Characterising the air-water carbon dioxide exchange in the aquaculture ponds of east kolkata wetlands-A ramsar site

Air-water CO₂ Flux (F_aw) was measured from the point of pCO₂ (water) and pCO₂ (air) in the aquacultural ponds of East Kolkata Wetlands in three respective seasons ie, pre-monsoon, monsoon and post-monsoon. Gas Transfer Velocity was found to be 5.1 cm h⁻¹, 4.8 cm h⁻¹, 4.5 cm h⁻¹ in the three seasons respectively. pCO² (air) ranged between 391.5μatm to 398.2 μatm and pCO² (water) varied from 567.0 μatm to 2086.0 μatm throughout the study period. Total Alkalinity was observed to be the main controlling factor for exchange of CO2 between the atmosphere and water. The area was found to behave as a source for carbon dioxide during the study period showing the maximum efflux rate in pre-monsoon, 1266.78 ± 1004.74 μmol m⁻² h⁻¹ and minimum in post-monsoon, 619.0 ± 300.04 μmol m⁻² h⁻¹.