Huong, D.T.T. and Lan, T.D., 2022. Ecosystem sustainability assessment using an economic valuation index for selected offshore islands in Vietnam. Journal of Coastal Research, 38(6), 1128–1134. Coconut Creek (Florida), ISSN 0749-0208.

Two sites around Bach Long Vi Island (North Vietnam) and Tho Chu islands (South Vietnam) were selected to perform an economic valuation index analysis for the sustainability assessment of insular coastal ecosystems. The critical study methods are based on indicators and index selection and analyses following the well-documented Driver-Pressure-State-Impact-Response framework. Total ecosystem economic indices were proposed and calculated using three subindices, including the direct use value index (Idev) of a factor of 35.71 for Bach Long Vi Island and 9.52 for Tho Chu islands, the indirect use value index (Iidev) of 39.38 and 9.52, and the nonuse value index (Inuv) of 100 for both study sites. A total economic valuation index (Ieev) of island coastal ecosystems, consisting of coral reefs and rocky reefs at both sites, was calculated using Idev, Iidev, and Inuv. Ieev values at assigned scale between 0 and 100 points; values lower than 50 indicate ecosystems used unsustainably. Within this 100-point scale, the Ieev for the coastal ecosystems surrounding Bach Long Vi Island from 2014-detected parameters was calculated as 58.37, revealing an overall sustainable use. On the contrary, the value for the Tho Chu islands for the same period was 39.68, indicating that this latter site was unsustainably used. Developing and analyzing these indices can be applied to other coastal ecosystems, such as beaches, mangroves, corals, etc., both in Vietnam and in similar international contexts.