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排序方式: 共有193条查询结果,搜索用时 15 毫秒
51.
Using Local Knowledge as a Research Tool in the Study of River Fish Biology: Experiences from the Mekong 总被引:1,自引:0,他引:1
John Valbo-Jørgensen Anders F. Poulsen 《Environment, Development and Sustainability》2000,2(3-4):253-376
River fisheries are extremely important for food-security among the rural poor in many tropical countries. The growing populations and rapid industrialisation of these countries require that appropriate action should be taken to sustain the resources for future generations. However, an incomplete understanding of river fisheries biology, at the managerial level, often hampers proper planning and management. This is partly due to the difficult access to large parts of such river basins, the complex nature of the fisheries, and in many cases a severe lack of research funds. In contrast, the thousands, or often millions of people who live along the shores of the rivers and rely on the fishery for their daily survival, have a very intimate knowledge of the behaviour and biology of the fish. In this situation, gathering the knowledge of the fishers may provide politicians or planners with baseline knowledge in a relatively quick and cheap way.This paper discusses two years of research using local knowledge in the study of fish migration and spawning in the Lower Mekong Basin. The study involves semi-structured interviews with 355 expert fishermen in four countries along 2,400 km of the Mekong mainstream. By piecing together information from fishermen in different areas, we were able to construct migration maps, and provide rough estimates of the spawning period for 50 fish species. We conclude that river fisheries research can benefit significantly from local knowledge as the basis for future research. 相似文献
52.
ABSTRACTHigh seas fisheries remain one of the least transparent global production practices. Distance from shore, coupled with the highly mobile nature of fish stocks, has put attention on new monitoring, control and surveillance technologies to collect spatially referenced data on the location of fishing vessels, gears and even fish stocks and eradicate illegal, unreported and unregulated fishing activity. Faced with their nascent implementation, research is yet to address how these technologies are reconfiguring the roles and responsibilities of public and private actors involved in fisheries management, including who collects and controls fisheries related information. In this paper, we compare three monitoring, control and surveillance technologies that are gaining traction in fisheries; the use of private fish attraction devices in oceanic tuna fisheries, unmanned public drones for marine surveillance and global satellite monitoring of fishing vessels. In doing so, we question how different configurations of actors are structuring flows of information and with what effect on sustainability performance of high seas fisheries. We also explore how these technologies configure new (and imagined) geographies of high seas fisheries which challenge existing modes of fisheries management. 相似文献
53.
Inadequate trade policies, globalization of the fishing industry, dominance of Europe's distant water fleets, declarations of exclusive economic zones (EEZs) by neighbouring West African nations, overfishing and a lack of good governance contributed to the decline of Ghana as a regional fishing nation, a position it had held since the 18th century. The prohibitive cost of access arrangements limited Ghana's access to distant waters. The country's marine environments have been impacted by overexploitation of stocks and the use of destructive methods. Subsistence fishing has become the sole means of survival for many fishers. The decline of the fishing sector has limited the country's ability to meet domestic demand and threatened the economic and food security of many Ghanaians. The article traces the early history of Ghana's fisheries, their gradual decline during the last four decades, and outlines recommendations for policy changes to address the situation and steer the nation on a course towards sustainable fisheries. 相似文献
54.
Rice versus fish revisited: On the integrated management of floodplain resources in Bangladesh 总被引:2,自引:0,他引:2
Disproportionately little attention has been paid to the dry season trade‐off between rice and (inland capture) fish production on the floodplains of Bangladesh, compared to the same trade‐off during the flood season. As the rural economy grows increasingly dominated by dry‐season irrigated rice production, and floodplain land and water come under ever‐increasing pressure during the dry winter months, there is an urgent need to focus attention on these dry months that are so critical to the survival and propagation of the floodplain resident fish, and to the poor people that depend on these fish for their livelihood. This article examines three important dry‐season natural resource constraints to floodplain livelihoods in Bangladesh, and finds a common factor at the heart of all three: rice cultivation on lands at low and very low elevations. The article articulates the system interlinkages that bind these constraints and the long‐run trend towards irrigated rice cropping on lower‐lying lands, and suggests a management approach based on locally tailored strategies to arrest this trend. Apart from its direct relevance to the floodplains of Bangladesh, which support more than 100 million people, these lessons have relevance for river floodplain systems elsewhere in the developing world, notably the Mekong Delta. 相似文献
55.
长江流域水库密集,蕴藏着巨大的渔业资源,由于人口增加,耕地减少,保护土地成为国策,今后靠用耕地开挖池塘养鱼来增加水产品产量已不可能;我国传统的四大海洋经济鱼类,因过度捕捞,已不成渔汛,湖泊不断减少,江河环境受到不同程序的污染,使湖泊,灌河渔业产量下降。相反,随着岁月流长,人类进步,经济繁荣,人工湖-即水库将会不断增加。 相似文献
56.
Problems and constraints in Philippine municipal fisheries: The case of San Miguel Bay,Camarines Sur
The Philippine fisheries accounted for 3.7% of the gross national product at current prices. The sector employed about 990,872
persons. Of the divisions comprising the industry, municipal fisheries continued to contribute the largest share of fish production.
