Fish Hatchery Management - fisheries & aquaculture

HAICHERYREQUTREMENTSl7control generally is considered in recycle systems with supplemental makeupwater or with egg incubation systems where small quantities of waterare required. A number of heat exchange systems are available commerciallyfor heating or chilling water.AERATIONWater from springs and wells may carry noxious gases and be deficient inoxygen; lake and river sources also may have low dissolved oxygen contents.Toxic gases can be voided and oxygen regained if the water ismechanically agitated or run over a series of baffles.STERILIZATIONAny water that has contained wild fish should be sterilized before itreaches hatchery stocks. Pathogens may be killed by chemical oxidants orby a combination of sand filtration (Fieure 5) and ultraviolet radiation.BACKWASH TROUGHSFILTER TANKBAC KWASHOU T FLOWGRAVELLARGE STONESPERFORATED LATERALSFILTER FLOORFtcuRE 5.COLLECTION MAIN FOR CLEAN WATERDISCHARGE ANO BACKWASH INFLOWDiagram of a sand filter. The water supply is clarified as it flowsdown through the sand and gravel bed, and is then collected in the perforatedlateral pipes and discharged from the filter. The filter is backwashed to clean itby pumping water up through the gravel and sand; the collected waste materialis washed out the backwash outflow.