Haunted by pollution

Halda is the only river in the country from where naturally laid carp eggs are collected for hatching. And yet, the river is being regularly polluted by industrial waste, posing a serious threat to its biodiversity.

The Halda originated at the Badnatali Hill Ranges in Ramgarh upazila in the Chattogram Hill Tracts. It flows through Fatikchhari, Hathazari and Raozan upazilas and Chandgaon Thana of the port city, and falls into the Karnaphuli.

The 81-kilometre-long river is the only natural carp breeding ground in Bangladesh, from where fertilised carp eggs are collected by local fisherman and egg collectors during April to June almost every year.

However, the ever-rampant pollution has led to 200 egg collectors losing their livelihoods.

According to a DoE report, wastes from various factories and residential blocks in Bayezid-Oxygen area are being dumped in Halda through Bamanshahi canal. Earlier, the canal used to flow directly into the Karnaphuli. But now it flows directly into Halda through Kwaish canal and the residential areas' drains.

Engine-run boats and excavation from the river are among the other major reasons behind the pollution.

DoE analysis also suggests that according to almost every parameter, the water quality of the river and the canals were found unsafe for humans as well as the aquatic life.

Meanwhile, engine-run boats are still plying on the river even after the government banned them and sand mining on the river to protect the mother fish and endangered dolphins.

Researchers claimed that the river which was once a haven for brood fish to release their eggs has seen a drastic fall in the availability of eggs belonging to the natural species as the number of brood fish coming here to lay eggs has decreased in recent years due to all the pollution.

According to Halda River Research Laboratory's data, 8,500kg eggs were collected from the river last year, whereas the number exceeded 25,000kg in 2020.

"We recommended re-excavation of Bamanshahi canal and connecting it with the Karnaphuli to protect Halda. If the pollution continues this way, Halda will become fishless in near future," said Prof Manzoorul Kibria, noted Halda researcher.

Mufidul Alam, director of DoE-Chattogram region, told this correspondent that they will take necessary action regarding this as per law.

"We are always active in protecting the biodiversity of Halda. If something is illegal is going on, actions will be taken by the administration," he said.