Algal occurrence, with particular emphasis on diatoms, was investigated over a two-year period on the travertine barriers of the Krka River in Slovenia. The purpose of the investigation was to establish qualitative composition and the relative abundance of the periphyton. In 1999 and 2000, basic physical and chemical parameters were measured. Altogether, 81 algal taxa were determined. Most of them belonged to Bacillariophyceae. Fifteen species and subspecies were new to Slovenia, 14 of them belonging to Bacillariophyceae and one to Cyanobacteria. Most of the new species and subspecies belonged to genera Nitzschia (5) and Navicula (4).Tijekom dvije godine istraživana je prisutnost algi s posebnim naglaskom na dijatomeje na sedrenim barijerama rijeke Krke u Sloveniji. Cilj je bio utvrđivanje kvalitativnog sastava i relativne brojnosti perifitona. Tijekom 1999. i 2000. mjereni su temeljni fizikalni i kemijski parametri. Utvrđen je 81 takson algi. Većina pripada u Bacillariophyceae. Petnaest vrsta i podvrsta bilo je novo za Sloveniju, od čega 14 spada u Bacillariophyceae i 1 u Cyanobacteria. Većina novih vrsta i podvrsta pripadalo je rodovima Nitzschia (5) i Navicula (4)
