Greenhouse gases emission from aquaculture ponds

Average emission of GHGs in g ha-1day-1 was high from traditional farming compared to scientific shrimp farming with L.vannamei and P. monodon. Global warming potential (GWP) values in Kg CO2 eq./ha/season were 91 in P.monodon farm, 218 to 351 in L.vanname i farms and 405 in pokkali shrimp farm. The GWP values increased with the increase in stocking density. These values were much lower compared to GWP values from paddy fields from Odisha (4180) and livestock in Tamil Nadu (646).

GHGs emission from aquaculture ponds varying in cultured species and intensity

*GWP was calculated per season of 4 months culture/crop (120 days)

Climate change impacts and vulnerability for aquaculture:

Based on the developed methodology and data analysis of extensive farmer’s survey (n=120) in one district each in four coastal states viz., West Bengal, Andhra Pradesh, Tamil Nadu and Kerala, shrimp aquaculture is moderately vulnerable to seasonal variations (20-40% loss) and highly vulnerable to extreme climatic events (50 to 100% loss) like floods, heavy rains and cyclone. Vulnerability assessment of aquaculture to climate change based on exposure, sensitivity and adaptive capacity indicators indicated that 4 to 19%, 37 to 66%, 1 to 34% and 9 to 43% of the aqua farmers in all the four states were under high, moderate, low and very low vulnerability categories, respectively.

Temperature variability and reproductive performance of Tiger shrimp:

At highly elevated temperature (32-33 oC) spawning and fertilization rate reduced whereas hatching rate was better at moderately higher temperature (29-30 oC) in tiger shrimps maintained in hatcheries through titanium heaterin the black circular tanks. Cellular parameters like total hemocyte count and phenoloxidase activity reduced significantly at high elevated temperature of 32-33oC. At lower temperature 26-27oC, irrespective of the algal species, the metamorphosis from one larval stage to other is delayed by 12-24 hrs compared to that at higher temperature of 29-30oC.

Back