Comparative assessment of Open-Sea and Integrated Mangrove Aquaculture Systems (IMAS) for Asian seabass (Lates calcarifer) culture: implications for growth performance, physicochemical characteristics and mangrove cover assessment

The present study compared the growth performance, feed utilization, water quality, primary productivity and sediment characteristics of Asian seabass (Lates calcarifer) cultured in an Open-Sea Cage culture system (OSC) and two Integrated Mangrove Aquaculture Systems (MP1 and MP2). Asian seabass were stocked at 10 fish m⁻³ in six HAPAs within each culture system and reared for 60 days. Growth, feed-utilization indices, water-quality parameters, primary productivity and sediment characteristics were monitored throughout the culture period. Body weight increased progressively in all systems, with significantly higher final weight in MP2 (27.01±0.34 g) than in MP1 (25.83±0.30 g) and OSC (23.22±0.11 g). MP2 recorded the highest weight gain, specific growth rate, feed conversion efficiency and protein efficiency ratio, while feed conversion ratio was lowest. Water-quality and productivity characteristics differed significantly among systems and sampling periods, with MP2 showing higher gross and net primary productivity and chlorophyll-a. Sediment characteristics also differed significantly with MP2 recording higher organic carbon, organic matter, total nitrogen and carbon stock. The findings highlight IMAS as a promising production-with-ecological-conservation approach enhancing aquaculture performance while retaining mangrove-based ecosystem functions, thereby supporting environmentally responsible seafood production and progress towards the SDGs.