Brood fish spawn in Halda River; egg collection continues

Carp brood fish, known locally as 'mother fish', have finally spawned in the Halda River — the only natural breeding ground for carp in South Asia — in the early hours today (30 May), bringing joy and smiles to egg collectors in Chattogram. 

The full spawning began around 2am across several points of the river, stretching from Madunaghat in Hathazari to Ramdas Munshir Ghat in Chattogram's Raozan.

This rare natural event occurred after favourable environmental conditions aligned following the new moon, with thunderstorms and moderate to heavy rainfall sweeping across the region, accompanied by hill runoff. These conditions are considered ideal for carp spawning in the Halda.

Fishermen, who had been waiting along the riverbanks since early April with nets and boats, quickly sprang into action to collect the fertilised eggs.

According to officials, the results of the collection varied by location. Some fishermen reported a good quantity of eggs, while others were disappointed with lower-than-expected yields. 

As a result, the total quantity of eggs collected this year has not yet been determined.

Professor Manzurul Kibria, coordinator of the Halda River Research Laboratory at the University of Chittagong, confirmed that eggs were collected from areas ranging from Ankurighona to Azimer Ghat during the tidal hours of the night. 

He added that the collection continued at various points along the river throughout the morning and into the afternoon. While some areas showed promising results, others did not. 

He emphasised that a few more days would be needed to assess the season's total yield.

The collected eggs will be placed in wells along the riverbanks, where they will hatch into larvae and eventually grow into fingerlings. These fingerlings are vital for aquaculture and support a large number of hatcheries across the country.

Earlier this season, there were two smaller spawning incidents involving four key carp species — Rohu, Mrigal, Catla, and Kalibaush. The eggs collected during those times were referred to as "sample eggs" by local fishers.

The Halda River, which spans about 98 kilometres across Chattogram's Hathazari and Raozan upazilas, is dotted with traditional breeding points. 

Around 350 boats carrying approximately 1,500 fishers had been stationed at various points, waiting patiently for the full spawning event.

Historically, the quantity of eggs collected from the Halda River has fluctuated due to environmental factors. 

In 2020, the river yielded a record 25,536 kgs of eggs. The collection was also notably high in 2018, with 22,680 kgs. 

In contrast, yields in 2021 and 2022 were comparatively lower, at 8,500 and 6,500 kgs, respectively. 

In 2023, the figure rose again to 14,664 kgs. However, last year, the collection dropped sharply, with only 1,680 kgs reported.

Researchers and fishery officials believe that climate variation, pollution, and other ecological factors may be contributing to the decline in egg production. The final figures for 2025 will become clearer in the coming days as data from different zones is compiled and analysed.