Phytobenthos in Lithuanian rivers and its employment for the assessment of the ecological status of rivers

The aim of the study was to investigate species diversity, ecology of phytobenthos in the Lithuanian rivers, to ascertain the indicative merits of phytobenthos parameters in assessing the river ecological status. The investigations were carried out in detail in 73 Lithuanian rivers for the first time, the analysis of taxonomic, ecological groups composition, the development peculiarities were determined, the checklist of species were compiled. New to Lithuania 43 benthic algae were identified, detailed descriptions with authentic pictures, morphometric data, the distribution of species were presented. The first data on genetic diversity of macroalgae in the Lithuanian rivers were obtained, predominant and rare in rivers algae were identified, genetic polymorphism of dominant in river Cladophora glomerata was ascertained. Environmental factors, determining the development of phytobenthos were investigated. For the preliminary assessment of the status of rivers in situ, the indicator species of macroalgae were selected, their coverage values (%) were indicated. According to EU WFD requirements the results on the assessment of ecological status of the Lithuanian rivers ascertained based on phytobenthos index (BI) parameters are important in the assessment, prediction of the changes in ecological status of the Lithuanian rivers and in nature conservation programmes