 1.31 m⁻¹ and between 0.97 and 4.30 m⁻¹ in the marine area and Scheldt estuary, respectively. S fluctuated between 0.0101 and 0.0203 nm⁻¹ in the marine area and between 0.0167 and 0.0191 nm⁻¹ in the Scheldt estuary. The comparative analysis of a_CDOM(375) and S variations evidenced different origins of CDOM in the BCZ. The Scheldt estuarine waters showed decreasing a_CDOM(375) values with increasing salinity but constant S value of ∼0.018 nm⁻¹ suggesting a dominant terrestrial origin of CDOM. On the contrary, samples collected in the marine domain showed a narrow range of a_CDOM(375) but highly variable S suggesting the additional presence of autochthonous sources of CDOM. This source was evidenced based on the sorting of the marine offshore data according to the stage of the phytoplankton bloom when they were collected. A clear distinction was made between CDOM released during the growth stage characterized by high S (∼0.017 nm⁻¹) and low a_CDOM(375) and the decay phase characterized by low S (∼0.013 nm⁻¹) and high a_CDOM(375). This observation was supported by CDOM measurements performed on pure phytoplankton cultures which showed increased CDOM release along the wax and wane of the bloom but decreasing S. We concluded that the high variability of the CDOM signature in offshore waters is explained by the local biological production and processing of CDOM.  相似文献   

Impacts of maintenance channel dredging in a northern Adriatic coastal lagoon. II: Effects on macrobenthic assemblages in channels and ponds     

Massimo Ponti  Andrea PasterisRoberta Guerra  Marco Abbiati 《Estuarine, Coastal and Shelf Science》2009

Coastal lagoons are ephemeral habitats whose conservation requires human intervention, such as maintenance dredging of inner channels. Dredging can reduce the abundance of benthic species due to the removal of individuals with the sediment, modify sediment properties, and resuspend fine sediment, nutrients and pollutants, which can lead to eutrophication, hypoxic events and increasing toxicity. Both direct effects in the dredged channel and possible indirect effects in surrounding shallow areas could be expected. This study assesses the effects of the channel maintenance dredging, performed between October 2004 and August 2005, on the invertebrate assemblages both in channels and adjacent ponds in the northern Adriatic coastal lagoon of Pialassa Baiona. The lagoon is affected by eutrophication, chemical and thermal pollution from wastewater treatment and power plants. Three impacted sites were located in the dredged channel and three in the adjacent interconnected shallow water ponds, while three non-impacted sites were located in a channel and in a pond far from the dredged area. Replicate samples were collected from each site one time before and one time after the dredging operations. Despite the extent of the intervention, effects of the dredging on macrobenthic assemblages were detected only within the dredged channel, while in the surrounding ponds no clear and unequivocal effects were found. In particular the dredging could have promoted the increase of the abundance of the polychaete Streblospio shrubsolii in the southern and central parts of the dredged channel and the increase in abundance of the amphipod Corophium insidiosum in the northern side, compared to the controls. Instead, species diversity was reduced in the central and northern parts of the dredged channel. These effects on the macrobenthic invertebrate assemblages could be related to the observed changes of sediment characteristics, contamination and toxicity. Overall, direct effects on benthic assemblages in the dredged channels were more detectable than the possible secondary effects in the surrounding shallow ponds, where the higher spatial heterogeneity can mask any relevant effects.  相似文献   

The role of research networks for science-policy collaboration in coastal areas     

T.A. Stojanovic  I. Ball  R.C. Ballinger  G. Lymbery  W. Dodds   《Marine Policy》2009,33(6):901

This paper reviews the approach taken by several UK coastal partnerships in developing research strategies and programmes. It reports on the status of these research initiatives and describes how the co-ordination and communication of scientific research have been approached through active partnerships with universities and the wider research community. Results of semi-structured interviews are followed by in-depth case studies of research networks on the Sefton Coast (focusing on coastal morphology) and the Severn Estuary (focusing on coastal change and climate change impacts). The results reveal the constraints and opportunities that exist in bringing together a variety of knowledge holders in the coastal zone. The paper identifies key elements of these initiatives and highlights lessons that can be applied to the development of other research initiatives in order to achieve science supported, ecosystem-based management.  相似文献   

The application of geographic information technology to coastal geomorphology     

GUOWei  LIShuheng  ZHUDakui 《海洋学报(英文版)》2009,28(5):49-57

With the development of modern oceanic observation technologies,coastal survey data have been experiencing a substantial growth.The integration management of the data from different disciplines,different sources and different formats has become a major research field in coastal geomorphology by using Geographic Information System (GIS).This paper puts forward a new methodology framework of GIS techniques in coastal ocean geomorphology,including data acquisition,process,analysis,and representation.It focuses on some major GIS techniques to study the land-ocean interaction mechanism,such as spatial analysis,submarine topography model and three-dimension (3D) visualization,and apply its result to coastal urban planning,harbor site selection and geomorphology environment about coral reef and islands on the continental shelf.The case studies cover the whole coastal ocean to serve the social community,economical development and diplomatic rights for decision-making all round in the coastal zone.The research shows clearly that the application of coastal multi-source geospatial platform has changed the traditional coastal geomorphology science dramatically from its research scope,fields and methods,however,as made clear in this paper,extracting accurate information from remote sensing data and GIS databases for coastal geomorphological applications is a nontrivial challenge that requires the combined knowledge and skills of information scientists and geomorphologists.  相似文献   

