Features of the soft-bottom subtidal macrobenthos in Nha Trang Bay (Vietnam, South China Sea)

General characteristics of macrobenthos of the muddy sediments of the subtidal (19–24 m) zone in Nha Trang Bay (South Vietnam) were described based on the survey performed in April–May 2002. The mean abundance of organisms was 637 ind/m² and the mean biomass was 2.3 g/m². Sixty-seven macrobenthic species were found during the study. The main structural features of the macrobenthos were high species diversity, low species recurrence, and high eveness of the species structure with the absence of clearly manifested dominants. The number of species encountered regularly increased with the increase in the total area sampled from 210 to 5000 cm², though the relation did not reach saturation. The similarities and differences between the macrobenthos structures in Nha Trang Bay and those in some tropical and boreal soft-bottom communities are discussed.