Abstract
A ten-year period of monitoring of the Rímov reservoir was chosen to demonstrate the impact of fishstock manipulation on phytoplankton biomass and on species composition of the pbytoplankton assemblage. Biomass of planktivorous fish decreased substantially under various forms of biomanipulative pressure. The proportion of large individuals of Daphnia galeata (retained on the 0.71 mm mesh sieve) increased from nearly 0 to 9% of the total zooplankton biomass during the period of 1985–1988 and remained nearly constant during subsequent years. Change in zooplankton structure had no significant response in the abundance of phytoplankton. Species composition of phytoplankton assemblage, however, changed considerably after the large daphnids had reached a biomass of more than 10 mg.m-2 of protein-N. Aphanizomenon flos-aquae var. flos-aquae formed about 8% of phytoplankton biomass before 1985, while its share increased to 40–65% during 1988–1990. Later, Aphanizomenon was replaced by other large forms of algae. The factors possibly influencing Aphanizomenon blooms are discussed with respect to the situation in other water bodies.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
