Firew Admasu* and Mulugeta Wakjira
This article organized while studying PhD in Aquaculture and fishery management to review non-infectious diseases and biosecurity management of fish in aquaculture. Background: Fish diseases are broadly categorized in to infectious and non-infectious disease. Infectious diseases are caused by pathogenic organisms such as parasitic, bacterial, viral, or fungal, and non-infectious diseases are caused by environmental problems, nutritional deficiencies, or genetic cases; they are not contagious. Many of the diseasesthat occur infishare the result of stress, poor water quality, overcrowding, and failure to quarantine any new or sickfishto avoid spread ofdisease, and these factors can all be minimized by appropriate care and good hygiene. Aquaculture fish health management practices is important to preventfishdisease which begins with prevention rather thantreatment. Objectives: The main objective of this study is to assess non-infectious diseases and biosecurity management practices of fish health in aquaculture. Methods: Statistical data were collected by observation and secondary sources such as published articles like researches, reviews, books, etc and organized following the standard scientific methods. Result and conclusion: Fish pathologydeals about the cause and nature of diseases, host-pathogen relationships, diagnostic methods, therapy, epidemiology, etc. Fish diseases are caused by parasitic, bacterial, viral, fungal, environmental problems, nutritional deficiencies, and genetic cases. Fish diseases that associated with physico-chemical properties of water are non-infectious environmental diseases, and caused by adverse environmental conditions, nutritional disorders, genetic defects, results sudden mass mortality. Diseases with physical factors are mainly due to handling, transport, high stocking density and predation, and also secondary factors by pathogenic infection may introduced easily set in once injuries. Thus, fish water physico-chemical management practices in aquaculture are important to prevent such fish disease. However, affected fish symptom and diagnosis become skin darkening, swim at the surface, show respiratory distress, end of feeding, abdominal swelling, enlargement of internal organs, focal blood clots, bulging of the eyes, fading of thegills, etc. Transmitted by direct contact or close contact with surrounding contaminated water and infected fishes spreads the disease in healthy ones, viafeces,urine, sexual fluids, and external mucus. Effective prevention and control measures includes preventing infected fish movement among watersheds, reducing bird activity around aquaculture, reduce physiological stressors, good environment and adequate nutrition, etc. Treatments, no established treatment so far, however, chemotherapy, antibiotics, bath, etc are advisable. In conclusion, regularly removing contaminants from water, disinfect all equipment used for tank cleaning, administer dietary additives and immuno-stimulants are important prevention measures. If not, it cause various effects including direct mortalities, losses due to reduced growth, product quality and social factors, and costs of control measures. Therefore, prevention, strict isolation, environmental observations to ponds, including water quality, temperature, oxygen, pH, salinity, turbidity, algal blooms, evasion of overpopulation, human activity and also proper biosecurity management practices of aquaculture are basic recommended activities for controlling diseases of fishes.
Published Date: 2021-11-25; Received Date: 2021-08-22
