To revive a river: Taking a leaf out of Halda’s book

At its peak in 1945, the Halda River — home to the world's only natural gene bank for pure Indian carp species, including ruhi, katla, mrigal and kalibaush — produced over 136,000 kg of fish eggs. 

Fast forward to 2016, and the river experienced a drastic decline, with nearly all the fish eggs disappearing. That year, only 735 kilograms of eggs were collected.

This, however, is far from an isolated case in Bangladesh, once hailed as the "land of rivers". The widespread degradation of rivers across the country has caused severe ecological and economic setbacks, threatening biodiversities, livelihoods and the very foundation of the nation's environment.

Take the Buriganga for instance. It was once Dhaka's lifeline, but now too polluted to support aquatic life. The Turag and Shitalakshya rivers face similar challenges due to industrial waste and encroachment. 

In Chattogram, the Karnaphuli River has seen a decline in fish stocks from tannery and factory waste, while the Gorai River's reduced flow has caused salinity intrusion in the Sundarbans, threatening freshwater species. The Atrai and Dhaleshwari rivers, too, have suffered from siltation and pollution, leading to losses in fish diversity and agricultural productivity. 

Overall, according to the River and Delta Research Centre (RDRC), around 10 rivers die every year, with nearly 500 rivers lost over the past five decades.

Still, what sets Halda apart is its comeback, as it resumed hosting fish eggs again within a few years' time after 2016. While the current egg count is far lower than before, and there are occasional reports of mother fish and dolphins dying in the river, Halda has proven that with the right measures in place, a recovery from even the most critical situations is possible.

The person who really pushed this belief is Dr Manzoorul Kibria, a professor of Zoology at Chittagong University and the head of the Halda River Research Laboratory — the first research centre in the country to focus entirely on one river.

Dr Manzoorul Kibria. Sketch: TBS

Because of his huge role in bringing Halda back from the brink, Dr Kibria was awarded the Best River Scientist Award 2024 at the 3rd International River Congress in November 2024, which took place at the University of Kelaniya in Sri Lanka.

Now, as the interim government pushes for river conservation across the country, Dr Kibria suggests they take a leaf out of Halda's book. He believes a more integrated approach, involving multiple stakeholders, is key to successfully managing and protecting these vital water bodies in the long term.

"We taught school and madrasa students about how vital the river is for fish breeding, and imams from nearby mosques helped encourage the community to protect the river's resources. This [community engagement] is how you can go about saving a river. It's something you can't do alone."

Dr Manzoorul Kibria, head, Halda River Research Laboratory

He argues that the lack of coordination — or, in some cases, the complete absence of collaboration — among stakeholders is a key reason for the failure of most of the country's conservation efforts. 

For instance, the Local Government Engineering Department (LGED) focuses on infrastructure development, the Water Transport Authority (WTA) manages waterway operations, the Ministry of Environment oversees pollution control, the Ministry of Agriculture handles irrigation, and the Roads and Highways Department prioritises infrastructure projects.

"But the efforts these entities make to conserve rivers vary from one to another, which means no good result can ultimately come from them," Dr Kibria shared.

However, in the case of Halda River, the story was different.

Since 2018, a comprehensive set of conservation measures have been implemented to address overfishing, industrial pollution, and other pollutants like tobacco farming. Led by government agencies, NGOs and civil society, these efforts have successfully allowed fish to breed in Halda's waters once again. In 2020, the river was even declared a fish heritage site.

So, what did Halda do differently?

A 2019 report from the Department of Environment revealed that large factories and a housing estate were polluting the Halda River, causing fish die-offs. About 20 to 25 factories, including a tannery, dyeing plant, paper mill and a power generation plant, were situated along the riverbanks.

"Subsequently, two major polluting factories — Asian Paper Mills and the 100MW peaking power plant — were shut down entirely, which led to a 50% reduction in pollution," Dr Kibria explained.

In another study, co-authored by Dr Kibria, the crucial role of local communities in sustaining the river was highlighted, with many depending on the Halda for their livelihoods. The study pointed out the depletion of natural resources due to illegal brood fish catching and overfishing, and recommended that policymakers and planners give priority to local knowledge and experience. 

Following this, the Halda River conservation project succeeded in engaging local communities, particularly those living along the riverbanks and reliant on the river for their livelihoods. Fishermen were hired as guards along a 20-kilometre stretch of the river, from Sartar Khal to Kalurghat, to protect the breeding grounds from indiscriminate fishing.

"These people understand the importance of Halda better than anyone else. Their genuine commitment made a huge difference in our conservation efforts," Dr Kibria said. 

He added that this initiative showed how thorough research on a key issue can greatly help conservation by identifying key areas, pinpointing potential allies, and determining the exact actions needed for success.

Another vital aspect of the conservation work was getting local farmers to stop growing tobacco along the riverbanks, which had been damaging the ecosystem. Working together with the farmers, they introduced alternative crops like papaya, Nagpuri oranges, rambutan, and dragon fruit.

"Seedlings and seeds were also provided to farmers so that they could shift to more sustainable crops. This ensured that their livelihoods were supported without compromising the river's health," Dr Kibria explained. 

He then pointed out how local students and religious leaders got involved in raising awareness about the importance of Halda. "We taught school and madrasa students about how vital the river is for fish breeding, and imams from nearby mosques helped encourage the community to protect the river's resources."

The media also played a key role in spreading the word and supporting research. Journalists worked closely with researchers, letting them know whenever dolphins or other aquatic species were found dead. This helped researchers perform post-mortems to figure out the causes and take action to prevent similar problems in the future.

"This is how you can go about saving a river. It's something you can't do alone," Dr Kibria concluded.