1,165 research outputs found
Synopses of research on shrimps: 1. The common shrimp species of Sierra Leone's coastal waters: their distribution, abundance and size composition
The authors present quantitative information on the shrimp resources of Sierra Leone waters. Four of the nine species present have been studied, of which Paenaeus duorarum notialis is dominant in the fishery. Synoptic surveys were undertaken in June 1977, and March 1978, to determine the abundance of the shrimp stock on the inshore shelf. The temperature-salinity-depth curves for the fishing ground show the existence of three water masses. The majority of fish caught were sciaenids, with some sparids also being taken. Detailed discussion of distribution and abundance of individual species of shrimp is given. The surveys have shown that the Banana Islands are the most productive shrimp grounds in the country, and the authors believe that they can support a viable shrimp industry for several years to come at present rates of exploitatio
Environmental issues in economic partnership agreements: Implications for developing countries
This issue paper, titled 'Environmental Issues in Economic Partnership Agreements: Implications for Developing Countries', and written by Mrs. Beatrice Dove-Edwin, is a contribution to that process. The paper exhaustively reviews all rules related to trade and environment in several of the already signed EPAs. The aim of the paper is to enable ACP countries to understand how trade policy related to the environment has been introduced in EPAs, and how those policies might impact sustainable development in ACP countries. The paper starts by presenting the current European approach on trade and environment in those agreements. More specifically, it addresses the current state of negotiations, analyses precise proposals made, and explores some of the implications of introducing environmental issues in the EPAs ..
Bathymetric terrain model of the Atlantic margin for marine geological investigations.
Bathymetric terrain models of seafloor morphology are an important component of marine geological investigations. Advances in acquisition and processing technologies of bathymetric data have facilitated the creation of high-resolution bathymetric surfaces that approach the resolution of similar surfaces available for onshore investigations. These bathymetric terrain models provide a detailed representation of the Earth’s subaqueous surface and, when combined with other geophysical and geological datasets, allow for interpretation of modern and ancient geological processes. The purpose of the bathymetric terrain model presented in this report is to provide a high-quality bathymetric surface of the Atlantic margin of the United States that can be used to augment current and future marine geological investigations. The input data for this bathymetric terrain model, covering almost 305,000 square kilometers, were acquired by several sources, including the U.S. Geological Survey, the National Oceanic and Atmospheric Administration National Geophysical Data Center and the Ocean Exploration Program, the University of New Hampshire, and the Woods Hole Oceanographic Institution. These data have been edited using hydrographic data processing software to maximize the quality, usability, and cartographic presentation of the combined terrain model
Institutional change in the international governance of agriculture: a revised account
The place of agriculture in the General Agreement on Tariffs and Trade (GATT) prior to 1986 is usually described in terms of either exclusion or exemption from general trading rules. This paper reevaluates the ‘exemption’ argument and its corollary that the Uruguay Round Agreement on Agriculture (AoA) represented a punctuated equilibrium in the governance of agriculture. Instead it traces the dynamics of institutional change through the history of the GATT/WTO, distinguishing between multilateral trading rounds and the framework of trade rules as separate but linked contexts for addressing agricultural trade matters; and further disaggregating the latter into broad principles and specific rules. It is argued that the broad principles lacked detail but, paradoxically, initially this facilitated an approach to dispute settlement based on conciliation. Subsequent trade tensions exposed an inability to make definitive legal decisions on the compatibility of specific national rules with broad GATT principles. The AoA is rooted in these institutional antecedents, but claims of the legalization of the trade regime are belied by a continued reliance on political flexibility and bargaining
Geomorphic characterization of the U.S. Atlantic continental margin
This paper is not subject to U.S. copyright. The definitive version was published in Marine Geology 338 (2013): 46–63, doi:10.1016/j.margeo.2012.12.008.The increasing volume of multibeam bathymetry data collected along continental margins is providing new opportunities to study the feedbacks between sedimentary and oceanographic processes and seafloor morphology. Attempts to develop simple guidelines that describe the relationships between form and process often overlook the importance of inherited physiography in slope depositional systems. Here, we use multibeam bathymetry data and seismic reflection profiles spanning the U.S. Atlantic outer continental shelf, slope and rise from Cape Hatteras to New England to quantify the broad-scale, across-margin morphological variation. Morphometric analyses suggest the margin can be divided into four basic categories that roughly align with Quaternary sedimentary provinces. Within each category, Quaternary sedimentary processes exerted heavy modification of submarine canyons, landslide complexes and the broad-scale morphology of the continental rise, but they appear to have preserved much of the pre-Quaternary, across-margin shape of the continental slope. Without detailed constraints on the substrate structure, first-order morphological categorization the U.S. Atlantic margin does not provide a reliable framework for predicting relationships between form and process.This work was funded by the USGS Mendenhall Postdoctoral
Fellowship Program and the U.S. Nuclear Regulatory Commission
Seroprevalence of cytomegalovirus, Epstein Barr virus and varicella zoster virus among pregnant women in Bradford: a cohort study.
