Species biodiversity and distribution of seagrass beds in several coastal areas of central Vietnam

Abstract

Seagrasses provide habitat and abundant food supplies for numerous marine species and seagrass ecosystems play a vital role in protecting the coast from erosion. There were numerous seagrass studies in Vietnam, however, while these studies provide information on specific studied places, there is a lack of comparison between studies for providing a broad picture of the overall seagrass ecosystem along the coast of Central Vietnam. Hence, this study of species diversity and distribution of seagrasses along the coast of Central Vietnam was conducted to provide comparative data, which is highly valuable for the proper exploitation, management, and sustainable development of seagrass resources in Central Vietnam. This study identified eight species of seagrass belonging to two families—Hydrocharitaceae and Cymodoceaceae—in the waters around several islands in Central Vietnam. Among them Halophila beccarii in the Cua Dai estuary was listed in the Red List of Threatened Species by the International Union for Conservation of Nature (IUCN) (2017)—at risk of global extinction. The results revealed that the seagrass beds in several coastal areas of Central Vietnam have diminished over time with respect to the number of species and their distribution with causes attributed to anthropogenic activities. The seagrass canopy coverage ranged from 5 to 100% (57 ± 36.20%) near several coastal islands of Central Vietnam. The majority of seagrass is distributed in both intertidal and subtidal zones Our findings suggest that water quality and important sedimentary processes vital to ecosystem health need to be assessed throughout the coastal region.