By Sri S.Rajamanickam
Asst.chief Technical officer,ICAR-CIBA
The common causes of white foam in the shrimp pond is excessive amounts of dissolved organic compounds in the water.
The excess dissolved organic waste can come from many sources including overfeeding, a buildup of shrimp waste, or dead plankton.
Generally, Foamy shrimp pond water is one of the indicator of plankton mortality problem.The foam continue and raising in the pond water, this condition indicating plankton mortality in the water gradually increases. The water colour is collapse suddenly and transparency, this condition indicated plankton mass mortality.
The plankton mass mortality or gradually mortality causes by
a) Unfavorable physical conditions: weather, water parameters.
b) Nutrient deficiency
c) Zooplankton predation
d) Bioluminescent microorganisms and toxicity.
Possibility quick solutions:
A simple solution to restore the water’s parameters balance and remove excess dissolved organic waste is to remove and replace about 20 percent of the water every two days until the foam disappears.In some geographical areas and in very large ponds, or amount of water needed may be unfeasable. In these situations, bio-degradation is the best method. But it is long processing method.
Prevention:
After two months culture period, maintaining & domination of chlorella green algae in the pond and avoid the short life unhealthy algae of diatoms domination.
Maintaining the nitrification and denitrificans cycle in the pond ecosystem, waste degradation in the water side with the heterotrophic probiotics application and C:N ratio maintaining.Surface scum or foam removed by dragging with fine mesh drag net (or) application of zeolite 20 kg/ acre.