Response of BITS (a benthic index based on taxonomic sufficiency) to water and sedimentary variables and comparison with other indices in three Adriatic lagoons     

Cristina Munari  Elena Manini  Antonio Pusceddu  Roberto Danovaro  & Michele Mistri 《Marine Ecology》2009,30(2):255-268

The European Water Framework Directive (WFD, 2000/60/EC) recommends the development of biotic indices for assessing the ecological quality status of water bodies. The Benthic Index based on Taxonomic Sufficiency (BITS) was specifically developed for lagoonal systems, according to the tolerant/opportunistic approach. Macrobenthic data, variables indicative of eutrophication and variables indicative of sedimentary organic matter quality were collected during 18 surveys carried out between 2004 and 2005 in three Adriatic coastal lagoons (Venice Lagoon, Sacca di Goro, Lesina Lagoon). The relationship between environmental variables and biotic indices (AMBI, BENTIX, BITS, BOPA and FINE) was tested using multivariate analyses. Indices based on species classification level appeared to relate better with the variables describing organic matter quality, whereas BITS, which is based on family classification level, seemed related to eutrophication indicative variables, such as sulphide, ammonium, dissolved oxygen and orthophosphate concentrations. The BITS approach reduces the costs associated with sorting and identification of organisms. Providing a rapid assessment of ecological quality, and producing an ecologically relevant classification, BITS seems a promising tool for monitoring programs of Adriatic lagoonal ecosystems. Its sensitivity in reflecting the field conditions elsewhere, however, remains to be assessed.  相似文献   

海南岛西北部莲花山周缘海相地层的区内对比及意义     

姚衍桃  詹文欢  孙金龙  刘再峰  詹美珍 《海洋地质与第四纪地质》2009,(3)

根据岩性、产状和地貌等特征,对海南岛西北部莲花山周缘海岸出露的前全新世海相地层5个典型剖面进行区内对比,以恢复该套地层的产出序列,并推测海相地层的分布范围。结合海相地层的沉积时代和莲花山周缘海岸的地貌特征,探讨了该海岸带的地貌演化过程:中更新世以前,有河流自东南向西北经德义岭、莲花山入海,海相地层沉积区属于滨岸环境,是该海岸带当时受海水进退作用的主要区域,接受着波浪从北面、河流从南面带来的沉积物;中更新世至今,受雷琼地区火山活动的影响,河流被隆起的火山锥阻挡而截流或改道,海相地层沉积区则被抬升成为陆地,并在全新世海岸侵蚀作用下,形成了现今宽广的海蚀平台,海岸后退平均速率约为10 cm/a。  相似文献   

Development of a typology for transitional waters in the Mediterranean ecoregion: The case of the islands     

Paloma Lucena-Moya  Isabel Pardo  Maruxa Álvarez 《Estuarine, Coastal and Shelf Science》2009

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Resolving physically and biologically driven suspended particulate matter dynamics in a tidal basin with a distribution-based model   总被引：1，自引：0，他引：1  

Joeran Maerz  Kai Wirtz 《Estuarine, Coastal and Shelf Science》2009

Understanding suspended particulate matter (SPM) dynamics in coastal waters is crucial to assess changes in coastal sediment budgets and biogeochemical fluxes. SPM dynamics are subject to various physical and biological factors and processes such as, e.g. tidal currents and aggregation which can be enhanced by extracellular polymeric substances (EPS) that are produced by algae and bacteria. It is still unclear how the different factors and processes interact and together determine SPM dynamics. To unravel the interacting processes and factors, we propose a new distribution-based modeling approach. Based on the derivation of explicit equations for size distribution characteristics of SPM such as the average radius, we derived a model of reduced complexity characterized by low initialization and parameterization effort as well as low computational cost. The proposed 0D model includes the processes of aggregation and fragmentation due to shear, aggregation due to differential settling, deposition, resuspension and tidal exchange, and describes the evolution of the SPM concentration in the water column linked by the settling velocity to the change of the mass average radius of the aggregate distribution. A systematic parameter variation for critical bottom shear stress of erosion, the size of resuspended aggregates, the fractal dimension, the collision efficiency, and the aggregate strength has been performed and compared to observations in the back-barrier basin of Spiekeroog Island in the German Wadden Sea. This analysis confirms the hypothesis that in winter biological influences on SPM dynamics are smaller compared to summer. This is mainly reflected by a significant shift in the various parameters. We hence conclude that biological control mechanisms have a much more quantitative relevance for SPM dynamics than currently represented by state-of-the-art SPM transport models.  相似文献