Biochemical composition of marine sediment from the eastern Weddell Sea (Antarctica): High nutritive value in a high benthic-biomass environment

Within the SCAR's international EASIZ programme, as part of the benthic–pelagic coupling experiment, grain size and organic matter contents in marine surface sediment were measured. Samples were taken during the austral autumn of 2000 from 3 regions in the eastern Weddell Sea: Kapp Norvegia, Four Seasons Bank, and Austasen.In general, sediments were fine sand with a grain size fraction < 200 μm representing more than 40% of the total weight. The sediments from Four Seasons Bank (64 to 107 m depth) were coarser than those from Austasen and Kapp Norvegia (209 to 480 m depth), presumably due to winnowing of fine sediment at shallow depths. Organic carbon (OC) content ranged from 0.25% to 1.2% and constituted 10% to 97% of the total carbon. The samples from Kapp Norvegia presented the highest OC values. Overall, protein (PRT), lipid (LPD), and carbohydrate (CHO) contents were similar to those in sediment from cold regions (e.g., the North Atlantic and the Ross Sea) but higher than those in sediment from other Antarctic and more septentrional regions (e.g., the Ross Sea and the Mediterranean). The difference within the Antarctic is explained through the local conditions in Terra Nova Bay and Kapp Norvegia. In the Antarctic, PRT and LPD carbon were the main contributors to the biopolymeric carbon (BPC). In the eastern Weddell Sea shelf, the BPC accounted for more than 90% of the OC in most of the samples. More than 82% of the total PRT, LPD, and CHO were present in the fraction < 200 μm. This work remarks the existence of sediments with a high nutritional value persistent several weeks after the spring–summer pulse of fresh organic matter. It is also highlighted the high potential availability of these sediments (due to its grain size) for the benthic communities inhabiting this high-latitude continental shelf.     

Eddies around Madagascar — The retroflection re-considered

The Agulhas Current with its retroflection and attendant eddy-shedding is the cause of some of the greatest mesoscale variability in the ocean. This paper considers the area to the south and east of Madagascar, which provides some of the source waters of the Agulhas Current, and examines the propagating sea surface height signals in altimetry and output from a numerical model, OCCAM. Both show bands of variability along the axis of the East Madagascar Current (EMC) and along a zonal band near 25°S. Sequences of images plus associated temperature data suggest that a number of westward-propagating eddies are present in this zonal band. The paper then focuses on the region to the south of the island, where ocean colour and infra-red imagery are evocative of an East Madagascar Retroflection. The synthesis of data analysed in this paper, however, shows that remotely observed features in this area can be explained by anticyclonic eddies moving westward through the region, and this explanation is consistent with numerical model output and the trajectories of drifting buoys.     

Environmental changes in the western Black Sea related to anthropogenic and natural conditions

The Black Sea northwestern shelf (NWS) ecosystem has been subjected to the strongest anthropogenic pressure of the entire Black Sea as about 80% of the freshwater runoff is discharged there.This paper presents a review of the global environmental changes related mainly to increased eutrophication in the western Black Sea basin.A case study (CoMSBlack 92a cruise) attempts to highlight the interaction of some natural and anthropogenic factors responsible for specific chemical and biological features in the western Black Sea environment. The significance of processes located near the Danube river mouth, which, due to their relatively small space scale, have not been recognized before, is clarified. Hydrological processess of specific importance to the distribution and transformation of antropogenic inputs are river plume dynamics, coastal upwelling and mixing and downwelling over the shelf break and slope in this part of the basin. A layer of low hydrological variability (“conservative layer”) appears to be a natural feature of the area, hypothesized to precondition specific biological and chemical processes there.The results suggest that the interplay between the Danube anthropogenic nutrient load with the natural hydrological fronts and gradients provides opportunities for enhanced biological activity thus contributing to the global environmental changes in the Black Sea NWS.     

