Phytoplankton of Šasko Lake and the First Record of Invasive Toxin-Producing Cyanobacterium Cylindrospermopsis Raciborskii (Woloszynska) Seenayya Et Subba Raju, 1972  in Montenegro

Abstract

Shallow lakes are specific aquatic systems sensitive to eutrophication, due to the constant exchange of nutrients between sediments and water column and less capacity to buffer external nutrient loading. The aim of this work was to analyze phytoplankton community in Šasko Lake after the gap of almost 40 years. A total of 88 phytoplankton taxa belonging to seven divisions were identified in Šasko Lake during the warm period of year (spring and summer) in 2016. Phytoplankton composition and abundance didn't show spatial heterogeneity, due to the small surface of the lake and wind action, but seasonal differences were observed. Spring period characterized numerical dominance of B and E functional groups of phytoplankton (codons), while summer period characterized higher species diversity and abundance in comparison to spring and dominance of B, P, Sn and H1 codons. Results showed significant increase in phytoplankton abundance (for about two orders of magnitude) as well as the increased percentage share of cyanobacteria in comparison to former investigations. Besides, for the first time, invasive, potentially toxic cyanobacteria Cylindrospermopsis raciborskii (Woloszynska) Seenaya & Subba-Raju was recorded in Montenegro.