Cost–benefit analysis of mangrove restoration in Thi Nai Lagoon, Quy Nhon City, Vietnam
With over 10 million hectares of mangrove spread across the coastline of Vietnam, mangroves are considered an important resource for socio-economic development as well as playing a role in both the mitigation of, and adaptation to, climate change. Located in Binh Dinh province, Thi Nai is the largest lagoon with mangroves on the south central coast of Vietnam. However, in the last decade, the extensive loss of mangroves has taken place due to the expansion of urbanisation, aquaculture development and infrastructure construction. This paper presents the findings of a cost–benefit analysis of mangrove forest restoration and its alternative of aquaculture development in 150ha of wetland in Thi Nai Lagoon by using ‘willingness to pay’ estimates and market-based pricing methods to analyse 271 questionnaires completed during a household survey. This study reveals that mangrove forests provide important tangible and intangible benefits to local communities. In addition, in the context of climate change, mangroves also provide socio-economic development opportunities, particularly for fishing communities, such as fishing, eco-aquaculture, ecotourism, fuelwood collection, biodiversity conservation, carbon sequestration and shoreline stabilisation. Mangrove forest restoration also generates larger benefits than that of aquaculture: about VN$21 billion compared to VN$10 billion over 22 years. The benefits of mangrove restoration are approximately double that of aquaculture development, from a 5 per cent per cent to a 15 per cent per cent discount rate. In the context of climate change, with an increase in the frequency and intensity of climate change-induced hazards and sea-level rise, mangrove forest restoration generates even more benefits for communities. It is strongly recommended that policymakers should consider conducting a cost–benefit analysis of mangrove restoration and its alternative options to decide the best use of wetlands and to promote sustainable development.