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961.
Darcy L. Gray Rosaline R. Canessa C. Peter Keller Philip Dearden Rick B. Rollins 《Marine Policy》2011
Information about spatial patterns of recreational boating is important for managing environmental, safety, and social impacts. However, traditional spatial mapping techniques such as remote sensing are often unable to project entire vessel routes or to link with other important data such as demographics, activities, or purpose of trip. This study, conducted in a part of Canada’s southern Strait of Georgia, uses an on-the-water-questionnaire to map recreational boating distribution/density in a complex, multiple-use marine setting. Goals of this study were to explore an on-the-water questionnaire as a means of capturing boating distribution and density, explore the potential contributions of such information to marine spatial planning, and assess the strengths and limitations of the method. Boaters (n=519) were intercepted while engaged in boating trips and were asked to plot the route of their trip on a map of the region. Information was imported into ArcGIS for analysis and display of vessel distribution and density. The resultant spatial dataset has a number of applications for marine spatial planning and management. Strengths of this method include collection of entire vessel routes, linking spatial data to questionnaire variables, and a high response rate. Limitations include some bias towards sample sites and issues of respondent accuracy, as well as cost and effort. Recommendations for management and research are made. 相似文献
962.
963.
研究了海洋磁力测量多站日变改正值的计算方法,采用多站同步实例分析了加权平均法和函数拟合法在海洋磁力测量地磁日变改正中的应用,探讨了适合海洋磁力测量特点的多站日变改正值计算方法.结论表明:加权平均法和函数拟合法是多站日变改正值计算的有效方法.忽略经度效应的影响,采用纬距加权或纬度坐标拟合,可以改善加权平均法或函数拟合法效果.海洋磁力测量日变站大多建在测区附近的沿岸,导致多个日变站网的图形结构较差,建议采用纬距加权平均法. 相似文献
964.
Essential ecological insights for marine ecosystem-based management and marine spatial planning 总被引:2,自引:2,他引:2
The abrupt decline in the sea's capacity to provide crucial ecosystem services requires a new ecosystem-based approach for maintaining and recovering biodiversity and integrity. Ecosystems are places, so marine spatial planners and managers must understand the heterogeneity of biological communities and their key components (especially apex predators and structure-forming species), and of key processes (e.g., population connectivity, interaction webs, biogeochemistry) that maintain them, as well as heterogeneity of human uses. Maintaining resistance and resilience to stressors is crucial. Because marine populations and ecosystems exhibit complex system behaviors, managers cannot safely assume they will recover when stressors are reduced, so prevention is a far more robust management strategy than seeking a cure for degraded systems. 相似文献
965.
Pier Paolo Bruno 《Bulletin of Volcanology》2004,66(4):342-355
Digital marine seismic reflection data acquired in 1973 in the Bay of Pozzuoli, and recently reprocessed, were used to study the volcanological evolution of the marine sector of Campi Flegrei Caldera during the last 37 ka. In order to gain more information, interpretation also involved estimation of the "pseudo-velocity" and the "pseudo-density" from the resistivity logs of two onshore deep exploration wells. The main results are: (1) discovery of ancient pre-18 ka and post-37 ka submarine and mainly effusive volcanic activity, along coeval emission centers located at the edges of Campi Flegrei Caldera; (2) confirmation that the caldera collapse in the marine sector of Campi Flegrei seems strongly controlled by regional NE–SW and NW–SE structural discontinuities; (3) the finding of at least two episodes of collapse in the bay; and (4) identification of a post-18 ka volcanic deflation phase that has caused about 150–200 m of subsidence in the central sector of the Bay of Pozzuoli in the last 18 ka.Editorial responsibilty: T. Druitt 相似文献
966.
本文通过对长城湾表层沉积物中稀土元素的地球化学研究,认为其总量丰度、配分模式、特征参数等,均与菲尔德斯半岛的火山岩相似,因而长城湾沉积物的主要来源似为菲尔德斯半岛基岩的风化产物。 相似文献
967.
为进一步培育和壮大我国海洋高技术产业,促进海洋经济的高质量发展,文章梳理和评价天津市等8个国家海洋高技术产业基地试点及其重点产业的发展情况,并提出发展建议。研究结果表明:作为首批国家海洋高技术产业基地,天津市等8个城市重点发展海洋高端装备制造、海洋医药与生物制品、海洋生物育种与健康养殖、海水利用以及海洋高技术服务等海洋高技术产业,在产业集聚、科技创新、产品和技术研发以及管理服务等方面取得显著成效,有力促进区域海洋经济发展,但仍存在产业规模较小和成果转化较弱等问题,未来应加大政策扶持、建立互动机制、推动成果转化和加强金融支撑,持续深入推进海洋高技术产业基地建设及其产业发展。 相似文献
968.
Martin Mühling Adam Bradford James W. Readman Paul J. Somerfield Richard D. Handy 《Marine environmental research》2009,68(5):278-283
The aim of this study was to test whether silver nanoparticles (Ag-NPs) released into estuarine environments result in increased antibiotic resistance amongst the natural bacterial population in estuarine sediments. A 50-day microcosm exposure experiment was carried out to investigate the effects of Ag-NPs (50 nm average diameter) on the antibiotic resistance of bacteria in sediments from an estuary in southwest England. Experimental microcosms were constructed using 3.5 kg sediment cores with 20 l of overlaying seawater treated with (final) Ag-NPs concentrations of 0, 50 or 2000 μg l−1 (n = 3). Sediment samples were screened at the end of the exposure period for the presence of bacteria resistant to eight different antibiotics. Multivariate statistical analyses showed that there was no increase in antibiotic resistance amongst the bacterial population in the sediment due to the dosing of the microcosms with Ag-NPs. This study indicates that, under the tested conditions, Ag-NPs released into the coastal marine environment do not increase antibiotic resistance among naturally occurring bacteria in estuarine sediments. These results contrast previous findings where antimicrobial effects of Ag-NPs on key bacterial species in laboratory experiments have been demonstrated, and reasons for this are discussed. The negligible effects demonstrated on bacterial populations under the selected estuarine conditions, provide important information on no observed effect concentrations (NOECs) for environmental regulation. 相似文献
969.
For certain critical equipment items in marine machinery systems, the optimum maintenance strategy would be a scheduled on-condition operation. This involves inspection of the equipment items in order to monitor their performance degradation and, invariably, carry out repair or replacement tasks. The main challenge with this type of maintenance approach is the determination of the appropriate interval for performing the inspection task. This paper presents a methodology which integrates multi-criteria decision making (MCDM) tools with a delay time model for the determination of optimum inspection intervals for marine machinery systems. With this approach, multiple decision criteria are modelled with the delay time concept and aggregated with MCDM tools such that different criteria can be applied simultaneously in the ranking of different inspection interval alternatives. The applicability of the proposed methodology is demonstrated using the case study of a water cooling pump of the central cooling system of a marine diesel engine. 相似文献
970.
海面风场的数值预报业务模式 总被引:1,自引:2,他引:1
海面风场的业务数值预报,经过六年的运行和不断改进,目前已建立了包括资料处理、客观分析、大气模式和边界展模式在内的数值预报业务化系统,它能提供15°~45°N、1h5°~141°E海域内1°×1°经纬网格点上的72小时的预报风场,该风场除为日常业务预报提供参考外,还为海浪和海冰业务模式提供强迫场。本文主要介绍大气模式和边界层模式的概况以及系统的运行结果。 相似文献