Juvenile yield and adult abundance, genetic diversity and structure, and linkages among marine habitats for goldlined spinefoot (Siganus guttatus) in the coastal waters of Vietnam

Abstract

Assessments of the status and ecological linkages of target fish species related to marine habitats are playing important roles in enhancing the effectiveness of marine protected areas (MPAs) and of management in other coastal areas. In this study, we assessed juvenile yield and the abundance of goldlined spinefoot (Siganus guttatus) by using local knowledge and visual census in coastal waters of Vietnam. Genetic structure was examined by using DNA analysis of juve-niles, collected in seagrass beds and mangroves at major lagoons and estu-aries, and of adults, collected from coral reefs. More than 38.6 million juveniles were collected from 8 coastal lagoons and estuaries. The coastal lagoons and estuaries with seagrass beds supported high yield of juveniles, and the nearby MPAs had higher densities of adults. Three distinct genetic groups were identified, with one group found off the central part of the eastern coast from Con Co Island to Quy Nhon Bay, a sec-ond group found off the southeastern coast from Nha Trang Bay to the Con Dao Islands, which are located off the southern tip of Vietnam, and a third group found off the southwestern coast at the Phu Quoc Islands in the Gulf of Thailand.