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1.
UK shipping companies increasingly flagged out their ships from the 1970s to the late 1990s. This study used Lloyd's casualty records from 1970 to 2005 to investigate and compare shipping casualties and crew fatalities in UK shipping, UK second registers (Bermuda, Cayman Islands, Gibraltar, Hong Kong and the Isle of Man) and six foreign flags (Bahamas, Belize, Cyprus, Malta, St. Vincent and Vanuatu) used frequently by UK shipping companies. The study also assessed how 12 shipping factors may affect ships foundering and crew fatalities. Shipping casualty and crew fatality rates fell over time in UK shipping, in UK second registers and in older flags of conveniences, rather than in newer flags of convenience such as Belize and St. Vincent. Cargo, trade and weather most strongly affected ships foundering and crew fatalities. The findings indicate that shipping casualties and crew fatalities should be monitored in new and rapidly expanding flags of convenience.  相似文献   

2.
Previous models of the evolution of Hurst Castle Spit over-emphasised longshore growth at the expense of other processes, particularly rise in sea-level. Initially, a Pleistocene valley system was submerged creating a tidal strait, the West Solent, between Christchurch Bay and the East Solent. This almost certainly caused a major hydrodynamic change, transforming much of Christchurch Bay and the West Solent from a low to a high tidal energy environment. Hurst Castle Spit and the Shingles Bank then began to form due to a combination of an easterly littoral drift, offshore gravel movement due to the high tidal energy, a rising sea-level, the transgression of Hurst Beach due to overwashing and the formation of recurves due to waves in the West Solent. The growth of the Shingles Bank due to offshore sediment movement from Hurst Castle Spit was of particular importance because of its influence on the wave energy along Hurst Beach. Significant local supplies of shingle in the vicinity of Hurst Castle Spit, reworked from Quatenary deposits, were also of importance. Thus, it is not a classic multi-recurved spit and the transgressive segment, Hurst Beach, has much in common with barrier coastlines.The same processes are continuing to shape Hurst Castle Spit at present, with the additional effects of human interference in the coastal sediment system. The construction of sea defences at Milford-on-Sea in the period 1936 to 1968 has modified the sediment budget and Hurst Castle Spit is experiencing a phase of rapid evolution: maximum recession rates have increased from 1.5m a−1 (1867–1968) to 3.5m a−1 (1968–1982). It is difficult to quantify the exact role of sea-level rise in the present evolution of Hurst Castle Spit.The future evolution of Hurst Castle Spit will depend largely on man. If there is no further interference, which is highly unlikely, the beach volume will continue to decline, resulting in a further increase in the rate of recession. Ultimately, a true tidal breach will probably form, marking a new phase in the evolution of Hurst Castle Spit and its environs. However, shingle renourishment, or another coastal engineering solution will probably be undertaken. The future rate of sea-level rise will have important long-term influences on all these options.  相似文献   

3.
In order to expand registered fleet tonnage and strengthen ship management, China began to introduce a special tax-free ship registration (STFSR) policy in July 2007. However, more than eight years following its implementation, the policy ended in complete failure at the end of 2015. This paper comprehensively evaluates the main content and implementation process of the Chinese STFSR policy, analyzes the effects of the policy, and summarizes the concrete reasons for the policy's failure and lessons to be learnt. A new governance framework is being designed and future directions are being developed to explore how the government can implement a successful ship registry policy. This research is intended to provide new ideas and information to the Chinese shipping industry's policymakers and stakeholders in order to handle the “flagging out” problem, thereby mitigating the current adverse situation of ship flagging overseas while strengthening the management of ship operation.  相似文献   

