Aeration and Oxygenation
The purpose of aeration or oxygenation is either to remove gases such as nitrogen (N2) and carbon dioxide (CO2) from the water, or to increase the concentration of gases such as oxygen (O2) in the water. There are several reasons for aerating and oxygenating the inlet water to a fish farm. The water may contain insufficient oxygen or too much nitro-gen or carbon dioxide. If the content of oxygen in the water is increased, the less water need be added. Too much nitrogen (super-saturation) will create gas bubble disease (diving disease) in the fish with high possibilities of mortality. Too much carbon dioxide is also toxic for the fish. Adding too much oxygen to the water will also be toxic for the fish.
Aeration or oxygenation is carried out in almost all production systems. On land-based farms and in ponds it is common to use either aeration or a com-bination of aeration and oxygenation. Recent research also shows improved production resulting from adding oxygen to cages.4During transport of fish, the addition of air or oxygen is also nessesary.
A great deal of literature is available concerning aquaculture, but the literature regarding waste-water treatment, environmental engineering and water chemistry is also a source of useful information.