Description

Abstract: In an aquaculture pond, the primary production system serves both as the basis for the natural food chain, and as a primary source of dissolved oxygen (DO). As the productivity of the pond system and the standing crop of phytoplankton increases, so does the degree of fluctuation in diel DO concentrations, water quality, and the degree of vertical stratifications of the water column. In highly turbid pond systems the rapid extinction of incident light in the surface layers results in benthic zones serving only as a net oxygen sinks, even while the surface is exposed to full sunlight and is a net oxygen source. As the standing phytoplankton crop is reduced, self shading decreases, as does total food availability and gross production of oxygen, but the stability of the system, in terms of DO fluctuations and water quality, increases. Therefore, in this respect, the trade-off in balancing the pond system is in terms of gross productive potential versus water-quality stability.