Environmental variables involved in the development of bloom-forming cyanobacteria in a meso-to-eutrophic reservoir
Willame, Raphaël Thys; Jacquet, Véronique Verbanck; Cauchie, Henry-Michel Hoffmann
Plankton and environmental variables of a temperate meso-to-eutrophic reservoir have been monitored, from 1999 to 2001, in order to assess the factors controlling the development and the species assemblages of bloom-forming cyanobacteria.In term of relative abundance, cyanobacteria dominated the phytoplankton during several summer or autumnal days and led, each year, to surface scums in several parts of the reservoir. The dominant cyanobacteria belonged to the functional ecological groups H, S1 and L0 sensu Reynolds et al. (2002). Among the 19 recorded physical, chemical and biological variables, multivariate analyses displayed the role of silica, nitrate as well as water transparency on the yearly cyanobacterial development whereas ammonium, iron, water temperature and river discharge were the main variables having an effect on the cyanobacterial species composition.