Fish Hatchery Management - fisheries & aquaculture

HATCHERY REqUIREMENTS 51Table 6 summarizes some of the characteristics of the various rearinsunits that have been described.Bio logica I Design CriteriaEvery species of fish has basic environmental requirements and each hasoptimum conditions under which it thrives and can be efficiently cultured.Biological criteria are essential in the design of any fish culture facility andthese criteria must be recognized before a successful fish rearing programcan be developed. The following comments are abstracted fromNightingale (1976).Information required in designing a facility includes fishery managementneeds, fish physiology, chemical requirements, disease, nutrition, behavior,genetics, and fish handling and transportation.These criteria must be developed for each species to be cultured. Thefishery management criteria include identification of the species to bereared, desired sizes for production, and desired production dates. Managementcriteria are usually listed as the number and length (or weight) of fishthat are required on certain dates. Physiological criteria include oxygenconsumption for various fish sizes and optimum temperatures forbroodstock holding, egg incubation, and rearing. Required rearing space,water flows, and spawning and incubation methods are included in thesecriteria. Chemical criteria include water quality characteristics that affectthe species of fish to be reared, such as tolerable gas saturation, pH, andwater hardness. Disease criteria include methods for disease prevention andtreatment. Nutrition criteria involve the types of feeds, feeding rates, andexpected food conversions at different temperatures and fish sizes.Behavior criteria are needed to identify special problems such as cannibalismand excessive excitability; for example, a decision may be made to useautomatic feeders to avoid a fright response. Genetic criteria involveselection of specific strains and matching of stocks to the environment.Transportation and handling criteria involve the acceptable procedures andlimitations for handling and moving the fish.The application of these criteria to the particular circumstances at eachhatchery can result in a biologically sound culture program. A program canbe developed by combining the management and physiological criteriawith the particular species and water temperatures to be utilized. Rearingspace and water flow requirements can be defined and combined with theother criteria to establish a suitable hatchery design.Good program development for fish hatchery design should include, inaddition to biological criteria, adequate site evaluation, production alternatives,and layout and cost estimates.