The Ecological Study On The Macrobenthos In The Northwest Waters Of Jiaozhou Bay

Based on the data collected during5cruises from8sampling stations in the northwest waters of Jiaozhou Bay during Nov.2010to Dec.2011, the macrobenthic species composition, dominant species, abundance, biomass, biodiversity, and community structure are analyzed. The ecological environment quality of the survey area is evaluated by using diversity index, ABC curves and AMBI. The effect of Ruditapes philippinarum farming on macrobenthos community structure is studied by comparing the macrobenthos structure in the farming area and in the non-farming area.A total of182macrobenthic species are identified in the survey area, of which83species are Polychaeta,21are Mollusca,62are Crustacea,7are Echinodermata, and the rest9species are other taxonomical groups (belonging to Coelenterata, Nemertinea,Oligochaeta, Brachiopoda and Chordata).The total average abundance in the survey area is5010.2ind./m2(not including the abundance of R. Philippinarum), of which the abundance of Polychaeta is4434.7ind./m2, Mollusca is121ind./m2, Crustacea is370.3ind./m2, Echinodermata is56.2ind./m2and other taxonomical groups is28ind./m2The total average biomass in the survey area is46.58g/m2(not including the biomass of R. Philippinarum), of which the biomass of Polychaeta is7.568g/m2, Mollusca is7.532g/m2, Crustacea is4.132g/m2, Echinodermata is21.701g/m2and other taxonomical groups is5.647g/m2.The mean abundance and biomass of R. Philippinarum are respectively282.5ind./m2and155.913g/m2.The dominant species in the survey area are Sternaspis scutata, Tharyx multifilis, Nephtys oligobranchia, Scoloplos sp., Scoloplos sp., Ophiodromus anguotifrons, Prionospio sp., Mediomastus sp., Cossurella aciculata, R. Philippinarum and Protankyra bidentata.The AMBI can sensitively reflect the changes of macrobenthos community effected by the interference. The ecological environment quality of the survey area is evaluated to be good by using diversity index, ABC and AMBI. The diversity index of macrobenthos community in the R. Philippinarum farming area is lower, and there are more opportunistic species in the macrobenthos community.The abundance of macrobenthos in this study is higher than other results of studies in the Jiaozhou bay. The abundance of macrobenthos in the Jiaozhou bay was underestimated perhaps, because some dominant species in this study (e.g. Prionospio sp. and C. aciculata) weren’t mentioned in other results.