Fish Hatchery Management - fisheries & aquaculture

Flcuno 112. Plastic bag shipment of fish. The container should be at least 4-milplastic and preferably thicker for catfish and large sunfish. (t) fn" proper weightof fish is combined with the required amount of water. (Z) fisn then are pouredinto the plastic shipping bag. Any chemicals such as anesthetics or buffersshould be added to the water before the fish are introduced. (3) The bag is thenfilled with oxygen. All the air is first forced out of the bag, which is then refilledwith oxygen through a small hole at the top of the bag, or the bag can bebunched tightly around the oxygen hose. Approximately 75% of the volume ofthe bag should be oxygen. The bag then is heat-sealed or the top is twistedtightly and secured with a heavy-duty rubber band. (4) Because cool water cansupport more fish than warm water, the water temperature in the shipping containershould be kept as cool as the fish will tolerate. If ice is needed it may beplaced directly with the fish or in separate bags (arto*) next to the fish container.In this way the fish and water are cooled simultaneously. (S)Polyurethane foam inch thick is excellent insulation for shipping, but it isfheavier and less efficient than foam. (0) fn" package then is sealed and properlylabelled for shipment. (Photos courtesy Don Toney, Willow Beach NationalFish Hatchery, FWS.)I865