Pollution loads from aquaculture and their management
1997
Ahmad, M.
Intensification of aquaculture is a potential source of pollution to the environment. Food composition, feed conversion, usage of chemicals and the type of organisms cultured may be considered as important factors affecting biota. This paper looks into the environmental impact of tea seed, which is a chemical commonly used in shrimp ponds to eliminate fish. Tea seed, which contains around 15% saponin, was tested on cultured mirror carp (Cyprinus carpio). Twenty fish were exposed to 13 ppm tea seed. The time of LD50, oxygen consumption, haemoglobin content (Hb) and number of erythrocytes (RBC) were measured. The results showed that tea seed significantly affected the opercular beats, which increased from normal 1.5 beats to 2.5 beats per second in the first hour and then decreased slowly until the fish finally died. The Hb decreased from 72.5 to 72.3 mg/dL. But RBC increased from 1,403,333 to 2,909,000 for treated fish and from 433,333 to 1,100,000 for untreated fish in the first and eight hours respectively. LD50 was achieved within three hours of fish exposure to 13 ppm tea seed solution. From these results it can be concluded that the impact of tea seed on the environment must be controlled.
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