39 resultados para green lacewings
em Aquatic Commons
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The Green Swamp area in central Florida is another area where man is developing agricultural land from marginal land. Though the area is by no means as extensive as that of the Everglades, the present efforts for its development are similar to the early efforts for developing the Everglades in that many miles of canals and ditches have been constructed to improve the drainage. Lest the early mistakes of the Everglades be repeated, the Florida Department of Water Resources considered that an appraisal of the physical and hydrologic features of the area was needed to determine the broad effects of draining and developing the swamp. This reconnaissance provides information required by the State of Florida for determining its responsibility and policy in regard to the Green Swamp area and for formulating future plans for water management of the area. Some of the features that have been determined are: the amount of rainfall on the area; the pattern of surfacewater drainage; the amount and direction of surface-water runoff; the direction of ground-water movement; the interrelationship of rainfall, surface water, and ground water; the effects of improved drainage facilities'; and the effects of the hydrologic environment on the chemical quality of water of the area.(PDF contains 106 pages.)
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(2 page flyer)
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All abalones belong to the genus Haliotis sensu latu, family Haliotidae. The 75 species known worldwide (Booloot ian et, al. 1962) are anatomically similar and all are adapted for attachment to hard substrates. Seven species are widely distributed along the coast of California (Cox 1962; Mottet 19781, of which several are important in the comercial and sport fisheries of the Pacific Southwest. (PDF has 19 pages.)
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In the Cayman Islands we are enriched with a wonderful natural environment. In this Green Guide to our Marine Environment we hope to show you how all of our lives on these three magical islands are intimately connected to the land and the sea that surrounds it. Like many of our Caribbean neighbours, a large proportion of our economy depends on reef-based fishing, diving and tourism. The beauty of our coral reefs, our beaches and our lagoons is that it is part of our heritage, and it draws many thousands of overseas visitors to our shores. It is our responsibility, as stakeholders sharing this beautiful environment, to do what we can to minimise our impact upon it. Ogier has sponsored the Green Guide, and through this publication, is helping us to preserve our natural and cultural heritage.... [PDF contains 32 pages]
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This Green Guide provides a brief summary of the alarming evidence of changing climate in the Cayman Islands. As we illustrated in our first Green Guide (2008), our lives on these three magical islands are intimately connected to the land and the surrounding sea. Our economy depends on keeping our islands healthy, because our coral reefs, our beaches, our natural heritage, all draw many thousands of overseas visitors to our shores. It is our responsibility, as stakeholders sharing this beautiful environment, to do what we can to minimise our impact upon it... [PDF contains 32 pages]
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Sources of fish and fishery products in Nigeria were reviewed. The problems of various agencies involved in freshwater fish production in Nigeria were also analysed, such problems included shortage of manpower, inadequate training for personnel, shortage of funds, lack of infrastructures, among others
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Lake Chad fisheries contributes about 13% of all fish produced by the inland and coastal states of the nation and supports a large population of fishermen and allied workers. The species of freshwater fish produced from the Lake such as Gymnarchus, Clarias and Heterotis are very popular with the fish consumers in Nigeria; hence Lake Chad processed fish is transported long distances to southern Nigerian markets. Lake Chad thus contributes significantly to the provision of fish protein and to the Green Revolution Programme
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A study was embarked upon with the twin objectives of reviewing the Green Revolution Strategy for accelerating fish production in the country and proposing an alternative strategy, a private sector approach. Some of the programmes listed in the Green Revolution are very necessary for developing a viable - fish farming industry and that money spent under such programmes is money well spent. Programmes that are also desirable but need to be considerably expanded were identified. Other programmes have been criticised on the grounds that the method chosen to achieve the desired objectives is fraught with dangers if sufficiently long run view of fisheries development is taken
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Polyculture, as presently practiced in Nigeria, focuses interest mainly on finfish. This practice, apart from neglecting indigenous valuable species such as clams and water snails, does not make full use of existing biomass. This paper suggests possible deviations from normal practice. Inclusion of macroinvertebrates in a polyculture system and stocking, temporary bodies of water with seasonal species such as the fresh water crayfish are suggested. A final suggestion is to develop a polyculture of swamp rice and crayfish
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The aim of this study was to examine areas in which fishermen cooperatives can become involved and then suggest operational guidelines in order to increase fishermen income and also to make the Green Revolution Programme a success through increased production of fish. The paper enumerated different areas in which fishermen cooperatives can participate. These include: thrift and credits, thrift and savings, consumers and building cooperative societies. It is the belief of the author that the expansion of fishermen cooperatives into the areas mentioned in this paper can enable members to process and market their products more economically, buy supplies and equipment in large quantities and obtain lower cost credit
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(pdf contains 32 pages)
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A discussion is presented on the potential for fishery development in the Niger Delta region, considering engineering activities and food production potentials of the freshwater zone and immediate hinterland, the brackishwater mangrove swamps and the estuaries. An examination of current trends in the environment indicates that a possible solution to improved exploitation of the region lies in hydraulic engineering, the manipulation of environmental conditions through varying freshwater and seawater inputs so as to increase aquatic and wetland productivity
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Blue-green algae (cyanobacteria) have had a profound and unparalled impact on the aquatic environment because of the phenomenon of bloom formation. In many countries, water management is threatened with extensive and persistent noxious blooms of blue-green algae in surface and near-surface mesotrophic and eutrophic waters. In view of this, ecological and physiological factors responsible for blue-green algal dominance are discussed. The implications of cyanobacterial blooms are highlighted and recommendations made to combat this menace
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The incidence of blue-green algal blooms and surface scum-formation are certainly not new phenomena. Many British and European authors have been faithfully describing the unmistakable symptoms of blue-green algal scums for over 800 years. There is no disputing that blue-green algal toxins are extremely harmful. Three quite separate categories of compound have been separated: neurotoxins; hepatotoxins and lipopolysaccharides. There is a popular association between blue-green algae and eutrophication. Certainly the main nuisance species - of Microcystis, Anabaena and Aphanizomenon are rare in oligotrophic lakes and reservoirs. Several approaches have been proposed for the control of blue-green algae. Distinction is made between methods for discharging algae already present (eg algicides; straw bales; viruses; parasitic fungi and herbivorous ciliates), and methods for averting an anticipated abundance in the future (phosphorous control, artificial circulation etc).
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Many have observed the reduction of the quantity of zooplankton in the presence of water blooms. It is known that in seas zooplankton as it were avoids places of accumulation of blue-green algae. By observations on one of the tributaries of the Rybinsk reservoir - the River Shumorovka - the authors tried by simultaneous collections to trace the changes in numbers, not only of zoo- and phytoplankton but also of bacteria. The plankton was collected by quantitative nets with suitable numbers of gauze and bacteria were taken account of by the method of direct calculation on membrane filters. It can be seen that the development of blue-green algae appears as an important factor, determining not only the intensity but also the direction of the process of production of zooplankton.