Sea Cucumber Moratorium and Livelihood Diversity in Papua New Guinea

Livelihood diversity factors such as flexibility within fisheries, geographical mobility, reallocation of fishing effort into the broader economy, and the non-material benefits that fisheries provide are important areas of research in marine policy. We use two small-scale fisheries related socio-economic surveys of communities in the Tigak Islands of Papua New Guinea. The first conducted 5 years before a ban on the harvesting of sea cucumbers was imposed and the second from the present day, 5 years after the initiation of the ban—with the objectives of exploring changes in household fishing strategies (types and numbers of species targeted) and to identify any important socioeconomic factors that help explain those changes. Fishing's contribution to total household income has increased significantly (p = 0.019) up from 61% in 2004 to 73% in 2014 with the percentage of female residents living in a household now positively and significantly (p = 0.018) associated with fishing income. The average number of species categories targeted per household increased insignificantly while households with more women are significantly (p = 0.018) less likely to target more species than households with more men. Moreover, customary management practices contribute to this difference. Together, these results show that households are not worse off financially 5 years after the ban on sea cucumber harvesting and that gendered seascape use has implications for the role of livelihood diversity as a marine policy tool.     

The Impact of Recreation on Barrier Islands: A Case Study on Masonboro Island

Since 1992, coastal researchers at the University of North Carolina at Wilmington have been documenting the impacts of human recreational use on Masonboro Island, a component of the North Carolina National Estuarine Research Reserve, and the subsequent natural processes that mitigate these impacts. Both short-term and long-term natural mitigational processes were identified. The effects of these processes were found to be much more rapid than similar impacts on typical terrestrial settings. However, careful examination of the data suggests that both physical location of the impact site and natural variability of weather patterns and events play a role. Management implications of these findings are proposed.     

Simulated responses of the Gulf of Mexico hypoxia to variations in climate and anthropogenic nutrient loading

A mathematical model was used to simulate monthly responses of the Gulf of Mexico hypoxia to variations in climate and anthropogenic nutrient loading over a 45-year period. We examined six hypothetical future scenarios that are based on observed and projected changes in the Mississippi River discharge, Mississippi River nitrate concentrations, and ambient water temperatures. In particular, we investigated the implications of a 30% decrease in the Mississippi River nitrogen flux, which was recently proposed by the Mississippi River Watershed/Gulf of Mexico Hypoxia Task Force as a measure to reduce the size of the hypoxic zone. Model simulations suggest that the frequency of hypoxia in the northern Gulf of Mexico is highly sensitive to variations in riverine nitrate flux, but also to variations in freshwater discharge and ambient water temperatures. A 30% decrease in the Mississippi River nitrate flux, for example, would reduce the frequency of hypoxia by 37%. Nevertheless, a 20% increase the Mississippi River discharge, which may occur under some climate change scenarios, would produce an increase in the frequency of hypoxia of the same magnitude. Thus, if the potential climatic variations are taken into account, a 30% decrease in the nitrogen flux of the Mississippi River may not be sufficient to accomplish the proposed hypoxia management goal.     

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提出了一个在有高速公路和城市干道的组合路网中设置可变信息标志(CMS)组位置的最优化模型．与文献中现有的模型相比较，本文的模型有效地达到了实际规模道路网络计算复杂性问题和确保求解模型的质量之间很好的平衡． 本模型具有三个不同的特征：(1)认为在路网中设置安装可变信息标志(CMS)系统是一个必须同时考虑现在和未来需要和利益的典型的规划问题；(2)评估由于在路网中设置了可变信息标志(CMS)系统而带来的交通效益是通过具有不同交通分布型态的多个时段来完成的；(3)考虑了在不同的路段上和时段内交通事件的特征本质上是变化的因素．本文还进行了敏感性分析，用以检验在各种不同的交通输入参数中，如交通需求、交通事件特征值、以及驾驶员交通行为的不确定性对可变信息标志系统(CMS)在路网中的最优设置的潜在影响．最后，本模型应用于加拿大多伦多的401高速公路和辅道组成的混合道路系统，并且对CMS系统设置结果进行了检验．     

Evaluating seaport policy alternatives: a simulation study of terminal leasing policy and system performance

The competitive characteristics of the North American seaport industry have, in theory, been causally linked to excess investment and low terminal throughput productivity. This paper empirically examines the link between seaport authority container terminal leasing policy and throughput productivity. Recent advances in inventory theory applied to service industries suggest the pooling of demand uncertainty can yield lower costs without sacrificing customer service. This concept is applied to a container seaport using simulation. The effort compares key output measures from a realistic base case model of the seaport to those generated by an alternative terminal leasing policy. It is shown that the pooling of demand in a common-user seaport reduces total vessel time in port by 17.1% with no reduction in TEU throughput. Throughput productivity is improved for the highest capacity terminals, while lower capacity terminals are made available for additional users or alternative uses.     

