- Kaptai Lake is one of Bangladesh’s largest inland fish hubs, supporting the livelihoods of more than 27,000 registered fishers in the Chittagong Hill Tracts.
- Over the past several years, catches of high value carp fishes have declined sharply, forcing many small-scale fishers to abandon or supplement the ancestral profession.
- Researchers said carp species depend on specific spawning conditions including suitable breeding grounds. But the lake’s major breeding areas have been degraded, while overharvesting has further reduced the chances of natural recovery.
- Experts warn that without restoring breeding grounds, increasing carp fry stocking and improving fisheries management, the decline could continue, which would deepen economic pressure on small-scale fishers.
A faded towel draped over his shoulders, 53-year-old Khokon Jaladas sat quietly in the yard of his home. Just beyond his house, a few fishing boats moored in Kaptai Lake, the largest manmade reservoir in Bangladesh. He watched them quietly.
Until a few years ago, he would have been out on the water too, spending long hours casting nets and trying to catch enough fish to feed his family. But now, fishing alone is no longer enough for him. To make ends meet, he works as a laborer in the boat building sector while continuing to fish whenever he can.
“There used to be plenty of carp fish. We could catch fish easily and earned Tk 1200 ($10) to 1600 ($13) per day. But now, catches of high-value carp species dwindled,” Khokon said from Old Jelepara, a settlement on the edge of the lake in Rangamati district’s Sadar upazila (sub-district).
“Sometimes, I return home empty handed from the lake. For this, it would be difficult to support my six-member family without doing other work,” Khokon said. Around Kaptai Lake, Khokon’s story is becoming far too common.
For generations, the fishers met their livelihoods catching high-value carp species. As these fish become harder to find, many have no choice but to leave the profession.
Created by a hydroelectric dam on the Karnaphuli River in 1960, the Kaptai Lake is one of Bangladesh’s most important hubs of inland fisheries.
Declining carps means less income
In Rangamati’s fish landing station, baskets of small fish like kachki (Corica soborna) and chapila (Gudusia chapra) are unloaded throughout the morning, where large carp species including rohu (Labeo Rohita), catla (Labeo catla), and mrigal (Cirrhinus mrigala) that once defined the lake’s fishery are increasingly difficult to find. Traders were also seen categorizing fish into piles destined for markets across the country, mainly for Dhaka and Chittagong.
“Several years ago, you would see carp fish everywhere. Now most of what arrives here is small fish,” said Sukanta Das, director of the Kaptai Lake Fisheries Society Limited.
Government data on fish catching also reflects the decline of carp.
According to the Department of Fisheries, catches of indigenous carp species — including rohu, catla, mrigal and kalibaus (Labeo calbasu) — from Kaptai Lake fell from 422 tons in the 2001-02 fiscal year to just 22 tons in 2024-25.
Yet, overall fish production in the lake moved in the opposite direction, rising from 7,247 tons to 20,631 tons over the same period.
But fishers and traders said their incomes have fallen despite rising fish production.
“People see more fish arriving at the landing station and assume the fishery is doing well. But most of that increase comes from low-value small fish. For instance, a few baskets of carp used to earn more than a huge catch of small fish. The volume has gone up, but the money hasn’t. So, this shift has reduced earnings for both traders and fishers,” trader Sukanta Das said.
Importance of fishes from Kaptai Lake
According to the Department of Fisheries, Bangladesh produced about 1.4 million tons (1,436,070) tons of fish from inland open waters in fiscal year 2024-25. Of that, Kaptai Lake contributed 20,631 tons, accounting for about 1.44% of the country’s total inland open-water fish production.
“Kaptai Lake fish are open-water fish. Unlike farmed fish, they are not confined to a small area and do not depend primarily on artificial feed. They swim freely, forage naturally and grow within a complex ecosystem,” said Mohammed Shahidul Alam (Shaheen), associate professor of the fisheries department at the University of Chittagong.
“That natural lifestyle is reflected in the taste of the fish. Consumers often find them more flavorful, and nutritionally, they remain an important source of quality protein. This is one of the reasons why fish from Kaptai Lake continue to enjoy strong demand in the market despite declining catches,” he added.
“Carp species require specific spawning conditions such as suitable breeding grounds; monsoon flows and favorable water condition, which are now largely absent in the lake. Lake’s four major breeding grounds have been lost to siltation, while overharvesting has further reduced the chance of natural recovery,” said Ishtiak Haider, senior scientist and head of the Bangladesh Fisheries Research Institute’s (BFRI) Rangamati unit.
He also said smaller fish reproduce faster and need less specific conditions than carp and can adapt more easily to changing conditions, which is why they are increasing.
Struggling to stay afloat
Covering an area of about 68,800 hectares (170,000 acres), the reservoir primarily supports artisanal and medium-scale fishers who make a living for their families by fishing in the lake, according to a 2024 study.
Per the National Fishermen’s Association, 27,000 fishers are registered to catch fishes from the lake.
Another study found that fishers in the lake use three types of boats and 16 types of fishing nets. Of them, the most commonly used are the vasa jal (large-mesh gill net) and kachki jal (fine-mesh seine net).
A vasa jal is set in a fixed location and catches fish as they move through the water. In contrast, a kachki jal is dragged across a section of the lake, sweeping up fish in its path.
As catches of small fish have increased, many fishers said the kachki jal has become more profitable. But buying one is beyond the means of most small-scale fishers.
Depending on its size, a kachki jal can cost between Tk200,000 ($1,667) to Tk600,000 ($5,000), compared to Tk 20000 ($167) to Tk60000 ($500) for a vasa jal.
Meanwhile, the shift is supporting those who are able to invest in expensive kachki jal, which is more capable of catching all types of fishes. The result is a widening divide between small-scale fishers and large operators.
According to the National Fishermen’s Association, more than 1,000 kachki jal are operating in the lake.
Many registered fishers, who once worked independently, now earn wages as workers on boats owned by large scale operators as their vasa jals no longer generate enough income to support their families.
“We know where the fish are, but we don’t have the money to buy the kachki nets needed to catch them. The lake still has fish, but many of us cannot afford to adapt,” said Imam Hossain, president of the Rangamati chapter of the National Fishermen’s Association.
Haider, the BFRI scientist, said: “Without restoring breeding grounds, increasing carp fry stocking and regulating harmful fishing practices, carp populations in the lake are unlikely to recover.”
He cautioned that even with immediate action, recovery of the carp population would take time due to long-term changes in lake fishery.
Banner image: Fishing on the Kaptai Lake. Image by Alex Treadway/ICIMOD via Flickr (CC BY-NC-ND 4.0).
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Citations:
Lima, R. A., Ali, A., Rahman, M. K., Islam, M. S., Moniruzzaman, M. & Tamanna, T. A. (2023). An overview on hydro-biology and management of Kaptai Lake Fisheries, Bangladesh. International Journal of Aquaculture and Fishery Sciences, 9(3), 029-039. doi:10.17352/2455-8400.000089
Rahman, B. M., S., Rahman, M. K., Ali, A., Lima, R. A., Mia, M. L. & Mahmud, Y. (2024). Catch composition, catch per unit effort (CPUE) and species selectivity of fishing gears on multi-species Kaptai Lake in Bangladesh. Heliyon. 10(10). doi:S2405-8440(24)07204-9
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Cite this article
Sifayet Ullah (2026). Declining carp fishes in Bangladesh’s Kaptai Lake leave small-scale fishers struggling. Mongabay Conservation news. DOI: https://doi.org/10.66709/news-322452
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