Fresh Water Fish Firms:
United States has seen an increase in fresh water fish farming in states such as California, West Virginia, Florida and Kansas. Filli (25) explains that despite the surge, catfish farmers encounter wide range of problems threatening the rapid growing industry. The research paper will explore the diverse problems farmers experience and shed light on possible solutions to counter the challenges.
According to Fish Farming in Europe: Conference Report: Prospects for Growth and the Problems (15), lack of sufficient oxygen in fish ponds is one of the most common problems facing catfish farmers in United States. The shortage as Gerhardsen and Bringsvor (91) note, cause high fish mortality rate as well as inducing disease and parasite infections. Catfish is a sensitive fish and as Gerhardsen and Bringsvor (61) explain the fish may fail to feed when oxygen levels drop to below 2 ppm. A couple of environmental conditions cause oxygen deficiency. Excessive plankton present in rearing areas such as fish ponds dissolve oxygen resulting to deficiency. Some farmers in U.S.A have adopted an undesirable high rate of feeding fish paving way for plankton growth. Fish Farming in Europe: Conference Report: Prospects for Growth and the Problems (65) observes that the algae population consumes oxygen at night leaving little for fish. The unfavorable weather such as hot, cloudy and cold rainfall conditions in some U.S regions cause oxygen shortage
Farmers usually find that the rearing areas contain species of unwanted fish such as bullhead and flathead catfish. The species as Fish Farming in Europe: Conference Report: Prospects for Growth and the Problems (45) explains often ruins the ponds. Lack of proper training to the fish farmers see some of individuals overpopulate ponds leading to growth of undesirable catfish. Habitat destruction, competition for food and nesting space also contribute to the problem. The undesirable fish as Gerhardsen and Bringsvor (31) expound consume fingerlings resulting to major losses.
Growing catfish in muddy water as Gerhardsen and Bringsvor (73) explain results to low productivity. Water infiltrated by mud has scarce natural food organisms. To ensure significant fish production ponds as Filli (25) argues should have clear water for desirable sight feeding. The problem as many farmers in West Virginia observe result to decreased fish production due to water turbidity. Muddy water as expounded by experts in aquaculture hinders production of algae an important component of food web. Farmers in Kansas State often encounter this problem as a result of strong winds causing erosion and wave action that keeps soil particles in suspension (Filli, 15). Moreover, livestock activity in some farms stir mud that is in turn carried to ponds by wind causing muddy water. Catfish feeding undertakings as Gerhardsen and Bringsvor (28) explain, cause muddy water. A couple of farmers unknowingly overpopulate ponds creating dense population, a major cause of muddy water as a result of burrowing and bottom feeding activities that stir bottom mud.
Fish diseases have plagued American aquaculture industry. Catfish fish farmers complain of ‘density’ diseases. The problem as Gerhardsen and Bringsvor (41) note is caused by overcrowding, stress and pollution in artificial environment. Catfish get affected by different pathogens resulting to death. Firms in U.s experience disease and parasite widespread. Prevalent diseases in these fish firms include kidney and urinary track disorders, Nutritional disorders, skin parasites in fish, tumors and cancers and viral infection. The diseases as Gerhardsen and Bringsvor (41) explain result in mass die offs. The ambush predator dinoflagellate cause huge fish kills. The infection is caused by excretions from the catfish encouraging concentration of dinoflagellate that is described by Filli (15) as toxic. The secretion makes fish develop bleeding lesions making skin flake off in water. In some of the aquariums the population of fish is high while the water volume is limited. The scenario as explained by Filli (35) allow communicable diseases spread easily to rest of the fish causing mass infections.
The fish ponds in some areas have improper nitrogen cycle and inappropriate aquarium plants that harms the invertebrates by favoring disease transmission. The fish in the U.S firms contract bacterial, fungal and parasitic infections resulting to mass kills (Filli, 25). Improper feeding, toxic conditions and pathogens causes stress leading to diseases infection (Gerhardsen and Bringsvor, 27). Presence of wild fish, intermediate hosts such as snails and fish eating birds complete disease organism life cycle causing large scale infections. As a result of improper training and knowledge regarding professional rearing of fish, the fish farmers introduce contaminated inputs such as food, trash and processing wastes that acts as major sources of diseases in the fish farms. Gerhardsen and Bringsvor (91) observe that imported eggs, juveniles, bloodstock and water from upstream ponds also introduces diseases in the large scale fish farm. Catfish experience stressors that lead to diseases. Poor handling of fish in the firms as Gerhardsen and Bringsvor (31) postulate causes bacterial and parasitic infection. Farmers translocate fingerlings from one pond to another without proper care leading to spread of diseases. High level of pollution introduces ammonia, predisposing fish to large number of parasites and pathogens.
