MODELING OF PLANKTON DEVELOPMENT PROCESSES IN THE PANGASIUS (PANGASIANODON HYPOPHTHALMUS) PRODUCTION POND IN VIETNAM

Abstract

Pangasius (Pangasianodon hypophthalmus) is a popular food in many countries around the world as well as Vietnam, at the same time, Pangasius (catfish) also brings great economic benefits from the exportation. However, unplanned catfish farming leads to environmental degradation. Fish farming is more susceptible to disease and consumes more water. Feed for fish is only partially used, the rest is released into the environment. The industrial feeds with high nutrient content, especially those rich in nitrogen (N) and phosphorous (P), are the strongest contributors to the water index. Thus, within high volume and high pollution levels of wastes from catfish pond which has had a great impact on the water environment, negatively affecting the catfish farming and the community. Modeling is a solution that helps to better control the biological processes in the pond, optimizes feed supply and water use. Modeling has many advantages compares to the real research because the cost is too expensive; requires too long time; does not affect to production or endangers to persons and equipment. In some cases, it is not possible to do experiments on real systems. Therefore, the application of the modelling is a suitable way to identify and control biological processes in catfish ponds. This research will study the plankton development processes taking place in catfish ponds by modeling using Matlab software to simulate the nutrition and development processes of fish in catfish ponds. These equations were solved by the fourth-order Runge-Kutta method and coded in the Matlab programming language.As a result, the plankton development processes of pangasius pond is simulated includes (green algae, cyanobacteria, diatoms), (the ratio of nitrogen content in green algae, cyanobacteria, diatoms), (the ratio of phosphorus content in green algae, cyanobacteria, diatoms) at different temperatures 28, 30oC.