4.
The biotransformation of xenobiotics by microsomal cytochromes P450 is known to be pivotal in the effects of some compounds, and thought to be so for many. A knowledge of CYP gene diversity and CYP function and regulation in aquatic species is pursued, expecting that it will disclose mechanisms, allow predictions regarding species differences in susceptibility, and provide markers for exposure to xenobiotics. As well, it is hoped that such knowledge will provide clues to CYP endogenous functions, and to the origin and functional significance of CYP gene diversity. The knowledge of CYP in marine and other aquatic species is expanding rapidly. The diversity of CYP genes in non-mammalian vertebrates may approximate that in mammals. At present, cloning studies have identified members of gene families 1 to 4 have been cloned from one or more fish species. Where known, the gene structures of fish CYP genes are like those of mammalian homologues. Only one CYP1A gene has been identified in most fish species examined. Fish CYP1As, including multiple forms from recent divergence in some genera, have structural and catalytic properties more like CYP1A1, but also have properties that are 1A2-like, consistent with fish CYP1As representing the CYP ancestral to both CYP1A1 and CYP1A2. A number of genes cloned from several species have been classified in the 3A subfamily. Fish CYP3As catalyze steroid 6β-hydroxylase, and have other properties consistent with mammalian 3As. Recently identified CYP4 genes classify to novel subfamilies but apparently are homologues of mammalian CYP4 genes, and may act on similar substrates. The greatest diversity of fish CYP genes is in family 2; there are now six fish CYP2 subfamilies known. Four of these are novel subfamilies, although cladistic analysis suggests distinct relationships to mammalian CYP2 subfamilies. Heterologous expression and characterization of some of these CYP have identified similar functions among genes in different subfamilies. For example, fish CYP2Ns and CYP2Ps are related to mammalian CYP2Js, and CYP2P3 and CYP2J2 have strikingly similar functions as fatty acid epoxygenases and hydroxylases, with nearly identical regio- and enantioselectivity for metabolism of arachidonic acid. In addition to sequence and catalytic similarities, there also are indications that CYP regulation, tissue and cellular localization are similar between fish and mammals. Yet even in cases where orthology is strongly suggested, e.g. CYP1A, there appear to be taxonomic differences in active site structure suggesting potential differences in involvement of CYP1A in toxicity. In contrast to fish, CYP diversity and functions in aquatic invertebrates are poorly known. Investigators have identified novel gene families and subfamilies in crustaceans (CYP2L; CYP45), molluscs (CYP30, CYP10) and sponges (CYP38). CYP4C genes occur in crustaceans, molluscs and echinoderms, and a new subfamily (CYP4Y) in molluscs. The future? There is no doubt that new CYP will continue to be discovered in non-mammalian vertebrates; some (e.g. CYP51) can be predicted confidently. And, there is no doubt that the numbers known in invertebrates will expand greatly. In insects and C. elegans the numbers are very high, and even slime molds have 18 CYP genes. It is virtually certain that CYP genes with unique functions will be discovered. While the knowledge of CYP genes is increasing, knowledge of CYP function and regulation lag well behind. Technical approaches to speed the aquisition of such knowledge are available. The information will be essential to discern the role that CYP play in the disposition and toxicity of xenobiotics, during development as well as in adults. Yet, when such data are in hand, we may have to face the paucity of information on the diversity, function and regulation other enzymes, notably the glutathione S-transferases, glucuronyl transferases and sulfotransferases, in aquatic species. Discerning orthologous relationships among CYP genes, as well as those for phase II enzymes, could highlight gene lineages associated with conserved and endogenous functions. Understanding CYP endogenous functions, as well as their metabolism of xenobiotics, may reveal fully the ways that chemicals cause toxicity. [Support: Sea Grant NA46RG0470-R/P61, EPA R-829890, NIH ES07381].  相似文献   

5.
The Panama Ship Registry has its origins in the year 1917. Nowadays, Panama has the largest vessel registry in the world. The second placed registry in the world ranking is Liberia, which does not have even half the number of Panamanian ships. In this Centennial, the aim of this paper is to analyse the evolution of the Panamanian Registry, the structure of the Panamanian-flagged fleet and the level of compliance with international standards in relation to maritime safety and working conditions. To undertake the analysis, two different qualitative and quantitative approaches are compared and integrated for the evaluation of the Panama Ship Registry: the degree of ratification and enforcement of the Conventions and Recommendations of the International Maritime Organization and International Labour Organization, and the results of Panamanian flagged vessels in inspections carried out within the major Port State Control Memoranda of Understanding. This paper fills a research gap by discussing an approach to the concept of flag of convenience and flag State, Panama is more an international registry, whose role is becoming less important from the points of view of safety or working conditions. The fleet performance evolution has been very positive as evidenced by the data presented in this article regarding Port State Control.  相似文献   

6.
《Marine Policy》1987,11(3):163-183
After a brief historical overview, the author examines the definition of piracy. There are problems with this as definition differs under municipal and international law, and the latter gives rise to two interpretations. Attempts at codifications are described, from the activities of the League of Nations, through the Harvard Research Draft of 1932 to the Geneva Convention on the High Seas in 1958 and the 1982 Law of the Sea Convention. Examples are given of types of piracy, including the seizing of yachts, violence against boat people and political piracy. Possible legal responses to piracy are discussed.  相似文献   

