The prediction of dissolved oxygen in aquaculture ponds throughout the year is essential to the design and evaluates the potential aquaculture sites. A computer model has been developed to simulate dissolved oxygen in a fish pond. A short-term Dissolved Oxygen (DO) fluctuation of a fishpond was developed by using various simple equations and continuous measurement of DO, temperature and solar intensity. Numerical computation has been performed for a typical winter (17th of January) and summer (17th of July) days.
Results from model verification runs showed that the model performance was satisfactory with respect to aquaculture pond dissolved oxygen. The relative percentage of error (RPE) for the 24 hours of simulation was 0.2818% and the correlation coefficient between predicted and measured dissolved oxygen was 0.97. The predicted dissolved oxygen was fluctuated between -0.101 to 0.113gO2m-3lower and higher than the measured dissolved oxygen for most of the 24 hour simulation.
The predicted results indicate that DO is affected by weather variables, especially solar radiation. The dissolved oxygen (DO) values ranged from 4.4 to 8.7 g m-3, where it reached the highest value (8.7) at 17:00 h, while it reached the lowest value (4.4) at 6:00 h.
The fish growth model results indicated that the total cycle time between the stocking and the harvesting is about 180-190 days during the summer months; compared with the total cycle time in natural setting is about 210-240 days.