Analysis on the characteristics of macrobenthic animal communities inside and outside the autumn marine ranch on Yantai Changdao Island
To clarify the composition and distribution characteristics of macrobenthic communities in Yantai Changdao Island marine ranch and evaluate the impact of marine ranching on these macrobenthos,sampling sta-tions were set up inside and outside the marine ranch in October 2022.Surveys of macrobenthic animals and the characteristics of macrobenthic communities were analyzed.A total of 88 species of macrobenthic animals were collected and identified during this voyage.Although the number of species in the pasture and control area was sim-ilar,the dominant groups differed.In the pasture,70 species were identified,with mollusks being the dominant group;whereas,in the control area,69 species were identified,with annelids as the dominant group.Eight domin-ant species were found,including 3 mollusk species in the pasture and 6 species in the control area,comprising 2 mollusk species,1 echinoderm species,and 3 annelid species.The average abundance and biomass of mac-robenthic animals in the pasture were significantly higher than those in the control area.However,Margalef spe-cies richness index(d),Pielou evenness index(J'),and Shannon Wiener diversity index(H')values showed little difference between the pasture and the outside.The results of Cluster analysis(CLUSTER)and non-metric multidi-mensional scaling(NMDS)analysis indicated that relatively low similarity among each station inside and outside the marine ranch.The AMBI and m-AMBI analyses revealed that the overall pollution disturbance in the studied water area was relatively small,indicating good benthic ecological health.Combined with historical data,the ana-lysis revealed a significant increase in species abundance and biomass of macrobenthic communities in the sur-veyed area.These results suggest that the development of marine pastures has a certain degree of impact on the growth and development of macrobenthic communities.