7.
The starting point is an analysis of the evolution of recruitment of crews in the maritime traffic on the global and local scale; a case study in a medium-size port of the European Union, the Port of the Bay of Cadiz, is presented. The evolution of the Open Registries and the phenomenon of the globalization of crewing have been studied from the information provided in the databases of consultants and international bodies. For the case study an analysis has been made of 507 vessels that docked in the port of Cadiz between the years 2002 and 2008. From this analysis, it is concluded both globally and locally that market is evolving rapidly. The question of finding suitable crews is not only economic: sometimes the reasons for these “substitutions” are directly related to the demands in terms of working hours or civilized conditions of accommodation and food. Multiculturality is therefore a general feature of crews today; language is a key determinant of this phenomenon. The implication behind this trend is that the profession of ‘seaman’ in the OECD countries is becoming less attractive from the point of view of personal and even professional life. The human decapitalization of maritime personnel is also a strategic problem in the provision of specialized seamen for tasks of the Maritime Administration and PSC Inspection, together with the progressive aging of the existing crews.  相似文献   

8.
9.
回顾过去展望未来——中国海洋科技发展50年   总被引:17,自引:0,他引:17       下载免费PDF全文
我国是海洋大国,发展海洋事业,对于中华民族的繁荣昌盛和长治久安,对于实现国家“三步走”的宏伟目标,具有重要的战略意义。海洋科技是国家海洋事业发展的强大支撑和不竭动力,开发海洋资源、保护海洋环境、发展海洋经济、维护海洋权益、建设海洋强国,必须依靠海洋科学技术。  相似文献   

10.
11.
The East/Japan Sea is a mid-latitude marginal sea that has undergone dramatic changes during the last 50–60 years. One of the most prominent characteristics of these changes is a rapid decrease in the amount of dissolved oxygen in deep waters. As a consequence of these changes, some investigators have even argued that the East/Japan Sea might become an anoxic sea in the next 200 years. While the causes of these changes are still under investigation, it has been shown that they are mainly due to modifications in the mode of the deep water ventilation system in the East/Japan Sea: a slowdown and complete cessation of bottom water formation accompanied by an enhancement of upper water formation instead. A simple moving-boundary box model (MBBM) was developed in order to analyze and quantify the processes involved in such changes over the last 50–60 years. Using a MBBM, we estimated the levels of several conservative chemical tracers (CFCs, Tritium, SF6, 137Cs) and bioactive tracers (oxygen and phosphate) in the deep water masses of the East/Japan Sea, comparing these with the historical data available, and making predictions for the near future. The model predicts that the East/Japan Sea should remain well-oxygenated, despite recent rapid oxygen decreases in its deep waters, accompanied by such structural changes as a shrinking of its oxygen-depleted deeper waters and an expansion of its oxygen-rich upper waters over the next few decades.  相似文献   

12.
13.
海平面变化是由于太阳、月球等几大行星的天体作用、地球本身作用、生物作用、大气作用和海洋作用及人为因素等叠加作用的结果。所以,海平面变化是许多变数中一个敏感的积分变量,或是各大领域系统耦合效应的一个组合函数。为此,可将上述各个方面的叠加作用和耦合影响称为“天地生耦合效应系统”。并据此建立了相应的日动型、气动型、水动型和地动型等概念模型,旨在研究几大作用之间的多重耦合效应和反馈机制。通过集合变量,采用了时段划分的方法进行定量分析,以确定各变量之间的联系性、有效性和相关性,初步获得地球自转速度是控制海平面变化的动力机制;世界海平面速率为+1.32±0.22mm/a,中国海平面速率为+1.39±0.26mm/a。以C02含量为气候指标,划分出了公元200年以来的八个冷段(冷期)。第Ⅷ冷段极大值大约出现在公元1850年前后,若按冷暖极值距200年计算,则由目前正在发展的暖期,将在公元2050年前后结束,而后开始降温;若按冷暖极值距250年间隔计算,将在公元2100年前后开始降温,彼时,世界海平面将上升+7~11±3.5cm左右(在气候暖期的过程中),且其后海平面将呈下降趋势,与此同时,气候将进入下一个新的冷期(亦即第Ⅸ冷段)。  相似文献   

14.
The use of drifting fish aggregating devices (FADs) has become the dominant practice in tropical tuna purse seine fishing. However, just as FADs can increase fishing efficiency, their use has been associated with several negative ecosystem impacts, and moves are being made to manage the use of FADs. In the evaluation of potential management options it is important to consider how fishers will respond to the introduction of control measures, which first requires an understanding of fishery and fleet dynamics. This paper addresses this need by characterising the past and present use of FADs in the Indian Ocean tropical tuna purse seine fishery. The paper describes historical trends in fishing practices, summarises spatiotemporal patterns in the use of FADs and establishes and attributes variation in FAD fishing strategies within the fleet. It also provides an overview of current FAD management policies in the Indian Ocean and examines the observed effects of existing measures on the behaviour of the purse seine fleet. Using this comprehensive understanding, the potential impact on the purse seine fleet of a number of plausible FAD management options are discussed and inferences are drawn for the future sustainability of tropical tuna purse seine fishing in the Indian Ocean.  相似文献   

