长肢秀体溞对富营养化水体藻类的生物操纵

在实验室和开放生态系统中研究了长肢秀体溞(D iaphanosoma leuchtenbergianumF ischer)对斜生栅藻(Scem edesmus obliquusTurp)、铜绿微囊藻(M icrocystis aeruginosa)和蛋白核小球藻(Chlorella pyrenoidosaCh ick)的牧食力和对水体中浮游动物和藻类数量、生物量、群落结构及水体中理化性质的影响,结果表明:藻类生物量在一定范围内,长肢秀体溞的摄食速度随藻类生物量增加而增加,藻类生物量超过一定值(即饱和值)时,摄食速度随之下降。长肢秀体溞对斜生栅藻和小球藻具有较高的选择性,对铜绿微囊藻的选择性较差。水泥池中每升水放养长肢秀体溞600个以上,即可对水体中浮游动物和藻类的数量、生物量、群落结构产生显著的影响,同时降低水体中总氮、总磷和CODMn的浓度,增加水体透明。7月份之前,可以利用放养长肢秀体溞的方法来控制水体中藻类。

Biomanipulation of Algae in Eutrophicated Waters by Diaphanosoma leuchtenbergianum Fischer

The grazing rate of Diaphanosoma leuchtenbergianum Fischer on Scemedesmus obliquus Turp,Microcystis aeruginosa and Chlorella pyrenoidosa Chick,and effects of the Diaphanosoma on the amount,biomass and community formation of zooplankton and algae in waters,and on physiochemical properties of waters were studied.The results showed that Diaphanosoma leuchtenbergianum grazing rate increased with the growth of algae biomass within a definite range of algae biomass,but the grazing rate dropped when the biomass exceeded the saturation quantity.The selective coefficient of Scemedesmus obliquus Turp and Chlorella pyrenoidosa Chick for Diaphanosoma was bigger than that of Microcystis aeruginosa.When the quantity of Diaphanosoma leuchtenbergianum exceeded 600 in a liter of water in the pond,the Diaphanosoma could affect obviously the amount,biomass and community formation of zooplankton and algae in the waters,decrease the concentrations of total nitrogen,total phosphorus and COD_(Mn)of the waters,and increase diaphaneity of the waters.Algae bloom could be controlled by the release of Diaphanosoma leuchtenbergianum Fischer in waters before July.