Microcystin concentration in fishpond waters

Cyanobacterial blooming is a worldwide problem which sometimes results in cyanotoxin production. Most commonly produced cyanotoxins are microcystins (MCs), potent inhibitors of protein phosphatases. Protein phosphatase 1 (PP1) is known to be involved in the regulation of a variety of cellular processes. In this study, MC concentration was assessed via inhibition of protein phosphatase 1 (PP1 assay) in water samples taken from 14 lakes of Mužlja fishpond, Vojvodina, Serbia. During the summer of 2011, cyanobacterial growth occured in the fishpond lakes and small, planktonic crustacean Daphnia sp. was used to control or/and prevent further development of cyanobacteria. Different MC concentrations (calculated as microcystin-LR equivalents) were detected, mostly depending on the occurrence and grazing of Daphnia sp. More thorough monitoring of fishponds should be conducted, both in Serbia and around the world, in order to gain more precise estimation of cyanotoxin concentrations and their accumulation in organisms used for human consumption and thus prevent possible negative health effects. [Projekat Ministarstva nauke Republike Srbije, br.176020

Cyanobacteria in aquatic ecosystems in Serbia: effects on water quality, human health and biodiversity

<div><p>Cyanobacterial blooms and toxins (cyanotoxins) in both natural and controlled waterbodies are of worldwide concern. This paper presents a review of 130 years of research on the biodiversity, occurrence and toxicity of cyanobacteria in waterbodies throughout Serbia, as well as their effects on water quality and human health. Data on the occurrence of particular cyanotoxins over more recent years are also collated. Data from over 70 sources, including research articles, project reports, conference abstracts, dissertations, books, annual and news reports are summarized. This survey provides a valuable resource for current and future assessments of cyanobacterial and cyanotoxin occurrence and abundance in Serbian waterbodies, and for management solutions where ecosystems and human health are jeopardized.</p></div

Does the Kis-Balaton Water Protection System (KBWPS) effectively safeguard Lake Balaton from toxic cyanobacterial blooms?

Lake Balaton is the largest shallow lake in Central Europe. Its water quality is affected by its biggest inflow, the Zala River. During late 20th century, a wetland area named the Kis-Balaton Water Protection System (KBWPS) was constructed in the hopes that it would act as a filter zone and thus ameliorate the water quality of Lake Balaton. The aim of the present study was to test whether the KBWPS effectively safeguards Lake Balaton against toxic cyanobacterial blooms. During April, May, July and September 2018, severe cyanobacterial blooming was observed in the KBWPS with numbers reaching up to 13 million cells/mL at the peak of the bloom (July 2018). MC- and STX-coding genes were detected in the cyanobacterial biomass. Five out of nine tested microcystin congeners were detected at the peak of the bloom with the concentrations of MC-LR reaching 1.29 mu g/L; however, accumulation of MCs was not detected in fish tissues. Histopathological analyses displayed severe hepatopancreas, kidney and gill alterations in fish obtained throughout the investigated period. In Lake Balaton, on the other hand, cyanobacterial numbers were much lower; more than 400-fold fewer cells/mL were detected during June 2018 and cyanotoxins were not detected in the water. Hepatic, kidney and gill tissue displayed few alterations and resembled the structure of control fish. We can conclude that the KBWPS acts as a significant buffering zone, thus protecting the water quality of Lake Balaton. However, as MC- and STX-coding genes in the cyanobacterial biomass were detected at both sites, regular monitoring of this valuable ecosystem for the presence of cyanobacteria and cyanotoxins is of paramount importance