Analysis on the Characteristics of Macrobenthos Community during Autumn in the Yangma Island

Based on the data collected in the Yangma Island,Yan Tai in September 2010,the characteristics of macrobenthos community were studied.The results showed that polychaetes were numerical dominant in the area.The macrobenthos community could be divided into four groups,the abundance of Lumbrinereis longiforlia,Sigambra sp.and Mediomastus sp.Were the main differences in different groups.Such difference was mainly caused by the difference in habitat conditions.The range of Shannon-Wiener index of macrobenthos in the investigated area was 1.17 ～ 2.92,with an average of 2.13.Human disturbances were the main reasons for the differences in diversity between groups.The whole community structure of groups,which distributed in the main navigation route and mariculture area,were less stable,suggesting the sediment environment of investigated area may have been subjected to various degrees of deterioration.