A decade of monitoring and management of freshwater algae, in particular Cyanobacteria, in England and Wales

Although the toxicity of cyanobacteria has been known for many years, cyanobacteria-related problems in the UK were generally limited in frequency. However, this all changed and became of national concern following the exceptional environmental conditions in the autumn of 1989, when widespread cyanobacterial blooms and scums developed in fresh waters. This paper summarises the Environment Agency's monitoring programme for freshwater algae since 1991 and describes the actions the Environment Agency has taken as a result of the monitoring data.

Genetic engineering of microorganisms: free release into the environment

Genetic engineering now makes possible the insertion of DNA from many organisms into other prokaryotic, eukaryotic and viral hosts. This technology has been used to construct a variety of such genetically engineered microorganisms (GEMs). The possibility of accidental or deliberate release of GEMs into the natural environment has recently raised much public concern. The prospect of deliberate release of these microorganisms has prompted an increased need to understand the processes of survival, expression, transfer and rearrangement of recombinant DNA molecules in microbial communities. The methodology which is being developed to investigate these processes will greatly enhance our ability to study microbial population ecology.

Aspects of the biology and population dynamics of freshwater mussels in Lake Kariba and Lake McIlwaine

The essential aim of this study was to provide a broad foundation of biological knowledge upon which a programme of mussel utilization and management could be built. Results of the study are presented in three main sections. Part 1 describes the stock of Lake Kariba and Lake McIlwaine; part 2 describes various aspects of the breeding biology of the three species; and part 3 presents the results of morphological, biochemical and age analyses - aspects which are used for initial standing crop and production calculations. The final discussion concludes the thesis with a general examination in ecological terms of the factors which have influenced the development and nature of the mussel faunas of the two lakes under consideration.

African freshwater fisheries: what needs to be managed?

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.

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.

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).

Salmonid and freshwater fisheries statistics for England and Wales,1998

This report is the fourth 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 for 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. 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 second report in this series was published jointly by the Environment Agency and the Centre for Environment, Fisheries & Aquatic Science (CEFAS) in April 1998 (Anon 1999).

Seed production and culture techniques of Genetically Improved Farmed Tilapia (GIFT) in brackishwater environment

Effects of different levels of salinity on survival, growth and gonadal development of Genetically Improved Farmed Tilapia (GIFT) were studied under laboratory conditions in glass aquarium, for a period of ten weeks. The initial individual size of the GIFT was 20.23±4.45 and the salinity levels tested were 0, 5, 10, 15 and 20 ppt. The highest survival of 87.5% was found in 0 ppt and the lowest 60.5% in 20 ppt. Though the survival decreased progressively with increased salinity, there were no significant differences (P>0.05) among 0, 5, and 10 ppt. Similar to what has been observed in survival, the specific growth rate (SGR %/day) also decreased as of 1.30, 1.24, 1.08, 0.90 and 0.71, respectively, with the increased salinity of 0, 5, 10, 15 and 20 ppt. The gonadal development was highest in 0 ppt with a GSI value of 3.75 and lowest of 2.01 in 20 ppt. In the second experiment, gonadal development and seed production performance of GIFT in brackishwater condition were investigated for a period of three months. Each of the three fine meshed hapas of 20 square meters made from nylon net was placed in a freshwater (0 ppt) and in a brackish water (10-15 ppt) pond of the Brackishwater Station (BS). GIFT of 65 g average weight from a single cohort were stocked into three hapas at a rate of 2 per m. The male vs female ratio was 1:3. The development of gonad was faster with the higher gonadosomatic index (GSI %) of 3.85 % in freshwater condition than that of 2.73 % in brackish water. Within three months of the study period, a total of 70,510 and 44,250 GIFT fry were produced respectively, in freshwater and brackishwater conditions. Finally under third experiment, a participatory on-farm trial was carried out to evaluate the production performance of GIFT in monoculture and in polyculture with silver barb in coastal freshwater pond conditions. Nine ponds were selected for three treatment combinations of GIFT monoculture (T1), GIFT and silver barb polyculture (T2), and silver barb monoculture (T3). The ponds have been stocked in April, 05 at a density of 25,000 fry per ha. Fishes were fed with rice bran at the rate of 6% bw per day. In one month culture period, GIFT attained an average weight of 16.27 g in monoculture and 17.23 g in polyculture, against an average stocking weight of 0.37 g. Silver barb reached an average weight of 16.62 g in polyculture with GIFT and 10.01 g in monoculture, against an average stocking weight of 3.79 g.

