Biodiversity of mangrove mollusks in the west coast of Hainan Island, China.
We aimed to understand the mollusk community in the mangrove wetlands of the west coast of Hainan Island. To do so, we explored the temporal and spatial variation in species composition, diversity and community structure of mollusks in six mangrove wetlands from 2015 to 2016. We identified a total of 201 mollusk species belonging to 57 families. The dominant species included Cerithidea cingulata, Assiminea latericea, Pinguitellina cycladiformis, and Sermyla riqueti. The average density and biomass of mollusks were 324.13 ind./m2 and 142.88 g/m2, respectively. Observed density, biomass and species richness at west coast of Hainan Island were higher than values recorded in other mangrove wetlands located in the coast of Beibu Gulf. While species richness, density or biomass of mollusks did not vary seasonally, mollusk densities varied spatially in our study. Cluster analysis showed that mangrove wetlands differing in salinity, soil texture and mangrove communities had very dissimilar mollusk communities. The multivariate-AZTI marine biotic index (M-AMBI) value suggested that the mollusk communities of mangrove wetlands located in the west coast of Hainan Island were undisturbed. Although the benthic community was reasonably healthy, they were nevertheless negatively impacted by human activities and invasion of exotic plants. Given that mollusks are important for various bird species that migrate to Hainan Island, we recommend measures such as pollution control and in situ conservation to help preserve the biodiversity of mangrove mollusks in the west coast of Hainan Island.