Preliminary study on macrobenthos community of a large riverine reservoir,Fuchunjiang reservoir in subtropical China

Four times of investigations were conducted on macrobenthos in Fuchunjiang reservoir in March,June,September and December of 2006.The results indicated that there were about 20 kinds of macrobenthos in Fuchunjiang reservoir,the average density was 375.10 ind/m2.Oligochaete was dominant in the density of the macrobenthos,however,molluscs was superior in biomass.Seasonally,the density and biomass of macrobenthos were higher in winter and early spring than in summer.In the spatial distribution,the highest density appeared in Xiaya site,and other sites were no significant difference.Oligochaete density was dominant in riverine zone but polychaeta density was dominant in lacustrine zone.The biomass of macrobenthos followed the order of lacustrine zonetransitional zone riverine zone.There was distinct relationship between sediment pellet and density of polychaetes.