Evaluation of Ecosystem Services Provided by Pacific Oyster, Crassostrea gigas, Farms in Hansan Bay, Korea

Korea is the second highest producer of cultured Pacific oyster, Crassostrea gigas, in the world, but their potential economic values of ecosystem services have not yet been evaluated. As the first case study, we evaluated the potential values of C. gigas cultured in Hansan Bay, Korea. We utilized Gangnery's growth model to assess the provisioning and regulating services, assuming that the nitrogen removal amount equals the difference between input and harvested oysters in terms of accumulated nitrogen. To convert these measured services into monetary values, we used the market price of C. gigas for provisioning service, and the annual operational report regarding the current state of domestic sewage treatments for regulating service. We estimated that cultivating a ha of C. gigas farms has a monetary value ranging from ca. -16.6 to 67.6 thousand US dollars, which is considerably lower than other research findings. Results suggested that the growth model applied in this study is suitable and effective, particularly in cases where other models may not be applicable. Additionally, we compared the values of coastal areas when shifting from C. gigas cultivation to another species or maintaining the status quo to assist policymakers in making decisions. Despite some limitations, our model is expected to contribute to appraising the monetary values of coastal areas and mitigating conflicts in marine spatial planning.