Economic Viability and Scalability of Tube Net Seaweed Farming for Kappaphycus alvarezii in Coastal Communities of India

This study explores the economic viability and adoption of the tube net method for seaweed farming, particularly for Kappaphycus alvarezii cultivation, along the southeastern coast of Tamil Nadu, India. The research examines the financial feasibility, operational costs, and socio-economic characteristics of coastal farmers engaged in seaweed cultivation using this method. Primary data was collected from 120 farmers in Mandapam taluk, focusing on investment, operational expenses, yields, and labor requirements. The results show that the method offers a promising alternative to traditional bamboo raft farming, with substantial profitability potential. The system yields an estimated 39,000 kg of fresh seaweed per year, generating a gross sales income of ₹3,90,000 annually, with net earnings of ₹1,56,755 per year for a 25-raft unit. The benefit-cost ratio of 1.67 indicates a high return on investment, and the system’s low break-even price of ₹59.81 per kilogram demonstrates its financial resilience. The modular design allows for scalability, making it accessible to small-scale farmers with minimal financial barriers. The study concludes that despite its advantages, the tube net method faces some challenges like limited awareness, high initial costs, and regional ecological constraints affect adoption. The method remains sustainable, profitable, and community-friendly, aligning with government livelihood schemes and blue economy goals.