Diversity of cyanobacteria and algae of urban gravel pit lakes in Bratislava, Slovakia: a survey

Abstract

This paper presents data on the diversity of cyanobacteria and algae of nine gravel pit lakes situated within the city boundaries of Bratislava, W Slovakia. During more than 30 years of investigations 187 genera and 591 infrageneric taxa were determined, of which 40 genera and 58 species belong to Cyanobacteria, and 147 genera, 492 species, 2 subspecies, 35 varieties and 4 forms belong to various groups of algae. From gravel and sand pit lakes in Slovakia several new taxa were established, e.g. Cyanocatena planctonica Hindak, 1975 and Planktocyanocapsa stagnalis Hindak, 2002 from the cyanobacteria, or Catenococcus tortuosus Hindak, 1977, Posonia sestonica Hindak, 1982 and Catenocystis gerulata Hindak, 1988 from the chlorophytes. Many taxa found were new records for this country. The floristic composition of the lakes investigated was rich but due to the uniformity of environmental conditions more or less similar. The majority of the taxa were diatoms, while the chlorophytes represented about 22%. As a whole, the taxonomic structure is typical of mesotrophic to eutrophic, slightly saline water of temperate zones, but some taxa may be considered characteristic of oligotrophic lakes.