The fish died due to low level of dissolved oxygen and exceedingly high level of ammonia which contaminated the river water
Hundreds of dead fish floating in the Halda River represents a dire warning and requires the immediate attention of the government, according to the Halda River Protection Committee which organized a press conference about the current scenario of the Halda River, at the Chittagong Press Club Friday.
At least 20 species of fish and aquatic animals, including two species of prawn were found floating in the river due to massive industrial pollution.
A great number of fishes such as catfish or carp that lives in deep water were found dead on June 21 and 22, floating on the river. Halda River is known as the country’s largest natural breeding ground for carps.
The committee points out the causes of the disaster and ways to restore the river from man-made pollutions.
President of Halda River Protection Committee Prof Dr ManzoorulKibria chaired the program while it was addressed by Shamshul Haque Haidari, Md Ali, Chowdhury Farid, Amin Munna and Reza Mozammel of the Halda River Protection Committee, among others.
During the press conference, researcher Dr Manzoorul warned that the brief spell of massive pollution, for which a great number of fish died, would take a long term toll on the river.
“Although we have been conducting research on the river for a long time, we are not familiar with such type of disaster,” he said.
Dr Manzoorul further added: “On behalf of Halda River Research Laboratory of Chittagong University and Halda River Protection Committee, we have collected water and dead fish samples from different points of the river and tried to identify the source of the problem.”
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Quality of water in Halda
“After the recent disaster, water samples from 11 points of the river have been collected for lab tests,” said Dr Manzoorul.
“The level of dissolved oxygen, found in the water was very low and is not suitable for fish and other aquatic organisms to survive. Pitch dark and foul smelling water was found in Chhayar Char to Ramdas Munshir Hat areas of the river.
“The water samples tested in the lab showed that the extent of pollution was higher in the downstream of the river. The average level of dissolved oxygen was found 1.01ml per litre against the required level of at least 5ml per litre, in the eight-kilometre stretch of the river from AzimerGhat to Madunaghat area,” said Dr Manzoorul.
Dr Manzoorul also pointed out: “The level of ammonia in Khandia and Katakhali- two feeder canals of the Halda, were found to be hundred times higher than the tolerable limit. Apart from that, layers of oil were also found floating sporadically in the mouths of some feeder canals”
The fishes died due to low level of dissolved oxygen and exceedingly high levels of ammonia, which contaminated the river water.
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Industries responsible for polluting the Halda
“100MW Hathazari Peaking Power Plant and Asian Paper Mill were found to be the major industrial polluters for the Halda.The plant illegally constructed an underground pipeline to release its untreated furnace oil to the adjacent canal lined to the Halda. The power plant is yet to set up Effluent Treatment Plant (ETP),” said Dr Manzoorul.
While speaking about Asian Paper Mills Dr Manzoorul said: “The mill has set up ETP. However, it virtually turned its adjacent canal into a dumping station. The waste released by the paper mill has deposited over a stretch of two kilometres of the canal and created a 1-1.5 ft thick layer of paper mill waste.”
Dr Manzoorul pointed out about the illegal set up of many poultry farms surrounding the river and the poultry bird excreta, also responsible for the falling level of dissolved oxygen in the river.
“Chittagong Development Authority (CDA) blocked Bamanshahi canal a few years ago, for a housing project.
“Both industrial and domestic wastes are now being channelled to the Halda through Khandakia canal due to the diversion,” added Dr Manzoorul.