Aquaculture Ponds

Since the most significant positive value (P) of the above formula is dependent on light conditions (the photosynthesis can take place only by utilization of solar energy), the dissolved oxygen content of the fish pond varies over a period of 24 hours.

Figure 1 shows a typical daily change of oxygen concertation of a fish pond. the photosynthesis starts gradually from the early morning hours while the dissolved oxygen content of the water is increasing. The maximum value, in several cases much higher than the saturation level, can be observed early in the afternoon.

From the late afternoon hours photosynthesis is rapidly decreasing is stopped after dark. The dissolved oxygen content of the water is also decreasing during this period. the minimum value occurring during the summer months.

Figure 1. Diurnal change of the dissolved oxygen concertation in intensive FISH POND.

Factors Influencing the Dissolved Oxygen Content of Pond Water

The DO levels of fish ponds are influenced by several factors, viz. Production of macro and microorganisms in the water, Oxygen consumption by pond water. Oxygen consumption by the pond bottom, Oxygen consumption by fish, Natural diffusion caused by wind action and Artificial control of the dissolved oxygen content of water.

Artificial control of the dissolved oxygen content of water

Artificial control of the oxygen budget of water of fish ponds in this case means technical and practical measures which have direct effect on the dissolved oxygen content of the pond water.

Oxygen content of the pond water can be influenced by two methods; by change of flow rate, and by aeration of pond water.