A review of the distribution of organic compounds in freshwater lakes and rivers

The paper reviews the distribution of organic compounds in freshwater lakes and rivers. The study of dissolved organic matter in natural lakes and rivers is of importance for a variety of reasons. The organic matter may serve in part or whole as an energy source for organisms living in the aquatic environment, or it may supply them with materials essential for their nutrition.

Study and comparison on freshwater snail fauna in the paddy fields and related river and lake (Babolroad & Parishan) water supply in Mazandaran & Frace provinces of Iran

As a result of this investigation, for the first time from Babolroud river in Iran is 15 species identified, which they belong to 8 genera, from 7 families. The most and least distribution, 13 and 5 species, belong to Miandasht and Rostaye Anarestane Babol stations respectively, which they are 50 kilometers away from each other. Also 20 species belong to 10 genera from 6 families were identified in Parishan lake. The most the distribution belong to stations 1 and 5 with 6 and 18 species respectively. The most commonly distributed family is Lymnaeidae with 6 species: Lyamnaea truncatula, L. auricularia, L. palustris, L. pereger, L. stagnalis and L. gedrosiana, which L. trancatula is identified as the most frequent and has medical importance. L. stagnalis is identified to be the most important to agriculture. Planorbis planorhis, Physa acuta, Lymnaea pereger, Bithynia tenculata and Vavata piscinalis are reported for the first time from this region.

A short survey of the environment at the dumping site for Santa Cruz Harbor dredging and A study of seaward dipping internal structures in marine ripple marks at Whaler's Cove, California. Annual report, Part 4, August 1972

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Review of river fisheries valuation in tropical Asia

This study attempts to estimate the economic value of riverine fisheries in tropical Asia and quantify the economic impacts of any changes to the environment that affects rivers and hence fisheries. The value of riverine fisheries has been considered in the following two ways: firstly, through a compilation and summary of the results of existing studies on this topic; secondly, by estimating the direct use value of riverine and floodplain fishing by country using quantities and freshwater fish prices derived from various sources. Furthermore, a review of the characteristics of the fisheries is presented. These fisheries have been shown to be valuable (i.e., economically or socially important) in at least two specific ways: as a generator of commercially marketable output, and as a source of income and employment in relatively impoverished communities.

Aquaculture Asia, Vol. 8, No. 1, pp.1-58, January-March 2003

*Table of Contents* Sustainable Aquaculture Fertilization, soil and water quality management in small-scale ponds part II:Soil and water quality management S. Adhikari Fisheries and aquaculture activities in Nepal Tek Gurung Peter Edwards writes on rural aquaculture: A knowledge-base for rural aquaculture Farmers as Scientists: Commercialization of giant freshwater prawn culture in India M.C. Nandeesha Aquaculture in reservoir fed canal based irrigation systems of India – a boon for fish production K.M. Rajesh, Mridula R. Mendon, K. N. Prabhudeva and P. Arun Padiyar Research and Farming Techniques Production and grow-out of the Black-lip pearl oyster Pinctada margaritifera Idris Lane Breeding of carps using a low-cost, small-scale hatchery in Assam, India: A farmer proven technology S.K. Das Genes and Fish: Hybridisation – more trouble than its worth? Graham Mair Breeding and culture of the sea cucumber Holothuria scabra in Vietnam R. Pitt and N. D. Q. Duy The potential use of palm kernel meal in aquaculture feeds Wing-Keong Ng Using a Simple GIS model to assess development patterns of small-scale rural aquaculture in the wider environment Simon R. Bush Aquaculture fundamentals: Getting the most out of your feed Simon Wilkinson Marine finfish section Status of marine finfish aquaculture in Myanmar U Khin Kolay Regional training course on grouper hatchery production Aquatic Animal Health Advice on aquatic animal health care: Problems in Penaeus monodon culture in low salinity areas Pornlerd Chanratchakool

Florida's hydrogeologic environment

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