Physico-Chemical Changes in Pond Water and Bottom Sediments During Intensive Polyculture of Indian Major Carps in Cooch Behar District of West Bengal, India

The paper details the physico-chemical parameters of water and bottom sediments during intensive culture of Indian Major Carps in outdoor farmers’ ponds using diets incorporated with locally available ingredients in Cooch Behar district of West Bengal, India. The average water and soil pH ranged between 6.09–6.89 and between 4.42–4.71, respectively. The average dissolved oxygen in pond water was quite high (between 11.42–13.50 mg/l). Average electrical conductivity of the pond water and soil ranged between 0.35 -0.58 mmhos/cm and between 0.22 -0.42 mmhos/cm, respectively. The average free carbon dioxide ranged between 4.68 -6.13 mg/l, while the average total alkalinity ranged between 116.03 -119.67 mg/l in the pond water. Average Ammonium-N in the pond water ranged between 0.22 -0.77 mg/l. The average organic carbon in the bottom soil ranged from 0.98 to 1.38%, while the average total nitrogen ranged from 0.15 to 0.26%. All the ponds appeared quite suitable for aquaculture; however, the average values of water and soil pH appeared extremely acidic. Future research on temporal and spatial variations in water and bottom soil quality and its effect in augmenting production should be carried out.