This research investigates the economic and environmental sustainability of seaweed farming and Cobia agriculture in Ramanathapuram District, Tamil Nadu. Farmers utilizing bamboo rafts for seaweed cultivation gather 200–260 kg every 45 days, generating annual revenues ranging from INR 50,000 to 100,000 per raft per year. Nonetheless, obstacles such as inadequate bamboo raft design, resulting in fish consuming seaweed, and temperature variations that diminish yields, impede optimal potential. Cobia aquaculture faces challenges, including inadequate cage design and elevated feed expenses resulting from the species’ carnivorous appetite. Insufficient cage designs result in a 100% escape rate of hatchlings, causing financial losses. This emphasizes the necessity of enhancing fish cage designs and investigating economical feed substitutes such as Azolla to diminish reliance on small fish. Not withstanding these limitations, the integration of seaweed farming with cobia growing illustrates the potential to improve community lives, foster sustainable aquaculture, and save coastal habitats adjacent to UNESCO-protected areas.