Genetic diversity in wild stocks of the giant freshwater prawn (Macrobrachium rosenbergii): implications for aquaculture and conservation

The giant freshwater prawn (Macrobrachium rosenbergii) is cultured widely around the world but little is known about the levels and patterns of genetic diversity in either wild or cultured stocks. Studies have suggested that genetic diversity may be relatively low in some cultured stocks due to the history of how they were founded and subsequent exposure to repeated population bottlenecks in hatcheries. In contrast, wild stocks have an extensive distribution that extends from Southern Asia across Southeast (SE) Asia to the Pacific region. Therefore, wild stocks could be an important resource for genetic improvement of culture stocks in the future. Understanding the extent and patterns of genetic diversity in wild giant freshwater prawn stocks will assist decisions about the direction future breeding programs may take. Wild stock genetic diversity was examined using a 472 base-pair segment of the 16S rRNA gene in 18 wild populations collected from across the natural range of the species. Two major clades ("eastern" and "western") were identifi ed either side of Huxley’s line, with a minimum divergence of 6.2 per cent, which implies separation since the Miocene period (5-10 MYA). While divergence estimates within major clades was small (maximum 0.9 per cent), evidence was also found for population structuring at a lower spatial scale. This will be examined more intensively with a faster evolving mtDNA gene in the future.

Community fisheries management of freshwater lakes in Bangladesh

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.

Development of giant freshwater prawn broodstock

The commercial success of a giant freshwater prawn (Macrobrachium rosenbergii) hatchery depends upon the uninterrupted supply of the desired quantity and quality of broodstock. This study was an attempt to develop the broodstock near a hatchery, to be used for seed production throughout the year. The hatchery produced seed were stocked at the rate of 3/m2 after initial pond preparation. The prawns were fed with a pelleted diet (3 mm size) prepared by using locally available feed ingredients. The seed had an initial weight of 0.30 g and attained an average weight of 92.0 g and 62.0 g in males and females, respectively, within 11 months. Berried prawns were observed starting from the month of June (5%), after six months of stocking, with a maximum in September (60%). The percentage of berried prawns increased from June to September when the water temperature was optimum and decreased from December when it got cold. The broodstock developed in this experiment could be used in the hatchery after six months of stocking, and brooders could be used to produce seed for two seasons before being sold in the market.

Rice-freshwater prawn (Macrobrachium rosenbergii) farms in the Mekong Delta, Vietnam

Aquaculture in riceland has been practiced in Mekong Delta, Vietnam for a long time and integrated rice-freshwater prawn (Macrobrachium rosenbergii) farming has become more and more popular. The integrated farming systems developed and practiced by farmers in the area to produce more food and more cash crops are presented and discussed.

Freshwater prawn farming trials in Bangladesh

Details are given of pond trials conducted in Bangladesh regarding the culture of freshwater prawn (Macrobrachium rosenbergii ). Integrated rice and prawn farming systems were also experimented and results indicated that the prawn could be a suitable species for such integration. Such systems, pond or integrated, are suggested to be best practiced in the southeastern and southwestern areas of the country where there is tidal water exchange and post-larvae are naturally available.

Potentials for different models for freshwater aquaculture development in the Red River Delta (Vietnam) using GIS analysis

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.

Freshwater Biological Association 1929-1979. The first fifty years

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.

Salmonid & freshwater Fisheries statistics England & Wales 1989

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.

Salmonid & freshwater Fisheries statistics England & Wales 1990

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.

Salmonid & freshwater Fisheries statistics England & Wales 1992

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.

Salmonid & freshwater Fisheries statistics England & Wales 1994

This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1994 produced by the National Rivers Authority (NRA) in 1995. This report is focused on the maintenance, improvement and development of fisheries of England and Wales. This report is the sixth compilation of salmon and migratory trout catch statistics for England and Wales produced by the National Rivers Authority. For the years 1983-88, these statistics were published by the Ministry o f Agriculture, Fisheries and Food (MAFF), Directorate of Fisheries Research in their Data Report Series. The 1994 data have been presented in a broadly similar format to those of 1993.This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.

Salmonid & freshwater Fisheries statistics England & Wales 1996

This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1996 produced by the Environment Agency in 1997. The principal aim of the Environment Agency in respect of fisheries is to maintain improve and develop fish stocks, the basic fisheries resource, in order to optimise the social and economic benefits from their sustainable exploitation. This report is the second collation of salmon and migratory trout catch statistics for England and Wales produced by the Environment Agency. For the years 1989-94, these statistics were published by the National Rivers Authority (NRA) and the years 1983-88 by the Ministry of Agriculture, Fisheries and Food, Directorate of Fisheries Research in its Data Report series. The 1996 data, have been presented in a broadly similar format to those of 1995. This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.

Intensive biological survey of the Glaze Brook catchment. Supplementary report on the water quality as indicated by macrophytes. August 1981

This is the Intensive biological survey of the Glaze Brook catchment: Supplementary report on the water quality as indicated by macrophytes produced by the North West Water Authority in 1981. This report describes the results of the macrophyte survey including data on their distribution and the prevailing water quality (nutrient status and toxic metal contamination) It supplements the initial report,TS-BS-81-3, which described the macroinvertebrate survey. The aim of this project is to describe the distribution of macrophytes within the river, paying attention to areas where weed growth may directly affect water quality or amenity usage, and describe the distribution of toxic metals. In the survey 16 sites of 500 m lengths of river were analysed, noting the relative abundance and percentage cover of the macrophytes present, plant score and Community Description Class (C.D.C.) were computed.

Salmonid and freshwater fisheries statistics for England and Wales,1997

This report is the third collation of salmon and migratory trout catch statistics for England and Wales produced by the Environment Agency. For the years 1989-94, these statistics were published by the National Rivers Authority (NRA) and the years 1983-88 by the Ministry of Agriculture, Fisheries and Food, Directorate of Fisheries Research in its Data Report series. This report is designed to be a reference document of declared salmonid catches in England and Wales and is produced in the autumn following the season. Salmon stock assessment data including provisional catches, counter run estimates and some juvenile data are now published in an annual assessment for the International Council for the Exploitation of the Seas (ICES). The first report in this series was published jointly by the Environment Agency and the Centre for Environment, Fisheries & Aquatic Science (CEFAS) in April 1997 (Anon 1998).