47 resultados para Management and soil conservation
Resumo:
Lake Victoria in East Africa, supports socio-economically important fisheries for more than 30 million inhabitants in the lake basin. The lake had until the 1970's a diverse fish assemblage dominated by haplochromines species which formed at least 83% of the fish biomass (Kudhongania & Cordone 1974). The more than 500 haplochromine species in Lake Victoria, over 99% of them endemic, exploited virtually all the food sources in the lake (Witte and van Oijen 1990). Each species had its own unique combination of food and habitat preference (Goldschmidt et al., 1990).
Resumo:
Commonly adopted approaches to managing small-scale fisheries (SSFs) in developing countries do not ensure sustainability. Progress is impeded by a gap between innovative SSF research and slower-moving SSF management. The paper aims to bridge the gap by showing that the three primary bases of SSF management--ecosystem, stakeholders’ rights and resilience--are mutually consistent and complementary. It nominates the ecosystem approach as an appropriate starting point because it is established in national and international law and policy. Within this approach, the emerging resilience perspective and associated concepts of adaptive management and institutional learning can move management beyond traditional control and resource-use optimization, which largely ignore the different expectations of stakeholders; the complexity of ecosystem dynamics; and how ecological, social, political and economic subsystems are linked. Integrating a rights-based perspective helps balance the ecological bias of ecosystem-based and resilience approaches. The paper introduces three management implementation frameworks that can lend structure and order to research and management regardless of the management approach chosen. Finally, it outlines possible research approaches to overcome the heretofore limited capacity of fishery research to integrate across ecological, social and economic dimensions and so better serve the management objective of avoiding fishery failure by nurturing and preserving the ecological, social and institutional attributes that enable it to renew and reorganize itself. (PDF contains 29 pages)
Resumo:
Atlantic and Gulf Coast shorelines include some of the most unique and biologically rich ecosystems in the United States that provide immeasurable aesthetic, habitat and economic benefits. Natural coastal ecosystems, however, are under increasing threat from rampant and irresponsible growth and development. Once a boon to local economies, complex natural forces – enhanced by global climate change and sea level rise - are now considered hazards and eroding the very foundation upon which coastal development is based. For nearly a century, beach restoration and erosion control structures have been used to artificially stabilize shorelines in an effort to protect structures and infrastructure. Beach restoration, the import and emplacement of sand on an eroding beach, is expensive, unpredictable, inefficient and may result in long-term environmental impacts. The detrimental environmental impacts of erosion control structures such as sea walls, groins, bulkheads and revetments include sediment deficits, accelerated erosion and beach loss. These and other traditional responses to coastal erosion and storm impacts- along with archaic federal and state policies, subsidies and development incentives - are costly, encourage risky development, artificially increase property values of high-risk or environmentally sensitive properties, reduce the post-storm resilience of shorelines, damage coastal ecosystems and are becoming increasingly unsustainable. Although communities, coastal managers and property owners face increasingly complex and difficult challenges, there is an emerging public, social and political awareness that, without meaningful policy reforms, coastal ecosystems and economies are in jeopardy. Strategic retreat is a sustainable, interdisciplinary management strategy that supports the proactive, planned removal of vulnerable coastal development; reduces risk; increases shoreline resiliency and ensures long term protection of coastal systems. Public policies and management strategies that can overcome common economic misperceptions and promote the removal of vulnerable development will provide state and local policy makers and coastal managers with an effective management tool that concomitantly addresses the economic, environmental, legal and political issues along developed shorelines. (PDF contains 4 pages)
Resumo:
Atlantic and Gulf Coast shorelines include some of the most unique and biologically rich ecosystems in the United States that provide immeasurable aesthetic, habitat and economic benefits. Natural coastal ecosystems, however, are under increasing threat from rampant and irresponsible growth and development. Once a boon to local economies, complex natural forces – enhanced by global climate change and sea level rise - are now considered hazards and eroding the very foundation upon which coastal development is based. For nearly a century, beach restoration and erosion control structures have been used to artificially stabilize shorelines in an effort to protect structures and infrastructure. Beach restoration, the import and emplacement of sand on an eroding beach, is expensive, unpredictable, inefficient and may result in long-term environmental impacts. The detrimental environmental impacts of erosion control structures such as sea walls, groins, bulkheads and revetments include sediment deficits, accelerated erosion and beach loss. These and other traditional responses to coastal erosion and storm impacts- along with archaic federal and state policies, subsidies and development incentives - are costly, encourage risky development, artificially increase property values of high-risk or environmentally sensitive properties, reduce the post-storm resilience of shorelines, damage coastal ecosystems and are becoming increasingly unsustainable. Although communities, coastal managers and property owners face increasingly complex and difficult challenges, there is an emerging public, social and political awareness that, without meaningful policy reforms, coastal ecosystems and economies are in jeopardy. Strategic retreat is a sustainable, interdisciplinary management strategy that supports the proactive, planned removal of vulnerable coastal development; reduces risk; increases shoreline resiliency and ensures long term protection of coastal systems. Public policies and management strategies that can overcome common economic misperceptions and promote the removal of vulnerable development will provide state and local policy makers and coastal managers with an effective management tool that concomitantly addresses the economic, environmental, legal and political issues along developed shorelines. (PDF contains 4 pages)
Resumo:
The Geologic Atlas of the United States was digitized and stored in the Texas A&M University institutional repository. Extensive metadata was created which emphasized the geographic and geologic aspects of the material. The map sheets were also convered into kml files for Google Earth and ESRI shape files for use in GIS. A Yahoo!Map interface allows for visualization of the locations of each folio and user friendly browsing across the collection. Details of the project will be discussed, including the selection, digitization methods and standards, preservation, metadata, web presence and staffing. Its storage in DSpace, assortment of publicity outlets, and its inclusion in targeted clearinghouses expand its potential use to national and international audiences.