Waste disposal problem
The Firms keeping catfish experience difficulties managing natural waste produced by the fish and excess feeds resulting to overabundance of nutrients in fish farming ponds. The nutrients as Gerhardsen and Bringsvor (81) argue exceed certain limits encouraging excessive algae growth as well as algal blooms. The scenario creates ecological imbalance culminating to eutrophication and depletion of oxygen in the ponds resulting to fish suffocation.
Attack by predators
A survey conducted on the current topic showed that 88.3% of U.S catfish farms were affected by predators. The statistics as Filli (65) observe pose a serious threat to catfish farming industry in America. The predators as the research revealed include snakes, crabs, frogs and human beings. Piscivorous, belted kingfisher and Osprey birds get naturally lured to fish firms causing extensive damage by consuming and wounding the invertebrates. The birds as Fish Farming in Europe: Conference Report: Prospects for Growth and the Problems (75) explain, act as hosts to parasites and infectious fish diseases. According to Filli (45), the bird predation is the major source of fish loss in American fish farms.
Most catfish farms in America depend on natural water as the main source for fish farming. A growing body of evidence reveals the unreliability of natural water sources as a result of consistent dry spell and drastic weather changes. The low rainfall in recent years has resulted in catfish productivity reduction. Previous research showed a 34% decline. Drought as Filli (35) observe has had an adverse impact on catfish aqua culture industry in U.S because reduced freshwater input in ponds raises salinity levels having a total damage in catfish production.
High weed infestation in ponds where catfish firming is carried in largescale have led to decline in production. Water lettuce, hyacinth and fern that have invaded ponds are noxious to catfish production. The vegetative growth hinder water oxygenation resulting to fish suffocation and ultimately death. The weeds acts as breeding sites for diseases and predator hideouts. According to Filli (15), dense growth, covering 25% of water surface area interfere with pond recreation threatening aquatic life. The scenario causes nighttime oxygen depletion resulting mass kills due to suffocation
Catfish according to Filli (43), is extremely sensitive to abrupt changes in water temperature. Farmers in U.S observe sudden changes in behavior after moving the fish from one pond to another (Filli, 85). A couple of fish keepers report fish kills after transferring from one body of water to another. The deaths result due to change in temperature, causing stress and ultimately death.
The blue-green algae, fungi and bacteria found in commercial catfish ponds excrete a compound that cause off-flavor. As Filli (20) explains the problem occur most in late summer, causing high water temperatures. The toxic off-flavor compounds induce stress and can potentially lead to death of fish.
Harmful ecological out-come
Catfish farming as Filli (21) notes lead to environmental degradation. The harmful ecological outcome include biological pollution, fish for fish feeds, organic pollution and eutrophication, chemical pollution and habitat modification (Filli, 75). Catfish farming in United States causes extensive loss of mangrove forests as well as sanitization of soil and water affecting soil organisms.
As Gerhardsen and Bringsvor (51) explain, oxygen correction entails using mechanical aerators, gadgets that introduce oxygen rich water. Complete removal of weeds would also help restore oxygen lost as a result of consumption by plant growth. Getting rid of undesirable fish involve draining and drying ponds prior to stocking. The farmers should treat water with a fish toxicant to ensure elimination of undesirable catfish. The fresh water firms in addition should avoid using spring water, instead use well water. Gerhardsen and Bringsvor (24) explain that using turndown drain pipe prevents undesirable fish from entering the ponds. Filtering surface water through a fiber glass as well as stocking bass to predate on undesirable species minimizes undesirable fish count. According to Gerhardsen and Bringsvor (61) proper pond design, construction and maintenance of good grass cover keeps water in ponds clean and free from mud.
Removing the turbidity enhances light penetration, supporting growth of phytoplankton a natural fish food and oxygen producer. Adding materials that cause aggregation of suspended clay particles acts as a solution to mud water problem. Treating pond water with filter alum clears muddy waters. Adding organic matter as well as using agricultural gypsum to muddy ponds gets rid of clay turbidity. Gerhardsen and Bringsvor (51) expound that proper pond construction and water quality management prevents flourishing of water weeds. Phytoplankton populations in ponds creates shading effect thereby reducing weed growth. Using approved herbicides as Gerhardsen and Bringsvor (36) postulate help in aquatic weed control. Treating fish before stocking controls disease and parasite spread. Minimizing shock problem would entail raising or lowering water temperatures. The control mechanism is achieved by mixing water from the receiving pond with another from a container. Aeration as Gerhardsen and Bringsvor (21) observe helps mitigate shock effect. The appropriate solution to address predators entails using predacious insects.
Pouring oil mixture on the surface of each brood pond helps eliminate the insects and other predators. Mowing the grass around pond edges makes the region less attractive to predators such as snakes and frogs. Placing fish in an environment free of off-flavor producing organisms serves as a possible solution that controls blue green algae, fungi and bacteria (Gerhardsen and Bringsvor, 31). Holding fish in clean water for seven to ten days helps dissipate off-flavor effect. Liaising with a catfish biologist for latest treatment technologies assists greatly in minimizing off-flavor producing organisms.
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