Fish Poly Culture in Domestic Wastewater Ponds: A Step Towards Protein Rrecovery and Pollution Reduction

Reclamation or recycling wastewater is an alternative to the gradual degradation of natural water resources. Reused or domestic sewage is highly loaded with nutrients, suspended solids, organic and inorganic matter, and microorganisms that provide natural food for several species of edible fishes. The effluent contains excessive nutrients which may increase the growth of aquatic plants and stimulate the production of natural food for fish. Oxidation ponds or stabilization ponds in the tropics are recognized as effective and economical units for the treatment of domestic sewage as well as biodegradable industrial wastes if managed properly. The driving force in a waste oxidation pond is solar energy utilized by active continuous photosynthesis. The action of sunlight on algae in the pond enables them to grow and rapidly consume the nutrients contained in the sewage. The algae and bacteria play an inter-dependent symbiotic role in these ponds, while the algae use the nutrients and carbon dioxide by bacterial decomposition, the bacteria make use of the oxygen liberated by the algae during photosynthesis, consequently increasing the rich natural biomass for the fishes. Updated compiled information in this review article suggests that domestic waste-water aquaculture is one of the best alternative ways to remove eutrophication as well as increase the culture of poly carps. This domestic sewage-purification cum reclamation bioprocess can be one of the cheapest methods, where natural sunlight, tropical conditions and biological parameters if managed judiciously, can be recycled and reclaimed for economically viable fish culture.