MIRZA, June 12 � The Kamrup district administration has prohibited throwing of plastic bags /materials, flowers, pulses, puffed rice (muri), gutka, shikhar etc., into the historic Bishnu Pushkar (Bishnu pond) located in front of the Sri Sri Hayagrib Madhabdev Temple at Hajo by enforcing Section 144 CrPC in the pond and its campus. This was done to prevent dying of fish in large numbers in the pond, stated a press release issued by DIPRO, Kamrup Lucky Biswas.
The Kamrup district administration has also prohibited feeding of the fish at the historic pond by (throwing) any eatables (feeds) other than the fish feed or turtle feed certified by the Fishery Department. The district administration has also prohibited sale of plastic carry bags and eatables, other than those notified by the Fishery Department, within 50 metres from the periphery of the historic pond.
Official sources said that large-scale death of fish (including calbasu, catla, cheni puthi, grass carp etc) had occurred in the historic Bishnu Puskar in Hajo, a few days back. The death of the fish in the pond was found to have been caused by the depletion of oxygen in the water of the pond, which is, in turn, caused by the decomposition of organic matters at the bottom of the pond, consisting of plastic materials (bags etc), pulses, flowers, puffed rice (muri) etc which are thrown into the pond by the devotees and also shikhar and gutka by the public.
According to a Fishery Extension Officer (FEO), Ranjit Sarma, who is also monitoring the development at the Bishnu Pushkar, fish cannot survive if the dissolved oxygen level goes down to less than 3 mg per litre and said that the death of the fish had occurred a few days back due to the fact that the dissolved oxygen was found to be only 1-2 mg per litre (1-2 ppm).
Sources said that pollution of water of the pond was contributed by the emission of some toxic gases like sulphur, ammonia from the bottom (bed) of the pond. Plastic materials, pulses, puffed rice, flowers have also decomposed in the bed of the pond resulting in contamination of the water.
Fishery officials said that continuous rains in the last few days has also prevented photosynthesis in the pond. Water pollution and decomposed materials have also prevented penetration of sunlight into water resulting in poor photosynthesis. Poor photosynthesis, in turn, has resulted in depletion of the oxygen composition in the water pond resulting in the death of the fishes.
Ranjit Sarma said that water of the pond has been treated with different medicines and now the amount of dissolved oxygen and the ph of water was normal for the last few days and no fresh deaths have occurred so far.
�The average dissolved oxygen in the water of the pond was measured at 8.8 mg per litre and the ph was 8.5 on June 11 which is quite normal and if such a trend continues, fishes will not die. The present treatment of water is only a temporary solution. The oxygen and the ph level may go down if there is an earthquake (a earthquake will lead to emission of toxic gases from the bed of the pond) or if rain continues to pour down uninterrupted for several days,� Sarma said.
When asked to comment on a permanent solution to the death of fish and tortoises in the historic pond, Sarma said that present depth of the water in the pond is 30-40 feet and sunlight cannot penetrate to the bottom of the pond. Hence, the depth of the water level needs to be minimised to 10-12 feet by dewatering of the pond and there should be outlets at the pond for removing excessive water. Excessive mud, which contains a large number of toxic materials now, has to be removed from the pond.
Swizen Bharali, a member of the Sri Sri Hayagrib Madhab Temple Committee, said that there was a permanent outlet in the pond since its formation, but the natural outlet was closed in 2007 due to which excess water of the pond cannot come out of the pond now. He requested the Kamrup district administration to launch immediate plans for dewatering and removing the mud from the pond and restore the old outlet of the pond for maintaining the necessary depth of the water level in the pond for the survival of the fishes.
Bharali said that the large-scale death of tortoises had also occurred in the pond three years back alongwith the death of the fishes. He said that the pond is home to more than 12 species of tortoises, including the tricarinate hill turtle, Indian tent turtle, elongated tortoise, Indian softshell, brown roofed turtle, Indian roofed turtle, Indian flapshell, peacock softshell, Assam roofed turtle, spotted pond turtle, narrow headed softshell turtle and black softshell turtle etc.
A member of the Sri Sri Hayagrib Madhab Temple Committee said, on the condition of anonymity, that turtles come out during the night to the bank of the pond for breeding and other purposes and that they find it difficult to walk through the stone pitched slopes of the pond and some of them also get minor injuries due to friction with the stones. He said that the stone pitching at the slope of the pond also needs to be examined as to whether it is causing inconvenience to the tortoises or not.