Abstract:
The aim of this study is to explore the current structure of macrobenthos communities in the northern Beibu Gulf, evaluate the benthic ecological quality status of the northern Beibu Gulf, and provide scientific insights for the ecological conservation and management of the Beibu Gulf. In this study, the macrobenthos was sampled at 12 sites in the northern Beibu Gulf, in the autumn (November) of 2022. The species composition, abundance, biomass, and diversity indices of macrobenthos were analyzed. To assess ecological quality comprehensively and reveal the disturbance in the northern Beibu Gulf, three methods were used, including AZTI’s marine biotic index (
AMBI) and multivariate
AMBI (
M-AMBI) index, as well as the abundance-biomass comparison (ABC) curve analysis. A total of 30 species of macrobenthos were identified in the northern Beibu Gulf, primarily composed of annelids with 12 species, followed by mollusks (8 species) and arthropods (6 species), and fewer echinoderms and other species. The average abundance and biomass of macrobenthos were 148 ind./m
2 and 135.04 g/m
2, respectively. The abundance of macrobenthos was dominated by polychaetes and mollusks, while the biomass was overwhelmingly dominated by mollusks. Overall, both the abundance and biomass in the inshore areas were greater than those in the offshore areas.The dominant species were
Timoclea scabra, Paraprionospio pinnata, and
Aglaophamus dibranchis. The results of Cluster analysis and non-metric multidimensional scaling (nMDS) indicated that the macrobenthos communities could be divided into three sub-communities. The result of ABC curve analysis indicated that the macrobenthic community has not been disturbed. The results of the
AMBI and
M-AMBI indicated that almost all sites, except for one moderately disturbed site, have been slightly disturbed or undisturbed, suggesting that the benthic habitat quality status is good or high. In summary, the preliminary results of this study indicate the macrobenthos communities in the northern Beibu Gulf received relatively lower disturbances, and the overall ecological quality status in this area was good.