Abstract: Forecasting/prediction considering three decade baseline data on dissolved oxygen (DO) in western and central Indian Sundarbans reveals the probable occurrence of hypoxia in the aquatic system of this World Heritage site during 2050. Starting from the baseline year 1984 a decreasing trend of DO is observed irrespective of seasons and stations. The sudden rise of DO during premonsoon 2009 is the effect of Aila, a super-cyclone that hit the study area with a speed around 110 km/hr. Forecast value during 2050 premonsoon, monsoon and postmonsoon are 3.80 ppm, 6.08 ppm, 5.55 ppm respectively at Sagar South, whereas at Gosaba, the values are 3.25 ppm, 4.63 ppm and 3.85 ppm during premonsoon, monsoon and postmonsoon respectively. The overall result suggests a picture of concern as the aquatic system is gradually approaching towards hypoxia. The super-cyclone Aila caused a massive adverse impact on the salinity profile of the study area as well as on the livelihood, but a congenial situation is observed with respect to DO level in the estuarine waters.
Keywords: Forecast, dissolved oxygen (DO), hypoxia, Aila.