Biotechnology and Bioinformatics (1+1)

6.1.1 Characteristics of aquaculture wastewater

In aquaculture system, especially in extensive culture the primary source of nitrogen and phosphorous in the pond water is derived from metabolic waste and uneaten feed.

• Only about 30% feed N and P are retained by salmonid fed, even if they consume all of the feed fed.
• The pollutant load discharged into the environment from aquaculture systems has been calculated and found that one ton of produced fish gene rates 0.8 kg of nitrogen/day and 0.1 kg of phosphorous/day.
• In intensive shrimp culture, 11.56% nitrogen and 14.11% phosphorous of nutrient input remained in water body; 19% and 36.21% accumulated in sediment.
• Shrimp stocking densities of 30-50/m², the average harvest of 5 tons to 6 tons/crop would require 10-12 tons of feed, assuming a food conversion ratio of 2.
• However, only about 20% of the feed is incorporated into shrimp biomass, so approximately 8-10 tons of feed ends up as uneaten food and excreted matter of shrimp.