Relationship between macrobenthic fauna community and environmental factors in Southeast Leizhou Peninsula of the South China Sea

Based on the data collected from 13 sampling stations in Southeast Leizhou Peninsula of the South China Sea in March 2014, we examined the characteristics of macrobenthic fauna community. Thirty-nine species of macrobenthic fauna were obtained. The highest number of species were mollusca, followed by Annelida. The dominant species of macrobenthic fauna were Mactra iridescens, Turritella bacillum, Timoclea scabra, Nassarius siguinjorensis, Moerella rutila and Notomastus aberans. The average biomass and abundance were 251.32 g · m^-2 and 480.0 ind · m^-2, respectively. The trend of spatial distribution was complicated, and the abundance was generally higher in southwest area but lower in northeast area. The results of cluster analysis and MDS show that macrobenthic fauna community could be divided into five significantly different groups (R=0.951, P=0.001) and there was great difference of dominant species among the groups. Overall, the diversity of macrobenthic fauna community for the survey area was higher. The Pielou evenness index, Margalef species richness index and Shannon-Wiener index were 0.59, 2.36 and 2.35, respectively; however, the diversity was low for each group. ABC analysis for five groups shows that macrobenthic fauna community in the surveyed area in spring was seriously disturbed, with poor community stability. The correlation analysis between macrobenthic fauna community and environmental factors show that hydrodynamic affects the content of heavy metals such as Cu, Cr in sediments and the disturbance is caused by human activity, which are the main factors affecting difference and instability of macrobenthic fauna community.