Seasonal development of Planktothrix agardhii Anagnostidis et Komarek and Limnothrix redekei (Van Goor) Meffert in a sharply stratified hypertrophic lake
Kangro, Kersti; Nõges, Peeter
published: Aug 1, 2003
ArtNo. ESP142014800005, Price: 29.00 €
Thermal and chemical regime and phytoplankton development in hypertrophic sharply stratified L. Verevi (S-E Estonia) were studied from April to October 2000. The lake stratified shortly after the ice break-up in April. Even in the homothermal conditions in October the lake remained chemically and biologically stratified. Limnothrix redekei being a minor component of the cyanobacterial community, reached its maximum (1.4 g.m−3) in the metalimnion in May. The biomass peak of the dominating Plankothrix agardhii followed in July (37.6 g.m−3). The biomass maximum of L. redekei was reached in cooler water at lower nitrogen and phosphorus concentrations compared with P. agardhii. Light conditions and the total N: total P ratio in the layer of the biomass peaks were similar. Nitrogen limitation was suggested as the main reason for the observed seasonal succession of the two cyanobacterial species.