These new ponds can be seeded with phytoplankton through such sources as wading birds, turtles, and wind-blown spores. Many species of phytoplankton will reach a new pond, but only certain ones will survive and flourish. The species that colonizes the new pond depends upon the suitability of the environment for growth and, to some respect, chance. Water Quality Phytoplankton, more than any other organism, directly affect a number of critical water quality variables in commercial catfish ponds. The phytoplankton community drives the dissolved oxygen, carbon dioxide and pH cycles and directly affects the concentration of nitrogenous water products such as ammonia and nitrite.
Phytoplankton produce oxygen during photosynthesis.
The oxygen is then released into the water. Dissolved oxygen concentrations reach their highest concentrations in the late afternoon. The carbon dioxide cycle is the opposite of that of oxygen. Phytoplankton take up carbon dioxide during the light hours for photosynthesis. The total amount of photosynthesis in the pond overshadows the total pond respiration during the day.