The ecosystem of the Halda river, the major breeding ground for sweet water carps in the country, is now under threat due to two rubber dams constructed in the upstream of the river, said experts yesterday.
They made the observation at a press conference organised by the Halda River Protection Committee at the Chittagong Press Club auditorium in the port city.
They said different man-made hazards like construction of rubber dams, unplanned sluice gates, and widespread extraction of sand using dredgers were leaving an impact on flora and fauna of the river.
“As the river is running dry, the production of phytoplankton and zooplankton, which are the main sources of food for the mother fish species, is being obstructed and the biodiversity is being affected”, said Halda expert Monzoorul Kibria, also an associate professor of Chittagong University.
All projects of irrigation and extraction of water should be restricted before measuring the total volume of water of the river, said speakers, stressing the need for increasing water flow in the upstream to save the river from salinity.
They also urged the authorities concerned to find alternative sources of water for irrigation purposes like preserving rainwater in other water bodies.
General Secretary of the committee Mohammad Ali, Karnaphuli researcher Prof Idris Ali, and East Delta University Vice-Chancellor Prof Md Sikandar Khan also spoke.
Mentionable, 19 branch canals and 17 hilly fountains are the main sources of water of the Halda.
In 2011, a rubber dam was constructed on the river at Bhujpur next to the tea garden area of Fatikchhari upazila in Chittagong, while another rubber dam was constructed at Haruyalchhari canal, one of the main sources of water of the river, by the Local Government Engineering Department in 2012.