Recent use of habitat service value for tourism and impacts on coral reefs in the target destinations in Southern Vietnam

Among these destinations, Nha Trang bay has a longer history of marine tourism, starting with inshore development and expanding to islands in and around the bay. In contrast, tourist activities in Cu Lao Cham islands and Ninh Thuan were developed in conjunction with the establishment and management of Marine Protected Areas (MPAs). Phu Quoc, on the other hand, has become a new destination and has attracted significant investments for the extensive development of tourism in the islands. The economic value generated from the use of coral reefs for tourism has increased significantly. For instance, the payment of entry fees to Cu Lao Cham MPA has increased year by year, reaching approximately 700,000 USD in 2018, while in Ninh Thuan, the payment reached around 50,000 USD in 2017 and up to 200,000 USD in 2018. However, reclamation for infrastructure development on inshore land and islands has been considered a serious impact, resulting in the loss of terrestrial and underwater habitats, such as the loss of Melaleuca forest in Phu Quoc islands or seagrass beds and coral reefs in Nha Trang bay, and increased sediment loading to coral reefs. Overexploitation of living resources for high food and souvenir demands has occurred in all areas, leading to the modification of communities, poverty, and uncertainty for resource recruitment. Among these areas, Phu Quoc waters are the most vulnerable to coral bleaching due to increased surface temperature, with records of mass bleaching in 2010 and 2016. Although MPAs exist in all study areas, the role of conservationists in developing coral reef tourism has been significant only in Cu Lao Cham case but poor in others. Local managers and businesses should pay more attention to sustainability to ensure not only coral reef conservation but also long-term benefits for local communities and the tourist sector itself. The service value of coral reefs for tourism can be categorized into direct and indirect values. Direct values include the use of coral reefs for tourism and recreation, while indirect values include the ecosystem services provided by coral reefs, such as water filtration, shoreline stabilization, and carbon sequestration. The economic value of coral reefs can be estimated using various methods, including the travel cost method, the contingent valuation method, and the hedonic pricing method. The study of coral reefs has been a topic of interest for many researchers. A number of studies have investigated the economic value of coral reefs, including the study by Trinidad [1], which estimated the economic value of coral reefs in the Philippines. The study found that the economic value of coral reefs was significant, with a total value of approximately 14 billion pesos over a period of 14 years. However, the study also found that the economic value of coral reefs was threatened by various human activities, including overfishing, coastal development, and climate change. The coral reefs in Southern Vietnam are a unique and valuable ecosystem that provides a range of ecosystem services, including water filtration, shoreline stabilization, and carbon sequestration. The coral reefs in the region are divided into 17 key areas, with a total area of 13,355 ha, and are considered one of the most biodiverse ecosystems in the region [3]. The coral reefs in the region are home to a wide range of species, including fish, invertebrates, and algae, and play an important role in supporting the livelihoods of local communities [4].