OBJECTIVE: To estimate the seroprevalence of cytomegalovirus (CMV), Epstein Barr virus (EBV) and varicella zoster virus (VZV) among pregnant women in Bradford by ethnic group and country of birth. METHODS: A stratified random sample of 949 pregnant women enrolled in the Born in Bradford birth cohort was selected to ensure sufficient numbers of White UK born women, Asian UK born women and Asian women born in Asia. Serum samples taken at 24-28 weeks' gestation were tested for CMV IgG, EBV IgG and VZV IgG. Each woman completed a questionnaire which included socio-demographic information. RESULTS: CMV seroprevalence was 49% among the White British women, 89% among South Asian UK born women and 98% among South Asian women born in South Asia. These differences remained after adjusting for socio-demographic factors. In contrast, VZV seroprevalence was 95% among women born in the UK but significantly lower at 90% among South Asian women born in Asia. EBV seroprevalence was 94% overall and did not vary by ethnic group/country of birth. CONCLUSIONS: Although about half of White British women are at risk of primary CMV infection in pregnancy and the associated increased risk of congenital infection, most congenital CMV infections are likely to be in children born to South Asian women with non-primary infection during pregnancy. South Asian women born in South Asia are at risk of VZV infection during pregnancy which could produce congenital varicella syndrome or perinatal chickenpox. Differences in CMV and VZV seroprevalence by ethnic group and country of birth must be taken into account when universal immunisation against these viruses is contemplated
Geomorphic process fingerprints in submarine canyons
This paper is not subject to U.S. copyright. The definitive version was published in Marine Geology 337 (2013): 53-66, doi:10.1016/j.margeo.2013.01.005.Submarine canyons are common features of continental margins worldwide. They are conduits that funnel vast quantities of sediment from the continents to the deep sea. Though it is known that submarine canyons form primarily from erosion induced by submarine sediment flows, we currently lack quantitative, empirically based expressions that describe the morphology of submarine canyon networks. Multibeam bathymetry data along the entire passive US Atlantic margin (USAM) and along the active central California margin near Monterey Bay provide an opportunity to examine the fine-scale morphology of 171 slope-sourced canyons. Log–log regression analyses of canyon thalweg gradient (S) versus up-canyon catchment area (A) are used to examine linkages between morphological domains and the generation and evolution of submarine sediment flows. For example, canyon reaches of the upper continental slope are characterized by steep, linear and/or convex longitudinal profiles, whereas reaches farther down canyon have distinctly concave longitudinal profiles. The transition between these geomorphic domains is inferred to represent the downslope transformation of debris flows into erosive, canyon-flushing turbidity flows. Over geologic timescales this process appears to leave behind a predictable geomorphic fingerprint that is dependent on the catchment area of the canyon head. Catchment area, in turn, may be a proxy for the volume of sediment released during geomorphically significant failures along the upper continental slope. Focused studies of slope-sourced submarine canyons may provide new insights into the relationships between fine-scale canyon morphology and down-canyon changes in sediment flow dynamics
Making Decisions on the Demolition or Refurbishment of Social Housing
This policy briefing summarises the main factors involved when deciding whether to refurbish or demolish social housing, including environmental and economic costs and benefits. Such decisions will involve trade-offs between different objectives and values. The briefing discusses: • evaluating the economic case for refurbishment, including impacts on communities and residents; • the energy and carbon implications of demolition compared to refurbishment; • issues around water and waste; and • social factors in housing and regeneration, including health and community participation
Demersal fish assemblages on seamounts and other rugged features in the northeastern Caribbean