Resumo:
Fisheries co-management is increasingly seen as a solution to the problems of resource use conflicts and overexploitation. The importance of transactions costs may not have been given adequate attention. The transaction costs are 1) information costs, 2) collective decisionmaking tools, and 3) collective operational costs. The various components of transaction costs of fisheries co-management systems are described in this paper. These costs need to be determined for evaluating the feasibility of a co-managed fishery compared to a centrally managed one.
Resumo:
This paper uses an industrial organization approach to trace the impact on Madeira Beach, Fla., and surrounding areas of a 1-month closure of the grouper fishery from 15 February 2001 to 15 March 2001. A proposed 2-month closure is also evaluated. This approach identifies the economic relationships in the industry based on both product and place. The empirical analysis measures the losses in employment and income, information that enriches social and anthropological research on fishery-dependent communities. The 1-month closure is estimated to have reduced annual catches landed in Madeira Beach by 9.7–10.1% and annual revenues by 9.3–11.5%. These reductions are associated with a direct loss of about 33 full-time (annualized) jobs and personal income losses between $8 and 12 million in Madeira Beach and Pinellas County over a 10-year period. If the closure occurs for 2 months, annual landings and revenues will be reduced an estimated 17–21% and 20–23%, respectively.
Resumo:
This paper provides an historical review of homarid lobster fisheries, the development and usage of lobster hatcheries, and much of the research influenced by hatchery-initiated studies on natural history, physiology, and morphological development of the lobster, Homarus spp. Few commercial lobster hatcheries exist in the world today, yet their potential usage in restocking efforts in various countries is constantly being reexamined, particularly when natural stocks are considered “overfished.” Furthermore, many individual researchers working on homarid lobsters use smallscale hatchery operations to provide the animals necessary for their work as well as animals reared and provided by various governmental agencies interested in specific projects on larvae, postlarvae, or juveniles. Such researchers can benefi t from the information in this review and can avoid many pitfalls previously documented. The development of hatcheries and the experimental studies that were generated from their activities have had a direct impact on much of the research on lobsters. The past work arising from hatchery operations—descriptions of life stages, behavior, physiology, etc.—has generally been confirmed rather than refuted and has stimulated further research important for an understanding of the life history of homarid lobsters. The connections between homarid fisheries and hatchery operations (i.e. culturing of the lobsters), whether small- or large-scale for field and laboratory research, are important to understand so that better tools for fishery management can be developed. This review tries to provide such connections. However, the rearing techniques in use in today’s hatcheries—most of which are relics from the past—are clearly not effi cient enough for large-scale commercial aquaculture of lobsters or even for current restocking efforts practiced by several countries today. If hatcheries are to be used to supplement homarid stocks, to restock areas that were overfished, or to reintroduce species into their historical ranges, there is a clear need to further develop culture techniques. This review should help in assessments of culturing techniques for Homarus spp. and provide a reference source for researchers or governmental agencies wishing to avoid repeating previous mistakes.
Resumo:
The groundfish resources of the U.S. Exclusive Economic Zone (EEZ) off Alaska, dominated by Alaska or walleye pollock, Theragra chalcogramma, Pacific cod, Gadus macrocephalus, and flatfishes, Pleuronectidae, can sustain annual commercial harvests well in excess of 2 million metric tons (t). As recently as 1979, foreign fisheries took 99 percent of the annual harvest supported by these resources. This has changed dramatically during the 1980's. The foreign fisheries have received rapidly decreasing allocations, first as joint venture fisheries expanded and, more recently, as the domestic fisheries have grown. Joint venture fisheries are fisheries in which domestic fishing vessels deliver their catch directly to foreign processing vessels in the EEZ. By 1986, the joint venture and domestic fisheries accounted for 66 percent and 8 percent, respectively, of the annual harvest. The preliminary corresponding figures for 1987 are 78 and 18 percent.