细化搜索
结果 1-10 的 696
Incorporating Quadratic Scale Curves in Inverse Demand Systems 全文
2001
In this paper we introduce inverse demand systems that include quadratic scale terms. These systems are similar to regular quadratic demand systems introduced by Howe, Pollak, and Wales. A unique feature of these specifications is that they maintain linear scale curves as a special case. For illustrative purposes we estimate the Normalized Quadratic Inverse Demand‐Quadratic Scale System using monthly South Atlantic fish landings and valuation data, 1980‐1996. In estimation concavity is maintained locally, and the rank reduction procedures advocated by Diewert and Wales (1988a) are employed. The estimated model is then used to obtain welfare estimates associated with catch restrictions.
显示更多 [+] 显示较少 [-]Fish hatchery management
2001
Wedemeyer, Gary A.
The small scale reef fishery on the central north coast of Jamaica in 2000-2001: a biological and socio-economic survey. 全文
2001
Sary, Z.
This report provides detailed catch and effort information on the reef fishery on the north coast of Jamaica. The study area covered is from Rio Bueno, Trelawny, to Salem, St. Ann, a 22 km long segment of the central north coast. The reef fishery there is typical of the rest of the fishery on this coast, which is believed to be one of the most overfished in the Caribbean. The resource is easily accessible and it is an important source of food and employment, despite its overexploited state.
显示更多 [+] 显示较少 [-]Inshore fisheries management
2001
Symes, D. G (David Gilyard) | Phillipson, Jeremy
Fisheries management costs in Thai marine fisheries
2001
Willmann, R. | International Inst. of Fisheries Economics and Trade, Corvallis, OR (USA) eng | International Institute of Fisheries Economics and Trade. Conference eng 10-14 Jul 2000 10 Corvallis, OR (USA) | Pongbat Boonchuwong | Somying Piumsombun | Shriver, A. (comp.) | Johnston, R. (comp.)
Summary (En)
显示更多 [+] 显示较少 [-]Current policies, laws and regulations in relation to management of Kyoga basin lakes | Towards empowering fisheries officers to manage the fish stocks, biodiversity and environment of Kyoga basin lakes 全文
2001
Kamanyi, J. | Namisi, P
For the formulation of policies, laws and regulations for management of fisheries and aquatic systems there is a requirement for scientific knowledge to guide in this formulation. Such knowledge is used to guide in sustainable management of capture fisheries, integrating lake productivity processes into fisheries management, prevention of pollution and eutrophication of the aquatic environment, control of invasive weeds e.g. water hyacinth, enhancement of aquaculture production, reduction of post-harvest fish losses and ensuring fish quality, development of options for optimization of socio-economic benefits from fisheries and for co-management. | ACP - EU Fisheries and Biodiversity Project | Proceedings of a Training Workshop, 12th - 16th June 2001, Jinja, Uganda
显示更多 [+] 显示较少 [-]Managing small-scale fisheries: alternative directions and methods 全文
2001
F. Berkes | R. Mahon | P. McConney | R. Pollnac | R. Pomeroy
Paper looks beyond the scope of conventional fishery management to alternative concepts, tools, methods, and conservation strategies. There is, for example, broader emphasis on ecosystem management and participatory decision-making. This book focuses on small-scale fisheries in developing countries: the people who fish, their communities, and the linkages within and outside the fisheries systems.Chapers address the following issues:key concepts in fisheries managementfishery management planning and objectivesfishery informationproject assessment and evaluationfishery management processmanaging the commonscomanagement and community-based managementnew directions: a vision for small-scale fisheries
显示更多 [+] 显示较少 [-]The status of the fish stocks and environment of Kabaka's Lake 全文
2001
Fisheries Resources Research Institute | Lake Victoria Environment Management Project
Kabaka's lake (c. 0.7 km2) is a reservoir in Kampala's low lying Ndeeba zone which was created from a wetland landscape during the reign of the Buganda King Mwanga (1884 -1899). Oral accounts suggest that the original aim of constructing the lake was to improve navigation from the King's palace to the nearby Lake Victoria. This objective was never fulfilled due to subsequent political and socio-economic travels in Uganda: Even at present, the commercial and residential interest in the land associated with the present heavy settlements and modified landscape, makes it unlikely that the original objective of the Kabakas will be achieved. However, the reservoir has since remained in the King's estate and is still known as Kabaka's lake
显示更多 [+] 显示较少 [-]Compensatory density dependence in fish populations: importance, controversy, understanding and prognosis 全文
2001
Rose, Kenneth A. | Cowan, James H Jr | Winemiller, Kirk O | Myers, Ransom A. | Hilborn, Ray
Density‐dependent processes such as growth, survival, reproduction and movement are compensatory if their rates change in response to variation in population density (or numbers) such that they result in a slowed population growth rate at high densities and promote a numerical increase of the population at low densities. Compensatory density dependence is important to fisheries management because it operates to offset the losses of individuals. While the concept of compensation is straightforward, it remains one of the most controversial issues in population dynamics. The difficulties arise when going from general concepts to specific populations. Compensation is usually quantified using some combination of spawner–recruit analysis, long‐term field monitoring or manipulative studies, and computer modelling. Problems arise because there are limitations to each of these approaches, and these limitations generally originate from the high uncertainty associated with field measurements. We offer a hierarchical approach to predicting and understanding compensation that ranges from the very general, using basic life‐history theory, to the highly site‐specific, using detailed population models. We analyse a spawner–recruit database to test the predictions about compensation and compensatory reserve that derive from a three‐endpoint life‐history framework designed for fish. We then summarise field examples of density dependence in specific processes. Selected long‐term field monitoring studies, manipulative studies and computer modelling examples are then highlighted that illustrate how density‐dependent processes led to compensatory responses at the population level. Some theoretical and empirical advances that offer hope for progress in the future on the compensation issue are discussed. We advocate an approach to compensation that involves process‐level understanding of the underlying mechanisms, life‐history theory, careful analysis of field data, and matrix and individual‐based modelling. There will always be debate if the quantification of compensation does not include some degree of understanding of the underlying mechanisms.
显示更多 [+] 显示较少 [-]Product certification and ecolabelling for fisheries sustainability
2001
Roheim, Cathy A.
Product certification and ecolabelling are tools that can be used to support fisheries management. These tools, while interrelated and serving the same goal, have important differences as currently applied in fisheries. Product certification is commonly a measure mandated by governments, often mutually agreed upon by regional fisheries management organizations, in order to ensure that only legally harvested and reported fish landings can be traded and sold in the domestic or international markets. The principla objectives of an ecoloabelling scheme is to create a market-based incentive for better management of fisheries by creating consumer demand for seafood products from well-managed stocks.
显示更多 [+] 显示较少 [-]