Travel to work and household responsibility: new evidence

A persistent empirical finding in the research on travel patterns is that women tend to engage in shorter work commutes than men. Research evaluating the degree to which this gender differential in commuting may be explained by the division of labor in the household has produced decidedly mixed findings. This paper presents a critical review of the methods and results of recent research on the gender differential in commuting along with the associated implications for the household responsibility hypothesis (HRH). While all of the articles reviewed are informative and unique, not all conclusions are well supported. The paper then tests the HRH using the 1990 NPTS travel data. The new evidence confirms that women continue to exhibit shorter commute times and distances than men and provides support for the HRH. The paper concludes with a summary of findings and recommendations for further research.     

Modelling the hydrodynamics and ecosystem of the North-West European continental shelf for operational oceanography

This paper outlines an approach to complex spatio-temporal marine ecosystem modelling as applied to the North Western European Continental Shelf. The model presented here combines an eddy-permitting (approximately 6 km horizontal resolution) baroclinic model, the Proudman Oceanographic Laboratory Coastal Ocean Modelling System (POLCOMS), with the European Regional Seas Ecosystem Model (ERSEM). This has been run within an operational framework using operationally available high resolution atmospheric and lateral boundary forcing, allowing hindcast and near-real time nowcast simulations to be performed. The modelled surface temperature and chlorophyll distributions are presented, and interannual variations discussed. Validation of both the physical and ecosystem submodels show the system to be effective, whilst highlighting areas where improvements in the system can be made. Distinct regional differences in predictive skill are shown. The system presented is ready for operational implementation to provide products and services for use both scientifically and in coastal zone and shelf seas management activities. A programme of work to update the system is already in place.     

Development of a behaviorally induced system optimal travel demand management system

The basic design concept of most advanced traveler information systems (ATIS) is to present generic information to travelers, leaving travelers to react to the information in their own way. This “passive” way of managing traffic by providing generic traffic information makes it difficult to predict the outcome and may even incur an adverse effect, such as overreaction (also referred to as the herding effect). Active traffic and demand management (ATDM) is another approach that has received continual attention from both academic research and real-world practice, aiming to effectively influence people's travel demand, provide more travel options, coordinate between travelers, and reduce the need for travel. The research discussed in this article deals with how to provide users with a travel option that aims to minimize the marginal system impact that results from this routing. The goal of this research is to take better advantage of the available real-time traffic information provided by ATIS, to further improve the system level traffic condition from User Equilibrium (UE), or a real-world traffic system that is worse than UE, toward System Optimal (SO), and avoid passively managing traffic. A behaviorally induced, system optimal travel demand management model is presented to achieve this goal through incremental routing. Both analytical derivation and numerical analysis have been conducted on Tucson network in Arizona, as well as on the Capital Area Metropolitan Planning Organization (CAMPO) network in Austin, TX. The outcomes of both studies show that our proposed modeling framework is promising for improving network traffic conditions toward SO, and results in substantial economic savings.     

Evaluating seaport policy alternatives: a simulation study of terminal leasing policy and system performance

The competitive characteristics of the North American seaport industry have, in theory, been causally linked to excess investment and low terminal throughput productivity. This paper empirically examines the link between seaport authority container terminal leasing policy and throughput productivity. Recent advances in inventory theory applied to service industries suggest the pooling of demand uncertainty can yield lower costs without sacrificing customer service. This concept is applied to a container seaport using simulation. The effort compares key output measures from a realistic base case model of the seaport to those generated by an alternative terminal leasing policy. It is shown that the pooling of demand in a common-user seaport reduces total vessel time in port by 17.1% with no reduction in TEU throughput. Throughput productivity is improved for the highest capacity terminals, while lower capacity terminals are made available for additional users or alternative uses.     

Developing management guidelines for oil and gas activities: The louisiana experience

Abstract

Preliminary management guidelines have been derived for oil and gas activities in coastal Louisiana. Derivation of these guidelines was done in terms of the natural function of the coastal ecosystem; this means that all economic activities should be designed to complement natural function as much as possible. The guidelines range in scope from very specific, almost performance standards, to very general admonitions. For example, we have suggested that spoil banks, produced as a result of dredging, should not be higher than the height of the daily tide or roughly 15 cm in coastal Louisiana, and at the other extreme, we have suggested that all dredging should be done with great care during wildlife migrations, spawning, and nesting times.