Dhaka, Feb. 16 -- Bangladesh's hilsa catch is shrinking at an alarming pace as rising temperatures, erratic rainfall and shifting river flows disrupt breeding cycles, threatening supplies of the country's national fish and a key source of income for thousands of fishermen.

Researchers warn that without urgent climate adaptation and river management measures, the decline could deepen, posing long-term risks to food security and rural livelihoods.

Even during the peak season, rivers across the country are yielding far fewer hilsa, a geographical indication (GI) product and Bangladesh's national fish, compared to previous years, fishermen say.

In Chandpur's Haimchar upazila, widely known as the hilsa capital, veteran fisherman Asad Hossai...