Simple Identification of Some Coastal Marine Habitats by Modeling with Sea-Chart Data

A simple numerical model was applied to distinguish permanently oxygenated marine sill basins from periodically anoxic basins in Nordland County, northern Norway. Input data are sill depth, width of the tidal channel, sea surface area, and tidal range. The model produces a Topography Tidal Factor (TTF) that seems to be an adequate index correlating with empirical field data when sills have saddle depths <30 m. The depth of the pycnocline, and the oxygen concentration of the basin water increases logarithmically with the calculated TTF value toward an asymptotic level. At TTF ≥0.02 basins are mostly well-oxygenated and have a permanent fauna of epibenthic and hyperbenthic animals. Basins with TTF <0.02 may become anoxic each autumn, which permanently prevents establishment of communities with multi-annual sessile benthos. Low oxygen concentration may also cause seasonal variation in the occurrence of motile species. In tidal channels, the abundance of bivalves and fish, as well as the biodiversity in general, probably increases with TTF. The applied method may be universally valid in regions shaped by glacial erosion but needs to be further developed by more detailed studies.     

A most convenient flag--the basis for the expansion of the Singapore fleet, 1969-82

Singapore's brief stint as a fully-fledged Flag of Convenience from the late 1960s to the late 1970s facilitated the strong expansion of the country's merchant marine. This article outlines the basis for the introduction of Flag of Convenience-facilities in Singapore, analyses the transformation of the fleet in the period 1969–82 and examines the tightening of the registration requirements from the late 1970s onwards. Certain characteristics of the Singapore fleet and the pragmatism of the authorities in establishing and disbanding the open registry distinguish the Singapore registry from some of the other important Flags of Convenience.     

政府支持下的瑞典铁路实施网运分离

阐述了瑞典铁路在重组过程中政府的支持力度，以及政府支持下运输政策的变化、BV所发挥的作用和重组的最新进展，分析了网运分离的优势。     

A most convenient flag--the basis for the expansion of the Singapore fleet, 1969-82

Singapore's brief stint as a fully-fledged Flag of Convenience from the late 1960s to the late 1970s facilitated the strong expansion of the country's merchant marine. This article outlines the basis for the introduction of Flag of Convenience-facilities in Singapore, analyses the transformation of the fleet in the period 1969-82 and examines the tightening of the registration requirements from the late 1970s onwards. Certain characteristics of the Singapore fleet and the pragmatism of the authorities in establishing and disbanding the open registry distinguish the Singapore registry from some of the other important Flags of Convenience.     

Transverse strength analysis of catamarans

Stresses and deformations relevant for transverse strength analysis are calculated for a 60 m catamaran by a compartment model and are compared with corresponding results from a global model. It is found that the flexibility of the partial bulkheads typical for a twin-hull Ro/Ro-vessel is so large that the interaction with the surrounding structure has to be accounted for. If springs are applied, the results are sensitive to the spring stiffness. A web frame model that does not include any bulkheads, gives large errors and is not recommended.     

A conceptual model of the trophodynamical response to river discharge in a large marine ecosystem

Year-class strength in North-East Arctic cod (Gadus morhua), which inhabit the Barents Sea, and commercial landings of juveniles from this population, have been positively correlated with Norwegian meltwater discharge one and three years in advance, respectively. A conceptual model is developed, by empirical data used to investigate how the freshwater signal may be transmitted with time and in space through the food-web. It assumes that interannual variation in discharged volume of meltwater during summer forces planktonic primary production in neritic fronts. The strength of this impulse is transmitted from one organismic system to another, along the north Norwegian shelf, being advected by Calanus finmarchicus, a herbivorous copepod. The population system of this copepod interacts with the survival and growth of juvenile NE Arctic cod, and causes the cod stock size to fluctuate with the strength of the signal. By migration and advection within their respective population systems, NE Arctic cod and C. finmarchicus possibly transmit the freshwater signal on extensive time and space scales, from the Norwegian shelf to distant parts of the Arctic Mediterranean Ecocystem that contains both population systems. Continued empirical research and numerical modelling is needed to develop this theory.     

Future cost scenarios for reduction of ship CO2 emissions

International shipping is a significant contributor to Global Greenhouse Gas (GHG) emissions, responsible for approximately 3% of global CO₂ emissions. The International Maritime Organization is currently working to establish GHG regulations for international shipping and a cost effectiveness approach has been suggested to determine the required emission reductions from shipping. To achieve emission reductions in a cost effective manner, this study has assessed the cost and reduction potential for present and future abatement measures based on new and unpublished data. The model used captures the world fleet up to 2030, and the analysis includes 25 separate measures. A new integrated modelling approach has been used combining fleet projections with activity-based CO₂ emission modelling and projected development of measures for CO₂ emission reduction. The world fleet projections up to 2030 are constructed using a fleet growth model that takes into account assumed ship type specific scrapping and new building rates. A baseline trajectory for CO₂ emission is then established. The reduction potential from the baseline trajectory and the associated marginal cost levels are calculated for 25 different emission reduction measures. The results are given as marginal abatement cost curves, and as future cost scenarios for reduction of world fleet CO₂ emissions. The results show that a scenario in which CO₂ emissions are reduced by 33% from baseline in 2030 is achievable at a marginal cost of USD 0 per tonne reduced. At this cost level, emission in 2010 can be reduced by 19% and by 24% in 2020. A scenario with 49% reduction from baseline in 2030 can be achieved at a marginal cost of USD 100 per tonne (27% in 2010 and 35% in 2020). Furthermore, it is evident that further increasing the cost level beyond USD 100 per tonne yield very little in terms of further emission reduction. The results also indicate that stabilising fleet emissions at current levels is obtainable at moderate costs, compensating for fleet growth up to 2030. However, significant reductions beyond current levels seem difficult to achieve. Marginal abatement costs for the major ship types are also calculated, and the results are shown to be relatively homogenous for all major ship types. The presented data and methodology could be very useful for assisting the industry and policymakers in selecting cost effective solutions for reducing GHG emissions from the world fleet.