996 resultados para April 25th


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This report presents the activities and results of the workshop Envisioning 2050: Climate Change, Aquaculture and Fisheries in West Africa. The objectives of the workshop were to discuss critical issues and uncertainties faced by the fisheries and aquaculture sector in Ghana, Senegal and Mauritania, build sectoral scenarios for 2050 and discuss the implication of these scenarios in the context of climate change for the countries and the region.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ihale is a large landing site lying approximately 65 km. from Mwanza along the main Mwanza-Musoma highway. Ihale Beach was selected as a potential candidate for the 3-beaches study because of its proximity to Mwanza, and hence suitability for frequent monitoring; and because it is served by a road accessible during the rainy seasons. As with the first training Participatory Rural Appraisal (PRA) on Kiumba Beach on Kenya's Rusinga Island, the objectives with this PRA were as follows: (a) To identify and understand Ihale's community-based organizations and institutions which have a role in the lake's fishery. (b) To consider the key issues which arise from this study for the involvement of communities and community-based organizations and/or institutions such as those at Ihale Beach, in the co-management of Lake Victoria's fishery.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Few detailed studies have been made on the ecology of the chalk streams. A complex community of plants and animals is present and much more information is required to achieve an understanding of the requirements and interactions of all the species. It is important that the rivers affected by this scheme should be studied and kept under continued observation so that any effects produced by the scheme can be detected. The report gives a synopsis of work carried out between 1971 and 1979 focusing on the present phase 1978-1979. It assumes some familiarity with the investigations carried out on the River Lambourn during the preceding years. The aims of the present phase of the project may be divided into two broad aspects. The first involves collecting further information in the field and includes three objectives: a continuation of studies on the Lambourn sites at Bagnor; comparative studies on other chalk streams; and a comparative study on a limestone stream. The second involves detailed analyses of data previously collected to document the recovery of the Lambourn from operational pumping and to attempt to develop simple conceptual and predictive models applicable over a wide range of physical and geographical variables. (PDF contains 43 pages)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this short project progress report is to investigate, in a catchment on which earlier nitrate data are available for comparison, seasonality and budgets, in relation to land use, of nitrate inputs, concentrations and loads. Sampling was undertaken from 1984-87 in the River Frome catchment and data on nitrate concentrations analysed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This report covers the period April to September, 1989. During this period sampling of invertebrates has concentrated on planktonic animals and those associated with one of the dominant macrophytes in the system, Nuphar lutea, the yellow water lily, since these are particularly important in the diets of larval and juvenile cyprinid fish. A proportion of samples has been partly analysed and some preliminary data are presented here.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Adult salmon and sea trout rod catches in the River Wyre have been subject to considerable variability over the years. Annual rod catches ranging from 6 to 401 have been reported since records began in 1905. It has long been suspected that the physical nature of the catchment, combined with anthropogenic influences, has resulted in a deleterious effect on the Wyre fishery. Acidification problems in the head water streams (Marshaw Wyre and Tarnbrook Wyre) have been reported and are thought to threaten salmon juvenile survival. The construction of Abbeystead Reservoir and an increased tendency towards rapidly rising water levels during storms (flashiness) 1 are thought to have a significant impact on spawning gravel quality and quantity, both of which are thought to be deteriorating. As part of an overall desire to maintain and improve the migratory salmonid population in the River Wyre, this project has been commissioned to investigate remedial action which may improve and enhance spawning success, leading to an eventual improvement in the status of adult stocks. The primary objective is to establish whether the quantity and/or quality of available spawning gravels are limiting migratory salmonid productivity. The investigations undertaken confirm the general observation that useable spawning gravels appear to be in short supply in the River Wyre, and may be the limiting factor influencing returning adult stock.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An electrofishing survey was undertaken in the period April 24th - 28th as part of the detailed biological study of the Calder Catchment being carried out by this department in early 1978. The sites to be fished were selected to indicate broadly the fishing status of the major sections of the main river and its larger tributaries and by no means intended to describe the fishing status of the whole catchment in detail. The results on the distributions of fish species are discussed, in general, in relation to the major polluting influences on the catchment. The results of the second survey are given and discussed separately in Appendix I.