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The study focused on contributing to the spatial knowledge of the impacts of land cover changes on beef cattle production under a changing climate in rangelands of the Lake Victoria Basin (LVB), so as to establish a strategy for improving beef cattle production in the area. We used supervised classification of satellite imagery to analyze land cover changes between the years 1980–2000 and 2000–2010. Results revealed that for the periods 1980–2000 and 2000–2010, settlements increased by 1% and 8%, and cultivated area increased by 0.58% and 0.30%, respectively. Riverine vegetation declined by 0.26% and increased by 0.16%, and woodlands declined by 6% and 13% respectively. The trend of beef cattle numbers against rainfall and pasture area (riverine vegetation and woodland) over the study period 1980–2010 showed a non-significant trend of increasing rainfall in the study area. In Ilemela District, pasture area and beef cattle numbers declined by 33% and 4% respectively. In Magu District, beef cattle numbers increased by 64% and pasture area declined by 84%. This implies that the effect of urbanization is more severe in Ilemela than in Magu District. Land use planning, enhancing of mixed crop-livestock farming systems, intensification of livestock practices, forage conservation, planting of fodder trees, and matching of cattle numbers with pasture availability are recommended. In addition, education is needed on effective cattle farming as a strategy for improving beef cattle production in the face of land cover changes due to climate variability in the area.  相似文献   
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The present study demonstrates the declining state of the major commercial fisheries of Lake Victoria, Kenya, a situation threatening sustainability of the lake's fishery. Data in the present study were derived from resource monitoring programmes that included hydro‐acoustics (2009–2018), trawl net fishing (2011–2018), frame surveys (2000–2016) and catch assessment surveys (2000–2015). The activities provided information on fish stocks and supported advice for fisheries management. The average fish stock densities for Tanzania, Uganda and Kenya of 8.92, 8.25 and 8.19 t/km2, respectively, were relatively similar. Diplomatic and sustainable efforts for harmony in fish harvesting among the fishers of the riparian countries are encouraged given the interdependence of the lake. The Kenyan and River Kagera regions had a higher proportion (≈ 4% each) of big‐sized Nile perch (≥50 cm total length) in 2018, signifying the critical breeding areas for Nile perch. To sustain the fishery, there is need to enforce a 36%–44% effort reduction for all the major fisheries, and enforcement of gear limits to avoid harvesting of immature fish and destruction of the lake ecosystem.  相似文献   
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The fisheries structure, fishing gear, fishing vessels and their ownership, landing sites and markets, as well as fisheries management and fishers’ participation were surveyed in three tropical islands: Pohnpei (Micronesia), Mafia (Tanzania), and Guimaras (Philippines), covering 127 fishers. Labour-intensive gear, including purse seines and ring nets, characterised Mafia fisheries. Fibre-reinforced plastic (FRP) boats characterised Pohnpei fisheries, and canoes with nonmarine engines were characteristic of Guimaras fisheries. Wooden plank boats with large crews were only seen in Mafia. From a gear/vessel ownership perspective, the fisher categories present were gear fishers, gear-vessel fishers, employers, and casual labour fishers. Casual labour fishers and employers were only apparent in Mafia. The fisheries in Pohnpei had a relatively early age of entry, which was attributed to the urban markets available and family cohesion, while community organisation-based management of these fisheries was weak. Mafia and rural Guimaras fishers depended on middlemen, due to the distance of the market. Deteriorating subsistence-related fishery dependency means that the Guimaras fishers’ community is at risk. The high shared gear/vessel ownership rates and levels of affiliation to community organisations in Mafia reflect government’s timely community sustainability enhancement initiative. Based on our analyses, we propose the “fishers’ community sustainability” concept. The sustainability of a fisher’s community can be judged on (1) the age of entry to the fisheries, (2) the monetary profits made at fish markets and through marketing, (3) the cohesion among the fishers, and (4) the level of subsistence-related dependency on the fishery. The fishery is key to community sustainability, thus ensuring fishery-dependent life. It is essential to consider the above indicators of fishers’ community sustainability during fisheries development.  相似文献   
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