Transportation of fish in closed systems: methods to control ammonia, carbon dioxide, pH, and bacterial growth
transportation, loading, field tests, Florida, mortality
Journal or Book Title
Transactions of the American Fisheries Society
Methods to control the development of toxic by-products in the water were evaluated for various pet-fish species enclosed in polyethylene bags overlayed with oxygen. A formula of three components was developed that decreased the concentration of ammonia and carbon dioxide, controlled bacterial growth, and maintained a higher pH compared with untreated controls held under similar conditions. Clinoptilolite at 14 g/liter controlled the ammonia accumulation, tris buffer (0.017 M) at pH 8.0 controlled the accumulation of free CO2, and neomycin sulfate at 20 mg/liter prevented bacterial blooms. Fish were held up to 48 hours and at loading densities up to 180 g/liter with favorable results. Field tests of the formulation were conducted by air-transporting several species of pet fish from either Florida or east Asia to Seattle, Washington at loading densities that averaged 102 and 87 g/liter, respectively. The average transit time from Asia was longer than shipments from Florida, 36 hours compared to 22 hours. In all test groups, the ammonia and CO2 concentrations were reduced and the pH remained higher compared with controls. However, better control occurred in the Florida tests when the transit time was shorter. In addition, mortality was reduced. The data indicated that fish can be transported at higher loading densities for longer periods of time, and can be received in better condition, when the formula is used than by current shipping practices.