Temporal and spatial distribution of planktic cyanobacteria in Lake Kastoria, Greece, a shallow, urban lake

Abstract

The temporal and spatial distribution of planktic cyanobacteria and some environmental parameters were studied in the shallow, urban Lake Kastoria, Greece from June 1996 to June 1997. Water temperature varied from 6–27 °C, pH from 7.5–8.9 and dissolved O2 concentration from 0.7–12 mg m‐3 10‐3. The mean annual Chl a concentration was 83 mg Chl a m‐3 indicative of the eutrophic‐hypertrophic state of the lake. Cyanobacterial biomass ranged from 11–238 g FW m‐3, constituting about 90% of the total phytoplankton biomass throughout the year. Cyanobacterial biomass was non‐uniformly distributed both vertically and horizontally from August to November 1996 and resulted mainly from the distribution of Microcystis. Seven cyanobacterial taxa were reported for the first time in Lake Kastoria. Six taxa were dominant: Microcystis aeruginosa, M. flos‐aquae, M. novacekii. Limnothrix redekei, Anabaena sp. and Cylindrospermopsis raciborskii. The dominant cyanobacterial taxa can be grouped on the basis of their distribution patterns (1) Microcystis species: maximum biomass occurring at pH > 8, temperature 12–17 °C, depth < 0.2 m; (2) Anabaena sp. and Cylindrospermopsis raciborskii: maximum biomass at temperatures 23–26 °C; (3) Limnothrix redekei: maximum biomass at temperatures 6–27 °C. Usually, non‐uniform, vertical distributions of cyanobacterial biomass were associated with the formation of temperature, pH and O2 gradients. L. redekei was considered to be a key lake organism since it contributed up to 59% of the cyanobacterial biomass. Interestingly, three of the dominant cyanobacteria Microcystis aeruginosa, Anabaena sp. and Cylindrospermopsis raciborskii belong to genera that include toxin‐producing species.

Toxic Cyanobacteria in Greek Freshwaters, 1987—2000: Occurrence, Toxicity, and Impacts in the Mediterranean Region

“…Over these periods the water temperature varied from 5. In the following subsections some previously published data for the period June 1996 Ϫ June 1997 [59] is supplemented with original data from the case study 1. to highlight seasonal patterns (and annual trends) of cyanobacterial and MCYST-LR occurrence and 2. to investigate differences in the biovolumes of individual cyanobacterial species between years using a discriminant analysis of original data, in order to get a contemporary picture of the situation in L. Kastoria.…”

“…Data from June 1996 until June 1997 [59] is here supplemented with original data from 1994 and 1995 to examine annual and seasonal trends. Total cyanobacterial biovolume in lake water ranged from 12...7585 µL L Ϫ1 at inshore and from 11...238 µL L Ϫ1 at offshore stations and constituted 90 % (v/v) or more of the total phytoplankton biovolume.…”

“…Subsequently, the temporal and spatial variation of planktic cyanobacteria, MCYST-LR concentration and some environmental parameters were studied in L. Kastoria from April to November 1994, June to November of 1995, and June 1996 to June 1997 [27,59]. Over these periods the water temperature varied from 5.…”

“…Sampling procedures, identification of cyanobacterial species and determination of cyanobacterial biovolume (total and of individual species) were carried out according to procedures described in [59]. Intracellular (cell-bound) MCYST-LR concentrations were measured using standard HPLC techniques [63].…”

Taxonomic and phylogenetic evaluation of Limnothrix strains (Oscillatoriales, Cyanobacteria) by adding Limnothrix planktonica strains isolated from central China

“…Limnothrix populations are also known to be present in marine environments in South Africa (Silva & Pienaar, 2000). L. redekei populations in Europe have been frequently reported to be massively present in shallow eutrophic lakes for decades (BaileyWatts, 1972;Rojo & Cobelas, 1994;Vardaka et al, 2000;Moustaka-Gouni et al, 2007). Along with the development of molecular phylogenetics in Cyanobacteria, a few strains of L. redekei were shown to be polyphyletic.…”