Fish farms

Direct Uses of Geopressured Fluids. Many of the uses typical of hydrothermal energy, such as greenhouse, fish farm, and space heating, have been proposed for geopressured resources, but none has been commercially developed (34). Hydrothermal fluids are widely used in enhanced oil recovery, however, to increase production from depleted oil fields. 

Oxygen, when introduced into fish-farming ponds and pools, particularly trout pools, enables these fish to increase their food intake and hence grow more rapidly (see Aquaculture chemicals). Fermentation operations are accelerated by sparging with oxygen (see Aeration,biotechnology Ferl ntation). 

The nature of the conditions of intensive production, however, can increase the risk of diseases and infections which can spread very rapidly and devastate large numbers of animals." Thus it is common practice for producers of poultry to add coccidiostats to their diets and vaccines to their drinking water in order to prevent coccidiosis and other infectious diseases such as bronchitis and Newcastle disease. A similar problem exists for intensively reared fish, where it is necessary to add antibiotics to their diets. A problem with intensively reared fish is that their diet is added directly into the water in which they live thus drugs and other additives in the diet are relatively easily dispersed into the local environment of fish farms, where they can increase bacterial resistance and also cause problems such as algal blooms. 

Polyculture Fish farming in which 2 or more compatible or symbiotic species of fish are grown together. Also known as Multiculture. 

Direct geothermal energy is used for space heating of homes, greenhouses, livestock barns, and fish-farm ponds. As well, it is employed as a heat source in some industrial processes, such as paper production in New Zealand and diying diatomite in Iceland. Since the industrial applications usually require high-... 

Geomembrane These liners chiefly provide impermeable barriers. They can be characterized as (1) solid waste containment hazardous landfill, landfill capping, and sanitary landfill (2) liquid containment canal, chemical/brine pond, earthen dam, fish farm, river/coastal bank, waste-water, and recreation (3) mining, leach pad and tailing ponds and (4) specialties floating reservoir caps, secondary containment, tunnel, erosion, vapor barrier, and water purification. Plastics used include medium to very low density PE, PVC, and chlorosulfonated PE (CSPE). (The Romans used in their land and road constructions what we call geomembrane.)... 

Large quantities of pharmacologically active substances are used annually in human medicine for diagnosis, treatment, and prevention of illness or to avoid unwanted pregnancy. In animal and fish farming, drugs are mostly adminis-... 

Detected in molluscs and wild fish in Norway 189-285 mg L 1 in sediments in fish farming [26]... 

A 250 kilowatt system is planned for a site in Norway. The system will be operated by Norske Shell to demonstrate that CO2 can be economically recovered. The CO2 recovery technology is being developed by Shell Hydrogen. The CO2 could be sequestered in underground reservoirs or could be used for special applications such as fish farms or agricultural greenhouses. The test system will be sited at a fish hatchery. The system is expected to begin operation in early 2003. 

Another important source of antibiotics in human diet is through the ingestion of farmed fish. Farmed fish and shrimp are produced in crowded facilities with inadequate or nonexistent regulation of antibiotic use. The detection of chloramphenicol... 

Ishida Y, Ahmed AM, Mahfouz NB et al (2010) Molecular analysis of antimicrobial resistance in gram-negative bacteria isolated from fish farms in Egypt. J Vet Med Sci 72(6) 727-734... 

Aquaculture is another means of meeting the demand for fishery products. This method, however, is rather costly in developed nations, although many countries have practiced some form of aquaculture for many years. China practiced fish farming as far back as 2000 B.C., but it was introduced only recently in Africa where about 700,000 tons are produced annually. Fish farming has maintained its importance through the centuries in Russia, which today produces about 200,000 tons of pond fish (17). 

Hansen P.K., B.T. Lunestad, and O.B. Samuelsen (1992). Effects of ox3rtetracycUne, oxaUnc acid, and flumequine on bacteria in an artificial marine fish farm. Canadian Journal of Microbiology 39 1307-1312. 

Samuelson O.B. (1994). Degradation of ox)4etracylcine in seawater at two different temperatures and light intensities, and the persistence of oxytetracycline in the sediment from a fish farm. Aquaculture 83 7-16. 

Samuelsen O.B., V. Torsvik, and A. Ervik (1992). Long-range changes in ox)4etracycline concentration and bacterial resistance toward oxytetracycline in a fish farm sediment after medication. Science of the Total Environment 114 25-36. 

Water sample from a fish farm n.d. Threshold effect 500 ml/1... 

The residue depletion profile of flumequine in uout seems to be quite similar to that in the sea bass (174). When flumequine was administered to seabass as a mixture with the feed at a dosage of 12 mg/kg bw for 5 days, residues of flumequine in muscle tissue could be detected by 36 h after the last treatment. The relatively high temperature of the sea water (21-25.3 C) in this study was suggested as the primary factor determining the rapid depletion of residues from the fish tissue. In another study (175), flumequine disappeared from muscle of sea bream at 240 h after the end of treatment, but showed a longer depletion rate from skin and vertebrae that behaved in fact as reservoir tissues. Much slower depletion profiles have been reported in studies carried out with Atlantic salmon (158, 170, 176), rainbow trout (177), and some wild fish caught in the vicinity of fish farms such as saithe and cod (178). 

Oxytetracycline is also one of the most frequently used antibiotics in fish farming. Oxytetracycline residues exceeding the 0.1 ppm tolerance level were detected in raw catfish fillets 18 h after oral administration at a dosage of 37.5, 75, or 150 mg/kg fish for 10 days (238). Residues were highest in liver, followed by muscle, plasma, and kidney. Drug excretion was temperature dependent higher residue levels could be detected at lower temperatures. In rainbow trout... 

The red tide alga Prymnesium parvum poses a serious threat to fish farming. Prymnesin-2 (184) (CggHnsC NC ), the major toxin of the phytoflagellate, shows potent hemolytic and ichthyotoxic properties. The minimum concentration to cause hemolysis of a 1% mouse blood cell suspension and to kill fresh water fish, Tanichthys albonubes, is 3 nM [145]. 

Ozone is more popular than chlorine for municipal drinking water in some western European countries, where it has been used for more than 80 years. It is widely used in indoor swimming pools and spas, and also in industry, such as fish farming, fruit and vegetable wash water, waste treatment, and chemical processes. 

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