4 resultados para Child-led research
em Aquatic Commons
Resumo:
Abstract The rapid growth of both formal and informal high density urban settlements around major water resources has led to increased pollution of streams, rivers, lakes and estuaries, due to contaminated runoff from these developments. The paper identified major contaminants to be : organic waste (sewage), industrial effluent, pesticides and litter. Pollutant loads vary depending on the hydrology of the urban area, local topography and soil conditions. In some instances, severe pollution of neighbouring and downstream water courses has been observed. The management of catchment land uses, riparian zones, in stream habitat, as well as in stream water flow patterns and quality are necessary in order to sustain the integrity and "health" of water resources, for fisheries and other developments. As such, attempts to ensure a certain level of water quality without attention to other aspects will not automatically ensure a "healthy" ecosystem even as fish habitat. Proper management leads to better water quality and conducive environment for increased fish production
Resumo:
A realistic alternative to traditional technology development and transfer has been utilized by the International Center for Living Aquatic Resources Management (ICLARM) to integrate pond fish culture into low-input farming systems in Malawi. Resource mapping was used to assess farm resources and constraints and introduce the concept of integrated resource management (IRM), the synergistic movement of resources between and among farm and household enterprises. Farmer-led IRM research projects are conducted on-farm and monitored by researchers through direct observation and on-station simulation of constraints and management practices. Technology-adoption rates by farmers involved in a pilot activity was 65% compared to 0% by farmers exposed only to top-down extension approaches. Within two years of adoption, every participating farmer had transferred the technology to an average of four other farmers without the involvement of the extension services.
Resumo:
The examination of a considerable amount of data has led to the conclusion that Lake Victoria should be considered as many lakes within a lake. This is not a vague and seemingly obvious remark based on the superficial observation that it is a very large lake containing numerous islands and with a highly indented coastline, and therefore providing variable local conditions. Such local conditions would exist in any lake whose basin departed from a simple geometric form. But evidence has now been collected to show that really significant differences occur between different regions within the lake. These differences are apparent from a variety of data, including the nature of the bottom deposits, the chemical and hydrological condition of the water, the amount and kind of plankton and the distribution and abundance of the fauna. Our findings are as yet somewhat sketchy, and it will be a long time before it will be possible to draw an adequate picture of the various regions of the lake; it is however, of great value to have reached a position enabling us to form this general concept. The most striking and definite evidence is derived, as might be expected, from hydrological data. Details of this work are contained in the hydrological section of this report. Any data recorded below should be considered as applying only to the particular areas mentioned. In other words it would, to draw an obvious example be wrong to suppose that because fish grow at a particular rate in one part of the lake they will grow at the same rate or to the same size in other regions of the lake.
Resumo:
Evolution of fisheries research and FIRRI The earliest approach to fisheries research in Uganda dates from the first fisheries survey of Lake Victoria by Michael Graham between 1927 and 1928 (Graham, 1929). Based on references to the rich fisheries that were reported to Graham, it appears that during the 18th Century, catch per net per night averaged 300 tilapia, a revelation that led Graham to conclude that Lake Victoria is a tilapia lake. The "tilapia" later came to be known as Tilapia esculenta and T variabilis (Oreochromis esculentus and O. variabilis) respectively.