Total Gas Saturation Considerations for Recirculating Aquatic Systems

Zebrafish (Danio rerio) are now widely used in aquatic research facilities for genetic and vertebrate development studies. Most of these facilities utilize recirculating systems for zebrafish production. Dependable production of high quality fish is of vital concern in these recirculation systems as these fish are valuable and in many cases irreplaceable in terms of their significance to the research being conducted. Water quality is of utmost concern in zebrafish systems. One critical parameter that has received attention in these facilities is that of total gas pressure. Under abnormal conditions, the partial pressures of dissolved gases in the water can be greater than saturation. When this is the case, there is a potential for problems with gas bubble trauma and an increasing chance for secondary microbial infections. This paper discusses total gas supersaturation theory, problems associated with supersaturation, methods of monitoring total gas pressure, and ways that gas bubble problems can be prevented in recirculating aquatic systems.