Ecological Studies on the Macrobenthos Community in the Intertidal Zones of Bohai Sea in Autumn

Based on analysis of sediment samples and 30 biological samples collected from 11 intertidal zones in September 2008 around Bohai Sea,as well as temperature,pH and ρ(DO) measured on-site,the characteristics of the macrobenthic community and their relationship to environmental factors were studied.Seventy-six macrobenthic species were identified in the research region,including 25 species of polychaeta,24 of mollusca,19 of crustacean and 8 in other phyla.The density of the macrobenthos in this area was(367.40±187.30) m-2,and their biomass was(100.90±56.40) g/m2.Data analysis showed that there was no obvious dominant species in this community,and only four species had a dominant value over 0.01: Umbonium thomasi(Crosse,1863),Mactra veneriformis(Reeve,1854),Callianassa harmandi(Bouvier,1901) and Hemigrapsus sinensis(Rathbun,1929).The Shannon-Wiener index in Laizhou,which is in the mouth of the Bohai Sea,was 1.909,which was the highest in all the sample areas.The similarity of the macrobenthic community structures in the 11 sample areas was low,with a similarity of about 20%.CCA analysis showed that the species number,density and biomass of macrobenthos in the study area were significantly related to substrate types,but not to temperature,pH or ρ(DO).Compared with historical records of these regions,the species number of macrobenthos in the intertidal zones around Bohai Sea declined sharply over the past 30 years due to various factors including the change of the area's survival environment,pollution and more.