Assessment of Tilapia Cage Culture and Disease Risk Factors in the Dakatia River, Bangladesh: Implications for Sustainable Aquaculture Development

Tilapia (Oreochromis niloticus) cage aquaculture has expanded rapidly across Bangladesh as a feasible source of rural livelihoods and to meet national fish demand. The Dakatia River, particularly in Chandpur Sadar Upazila, is a prominent site for small- and medium-scale cage farming. This study assesses the operational characteristics, profitability, and disease risk factors associated with tilapia cage culture in the river system. A total of 50 respondents from eight villages were surveyed using a structured interview to capture data on cage construction, stocking density, feed management, and disease incidence with symptoms. The results revealed that a locally made cage with a stocking of 500-600 fish per cage (20 ft × 10 ft × 10 ft) yields an average of 400 kg per cycle, with a net profit margin of Tk. 15830, highlight the economic feasibility of the practices.  However, the study also shows key vulnerabilities: 87.5% cage overcrowding within 5-10 m, poor pre-stocking hygiene, and an unknowingly excessive use of antibiotics. Seasonal disease outbreaks, especially during the monsoon, are associated with water turbidity, predator intrusion, and pathogen introduction from nearby sluice gates.  These findings underscore the urgent need for spatial planning, improved biosecurity, reduced reliance on antimicrobials, and farmer training in water quality monitoring and disease detection. Accounting for those findings can help fill the knowledge gap on open-water cage farming in Bangladesh and offer policy-relevant insights to enhance health-resilient, sustainable aquaculture systems in the country. Res. Agric. Livest. Fish. Vol. 13, No. 1, April 2026: 183-196