Comparative Analysis of the Economic Feasibility of Using Extruded Pellets and Raw Fish-Based Moist Pellets as Aquafeed in Olive Flounder (Paralichthys olivaceus) Aquaculture in South Korea

South Korea’s olive flounder aquaculture industry predominantly relies on raw fish-based moist pellets (MP), raising concerns regarding marine resource use and environmental sustainability. This study compared the growth performance and economic feasibility of extruded pellets (EP) and MP through a 12-month feeding trial conducted at two commercial olive flounder farms in Wando, South Korea. At each farm, three replicate tanks were assigned to each dietary treatment. Economic feasibility was assessed using net present value (NPV), internal rate of return (IRR), and sensitivity analyses of key production and cost variables. Final body weight and survival rate were significantly higher in the MP groups than in the EP groups at both farms. In the baseline analysis without government subsidies, Farm A recorded an NPV of USD 793,446 and an IRR of 14.1% for EP, compared with USD 2,244,588 and 28.8% for MP. At Farm B, the corresponding values were USD 705,580 and 13.1% for EP, compared with USD 2,836,482 and 34.3% for MP. Although both feeding systems were economically feasible, MP demonstrated greater economic returns, primarily due to higher growth performance and lower feed costs. These findings highlight the need to improve EP performance and cost-effectiveness while considering the long-term sustainability of aquaculture feeding strategies.