Authors: van Donk E Gulati R D
Publish Date: 1995/08/01
Volume: 32, Issue: 4, Pages: 197-206
Abstract
Six years after application of biomanipulation in 1987 Lake Zwemlust The Netherlands returned during the summer from a clear water state dominated by aquatic vegetation to a turbid state characterized by high algal biomass Herbivory and growth of epiphytes on macrophytes were the main factors triggering the switch Selective herbivory by coots Fulica atra and rudd Scardinius erythrophthalmus caused a change in macrophyte species composition from a dominance of Elodea nuttallii in 1988/1989 to Ceratophyllum demersum in 1990/1991 and finally to Potamogeton berchtholdii in 1992/1993/1994 Observations revealed a general lack of epiphytes associated with Elodea and Ceratophyllum while Potamogeton showed a progressive coverage with epiphytes causing Potamogeton to decline markedly during late summer Phytoplankton blooms dominated by cyanobacteria appeared again during three consecutive autumns 1992 1993 and 1994 with chlorophyllα concentrations reaching 60240 μg 1−1
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