| Abstract [eng] |
Toxic cyanobacteria blooms in freshwaters cause a complex water quality issue. Therefore, it is crucial to assess the emerging challenges of global warming and anthropogenic eutrophication that intensify blooms, shift the composition of potentially toxic cyanobacteria and profile of cyanotoxins. In the current study, cyanobacteria biomass, potential producers of cyanotoxins, and environmental variables responsible for their development as well as the profile of intracellular cyanotoxins were assessed in two shallow temperate eutrophic Lakes Širvys and Jieznas. Producers of microcystins and saxitoxin were confirmed based on molecular and/or chemical analysis of the strains. Saxitoxin, anatoxin-a, cylindrospermopsin, bioactive non-ribosomal peptides and one of alien species were detected for the first time in Lithuanian freshwaters. Also, the strains of dominant native bloom-forming Planktothrix agardhii, Aphanizomenon gracile and alien Sphaerospermopsis aphanizomenoides, Chrysosporum bergii cyanobacteria species were experimentally tested. The significance of temperature and nutrient availability on the growth of native and alien cyanobacteria, the content of cyanotoxins and interspecies competition was determined. |
