Application of TBI index in the ecological status assessment of the shallow eolian Lake Ludaš (Serbia)

Abstract

Shallow saline lakes are unique habitats, highly susceptible to negative effects of climate change and adverse anthropogenic activities Recently, several indices, including a trait based index ( have been developed for the assessment of their ecological status The TBI index is calculated as a ratio of traits (diatom groups) that indicate good or excellent ecological conditions (motile species with small cell size and more elongated valves) and traits that are related to degraded ecological status (low and high profile ecological guilds and planktic life form) We tested the applicability of the TBI index in Lake Luda š that was originally an alkaline saline lake Epiphytic diatoms together with water samples for chemical analyses, were collected in June 2019 at the southern part of the lake where a dense population of Ceratophylum demersum was observed A total of 35 diatom taxa were identified in this hyposaline lake The highest number of species belonged to the genus Nitzschia Typical sodic water taxa for this part of the Pannonian Plain, such as Nitzschia austriaca Navicula veneta and N wiesneri were not observed Instead, species characteristic for disturbed saline habitats, for example Navicula wendlingii and Tabularia fasciculata, were recorded In Lake Luda š functional groups of diatoms connected with high conductivity reached only one third of the total abundance On the other hand, a higher percentage of low and high profile guilds and planktic diatoms were recorded Consequently, the TBI index indicated the low ecological status of Lake Luda š and confirmed the negative effect of a disturbed hydrological regime