However, the sector is beset with problems, many of which are best examplified by the case of San Miguel Bay (SMB). This paper
presents the problems and constraints confronting SMB, a common property resource. This bay's open access condition has led
to various problems, such as declining fishery resources, depressed socioeconomic conditions, illegal fishing, increasing
population, and conflict among resource users. A poor marketing system, low level of fishing technology, fishermen's noncompliance
and authorities' lax enforcement of rules and regulations, as well as lack of alternative sources of income further characterize
the condition in SMB. Establishment of fishing rights, improvement of the marketing system, provision of alternative sources
of income, and improvement of fishing technology were some of the solutions suggested. One major constraint, however, is financial,
Comanagement complemented with other management tools has been proposed in addressing the problems in SMB. 相似文献
57.
Klaus Eisenack Juergen Scheffran Juergen Peter Kropp 《Environmental Modeling and Assessment》2006,11(1):69-79
The pressure on marine renewable resources has rapidly increased over past decades. The resulting scarcity has led to a variety
of different control and surveillance instruments. Often they have not improved the current situation, mainly due to institutional
failure and intrinsic uncertainties about the state of stocks. This contribution presents an assessment of different management
schemes with respect to predefined constraints by utilizing viability theory. Our analysis is based on a bio-economic model
which is examined as a dynamic control system in continuous time. Feasible development paths are discussed in detail. It is
shown that participatory management may lead to serious problems if a purely resource-based management strategy is employed.
The analysis suggests that a less risky management strategy can be implemented if limited data are available. 相似文献
58.
Mekong River Fish Conservation Zones in Southern Laos: Assessing Effectiveness Using Local Ecological Knowledge 总被引:2,自引:0,他引:2
Small-scale fisheries are important in Laos, where rural people heavily depend upon Mekong River and tributary fish stocks
for their livelihoods. Increasing pressures from human exploitation and habitat disturbance, however, have raised serious
concerns about the potential depletion of various species. This has led to the establishment of large numbers of Fish Conservation
Zones (FCZs) or “no-take” fish sanctuaries in southern Laos based on a “community-based fisheries co-management” framework.
This study uses the local ecological knowledge (LEK) of fishers to assess the effectiveness of village-managed FCZs in enhancing
fish stocks in the mainstream Mekong River in Khong District, Champasak Province. Focus group interviews about species that
are believed to have benefited from different FCZs are compared with parameters such as FCZ area, age, depth, localized gradient,
water velocity, and the presence of wetland forests nearby. The results suggest that no one aspect is likely to account for
variations in fish stocks; rather, it is the interaction between numerous factors that has the largest impact. Secondly, the
results indicate that microhabitat diversity and protection are critical for maintaining and enhancing Mekong fisheries. Deep-water
pools are particularly important as dry season refuges for many fish species, and FCZ depth may be the single most important
environmental factor affecting the success of FCZs in the Mekong River. FCZs have the most potential to benefit relatively
sedentary species, but may also benefit highly migratory species, given the right conditions. This study shows that integrated
approaches to stock assessment that employ LEK and scientific fisheries management have considerable potential for improving
Mekong capture-fisheries management. 相似文献
59.
Olanike K. Adeyemo 《The Environmentalist》2003,23(4):297-306
Throughout the world, human use of water, and bad planning have led to drier and polluted rivers, lakes, and groundwater resources with dramatic effects on the natural ecosystems. Nigeria's vast freshwater resources are among those most affected by environmental stress imposed by human population growth, urbanization, and industrialization. Disposal and management of wastes in Nigeria present serious environmental problems. The usual methods of waste disposal in the country are: land filling, dumpsites, land spreads, water disposal, and incineration. Each of these methods has serious environmental implications because of their potential to pollute and contaminate underground and surface water bodies in the country. Major cities in Nigeria face serious water pollution crises, in which lack of environmental control of water-dependent activities (including domestic, agricultural, and industrial) play an important part. Fish and marine resources in the country face total collapse or extinction, due to over-fishing and destruction of marine life and natural habitats by pollution of water bodies. Unregulated and excessive use of pesticides for fishing and the deliberate disposal and dumping of toxic and hazardous wastes into water bodies are significant causes of massive fish kills and loss of aquatic life and habitats in the country. The protection of water quality and aquatic ecosystem as a vulnerable resource, essential to sustain life, development and environment is of utmost importance to prevent further pollution and degradation of Nigeria's freshwater resources. Integrating operational measures for safeguarding adequate levels of protection of endemic habitats remains a major challenge. There is therefore a need to examine in tandem the entire range of uses to which freshwater is put, and to design services which neither squander precious resources nor fail to respect other, competing and complementary water needs.This paper attempts to provide an overview of the Nigerian freshwater resources, to assess the pollution status of inland waters, identify the sources of pollution, and infer the consequent effect on fisheries resource. Recommendations were proffered on the strategies to employ to ensure that Nigerian fishery resources are adequately managed in order to address the issue of food security. 相似文献
60.
Jonathan G. Taylor Stephen D. Ryder 《Journal of the American Water Resources Association》2003,39(1):183-189
ABSTRACT: The tri‐state river basins, shared by Georgia, Alabama, and Florida, are being modeled by the U.S. Fish and Wildlife Service and the U.S. Army Corps of Engineers to help facilitate agreement in an acrimonious water dispute among these different state governments. Modeling of such basin reservoir operations requires parallel understanding of several river system components: hydropower production, flood control, municipal and industrial water use, navigation, and reservoir fisheries requirements. The Delphi method, using repetitive surveying of experts, was applied to determine fisheries' water and lake‐level requirements on 25 reservoirs in these interstate basins. The Delphi technique allowed the needs and requirements of fish populations to be brought into the modeling effort on equal footing with other water supply and demand components. When the subject matter is concisely defined and limited, this technique can rapidly assess expert opinion on any natural resource issue, and even move expert opinion toward greater agreement. 相似文献