Assessment of water quality parameters in grow out phase of brackish water fish Lates calcarifer (Seabass) in floating net cages

Cage culture is an alternative to inland and brakishwater farming, whereby existing water resources are used to increase fish and shell fish production and the fish are enclosed in a cage allowing the water to pass freely between the fish in the sea. The mesh retains the fish, making it easier to feed, observe and harvest them. The mesh also allows the water to pass freely between the fish and surrounding water resource, thus maintaining good water quality and removing wastes. The present studies were conducted in the closed bay near Suryalanka, Baptla, Guntur district. Prior to start of the experiment, the transported fish were acclimated with the sea environment by rearing them in hapa net for one week. Fish with an average initial weight of 351.72±1.05g were randomly stocked in the net cages at 6fish/ m3, 8fish /m3, 10fish /m3, 12 fish/ m3. Standard methods (APHA) used for analysis of water quality. All important water quality parameters was analysed for a period of 90 days with 15 days interval. The growth parameter of fishes from each net cage were estimated by taking the individual body length and weight at every 15 days of interval. This paper gives detailed information on water quality parameters such as water temperature, pH, dissolved oxygen, total alkalinity, nitrite, nitrate, ammonia in brackish water fish culture in floating net cages.