15.
The development of an analytical expression to describe the natural variation of global temperature and related climatic variables over periods from a few years or less to over a billion years is shown and seen to match the variation of eustatic sea-level over similar periods. An additional anthropogenic factor to take the greenhouse effect into account is added to this natural climatic variation giving close correlation between the combined natural-plus-anthropogenic model of global temperature variation and its observed history over the past century. This provides grounds for confidence in the subsequent deterministic forecast for the combined model and its sea-level counterpart of, for instance, about 0.7m rise by 2050AD.A tentative physical explanation of the natural climate model is given invoking the possibility that the Universal Gravitational Constant (G) may, in fact, be a variable. In parallel, the anthropogenic climate model is underlined by alluding to a theoretical explanation of the population growth mechanism which largely drives it. The interactive nature of the impact of man on sea-level rise and vice versa is stressed.  相似文献   

16.
The Yellow River cut through Sanmenxia Gorge and discharged into the sea via the North China Plain in 150 ka BP; since then, around 86 000 × 108 t sediment has been transported passing Sanmenxia Gorge. Based on land use and land cover changes in Loess Plateau and other available evidence, an estimate of the Yellow River sediment budget is presented here: about 72% of the sedimentary material was trapped in the North China Plain and the remainder(i.e., 26%) escaped to the sea. At the present stage, 0.2×108 t/a suspended sediment of the Yellow River enter the northern Yellow Sea. The transport pattern is determined mainly by the shelf current system. Annually 0.2×108–0.3×108 t of suspended particles are carried to the East China Sea; the materials are derived mainly from coastal and subaqueous delta erosion associated with the abandoned Yellow River on the Jiangsu coast. Since 1972, the lower Yellow River started to have a situation of continuous no-flow. During 1996–2000, the annual water flow and sediment discharge are only 19%, as compared with normal years(i.e., average for 1950–1979). In response to global warming and increase of water diversion from the Yellow River for industrial and urban use, the sediment flux of the Yellow River to the sea will most likely remain small in the next two to three decades.  相似文献   

17.
《Marine Policy》1999,23(4-5):375-396
This paper reviews experiences with voluntary and statutory marine nature reserves in Britain, and considers what lessons can be applied to the designation of 39 marine special areas of conservation that are currently being pursued under the Habitats Directive. It is argued that these experiences indicate that cautious approaches which provide for the meaningful participation of stakeholders can be successful in both achieving nature conservation objectives and promoting cooperation, and that a reliance on statutory powers can exacerbate conflicts and undermine the potential for cooperation. It is concluded that there is a need to put concepts into practice by shifting from the consultation interpretation paradigm to one based on meaningful stakeholder participation and joint planning if the major opportunity provided by the Habitats Directive is not to be jeopardised.  相似文献   

18.
19.
Comprehensive, aggregate nutrient budgets were established for two compartments of the North Sea, the shallow coastal and deeper open regions, and for three different periods, representing pre-eutrophication (∼1950), eutrophication (∼1990) and contemporary (∼2000) phases. The aim was to quantify the major budget components, to identify their sources of variability, to specify the anthropogenic components, and to draw implications for past and future policy. For all three periods, open North Sea budgets were dominated (75%) by fluxes from and to the North-East Atlantic; sediment exchange was of secondary importance (18%). For the coastal North Sea, fluxes during the eutrophication period were dominated by sediment exchange (49% of all inputs), followed by exchange with the open sea (21%), and anthropogenic inputs (19%). Between 1950 and 1990, N-loading of coastal waters increased by a factor of 1.62 and P-loading by 1.45. These loads declined after 1990. Interannual variability in Atlantic inflow was found to correspond to a variability of 11% in nutrient load to the open North Sea. Area-specific external loads of both the open and coastal North Sea were below Vollenweider-type critical loads when expressed relative to depth and flushing. External area-specific load of the coastal North Sea has declined since 1990 from 1.8 to about 1.4 g P m−2 y−1 in 2000, which is close to the estimate of 1.3 for 1950. N-load declined less, leading to an increase in N/P ratio.  相似文献   

20.
The integration of the South African fisheries into the global economy has operated as a powerful constraint on post-apartheid fisheries reform. The shedding of South Africa's international pariah status and currency depreciation enhanced access to and competitiveness on global markets, sparking a demersal-led export boom, which has favoured incumbent producers. Increased exports have also allowed the post-apartheid state and nascent black capital to maximise their returns from the fisheries through cost recovery and share purchases. The protection and promotion of the fisheries’ “international competitiveness”, inter alia sought through “sustainable fishery” certification of the hake industry with the Maritime Stewardship Council (MSC), has in turn provided a cover-all for the refusal of populist redistribution demands and special treatment for black small capital.  相似文献   

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