Abstract:
Based on the survey of macrozoobenthos in the adjacent areas of Dalian Island seaweed beds in the North Yellow Sea during May (spring) and August (summer) 2020, this paper analysed the community structure of macrozoobenthos during the seasons of macroalgae growing and decaying and its relationship with environmental factors including total polyphenol content, which is an indicator of macroalgal detritus in surface sediments. The results showed a total of 134 macrozoobenthos species were collected, with fewer species recorded in spring (94) than in summer (111). Total average biomass was greater in spring (179.75 g/m
2) than in summer (141.84 g/m
2), but the reverse was true for total average abundance, i.e. 573.67 and 647.50 ind./m
2 in spring and summer, respectively. Based on CLUSTER analysis, the macrozoobenthos community could be divided into three groups in spring and two groups in summer. A significant difference in community composition was found between the two seasons (ANOSIM: Global
R=0.031,
P<0.05), which was mainly driven by
Ophiopholis mirabilis,
Grandifoxus aciculata and
Nebalia sp.. Canonical Correlation Analysis (CCA) indicated, water depth (
F=13.9,
P=0.002), median sediment particle size (
F=3.8,
P=0.002) and bottom water temperature (
F=3.1,
P=0.006) were found to be the main driving factors influencing the macrozoobenthos community. In addition, differences were observed in the effects total polyphenol content had on individual species. A significant positive correlation was detected between total polyphenol content and the abundance of
Lumbrineris latreilli,
Amphioplus japonicus,
Cirriformia tentaculata and
Ophiopholis mirabilis (all
P<0.05). However, a significant negative correlation was found between total polyphenol content and the abundance of
Platynereis bicanaliculata,
Moerella jedoensis and
Nitidotellina sp. (
P<0.05).