THE DISTRIBUTION OF JUVENILE FISHES IN A HYPEREUTROPHIC POND - CAN MACROPHYTES POTENTIALLY OFFER A REFUGE FOR ZOOPLANKTON

The distributions of juvenile cyprinids (roach Rutilus rutilus, rudd S cardinius erythrophthalmus, and their hybrids) and perch (Perca fluvia tilis) were investigated in Priest Pot, a hypereutrophic pond in the E nglish Lake District, in relation to macrophytes (Nuphar lutea), water temperature, and dissolved oxygen. Juvenile (0+, 1+ and 2+) cyprinids and perch were found both among dense, peripheral macrophytes and in the open water of the pond, although the cyprinids were apparently mor e abundant amongst the macrophytes. The implications of these findings for the viability of macrophytes as refuges for zooplankton are discu ssed in the context of biomanipulation.