Initial impact of low stocking density of grass carp on aquatic macrophytes

Grass carp (Ctenopharyngodon idella Val.) stocked at a low density (29 kg ha(-1)) to one of two small ponds significantly reduced the biomass of aquatic macrophytes (especially of the filamentous alga Cladophora globulina Kutz.) and changed the species composition of the higher aquatic plant community. After grass carp stocking (in 1999), A Myriophyllum spicatum L., Ceratophyllum demersum L. and Lemnaceae species replaced the species present originally: Eleocharis acicularis (L.) Roem. et Schult., Potamogeton pusillus L. and P. pectinatus L., which were dominant in 1998. (C) 2002 Elsevier Science B.V. All rights reserved.