Abstract:

Sizefractionated chlorophylla of phytoplankton and water quality variables were investigated monthly from June 2005 to May 2006 in Dianshan Lake.Results showed that the chlorophylla concentration of microphytoplankton (20～200 um) and nanophytoplankton (2～20 um) were main contributors to the annual mean of chlorophylla in Dianshan Lake,both accounting for 7479%.Seasonal variations of percentages of all sizefractionated chlorophylla were closely related with seasonal succession of phytoplankton community structure.Percentage of microphytoplankton chlorophylla peaked in spring,while that of nano,picophytoplankton peaked in autumn and winter,respectively.Bivariate correlation analysis showed that percentage of microphytoplankton chlorophylla was correlated positively with NH3N,while that of nanophytoplankton〖JP〗 was correlated negatively with NH3N.〖JP2〗Percentage of picophytoplankton chlorophylla was correlated negatively with BOD5,significantly.Correspondingly,the feasibility of nonclassic biomanipulation in controlling algal bloom in Dianshan Lake on the basis of feeding habits of aquatic animals such as filtering fish was also discussed