Macrobenthos diversity in intertidal zone of Dazhuyu Island,Dongtou County of Zhejiang Province

Investigations were made on the macrobenthos diversity in intertidal zone of Dazhuyu Island in April 2009(spring),July 2009(summer),October 2009(autumn),and January 2010(winter).A total of 125 macrobenthos species were collected,including 57 mollusca,24 crustacea,6 coelenterates,6 other animals,and 32 macroalgae,accounting for 45.6%,19.2%,4.8%,4.8%,and 25.6% of the total,respectively.The dominant species in high,mid,and low tidal zones were Nodilittorina exigua and Littorina brevicula,Tetraclita japonica and Septifer virgatus,and Hydroides sp.,Sargassum thunbergii,and Lithophaga curta,respectively.The macrobenthos abundance was averagely 1637 ind·m-2,and the biomass was 2851.63g·m-2 on average.The Shannon index,Margalef index,and Pielou evenness index were 1.63,3.36,and 0.35,respectively.There was a consistency between the results of hierarchical clustering and non-metric multidimensional scaling analysis.The abundance/biomass curve showed that the community structure of macrobenthos in the intertidal zone of Dazhuyu Island had been disturbed,but the community was relatively steady.