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Browsing by Author "Bruce, J. W."

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    Intensive Zero-Exchange Shrimp Production Systems - Incorporation of Filtration Technologies to Improve Survival and Growth
    Atwood, H. L.; Bruce, J. W.; Sixt, L. M.; Kegl, R. A.; Stokes, A. D.; Browdy, C. L. (Commercial Fish and Shellfish Technologies Program, Virginia Tech, 2005-06-01)
    Cost effective application of superintensive, biosecure marine production systems in the U.S. will depend upon proactive management of culture-water quality. More efficient production practices and effective management of waste materials from the shrimp aquaculture industry can allow for higher productivity, improved growth and survival, and pave the way for eventual application away from coastal areas. These improved production strategies are key factors contributing to profitability and environmental sustainability. Development of cost-effective management strategies includes application of mechanical and biological filtration devices to remove solids and nitrogenous products from culture systems. Accumulation of these waste products can limit system productivity and negatively impact cultured animals, increasing the potential for stress, disease, and mortality. Technologies developed to remove solids and maintain concentrations of nitrogenous waste products within acceptable limits include different types of filters used alone or in combination with a variety of media types. All of these technologies have achieved varying degrees of success. While use of expandable granular biofilters is not new, improvements have been made in the design and composition of the filtration media. This, in conjunction with an appropriate backwash regimen, encourages attachment and growth of nitrifying bacteria to accomplish clarification and nitrification in a single unit. The purpose of this study was to evaluate the effects of biological and mechanical filtration on production and selected water-quality criteria in zero-exchange, biosecure, superintensive shrimp production systems.
  • Natural resource management and land policy in developing countries: Lessons learned and new challenges for the World Bank
    Bruce, J. W.; Mearns, R. (London, UK: International Institute for Environment and Development,, 2004)
    The World Bank's concept of its development mission has deepened in recent years, with greater weight being given to poverty eradication and environmental stewardship. Natural resource management has taken its place alongside agriculture as a major rural development concern. A more integrated picture of rural livelihoods has emerged, along with a growing appreciation of the viability of production systems that make extensive but sustainable use of fragile resources, such as those of pastoralists. This paper looks at the World Bank's involvement in land policy issues in forests and protected areas and in pastoral and rangeland development, and summarises the lessons learned.
  • Old Wind in New Bottles: Creating New Institutions for Local Land Management
    Bruce, J. W.; Freudenberger, M. S.; Ngaido, T. (The World Bank, 1995)
    The document reviews the experiences of Niger, Senegal, Botswana, Gambia, and Tanzania in their attempts to replace traditional community-based tenure systems with modern legal tenure systems based on national statutes. Most attempts race evolved into a second wave of adaptive tenure models using decentralized (local) decision-making to implement quasi-standardized tenure systems for each nation.
  • The role of resource tenure in the management of natural resources in Africa
    Lawry, S. W.; Bruce, J. W. (1987)
    This paper sets out some basic concepts concerning the relationship between tenure in resources and natural resource management in Africa. It has been prepared at the request of AFR/TR, as a step in thinking through some of the issues raised by the Bureau's growing emphasis on natural resource management.
  • Searching for Land Tenure Security in Africa
    (Dubuque, Iowa: Kendall/Hunt Publishing Company, 1994)
    The principal aim of the book is to assess the relative efficiency of indigenous customary land use arrangements and state-imposed individual tenure in promoting agricultural production in Africa. It is based on eight case studies in seven countries. Chapter 1 presents an overview of the essential features of indigenous African tenure, given that it remains the dominant land use system in much of sub-Saharan Africa. This situation continues despite formal enactments under national law. Chapter 2 describes the methodological approaches adopted by the eight case studies to test a number of related hypotheses. The theoretical model is presented and the meaning of security of land tenure and its measurement in each of the case studies is defined. Data gathering methods and statistical analysis techniques are explained and relating to sampling strategy, particularly site and household selection are addressed. The case studies presented in chapters 3 to 10 summarize farm-level research undertaken between 1988 and 1990 by both the World Bank and ICRISAT. The countries examined are: Burkina Faso; Rwanda; Ghana; Kenya; Uganda; Somalia; and Senegal. The studies were focused on critical propositions about the relationship between security of tenure and agricultural development. The findings of the research are examined in the context of their implication for policy decision makers. Broadly stated they: cast doubt on the wisdom and cost effectiveness of large-scale, systematic programmes of compulsory titling for smallholders in rainfed agriculture; redirect attention to more incremental approaches to change in indigenous tenure systems; and suggest the need to redirect support of titling activities toward efforts focused on localities of particular need. (CAB Abstract)