Synergies between Adjacent Beach-Nourishing Communities in a Morpho-Economic Coupled Coastline Model

Beach “nourishment” consists of placing sand on an eroding beach. The widened beach provides increased storm protection to adjacent structures and improved recreational benefits, but is most often transient, requiring on-going, repeated nourishment episodes. Numerical models of beach nourishment typically address such questions as how long a widened beach will last; economic models compare the benefits and costs of preserving a stretch of beach without regard to its geomorphic evolution. Neither have addressed the physical nor economic interactions between adjacent nourishing communities. Here, we couple a numerical model of coastline evolution and a cost-benefit model of beach nourishment, allowing adjacent communities to make dynamic nourishment decisions. Beach nourishment benefits adjacent communities both “updrift” and “downdrift.” The total amount of money spent on nourishment activities can decrease by as much as 25% when adjacent communities both conduct on-going nourishment projects, as opposed to the case where each community nourishes in isolation.     

Protecting Rhode Island's coastal salt ponds: An economic assessment of downzoning

Abstract

In southern Rhode Island, there is growing concern that housing and recreational demands will soon overwhelm the capacity of the coastal salt ponds to absorb wastes, produce seafood, and maintain scenic qualities. As a result, coastal towns have been studying the feasibility of using land controls such as downzoning to protect these coastal amenities. The paper presents an economic analysis of the downzoning program proposed in the town of South Kingstown. Hedonic price and contingent valuation methods are used to value coastal amenities. The estimated net present value of “swimmable” water is shown to be $3.1 million.     

The problems of hydrocarbon extraction

The problems associated with hydrocarbon extraction in the EEZ are discussed under the headings of resources and environment, technology and the industrial structure, government management, decision-making, and policy formulation. Policy areas identified include boundary delimitation relative to resources, environment and technology, co-ordination and decision-making machinery, relationships with UK and EEC energy policies, and regional planning of the sea and coastal areas used by the off-shore industry.     

Collaborative Management of Natural Resources in San Diego Bay

This article presents the results of a three-year effort at applying information technology to the problem of collaborative natural resource management in San Diego Bay. As such, it represents an approach to integrated coastal zone management (ICZM). This effort resulted from a collaboration between the San Diego Supercomputer Center at the University of California, San Diego and the San Diego Bay Interagency Water Quality Panel for the purpose of (1) developing an environmental data repository to facilitate the acquisition and sharing of data and (2) the development of a visual model of the bay in support of the development of a comprehensive, coordinated management plan for San Diego Bay. It was determined from this study that information technology is an important and key component to ICZM but that sociopolitical factors may override the benefits of decision-support systems and should be considered at the outset of any project of this kind.     

Transport infrastructure provision and operations: Why should governments choose private–public partnership?

Recent transport sector liberalisation, as well as global economic crisis, is favouring the implementation of transport infrastructure projects through Public–Private Partnerships (PPP). However, there is a debate as to whether PPP schemes are a better option than conventional procurement. To this end, an evaluation framework is proposed, to assess which of these two alternative schemes for transport projects financing is preferable for the public. The proposed framework is complimentary to the Value for Money (VfM) approach and is based on a Multi Criteria Analysis (MCA). The first step is the estimation of the Public Sector Comparator (PSC) for the case of conventional procurement, dealing with construction, maintenance and operation costs revenues, as well as any costs associated with risks undertaken by the public. As for the PPP case, it includes any payments by the public sector and related risks costs. The MCA is then applied only if the PPP is found preferable for the public sector. The latter considers additional impacts, including among others the social attributes of a particular scheme, job creation, environmental impacts and safety and security aspects. The proposed framework was applied to a pilot Bus Rapid Transit (BRT) corridor infrastructure project in the city of Indore, India, in order to demonstrate its validity. The framework and its application could provide useful guidance when considering PPP for a transport project, since it demonstrates in a transparent way the society's attitude towards this project, something that is critical to its acceptance.     

Determinants of motor vehicle crash fatalities using Bayesian model selection methods

Motor vehicle crashes continue to result in large numbers of fatalities each year and represent the leading cause of death for young persons. In 2006, for example, there were over 42,700 fatalities associated with these crashes. Understanding the causes of these crashes and methods to reduce them continues to be of great interest to economists, public health officials, and policy makers. We present in this paper statistical models using a rich set of panel data covering the period 1980 to 2007 by state and the District of Columbia. Our choice of variables is based on an extensive literature highlighting the importance of policy, safety, demographic, and economic determinants of fatality rates.