생태통합양식(IMTA)의 환경·경제적 가치 분석

Abstract

Integrated multi-trophic aquaculture (IMTA) is one approach to mitigate some of the negative environmental impacts associated with excess inorganic and organic nutrients of finfish aquaculture and has been steadily gaining momentum worldwide. This study aimed to evaluate environmental benefits as well as economic effectiveness of multi-trophic aquaculture (IMTA) compared to the monoculture system. Based on the biological and economic data collected from a pilot IMTA project for Korean rockfish(Sebastes schlegelii), Pacific oyster(Crassostrea gigas), and sea cucumber(Stichopus japonicus) in Yangyang-gun, Gangwon-do, South Korea, farming revenue and expenses during the farming period were evaluated. In addition, as index of economic evaluation, the net present value (NPV) and internal rate of return (IRR) of 10-year cash flow and cash outflow were estimated. The results of the economic analysis indicated that the IMTA system would have higher economic outcomes than those of the monoculture system. In particular, NPV and IRR of IMTA system were estimated to be higher than those of the monoculture system with the discount rate of 4.5%. The results of sensitivity analysis on survival rates and market prices as main biological and economic variables indicated that the economic viability of IMTA system would be less vulnerable to production and market condition changes in comparison with monoculture system. Finally, the environmental benefits of IMTA system were evaluated to be about 8.5 million∼93.2 million KRW.