Algal Communities Along the Sava River

Abstract

Field analysis of phytoplankton and phytobenthos communities of the river Sava has been performed, from Slovenia to Serbia, in August 2011 and September 2012 at 20 localities. A total number of 256 taxa have been determined, from eight divisions: Cyanobacteria (20), Rhodophyta (1), Dinophyta (6), Cryptophyta (1), Chrysophyta (1), Bacillariophyta (152), Chlorophyta (67) and Euglenophyta (8). In the phytoplankton samples, 188 taxa have been identified and in the phytobenthos samples 153 taxa. The most diverse divisions of phytoplankton of the river Sava were Bacillariophyta (46.28 % of total taxa number) and Chlorophyta (34.57 % of total taxa number). Biomass of phytoplankton was low, and the abundance of phytoplankton communities varied between 65,000 and 412,000 Ind L−1. The biomass of phytoplankton of the river Sava was in the range of 41 to 564 μg fr. wt. L−1. The phytobenthos dominated by the division of Bacillariophyta, making 81.7 % of the community. Visible macroaggregations were composed of Cladophora glomerata (Chlorophyta) and Thorea hispida (Rhodophyta).