The Ecological Study On Macrobenthos In The Southern Yellow Sea,china

According to the investigations in Southern Yellow Sea from2011（June andNovember）to2012（May and November, the macrobenthic species composition,dominant species, abundance, biomass, biodiversity, and community structure areanalyzed. The ecological environment quality of the survey area is evaluated by usingdiversity index, ABC curves. By comparison with historical data，the change of macrobenthos inthe Southern Yellow Sea is analyzed.1.A total of343macrobenthic species are identified in the survey area, of which165species are Polychaeta,42are Mollusca,98are Crustacea,15are Echinodermata,and the rest23species are other taxonomical groups (belonging to Coelenterata,Nemertinea,Oligochaeta, Brachiopoda，Chordata and so on).2.The total average abundance in the survey area is903.8ind./m2, of which theabundance of Polychaeta is606.2ind./m2, Mollusca is76.9ind./m2, Crustacea is158.5ind./m2, Echinodermata is22.3ind./m2and other taxonomical groups is39.8ind./m2.3.The total average biomass in the survey area is15.9283g/m2, of which thebiomass of Polychaeta is5.1023g/m2, Mollusca is1.8347g/m2, Crustacea is1.3337g/m2, Echinodermata is4.3188g/m2and other taxonomical groups is3.3388g/m2.4.The main sedimental type is silt，as the same time that sand and clay are alsofound in special stations.5.The dominant species in survey area are:Thyasira(Thyasira) tokunagai,Eudorella pacifica, Notomastus latericeus）, Capitella capitata）and Mediomastussp..But we also found a little differences in different cruise.6.The Shannon-Wiener diversity index shows that environment is clean,but inspecial stations are moderately polluted. 7.The AMBI value are between1.304~3.125，which show that survey areaenvironmental are fine.8.Based on abundance of macrobenthos we can identify community by clusteranalysis.The distribution of communities are estuary, nearshore, away from the coaston the whole.9.By comparison with historical data,we find the difference in abundance andbiomass.The total average species and abundance is more than previous results,but thetotal biomass is lower than precious results.10.Compared with the historical data of adjacent waters,the total species weresimilar in the Bohai Sea,the North Yellow Sea,the South Yellow Sea.