ABSTRACT
To adapt to the emergent global climate impacts, the local communities of Khulna, Satkhira and Bagerhat districts in South-Western Bangladesh have spontaneously promoted a number of social innovation using their innovative ideas and traditional knowledge. The present study highlights on this practice called as Community Mangrove Aqua-Silvi-Culture (CMAS) to cultivate some floral and faunal species of the Sundarbans mangrove ecosystem. CMAS is a plot of swampy land with 1 to 1.5 feet deep water bordered by a dyke of 0.5 to1.5 feet height from the water level. The mangrove plant species in CMAS includes Goalpata (Nypa fruticans), Goran (Ceriops tagal), Keora (Sonnerata species), Hargoza (Alanthus ilicifolius), and Baen (Avicennia Species). Besides, there is a canal of about 2-2.5 feet depth that runs along the farm dykes where fish (Telapia, Vetki, Amadi, Tengra, Carps), shrimp (Bagda) and crabs are cultured. For in depth analysis of CMAS, face-to-face interview was conducted in 18 CMAS farms to know about the cultivation method, cost-benefit aspects, environmental and social impact of this unique culture. The farm owners opined that after 13 to 14 months of plantation, which is the shortest in comparison with traditional practice, Golpata and Goran can be harvested usually in January to February. On the other hand, farming seasonality of fish and shrimps varies species to species. However, most of the fish species can be harvested in between May to June in each year. Interestingly, CMAS culture doesn’t need much care and maintenance costs. It is expected that the detailed analysis of CMAS will help the Sundarbans depended local communities more climate resilient.
ABSTRACT
Sundarbans biosphere reserve is an ecologically important area of West Bengal, which supports a wide variety of estuarine species including Scylla serrata estuarine mudcrab of economic value. In this present study, activity of phosphatases (acid and alkaline) of hemocytes was estimated under the sublethal exposure of arsenic in controlled static water environment for 1, 2, 3, 4, 7 and 15 days of exposure. Exposure to 3 ppm of sodium arsenite for 15 days, resulted a maximum inhibition of activity of acid phosphatase (ACP) as 0.016 .M mg-1 protein min-1 with intermediate activity in different spans of exposure against the control value of 1.83 .M mg-1 protein min-1. Similar mode of maximum inhibition of activity of alkaline phosphatase (ALP) was recorded as 0.008 .M mg-1 protein min-1, when the crabs were exposed to 3 ppm of sodium arsenite for 15 days against the control value of 0.694 .M mg-1 protein min-1. Exposure to 1 ppm of sodium arsenite caused inhibition of activity of ACP which ranged from 1.76 to 0.70 .M mg-1 protein min-1. For 2 and 3 ppm of exposure activity of ACP ranged from 1.12 to 0.42 and 0.67 to 0.016 .M mg-1 protein min-1 respectively. For the activity of ALP exposure to 2 and 3 ppm of sodium arsenite yielded an inhibition of activity which ranged from 0.472 to 0.279 and 0.275 to 0.008 .M mg-1 protein min-1 respectively. Arsenic exposure resulted a dose dependent decrease in the activities of both of the phosphatases and may be considered as a suitable biomarker of aquatic pollution in Sundarbans mangrove.