© The Author(s), 2017. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 123 (2017): 90–104, doi:10.1016/j.dsr.2017.03.009.Recent investigations of demersal fish communities in deepwater (>50 m) habitats have considerably increased our knowledge of the factors that influence the assemblage structure of fishes across mesophotic to deep-sea depths. While different habitat types influence deepwater fish distribution, whether different types of rugged seafloor features provide functionally equivalent habitat for fishes is poorly understood. In the northeastern Caribbean, different types of rugged features (e.g., seamounts, banks, canyons) punctuate insular margins, and thus create a remarkable setting in which to compare demersal fish communities across various features. Concurrently, several water masses are vertically layered in the water column, creating strong stratification layers corresponding to specific abiotic conditions. In this study, we examined differences among fish assemblages across different features (e.g., seamount, canyon, bank/ridge) and water masses at depths ranging from 98 to 4060 m in the northeastern Caribbean. We conducted 26 remotely operated vehicle dives across 18 sites, identifying 156 species of which 42% of had not been previously recorded from particular depths or localities in the region. While rarefaction curves indicated fewer species at seamounts than at other features in the NE Caribbean, assemblage structure was similar among the different types of features. Thus, similar to seamount studies in other regions, seamounts in the Anegada Passage do not harbor distinct communities from other types of rugged features. Species assemblages, however, differed among depths, with zonation generally corresponding to water mass boundaries in the region. High species turnover occurred at depths <1200 m, and may be driven by changes in water mass characteristics including temperature (4.8–24.4 °C) and dissolved oxygen (2.2–9.5 mg per l). Our study suggests the importance of water masses in influencing community structure of benthic fauna, while considerably adding to the knowledge of mesophotic and deep-sea fish biogeography.Funding was provided by NOAA-OER for the 2014 E/V Nautilus cruise and by the USGS Environments and Hazards Program and Ocean Exploration Trust for the 2013 E/V Nautilus 807 cruise.2019-03-1
Assessment of tsunami hazard to the U.S. Atlantic margin
This paper is not subject to U.S. copyright. The definitive version was published in Marine Geology 353 (2014): 31-54, doi:10.1016/j.margeo.2014.02.011.Tsunami hazard is a very low-probability, but potentially high-risk natural hazard, posing unique challenges to scientists and policy makers trying to mitigate its impacts. These challenges are illustrated in this assessment of tsunami hazard to the U.S. Atlantic margin. Seismic activity along the U.S. Atlantic margin in general is low, and confirmed paleo-tsunami deposits have not yet been found, suggesting a very low rate of hazard. However, the devastating 1929 Grand Banks tsunami along the Atlantic margin of Canada shows that these events continue to occur. Densely populated areas, extensive industrial and port facilities, and the presence of ten nuclear power plants along the coast, make this region highly vulnerable to flooding by tsunamis and therefore even low-probability events need to be evaluated.
We can presently draw several tentative conclusions regarding tsunami hazard to the U.S. Atlantic coast. Landslide tsunamis likely constitute the biggest tsunami hazard to the coast. Only a small number of landslides have so far been dated and they are generally older than 10,000 years. The geographical distribution of landslides along the margin is expected to be uneven and to depend on the distribution of seismic activity along the margin and on the geographical distribution of Pleistocene sediment. We do not see evidence that gas hydrate dissociation contributes to the generation of landslides along the U.S. Atlantic margin. Analysis of landslide statistics along the fluvial and glacial portions of the margin indicate that most of the landslides are translational, were probably initiated by seismic acceleration, and failed as aggregate slope failures. How tsunamis are generated from aggregate landslides remains however, unclear. Estimates of the recurrence interval of earthquakes along the continental slope may provide maximum estimates for the recurrence interval of landslide along the margin.
Tsunamis caused by atmospheric disturbances and by coastal earthquakes may be more frequent than those generated by landslides, but their amplitudes are probably smaller. Among the possible far-field earthquake sources, only earthquakes located within the Gulf of Cadiz or west of the Tore-Madeira Rise are likely to affect the U.S. coast. It is questionable whether earthquakes on the Puerto Rico Trench are capable of producing a large enough tsunami that will affect the U.S. Atlantic coast. More information is needed to evaluate the seismic potential of the northern Cuba fold-and-thrust belt. The hazard from a volcano flank collapse in the Canary Islands is likely smaller than originally stated, and there is not enough information to evaluate the magnitude and frequency of flank collapse from the Azores Islands. Both deterministic and probabilistic methods to evaluate the tsunami hazard from the margin are available for application to the Atlantic margin, but their implementation requires more information than is currently available.The work was funded by the U.S.-NRC Job Code V6166: Tsunami
Landslide Source Probability and Potential Impact on New and Existing
Power Plants
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