Monitoring a newly re-born patient: water quality and cyanotoxin occurrence in a reconstructed shallow Mediterranean lake

Abstract

Lake Karla (Central Greece) is a unique example -at European scale -of a shallow lake ecosystem that was dried in the 1960s and in 2009 started to be restored. The lake is listed in the network of the Greek protected areas as it is considered a vital aquatic ecosystem, in terms of biodiversity. It has, however, already been adversely affected by both agricultural and industrial land uses in the surrounding area, leading to eutrophication and shifting algal community towards bloom-forming toxic cyanobacterial species. After repeated heavyblooms, cyanotoxin occurrence and mass fish kills, the local ecosystem management authority has implemented a water quality monitoring program (July 2013 -July 2015) to assess environmental pressures and the response of aquatic biota in the lake. Microscopic, immunological, and molecular techniques combined with physico-chemical parameters, complemented by liquid chromatography tandem mass spectrometry (LC-MS/MS), were used to monitor cyanobacteria blooms and the associated cyanotoxin production from three different sites in Lake Karla and from the adjacent Kalamaki Reservoir. Water quality was also assessed by the structure of benthic invertebrate community on the sediment. Cyanobacteria were the main phytoplankton component, representing more than 70% of the total phytoplankton abundance; dominant taxa belonged to Cylindrospermopsis raciborskii, Limnothrix redekei, Anabaenopsis elenkinii, and Microcystis spp. Euglenophytes (Euglena), diatoms (Nitzschia), and chlorophytes (Scenedesmus) were also important phytoplankton constituents. LC-MS/MS confirmed the co-occurrence of microcystins, cylindrospermopsin, saxitoxin, neo-saxitoxin and anatoxin-a. The occurrence of cyanotoxins in relation to the persistent and dominant cyanobacteria and the impact of cyanobacterial harmful algal blooms on the newly constructed lake along with the land uses and the emergent mitigation measures are discussed.

Cyano-assassins: Widespread cyanogenic production from cyanobacteria

“…The polyphasic taxonomy applied to the strains of this study revealed taxa known to be part of bloom-forming communities ( Sphaerospermopsis and Nodularia), rock-dwelling communities ( Scytonema and Tolypothrix ), and hot spring cyanobacteria mats ( Desertifilum and Gloeotrichia ) (Dadheech et al, 2014; Mazur-Marzec et al, 2015; Gkelis et al, 2017; Joanna and Andrzej, 2018). Our results revealed the presence of taxa not previously described from Greek habitats (Gkelis et al, 2016), such as Allinostoc (Saraf et al, 2018) and Oculatella (Osorio-Santos et al, 2014) and taxa previously described only from the tropical zone like Komarekiella and Kovacikia (Miscoe et al, 2016; Hentschke et al, 2017).…”

Diversity, Cyanotoxin Production, and Bioactivities of Cyanobacteria Isolated from Freshwaters of Greece

“…The polyphasic taxonomy applied to the strains of this study revealed taxa known to be part of the bloom-forming communities in Greece, such as Microcystis and Limnothrix [23,24,25] and others, such as Chlorogloeopsis fritschii , Desmonostoc muscorum , Nostoc elgonense , and Nodosilinea sp., which were reported for the first time in Greek freshwaters [21].…”

“…Microcystins were found in nearly 70% of the Microcystis strains examined in this study, thus providing further evidence that cyanobacteria blooms in Greece, often dominated by Microcystis spp., are highly likely to contain microcystins [23,24,25,43]. All MC-producing Microcystis strains from the present study were isolated from Pamvotis Lake, in northwest (NW) Greece [22].…”

Can cyanobacteria infect underground water sources? Evidence from a small scale monitoring of natural mineral water drinking source

“…At present, none of the European countries have established monitoring program for cyanotoxins in potable minerals waters so far, and only some countries have done so for drinking water such as Spain, France, the Czech Republic and Poland (Burch, 2008). In Greece, there are very few official monitoring programs in place (Kaloudis et al, 2013;Gkelis et al, 2015a) for cyanobacterial blooms and toxins produced in freshwaters, whereas there is also no legisla- tion with regard to monitoring of these quality parameters (Cook et al, 2005). Moreover, there are no legally established maximum allowable concentrations for cyanotoxins in potable mineral water.…”