911 resultados para freshwater prawn
Resumo:
The management of African freshwater fisheries in Southern African Development Coordination (SADC) countries is discussed. Changes in catch and fishing effort in the SADC freshwater fisheries in the past 50 years, the main causes behind the patterns of change in fishing effort, the effects of fishing effort and environment on the regeneration of fish stocks, as well as existing and proposed fisheries management regulations are investigated.
Resumo:
Length-weight relationships of 73 fish populations, covering 20 families, 28 genera and 40 species inhabiting freshwater ecosystems in Nigeria, were estimated (73 cases) or assembled from the literature (20 cases), and tested for difference between ecosystem types, There were no significant differences in the exponent of these relationships between lotic and lentic systems.
Resumo:
Length-weight relationships were calculated for nine fish species from Lake Volvi (Macedonia, Hellas), caught with gillnets of five different mesh sizes between October 1995 and October 1996. In addition, length-weight relationships for 24 Greek freshwater fish species and one hybrid were also obtained from the literature. The values of the exponent of the length-weight relationships for all fish species examined ranged between 2.14 and 3.70 (mean = 3.12; SE=0.0321), and the median value was 3.19.
Resumo:
The Oxbow Lakes Small Scale Fishermen Project in western Bangladesh is primarily a Social Fisheries Project. The project aims at self-management of the Oxbow lakes fishing and fish farming by members of the local communities and the sharing of the benefits in an equitable manner. Project emphasis is on social and institutional aspects of the community water resource management and on improving the fish yields through better fisheries practices.
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Economic analysis and performance of the integrated rice-prawn farming systems in the Mekong Delta (Vietnam) are reviewed, including the problems and constraints of this integrated system technology.
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A progressive farmer in Tamil Nadu state, India experimented with crop rotation and successfully cultured Penaeus monodon during the dry season and Macrobrachium rosenbergii during the wet season. The details of M. rosenbergii culture are discussed in this article. Rotation with M. rosenbergii did help the farmer overcome the disease problem since farmers who exclusively cultured P. monodon in the nearby areas during the same season suffered losses due to white spot disease.
Resumo:
This study was an attempt to apply land-based GIS analysis for freshwater aquaculture planning in the Red River Delta of Vietnam. It was based on diverse data sources in order to help decision makers at the site and also to contribute to the modelling of selection processes for aquaculture development planning in the region.
Resumo:
Booklet telling the story of the FBA from its founding in 1929 until its Golden Jubilee in 1979. The booklet aimed to produce a readable account of those aspects of freshwater biology that have been among the main themes of the Association's research, as well as some aspects of its history and the philosophy guiding its foundation. The publication includes many images of the FBA's work and history as well as images and illustrations on lake ecology and applied science.
Resumo:
Prawn trawling occurs in most states of Australia in tropical, subtropical, and temperate waters. Bycatch occurs to some degree in all Australian trawl fisheries, and there is pressure to reduce the levels of trawl fishery bycatch. This paper gives a brief overview of the bycatch issues and technological solutions that have been evaluated or adopted in Australian prawn-trawl fi sheries. Turtle excluder devices (TED’s) and bycatch reduction devices (BRD’s) are the principal solutions to bycatch in Australian prawn-trawl fisheries. This paper focuses on a major prawn-trawl fishery of northeastern Australia, and the results of commercial use of TED’s and BRD’s in the Queensland east coast trawl fishery are presented. New industry designs are described, and the status of TED and BRD adoption and regulation is summarized. The implementation of technological solutions to reduce fishery bycatch is assumed generally to assist prawn-trawl fisheries within Australia in achieving legislative requirements for minimal environmental impact and ecological sustainable development.
Resumo:
During a fishing trip to record video footage of fish escaping from a by-catch reducing device located in a commercial prawn trawl, two bottlenose dolphins, Tursiops truncatus, were observed to actively manipulate the codend at the seabed, removing and consuming components of catch (mostly juvenile whiting, Sillago spp.). The observed feeding pattern suggests a well established behavioral response to trawling activities and is discussed with respect to (1) the potential nutritional benefit that dolphins may derive from such activities and (2) the effects that scavenging may have on selectivity of the gear.
Resumo:
The temporal variation of components of a moderately diverse (H=1.46) tropical estuarine fish assemblage (long. 146°30'E, lat. 8°45'S) was directed by salinities that had been determined by local oceanographic and probably topographic conditions. For this assemblage, two types of intrayear component profiles are predicted. Pooled data (1988-91) reveal a large component of regular/resident species (43%) in an assemblage which has been under a narrow temperature regime «5T). These results facilitate a discussion on the relevance and usefulness of three hypotheses often cited in studies concerning species diversity and component characteristics of the subtropical/tropical coastal nonreef fish assemblages. Manifestations of the assemblage are reflected in catch composition and weights of 39 trials conducted for a selective prawning gear whose performance in bycatch reduction, mainly for finfishes, is judged by an index, E, we have previously proposed. This gear is capable of harvesting the prawn while conserving the demersal fish. Behavioral responses to netting of the prawns and the finfishes, especially the nearshore surface schoolers such as leiognathids, are discussed from several points of view. An adaptation in terms of group selection for leiognathids of their locking mechanism of median fin spines has been interpreted. For the purpose of bycatch reduction or E enhancement, suggestions for improvements in net design and trawl configuration by considering the behavioral features of fish are made. Our original formula of E is modified for general use. Bycatch problems in the regional prawn fisheries and their possible impacts on fishery planning and development in Papua New Guinea as a developing country are discussed. The gear tested may offer enormous ecological and economic benefits. The gear is multipurpose, extremely simple, and can also be used as a biological sampler.
Resumo:
This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1989 produced by the National Rivers Authority (NRA) in 1989. This report is focused on the maintenance, improvement and development of fisheries of England and Wales. This report is the first on salmon and migratory trout catch statistics for England and Wales published by the National Rivers Authority (NRA). From 1989 onwards, these statistics will appear each year as NRA fisheries statistics reports replacing the Data Report Series which was published by the Ministry of Agriculture Fisheries and Food (MAFF) Directorate of Fisheries Research. This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.
Resumo:
This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1990 produced by the National Rivers Authority (NRA) in 1992. This report is focused on the maintenance, improvement and development of fisheries of England and Wales. This report is the second compilation of salmon and migratory trout catch statistics for England and Wales published by the National Rivers Authority (NRA). Before 1989, these statistics were published by the Ministry of Agriculture Fisheries and Food (MAFF) Directorate of Fisheries Research in their Data Report Series. The 1990 data have been presented in a broadly similar format to those of 1989. However, two further NRA regions, four in all, provided effort data for rod fisheries in 1990. This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.
Resumo:
This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1992 produced by the National Rivers Authority (NRA) in 1994. This report is focused on the maintenance, improvement and development of fisheries of England and Wales. This report is the fourth compilation of salmon and migratory trout catch statistics for England and Wales published by the National Rivers Authority. For the years 1983-88, these statistics were published by the Ministry of Agriculture, Fisheries and Food (MAFF), Directorate of Fisheries Research in their Data Report Series. Other than for rod catches, the 1992 data have been presented in a broadly similar format to those of 1991, Presentation of the rod data however has changed considerably due to the introduction in January 1992 of the first National Rod Fishing Licence. This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.