• 41 dead dolphins recovered from Halda in over 5 years
• DoE launches probe, report expected soon

TDS Desk:

In the span of a week, five brood fish and a dolphin have died in the Halda River, with experts attributing these unusual deaths in the natural fish breeding area primarily to four factors: river pollution, the use of poisons for fishing, chemicals from rubber dams and bacterial infections in the brood fish.

A dead catla brood fish weighing approximately 19.3kg and measuring about 118cm in length was recovered from the Azim Ghat area of Raozan, Chittagong, at around 1pm on Sunday.

Two days earlier, on June 28, two catla brood fish were found in the Kumarkhali area of Northmadarsha union in Hathazari. One weighed 10kg and measured 58cm, while the other weighed 12.5kg and measured 98cm. The first was buried as it had decomposed, while the latter was preserved at the Halda River Research Laboratory of Chittagong University for analysis by the upazila fisheries officer.

Previously, on June 26, a 10kg brood fish was discovered dead in the Bakar Ali Chowdhury Ghat area of Urkirchar union, Raozan. Locals recovered and buried the fish.

Another brood fish weighing 12kg met a similar fate just a few days earlier.

Additionally, on June 26, a dead dolphin was found floating in the river near the Sipahirghat area of Garduara union in Hathazari and recovered by Integrated Development Foundation (IDF) personnel.

Over the past five and a half years, 41 dead dolphins have been recovered from the Halda River, with the most recent recovery before this one occurring on November 3, 2022.

Shojol Banik, a resident of Urkirchar, said dolphins and brood fish often died from the impact of mechanical boat propellers.

“However, the absence of injury marks on the dead fish and dolphins suggests toxic waste from city factories, discharged into the Halda River through four canals in the Hathazari section, is poisoning the aquatic life.”

On May 7, brood fish released a limited amount of eggs in the Halda River, with collectors using about 200 boats to gather the eggs.

They managed to collect approximately 40-45kg of eggs, a significant drop from the 437kg collected in 2023.

Collectors then expected more eggs during the subsequent full moon and new moon but were disappointed when no additional eggs were found by June 25.

Experts ascribed this decline to the release of water from two rubber dams in the Fatikchhari area, Bhujpur and Harualchari, two days before the expected egg-laying period.

This release mixed with chemicals accumulated over six months into the Halda, disrupting the natural environment necessary for egg-laying.

When brood fish cannot release their eggs, they retain them in their bodies, which can lead to bacterial infections and death if the water quality is compromised.

EXPERT OPINION

Dr Md Shafiqul Islam, a Halda researcher and head of the biology department at Chittagong Cantonment Public College, said: “The health of the Halda River is under serious threat due to excessive pollution. Toxic waste is altering the physico-chemical properties of the water, polluting the aquatic environment.”

He said it was imperative to identify and implement measures against the factories dumping waste into the Halda River’s branch canal to restore the river from its current polluted state to a healthy environment.

PROBE LAUNCHED

The Department of Environment’s Chittagong metropolitan office formed a five-member investigation committee on June 23 to identify the sources of pollution in the Halda and nearby Karnaphuli River, instructing it to submit its report within 15 days.

Ashraf Uddin, a research officer at the Chittagong district office and member of the investigation committee, said he was optimistic that the investigation would be completed within the next week or the following week.