The population dynamics of Keratella cochlearis in a hypereutrophic tarn and the possible impact of predation by young roach

Priest Pot is a shallow hypereutrophic tarn that supports large numbers of rotifers and young roach (Rutilus rutilus (L).). In this paper we describe the planktonic rotifer community of the tarn and show that the young roach feed extensively on Keratella cochlearis. A two year study of the population dynamics of K. cochlearis, nevertheless, failed to detect any obvious demographic effects of roach predation. Some general comparisons of fish biomass and rotifer production suggest that the fish are unlikely to influence the development of their rotifer prey in such a productive system.